ZnO压敏元件雷电流冲击试验残压波形分析

The Residual Voltage Waveform of ZnO Varistors Subject to a 8/20μs Surge Current Test

研究了ZnO压敏元件在8/20 ms雷电波冲击试验时的残压波形。实验观察到残压波波前尖峰来源于所采用的放电回路触发元件——铜球间隙;在RLC回路临界点附近,随着冲击电流峰值的增大,残压波波尾从非振荡衰减过渡到大幅度的过零振荡;残压波峰值超前于电流波峰值,说明ZnO压敏元件在冲击电流作用下呈现出电感性,且放电电流越大,呈现的电感性越大;元件厚度越大,呈现的电感性也越大。

Investigated was the residual voltage waveform of ZnO varistors subject to a 8/20 祍 surge current test. The observed frontal spikes of the residual voltage are caused by the ignition gap. Near the critical point of the RLC-circuit, the residual voltage waveform changes form non-oscillating attenuation mode to distinct across zero oscillating mode when the peak current increases. The residual voltage peak appears in advance of the surge current peak. This implies the ZnO varistor is of inductance. The inductance increases along with the increase of the peak current and the thickness of the varistors.