二次回路交流串扰继电器线圈对继电器动作的影响分析

Influence of Secondary Circuit AC Interference on Relay Action

交流串扰直流系统可能会引起保护误动,但对该问题尚缺乏完整的理论和仿真分析模型。为解决该问题,建立了交流串入继电器线圈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性。分析和试验均证明,在交流串扰继电器线圈情况下,继电器线圈两端的电压与直流电源、交流串扰电源正相关,与限流电阻、平衡桥电阻负相关,受直流系统电容影响不大,并提出了提高继电器动作功率、选择合适的平衡桥电阻、采用合适限流电阻等防止交流串扰直流引起保护误动的措施。

AC interference in DC system may cause protection error, but there is no complete theoretical and simulation model for this problem. Therefore, the mathematical model and simulation model for AC series with the relay coil are established. The correctness of theoretical analysis and simulation model is verified by comparison of mathematical formula, MATLAB simulation and actual test results. As the analysis and test results show, under the condition of AC interference in relay coil, relay coil ends＇ voltage is positively correlated to DC power and AC interference power; negatively correlated to the current limiting resistance and the balance bridge resistance; slightly affected by the DC system capacitance. Then it puts forward measures to prevent protection maloperation caused by AC-DC interference, including improving relay action power, choosing the appropriate balance bridge resistance, adopting appropriate current limiting resistance, etc.