无限大容量供电系统三相短路电流分析

Analysis of Three-phase Short Circuit Current of Infinite-capacity Power Supply System

通过对无限大容量供电系统三相短路过程的分析,发现在三相短路过程中,其短路电流由周期分量和非周期分量组成.正是由于非周期分量的出现,才使电感中电流在突然短路瞬间前后不会突变.由于非周期分量的存在,在暂态过程中短路全电流曲线不与时间轴对称,以致短路后将出现比短路电流周期分量幅值更大的冲击电流.

Through the analysis of three-phase short circuit of infinite-capacity power supply system, we find out the short-circuit current is made up by the periodic component ip and non-periodic component i^p. It is because of non-periodic component, the current in the inductor will not be changed instantly in a sudden short-circuit. Because the existence of non-periodic component, the full current curve of short-circuit and time axis is not symmetrical in the transient process. This will lead to the instantaneous maximum amplitude value more than the periodic component of short-circuit.