交流串入直流电源系统正极或负极对继电器的动作影响分析

Analysis on Relay Action Caused by AC-DC Interference to Positive or Negative Pole of DC System

交流串扰直流系统可能会引起保护误动,尚缺乏完整的理论和仿真分析模型。建立了交流串入直流系统正极、负极的数学模型与仿真模型。通过对比数学公式计算、MATLAB仿真、实际试验结果,验证了理论分析与仿真模型的正确。分析和实验均证明了交流串扰直流系统正、负极两种情况下,继电器线圈两端的电压与二次电缆分布电容、交流串扰电源正相关,与限流电阻负相关。并提出了提高继电器动作功率、减小二次电缆分布电容、采用合适限流电阻、定期检查跳闸回路对地电容等防止交流串扰直流引起保护误动的措施。

AC-DC Interference can cause relay protection misoperation,it is still lack of workable theory and digital simulation models.In this paper,a theory analysis and digital simulation models of AC-DC Interference are proposed. The theory analysis and simulation models are proved correctly by experiment evaluation. The capacitance of cable to ground,resistance for current limit and AC interference voltage are the major factors to affect the voltage between the relay terminals. Finally,proposals of improving the relay action power,reducing the capacitance of cable to ground,choosing a reasonable resistance for current limit and checking the capacitance to ground regularly are presented.