电力系统是一个复杂的动态系统,在运行过程中,经常会发生故障。通过对电力系统常见的4种短路故障(三相短路、单相接地、两相短路、两相短路接地)进行了理论分析,然后使用Matlab/Simulink仿真软件建立了故障模型,并进行了仿真验证,得出了4种短路故障短路点的电压与电流波形及其对应的序分量波形。最后根据电力系统故障时短路点电压与电流的特点,研究了利用负序和零序分量的短路电流检测方法。研究表明,以负序分量为特征量的检测方法在4种短路故障情况下,反应时间最短,反应最明显。
Power system is a complex dynamic system and the fault often occurs in the running process.In this paper,four kinds of power system short-circuit faults which contain three-phase short circuit,singlephase to ground,the two-phase short circuit and two-phase short circuit to ground are analyzed.Then the fault model is built by using Matlab/Simulink simulation software and the voltage and current waveforms with its sequence waveforms of 4kinds of short circuit faults are plotted.At last,according to the characteristics of short-circuit point voltage and current in power system fault,the method for detecting the short circuit current with negative sequence and zero sequence components is studied.The study shows that the detection method based on negative sequence component has the shortest reaction time and is the most obvious in 4kinds of short circuit faults.