PROGRAM INSTRUCTION MANUAL - storage.googleapis.com · perform exte nsive traction power system load flow studies for the MBTA Green and Red Lines in Boston, Massachusetts. After

April 2, 2016

Electric Traction System Analyzer

DC TRACTION POWER SYSTEM ANALYSIS SOFTWARE

PROGRAM

INSTRUCTION

MANUAL

April 2, 2016

VPS Version 2.2p TPLF Version 9.3

ETSA INSTRUCTION MANUAL INTRODUCTION TO ETSA

April 2, 2016

Electric Traction System Analyzer

Program Instruction Manual

Version 1.05

Table of Contents

Page I Introduction to ETSA ..................................................................................................... 1

II Vehicle Power Simulator Program (VPS) ...................................................................... 7

III Traction Power Load Flow Program (TPLF)................................................................ 16

IV TPLF Voltage Profiling Program (VOLTPRO) ............................................................. 30

V Rail Potential Modeling ............................................................................................... 32 V Miscellaneous TPLF Procedures ................................................................................ 35

VI TPLF Output Chart Examples ..................................................................................... 37

Written by R. W. Benjamin Stell, P.E. for the www.traction–power-resource-page.com web site.

http://www.traction%E2%80%93power-resource-page.com/


Page 1 April 2, 2016

I. Introduction to the Electric Traction System Analyzer Simulation Software

Summary The Electric Traction System Analyzer (ETSA) is a suite of interrelated computer programs that has been used extensively for the analysis and design of direct current (dc) traction power systems. Its original development in the mid-1980’s was the byproduct of consulting engineering assignments, MSEE degree coursework and research performed by R. W. Benjamin Stell. The research work was initially prompted by Mr. Stell’s experiences using other commercially-available software ("TOM Programs") to perform extensive traction power system load flow studies for the MBTA Green and Red Lines in Boston, Massachusetts. After expending significant effort trying to adapt the limitations of these three-phase ac power system-based analysis programs to the unique requirements of dc traction power system modeling, Mr. Stell began development of an entirely new simulation suite written in a more structured programming format. The first application for the resulting ETSA software was to complete the system-wide light and heavy rail traction power system planning and design studies for the MBTA Traction Power Upgrade Project (Red, Green, Orange and Blue Lines). As part of this upgrade project, ETSA simulation accuracy was correlated against substation rectifier and feeder currents and train voltages and currents using strip-chart recorders for the Red (heavy rail) and Green (light rail) lines ETSA is a dynamic load flow simulator that has the capability to accurately and efficiently simulate large and complex dc traction power electrical networks in addition to modeling the performance of transit vehicles. ETSA simulates in detail the time-varying power flows due to the scheduled movements of electrified transit vehicles including light rail, heavy rail, electric trolley bus and automated people mover (APM). Notable ETSA features include the explicit and simultaneous modeling of both the positive and negative return electrical networks, as well as calculation of:

Load currents throughout the positive and negative return traction electrical networks;

Power and energy regenerated into the electrical system during braking;

System receptivity to regenerated power;

System energy losses in individual system components as well as in aggregate;

Positive and negative return conductor and equipment load currents;

Voltage at the trains, as well as any other location on the traction power system;

The impact of reduced voltage on vehicle input power (forced reduced performance);

Steady-state short circuit currents at any location on the system;

Rail-to-earth voltages at trains and at fixed locations along the tracks; and

Substation metered demand and energy consumption.

Graphical profiles (plots) of vehicle voltage versus position, current flow in electrical conductors, overhead contact system wire temperature versus time, and substation power consumption versus time can also be produced. The load flow program provides fast, direct solutions of system equations and an essentially unlimited capacity for the number of power system components that can be modeled simultaneously. ETSA is an ideal traction power system simulator for rail systems that do not require detailed modeling of “real-time” interaction between signal systems and rail vehicles. In its current state it is first and foremost a large-network traction power load flow simulator rather than a sophisticated signal system and/or operations simulator. Although this characteristic may preclude its use on certain projects where vehicles do not observe regular headways, it enables answers to be obtained quickly and economically with sufficient accuracy for most applications. The operation of electrified transit systems normally involves a considerable amount of probability with regard to vehicle schedules, vehicle locations,



operator idiosyncrasies, auxiliary loads, source voltages, conductor temperatures, contact system wear, and other variables which affect the performance of the system. It can be argued that the additional effort required to model signal system behavior in detail for purposes of obtaining load flow results may in many cases not be warranted, unless many cases are simulated in an effort to “bound” the potential variations of these parameters. Introduction The accurate analysis and planning of large traction power systems presents the engineer with a formidable task. There is no system "steady state", that is, the major loads on the power system are physically moving as well as changing in magnitude with time. Trolley wire temperatures increase and decrease as trains approach and pass. For systems employing regenerative braking of transit vehicles, the analytical challenge is compounded by the one-way power flow through the substation rectifiers typically in use today. Moreover, the amount of regenerated power actually utilized at a given instant is dependent on the position and magnitude of other loads and regenerating vehicles at that instant. Energy delivery to a substation is sensitive to rectifier transformer tap settings at that and at neighboring substations. Power is continually exchanged between neighboring substations as dc bus voltages vary under changing loads. This presents a dynamic load flow problem that requires an analytically advanced solution on a large scale, incorporating the entire interconnected traction power system being studied into one computer model. The core ETSA software was originally developed between 1985 and 1987 specifically to address this need for fast, accurate simulation of large power system electrical networks while utilizing the economical personal computer environment. ETSA consists of two main simulation programs, the Vehicle Power Simulator and the Traction Power Load Flow, plus several support programs. Together, these simulate in detail the energy consumption and schedule performance of transit vehicles, and the combined effect of the moving vehicle loads and fixed (stationary) loads on the traction power system components. Technical Description - Vehicle Power Simulator The Vehicle Power Simulator converts transit vehicle and corridor input data to an output file containing train power consumption (or regeneration), position, speed, acceleration and tractive effort versus time. This output file, known as a vehicle "load profile", contains the detailed simulation of one or more vehicles moving along a particular route or rail corridor in accordance with the various constraints imposed upon it by propulsion system tractive effort, aerodynamic and friction forces, gradient forces, speed restrictions, and passenger load factor (weight). The input data used to generate the load profile includes files of right-of-way gradient, curvature, speed limits, passenger station locations, track numbering conventions, and vehicle/train data. The vehicle data includes propulsion system speed/tractive effort/efficiency curves plus vehicle weight and resistance data. The Vehicle Power Simulator is used to create a load profile for each type of vehicle/train consist to be simulated on a given track or combination of tracks. These load profiles are then used as input to the Traction Power Load Flow program. Technical Description - Traction Power Load Flow The Traction Power Load Flow (TPLF) is an extremely fast and powerful electrical network simulator capable of solving very large traction power electrical network models. Written by a traction power systems analysis specialist, it is a product of decades of experience with both traction power and electric utility system analysis and design. It is unusual as compared to other related industry programs by virtue of its ability to simultaneously solve in detail both halves of the direct current traction power system; from the cathode of the rectifier to the vehicle (the positive supply network), and from the vehicle back to the rectifier anode (the negative return network). These two networks are represented in the Traction Power Load Flow by an assembly of "branches" and "nodes", which are used to model individual or combined pieces of equipment. Those who have used SPICE type electric network simulation programs will be



familiar with this approach. A branch is any conductor (wire, cable, bus bar, third rail, running rail, etc.) that can be modeled as a linear resistance, and a node is simply one end point of a branch. Parallel conductors can be explicitly modeled as separate branches, if desired, or combined into equivalent conductors. Rectifiers are modeled as branches with a variable resistance which increases with high forward load current in a manner specified by the user. The alternating current (ac) sides of rectifiers are modeled as Thevenin equivalents of the connected ac power sources (typically, an electric utility). Any conceivable configuration of electrical equipment can be efficiently simulated to the desired degree of detail, due to advanced solution and memory management techniques incorporated into the software. For example, the Traction Power Load Flow can be used to perform detailed stray-current and rail voltage rise analyses for rail systems by judicious selection and combination of equivalent resistances for earth, rail-to-earth interfaces, and buried structures in the vicinity of the right-of-way. The present version of the Traction Power Load Flow is designed to solve systems of up to 950 nodes and 1500 branches, and these dimensions can be extended, if necessary. The Traction Power Load Flow performs a time-based simulation of a traction power system. This involves the selection by the user of a time period over which the simulation will occur, plus the scheduling of the desired vehicle or train dispatches during this period. These vehicle dispatches are scheduled by a timetable in an input data file. During the simulation time period, the Traction Power Load Flow moves scheduled trains along their respective routes according to the train movement simulation information contained in the appropriate power profiles. At regular, user-selected time intervals (typically, every second), new network nodes are created for each vehicle or train at their proper location on the power system, the initial electrical load or regenerated currents are determined from the power profiles, and a network solution ("snapshot") is performed. Depending on whether a voltage-dependent train model is selected by the user or if the train is regenerating current into the system, further network solutions may be performed to arrive at a solution based on an adjusted vehicle or train load. Results from each "snapshot" are written to up to seven different output text files for review and further processing using either commercial spreadsheet programs or ETSA support programs. Information derived from each snapshot is also stored and managed internally to produce a comprehensive summary report file at the end of the simulation. Major features and capabilities incorporated into the present version (Version 9) of the TPLF program include the following:

Creation of the electrical network model database is straightforward and efficient. All electrical equipment data is input and stored in ohms (not the per unit system), and input data is automatically crosschecked with errors reported and located in the database. Rectifier transformer tap settings and primary/secondary turns ratios are input in volts, with individual settings allowed for each rectifier transformer in the network. Quantities representing actual voltage regulation test data (regulation curves) are input to describe rectifier transformer voltage regulation as a function of rectifier load current.

Input data files are “free format” text files, enabling easy manipulation of data as well as ample room for user notes.

Individual electrical network branches (conductors) and rectifiers can be temporarily removed from service for the simulation of outages by a simple entry in the corresponding database field. The corresponding fields in the simulation output are then marked "out".

Instantaneous voltage drop, peak current, rms current and average current flow and energy loss are calculated for any selected conductors in the electrical network.

Modeling of thryristor controlled rectifier (TCR) ac-to-dc converter voltage-current characteristics is possible. Typical TCR characteristics include a “flat” voltage-current output curve between 0 and 100% of rated current followed by a linear characteristic to 300% of full load current. The TPLF program can model any converter voltage-current characteristic that can be represented by a piecewise linear curve with four regions: 0 to 100%, 100-200%, 200-300%, and 300-450% of full load current. Each converter can have a unique voltage-current characteristic.



Instantaneous train voltage, substation power consumption, rectifier current and currents in selected electrical conductors and equipment are calculated for each time interval in a simulation, and stored in data files for plotting and further manipulation. For example, the support program VOLTPRO will read the stored train voltage data to produce profiles of lowest train voltage versus train position along the right-of-way for a specific train. A support program WIRETEMP produces profiles of trolley wire or messenger temperature versus time for selected locations.

The electrical network equations, which represent both the positive and negative return halves of the dc network, are solved directly by sparse matrix numerical techniques (not the brute-force and much slower direct matrix inversion). This method of solution is greatly superior to the typical "iterative"-type, which slows down and often fails to converge on a solution as the network size increases or as voltage falls well below system nominal.

The overall energy consumption of the power system and the ratio of total system energy losses to the total system energy consumed are calculated. These quantities can be used to quantify the benefits of various energy loss reduction strategies.

The total energy consumed as losses in the power system, in kilowatt-hours, is calculated and classified according to the location of occurrence in the positive dc network, the negative return network, the rectifier transformer load losses and no-load losses.

The receptivity of the traction power system to power available from regenerative braking (receptivity to regeneration) is calculated when regeneration is in use. Receptivity to regeneration is the ratio of the regenerated power actually absorbed by the power system to the power that could be produced by regeneration. This ratio provides a measure of how much of the available regenerated power is actually being utilized.

Peak demand is calculated for individual substations, or for any desired coincident combination of substations, for 15 and 30 minute demand intervals.

Transit vehicle electrical loads can be modeled as either constant-current (no variation of load with line voltage) or as linearly voltage-dependent. The latter option is used for modeling vehicles with “forced reduced performance” (FRP) capability. Vehicles with FRP reduce their propulsion current demand when line voltage drops below a trigger threshold. The reduction in propulsion current demand, or current “taper”, is typically a linear function of voltage expressed in amps per volt.

Rail-to-earth voltage is calculated for each rail vehicle on the traction power network, and can be plotted versus vehicle position on the right-of way if desired.

Description of Traction Power Load Flow Output The Traction Power Load Flow produces a wide variety of output for immediate analysis as well as further processing. A total of seven different output files may be produced from each simulation, depending on the information needs of the user. These are the Summary, Train Voltage, Snapshot, Substation Power, Rectifier Current, Node Voltage, and Ammeter Output files. The Summary Output file is always created during each simulation while the remaining six are created at the discretion of the user, avoiding the production of reams of unnecessary paper or data storage when simulation results for a long time period are desired. Each file is stamped with its file name and date of creation to simplify identification and record keeping. All output files, with the exception of the Summary, Snapshot and Node Voltage, are created in "delimited" text file format to enable them to be imported into common spreadsheet, database and presentation graphics programs.

Summary Output File

This contains highlights of a particular traction power system simulation and confirms important input parameters, including: descriptive text from the headers of various input files; location of the lowest calculated train voltages as well as the instant of time (simulation snapshot) at which they occurred;



highest rail-to-earth voltages; instantaneous peak and time-varying ac and dc current flows and energy losses; substation peak and average power flows, and substation energy consumption. If regeneration of power from vehicles into the traction power system is detected during a simulation, information on regenerated energy and system receptivity to regeneration is reported. Coincident and noncoincident system peak power demand is also reported for 15 and 30 minute demand intervals if the simulation time exceeds the respective interval.

Train Voltage Output File

This file contains an uninterrupted listing of all calculated train voltages and associated train location and power section resulting from a simulation. The listing is ordered according to the instant (snapshot) at which the train voltages were calculated, according to the simulation "clock". This file is used primarily as input to the ETSA program module “VOLTPRO” which creates profiles of train voltage and rail voltage versus position for individual trains as they move through the power system. The voltage profiles are stored in a format suitable for plotting by means of spreadsheet or presentation graphics programs.

Snapshot Output File This contains detailed information on train voltages and current draw, ac and dc power system voltages, current flows, power consumption and losses for each time interval (snapshot) calculated during a simulation.

Substation Power Consumption Output File

This file contains a column of calculated substation ac power consumption versus snapshot time for each traction power substation, plus a column which sums all substation loads for each snapshot. At the bottom of the file, coincident system and noncoincident system and substation peak power demands are calculated for 15 and 30 minute demand intervals.

Rectifier Current Output File

This contains a column of simulated rectifier current flow versus time for each snapshot in a given simulation. The data is used primarily for plotting purposes and for rectifier loading analysis. The column headings are the rectifier cathode node names associated with the rectifier currents being calculated.

Ammeter Output File

This file contains columns of simulated conductor currents versus time for each metering point requested by the user. This information is used for plotting individual conductor currents and for conductor transient temperature analysis, which is performed by the WIRETEMP support program module. The column headings are the branch names and the milepost locations associated with each metering location.

Node Voltage Files

Two files of node voltage data are produced. The first sequentially lists the calculated voltage at every electrical node in the electrical network, for every simulation "snapshot". Such information is extremely helpful in finding the causes and magnitudes of voltage drops anywhere in the traction power distribution network. The second file, named “node_volts.prn”, is automatically generated whenever rail-to-ground resistances (circuits) are being used. This provides the node voltage data in columns suitable for plotting, and is intended for rail-to-earth voltage analysis. Summary The Electric Traction System Analyzer is a versatile, proven tool for traction power systems analysis and design. ETSA continues to be enhanced to meet new analytical challenges and project needs. It has been utilized to date in systems studies for various transit properties as described in the table below.



Property Route Description

Massachusetts Bay Transportation Authority

Boston, MA

Red Line 600 Vdc heavy rail line with two branches at southern end (system upgrade study)

Green Line 600 Vdc light rail line with Central Subway and four radial branches (upgrade study)

Blue Line 600 Vdc heavy rail line with contact rail in tunnel, catenary outside the tunnel (upgrade study)

Orange Line 600 Vdc heavy rail line with third express track at northern end (upgrade study)

Greater Cleveland Regional Transit Authority Cleveland, OH

Red Line 600 Vdc heavy rail line, catenary-powered (upgrade study)

Waterfront Line 600 Vdc light rail line, electrically interconnected with Red Line (preliminary design study)

New Jersey Transit Newark, NJ

Hudson-Bergen Light Rail: Bayonne 8th St.

Extension

Preliminary design study to size substation and power distribution equipment for a 750 Vdc light rail line light rail extension project (2006).

Chicago Transit Authority, Chicago, IL

Red, Blue, Orange, Green, Purple, Brown

& Yellow Lines

Systemwide study of all seven existing 600 Vdc heavy rail rapid transit lines. Entire interconnected traction power system including the central elevated “Loop” was modeled (2004)

Maryland Transit Administration, Baltimore,

MD

Central Light Rail 750 Vdc light rail line with spurs to BWI Airport and Baltimore Penn Station. System-wide upgrade studies were performed for the original system, for the extensions, and for the Double Track Project.

Washington Metropolitan Area Transit Authority

(WMATA), Washington, DC

Red, Blue and Orange Lines

Existing 750 Vdc heavy rail system (energy conservation/electric rate study)

Blue Line Largo Extension

New 3 mile extension to an existing line (design-build competition)

Los Angeles County Mass Transit Authority, CA Arroyo Seco LRT New 750 Vdc light rail system (design-build

competition) Chicago Transit Authority,

Chicago, IL Red/Dan Ryan Line Existing 600 Vdc heavy rail line electrically interconnected with other lines

Chicago Transit Authority, Chicago, IL

Brown/Ravenswood Line

Existing 600 Vdc heavy rail line electrically interconnected with other lines

Hartsfield-Jackson Atlanta International Airport CONRAC APM New airport people mover (APM) design-build

project utilizing 750 Vdc traction power (2004) Hampton Roads Transit

Norfolk, VA “Tide” LRT Line New 7.4 mile 750 Vdc light rail starter line (2007)

Bay Area Rapid Transit (BART)

SVBX Extension to Berryessa

RFP design verification for 1000 Vdc heavy rail extension project design-build proposal

Dallas Area Rapid Transit (DART)

Orange Line Extension to DFW

Airport

RFP design verification for 750 Vdc light rail extension project design-build proposal, using TCR substations.

Charlotte Area Transit System, Charlotte, NC Blue Line Extension

Load flow studies to support final design of a 9.4 mile, 750 Vdc light rail extension plus power upgrades for the existing starter line.

Region of Waterloo, Ontario Stage 1 LRT Load flow studies to support the design-build of a new 16 km LRT line.

ETSA INSTRUCTION MANUAL VPS PROGRAM


II. Vehicle Power Simulator Program (VPS) This section describes the application of the Vehicle Power Simulator program (VPS). The VPS program simulates the movement and power consumption of transit system vehicles such as light rail, heavy rail rapid transit, automated people mover (APM) and electric trolleybus. Power supply can be either ac or dc. It is a “train performance calculator” type program, designed primarily to generate the train performance electrical data required for the Traction Power Load Flow Program, although it can be used as a stand-alone application.

The Vehicle Power Simulator determines the power consumption in Watts at regular time intervals as a single vehicle, or a train of similar vehicles, moves along a mathematical model of an alignment or route. The alignment model consists of gradient and curvature data, speed limits, stop locations, and positive and negative return contact system identifiers.

Program input is currently handled via a combination of free-format "text" (ASCII) data files. These files describe the vehicle electrical and mechanical characteristics, and the alignment model. All input files are normally prepared using spreadsheets and/or a text editor such as “Wordpad”. Program output is also in text file format.

Current Operating Systems Supported VPS_public.EXE is currently a Windows application program that will run under the Windows XP or later Windows operating systems. It is typically executed (run) from inside the Windows Explorer program by double-clicking on the VPS program filename. This method is recommended since it allows input data to be viewed and edited simultaneously inside "tiled" Explorer windows.

Technical Basis and Underlying Major Assumptions 1. A vehicle or train of vehicles is represented as a single point located at the center of the vehicle

or train. This center point is used to determine the applicable right-of-way gradient, curvature and track numbering values.

2. Train speed at a speed change location takes the length of the vehicle or train into account. The front of a train heading into a lower speed limit will be traveling at the lower speed when it crosses the speed change point. The rear of a train heading into a higher speed limit will remain at the lower speed until it reaches the higher speed change point.

3. All alignment data must be input to the program in the form of continuous mileposts, which can be positive or negative (similar to the arrangement of a number line whose center is zero).

4. All vehicles in a train must be of the same vehicle type.

5. Internal calculations of vehicle performance and energy consumption are executed at regular 1/10th second intervals.

6. Train resistance is modeled in accordance with the Davis Equation as presented in the Railroad Engineering text by William W. Hay (curve resistance units are lbs/ton/degree of curvature).

7. Vehicle tractive effort is converted to electrical Watts by interpolation between four curves of speed vs. tractive effort vs. efficiency curves provided by the user. This enables a vehicle to have different efficiencies at one speed for different levels of tractive effort. A similar fifth curve provides efficiencies for regenerative braking, and a 6th curve the power factor for ac-powered vehicles.

8. When regenerative braking is “on”, the full available power (watts) is written to the load profile. The TPLF (load flow) program determines how much of the available regenerated power can be accepted by the power system.

9. The current version of the program uses English (Imperial) units only.



VPS Program Input Requirements The VPS program requires "space delimited" input text files in order to operate. The files are “free-format”, meaning that the data do not have to be in precise locations on each line, but they must be in the correct order, separated by spaces (NOT tabs), and of the correct data type. These files must all reside in the same directory as the VPS_public.EXE program, otherwise they will not be found by the program:

VPS driver file

Station data

Vehicle data

Maximum Speed data

Gradient data

Curvature data

Positive contact system numbering data (for catenary or positive contact rails)

Negative contact system numbering data (for running rails or negative contact rails)

Each of these input files is described below using examples from actual simulations. The example data files, which are from a Charlotte, NC light rail project, are available on the traction power resources web site.

VPS Driver File

This file is the “file organizer” for the creation of a vehicle load profile; one of these “organizer” files is required for each load profile that will be created. The first item on the first line of this file is the desired time interval between all output data points in the load profile, in seconds. It can be any integer or decimal down to a tenth of a second; however, the TPLF program currently accepts load profile data in integer intervals only, so a value of 1.0 seconds is recommended.

The next seven lines contain the input data file names noted above, and the last three lines contain the output file names. The maximum length of each file name is 15 characters, and the filenames must be listed left-justified and in the proper order. The filenames can include any legitimate characters, and similar file extensions can be used for ordering project data.

User notes can be written to the right of the input data in this file, and below it. The example below shows a typical VPS driver file with added user notes; the required data is indicated by bold font. Station Data File

Vehicle Data File Speed Data File

1.0 OUTPUT SNAPSHOT INTERVAL (SEC.) ST-NB.CSC STATIONS DATA: CATS SOUTH CORRIDOR + EXTENSION 3-CAR-DATA.CSC TRAIN DATA FILE: 3-CAR LRV TRAIN (id: OC3IB ) SM-BOTH.CSC SPEEDS DATA GR-BOTH.CSC GRADIENT DATA CU-BOTH.CSC CURVATURE DATA RUP-NB.CSC POSITIVE ROUTES FILE (POS. CONTACT SYSTEM “TRACK” NUMBERS) RUN-NB.CSC NEGATIVE ROUTES FILE (RUNNING RAIL TRACK NUMBERS) SUM-NB.CSC RUN SUMMARY OUTPUT FILE LP-NB.CSC LOAD PROFILE OUTPUT FILE N DET-NB.CSC DETAILED OUTPUT FILE (“N” for none, “Y” for file generation) VPS DRIVER FILE VPS-NB.CSC (NORTHbound 3-car train, Track 1) This file contains the filenames for all input and output data for the VPS Program. Text notes can be typed anywhere on the page except for the left-most 15 spaces on lines containing file names. ALL FILENAMES CAN BE UP TO 15 CHARACTERS LONG.



Stations Data File

Information about station, signal or other vehicle stop locations is contained in the Stations Data File. This information consists of the station or stop name, the center-of-platform milepost, and dwell time (dwell time is the number of seconds the vehicle will remain stopped at the given location).

The first line in each Stations Data File is saved by the program for inclusion in the header of the VPS Load Profile output file. This can be a line of text describing the contents of the file (see example file on the right).

The second line contains a train/route identifier of up to three characters which should be left-justified on the page (“NB” in the example). These letters are concatenated (attached) to the three train identifier letters contained in the Vehicle Data File to make up the train identifier used in the Load Profile. The remaining lines contain the station/stop information for each stop location desired. This

information in this file must be provided (ordered) in the desired direction of vehicle motion (this is how the VPS program determines which direction the vehicles should travel).

The station names must not exceed 15 characters in length, and must be enclosed in apostrophes as shown (these names are “15 character strings” in software parlance).

The stop location milepost value must be a decimal, as must the station dwell time. Starting and ending stations should have dwell times of zero seconds (the program will ignore

any dwell time at the last station in a station file). The final line in the file must contain one or more left-justified exclamation points (this is how the

VPS program knows when to stop reading data). This is a “free-format” type file – no need to be concerned about exact spacing of the data, just

leave blank spaces between the columns.

Vehicle/Train Data File

This file contains all the information pertaining to the vehicles being simulated. An example file is included on the page after next that contains explanatory text in addition to the required data; user notes can be written to the right of the required data (the text to the right of the exclamation points). Other comments and instructions about several of these data items are as follows:

Up to five lines of user notes can be included at the top of the data file, as long as each notation line begins with an exclamation point.

The train type identifier is a character string, and therefore must be bracketed by apostrophes.

The number of speed/tractive effort/efficiency data points tells the program how many lines of data to read; the limit is currently 60 lines (the “counter” must be exact!) Speed is in mph, and tractive effort in lbs-force. The first four pairs of data columns are for motoring mode, the 10th column is for regeneration mode, and the 11th (optional) column is for power factor.

If regenerative braking is to be modeled, a maximum permissible (limiting) value for regenerated amps output PER CAR can be entered where indicated.

The equivalent rotational weight factor is entered as a decimal (NOT in per cent).

!CATS - NB Track 1 Station Location File NB 'I-485' 3.6421 0.000 'Sharon Rd. Wes' 4.5221 20.000 'Arrowood Rd.' 5.7140 20.000 'Tyvola Road' 7.6194 20.000 'Woodlawn Rd.' 8.5126 20.000 'Scaleybark Rd. 9.5961 20.000 'New Bern St.' 10.3005 20.000 'East-West Blvd' 11.3198 20.000 'Rensselaer Ave' 11.6522 20.000 'Carson Blvd.' 11.9747 20.000 'Stonewall/CC' 12.2655 20.000 '3rd Street' 12.5312 20.000 'Trans. Center' 12.7026 20.000 '7th Street' 12.9103 20.000 '9th Street' 13.1429 20.000 'Parkwood' 13.9844 20.000 '25th Street' 14.4660 20.000 '36th Street' 15.2835 20.000 'Sugar Creek' 16.0668 0.000 !!!!



Speed Data File

This file contains sets of location (milepost) and speed limit data pairs that describe the speed limits along a given right-of-way that are applicable to the vehicle being simulated. Each speed limit (entered in mph) applies to the segment defined by the milepost value on the same line, and the next milepost in the increasing direction (see example below). These mileposts can represent signal block boundaries (impedance bonds), or speed limit signs for line-of-sight type systems. Both mileposts and speeds must be entered as real numbers (numbers with decimal points). Mileposts must be entered in increasing units (from lowest to highest). Error-checking is provided to ensure that all values are increasing.

Speed file data mileposts should start and end slightly beyond the first and last mileposts in the Stations Data File (this error will be reported by the program).

The program will use these speeds as maximum speed limits between each pair of associated mileposts. These speeds may be obtained from signal line plans, in which case they could be Maximum Allowable Speeds (MAS), or the speed commands that would be given by an automatic train control (ATC) system when a train is occupying the next block, depending on which would be the most severe condition from the perspective of the power system. Any combination of possible ATC speed commands can be entered into this file; the worst case can then be determined by simulating several alternative speed profiles, and comparing the results.

EXAMPLE VEHICLE DATA FILE !File CAR-DATA.CSC !Contains data for CATS LYNX Per Siemens train performance data !3-CAR train for Charlotte CATS light rail system '3S-' !train type identifier (three characters, max.) 750. !Nominal voltage for calculations OFF !regen status 93.6 !car length (feet, per car) 3 !# of cars per train 35.0 !Line aux. kW per car 67.04 !AW3 full weight: tons per car (134,081 lbs) 6 !number of axles per car 110. !frontal area (sq. feet) (Davis Eq. A coefficient) 0.045 !Wheel flange coefficient (Davis Eq. B coefficient) 0.0024 !Air drag coefficient, lead car (Davis Eq. C coefficient) 0.00034 !Air drag coefficient, trailing car(s) 0.80 !Average curve resistance (lbs per ton per degreee of curvature) 3.00 !Max. acceleration rate (mphps) 2.20 !Max. deceleration rate (mphps)(service braking rate) 0.11 !Equivalent rotational weight factor (factor for additional train weight) DC !Enter DC for dc power, or AC for ac power 0.00 !NOT USED 0. !max regen propulsion amps per car (real component) 14 !# of speed/effort/eff. curve pts (low, low-med, med, high TE + regen eff.) 0.00 500. .50 8000. .50 15000. .55 19109. .600 .50 1.0 !Last column is 5.00 500. .51 8000. .60 15000. .61 19109 .617 .60 1.0 !power factor 10.00 500. .60 8000. .65 15000. .75 19109. .617 .75 1.0 !data 15.00 500. .60 8000. .65 15000. .75 19109. .750 .75 1.0 20.00 500. .75 8000. .85 15000. .87 19109. .870 .80 1.0 25.00 400. .75 4000. .85 10000. .87 15287. .870 .80 1.0 30.00 400. .75 3000. .85 8000. .87 12589. .870 .80 1.0 35.00 300. .75 2500. .85 7000. .87 11016. .870 .80 1.0 40.00 300. .75 2000. .85 5000. .87 9442. .870 .80 1.0 45.00 200. .75 1500. .85 4500. .87 8543. .870 .80 1.0 50.00 200. .75 1000. .85 4000. .87 7868. .870 .80 1.0 55.00 200. .75 1000. .88 3500. .88 6295. .895 .80 1.0 60.00 200. .75 1000. .88 3000. .90 5620. .918 .80 1.0 85.00 200. .75 1000. .88 2500. .90 5620. .918 .80 1.0 !!!!! FINAL LINE MUST CONTAIN AT LEAST ONE LEFT-JUSTIFIED EXCLAMATION POINT.



Up to five lines of text data and comments can be entered at the top of the file, as long as each line is preceded by an exclamation point (!). Normally only one line is needed consisting of descriptive data and the file name. The very last line in a file must be one or more left-justified exclamation points (this character tells the program when to stop reading data pairs). In the example shown below, lines have been removed to make the file fit into the illustration text box. Note that comments can be added to the right of the second column of data.

Gradient Data File This file contains sets of location (milepost) and gradient data pairs that describe the vertical curves along a given right-of-way. Each gradient value applies to the segment defined by the milepost value on the same line, and the next milepost in the increasing direction (see example below). Gradient is entered in per cent, with a positive grade being an uphill grade when a vehicle is traveling from a lower to a higher milepost. Both mileposts and gradient per cents must be entered as real numbers (numbers with decimal points). Mileposts must be entered in increasing units (from lowest to highest). Error-checking is provided to ensure that all values are increasing.

Up to five lines of text data and comments can be entered at the top of the file, as long as each line is preceded by an exclamation point (!). Normally only one line is needed consisting of descriptive data and the file name. The very last line in a file must be one or more left-justified exclamation points (this character tells the program when to stop reading data pairs). In the example shown below, lines have been removed to make it fit in an illustration text box. Note that comments can be added to the right of the second column of data.

! GRADE FILE FOR CATS SO. CORRIDOR - BOTH DIRECTIONS 0.000 0.000 GR-BOTH.CSC 3.5644 0.000 3.7008 0.000 4.0000 0.820 4.4508 0.900 4.5852 0.000 4.7367 5.820 4.8788 -5.070 . (DATA POINTS REMOVED HERE) . . 22.0695 -1.920 22.2892 -0.250 23.0000 0.000 !!!!

! SM-BOTH.CRC - VPS SPEED FILE, BOTH DIRECTIONS (Revised 1/29/2013) 0.0000 55.0 4.6176 55.0 4.6456 45.0 45 MPH max. between locations 4.6176 and 4.6456 4.8114 55.0 4.8394 45.0 5.7636 55.0 5.7894 45.0 5.9472 55.0 5.9729 45.0 6.3909 55.0 . (DATA POINTS REMOVED HERE) . . 21.9241 35.0 21.4989 65.0 22.0951 25.0 23.0000 25.0 !!!!



Curvature Data File

This file contains sets of location (milepost) and curvature data pairs that describe the horizontal curves along a given right-of-way. These values are used to calculate train resistance due to track curvature. Typically, track spirals are ignored and only the curve radii between adjacent track points of curvature (PC) are used for data input. Each curvature value applies to the segment defined by the milepost value on the same line, and the next milepost in the increasing direction (see example below). Curvature is entered in “degree of curvature” as defined by William Hay, as a dimensionless, positive quantity that is zero for tangent (straight) track. Degree of curvature is approximately 5729.97 divided by the radius of curvature in feet. Both milepost and degree of curvature values must be entered as real numbers (numbers with decimal points). Mileposts must be entered in increasing units (from lowest to highest). Error-checking is provided to ensure that all values are increasing.

Up to five lines of text data and comments can be entered at the top of the file, as long as each line is preceded by an exclamation point (!). Normally only one line is needed consisting of descriptive data and the file name. The very last line in a file must be one or more left-justified exclamation points (this character tells the program when to stop reading data pairs). In the example shown below, lines have been removed to make it fit in an illustration text box. Note that comments can be added to the right of the second column of data.

Positive Contact System Data File This file contains sets of location (milepost) and positive contact conductor numbering data pairs that describe the positive contact system numbering (identification) that will be used by a vehicle as it travels along one route. The positive “track” can be a third (contact) rail or an overhead contact system. Each contact system numbering value applies to the contact segment defined by the milepost value on the same line, and the next milepost in the increasing direction (see example below). Mileposts must be entered as real numbers (numbers with decimal points) and in increasing units (from lowest to highest). Contact system numbering values should be expressed as integers with a maximum value of 99. These contact system numbering values must correspond with their associated contact system conductors contained in the TPLF Power System File; these numbers determine which positive system conductor will supply load current to the vehicle/train for any given location on the ROW. The example below is for a simple LRT system without route branches; systems with branching lines will need to have positive contact data points added at the locations where the vehicles will change from one track to another.

! CATS LYNX Northbound: POSITIVE CONTACT FILE RUP-NB.CSC 0.00 1 OCS for track number 1 23.00 1 No branching to other tracks on this route !!!!

! CTS Track Curvature Data CU-BOTH.CSC 0.0000 0.000 3.5644 0.000 3.8044 0.000 3.8841 0.560 3.9199 0.000 4.0797 0.506 4.1456 0.000 4.4119 0.524 . (DATA POINTS REMOVED HERE) . . 22.0103 0.000 22.0951 16.426 23.0000 0.000 !!!



Negative Contact System Data File

This file is identical to the Positive Contact Data File, except that it describes the negative contact system numbering (identification) that will be used by a vehicle as it travels along one route. The TPLF negative “track” can represent a pair of running rails, a single electrical “equivalent” of multiple paralleled running rails, or a single negative contact rail (for some APM or “fourth rail” systems). Contact system numbering values should be expressed as integers with a maximum value of 99. These contact system numbering values must correspond with their associated contact system conductors in the TPLF Power System File; these numbers determine which negative system conductors will receive vehicle/train load current for any given vehicle location on the ROW. The example below combines northbound and southbound running rails into a single equivalent conductor, track 3 (this simplification can be useful for quick/preliminary studies).

VPS Program Output The three output files created by the VPS program are described below

Run Summary File

The Run Summary File is always created when the VPS program is executed; it contains the station-by-station information viewed on the screen, plus additional information such as energy consumption, maximum current drawn, and a list of all input files used for the simulation (the list of input files is very useful for record keeping). Electrical energy consumption is calculated separately for trains in motion and trains stopped at stations. This enables the propulsion-related energy consumption of the vehicle to be more accurately determined in the traditional English units of kW-hours per car-mile.

Vehicle Electrical Load Profile

The Load Profile is the snapshot-by-snapshot record of vehicle/train performance as it travels along its prescribed route. This file is “read” by the TPLF program and therefore is strictly formatted; it should not be manually edited after it has been created by the VPS if it is to be used with the TPLF (at least, not in a way that modifies the data format). One of these files is required for each type of vehicle/train to be simulated in the load flow simulator, and for each different route. An example of the first 8 seconds of a typical Load Profile using 1 second intervals is shown below.

VPS Load Profile Output File: LP-NB.CSC Created on 1/23/2016 At 11:44:23 !CATS - NB Track 1 Station Location File ST-NB.CTS (to/from Sugar Creek) 1768 Snapshots Follow for a 3 Car Train Real Pos. Neg. Time Train Speed Position Power Track Track Accel. Tractive (sec) ID (mph) (miles) (Watts) No. No. (mphps) Eff.(lbs) 0.0 3S-NB 0.00 3.6421 105000. 1 3 2.778 57327.0 1.0 3S-NB 2.78 3.6425 624536. 1 3 2.777 57327.0 2.0 3S-NB 5.55 3.6436 1131073. 1 3 2.775 57327.0 3.0 3S-NB 8.33 3.6456 1643652. 1 3 2.773 57327.0 4.0 3S-NB 11.10 3.6483 2062997. 1 3 2.771 57327.0 5.0 3S-NB 13.87 3.6517 2301218. 1 3 2.769 57327.0 6.0 3S-NB 16.64 3.6560 2507939. 1 3 2.766 57327.0 7.0 3S-NB 19.40 3.6610 2689941. 1 3 2.763 57327.0 8.0 3S-NB 22.08 3.6667 2757451. 1 3 2.526 52551.0

! CATS LYNX Northbound: NEGATIVE CONTACT FILE RUN-NB.CSC 0.00 3 Return for track numbers 1&2 (Common return) 23.00 3 !!!!



Detailed Output File

This file is a more detailed version of the Load Profile, and it is used primarily for trouble-shooting or calculation verification purposes (If an “N” is included before the filename as shown in the VPS Driver File example, the file will not be produced; if a “Y” is included, it will). Calculation “snapshots” are provided every tenth of a second, so detailed output files can be quite large. An example of the first full second of a typical Detailed Output File is shown below (This section of track is level and tangent, which is why the gradient and curvature forces are zero). The train amps shown are calculated based on the nominal voltage provided in the Vehicle Data File.

VPS Program Dimensional Limits for Data The VPS program currently has the following limits (maximum dimensions) for input and output data; any of these can be increased, if necessary.

Number of station locations (vehicle start/stop points): 100

Number of speed limit data points: 750

Number of gradient data points: 750

Number of curvature data points: 750

Number of positive and negative contact system numbering change points: 500

Number of load profile output data points: 7200

Example Input Data Files The following “example case” VPS data files that were described above are provided on the traction power resources web site. When these files are used with the included VPS_public.EXE program, the user can observe program operation, output, and the effects of varying the parameters. The example VPS case is from a design study for the Charlotte, NC light rail system, and represents the running of 3-car trains along the northbound track for the length of the study area (all double-tracked).

The provided curvature, gradient and speed limit files are the same for both directions of travel (both tracks), which is a common simplification. For detailed design studies, separate track alignment data is typically used for each track, provided it is available.

All input data files for a study case/scenario should be copied to a single directory (folder); program output will be written to the same directory. Additional VPA data files for southbound running are also included for reference, these will also be needed to simulate train operation in both directions for Traction Power Load Flow usage.

VPS Detailed Output File: DET-NB.CSC Created on 1/23/2016 At 11:44:23 Mile- Speed Tractive Effi- Per Rolling Aero Curve Grade Time Post Speed Limit Accel. Effort ciency Cent Friction Drag Force Force Train (sec.) (mi.) (mph) (mph) (mphps) (lbs.) Grade (lbs.) (lbs.) (lbs.) (lbs.) Amps ------ -------- ------ ------ ------- -------- ------- ------ -------- ------ ------ ------ ------ 0.0 3.6421 0.00 55.00 2.778 57327.0 0.60 0.00 783.5 0.0 0. 0. 140. 0.1 3.6421 0.28 55.00 2.778 57327.0 0.60 0.00 786.0 0.0 0. 0. 140. 0.2 3.6421 0.56 55.00 2.778 57327.0 0.60 0.00 788.5 0.1 0. 0. 140. 0.3 3.6421 0.83 55.00 2.778 57327.0 0.60 0.00 791.0 0.2 0. 0. 140. 0.4 3.6422 1.11 55.00 2.778 57327.0 0.60 0.00 793.5 0.4 0. 0. 140. 0.5 3.6422 1.39 55.00 2.777 57327.0 0.60 0.00 796.0 0.7 0. 0. 140. 0.6 3.6422 1.67 55.00 2.777 57327.0 0.61 0.00 798.5 0.9 0. 0. 140. 0.7 3.6423 1.94 55.00 2.777 57327.0 0.61 0.00 801.1 1.3 0. 0. 140. 0.8 3.6423 2.22 55.00 2.777 57327.0 0.61 0.00 803.6 1.7 0. 0. 140. 0.9 3.6424 2.50 55.00 2.777 57327.0 0.61 0.00 806.1 2.1 0. 0. 140. 1.0 3.6425 2.78 55.00 2.777 57327.0 0.61 0.00 808.6 2.6 0. 0. 833.



Name of Input Data File Data File Type (Northbound Travel) VPS-NB.CSC VPS Driver File ST-NB.CSC Stations File 3-CAR-DATA.CSC Train Data File SM-BOTH.CRC Speeds File (for both travel directions) GR-BOTH.CSC Gradient File (for both directions) CU-BOTH.CSC Curvature File (for both directions) RUP-NB.CSC Positive Contact/Routing File RUN-NB.CSC Negative Contact/Routing File

VPS Application Notes

File Names and File Storage

The VPS program runs in a Microsoft “window”, but file manipulations are still performed using a text editor (WordPad or NotePad, typically) or using Excel-to-text conversions. To simplify usage, it is helpful to have a standard file naming and storage convention. The author has found it helpful to start all VPS input file types with the letters highlighted in bold font in the table above (or something similar…the importance is consistency). Using the same .XXX filename extension for all cases for each client/study is also helpful (HRT for the Norfolk LRT, CTA for Chicago Transit Authority, etc.). Wordpad can recognize these file associations and automatically open them when they are double-clicked.

It is recommended that Windows Explorer folders be used to organize the various files. All VPS files for a particular study can be stored under a ‘VPS” folder, with various subfolders used to segregate different study cases (1-car trains, 2-car trains, different assumptions/scenarios, etc.). The VPS_public.EXE program must reside in the same folder as the data input files, and the program output will be written to the same folder in which it is located.

Creating Input Files Using Excel

Input data for VPS simulation is rarely in the format required for direct input. Information can be taken directly from design drawings, entered into Excel workbooks, and manipulated as required to obtain the units and formats required for the VPS program. Some Excel workbook application examples for the VPS program are included on the traction power resources web site.

The data columns needed for the VPS program input files can be saved as “formatted text (space delimited)” type files, file extension .PRN. A text editor can then be used to get them from PRN format into the final format for VPS usage, if needed (the author typically uses WordPad for this).

Creating Output Graphs Using Excel

The current version of the VPS program does not provide automatic plotting of output data. However, the data columns from the load profiles or detailed output files can easily be imported into Excel for plotting, if desired. A more automated method of doing this is envisioned in the future.

ETSA INSTRUCTION MANUAL TPLF PROGRAM


III. Traction Power Load Flow Program (TPLF) [UNDER CONSTRUCTION]

This section describes the application of the Traction Power Load Flow program (TPLF). The TPLF program simulates the second-by-second power system performance of transit systems powered by direct current, such as light rail, heavy rail rapid transit, automated people mover (APM) and electric trolleybus.

The Traction Power Load Flow performs a time-based simulation of a traction power system. This involves the selection by the user of a time period over which the simulation will occur, and the scheduling of the desired vehicle or train dispatches during this period. These dispatches are scheduled by a timetable in an input data file. During the simulation time period, the Traction Power Load Flow moves scheduled trains along their respective routes according to the train movement simulation information contained in the appropriate power profiles. At regular, user-selected time intervals (typically, every second), new positive and negative network nodes are created for each vehicle or train at their proper location on the power system, the initial electrical load or regenerated currents are determined from the power profiles, and a network solution ("snapshot") is performed. Depending on whether a voltage-dependent train model is selected by the user or if the train is regenerating current into the system, further network solutions may be performed to arrive at a solution based on an adjusted vehicle or train load. Results from each "snapshot" are written to up to eight different output data files for review and further processing using either commercial spreadsheet/presentation graphics programs or TPLF support programs. Information derived from each snapshot is also stored and managed internally to produce a comprehensive summary report file at the end of the simulation.

Program input is currently performed via a combination of free-format "text" (ASCII) data files, similar to the VPS program input files. These files describe the electrical network, the locations where current flow calculations are desired, and the vehicle scheduling desired. All input files are typically prepared using spreadsheets and a text editor such as “WordPad”, with the exception of the vehicle load profiles. Load profiles, which are data files of vehicle power consumption versus time, are prepared by the Vehicle Power Simulator.

Program output is also currently in text file format to simplify further formatting and analysis using standard word processing, spreadsheet, and ETSA "post-processing" software.

Current Operating Systems Supported TPLF_93.EXE is currently a Windows application program that will run under Windows XP or later windows operating systems. It can be run from inside the Windows Explorer program by double-clicking on the highlighted program name. This method is recommended since it allows input data to be viewed and edited simultaneously inside "tiled" windows.

Technical Basis and Underlying Assumptions The TPLF program uses the nodal equation method to solve the electrical network representing the traction power system. In other words, it simultaneously solves both "halves" of the direct current traction power system; from the cathode of the rectifier to the vehicle (the positive supply network), and from the vehicle back to the rectifier anode (the negative return network). These two networks are represented in the TPLF by an assembly of "branches" and "nodes" that are used to model individual or combined pieces of equipment. A branch is any conductor (wire, cable, bus bar, third rail, running rail, etc.) that can be modeled as a linear resistance. A node is simply an end point of a branch, or a junction point for multiple branches. Parallel conductors can be explicitly modeled as separate branches, if desired, or combined into equivalent conductors. Rectifiers are modeled as branches with a variable resistance that increases with high forward load current in a manner specified by the user. The alternating current (ac) side of the rectifiers is modeled as a Thevenin equivalent of the connected ac power source (typically, an electric utility feeder). Any conceivable configuration of electrical equipment can be efficiently simulated to almost any desired degree of detail.



The solution method employed for the nodal equation analysis is a direct-solving lower upper (LU) decomposition procedure that utilizes sparse matrix techniques. Sparse matrix solvers take advantage of the fact that typical power systems matrices are "sparse", that is, they are filled almost entirely with zeros. Sparse matrix solvers only store and operate on the matrix non-zeros, greatly improving solution speed and accuracy.

The program currently has the following limits (maximum dimensions) for input data, which can be increased if needed:

Number of nodes: 950

Number of branches: 1500

Number of branch ammeters: 600

Number of vehicles on the system: 350

Number of vehicle load profiles: 39

TPLF Program Input Requirements TPLF requires five "space delimited" input text files in order to operate. These files must reside in the same directory with the TPLF.EXE program, otherwise they will not be found by the program:

TPLF Driver File

Power System File

Ammeter Location File

Vehicle Dispatch File

Clock File

Each of these input files is described below.

TPLF Driver File

This “file of filenames” contains a listing of the names of all TPLF input and output files. The maximum length of each filename is 20 characters (15 for load profile filenames), and the filenames must be listed left-justified and in the proper order. The filenames can include any legitimate characters, and similar file extensions can be used for ordering project data. An example is shown in the box on the next page.

The user has the ability to prevent the Voltage, Snapshot, Substation Power, Rectifier Current and Node Voltage Output files from being created, if desired. This is achieved by placing an “N” at the beginning of the line for the associated filename (a “Y” will result in the file being created). A space must be inserted between the letter and the associated file name.

When the TPLF program starts, it will request the name of this driver file. The User enters the driver file name, followed by the “enter” key. The program will read the information in this file, and proceed without any further User input unless data files errors are detected.



Power System File (“System File”)

This file contains all the information about the transit system electrical network. All data in this file should be separated by spaces unless otherwise indicated (Tabs should never be used; they will cause program errors). The file has five different data "sections", each with their own format. The data that belongs in each of these sections is illustrated in Exhibit 1 below, which is an actual system file with enough lines removed from all five data sections to be shown on a single page. Note that the line numbers have been added to Exhibit 1 for illustrative purposes only; the actual datafile does not have line numbers. The data fields for each section are also described below.

Before a power system file is created, a schematic diagram of the entire electrical network should ALWAYS be created. The schematic diagram should be labeled with branch names, node names, track numbers, conductor types, ammeter locations, etc. It is recommended that a separate version of the schematic diagram be created for each system modification scenario that will be simulated. This is needed for proper record-keeping as well as input data debugging/checking. For checking a newly-created network, highlighting the node and branch information on a hard copy of the schematic diagram is a good practice.

System File General Requirements Node names must not exceed 8 characters in length.

Branch names must not exceed 8 characters in length.

REAL numbered input must include decimal points.

INTEGER numbered input should have no decimal points.

CHARACTER (CHAR) input can be any combination of letters and numbers.

The file is “free format” style, with data items separated (“delimited”) by spaces. For character data such as node names and branches, it is wise to provide the full eight characters between data columns, even if less than eight characters are being used for the names.

The end of the substation, rectifier, node and branch data sections must be identified by placing an exclamation point at the beginning of the next line (see example).

All resistance data is entered in units of Ohms.

User notes can be added after the data on each line, as shown in the example below. This can be very helpful for keeping track of file updates and configuration changes.

SY-BASE.HRT System File TPLF DRIVER FILE "LF-BASE-2.HRT" AM-BASE.HRT Ammeter Location File DI-BASE2.HRT Vehicle Dispatch File CL-75MIN.HRT Simulation Clock File SM-BASE2.HRT Summary Output File Y VO-BASE2.HRT Voltage Output File (requested) Y SO-BASE2.HRT Snapshot Output File (requested) N SP-BASE2.HRT Substation Power Output File (not requested) N RC-BASE2.HRT Rectifier Current File (not requested) N AO-BASE2.HRT Ammeter Output File (not requested) N NV-BASE2.HRT Node Voltage File (not requested) LP-EB-2.HRT Voltage Profile (Eastbound 2-car train) LP-WB-2.HRT Voltage Profile (Westbound 2-car train)



“Header” Data

The first four lines of data are utilized for descriptive purposes. The program will read the first 80 characters in each of these four lines, and echo them into the header of the Summary Output File. The fifth line contains two real-numbered variables, each of which should be separated by at least one space. These variables are described in the table below.

Variable & Column Number

Variable Description – Header Data Line # 5 Data Type

1 Nominal voltage used to convert vehicle load kW to Amperes. REAL 2 Maximum allowable voltage rise at train due to regenerative braking (Volts). REAL

EXHIBIT 1 - PORTIONS OF A TPLF SYSTEM FILE 1. TPLF PROGRAM SYSTEM FILE SY-BASE.HRT (NORFOLK BASE MODEL) 2. Per Prelim. Design: Parallel Feeders, 1.0 MW TPSS 3. 4.5% Regulation, 820 V Light Load 4. All Equipment in Service 5. 785.00 900.0 !System nominal and maximum voltages 6. TPSS-6 NEG-6 DVP-6 AC-6 34500. 5.95130 0.0 000.00 1 x 1.0 MW 7. TPSS-5 NEG-5 DVP-5 AC-5 34500. 5.95130 0.0 000.00 1 x 1.0 MW 8. TPSS-4 NEG-4 DVP-4 AC-4 34500. 5.95130 0.0 000.00 1 x 1.0 MW 9. TPSS-3 NEG-3 DVP-3 AC-3 34500. 5.95130 0.0 000.00 1 x 1.0 MW 10. TPSS-2 NEG-2 DVP-2 AC-2 34500. 5.95130 0.0 000.00 1 x 1.0 MW 11. TPSS-1 NEG-1 DVP-1 AC-1 34500. 5.95130 0.0 000.00 1 x 1.0 MW 12. ! 13. AC-6 DC-6 0.02772 0.02272 0.02911 0.03049 1274. 785. 34500. 607.18 34500. 1.3505 IN 820 VLL 14. AC-5 DC-5 0.02772 0.02272 0.02911 0.03049 1274. 785. 34500. 607.18 34500. 1.3505 IN 820 VLL 15. AC-4 DC-4 0.02772 0.02272 0.02911 0.03049 1274. 785. 34500. 607.18 34500. 1.3505 IN 820 VLL 16. AC-3 DC-3 0.02772 0.02272 0.02911 0.03049 1274. 785. 34500. 607.18 34500. 1.3505 IN 820 VLL 17. AC-2 DC-2 0.02772 0.02272 0.02911 0.03049 1274. 785. 34500. 607.18 34500. 1.3505 IN 820 VLL 18. AC-1 DC-1 0.02772 0.02272 0.02911 0.03049 1274. 785. 34500. 607.18 34500. 1.3505 IN 820 VLL 19. ! Data section delimiter character 20. PN2-1 1.934 Positive network node names and node mileposts 21. PN2-2 1.980 22. PN2-2A 1.998 23. PN2-SW1 2.498 24. PN2-3 2.695 25. PN2-4 2.695 26. F6-TAP 0.000 27. NN-1 1.9340 Negative network node names and node mileposts 28. NN-2 1.9800 29. NN-3 2.3400 30. NN-4 2.6950 31. ! 32. PB2-1 PN2-1 PN2-2 P 2 0.00405 C PS-1 Positive branches, track #2 33. PB2-2 PN2-2 PN2-2A P 2 0.00153 C PS-1 34. PB2-3 PN2-2A PN2-SW1 P 2 0.04351 C PS-2 35. PB1-1 PN1-1 PN1-2A P 1 0.00092 C PS-2 Positive branches, track #1 36. PB1-3 PN1-2A PN1-SW1 P 1 0.02618 C PS-2 37. PB1-5 PN1-6 PN1-7 P 1 0.09888 C PS-4 38. J1-1 PN1-2A PN2-2A P 0 0.00026 C '' “Jumper” connections (no track #) 39. J2-1 PN1-3 PN2-3 P 0 0.00026 C '' 40. F6-W DC-6 F6-TAP P 0 0.00129 C '' Pos. feeder cables (no track #) 41. F5-W DC-5 PN2-9 P 0 0.00129 C '' 42. NB2-1 NN-1 NN-2 N 2 0.00113 C '' Neg. feeder cables (no track #) 43. NB2-2 NN-2 NN-3 N 2 0.00888 C '' 44. NB2-3 NN-3 NN-4 N 2 0.00876 C '' 45. NB2-4 NN-4 NN-5 N 2 0.01123 C '' 46. G-1 NN-1 GROUND G 0 1646.904 C '' Rail-to-earth grounding branches 47. G-2 NN-2 GROUND G 0 98.9 C '' 48. G-3 NN-3 GROUND G 0 52.977 C '' 49. G-4 NN-4 GROUND G 0 46.764 C '' 50. ! LAST LINE IN THE FILE MUST BEGIN WITH AN EXCLAMATION POINT!!



Substation Ac Source Data

Substation Ac Source Data consists of 8 fields (columns) which describe the "Thevenized" substation equivalent as modeled by TPLF, hereafter referred to as an "ac source model". These fields are shown in Exhibit 1 in lines 6 through 11. A substation may have more than one ac source model. The number of ac source models can equal the number of independent ac feeders connected to the substation; however, unless there is a need to explicitly model individual rectifiers, a single ac source model per substation is normally satisfactory. Each ac source model has a source node, an ac bus node, a dc bus node, and a “negative” node. Each ac source model represents one or more transformer/converter units, including ac system source impedance. The source, ac bus, and negative node variables are described in the table below (the dc bus node information is entered later, with the Substation Rectifier Data).


Variable Description – Substation Ac Source Data

Data Type

1 Branch name of substation equivalent " ac source". This branch, called the "ac source branch", is assigned the magnitude of the equivalent source impedance as "seen" by the substation (Ohms).

CHAR

2 Name of the negative node associated with this source. Each source must have a negative node. The negative nodes for the ac sources are automatically connected to the network reference node through an essentially infinite resistance.

CHAR

3 Node name for the "utility" end of the source branch. CHAR 4 Node name for the traction substation end of the source branch. CHAR 5 Voltage of the ac source, expressed in Volts. REAL 6 Magnitude of the source impedance, expressed in Ohms at source voltage. REAL 7 No-load losses of the converter transformer, expressed in Watts (if known). REAL 8 Full (100%) load losses of the converter transformer, expressed in Watts. REAL

The remainder of the line after the last (eighth) field is not "read" by the program, and it can be used for notes.

Substation Ac Source Data must be separated from Substation Rectifier Data by a line with an exclamation point as the first character of the line (the rest of the line will be ignored).

Substation Rectifier Data

Substation Rectifier Data consists of 14 fields that describe the ac-to-dc conversion parameters including the converter-transformer unit characteristics. These parameters, shown in Exhibit 1 as lines 13 through 18, are described in the table below.


Variable Description – Substation Rectifier Data

Data Type

1 Node name for the traction substation end of the source branch, which must match the name used in the Substation Ac Source Data.

CHAR

2 Node name for dc side of the rectifier. CHAR 3 Rectifier equivalent resistance between 0 to 100% of full load current. Typically this

is the (change in voltage) / (change in current) at the rectifier dc output. This can be a negative number to reflect output voltage rise with increasing load current, a theoretical possibility (but not practical) for thyristor rectifiers, but it must be non-zero. This value can represent a single rectifier, or multiple rectifiers in parallel.

REAL

4 Rectifier equivalent resistance between 100% and 200% of rectifier full load current (R = ΔV / ΔI from the rectifier current-voltage characteristic)

REAL




REAL


REAL

7 Rated (nameplate) dc output current at 100% load (Amperes). REAL 8 Rated (nameplate) dc output voltage at 100% load (Volts) REAL 9 Nominal nameplate voltage of rectifier transformer primary (Volts). REAL

10 Nominal nameplate voltage of rectifier transformer secondary (Volts). REAL 11 Rectifier transformer tap setting for primary side no load taps (Volts). For the more

rare case of low side taps, let variable 7 represent the low side tap setting and this variable represent the nominal voltage on the high side of the rectifier transformer.

REAL

12 The ac-to-dc voltage conversion ratio at light load. This is a theoretical ratio that is dependent on the configuration of the rectifier/converter circuit. For 6 and 12-pulse two-way (bridge) type rectifiers, use 1.3505.

REAL

13 Rectifier on/off 3-character variable "switch". If "OUT" is inserted in this field, the rectifier will be considered out of service (open), and this status will be reflected in the program output. Any other characters inserted in this field will have no effect. It is recommended that "IN," be normally inserted in this field as a placeholder.

CHAR

14 Coincident demand calculation 3-character variable inclusion/exclusion "switch". If "OUT" is inserted in this field, the rectifier will not be included in 15 and 30 minute coincident demand calculations. Any other characters inserted in this field will have no effect. ' ' can be inserted in this field as a placeholder, although this is not shown on the example above to minimize page width.

CHAR

The number of rows of Substation Rectifier Data should be equal to and in the same order as the rows of the Substation Ac Source Data (ideally all this information should be input in a single line of data, but that is not practical, so it has been divided into two separate lines, and the program links them together).

The remainder of the line after the last (11th) field is not "read" by the program, and it can be used for notes.

Substation Rectifier Data must be separated from the Dc Distribution Node Data by a line with an exclamation point as the first character (the rest of the line will be ignored).

Dc Distribution System Node Data

Dc Distribution System Node Data consists of 2 fields that describe the electrical node names, and their location (milepost) with respect to the right-of-way. These 2 parameters, shown in Exhibit 1 as lines 20 through 30, are described below.


Variable Description – Dc Distribution System Node Data

Data Type

1 Node name for all non-substation network nodes (none of the names for the nodes in Substation Ac Souce Data and Rectifier Data groups can appear in this list). All node names must be unique. The node name “GROUND” is reserved and cannot be used in this data section (it can only be used in the System Branch Data section).

CHAR

2 Milepost associated with this node (Miles). Mileposts are only required for nodes which represent "tracks" on which a vehicle will be operating and consuming or regenerating current. Milesposts can be any real number including positive, negative, and zero. Nodes representing "tracks" must have accurate mileposts so that (temporary) branches created by vehicle movements will be of appropriate length.

REAL

The remainder of the line after the last (2nd) field is not "read" by the program, and can be used for notes.



Dc Distribution System Node Data must be separated from the Dc Distribution Branch Data by a line with an exclamation point as the first character (the rest of the line will be ignored).

Dc Distribution System Branch Data

Dc Distribution System Node Data consists of 8 fields that describe the electrical branches. Branches are used to electrically describe any type of conductor or load that can be represented as a linear resistance. For example, a fixed dc load at any location on the dc system can be represented as a branch between a positive node and a negative node. In addition, the distributed track-to-earth resistance can be represented by suitably-located “grounding branches” connected between running rail nodes and the “ground” node.

These 8 parameters, illustrated in Exhibit 1 as lines 32 through 49, are described in the table below.


Variable Description – Dc Distribution Branch Data

Data Type

1 Branch name, consisting of any combination of ASCII characters (up to 8). CHAR 2 The "from" node name. CHAR 3 The "to" node name. Note that branch current calculations assume direction of

positive current flow is from the "from" node to the "to" node. As shown in Lines 46-49 of Exhibit 1, the “GROUND” node can be used as a “to” node for grounding branches. The “GROUND” node is remote earth (zero voltage reference).

CHAR

4 Network classifaction identifier, single character, used for allocation of electrical losses. Enter "P" if branch is in positive network, "N" for negative network, “G” for a rail-to-earth resistance, or "L" for a lumped load (a lumped load is modeled as a resistor between a positive node and a negative node). At least one space should separate this character from data in field #3.

CHAR

5 Branch number, which can be any integer value. "Tracks" are electrical branches from which vehicles receive and return power, such as contact wires or contact rails for the positive network, and running rails or negative contact rails for the negative return network. Branches which do not represent "tracks", such as feeder and supplementary conductors, should be assigned a zero branch number. Branch numbers on which trains are running should match the associated track numbers in the load profiles for both the positive and negative return network conductors. Note that running rails (and associated parallel conductors, if desired) can be treated as one equivalent conductor, if desired, with a single (common) track number. This may be appropriate if the running rails are large and are frequently cross-bonded (great savings in network size can be obtained by modeling the negative return system this way).

integer

6 Branch resistance, in ohms. REAL 7 Branch trip/close identifier, single character. This character should be located no

more than 3 spaces to the right of the branch resistance field. If a "T" is inserted in this field, the branch will be treated as if open (not in service), and the program results and output will reflect this. Any other character in this field will be ignored. It is recommended that a "C" be left in this field as a placeholder.

CHAR

8 Power section identifier of up to 6 characters. Used only if power sections are desired in program voltage results. If power sections are not used, this field can be used for notes; otherwise ' ' should be inserted in this field to ensure the program does not skip to the next line of data when attempting to find the power section identifier.

CHAR

The last line of Dc Distribution System Branch Data must be followed by a line with an exclamation point as the first character (the rest of the line will be ignored).



System File Input Error Checking

TPLF performs a number of tests on the System File data before simulation of operational "snapshots" begins. Errors detected in the system file are written to the screen, and to the Summary Output File. Normally, when errors are detected, a message is written to the screen indicating this has occurred. If the program does not appear to be running correctly, stop program execution and review the contents of the Summary Output File.

Tests are performed to trap the following "fatal" errors:

Nodes with no connected branches;

Converter and branch resistances with zero values;

Non-unique node names; and

Branch "to" or "from" nodes not found in Dc Distribution System Node Data or Substation Rectifier Data.

The TPLF program is a very general electrical network simulator, permitting the User to create very complex electrical networks with many interconnections and electrical loads. Inadvertent interconnections cannot be detected by the program; therefore it is up to the User to carefully compare the System File and program results with the simulation network schematic diagram and train schedules to confirm that program results reflect the intended conditions. Unexpected voltages or current flows should be investigated. System File Data Preparation

The Dc Distribution System Node Data and Dc Distribution System Branch Data are best prepared by utilizing a spreadsheet to calculate distances and equivalent branch resistances. Examples of Excel workbooks used for this purpose are included. The resistances of various conductor types are stored in a "lookup table" that is referenced by the branch resistance calculations. The sheets that calculate branch resistance also use lookup functions to bring node milepost data into the spreadsheet, and to check that the "from" and "to" node names are all included in the Dc Distribution System Node Data. This provides node name checking in addition to branch resistance calculation.

After all dc distribution system node and branch data has been prepared, the "working" sheet rows and columns are "hidden", and the various sheets are then "saved as" Excel type PRN (space-delimited text) files. Once in PRN file format, the data can be cut and pasted into a new or into an existing System File.

Ammeter Location File

The Ammeter Location File specifies the locations at which current flow calculations are to be performed. These locations are referred to as "ammeters". An ammeter can be specified for any branch that is included in the Dc Distribution System Branch Data. If the branch is a "track", then the Branch Number must also be specified as well as the desired ammeter location (milepost).

The Ammeter Location File contains four columns of data. A portion of a typical Ammeter Location File is shown below in Exhibit 2. Note that the line numbers have been added to Exhibit 2 for illustrative purposes only; the actual datafile does not have line numbers.



The data fields for each column are described in the table below. Note that the first line is “reserved”; it contains data field width markers that are a holdover from the days of Fortran-formatted input data files. These are no longer absolutely necessary, but helpful enough to remain in the program.


Variable Description for Ammeter Location File

Data Type

1 Ammeter memo text string, up to 15 characters long. The 15 character string must be enclosed in single quotes.

CHAR

2 Branch name of branch to be metered. This must match the branch name of the corresponding branch in the System File, or else program execution will stop and an error message will be generated.

CHAR

3 Branch number of the branch to be metered. This must match the branch name of the corresponding branch in the System File. A number is only needed if this branch is a "track" branch (OCS, contact rail, running rail, etc.)

integer

4 Milepost location of ammeter (in miles). This is used when an ammeter is inserted into a “track” segment, such as a section of contact rail or OCS (in this case, the program needs to know the ammeter milepost location). NOTE: An ammeter cannot be located exactly on a node (this will cause a "divide by zero" program error). For OCS or contact rail "track" ammeters, a good location is 0.001 mile on either side of a feeder tap node (the “hottest” location of a section of OCS is typically the segment where the OCS meets the supply feeder)

REAL

Ammeter File Input Error Checking

TPLF performs a number of tests on the Ammeter Location File data before simulation of operational "snapshots" begins. Errors detected in the system file are written to the screen, and to the Summary Output File. Normally, when errors are detected, a message is written to the screen indicating this has occurred. In the case when the program does not appear to be running, stop the program and review the contents of the Summary Output File.

Tests are performed to trap the following "fatal" errors:

Number of ammeters exceeds program maximum limits (dimensions);

Ammeter branch name does not match any of the System File branch names;

Ammeter branch number is not in agreement with System File data; and

Ammeter milepost is not in agreement with System File data.

EXHIBIT 2 - PORTION OF TPLF AMMETER LOCATION FILE

1. *************** ****** * ****** TPLF AMMETER FILE: AM-BASE.HRT 2. 'POS. FDR. F6-W ' F6-W 0 0.000 Positive feeder cable 3. 'POS. FDR. F5-E ' F5-E 0 0.000 4. 'POS. FDR. F2-W ' F2-W 0 0.000 5. 'POS. FDR. F1-E ' F1-E 0 0.000 6. 'TPSS #3 RETURN ' RET-3 0 0.000 Negative return cable 7. 'TPSS #2 RETURN ' RET-2 0 0.000 8. 'TPSS #1 RETURN ' RET-1 0 0.000 9. 'CAT PB2-3 ' PB2-3 2 2.000 Ammeters located in catenary 10. 'CAT PB1-3 ' PB1-3 1 2.000 11. 'SWFT PB2-3A ' PB2-3A 2 2.690 12. 'SWFT PB1-3A ' PB1-3A 1 2.690 13. 'CAT PB2-4A ' PB2-4A 2 4.400 14. 'CAT PB1-4A ' PB1-4A 1 4.400 15. 'CAT PB2-5 ' PB2-5 2 4.410 16. 'CAT PB1-8 ' PB1-8 1 9.297 LAST LINE ENDS WITH CR



Vehicle Dispatch File

This file contains the information that enables the TPLF program to start the selected trains or vehicles at their desired location and dispatch (schedule) time. This includes the train identifier (“ID”), the starting time, and the track on which the train starts. The train ID can be up to 6 characters long, and must match the ID that is used in the corresponding Load Profile. At present, if an incorrect starting track is used, the program will not trap this error; the train will just be ignored by the program. This error will be trapped in future program updates.

The data fields for each column after the first line are described in the table below. The first line is reserved for Dispatch File memo text. The program will read the first 80 characters from this line, and echo them into the header of the Summary Output File (for record-keeping purposes).


Variable Description for Vehicle Dispatch File

Data Type

1 The time that the indicated train should start on the indicated track - hours integer 2 The time that the indicated train should start on the indicated track - minutes integer 3 The time that the indicated train should start on the indicated track - seconds integer 4 Train identifier from Load Profile (up to 6 characters) CHAR 5 Track number on which train is starting (must match Load Profile) integer 6 Auxiliary kW for one car (needed for forced reduced perf. calculations only) REAL 7 Number of cars in the train (needed for FRP calculations only) REAL

When the TFLP program is started, the Dispatch File train ID information will first be compared with the vehicle information found in the Load Profiles that are listed in the TPLF Driver File (file-of-filenames). If the train ID is not found in the Load Profiles, program execution will stop.

The following application points related to the Dispatch file are important.

To obtain correct results, the entire rail system needs to be completely “populated” with vehicles for the simulation period defined in the Clock File. In other words, trains must be on the tracks at the desired headways throughout the system when the simulation “clock” starts. This requires the User to consult the Load Profiles to determine how long it takes the various vehicles to travel the length of

EXHIBIT 3 - TPLF VEHICLE DISPATCH FILE

HRT BASE CASE: 2-CAR TRAINS @7.5 MIN. HEADWAYS 7 16 38 2CEB 2 30.0 2 7 24 08 2CEB 2 30.0 2 7 31 38 2CEB 2 30.0 2 7 39 08 2CEB 2 30.0 2 7 46 38 2CEB 2 30.0 2 7 54 08 2CEB 2 30.0 2 Sim. Start @ PLUME 8 01 38 2CEB 2 30.0 2 8 09 08 2CEB 2 30.0 2 8 16 38 2CEB 2 30.0 2 8 24 08 2CEB 2 30.0 2 7 14 15 2CWB 1 30.0 2 BEGIN WESTBOUND TRAINS 7 21 45 2CWB 1 30.0 2 7 29 15 2CWB 1 30.0 2 7 36 45 2CWB 1 30.0 2 7 44 15 2CWB 1 30.0 2 Sim. Start @ PLUME 7 51 45 2CWB 1 30.0 2 7 59 15 2CWB 1 30.0 2 8 06 45 2CWB 1 30.0 2 8 14 15 2CWB 1 30.0 2 8 21 45 2CWB 1 30.0 2 LAST LINE SHOULD BE BLANK (CARRIAGE RETURN ONLY)



the system. With this information, the User can schedule trains to start early enough so that the system is already “full” of trains when the simulation clock starts.

The worst case for low voltage in most traction power systems is typically caused by trains starting simultaneously near the midpoint between two substations during rush hour. At present, this scenario must be modeled by manually calculating the required dispatch times for a simultaneous start with Excel spreadsheets using the travel times contained in the Load Profiles. Since vehicles travel through the system in strict accordance with their associated Load Profiles, it is straightforward enough to determine where they will be at any given time. The same approach is used to ensure that trains are suitably spaced (and do not “collide”) at branching points. Typical Excel sheets that assist with these applications are included.

Since transit system rarely operate precisely on time, it is wise to simulate at least a few “offsets” in time between inbound and outbound vehicle dispatch times, unless simultaneous starts are being modeled (simultaneous starts are typically the “worst case” type of operational perturbation). These “offsets” are normally needed to capture the worst case combination of inbound and outbound traffic. In the future, means to perform offset scenarios automatically will be investigated.

Clock File

This file contains the desired start and end times for the simulation, and the time interval (”snapshot”) to be used for the simulation. The format of the start and end times are hours, minutes and seconds, all of which are integers, separated by spaces. The simulation time interval must be expressed in seconds, and in the format of an integer equal to or larger than one. An example is provided below.

The TPLF program normally runs very quickly, and it is therefore recommended that 1 second snapshot intervals always be used to maximize accuracy.

For the Norfolk LRT example, all trains in both directions operate at 7.5 minute headways during rush hour. As long as the system is completely “populated” with trains during the 8:00:00 to 8:07:30 simulation “window”, a 7.5 minute simulation length is sufficient to capture all necessary information, since the simulation results will repeat themselves exactly every 7.5 minutes (the student can prove this for themselves as an exercise). In fact, it can be argued that, to obtain theoretically correct root-mean- square (rms) currents, the duration of the system simulation should match the headway (the headway is effectively the time “period” of signal repetition that is required by an rms calculation).

Load Profiles These files contain the power consumption of a single train as it travels from one location to another. These files are created by the Vehicle Power Simulator program. One of these files is needed for each train route used in the TPLF simulation. These files must reside in the same directory as the TPLF program and TPLF input files for a given simulation case. The names of these files must be included in the TPLF driver file for them to be found and utilized. TPLF Program Output The Traction Power Load Flow can produce a total of eight different output files for each simulation, depending on the information needs of the user. These are the Summary, Train Voltage, Snapshot, Substation Power, Rectifier Current, Ammeter Output, Node Voltage List and Node Voltage Column files. The Summary Output file is always created at the end of each simulation while the remaining six are created at the discretion of the user, avoiding the production of unnecessary paper and disc space when

EXHIBIT 4 - TPLF CLOCK FILE 7.5 Minute Peak Service Simulation TPLF FILE: CL-75MIN.HRT 8 00 00 START TIME 8 07 30 END TIME 1 SNAPSHOT INTERVAL (SEC.)



the simulation results for a long time period are desired. Each file is stamped with its file name and date of creation to simplify identification and record keeping. All output files, with the exception of the Summary, Snapshot, and Node Voltage List are created in "delimited" format to enable them to be imported into common spreadsheet, database and presentation graphics programs. Examples of these files are included.

Summary Output File This contains highlights of a particular traction power system simulation and confirms important input parameters, including: location of the lowest calculated train voltages as well as the instant of time (snapshot) at which they occurred; descriptive text from the headers of various input files; instantaneous peak and time-varying ac and dc current flows and energy losses; substation peak and average power flows, and substation energy consumption. If regeneration of power from vehicles into the traction power system is detected during a simulation, information on regenerated energy and system receptivity to regeneration is reported. Coincident and noncoincident system peak power demand is also reported for 15 and 30 minute demand intervals only if the simulation time exceeds the respective interval.

Train Voltage Output File This file contains an uninterrupted listing of all calculated train voltages and associated train location and power section resulting from a simulation. The listing is ordered according to the instant (snapshot) at which the train voltages were calculated, according to the simulator "clock". This file is used primarily as input to the ETSA program module “VOLTPRO” which creates profiles of minimum train voltage versus position, and rail voltage versus position, for individual trains as they move through the power system. The voltage profiles from VOLTPRO are stored in a text file format suitable for plotting by means of spreadsheet or presentation graphics programs.

Snapshot Output File This contains detailed information on train voltages and current draw, ac and dc power system voltages, current flows, power consumption and losses for each time interval (snapshot) calculated during a simulation.

Substation Power Consumption Output File This file contains a column of calculated substation ac power consumption versus snapshot time for each traction power substation, plus a column which sums all substation loads for each snapshot. At the bottom of the file, coincident system and noncoincident system and substation peak power demands are calculated for 15 and 30 minute demand intervals.

Rectifier Current Output File This contains a column of simulated rectifier current flow versus time for each snapshot in a given simulation. The data is used primarily for plotting purposes and for rectifier loading analysis. The column headings are the rectifier cathode node names associated with the rectifier currents being calculated.

Ammeter Output File This file contains columns of simulated conductor currents versus time for each metering point requested by the user. This information is used for plotting individual conductor currents and for conductor transient temperature analysis, which is performed by the separate post-processor type program module "WIRETEMP". The column headings are the branch names and the milepost locations associated with each metering location.

Node Voltage List File This sequentially lists the calculated voltage at every electrical node in the electrical network, for every simulation "snapshot". This information is extremely helpful in finding the causes and magnitudes of voltage drops anywhere in the traction power distribution network, as well as track-to-earth voltages. This file can be quite long.



Node Voltage Column File This file provides the same information as the Node Voltage List File, but in column format. This format is more suitable for plotting purposes

TPLF Program Operation The program in its current state is designed to be executed from within a Windows Explorer folder, by double-clicking on the file name. Windows Explorer enables the simultaneous viewing and editing of the TPLF input files via use of the Microsoft WordPad editor (a simple text editor included with Windows). If all the file extensions for a given simulation database are the same, once one of the input files is opened with WordPad, any file with the same extension will be opened automatically in WordPad with just a mouse double-click.

TPLF input and output data files for different simulation cases are typically stored in subdirectories, along with a copy of the TPLF executable program (refer to VPS program description section).

After the User provides the requested TPLF Driver File, the User is asked whether vehicle constant current or forced reduced performance modeling is desired. The User enters “A” or “B” as required. If constant current modeling is desired, the program normally runs to completion, providing a message if the simulation is completed successfully. Normally the only error that might occur once the program has successfully read and processed the input files is a "train not found" error. This signifies that a positive or negative return "track" branch was not found for a specific train location. Usually this means that a branch was omitted, or that a track branch number is incorrect. If this occurs, the program writes the location and track number of the train that can't find a positive and/or negative return conductor to the screen and to the Summary Output File, and program execution stops.

If the User requests forced reduced performance (FRP) modeling, the program prompts for input of the following 3 parameters that define the reduction in propulsion current as voltage at the train drops. This reduction, known as the “current taper”, is typically linear and is expressed in amps per volt. It represents the number of amps that are reduced per vehicle for each volt of voltage reduction once the line voltage drops below the FRP triggering threshold. The current version of the TPLF program uses a single linear FRP characteristic which represents most train types. A two-piece linear option will be added in the future to model vehicles with more complex FRP capabilities, such as the WMATA series 7000 train.

FRP triggering voltage threshold: This is the maximum voltage at the vehicle below which FRP operates (highest voltage for propulsion current taper characteristic). This is entered in Volts with a decimal point (real number).

FRP minimum train voltage for taper: This is the minimum voltage at the vehicle at which FRP stops operating (lowest voltage for propulsion current taper). This is entered in Volts with a decimal point (real number).

Amps/volt propulsion current taper: The Amperes of propulsion current that are reduced for each volt of voltage reduction. This is entered in Amps with a decimal point (real number). For example, if full propulsion current is 1,200 Amps and we want FRP to start at 600 Vdc and reduce propulsion current to 50% (600 A) at 450 Vdc, the propulsion current taper would be ΔI / ΔV, or 600 A / 150 V, which is 4 Amps/Volt.

The three FRP parameters entered above are written to the Summary Output File for recordkeeping.

Example Input Data Files The following “example case” TPLF data files are included with this manual. When used with the TPLF_93.EXE program, the user can observe program operation, output, and the effects of varying parameters. The example case is same Norfolk, VA LRT system example that was provided for the Vehicle Power Simulator. All TPLF input data files should be copied to a single TPLF directory; program output will be written to the same directory.



Name of Input Data File Data File Type LF-BASE2.HRT TPLF Driver File SY-BASE.HRT System File AM-BASE.HRT Ammeter File DI-BASE2.HRT Dispatch File CL-75MIN.HRT Clock File LP-EB-2.HRT Load Profile (Eastbound) LP-WB-2.HRT Load Profile (Westbound)

Program Usage and Liability As noted above, the ETSA program modules have been used for a wide variety of projects over a period of many years. However, they are not warranted to be error-free. If used for engineering purposes, results (program input and output) should be verified for accuracy using calculation methods such as hand calculations, spreadsheets, Mathcad, etc. This is a normal procedure for project quality assurance. Anyone using this software automatically accepts the following The User accepts the programs "as is." No warranties as to the function or use of the programs, are provided, whether express, implied, or statutory, including, without limitation, any implied warranties of merchantability or fitness for particular purpose. The entire risk as to the quality and performance of the programs is with the User. The author does not warrant that the functions contained in the licensed programs will meet licensee's requirements or that the operation of the programs will be uninterrupted or error free.



IV. Voltage Profile Program (VOLTPRO)

Introduction The TPLF program writes train voltage data to the Train Voltage Output File during each network simulation “snapshot”. This data is a listing of all calculated train voltages and associated rail potentials, train location and power sections occurring during each simulation snapshot, organized by snapshot. It cannot be plotted in this format.

The purpose of the VOLTPRO program is to obtain the location and voltages of a single train as it travels through the system, and to output that information into an ASCII data file for plotting using Excel. The voltages and locations of all the trains traveling on the system could be plotted in what is sometimes called a “scatter plot”, but the information provided by plotting a single train is easier to understand, so this is the approach currently used. If unexpected gaps appear in the plots, this also provides an indication that the trains may not have been scheduled correctly in a simulation. Introduction The VOLTPRO program (voltpro.exe) and the Train Voltage Output File containing the desired train voltage information must both be located in the same folder.

Working from Windows Explorer, double-click the voltpro.exe filename to start the program.

Enter the name of the Train Voltage File (VO File) at the prompt, followed by <enter>.

If the VO File can’t be found, you will be notified (make sure you typed it correctly, and make certain it is in the same directory as the program file).

The program will read through the VO File, provide a screen listing of all the train types found in that file, and ask you which one you would like to plot. Type the desired train ID, followed by <enter>.

When prompted, enter a name for the program output file (using the train ID as the output file name works well). If you add the .PRN file extension, Excel will automatically recognize the file as a “PRN” (space-delimited) text file, which is helpful (for example, “TEST.PRN”).

You will get a message that the program has successfully terminated.

Repeat this sequence as needed to obtain plotting information for all train types to be plotted.

Excel Plotting Introductions The format of a typical VOLTPRO ASCII output file is shown below (first few lines only).

=========== FILENAME: VOLTS_NB.PRN =========== VOLTAGE PROFILE FOR VEHICLE ID: 3S-NB CREATED FROM SOURCE FILE VO-4SUBS_TST.CSC ON 1/10/2014 TRAIN RAIL POWER MILEPOST VOLTAGE VOLTAGE SNAPSHOT SECTION 3.642 759.9 -0.6 8: 5:47 3.644 737.1 2.9 8: 5:48 3.646 714.5 6.7 8: 5:49 3.648 696.6 8.9 8: 5:50 3.652 687.2 10.1 8: 5:51



Start Excel, and use the File/Open command sequence to find the data file you’ve just created, using the “Text Files (*.prn; *.txt; *.csv)“ search criteria in the “Files of Type” menu drop down box.

The Excel “Text Import Wizard” screen should appear. Since the text information at the top of the file is not needed for plotting, start the import below this information (if you use row 8 or 9, you will import the column headers, which is helpful). Enter the desired number in the ‘Start import at row:” box, and click <next>.

Drag the column breaks so that you end up with three data columns (milepost, voltage and snapshot). The snapshot column is not used for plotting at this time, but is helpful for reference. Click <next>.

Confirm that the “Column data format” check box for “General” is selected, and click <Finish>. This should result in an Excel file with three columns of data.

A train voltage plot (Excel calls them “charts”) can be made directly from this data. However, since these charts take considerable time to set up “from scratch”, it is usually much more efficient to copy the voltage and location data from the file created by VOLTPRO, and paste it over the same information in another Excel file in which a train voltage plot has already been set up.

Some notes on creating Excel charts from TPLF output files.

1. It is helpful to show substation locations and passenger station locations on the train voltage plots, as well as minimum allowable voltage thresholds. These are entered in separate columns (Review an existing Excel train voltage plot file to see how this is accomplished). Substation and passenger locations are “data labels”.

2. Since the number of voltage-location data points can vary for different simulations on the same system, the positioning of substation and passenger station locations may need to adjusted when voltage and location data is pasted into it from another simulation.

3. When creating a chart from scratch, be sure to select a “scatter” type chart with solid lines. (“Line” type charts do not model the x axis to a consistent numerical scale). Also, insert the chart on its own worksheet (tab).



V. Rail Potential Modeling

Introduction The negative return portion of modern direct current (dc) light and heavy rail power systems is intentionally isolated from ground under normal operations to the maximum extent practical. The purpose of this electrical isolation is the prevention of stray dc current flow into the earth and nearby infrastructure. The high levels of stray current flow associated with alternate methods of dc traction power system grounding, such as direct grounding and diode grounding, have rendered them essentially obsolete.

The steel running rails (tracks), which are the largest component of a negative return system, are isolated from the track bed by the use of components such as elastomeric pads and insulated fasteners. The isolation between tracks and ground is not perfect, with resistance-to-ground initial installation test values of 250 and 500 Ohms for 1,000 feet of single track being typical for ballasted and direct fixation track, respectively. Although the initial levels of isolation present at system commissioning tend to degrade with time, the resulting isolation of the tracks from ground remains sufficient to permit the buildup of voltage.

For dc traction systems in particular, the lack of an intentional connection between the tracks and ground allows voltage differences to occur along the rails, and between the rails and nearby structures. These voltage differences are caused by the flow of current through the running rails back to the source substations. The voltage difference along the rails is the result of voltage drop across the rail impedance, which is often termed “longitudinal voltage drop”. “Rail potential” is the difference in voltage between the tracks and ground at a specific location. “Ground” in this instance means “remote earth” and “earth” in the terminologies of American (IEEE) and European (IEC, EN) standards and codes, respectively (a zero potential reference).

Rail potential at any location along the tracks varies significantly due to the passage of trains, with the higher values typically corresponding to periods of peak train acceleration and therefore lasting on the order of seconds. The resulting peak rail potentials may or may not be significant, being dependent on the magnitude of the train load currents, the resistance of the rail return circuit, and the degree of electrical isolation of the tracks from earth. The distance between substations and the outage of complete substation rectification equipment also affect rail potentials, since these impact the resistance of the rail return circuit.

Rail Potential Modeling with TPLF Rail potential is typically calculated by one of two methods. The method that is most analytically exact involves the application of Maxwell’s equations (transmission line theory), treating the running rails as long, “leaky” transmission lines with distributed parameters (continuously distributed resistance R and conductance G). This method becomes highly complicated for alternating current electrification systems in particular due to the interactions between circuit elements (mutual coupling). Even for direct current systems, it requires the use of simplifying assumptions that make it difficult to apply to rail systems with multiple substations and multiple trains in simultaneous operation on multiple tracks. In addition, it is not adaptable to the matrix-oriented electrical network solution methods that are used in modern load flow simulation programs including TPLF. For these reasons this method is typically used for theoretical purposes only such as for the illustration of rail potential concepts, and for validating the methods of load flow simulation programs for simple system configurations.

A network solution using the traditional “nodal formulation” requires that a traction power system be represented as an electrical network composed of “nodes” and “branches”. The branches represent electrical equipment and conductors such as rectifiers, bus bars, contact systems, running rails, cables, and ground connections. The nodes represent the connection points between these circuit elements. Obtaining a mathematical solution to this network involves the conversion of the branch impedances into an admittance (Y) matrix. This procedure establishes a system of equations that



must be solved simultaneously using numerical methods to obtain the voltage at each node. Once the node voltages have been determined, the current flows through each branch can be calculated.

Using the network solution method to calculate dc rail potential requires that the running rails between substations be represented as discrete resistors. The distributed resistance between the running rails and remote earth, which is better known as “conductance”, is also represented by discrete resistors connected between the rails and the circuit ground plane, as illustrated in the above Figure, which represents just a portion of a track model. This arrangement enables the voltage between the running rails and remote earth (rail potential) to be calculated at the resistor “nodes” when the electrical network is solved.

The network solution method, which is the method used by the TPLF program, divides the running rails between substations into smaller segments, each with an equivalent resistance to remote earth. This simplification enables the calculation of rail potentials resulting from typical traction power system operating conditions with practical load flow simulation programs such as TPLF that explicitly model the negative return electrical network. It is up to the User to determine the optimum spacing between the connections from the running rails to remote earth (“GROUND” nodes). Some trial and error is recommended. However, since the TPLF program solves exceptionally quickly, additional grounding nodes will not significantly affect program performance.

Negative Grounding Devices In the United States at present, the use of active type rail potential management devices has been limited primarily to dc traction substation locations. When installed in substations, these devices are connected between the dc negative bus and the substation grounding grid. For this reason, they are commonly referred to as “negative grounding devices”. They are also known as “automatic grounding switches”, “rail potential control devices”, and “grounding contactors”. They perform a function similar to that of a voltage limiting device, but do not necessarily comply with EN 50122-1.

In addition to limiting the rail potential in the vicinity of the substation, substation-installed NGDs can assist in the detection and clearing of positive-to-earth ground faults external to the dc switchgear. A very simplified circuit diagram illustrating the configuration of a typical NGD application for a 750 Vdc nominal system is shown below in the accompanying Figure. This Figure illustrates the result of a catenary-to-ground fault, although the result will be the same for any form of dc ground fault. The NGD is normally in an open state (non-conducting). As long as it remains open, significant fault current cannot flow back to the substation dc negative bus, since there is only a very high resistance return path available to it. A small amount of fault current will flow into the rails near the fault via the leakage/shunt resistance of the rails, in proportion to how well they are insulated from earth. Some fault current may also return to the negative bus through stray current drainage circuits in older rail transit systems, but drainage circuits are typically avoided on modern dc traction systems. After the NGD senses a triggering voltage difference across it and closes, the fault current will flow through the earth into the substation grounding grid.

The current from a remote ground fault will typically return to the NGD directly through the earth via the grounding grid, which rarely has a resistance to remote earth Rg of less than one Ohm. If Rg is an unusually-low ½ Ohm and the substation output voltage is 750 Vdc, then the maximum fault current from a remote fault will be 1,500 Amperes (less for an arcing fault). If stray current drainage facilities are present in the substation, these may also conduct some of the ground fault current, but directly to



the negative bus, bypassing the NGD (see figure). If a system earthing conductor is present (a European practice), this could direct some of the fault current directly to the grounding grid and through the NGD. However, unless there is a direct metallic connection between the faulted conductor and the grounding grid, it does not appear that a high magnitues of fault current will flow through NGD’s located in substations, particularly in light rail substations.

Although the use of NGDs is common in the USA, particularly on newer light rail lines, very little information is available that describes how effective they are at reducing rail potential at locations other than near substations, and their long-term impact on stray current corrosion. Research needs to be performed in this area.

NGD Modeling with TPLF At present the TPLF program does not model automatic NGD operation (this feature will eventually be added). However, the impact on the traction power system of a closed NGD can be modeled at any location along the ROW by adding a low-resistance branch between the running rail and earth (a “GROUND” node in the System File) at the desired location. To model a closed NGD at a substation, a low-resistance branch would be added between the substation negative bus node and earth. The resulting maximum current through the closed NGD will be reported in the Summary Output File, and the system impacts will be reported in the other various available output files. The current through the closed NGD should be relatively low if the running rails are well isolated from earth.



VI. Miscellaneous TPLF Procedures

Procedure for Performing Multiple Rectifier Outage Simulation Scenarios When there are two or more rectifiers per substation

1. In the TPLF driver file (the list of filenames), give the summary output file an appropriate name for the outage scenario (up to 20 characters allowed); “turn off” all other output files as desired by preceding each file name with an “N”, followed by a blank space. WordPad is recommended for editing the TPLF driver file; remember to save changes before minimizing or closing the WordPad window in Explorer.

2. In the TPLF system file, write the name of the substation with the outage in one of the 4 lines of “header text” that get written to the summary output file. This is for good record-keeping purposes (assuming that you want to be organized about this).

3. In the TPLF system file, change the rectifier resistance and 100% rated current quantities for the affected substation to reflect the number of rectifiers remaining after the outage. For example, if the substation has two 2.5 MW rectifiers rated 600 Vdc with 5.5% voltage regulation (CTA), the rectifier equivalent resistance between 0 to 100% of full load current, and the 100% rated current quantities, should be as follows:

Equivalent Substation

Ohms

Total Substation 100% Rated

DC Amps Both rectifiers in service 0.00400 8333 One rectifier in service 0.00800 4167

When there is one rectifier per substation

1. In the TPLF driver file, give the summary output file an appropriate name for the outage scenario (up to 20 characters allowed); “turn off” all other output files not desired by preceding each file name with an “N”.

2. In the TPLF system file, write the name of the substation with the outage in one of the 4 lines of “header text” that get written to the summary output file.

3. In the TPLF system file, indicate a substation outage for the affected substation by inserting the letters ‘OUT’ in the appropriate right-hand column on the same line as the rectifier data for the substation rectifier to be taken out of service. This will simulate the power system with this substation’s source of power removed (but with all other equipment connected), similar to opening the rectifier anode (ac) and/or cathode breaker. Remember to save changes to the file.

4. After the simulation has finished, look at the resulting summary output file header in WordPad to make certain that the appropriate filename and header text is present before printing the file.



VII. Example TPLF Output Charts and Tables

Several examples of Excel charts and tables created from TPLF program output data are provided on the following pages for reference. These are only a few of the many possibilities. The train positive voltage profiles illustrate the voltage between the vehicle current collector and the running rails as the vehicle moves along the right-of-way. The negative voltage profiles provide the voltage between the running rails and remote earth at the location of the train. The voltage between any negative node and remote earth can also be plotted as a function of time, if desired (for example, the rail voltage versus time at station platform locations).

R. W. Benjamin Stell c:\users\benjamin\documents\etsa\manual\web_site\etsa_manual_version_1.3_2-13-2016.docx`

Waterloo LRT Load Flow Study Train Voltage ProfileWaterloo LRT Load Flow Study- Train Voltage Profile2 Car Trains (Bombardier TCLRV) at 5 Minute Headways, 12 Main Line 1.5 MW TPSS( ) y ,

System Normal Case - All Equipment in Service (Northbound Train Shown)

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Min Acceptable VoltageMin. Acceptable Voltage

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Train Position (km)Train Position (km)

EXHIBITEXHIBITTRAIN VOLTAGE 1-1 9/24/2013

Load Flow Simulation Study for the CATS LYNX Blue Line South Corridor

Rectifier Loading Results � Peak Period Operation

Existing System Existing South Corridor Traction Power Substations

All Equipment in Service

3 Car AW3 Trains at 7.5 Minute Headways Inbound & Outbound

Simulated Load Current Rectifier Load Ratings at 750 Vdc � See Note 1 Rectifier Loading Analysis

Substation Peak 2 Hr 1 Min. 15 Sec. 2 Hr RMS Loading Results

Rectifier RMS (Instan� Continuous IEEE IEEE IEEE Combined % of % of % of 2 Hr

Substation Capacity (Continuous) taneous) Ratings Ratings Ratings Ratings Rating Continuous 2 Hour Combined

Name (kW) Amps Amps (Amps) (Amps) (Amps) (Amps) (Amps) Rating Rating Rating

TPSS #1 1,500 938 2,974 2,000 3,000 6,000 9,000 3,206 46.9 31.3 29.3

I�485

TPSS #2 1,500 1,381 4,602 2,000 3,000 6,000 9,000 3,206 69.1 46.0 43.1

Sharon Rd. West

TPSS #4 1,500 1,475 5,396 2,000 3,000 6,000 9,000 3,206 73.8 49.2 46.0

Archdale Rd.

TPSS #6 1,500 1,204 3,863 2,000 3,000 6,000 9,000 3,206 60.2 40.1 37.6

Woodlawn Rd.

TPSS #8 1,500 1,191 3,134 2,000 3,000 6,000 9,000 3,206 59.6 39.7 37.1

Mainline

TPSS #10 1,500 1,110 3,817 2,000 3,000 6,000 9,000 3,206 55.5 37.0 34.6

Carson

TPSS #11 1,500 1,166 3,575 2,000 3,000 6,000 9,000 3,206 58.3 38.9 36.4

9th Street

TPSS #12 1,500 1,331 2,734 2,000 3,000 6,000 9,000 3,206 66.6 44.4 41.5

VLMF (future)

TPSS #13 1,500 1,183 3,479 2,000 3,000 6,000 9,000 3,206 59.2 39.4 36.9

Craighead (future)

NOTES

1. Rectifier load ratings per IEEE 1653.2 Extra Heavy Traction Service. The 2 hour combined rating is 1.603 times

the continous rating of the rectifier. It represents the rms equivalent of the entire 2 hour Extra Heavy Traction load cycle.

2. The loads shown for the future VLMF TPSS are for main line operation only.

3. The loads shown do not reflect the use of LRV forced reduced performance capability.

EXHIBIT

RECTIFIERS EXISTING 1 2/12/2013

Load Flow Simulation Study for the Waterloo LRTRectifier Loading Results - Peak Period Operation

Results with Individual TPSS Outages (OCS Continuity is Provided At the Affected Substation During the Outage)2 Car Trains at 5 Minute Headways Northbound & Southbound, Bombardier Flexity w/200 Passengers per Car

RESULTS WITH INDICATED INDIVIDUAL SUBSTATION OUTAGESSYSTEM NORMAL LOADS ON OTHER SUBSTATIONS WITH INDICATED SUBSTATION OUTAGE

Total Substa. % of TPSS #1 TPSS #2 TPSS #3 TPSS #4 TPSS #5 TPSS #6 TPSS #7 TPSS #8 TPSS #9 TPSS #10 TPSS #11 TPSS #12

Rectifier Contin. Substation % of % of % of % of % of % of % of % of % of % of % of % of

Substation Capacity Rating RMS Continuous RMS Contin. RMS Contin. RMS Contin. RMS Contin. RMS Contin. RMS Contin. RMS Contin. RMS Contin. RMS Contin. RMS Contin. RMS Contin. RMS Contin.

Name (kW) Amps Amps Rating Amps Rating Amps Rating Amps Rating Amps Rating Amps Rating Amps Rating Amps Rating Amps Rating Amps Rating Amps Rating Amps Rating Amps RatingTPSS #1 1,500 2,000 748 37.4% 1,106 55.3% 810 40.5% 770 38.5% 756 37.8% 750 37.5% 748 37.4% 748 37.4% 748 37.4% 748 37.4% 748 37.4% 748 37.4%

TPSS #2 1,500 2,000 807 40.4% 1,323 66.2% 1,017 50.9% 878 43.9% 832 41.6% 813 40.7% 809 40.5% 807 40.4% 807 40.4% 807 40.4% 807 40.4% 807 40.4%

TPSS #3 1,500 2,000 697 34.9% 810 40.5% 959 48.0% 1,011 50.6% 797 39.9% 724 36.2% 706 35.3% 699 35.0% 698 34.9% 697 34.9% 697 34.9% 697 34.9%

TPSS #4 1,500 2,000 813 40.7% 846 42.3% 887 44.4% 1,076 53.8% 1,177 58.9% 904 45.2% 841 42.1% 819 41.0% 815 40.8% 814 40.7% 814 40.7% 814 40.7%

TPSS #5 1,500 2,000 1,047 52.4% 1,056 52.8% 1,066 53.3% 1,107 55.4% 1,306 65.3% 1,448 72.4% 1,165 58.3% 1,071 53.6% 1,053 52.7% 1,049 52.5% 1,048 52.4% 1,048 52.4%

TPSS #6 1,500 2,000 1,282 64.1% 1,284 64.2% 1,286 64.3% 1,295 64.8% 1,337 66.9% 1,623 81.2% 1,825 91.3% 1,386 69.3% 1,308 65.4% 1,288 64.4% 1,283 64.2% 1,282 64.1%

TPSS #7 1,500 2,000 1,348 67.4% 1,349 67.5% 1,350 67.5% 1,352 67.6% 1,364 68.2% 1,444 72.2% 1,870 93.5% 1,716 85.8% 1,438 71.9% 1,368 68.4% 1,354 67.7% 1,350 67.5%

TPSS #8 1,500 2,000 1,210 60.5% 1,210 60.5% 1,210 60.5% 1,211 60.6% 1,214 60.7% 1,232 61.6% 1,323 66.2% 1,627 81.4% 1,611 80.6% 1,295 64.8% 1,232 61.6% 1,218 60.9%

TPSS #9 1,500 2,000 989 49.5% 989 49.5% 990 49.5% 990 49.5% 991 49.6% 996 49.8% 1,024 51.2% 1,113 55.7% 1,481 74.1% 1,285 64.3% 1,061 53.1% 1,015 50.8%

TPSS #10 1,500 2,000 933 46.7% 933 46.7% 933 46.7% 933 46.7% 933 46.7% 934 46.7% 941 47.1% 960 48.0% 1,040 52.0% 1,235 61.8% 1,263 63.2% 1,049 52.5%

TPSS #11 1,500 2,000 853 42.7% 853 42.7% 853 42.7% 853 42.7% 853 42.7% 854 42.7% 855 42.8% 861 43.1% 883 44.2% 932 46.6% 1,209 60.5% 1,340 67.0%

TPSS #12 1,500 2,000 723 36.2% 723 36.2% 723 36.2% 723 36.2% 723 36.2% 723 36.2% 724 36.2% 725 36.3% 731 36.6% 744 37.2% 814 40.7% 1,076 53.8% OUT

OUT

OUT

OUT

OUT

OUT

OUT

OUT

OUT

OUT

OUT

OUT

Waterloo_Rectifier_Loading.xlsxEXHIBIT

RECTIFIER LOADING - OUTAGES 9/24/2013

Load Flow Simulation Study for the Waterloo LRTSubstation Cable Loading Results - Peak Period Operation

12 New 1.5 MW TPSSAll Equipment in Service

2 Car Trains at 5 Minute Headways Northbound & Southbound, Bombardier Flexity w/200 Passengers per Car

Continuous CircuitSimulated Load Currents Loading

Circuit RMS 1 Sec. Circuit Per CentCable Data RMS Amps Peak Rating of Circuit

Substation Dc Circuit Name # Size Amps per Cable Amps (Amps) RatingTPSS #1 Track 1, North (F1) 2 500 kcmil 223 112 1,555 972 22.9%

Conestoga Mall Track 2, North (F2) 2 500 kcmil 211 106 1,553 972 21.7%STA 00+145 Track 1, South (F3) 2 500 kcmil 405 203 1,299 972 41.7%

Track 2, South (F4) 2 500 kcmil 396 198 1,171 972 40.7%Neg. Returns 4 500 kcmil 748 187 -1,679 1,944 38.5%

TPSS #2 Track 1, North (F1) 2 500 kcmil 340 170 1,034 972 35.0%Northfield Drive Track 2, North (F2) 2 500 kcmil 426 213 1,204 972 43.8%

STA 01+550 Track 1, South (F3) 2 500 kcmil 415 208 1,249 972 42.7%Track 2, South (F4) 2 500 kcmil 163 82 914 972 16.8%Neg. Returns 4 500 kcmil 807 202 -1,943 1,944 41.5%

TPSS #3 Track 1, North (F1) 2 500 kcmil 299 150 814 972 30.8%Bearinger Road Track 2, North (F2) 2 500 kcmil 282 141 1,455 972 29.0%

STA 02+935 Track 1, South (F3) 2 500 kcmil 284 142 1,004 972 29.2%Track 2, South (F4) 2 500 kcmil 408 204 1,526 972 42.0%Neg. Returns 4 500 kcmil 697 174 -1,423 1,944 35.9%

TPSS #4 Track 1, North (F1) 2 500 kcmil 345 173 1,306 972 35.5%Columbia Street Track 2, North (F2) 2 500 kcmil 394 197 1,481 972 40.5%


TPSS #5 Track 1, North (F1) 2 500 kcmil 363 182 1,245 972 37.3%F.D. Bauer Drive Track 2, North (F2) 2 500 kcmil 394 197 1,215 972 40.5%

STA 05+640 Track 1, South (F3) 2 500 kcmil 476 238 1,366 972 49.0%Track 2, South (F4) 2 500 kcmil 489 245 1,645 972 50.3%Neg. Returns 4 500 kcmil 1,047 262 -1,992 1,944 53.9%

TPSS #6 Track 1, North (F1) 2 500 kcmil 518 259 1,360 972 53.3%Mt. Hope Street Track 2, North (F2) 2 500 kcmil 420 210 1,433 972 43.2%

STA 07+365 Track 1, South (F3) 2 500 kcmil 464 232 1,348 972 47.7%Track 2, South (F4) 2 500 kcmil 428 214 1,189 972 44.0%Neg. Returns 4 500 kcmil 1,282 321 -2,374 1,944 65.9%

TPSS #7 Track 1, North (F1) 2 500 kcmil 385 193 1,338 972 39.6%Transit Hub Track 2, North (F2) 2 500 kcmil 499 250 1,324 972 51.3%STA 08+580 Track 1, South (F3) 2 500 kcmil 489 245 1,389 972 50.3%

Track 2, South (F4) 2 500 kcmil 501 251 1,491 972 51.5%Neg. Returns 4 500 kcmil 1,348 337 -2,558 1,944 69.3%

TPSS #8 Track 1, North (F1) 2 500 kcmil 604 302 2,232 972 62.1%Cedar Street Track 2, North (F2) 2 500 kcmil 522 261 2,037 972 53.7%STA 10+230 Track 1, South (F3) 2 500 kcmil 363 182 1,308 972 37.3%

Track 2, South (F4) 2 500 kcmil 412 206 1,240 972 42.4%Neg. Returns 4 500 kcmil 1,210 303 -2,312 1,944 62.2%

TPSS #9 Track 1, North (F1) 2 500 kcmil 383 192 1,329 972 39.4%Charles/Ottawa Track 2, North (F2) 2 500 kcmil 339 170 1,061 972 34.9%


TPSS #10 Track 1, North (F1) 2 500 kcmil 467 234 1,414 972 48.0%Conestoga Pkwy Track 2, North (F2) 2 500 kcmil 439 220 1,581 972 45.2%


TPSS #11 Track 1, North (F1) 2 500 kcmil 443 222 1,314 972 45.6%Blockline Road Track 2, North (F2) 2 500 kcmil 421 211 1,236 972 43.3%STA 14+375 Track 1, South (F3) 2 500 kcmil 322 161 1,220 972 33.1%


TPSS #12 Track 1, North (F1) 2 500 kcmil 437 219 1,263 972 45.0%Wilson Avenue Track 2, North (F2) 2 500 kcmil 429 215 1,374 972 44.1%STA 15+990 Track 1, South (F3) 2 500 kcmil 197 99 1,575 972 20.3%


486 per cable based on 2 cables/duct, 4 occupied ducts486 per cable based on 2 cables/duct, 4 occupied ducts

Positive 500 kcmil ampacity (amps): Negative return 500 kcmil ampacity (amps):

Cable ampacity (rating) is based on 75% daily load factor, 90° C Operating temp, RHO 90 earth, 2‐500 kcmil cables in each duct, 4

ducts occupied in an 8‐way duct bank.

EXHIBIT CABLES N-1 9/24/2013

HRT Light Rail Transit Project

Traction Power Load Flow Simulation Study - Task 4.8

Traction Power Substation OCS Current Flows During Peak Service

2-Car Trains at 7.5 Minute Headways in Both Directions

Traction Power System Layout Per PE Phase (Six Main Line 1.0 MW Substations and Parallel Feeders)

NORMAL OPERATION (All Equipment in Service)

Circuit Circuit System Current Flow

Location Conductor Type & Rating Normal as % of

Substation Track (STA) Type kcmil (Amps) (RMS Amps) Ckt. Rating

TPSS #1 WB 105+60 catenary 350 + 500kcmil 1,095 147 13.4%

EB 105+60 catenary 350 + 500kcmil 1,095 246 22.4%

TPSS #2 WB 142+00 contact wire 350 kcmil 467 75 16.0%

parallel fdr. 2-500 886 214 24.2%

Total current in contact wire & feeder (A): 289

EB 142+00 contact wire 350 kcmil 467 37 7.8%

parallel fdr. 2-500 kcmil 886 105 11.8%


WB 142+50 contact wire 350 kcmil 467 79 16.9%

parallel fdr. 2-500 886 227 25.6%





TPSS #3 WB 232+30 contact wire 350 kcmil 467 72 15.4%

parallel fdr. 2-500 886 206 23.3%





WB 232+80 catenary 350 + 500kcmil 1,095 250 22.8%



TPSS #4 EB 332+10 catenary 350 + 500kcmil 1,095 457 41.7%









NOTES:

1. Overhead contact system ampacities (current-carrying capacities) are calculated per

IEEE Std. 738 and the AREMA Manual Chapter 33 (75 °C conductor, 40 °C ambient, 2 fps wind + sun).

2. Parallel Feeder: 2-500 kcmil CU in 4" PVC duct bank, 2 ckts./duct bank, 75% load factor.

2/26/2007

EXHIBIT

Overhead Contact System #1

Benjamin

Text Box

Example that utilized the Wiretemp support program to calculate contact wire and messenger operating temperatures

EXHIBITTRAIN VOLTAGE #1 4/2/2016

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CATS LYNX Extension Load Flow Study: Train Rail-to-Earth Voltage Profile1.5 MW TPSS - 3 Car Trains at 7.5 Minute Headways

Baseline Case - All Equipment in Service (Inbound Train Shown)

Passenger Station Locations

Simulated Running Rail Voltage

Substation LocationsDirection of Travel

HRT Light Rail Transit Project Task 4.8

Load Flow Simulation Results: Rail Voltage Rise at Location of Highest VoltageSystem Normal: 2-Car Trains at 7.5 Minute Headways

Voltage-to-Ground (Remote Earth) at Ballantine Station

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2/26/2007

EXHIBIT

RAIL POTENTIAL RISE #2

Documents

PROGRAM INSTRUCTION MANUAL - storage.googleapis.com · perform exte nsive traction power system load flow studies for the MBTA Green and Red Lines in Boston, Massachusetts. After