局放仪脉冲极性响应不对称误差测评方法研究

Researching the Method to Evaluate the Asymmetric Error of Pulsed Polarity Response for PD Instrument

脉冲极性响应不对称误差是表征局放仪性能的重要指标之一。为了更准确地测评局放仪,在根据脉冲电流法的局放仪原理和相关局放仪校准规范基础上,提出了在局放仪带宽内产生与局部放电频谱接近的电压脉冲信号,避开耦合装置直接注入局放仪的方法,并通过PRPD谱图分别统计正负脉冲极性响应的平均放电量,对局放仪的脉冲极性响应不对称误差进行测评。以PDCheck局放仪为例,详细介绍了测评的过程及结果分析。试验结果表明,PDCheck局放仪的脉冲极性响应不对称误差最大值为3.83%,小于标准中的±10%,满足局放仪校准规范,并验证了该方法的准确性和有效性。

The asymmetry error of pulse polarity response is one of the important indicators to characterize the PD instrument.In order to evaluate the PD instrument more accurately.Based on the PD instrument principle of the pulse current method and the calibration standard of the PD instrument system,a voltage pulse signal that is close to the partial discharge spectrum is proposed which occurs within the bandwidth of the PD amplifier,the method that inject the coupling device into the PD instrument directly is avoided,and the average discharge capacity of the positive and negative pulse polarity responses is calculated by the PRPD spectrum respectively,the asymmetry error of the pulse polarity response of the PD instrument is evaluated.Finally,taking the PDCheck PD meter as an example,the process of evaluation and the result analysis are introduced in detail.The experimental results show that the maximum error of the pulse polarity response of PDCheck PD instrument is 3.83%,less than 10% of the standard,which meets the requirements of PD calibration and verifies the accuracy and effectiveness of the proposed method.