It is difficult to detect and extinguish direct current(DC)arc in power electronics systems,and the arc could easily lead to a fire and cause great damage to surrounding equipment.A DC arc generation simulation unit i...It is difficult to detect and extinguish direct current(DC)arc in power electronics systems,and the arc could easily lead to a fire and cause great damage to surrounding equipment.A DC arc generation simulation unit is established,in which DC series arcs are generated by dragging the moving electrode away from the fixed one with the help of the stepper motor.In addition,a ferrite rod antenna is used to receive the electromagnetic radiation signals induced by the arcs.Based on experiments using the unit,the general characteristics of DC arc,including the pulse characteristics of arc current and source output in corresponding time window,and the frequency-domain characteristics of arc current,are studied.With discussion on three detection methods,it is concluded that the variation of current and voltage of arc,the spectrum of the arc current during the discontinuous intervals and the radiating electromagnetic signal are all features that can be adopted for detecting DC series arc.Therefore,a synthetic judgment method is suggested for further study.展开更多
气体绝缘金属封闭输电线路(gas insulated metal enclosed transmission lines,GIL)在运输及安装过程中易遗留绝缘隐患,进而引发内部电弧故障。内部电弧故障的接地电流特性对GIL设备的绝缘诊断及故障定位工作具有重要应用价值。针对上...气体绝缘金属封闭输电线路(gas insulated metal enclosed transmission lines,GIL)在运输及安装过程中易遗留绝缘隐患,进而引发内部电弧故障。内部电弧故障的接地电流特性对GIL设备的绝缘诊断及故障定位工作具有重要应用价值。针对上述问题,该文提出了基于动态电弧理论的GIL仿真模型,并开展不同运行工况下的接地电流特性研究。研究通过Mayr-Schwarz电弧及Bergeron传输线理论,结合GIL设计参数,搭建了正常运行与内部电弧故障工况下的电磁暂态程序(electric magnetic transient program,EMTP)仿真模型,并对2种工况三相短接排的接地电流特性展开特性分析。结果表明,正常运行工况下的短接排将流过近似对称的三相工频电流,接地电流幅值不超过额定负载电流的1%。GIL内部发生电弧故障后,将产生沿GIL管廊两侧传播的故障电流行波,接地电流将在纳秒级时间内发生突变,并出现幅值可达7kA的微秒级故障暂态电流衰减过程。最后,基于真型GIL的模拟脉冲测试,验证了基于暂态电流法GIL故障定位方案的可行性。仿真结果可为GIL设备的绝缘设计及故障定位提供参考。展开更多
基金Project supported by International Cooperation Project in Shaanxi Province of China(2012KW-01)
文摘It is difficult to detect and extinguish direct current(DC)arc in power electronics systems,and the arc could easily lead to a fire and cause great damage to surrounding equipment.A DC arc generation simulation unit is established,in which DC series arcs are generated by dragging the moving electrode away from the fixed one with the help of the stepper motor.In addition,a ferrite rod antenna is used to receive the electromagnetic radiation signals induced by the arcs.Based on experiments using the unit,the general characteristics of DC arc,including the pulse characteristics of arc current and source output in corresponding time window,and the frequency-domain characteristics of arc current,are studied.With discussion on three detection methods,it is concluded that the variation of current and voltage of arc,the spectrum of the arc current during the discontinuous intervals and the radiating electromagnetic signal are all features that can be adopted for detecting DC series arc.Therefore,a synthetic judgment method is suggested for further study.
文摘气体绝缘金属封闭输电线路(gas insulated metal enclosed transmission lines,GIL)在运输及安装过程中易遗留绝缘隐患,进而引发内部电弧故障。内部电弧故障的接地电流特性对GIL设备的绝缘诊断及故障定位工作具有重要应用价值。针对上述问题,该文提出了基于动态电弧理论的GIL仿真模型,并开展不同运行工况下的接地电流特性研究。研究通过Mayr-Schwarz电弧及Bergeron传输线理论,结合GIL设计参数,搭建了正常运行与内部电弧故障工况下的电磁暂态程序(electric magnetic transient program,EMTP)仿真模型,并对2种工况三相短接排的接地电流特性展开特性分析。结果表明,正常运行工况下的短接排将流过近似对称的三相工频电流,接地电流幅值不超过额定负载电流的1%。GIL内部发生电弧故障后,将产生沿GIL管廊两侧传播的故障电流行波,接地电流将在纳秒级时间内发生突变,并出现幅值可达7kA的微秒级故障暂态电流衰减过程。最后,基于真型GIL的模拟脉冲测试,验证了基于暂态电流法GIL故障定位方案的可行性。仿真结果可为GIL设备的绝缘设计及故障定位提供参考。
