基于数字恢复的脉冲电阻分压器实验研究

Research on Resistor Divider of Fast Pulse Voltage Based on Digital Reconstruction

变电站中雷击、开关操作以及故障引起的强电磁脉冲对保护控制电缆和弱电设备产生很大的干扰,为了研究干扰机理,基于快速傅里叶变换方法研究了高频脉冲电压电阻分压器。通过实验分析了普通碳膜电阻阻抗的频率特性,从频率特性可见模型很复杂;测量了51kΩ和51Ω电阻分压器的原边和副边时域脉冲电压;应用快速傅里叶变换分析了分压器频率特性,提出应用数字恢复方法恢复分压器原边侧电压。讨论了影响电阻分压器信号数字恢复的因素。实验表明应用本文方法对提高电阻分压器的上限频率很有效。

The electromagnetic pulse generated by lightning strikes, switching operations and power faults in substa- tions interferes the protection, control cable and secondary equipment. In order to research the interference mechanism, on the basis of FFT transformation the frequency characteristic of a resistor divider was researched. The impedance frequency characteristic of a resistor was measured, and the frequency characteristic was determined. The time domain impulse voltages of a divider composed by 51 kΩ and 51Ω were measured. The frequency characteristic of a divider was calculated using FFT. According to the different waveforms and different acquisition times, using frequency characteristics of divider and measured voltage, the primary side voltages of the divider in time domain were reconstructed. The factors affecting the reconstructed effect were discussed. The experimental results and theoretical analysis show that this signal reconstruction method is valid.