Chair: Siri Varadan, Nexant, Inc. Panelists: Elham Makram, Clemson University Thomas Baldwin, Florida State University Mark McGranaghan, Electrotec Concepts

PANEL DISCUSSION P5Impact of Distributed Generation on

Harmonics and Power Quality

Chair: Chair: Siri Varadan,Siri Varadan, Nexant, Inc. Nexant, Inc.

Panelists:Panelists:Elham Makram,Elham Makram, Clemson UniversityClemson University

Thomas Baldwin,Thomas Baldwin, Florida State UniversityFlorida State UniversityMark McGranaghan,Mark McGranaghan, Electrotec ConceptsElectrotec Concepts

2DG Conference, Clemson, SC

March 13-15, 2002

Presentation Topics and OrderPresentation Topics and Order

Effect of Harmonics on Distributed Generation – Effect of Harmonics on Distributed Generation – – Elham MakramElham Makram

Harmonic and Distributed Generation Interaction Issues in Harmonic and Distributed Generation Interaction Issues in the U.S. Navy All-Electric Ship Program –the U.S. Navy All-Electric Ship Program –– Tom BaldwinTom Baldwin

PQ Issues for DG Applications –PQ Issues for DG Applications –– Mark Mc GranahanMark Mc Granahan

Software Aspects of PQ in a DG Context –Software Aspects of PQ in a DG Context –– Siri VaradanSiri Varadan

General Discussion General Discussion


March 13-15, 2002

‘‘Independent’ Modules to Ensure Independent’ Modules to Ensure Vendor-Independence in Utility-Vendor-Independence in Utility-wide PQ Monitoring Systemswide PQ Monitoring Systems

by by

Mehmet Kemal CelikMehmet Kemal Celik


March 13-15, 2002

Overview of the PresentationOverview of the Presentation

IntroductionIntroduction Modular System DesignModular System Design BenefitsBenefits Functional DesignFunctional Design A Customized Analysis ExampleA Customized Analysis Example ConclusionsConclusions


March 13-15, 2002

Power Quality Monitoring Power Quality Monitoring SystemsSystems

Integrated systems of several PQ monitors are being set upIntegrated systems of several PQ monitors are being set up– increasing number of monitorsincreasing number of monitors– emerging computer technologies on hardware and software areaemerging computer technologies on hardware and software area– different architectures that serve all PQ monitors with a single large different architectures that serve all PQ monitors with a single large

databasedatabase» client-serverclient-server» Intranet/InternetIntranet/Internet


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Power Quality Monitoring Power Quality Monitoring SystemsSystems

Such integrated designs have several advantagesSuch integrated designs have several advantages– efficient and fast analysis of large volumes of dataefficient and fast analysis of large volumes of data– establish centralized PQ dataestablish centralized PQ data– usage of standard PQ indices within the utilityusage of standard PQ indices within the utility– standardization of customer complaint evaluationstandardization of customer complaint evaluation– modular, expendable and portable system designmodular, expendable and portable system design– reduction in system maintenance and expansion costsreduction in system maintenance and expansion costs– standard data analysis tools on LAN/WAN, Intranet, standard data analysis tools on LAN/WAN, Intranet,

etc.etc.– centralized security systemcentralized security system


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Main PQ Monitoring System Main PQ Monitoring System ComponentsComponents

Communication System - physical media (fibre optics, Communication System - physical media (fibre optics, copper, wireless, etc), modems (DSL, telephone, etc.), copper, wireless, etc), modems (DSL, telephone, etc.), Ethernet network components (switches, routers, etc), etc.Ethernet network components (switches, routers, etc), etc.

Information Technology (IT) System - computers (data Information Technology (IT) System - computers (data servers, polling stations, client stations, etc), system servers, polling stations, client stations, etc), system software (operating system, etc), database system, software (operating system, etc), database system, protocol converters, user applications (GUI, analytical protocol converters, user applications (GUI, analytical applications, alarm and information dispersal software, applications, alarm and information dispersal software, web publishing, etc.), etc. web publishing, etc.), etc.

Monitoring System - instrumentation (PQ monitors, Monitoring System - instrumentation (PQ monitors, RTUs, sensors, etc), data retrieval and configuration RTUs, sensors, etc), data retrieval and configuration software, etcsoftware, etc


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PQ Monitoring System PQ Monitoring System ComponentsComponents

Monitoring system

WAN

Pollingserver

ODBCdatabase

Database/Applicationserver

Communication system

IT system

End users

PQ Monitors


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Implementation BenefitsImplementation Benefits Removes vendor dependencies - The best alternatives, Removes vendor dependencies - The best alternatives,

specific to meet all of the utility’s requirements, are usedspecific to meet all of the utility’s requirements, are used Easy implementation of analysis applications Easy implementation of analysis applications

– Analytical applications can be written that use the Analytical applications can be written that use the ‘standardized databases‘standardized databases

– Industry standard and vendor independent applications, each Industry standard and vendor independent applications, each best suited to meet utility’s requirementsbest suited to meet utility’s requirements

Ease in implementation of web reporting applications - Ease in implementation of web reporting applications - Latest web hosting and interactive site technologies can Latest web hosting and interactive site technologies can be used.be used.

Economic benefits - With several alternative systems, Economic benefits - With several alternative systems, price of the individual modules is more competitiveprice of the individual modules is more competitive


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Operational BenefitsOperational Benefits Maintenance of a standard databaseMaintenance of a standard database

– Allows cheap and regular maintenance. Allows cheap and regular maintenance. Facilitates easy database expansion. Single Facilitates easy database expansion. Single database ensures that there is no duplication of database ensures that there is no duplication of data from all current and potential future power data from all current and potential future power quality monitors.quality monitors.

Existing trained personnel can quickly Existing trained personnel can quickly come up to speed with the operation & come up to speed with the operation & maintenance of the system - No new maintenance of the system - No new elaborate training is necessaryelaborate training is necessary


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Future Expansion BenefitsFuture Expansion Benefits

Future subsystem components can be Future subsystem components can be selected solely on their merit - ‘Vendor-selected solely on their merit - ‘Vendor-independence’ independence’

Modular design allowsModular design allows– utilization of future advances in utilization of future advances in

instrumentation, communication, and software instrumentation, communication, and software technologiestechnologies

– utilization of upgrading without a major utilization of upgrading without a major investment in a complete system overhaulinvestment in a complete system overhaul


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Conceptual DesignConceptual Design Future expandability; plug-and-play concept

Database

Leased Lines or other media

Fiber Optics and DSL modems

Instrumentation

Database serverMeter server

LAN

End user

Required software - Communication- Data logging - Configuration

Current PQ meters Future PQ meters


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Functional DesignFunctional Design

ODBCDatabase

ProprietaryDatabase

User Interface

FutureApplications

PQ SystemCharacterization

WEB Reporting

Data Managing, Analysis& Reporting

Polling & Downloading

Applications Software


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Software ModulesSoftware Modules

Data from Communication server

ODBC database Application

server

3 component analysis

‘Basic’ softwareis installed on the Communication server

Harmonicanalysis

Web reporting

Event reporting

PQ characterization

Independent software modules, each of which can be modified/upgraded independently

Import/Export of datato other formats

(PQDIF , COMTRADE , etc)


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Data FlowData Flow

Data Managing & Reporting

Standard Interfaces

PQ System Characterization

WEB Reporting

Data Analysis & Reporting

Basic Software 3 Component Analysis Harmonics Analysis

Alarms

Proprietary Database

Polling

User Interface

ODBC Database

SQL


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Data Analysis and ReportingData Analysis and Reporting

ODBC compliant databaseOracle or SQL serverDisturbance reports

Event-based reportsPeriodic reportsTrending reports

Data Managing& Reporting

Data Analysis& Reporting

Expertsystem rules

ODBC data

CalculationModules

Display

Extract

ODBC compliant databaseOracle or SQL serverDisturbance reports

Event-based reportsPeriodic reportsTrending reports

Data Managing& Reporting

Data Analysis& Reporting

Rule-basedSystem

ODBC data

CalculationModules

Display

Extract


March 13-15, 2002

Data Analysis and ReportingData Analysis and Reporting Calculation ModulesCalculation Modules

– RMS, Root Mean Square, (voltage or current)RMS, Root Mean Square, (voltage or current)– SARFISARFI– Fundamental voltages and currents of Fourier seriesFundamental voltages and currents of Fourier series– Total voltage harmonic RMS, etc.Total voltage harmonic RMS, etc.

Expert system rules constitute a simple if-and-then Expert system rules constitute a simple if-and-then logic for combining windowed time data with logic for combining windowed time data with relational and topological datarelational and topological data

Extract module basically extracts the required Extract module basically extracts the required portion of the data from database tablesportion of the data from database tables

Display is in the form of graphs, tables and textDisplay is in the form of graphs, tables and text


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Typical Customization – Disturbance Typical Customization – Disturbance

AggregationAggregation Monitors track individual PQ disturbances Monitors track individual PQ disturbances A deviation on a single phase at a single instant in time will be A deviation on a single phase at a single instant in time will be

recorded as a disturbancerecorded as a disturbance An electrical system event may cause multiple disturbancesAn electrical system event may cause multiple disturbances For example, a single event: a tree branch blowing against a For example, a single event: a tree branch blowing against a

12kV line12kV line– It can result in voltage sags on more than one phase It can result in voltage sags on more than one phase – Sags will be recorded at PQ monitors located at different parts of feeder Sags will be recorded at PQ monitors located at different parts of feeder

with small time lags with small time lags – Arcing may generate wave shape faults as wellArcing may generate wave shape faults as well– Furthermore, fault current may result in a series of momentary outages, Furthermore, fault current may result in a series of momentary outages,

maybe followed by an interruption to servicemaybe followed by an interruption to service PQ monitoring should be able to relate all disturbances to the PQ monitoring should be able to relate all disturbances to the

actual cause (event)actual cause (event)


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Event Reporting Event Reporting (Disturbance (Disturbance Aggregation)Aggregation)

Feeder 2 events

Feeder 1 events

Feeder 1

M1

M2

M3

Feeder 2

M4

M5

M6

Voltage sag @t=1

Voltage sag @t=2

Momentary @t=3.5

Voltage sag @t=2.5

Events

Voltage sag @t=3.6

Voltage sag @t=4

Waveshape @t=4.5

Time (milliseconds)


March 13-15, 2002

Disturbance Aggregation Disturbance Aggregation

Two sets of disturbances, one on feeder 1, and another Two sets of disturbances, one on feeder 1, and another on feeder 2on feeder 2– voltage sag at voltage sag at t = 1t = 1 from PQ monitor 2 on feeder 1 from PQ monitor 2 on feeder 1

– Voltage sag from PQ monitor 1 at Voltage sag from PQ monitor 1 at t = 2 t = 2 on feeder 1on feeder 1

– Voltage sag from PQ monitor 3 at Voltage sag from PQ monitor 3 at t = 2.5 t = 2.5 on feeder 1on feeder 1

– Momentary outage from PQ monitor 2 at Momentary outage from PQ monitor 2 at t = 3.5 t = 3.5 on feeder 1on feeder 1

– Voltage sag from PQ monitor 4 at Voltage sag from PQ monitor 4 at t = 3.6 t = 3.6 on feeder 2on feeder 2

– Voltage sag from PQ monitor 5 at Voltage sag from PQ monitor 5 at t = 4 t = 4 on feeder 2on feeder 2

– Waveform distortion from PQ monitor 6 at Waveform distortion from PQ monitor 6 at t = 4.5 t = 4.5 on feeder 2on feeder 2


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Disturbance AggregationDisturbance Aggregation

Sequence of disturbancesSequence of disturbances

– all due to a tree branch blowing against a line on feeder all due to a tree branch blowing against a line on feeder 11

– Or, the disturbances on feeder 2 may be due to an Or, the disturbances on feeder 2 may be due to an independent event on feeder 2, such as lightningindependent event on feeder 2, such as lightning


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A properly sized moving time window that starts with the first event of the sequence will capture most of the practical situations, such as

event data that are from different phases on the same monitor

that are far apart from each other only by infinitesimal time intervals, etc.


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Window size of 3 milliseconds

Feeder 2 events

Feeder 1 eventsVoltage sag@t=1

Voltage sag@t=2

Momentary@t=3.5

Voltage sag@t=2.5

Voltage sag@t=3.6

Voltage sag@t=4

Waveshape@t=4.5

Time(milliseconds)

However, fixed size moving time windowing may cause inaccurate aggregation of events if it is not properly sized and used as the only decision criteria


March 13-15, 2002


Window size increased due to spatial information

Feeder 2 events

Feeder 1 events

Feeder 1

M1

M2

M3

Feeder 2

M4

M5

M6

Voltage sag @t=1

Voltage sag @t=2

Momentary @t=3.5

Voltage sag @t=2.5

Events

Voltage sag @t=3.6

Voltage sag @t=4

Waveshape @t=4.5

Time (milliseconds)

Same substation

If relational information is used with adaptive window sizing, accuracy and robustness is enhanced


March 13-15, 2002


In actual implementation, many more variables are considered, such as

severity of the eventssequence with respect to the location relational information and connectivityelectrical and geographical distancetypes of substation and feeder equipment usedprotection schemes utilized, etc.


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ConclusionsConclusions Modular – system components can be changed Modular – system components can be changed

without major modificationswithout major modifications Expandable – new monitoring systems can be Expandable – new monitoring systems can be

added without a complete system overhaul added without a complete system overhaul Easier to maintainEasier to maintain Standard unified set of tools across the usersStandard unified set of tools across the users Customizable applicationsCustomizable applications

Documents

Chair: Siri Varadan, Nexant, Inc. Panelists: Elham Makram, Clemson University Thomas Baldwin, Florida State University Mark McGranaghan, Electrotec Concepts