WAMS Specification___________________________________________________________________________

1.1 Introduction. Purpose of System

The contractor shall provide a Wide Area Monitoring System WAMS that shall be capable of integrating Phasor Measurement Units and associated applications relevant to <customer> power system dynamics context.The purpose of the WAMS shall be to take advantage of the latest technologies to address the new issues related to the interconnected <customer> electrical network including: Assessment and detection of instability/oscillation risks associated to long interconnection lines

between regions, Fast detection of islanding situations, and islands resynchronization after grid separation Analysis of any specific Power System dynamics issues not visible via traditional SCADA

measurement techniques

Voltage and angle measurements from PMUs shall also be made available to the SCADA subsystem via industry standard protocol IEC 60870-5-104 and used to improve the quality of the State Estimation solution.

The WAMS shall be based on a dual redundant hardware configuration and include: the acquisition subsystem the PMU data storage and monitoring subsystem applications for advanced analysis [an interface to the Advanced Monitoring and Visualization tool exporting key WAMS data and

alerts for Situation Awareness]i

1.2 PMU devices and communication facilities

The Contractor shall make the provision and installation of the priority PMU devices. When extensions of Telecommunications backbone facilities are required to connect the PMUs, these shall be <customer> responsibility.

1.3 Hardware configuration

The system shall run on a separate pair of servers, these will both normally run as a redundant (high availability) system, any configuration changes made to the master will automatically be propagated to the slave server. If a server should fail, the remaining server will continue operation; on recovery, the failed server will recover all lost data and configuration changes from the survivor. iiThese servers shall comply with the requirements expressed in the IT Infrastructure section for the servers of the Control Center Hardware configuration.

The access to the WAMS User Interface shall be properly protected in accordance with IEC/ISO 27002: Individual user logons (logged for security) with password protection Password protected privilege groups (e.g. for providing password protection for alarm threshold

settings)

i Delete bracketed text if e-terravision is not a targeted deliverableii The high availability option increases the system price by aprox 50%. If budget is an issue, then omit high availability but include in the specification an option to upgrade to the high availability as described

User login and data deletions shall be logged

1.4 Acquisition subsystem

A central Phasor Data Concentrator PDC shall be provided to interface with PMUs in the substations. The PMU interface shall be compliant with IEEE C37.118-2005 standard.

The PDC shall have extension capabilities to accommodate extension of the PMU quantities. It shall be possible in the future to extend this central PDC with: A Central PDC interfacing to the WAMS server(s) Regional PDCs concentrating PMU data for the Central PDC Substation PDCs routing PMU data in the substation to the Regional PDCsWhen using this extended architecture, the system shall be expandable to support at least 5000 input phasors in the future.

The Acquisition Subsystem shall provide the following capabilities: accommodate incoming PMU data at all data rates defined in IEEE C37.118-2005 standard,

including sample rates of 50 or 60 samples/second support simultaneously multi-vendor PMU’s, with proven capability to work with at least 5

different PMU vendor’s devices proven capability to accept multi-bus, multi-circuit PMU’s (e.g. 6 voltage phasors and 18

current phasors) assign individual phasor measurements either as sets of 3-phase inputs (in an order defined by

the user), or as positive sequence values. For example, a PMU measuring three current inputs shall be used either to measure all three phases in a single circuit, or to measure three separate circuits (assuming balanced phase)

ability for incoming phasors to be inverted or re-scaled individually, to aid recovery from misconnection of CTs or VTs

read symmetrical components from IEEE C37.118-2005 data streams and also calculate symmetrical components from three phase data

producing output data streams in IEEE C37.118-2005 format for hierarchical PDC operation. The administrator shall have full flexibility to specify any measured value to be included in (or excluded from) the output stream, and to define the output data rate. If the data is down-sampled, it shall be pre-filtered to avoid aliasing

tools to help setup configuration for roll-out of large numbers of PMU’s, including storage of configuration settings, PMU and alarm configuration cloning

1.5 PMU monitoring and data storage

The Data Storage function shall provide the following capabilities: the data storage capability shall not be limited by the design but subject to size of hard disk(s)

only. The provided disks shall host 5 years of PMU dataiii.

iii In general other vendors storage methods are less efficient so long storage times will give PhasorPoint an advantage provided HDD requirement are not unrealistic, as a rule of thumb a PMU monitoring a single line (6 Phasors : V1,V2,V3, Ia,Ib,Ic, + F, df/dt) will require 5GB/Month. 1-4 TB of RAID V Hard Disk Array is a realistic configuration for a small WAMS server. 15 months is often used as recommended minimum storage period since this allows examination of the previous year’s seasonal data should there be an event. Use storage calculator or refer to Psymetrix before making recommendations for disk requiremnts

data storage shall be driven by automatic and manually triggered event. SQL access to database shall be provided to allow external applications to directly access

WAMS data using an ODBC compliant interface.

The Monitoring function shall provide the following capabilities: Topological overview display of phasor data and oscillation application data, with user defined

background image 3 tier hierarchy of views - Complete system, Regional and Substation view of phasor data and

oscillation application data Drill down from high level display to lower level detail (e.g. Regional to Substation) Flexible phasor groupings to support uncluttered overview displays Capability to calculate Active and Reactive Power (from V and I) and Power factor (cos Φ) Capability to calculate user defined quantities based on addition, subtraction, multiplication and

division of scalar and complex values and constants Ability to define Alarms on monitored data Ability to save and restore alarm configuration settings Ability to view, sort and filter event logs for alarm and systems events

The system shall be self-monitoring, and provide the capability to raise alarms and gather statistics on the following: loss of GPS clock accuracy packet Loss disconnection of PMU

WAMS Alarms shall be interfaced to the EMS using IEC 60870-5-104iv.

1.6 User Interface

A map view of the <customer> area shall be provided, for both localized regions and the entire system. Intuitive navigation and drill down capability into the measurement level and the application results shall be provided.

A graphical representation of voltages angle and magnitude shall be provided for real time monitoring, together with any defined angle differences. [It shall be possible to replay geographical representations of historic events by selecting a period of time, then use playback, fast forward, pause, rewind etc, or to manually find a specific time by dragging a timebar]v

When necessary screens updates shall occur at least 10 times per second in order to visualise with smooth motion the rapid changes that can be observed thanks to the PMUs, during events like system separations.

Live strip charts shall be provided.

1.7 Advanced Applications

1.7.1 Advanced calculations and Alarming

iv Omit if the customer has a preference for another standard (e.g. ICCP) at present we only support 104v This functionality is presently available for MPP screens and is demonstrated in the videos. It will not be generally available for other screens until Summer 2012, if deployment is to be before this date delete bracketed section

PMU measurements shall be usable in complex calculations such as the calculation of line parameters from PMU measurements at both ends of a transmission line, resulting for example in the dynamic rating of line thermal capacity.

Advanced alarms shall be used to identify high-level warnings of wider system threats, taking advantage of the synchronisation of PMU data. This facility shall be applicable to wide-area system events such as the incipient conditions of a potential voltage collapse.

It shall be possible to configure User definable composite alarm events to operate on any logical combination of limit violations based on PMU data and calculated resultsvi. As an example, it shall be possible to build calculation of flexible wide-area alarms arising from several simultaneous geographically separate observations, including: low- or high-level measurements high positive or negative rate of change over a user-defined period application results such as oscillation damping and amplitude

Hysteresis shall be applied to alarms to avoid spurious events or premature clearing of the event.

1.7.2 Management of Power System Separation

This application shall be designed to alarm on system separations and provide real time tools to support management of islanding, re-synchronisation and blackstarts. It shall include the following features: event & alarm triggering on detection of system separation intuitive, geographical display of islanding conditions, based on frequency and relative rotation

of voltage vectors representation of relative voltage angle to show partial reconnections short term historic display of minimum and maximum frequencies

1.7.3 Oscillatory Stability Management

The Contractor shall deliver a field proven Oscillatory Stability Management (OSM) application for the management of governor (0.01-0.1Hz ) and electro-mechanical (0.1- 4Hz) modes of oscillation. A list of references operational in the field shall be attached to the offer. The OSM application shall be capable of: Oscillatory analysis on active power, system frequency and phase angle difference Fast analysis of power system dynamics for operational alerts and alarms Analysis of power system dynamics for system testing and long-term review Simultaneous detection of multiple modes of oscillation (with a minimum of 7 user specified

mode bands) Real-time mode shape analysis and display Mode frequency histograms over user defined time periods Real-time locus plots for each mode band (mode amplitude vs mode decay time)vii

Flexible alarming on mode frequency, amplitude and decay time, including o User defined exclusion areaso User defined on and off hysteresis settings

vi Composite alarms are a powerful differentiator and easily demonstrated with the video “Comp Alarm Video V Stab.avi”vii Alstom hold patents for this method

Identify if an area is contributing to an oscillatory mode, when PMUs are installed on all circuits bounding the area

Show the relative contribution to a specific oscillatory mode of any generator equipped with PMU(s)

Show the power flows connected with each separate mode of oscillationviii

1.8 Interface to SCADA and AMV

Key WAMS application results and alerts shall be available in the Advanced Monitoring and Visualization tool for Situation Awareness.

The WAMS data to be made available include: Voltage angle and amplitude to be used by the State Estimator, at a rate compatible with the

SCADA requirements; the IEC 60870-5.104 protocol shall be used to send PMU data to the SCADA for this purpose

Alerts detected by PMUs Application results such as oscillation mode frequency, amplitude and decay time.

Please read AND DELETE these notes

viii This and the two previous requirements relate to Mode Power Path (MPP) Alstom hold patents for this method

Note: PhasorPoint does not include any specific tools for the calculation of voltage stability margin (i.e. P-V “nose” curve or Thevenin methods) this is because these methods do not provide a reliable indication of voltage margin and are vulnerable to changes to generation excitation levels that can suddenly change the curve and thereby the margin levels available. ABB, Siemens and SEL recommend these methods and it is important to avoid voltage stability margin tools in a specification since our response will be weak. Reference can be made to a paper by Daniel Karlson (formerly ABB) where he explains why this method should not be used.