Phasor Measurement Units (PMUs) and Time Synchronization. Roel de Vries.
24th of March 2011, TUDelft. Page 2. Contents. Phasor Measurement Units.
Phasor Measurement Units (PMUs) and Time Synchronization Roel de Vries 24th of March 2011, TUDelft
Contents Phasor Measurement Units • • • • • •
History of PMUs What is a PMU? Accuracy of a PMU Applica6ons PMUs in Europe Future Development
Time Synchronization • • • •
GPS Clocks Standards/Protocols Applica6ons Development
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 replaced in 2005 by: C37.118-2005
Phasor Measurement Units (PMUs) What is a PMU? • GPS Time Synchronized 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
Phasor Measurement Units (PMUs) Accuracy of a PMU? • Measurement error allowed: 1% Total Vector Error
Source: F. Steinhauser, Omicron
Phasor Measurement Units (PMUs) 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 Improve state estimator Monitor line load Automatic load balancing
Phasor Measurement Units (PMUs)
Phasor Measurement Units (PMUs)
Phasor Measurement Units (PMUs)
Phasor Measurement Units (PMUs)
Phasor Measurement Units (PMUs) PMUs in Europe • Around 70 installed and operational • First Wide Area Monitoring System (WAMS) @ SwissGrid in Laufenburg, CH (10 years ago) • Many pilot projects • Some fully operational systems • No automatic control
Phasor Measurement Units (PMUs) Future Development • IEEE C37.118 undergoing revision: • C37.118.1 = Measurement part • C37.118.2 = Communications part
• Adding Dynamic requirements • Harmonization with IEC 61850 • Completion within a year? Or two? Or?
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 • • • • •
Time Synchronization Distribution Standards/Protocols • • • • •
NTP/SNTP IEEE 1588 Precision timing protocol (PTP) 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 under development • Power profile “within” IEEE 1588
• GLONASS • GALILEO • COMPASS
Thank you!
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