Adaptive Voltage Stability Protection Based on Load Identification Using Phasor Measurement Units

With the continuously increasing power demands, the power system is much closer to its limits. As a result, the power system is more vulnerable to disturbances and faults. The voltage instability is one of the main reasons of cascading trip, wide-area blackout, and even the system-wide voltage collapse. In this paper, the online load identification using measurement-based approach based on Phasor Measurement Units (PMU) was proposed to evaluate the proximity to voltage instability in order to prevent voltage collapse. In the scenarios of disturbances, the proximity to voltage collapse with respect to load characteristics was evaluated. Based on different load characteristics, different control and protection schemes were implemented, i.e. shunt capacitor connection, on-load tap changer blocking and load shedding. The results showed that load-based adaptive voltage control and protection scheme based on PMUs is promising, as it prevented the voltage collapse and minimized the load shedding area.