含分布式电源配电网通用故障电流计算方法

针对含分布式电源的配电网故障电流计算通用性差或计算量大的问题,提出一种通用、计算量小的故障电流计算方法。将分布式电源分为机组并网与逆变器并网两类激励源,考虑低电压穿越要求,给出分布式电源的故障特性。在此基础上,根据叠加定理,将线性故障配电网分为不同激励源作用下的两部分,对两类激励源作用下的配电网分别进行故障电流分量计算,叠加求得总故障电流。计算过程中,对逆变器并网激励源产生的故障电流分量采用迭代算法进行求解。编制了所提的算法程序,计算实际配电网的短路电流。计算结果表明,所提通用故障电流计算方法正确、有效。

A general fault current calculation method for distribution network with distributed generation

A general method of fault current calculation with reduced computation is proposed for distribution network with Distribution Generation (DG), with regard to the issue of poor generality or intensive computation in fault current calculation. The DGs are divided into two types, which are generator-connected and inverter-connected. Considering the low voltage traversal requirements, the fault characteristics of the DGs are calculated. On this basis, according to the superposition theorem, the linear fault distribution network is divided into two parts under different excitation sources. The fault currents of the distribution networks under two kinds of excitation sources are calculated respectively, and the total fault current is obtained by superposition. During the calculation process, the fault current component generated by inverter-connected excitation source is solved by iterative algorithm. The method is programmed and the actual example is solved. The calculation results show that the method is correct and effective. This work is Natural Science Basic Program of Shaanxi Province (No. 2015JM5211).