Use of synchronized phasor measurements for dynamic stability monitoring and model validation in ERCOT

This paper discusses experiences in the use of synchronized phasor measurement technology in Electric Reliability Council of Texas (ERCOT) interconnection, USA. Implementation of synchronized phasor measurement technology in the region is a collaborative effort involving ERCOT, ONCOR, AEP, SHARYLAND, EPG, CCET and UT-Arlington. As several phasor measurement units (PMU) have been installed in ERCOT grid in recent years, phasor data with the resolution of 30 samples per second is being used to monitor power system status and record system events. Post-event analyses using recorded phasor data have successfully verified ERCOT dynamic stability simulation studies. Real time monitoring software “RTDMS”® enables ERCOT to analyze small signal stability conditions by monitoring the phase angles and oscillations. The recorded phasor data also enables ERCOT to validate the existing dynamic models of conventional and/or wind generator. Several specific recorded events are discussed in this paper.