Phasor Measurement Units (PMUs) and Time Synchronization

Phasor Measurement Units (PMUs) and Time Synchronization at European Utilities

Roel de Vries, MSc EE 16th of January 2013, AGH Krakow

Contents • Phasor Measurement Units (PMU) • Wide Area Measurement System (WAMS) • Commercial Installations • Captured events • Time Synchronization

Phasor Measurement Units (PMUs)

Phasor Measurement Units (PMUs) History of PMUs • • • • • • •

Invented in 1988 at Virginia Tech 1st Commercial PMU in 1992 1st Synchrophasor standard: IEEE1344 (1995) Updated in 2001: IEEE1344-2001 Big boost after 2003 US blackout Standard updated in 2005: C37.118-2005 Standard again updated in 2011: • C37.118.1 – Measurement specifications • C37.118.2 – Communications specifications

Phasor Measurement Units (PMUs) What is a PMU? • Time Synchronized (GPS) measuring device: • 3 Phase Voltage • 3 Phase Current

• Reporting following information: • • • • •

Voltage Magnitude & Angle (Phasor) Current Magnitude & Angle (Phasor) Frequency (deviation from nominal in mHz) Rate-of-change of frequency (ROCOF in Hz/s) Analog user defined data (e.g. sampled control signal or transducer value) • Digital user defined data (e.g. status or flag)

Phasor Measurement Units (PMUs) PMU Classes (C37.118.1) • 2 Classes: – M Class & P Class

• Protection Class: fast response, no filtering required • Measurement Class: higher accuracy, filtering of aliased signals, slower response • User choses what class might be useful for what application

Phasor Measurement Units (PMUs) Steady-state requirements • Phasor requirements over a specific • • • • •

Frequency range Voltage magnitude range Current magnitude range Phase angle range THD range

ALL MEASUREMENTS NEED TO BE WITHIN 1% TVE (Total Vector Error)

Phasor Measurement Units (PMUs) Dynamic requirements: Modulation • Phasor measurements starting at 100% rated signal magnitude and nominal frequency • Modulating according to specified signals over a certain frequency range


Phasor Measurement Units (PMUs) Dynamic requirements: Frequency Ramp • Phasor measurements starting at 100% rated signal magnitude and nominal frequency • Frequency ramp of 1.0 Hz/s


Phasor Measurement Units (PMUs) Dynamic requirements: Step Change • Phasor measurements starting at 100% rated signal magnitude and nominal frequency • Modulating according to specified signals over a certain frequency range


Phasor Measurement Units (PMUs) TVE Example • Measurement error steady state allowed: 1% TVE

Source: F. Steinhauser, Omicron

Wide Area Measurement System (WAMS)


Implementation in Europe • 100+ PMUs installed and around 60 in daily operational use • First Wide Area Monitoring System (WAMS) @ SwissGrid in Laufenburg, CH (12 years ago) • Many pilot projects • Some fully operational systems • No automatic control



Applications • Real time data analysis • • • • •

• • • • • •

Low freq oscillation detection Phase angle difference detection Voltage stability detection Islanding detection Oscillation source detection

Post mortem analysis Re-connection after Islanding Update state estimator (dynamically) Monitor line load Automatic load balancing Prove valuable input for dynamic system model


The Future of WAMS • IEEE and IEC working together in a Joint Synchrophasor Performance standard • Implementation of latest C37.118.1/2 standard in commercial equipment • New Applications! •

Automatic Control of grid operation?

Commercial Installations

Commercial Installations - Amprion • Year of installation: 2009 • Amount of PMUs: 11 • WAMS software: ELPROS WAProtector

– Cyclic 14 days database (full resolution, 50 frames/s) – Event database – Oscillographic database

• Applications: 1.

2. 3. 4.

Real-time analysis

a. b. c. d.

Phase angle difference monitoring Low-frequency oscillation detection Voltage instability detection Over/under value detection (Voltage/Current/Freq/Etc.)

a. b.

With other TSOs With SCADA/EMS system

Real time data exchange Power flow calculations Post-mortem analysis

Reference: Phasor Measurement Applications at Amprion Carsten Jahnke

Commercial Installations - Amprion

Reference: Phasor Measurement Applications at Amprion Carsten Jahnke

Commercial installations - elering • • •

Year of installation: 2010 Amount of PMUs: 14 WAMS software: ELPROS WAProtector

•

Applications:

– Cyclic 14 days database (full resolution, 50 frames/s) – Event database (10 000 records) – Oscillographic database

1.

2. 3. 4. 5.

Real-time analysis

a. b. c. d.


a. b.


Real time data exchange

Improve state estimator (development in progress) Improve system dynamical model (development in progress) Post-mortem analysis

Reference: Estonian WAMS System – Implementation and Experiences Jako Kilter, Alexei N. Goloshchapov, Bojan Mahkovec (Russian Cigre conference 2011)

Commercial installations - elering

Reference: Estonian WAMS System – Implementation and Experiences Jako Kilter, Alexei N. Goloshchapov, Bojan Mahkovec (Russian Cigre conference 2011)

Commercial installations - ELES • Year of installation: 2005 • Amount of PMUs: 20+ • WAMS software: ELPROS WAProtector

– Cyclic 14 days database (full resolution, 50 frames/s) – Event database – Oscillographic database

• Applications: 1.

2. 3. 4.

Real-time analysis

a. b. c. d.


a. b.


Real time data exchange

Initial test of new and refurbished generators (with Mobile PMU) Post-mortem analysis

Reference: Wide Area Measurement System in Action (PowerTech ‘07, Lausanne) T. Babnik, Member, IEEE, U. Gabrijel, B. Mahkovec, M. Perko, and G. Sitar

Commercial installations - ELES

Reference: Wide Area Measurement System in Action (PowerTech 07, Lausanne) T. Babnik, Member, IEEE, U. Gabrijel, B. Mahkovec, M. Perko, and G. Sitar

Captured Events

Captured Events – Low frequency Voltage and Frequency oscillation

Captured Events – Voltage angle difference Oscillation

Captured Events – Synching Turkish power system to ENTSO-E

Captured Events – Tie line reconnection

Time Synchronization

Time Synchronization GPS Clocks • • • • • •

GPS Clock ≠ GPS Receiver 1 input: C/A Code @ L1 freq. 1575,42 MHz Various outputs possible Internal deterministic conversion Some calculations to determine accurate time Accuracy ranging from 40ns – 1000ns typically

Time Synchronization

Time Synchronization Distribution Standards/Protocols • NTP/SNTP (Ethernet) • IEEE 1588 Precision timing protocol (PTP) (mostly Ethernet) • IRIG-B • PPS • Various ASCII serial strings

Time Synchronization Applications • • • • •

PMU Synchronization Event reconstruction Multi-Rate billing Traveling wave fault detection General IED synchronization

Time Synchronization Future Development • IEEE C37.238 available • Power profile “within” IEEE 1588v2

• IEEE 1588 will be updated • GLONASS • GALILEO • COMPASS

Thank you! Questions? [email protected]