两回输电线路交叉跨越故障的短路电流计算方法

Short Circuit Current Calculation Method for Crossing Fault of Two Transmission Lines

随着输电线路的分布日益密集,两回输电线路在交叉跨越点处发生交叉跨越故障的可能性剧增,现有短路计算方法仅能处理多点复杂故障类型,无法处理同一交叉跨越位置多跨接点的复杂故障类型。为此,提出了一种含多跨接点的交叉跨越故障的短路电流计算方法。首先构建交叉跨越两回输电线路在故障点处的序网络方程,并建立含多跨接点复杂故障的通用故障拓扑,然后按相构建两回线路交叉跨越故障端口的故障边界条件方程,利用相序转换变换为各序网的故障边界条件方程,再联合序网络方程求解故障电流和电压。最后,利用PSCAD/EMTDC构建电网故障仿真模型,仿真结果验证了该方法的正确性。

With the increasingly dense distribution of transmission lines,the possibility of fault at the crossing point of two transmission lines is intensively increasing. The existing short circuit calculation can only deal with the complex fault types with multi-point while it is unable to deal with the complex fault at the same crossing position with multi-span points. Therefore,this paper presents a short circuit current calculation method for crossing fault types with multi-span points. Firstly the sequence network equations at the fault point of two crossing transmission lines are constructed,and a general fault topology for complex fault with multi-span points is established.Then,the fault boundary condition equations for crossing fault port of two transmission lines are constructed based on phases. The phase sequence transformation is used to convert the fault boundary condition equations for each order network,and the fault current and voltage are solved by jointing the sequence network equations. Finally,a fault simulation model of power network is constructed by PSCAD/EMTDC,and the results verify the correctness of the method.