一起由配电网合解环操作引起的出线开关跳闸分析

Analysis of Line Breaker Trip Caused by Loop Closing and Breaking Operation for Distribution Network

配电网合环时产生过大的电流造成电流保护动作是导致配电网合环失败的主要原因。分析了一起因合环电流大而导致跨多电压等级电网合环操作失败的实例,建立了合理的配电网合环模型,得出了合环稳态环流的计算方法,分析了合环暂态衰减的过程。找出了导致合环失败的关键原因不是两侧电压差,而是合环线路潮流大小与环状内主变变比、变压器阻抗值大小、主变负荷潮流以及环状线路阻抗、线路负载情况,并给出了提高合解环成功率的措施。

The main reason for the loop closing failure of distribution network is the overcurrent causes current protection action during the loop closing of distribution network. Firstly,a multi-voltage loop closing operation failed example due to the large closing loop surge current is analyzed. It establishes the reasonable model of the closed loop of distribution network. It obtains the calculation method of the steady loop current and analyses the transient process of decay. It is found that the key reason for the loop closing failure is not the voltage difference on both sides,but the ratio of transformation between the closing loop power flow and ring generator transformer,the transformer impedance value,the main transformer load flow and loop circuit impedance,and line load condition. Finally,the measures to improve the success rate of loop closing and breaking operation is proposed.