A Study on Taiwan Power Defense System

Abstract
This dissertation proposes a phasor measurement units (PMUs) based power defense system to prevent power system blackout due to a cascading relay trip events..
The power defense system uses PMU’s to monitor the generators and the major EHV transmission lines of a power system, and apply an instability prediction algorithm for initiating the remedial control actions to avoid a sequence of relay trip events whenever necessary. When a fault happens, the power defense system group the generators swinging coherently and reduce the system to One-Machine-Infinite-Bus (OMIB) system equivalent. Then using real-time phasor measurements estimates the parameters of OMIB. The strategy for determining the timing and amount of remedial control actions is a proposed relay setting limited equal-area criterion for OMIB. The remedial control actions consist of load shedding and generation tripping.
The proposed scheme is tested with Taiwan power system, which experienced a severe fault at a major EHV and caused a successive relay trips resulting in system north and center area blackout on July 29,1999(729-event). According to the computer simulation results, if the Taiwan power system had implemented the power defense system then the blackout of 729-event could be avoided.