Use of Synchronized Phasor measurement System for Enhancing AC-DC Power System Transmission Reliability and Capability

Abstract

This paper is discussing the use of Synchronized Phasor Measurement Technology, which is now being used for monitoring power system status and dynamic transient event recording at Southern California Edison (SCE). This system is expected to enhance AC-DC power transmission system reliability and capability by monitoring the phase angles and oscillations at several substations and two remote DC terminals. The system could be used for HVDC power modulation in future. SCE has been working aggressively on this Synchronized Phasor measurement technology for over eight years and obtains data from fourteen Phasor Measurement Units (PMUs) and the two Phasor Data Concentrators (PDC) on its system. The data from the PMUs is now being collected and being used for analysis of system disturbances. SCE also obtains the data from Bonneville Power Administration Grand Coulee generating substation, which is over 900 miles away, and close to the Northern HVDC Pacific Inter-tie terminal and monitors the phase angle between the north and the south HVDC Pacific Inter-tie terminals. SCE is continuing to work on this technology with Bonneville Power Administration (BPA) and Los Angeles Water and Power to investigate the possibility implementing it for real-time monitoring and control. SCE is also working with other Western Electric Coordinating Council (WECC) members for information exchange. It is believed that the technology has great potential for enhancing power system stability and power transmission system capability of an AC-DC inter-tie system. This technology is also being used for monitoring the system stability and resulting information can assist in avoiding major system disturbances like the one that occurred on August 10, 1996 in WECC and on August 14, 2003 in Northeast United States and Canada.