不对称三相潮流的对称分量分析法

Unsymmetrical Three-Phase Load Flow Study Based on Symmetrical Component Theory

本文提出了在对称分量坐标中不对称三相潮流的两种求解方法——隐式阻抗矩阵法和解耦—补偿法。这两种方法都能充分利用对称分量坐标中对称元件,诸如发电机、变压器等的解耦特性,提高三相潮流的解算速度。解耦—补偿法则进一步利用不对称输电线路三序之间的弱耦合特性,通过对三序间弱耦合的补偿,实现三序之间的解耦求解,该法还适合于并行计算。算例表明,本文提出的方法具有较快的计算速度和良好的收敛特性。

For determining the unsymmetrical three-phase load flow, two methods based on symmetrical component theory-implicit Z-Bus Method and Decoupling-Compensation Method are proposed in this paper. By utilizing the sequence reference frame, such as those of generators and transformers, the Z-Bus method can obviously increase the speed of three-phase load flow computation without losing its accuracy. By further utilizing the weak coupling feature of unsymmetrical transmission line model in positive - negative- zero sequence reference frame, the decoupling-compensation method breaks the three-phase coupled model into three sequence-decoupled models with the injection of certain compensation currents into both terminal buses of the line, thus opens up a way to the utilization of parallel processing. The validity of these methods is verified by numerical examples.