Abstract:This paper through parallel operation of double lines one circuit transient fault protection device tripping reclosing the stability control device is operated machine case, analyzed the reason of 110kV parallel operation of double circuit line protection device in the distance of III segment movement time, reclosing time and 110kV power stability control device and cutting machine movement time mismatch the basic principles of cooperation between the three are summarized; according to the actual situation of the power system, put forward by optimizing the 110kV line protection distance III segment movement time, on both sides of the line reclosing time and to ensure the stability control devices and cutting machine with time solutions, in order to avoid similar incidents before repeated line transient fault reclosing the first movement stability control device and cutting machine, to ensure the reliability and continuity of power generating units, eliminate the parallel operation of double 110kV The adverse effects of the time fixed value mismatch between the circuit protection device and the stability control device of the 110kV power station.