开关柜中电快速瞬变脉冲群耦合途径的研究及电磁隔离

Coupling paths of EFT/B in switch cabinet and electromagnetic shielding

为了抑制高压开关柜中的电快速瞬变脉冲群在微机保护装置的外壳上感应出骚扰电压和骚扰电流,在电磁场有限元仿真软件ANSOFT中根据开关柜的结构建立开关柜模型,分别仿真研究电快速瞬变脉冲群电压和电快速瞬变脉冲群电流形成的瞬态电磁场对微机保护装置外壳的耦合过程,并采取电磁屏蔽和空间隔离等措施切断其耦合途径。仿真结果表明,通过研究开关柜中电快速瞬变脉冲群的耦合过程而制定的电磁隔离措施可以有效减弱耦合到微机保护装置外壳的电快速瞬变脉冲群。

The voltage and current disturbances induced by EFT/B（Electrical Fast Transient/Burst） on the enclosure of microprocessor protection device in HV switch cabinet should be restrained. The switch cabinet model is built with the electromagnetic finite element software of ANSOFT according to its structure. The coupling process of transient electromagnetic field caused by EFT/B voltage and current to microprocessor protection device is simulated and countermeasures of electromagnetic shielding and space isolation are taken to cut off the coupling path. Simulation results show that, EFT/B coupled to microprocessor protection devices is effectively attenuated by electromagnetic isolation countermeasures.