The Research Of Large Power System Out-of-step Separation

Huge power system connected over states or wide areas has become the trend of power system development, the security and stability problems come up increasingly.This research is based on the China Southern Power Grid (CSG) Security and Stability Control Project of NARI-RELAYS Electrical Co., Ltd. In this paper, firstly, serious faults under two important operation modes of CSG are simulated, and then the simulation result is analyzed in a program designed by myself, to find the oscillation center, and to see the influence on the stability of the electrical isolated islands after separation and the underfrequncy load shedding with different separation time. Based on the current arrangement of separation devices in CSG and their implementing criteria, the performance of the out-of-step separation devices when system is out-of-step is analyzed, and the suggested arrangement of separation devices and out-of-step separation scheme are proposed. The out-of-step devices coordination is also researched, and a rational remote communication scheme among each separation device is suggested after detailed analysis and comparation.During the out-of-step research of CSG, the exsisted theories and methods about out-of-step criterion, out-of-step interfaces capturing and separation time choosing are simulated and compared, and based on the study of especial problems appeared in CSG researching course, a new methord of large power system out-of-step analyzing by BPA is proposed, and the finally results of simulation proved that the method is correct and valid.