Research Of Setting Way Of Undervoltage Load Shedding In Power System

With the development of social economy, power system has experienced fast development. The scale of power system continues to expand and the structure of the network is more complex. Environmental and economic factors' confinement have been stricter, all of this will bring serious challenges to power system and be easy to cause voltage collapse. Undervoltage load shedding (UVLS) is one of a simpler, lower cost and effective solutions to voltage collapse.The paper analyzed and summarized the research status of the UVLS, pointed out the crucial issues. It summed up various mechanization of voltage instability. It analyzed the reason of UVLS how to play a role. Some common setting of UVLS was been discussed, some existing research results was also summarized. A new method of site selection for UVLS based on voltage stability analysis of PSASP is proposed, using risk based voltage security assessment, much uncertainty factors was quantified and corresponding working conditions of error list was took into account, combined with participation factor calculated from PSASP and economic losses of load shedding, consequences was calculated. Site selection for UVLS is determined from risk order, this method was small workload and various conditions was took into account, it had good adaptability, by setting target range of voltage recovery, the amount of load which has to be shed during UVLS is optimized based on calculated sensitivity under various working conditions, the proposed algorithm is tested on IEEE 39-bus system, comparing with other group of amount of load which has to be shed, it can find that after optimization the effect index of voltage recovery is the least, the phenomenon of voltage curve vibrating and voltage suspending in a low value didn't occur, showing that this method is correct and effective.