基于二次注入的配电网接地故障有源电压消弧方法

针对中性点非有效接地配电网中存在的单相接地故障消弧问题,提出了一种基于二次注入的配电网接地故障有源电压消弧方法。该方法通过向配电网中性点注入工频电流来达到单相接地故障消弧目的,确保电网安全稳定运行。注入电流的参考值由二次注入特定电流的方法得到,将注入电流偏差信号通过比例谐振控制器,驱动逆变器开关管产生逆变电流,经滤波电路后注入电网中性点,抑制故障点电压和电流到零。仿真及10kV接地故障实验表明,该方法响应速度快、灵敏度高,能补偿配电网接地故障电流的无功电流分量、有功电流分量及谐波分量,实现瞬时接地故障快速可靠灭弧。

Active arc-suppression method of grounding fault for distribution network based on secondary injection

To solve the problem of arc-suppression of single-phase grounding fault in neutral non-effectively grounded distribution network, an active arc-suppression method of grounding fault for distribution network based on secondary injection is proposed in this paper. By means of injecting current with power frequency into the neutral point of the network, the purpose of arc suppression of single-phase grounding fault can be achieved, which ensures the safe and stable operation of the power grid. The reference value of the injection current is obtained by injecting a specific current to the system twice. Injection current deviation signal is put into proportional resonant controller to drive inverter switch to generate inverter current. And then, the current is injected into the neutral point of grid through the filter circuit, which can suppress the fault voltage and current to zero. Simulation and 10 kV grounding fault experiments show that the method has fast response and high sensitivity, and can compensate the reactive current component, active current component and harmonic components of the grounding fault current, which realizes fast and reliable arc extinguishing of ground fault. This work is supported by Smart Grid Technology and Equipment Major Project in National Key Research and Development Program of China (No. 2016YFB0900600), Science and Technology Project of State Grid Corporation of China (No. 52094017000W and No. 52170217000S), and National Natural Science Foundation of China (No. 51425701 and No. 51737002) and Science and Technology Project of State Grid Hunan Electric Power Company Limited (No. 5216A01700AH).