The Research And Analysis On Out-Of-Step Separation Of Large-Scale Interconnected Power System

Large-scale interconnected power systems have become the trend of power systems development over states or wide, the security and stability problems also come up increasingly. Out-of-step separation emergency control for preventing accidents to expand up to widespread blackout in complex fault situations (i.e., breaking off out-of-step state, preventing voltage and frequency collapse and so on) is the third line of defiance, and is playing the very important role in power systems at home. It is an effective measure to split the power system to several small islands at appropriate time and proper spots to ensure the stabilization of each subsystem. The principle of the out-of-step separation equipment should have the function such as exactly start-upping the out-of-step separation equipment, exactly calculating the out-of-step period and capturing out-of-step center, and should fast and accurately capture the out-of-step section, and should implement the rational and designed separation, What for is to prevent accidents to expand up to widespread blackout and ensure the stabilization of power system.The mine task of this paper is such as: the change state of each electrical data for asynchronous operation are analyzed based on equivalent two-machion power system, which are simulated by MATLAB programming language, at the same time the change state of each electrical data for asynchronous operation are analyzed based on equivalent three-machion power system; center of out-of-step, oscillation center and their drift are analyzed and simulated for asynchronous operation tie-line based on the theories foundation of the second chapter, and out-of-step criterion is afford; the new out-of-step separation criterion is proposed, which is the weighted maximum of oscillation current as initial criterion and the voltage phase difference of angle based on PMU as main criterion, improving the security and the stability of the out-of-step separation equipment, and the feasibility is proved by emluating the testing system.