UBC Theses and Dissertations
Wide-area monitoring and control utilizing PMU measurements for a system protection scheme Palizban, Atefeh
The ever increasing complexity of the electrical grid has made it difficult to predict and anticipate contingencies. This is mainly due to the advent of deregulated electricity markets, aging transmission infrastructure and the growing penetration of renewable resources. The wave of blackouts in recent years has made utilities much more aware of the need for power system wide monitoring and control. One of the fundamental requirements to achieve that goal is to have common measurement reference. A few technology enablers have emerged which have led to development of a new kind of measurement paradigm; Phasor Measurement Units, or PMUs. PMUs bear high potential for wide-area system monitoring and control as well for conducting advanced engineering analysis. PMUs can provide time-synchronized high-resolution estimates of voltage and currents (both phase amplitude and angle) as well as frequency and rate of change of frequency. Such measurements, alternatively called synchrophasors, can provide visibility of a power system distributed over a wide geographical area and can be utilized in a multitude of applications including real-time monitoring, advanced power system protection, and advanced control schemes. In this thesis, a new special protection scheme (SPS) is proposed based on synchronized measurements provided by PMUs. An existing remedial action scheme (RAS) protecting for contingencies impacting the tie-line interconnecting the Alcan system to B.C. Hydro, using conventional relays is studied, and a new scheme based on time-synchronized, and high-resolution voltage angle measurements from PMU’s in a Wide-are monitoring system (WAMs) is proposed . In this new scheme, the angles of the buses at large power plants in both systems are examined and used to calculate various criteria based on region center of angle and the kinetic energy function to implement RAS. The results of a number of time domain simulations demonstrate that the proposed scheme can lead to faster operation of the SPS and decreased amount of generation and load shedding in the Alcan system. The achieved speed and efficiency of the proposed scheme in comparison to the existing installed scheme further highlight the opportunity in utilizing PMU measurements in online applications for power system protection and monitoring.
Item Citations and Data
Attribution 2.5 Canada