含电感型故障限流器的煤矿电网短路暂态过程研究

Research on coalmine power grid short-circuit transient process with inductive type fault current limiter

煤矿电网中可以采用开关电路与限流电抗器并联组成的电感型故障限流器来限制短路电流。由于故障限流器直接参与了短路过程,使得供电系统短路过程更加复杂,短路电流将经历短路和限流两个暂态过程。通过对故障限流器结构进行研究,提出采用理想开关与电感并联的结构模型代替电感型故障限流器,对含电感型故障限流器的煤矿电网进行短路暂态过程分析,推导短路电流变化公式,分析故障限流器动作时间要求及限流器限流特性。MATLAB仿真及实例分析结果表明理论推导的正确性。

Current limiting reactor is widely used in coalmine power grid to limit shortcircuit current, but it has some side effects, such as large voltagedrop and energy consumption. In order to reduce its negative effects, a switching cir cuit can be used in parallel with current limiting reactor to form a structure of fault current limiter. Fault current limiter （FCL） can be used in coalmine power grid to limit short circuit current level, so it is directly involved in shortcircuit process,which makes system＇ s shortcircuit process more complex. Shortcircuit current in coalmine power grid with FCL will experience two transient processes：shortcircuit current process and current limiting process. By research on fault current limiter structure,this article proposed a structural model of ideal switch and inductor in parallel instead of inductive type fault current limiter;and analyzed short circuit transient process of coalmine power grid with inductive type fault current limiter and circuit parameter variation, then derived current changes formula, deduced required ac tion time of FCL and its currentlimiting characteristics. MATLAB simulation and case analysis results show the cor rectness of the theoretical derivation in this article.