纳秒级脉冲作用下ZnO压敏电阻级间能量配合关系的研究OA

Aiming at the problem of damage to power system caused by nanosecond strong electromagnetic pulse,based on the response characteristics of varistors and the principle of parallel operation of two-stage varistors,the response characteristics of varistors with different parameters under 20/500-550 ns waveform were analyzed by changing pulse injection voltage and combining with filter theory.The advanced design system(ADS)simulation software was used to design.The simulation results were as follows:The butterworth low-pass filter with loss less than 0.3 dB was inserted within the frequency of 50 Hz,and the filter was connected in series between two varistors with the same volt-ampere character-istics for pulse injection test.The experimental results show that with the increase of injection voltage,the peak overshoot voltage of the single chip varistor increases gradually,and the clamp voltage is basi-cally unchanged,which is positively correlated with the voltage.In parallel operation,the series filter can effectively limit the residual voltage level of the second stage varistor and reduce the residual current of the second stage.The residual voltage of the latter stage can be limited to less than 1.4 kV when the nine-order filter is connected between the varistor stages,which meets the electromagnetic pulse protec-tion requirements of the middle and low voltage power lines in relevant specifications.The research results have certain reference value for the protection of nanosecond strong electromagnetic pulse of varistors.