交流电源分励线圈用于接地保护的可行性研究

Feasibility Study of AC Power Shunt Coil Used in Grouding Protection

DL/T 5153―2014《火力发电厂厂用电设计技术规程》将火力发电厂中性点直接接地的低压厂用电系统装设单相接地保护的装设范围扩大为所有低压配电回路。本文采用ETAP仿真分析软件对不同容量变压器、不同截面电缆下单相短路电流大小及母线残压,证实了马达保护器或接地保护器跳220 V相地交流操作电源的分励线圈是可行的,且具有较好的经济性。对于电动机回路,推荐在全厂广泛采用该方案。

DL/T 5153―2014 Technical rule for designing auxiliary power system for fossil fuel power plant expands the application range of single-phase grounding protection for low-voltage power supply systems to all low-voltage circuits.In this paper,ETAP simulation analysis software is used to analyze the short-circuit current and bus residual voltage of single-phase grounding In different capacity transformers and different section cables.It is proved that it is feasible and economical for motor protector or ground protector to trip the shunt coil of 220 V phase to ground AC operation power.This scheme is widely recommended for motor circuits in the whole plant.