串联直流电弧特性及其在故障诊断中的应用

直流电弧故障常常会威胁到各种电力电子系统的安全运行,由于其本身的随机性和不稳定性,直流电弧故障很难被有效地检测出来。笔者设计了一套串联直流电弧试验系统用以研究不同因素如负载电流、直流源电压以及电极间隙长度对直流电弧特性的影响。在试验中,负载电流在6~30 A之间变化,直流源电压在75~300 V之间变化。同时还进行了固定源电压和负载电流下不同间隙长度的试验以研究电弧长度对电弧特性的影响。根据以上试验结果,进行了初步的电弧电压—电流特性的研究。最后,通过对时间窗内电流变化率的分析,研究了电弧电流的脉冲模式。以上研究结果为直流电弧特性研究及直流电弧故障检测提供了重要的基础。

Series DC Arc Characteristic Study and the Application in Fault Recgnition

DC arc fault introduces major safety concerns in a wide variety of power electronic applications.However,the randomness and instability of DC arc makes it difficult to be detected.In this paper,an experimental system to study the characteristics of series DC arc was designed and different tests were conducted in order to determine the influence of different factors to the arc such as gap length,current,etc.During the experiments,the load current was varied from 6 A to 30 A and DC source voltage was changed from 75 V to 300 V.Also,DC arc fixed power supply voltage and load current but changing gap length were conducted to examine the influence of arc length.Based on the experimental results,a primary U-I characteristics study was carried out.Current variation analysis was performed to investigate the pulse patterns of the arc current for detection purposes.The results of this paper provided insights of the dc arc characteristics as well as methods for DC arc fault detection.