直流系统故障选线和故障类型识别方法研究

REASEARCH OF FAULT LINE SELECTION AND FAULT TYPE RECOGNITION METHOD OF DC SYSTEM BASED ON GRAPH THEORY

直流系统故障后故障电流上升迅速且无过零点,为解决以上问题,提出基于图论的故障选线和故障类型识别方法。将整个配电网看成以线路汇聚点为顶点,以连接线为边的＂图＂,根据顶点之间电流方向形成网络拓扑矩阵＂D＂,根据D阵中的各个元素进行故障选线。同时提取di/dt故障特征量对故障是否发生进行进一步判断,避免了潮流反转导致的误判。为实现故障类型识别,引入＂双D法＂。最后,针对不同类型、不同拓扑结构下的故障,对方法进行有效性分析。

Fault current rises rapidly without zero-crossing after a DC system fault,in order to solve the problem,the fault line selection and fault type identification method are put forward.The whole distribution network is seen as ＂map＂ which line convergence point is for the vertex and the connection line is for the edge.The network topology matrix ＂D＂ is formed according to the direction of the current between the vertices,and the fault line is selected according to each element in the D array.At the same time,the di/dt fault feature amount is extracted to further judge whether the fault occurs or not,so as to avoid misjudgment caused by reversed power flow.The ＂Double D method＂ is introduced to realize fault type recognition.Finally,the effectiveness of the method is analyzed for faults of different types and different topology structures,