冲击电流作用下二次系统骚扰电压统计特性及与抗扰度试验符合性研究

Disturbance Voltage Statistical Characteristics of Secondary System Under Impulse Current and Its Consistency With Immunity Test

换流站二次设备容易受到雷击、故障及开关操作产生的瞬态电磁骚扰的影响。为适应电力系统的发展,提高二次系统可靠性,建立符合工程实际的电磁兼容考核标准,在某特高压换流站开展了冲击电流入地试验,实测得到二次设备端口的骚扰电压,并采用随机加权法及自助置信区间的统计方法获得骚扰电压的特征参数,并与GB/T 17626.5《电磁兼容试验和测量技术浪涌(冲击)抗扰度试验》和GB/T17626.12《电磁兼容试验和测量技术振铃波抗扰度试验》进行了对比分析。结果表明,标准浪涌波在持续时间及下冲方面与实测波形符合性较差;100k Hz的标准振铃波与此次测量的骚扰波形相关性较差,降低频率至20k Hz波形相关系数可达到0.89;综合考虑骚扰电压的外推结果与实际故障发生时的冲击电流,建议将浪涌和振铃波抗扰度最高等级试验电压提高至6k V。

The secondary equipment of the converter station is susceptible to transient electromagnetic disturbances caused by lightning strikes, faults and switching operations. In order to adapt to the development of the power system, improve the reliability of the secondary system, and establish an electromagnetic compatibility assessment standard that meets the actual engineering requirements, an inrush current ground test is carried out at a UHV converter station. First, the disturbance voltage is measured at the secondary equipment port. Then the characteristic parameters of disturbance voltage is obtained through the random weighting method and the method of bootstrap confidence interval. Finally, these parameters are compared with the GB/T 17626.5 surge immunity test standard and the GB/T 17626.12 ring wave immunity test standard. The results show that the standard surge wave has poor consistency with the measured waveform in terms of duration and undershoot. The standard ring wave of 100 k Hz has a poor correlation with the disturbance waveform measured this time. Reducing the frequency to 20 k Hz may achieve a correlation coefficient of 0.89. Considering the extrapolation results of the disturbance voltage and the inrush current when the actual fault occurs, it is recommended that the test voltage of the highest level of surge and ring wave immunity increase to 6 kV.