During the impulse voltage comparison test, it is important to keep the waveforms smooth for obtaining consistent experiment results, especially for the front time parameter. However, steps or oscillations are often found on the front of the waveforms. The authors propose a theory that these oscillations can be caused by the resistors in the damped capacitive voltage divider, which often serves as the load capacitor in the impulse voltage generation circuit. The theoretical analysis, numerical simulation, and experimental results are performed, and a good agreement has been found in support of the proposed theory. Furthermore, the waveform parameters measured by two resistive reference standard systems were found to be influenced by the shape of the waveform and the oscillation on the front. It is recommended to avoid using a damped capacitive divider as the load capacitor but use an impulse capacitor with low equivalent series resistance instead. This would help to eliminate this common cause of oscillation on the front of the lightning impulse voltage waveform. Waveform uniformity and uncertainty of the result could then be improved during the comparison of reference measuring systems.

中文翻译：

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负载电容引起的雷电冲击电压波形前端谐振

在脉冲电压对比测试过程中，保持波形平滑很重要，以获得一致的实验结果，尤其是前沿时间参数。然而，阶跃或振荡经常出现在波形的前面。作者提出了一种理论，即这些振荡可能是由阻尼电容分压器中的电阻引起的，该分压器通常用作脉冲电压生成电路中的负载电容器。进行了理论分析、数值模拟和实验结果，并且发现了支持所提出理论的良好一致性。此外，发现由两个电阻参考标准系统测量的波形参数受波形形状和前端振荡的影响。建议避免使用阻尼电容分压器作为负载电容，而使用等效串联电阻低的脉冲电容代替。这将有助于消除闪电脉冲电压波形前端振荡的常见原因。然后可以在比较参考测量系统期间改进结果的波形均匀性和不确定性。