六脉冲下金属氧化物压敏电阻单片与双片并联的性能分析

Performance analysis of parallel connection of single MOV and two parallel MOVs under multiple strokes

为了研究在多脉冲下,雷电保护器中金属氧化物压敏电阻(MOV)单片与双片并联的性能,利用多脉冲发生设备,设置波形8/20μs,电流幅值20kA,脉冲间隔50ms的6个模拟的高压雷电脉冲,对单片与双片并联的MOV进行高压冲击试验,每次冲击间隔至样品恢复室温,对比测试单片20kA与双片10kA并联的伏安特性,分别分析它们的各自耐高压的性能。研究发现,多脉冲下双片并联的耐冲击性能明显优于单片;多脉冲下MOV的散热能力对耐受性能起重要作用,而双片并联的散热能力较单片更好。因此多脉冲下双片10kA并联比单片20kA更具可靠性和经济性。

This paper studies the performance of the single metal oxide varistor (MOV) and two parallel MOVs in surge protection device (SPD) under multi-pulse strokes. Using the multi-pulses generation equipment,8/20 μs high voltage lightning pulse are applied to MOV with 20kA amplitude and 50 ms time interval. After each stroke,the temperatures of tested MOVs are decreased to room temperature. The voltage-current characteristics are then compared between single MOV (20kA) and two parallel MOVs (10kA).Results show that the impact resistance of two parallel MOVs is better than that of the single MOV. The heat dissipation of MOV under multiple pluses plays an important role in the impact resistance,while capacity of heat dissipation for the two parallel MOVs is much better than single MOV. Therefore,the two parallel MOVs (10kA) is much reliable and cost-effective than the single MOV (20kA).