基于最小基本回路集合的潮流转移快速搜索

Fast Search of Power Flow Transfers Based on Minimal Basic Circuit Set

由于过载线路切除潮流转移造成连锁跳闸的重大停电事故时有发生,为了阻止连锁跳闸,实时紧急控制非常必要,而过载线路切除后是否会形成新的连锁跳闸的估计算法的快速性、准确性成为关键。文中根据系统正常运行时的网络拓扑结构、元件参数和潮流状态在线得到基本回路—边关联矩阵、最小基本回路集合。线路过载后,在包含过载线路的最小基本回路及其环和运算后回路中实时搜索与其潮流方向相反的线路,采用直流分布系数法寻找过载线路切除后潮流增幅较大的线路,快速判断是否出现连锁跳闸。

Power system blackout after power flow transfers caused by overloaded line tripping often occurs.To avoid cascading tripping,real-time emergency control is necessary.The key issue is to predict whether there are new overloaded lines in the system effectively and accurately.The paper firstly forms the system＇s minimal basic circuit set using graph theory on-line based on network topology analysis,together with component parameters and system operation state.Secondly,after a line is overloaded,it obtains circuit containing the overloaded line,searches for the lines which have the opposite power flow direction to the overloaded line in the circuit,and extends the search range using ring sum operation.Finally,it calculates in series power flow of a line after the overloaded line trips using distribution factors to confirm the lines to whom most of the power flow of the tripped line has been transferred.As a result,the computational needs for further analysis and system security assessment can be significantly reduced.