Research On Improving The Reliability Of Relay Protection System In Suzhou Power Grid

As the first defence of power system protection,relay protection plays an important role in preventing failure and disturbance for power grid.It is an important part of power system and its normal work or not has a significant impact on the operation of power system,so how to improve the reliability of relay protection system has become more and more attention.In this paper,the development and trend of relay protection research was studied combined the researches at home and abroad and the characteristics of relay protection in different stages were analyzed.The reliability analysis method of relay protection device is summarized,including fault tree analysis and Markov state space method.Based on this,the reliability model of the new type microcomputer relay protection system combined with a variety of reliability indicators was established and important parameter(Availability)was calculated.The reliability of relay protection system of Suzhou power grid in 2015 was calculated and analyzed through the above mathematical model.Based on the reliability calculation of relay protection of power grid,a modified scheme is put forward and the retrofit effect is evaluated considering the former model.