基于新型故障电弧模型的电弧能量特性分析

Investigation on Fault Arc Energy under Different Load Based on the New Time Varying Resistance Fault Arc Model

建筑物低压配电系统中频繁发生的电气火灾现象主要由故障电弧引起。电气火灾发生的频率和严重程度与故障电弧释放能量的大小密切相关。为此,分析了故障电弧引起的电路特征变化,根据该特征建立了能描述发生故障时电弧电路动态变化特征的新型故障电弧时变电阻模型,利用该模型计算了不同负载情况下故障电弧的电压、电流。在此基础上,分析了不同负载条件下故障电弧能量特性,并讨论了故障电弧的能量与负载有功功率、功率因数的关系。研究结果表明,负载有功功率越大、功率因数越小,故障电弧释放的能量越大,越容易引发电气火灾,需要重点进行故障电弧检测与防治。

Electrical fire accidents frequently occurred in low voltage distribution systems of buildings are mainly caused by fault arc. The occurrence frequency and severity of electrical fires depend on energy generated by fault are. Based on dynamic variation characteristics of circuit, a new time-varying resistance model of fault arc is proposed. Furthermore, fault arc voltage and current under different loads are obtained by using proposed model. Changes of fault arc energy under different load are discussed; and the relationship between fault are energy and power factor is investigated. The resuhs show that fault arc energy increases with increasing of active power and decreasing of power factor, which associated with high possibility of electric fires.