Wide Area Monitoring with Phasor Measurement Data

Wide Area Monitoring with Phasor Measurement Data Dr. Markus Wache Siemens E D EA, Nuremberg, Germany

Content Content Basics of Phasor Measurement Realization of PMUs Power System Stability Standard IEEE C37.118 Structure of Wide Area Monitoring System Application and references of WAM Summary Page 2 March 2010

SIGUARD Phasor Data Processor Why should we measure phasors? X s U 1 U 2 P2 = sin( δ ) Xs U 1 U 2 This equation means that active power flow is proportional to the phase angle difference between U 1 and U 2. Thus it is possible to measure power flow without complicated algorithms as state estimator, power flow etc. Page 3 March 2010

PMU Calculation of Total Vector Error Both amplitude and phase have to be considered for synchrophasor accuracy. angle error Page 4 March 2010

Influence of CT accuracy on TVE TVE = Abs Value of Vdiff CT accuracy is defined in IEC 60044-1 CT 0,5S: Angle error ϕ = max 0,5 deg Amplitude error = max 0,5% Abs(Vdiff) = 0,010038 TVE = 1% CT 10P Angle error ϕ = max 3 deg Amplitude error = max 3% Abs(Vdiff) = 0,05234 TVE > 5% CT 5P Angle error ϕ = max 1 deg Amplitude error = max. 1% Abs(Vdiff) = 0,02004 TVE = 2% Conclusion: To fulfill TVE requirements of standard measurement current transducer should be used. IEEE C37.118, Page 5 March 2010

SIGUARD Phasor Data Processor How to measure phasors GPS Signal IEEE C37.118 V, I, f, df dt Page 6 March 2010 Requirement time accuracy: at 60Hz: 1ms means 21,7! required: < 10μs GPS-Sync. necessary

Realization types of PMUs Currently, three different realizations of PMUs are offered: 1) Standalone PMU Mainly based on protection relay technology 2) PMU functionality integrated in fault recorders reasonable for transmission systems 3) PMU functionality integrated in protection devices reasonable for distribution systems Page 8 March 2010

Why Phasor Measurement Units? V 1 V 2 Loss of Synchronization Heavy Load Local Oscillations Reactive power shortage Line Trip Inter - Area Oscillations V Voltage collapse Transmission corridor congestion Cascading outages Frequency deviation f Loss of Generation P t Page 10 March 2010

Overview: Power System Security and Blackout Prevention Monitoring Fault Records Fault Protocols Results Operat. Instructions WAPC Met. Values WAMS Results Operat. Instructions Operator-Training Met. Values Results Expertsystem Expertsystem IAP SiGuard Measuring Analysis, Location SIMEAS SAFIR Metered Values of Relays / Recoders 1-100ms Page 11 March 2010 Phasor Data Processing System Evaluation locally IEEE C37.118, 2006 Metered Values of PMUs 20ms-200ms Scalable Acc. to no. Of PMUs Predicting DSA PSS TM NETOMAC PSA PSS TM SINCAL 1-5sec State estimator Short-Circuit Loadflow Contingency... Metered Values of Transducers Signal- Transmission Steps Relay Settings Switching State

PMU The standard IEEE C37.118 At present, IEEE C37.118 is worldwide the only standard in electric energy systems for the measurement of synchrophasors. Specifications for the measurement and assignment of synchrophasors: Time reference= UTC (Universal Time Coordinated) Angle reference = cos (0 if maximum at PPS-puls) Reporting rate = 10Hz or 25Hz for nominal frequenzy 50Hz Measuring error max. 1% TVE (Total Vector Error) Communication model (structure of telegramms) No specification for: Speed of measuring Measuring accuracy under transient conditions Hardware / software of meter Algorithm of measuring The fixed specifications make a simple processing of synchrophasors systems possible, both in real time and offline. of different measuring Page 13 March 2010

PMU The standard IEEE C37.118 Future development of the standard Dynamic requirements for measuring in PMU Harmonization with IEC61850 Page 14 March 2010

Possible structure of Wide Area Monitoring System (1/2) 1) Decentralized Structure One PDC in each substation Central PDC at Control Center Control Center Level PDC SCADA Pro: Local PDC as data storage in case of telecomm. Fault Con: Recall of information after telecomm.fault is not standardized proprietary solutions only Only few PMUs per substation (mostly one is sufficient) High amount of PDCs required PDC PDC PMU1 PMU2 PMU1 Substation 1 Substation 2 Page 16 March 2010 PDC. PMU1 PMU2 Substation n

Possible structure of Wide Area Monitoring System (2/2) 2) Centralized Structure PDC on control center level only Regional control center may have own PDC Pro: Better balance betwen number of PDCs and number of PMUs Less Costs Flexible Concept: PDCs to be placed where Phasor information is needed PDC Main Control Center Con: No storage for below lowest telecomm. fault PDC PDC Regional Control Center Remark: Local fault recorder functionality may serve as independent archive. PMU1 PMU2 PMU1 Substation 1 Substation 2 Page 17 March 2010. PMU1 PMU2 Substation n

Interfaces of a Wide Area Phasor Measurement System SCADA Phase Angle, Voltage, Frequency, Alarms State Estimation DISPLAY Phase Angle, Stability Analysis, Monitoring CONTROL Real Time Controls WACS PROTECTION Protection Schemes WAPS Phasor Data Applications Phasor Data Concentrator (PDC), System Monitor (PMU Errors, Communications, PDC Operations) Data Collection PDC IEEE C37.118 IEEE C37.118 IEEE C37.118 Scope of SIGUARD Phasor Data Processing System PMU PMU PMU PMU PMU Substation Measurements Page 18 March 2010

Application of Wide Area Monitoring Support analysis of critical system status by control center experts During disturbance: Fast and precise measurement display After disturbance: Use PMU measurements to understand the dynamic behaviour of the system to be able to improve it; create report. Load monitoring (stress) of lines based on angle differences Synchrophasors give a clear picture without the need of using system topology data Reference Phasor provides the view for the relevant difference Clear indication of system separation Example disturbance Nov 4th 2006, Europe: System separation was not recognised by all TSOs immediately Optimal loading of transmission corridors with Voltage-Power-Curve Gives an actual picture of load situation and reserves Check results of state estimation with real measurements Page 20 March 2010

Future applications Synchrophasors as base for Wide Area Control System Control of HVDC, FACTS as fast reaction to power swings based on synchrophasor measurement Algorithms will have a strong project specific component Synchrophasors as base for Wide Area Protection System Direct transmission of phasors between protection devices Could improve reaction of protection device PDC will probably not be involved Page 21 March 2010

Reference: transpower stromübertragungs (former E.ON Netz TSO), Germany gmbh (TPS) Description: 7 SIMEAS-R PMUs on 400kV Level in all parts of TPS-grid in Germany One central SIGUARD PDP Monitoring system in Bayreuth PMU-data sent via existing fast communication network from transpower Running in a test-configuration since March 2009 Reporting rate 10/s, nominal frequency = 50 Hz Page 22 March 2010

Reference: transpower stromübertragungs (former E.ON Netz TSO), Germany gmbh (TPS) Experiences: Several power swings could be observed in real time with damping and frequency Monitoring of change of power flow, caused by wind power infeed, in real time without using any topology information. Changing phase angles between different parts of the grid could be observed. Page 23 March 2010

Reference: transpower stromübertragungs (former E.ON Netz TSO), Germany gmbh (TPS) Example: Generation loss in southern europe Frequency PMU North PMU South Voltage PMU North PMU South Page 24 March 2010

Reference: transpower stromübertragungs (former E.ON Netz TSO), Germany gmbh (TPS) Example: Strong Windpower in the North Voltage Phasor PMU North1 PMU North 2 PMU South (reference) Phase Angle reaches 60 Degree Page 25 March 2010

Application: ewz (city supplier of Zurich), switzerland Description: 18 SIMEAS-R PMUs on distribution and transmission level in greater Zurich area One central SIGUARD PDP Monitoring system in ewz office PMU-data sent via existing fast communication network from ewz Running since May 2009 Reporting rate 25/s, nominal frequency = 50 Hz PDP server functionality to SAFIR (data aquisition tool) Goals: Fast Fault location in distribution network Synchrophasors used as additional information source for disturbance location Monitoring of the complete distribution network, especially at the interfaces to transmission network Experiences: PDP server functionality (sending out PMU data in IEEE C37.118 protocol) is implemented for the first time Page 26 March 2010

Wide Area Monitoring with Synchrophasors Summary Increased network load, thus it is necessary to understand the mid term dynamics (100ms 10s) by online observation and offline disturbance analysis of Voltage stability Frequency stability Power oscillations Loadability Phasor measurement is base technology for future smart grid features System integrity protection schemes (SIPS) Power oscillation damping devices (FACTS, fast valving) Real time state estimator Page 28 March 2010

Wide Area Monitoring with Synchrophasors Summary Using the complete capacity of transmission lines without loosing stability Transmission corridor supervision with nose curve (U-P-curve) Support for Blackout Prevention Fast Analysis of Power Swings Reports after disturbances can be quickly prepared Closes the gap between fast, local measurements (protection) and slow, large area measurements (control center) Page 29 March 2010

Thank you! Page 30 March 2010

Content Content Overview User Interface Application Roadmap Online Demo Page 31 March 2010

SIGUARD Phasor Data Processor Monitoring of - Online view or Power System Status Curve - Historic view (selectable) Geographical View (Google Earth based) Phasor diagrams Time charts Page 32 March 2010

SIGUARD Phasor Data Processor Voltage stability curve Calculation with Formulas Page 33 March 2010

SIGUARD Phasor Data Processor Online limit editing Measurement system health Page 34 March 2010

SIGUARD Phasor Data Processing System User Interface / Example Limits Editor Page 35 March 2010

Content Content Overview User Interface Application Roadmap Online Demo Page 36 March 2010

SIGUARD Phasor Application Data Processing System Phasor Data Concentrator: Collecting Phasor Measurement Data via IEEE C37.118 Protocol. PDP-Server: IEEE C37.118 Data Provider for other PDCs Monitoring - Online View or - View of history (selectable) - Phasor View or Time-based diagram Calculating and displaying of Status Value for the Power System Indication of measurement system health Geographical View (Google Earth based) Charts View and Measurement List (CSV-Export, configurable), for reporting Formula Editor for specific analysis Limits Editor for online adaptation of limits Transmission Corridor monitoring (Voltage-Power-Curve) Page 37 March 2010

Content Content Overview User Interface Application Roadmap Online Demo Page 38 March 2010

Thank you! Page 39 March 2010