特高压电容式电压互感器误差在线同级比对技术研究

Research on on-line peer comparison of UHV capacitor voltage transformer error

作为特高压计能装置的重要组成部分,电容式电压互感器(Capacitor Voltage Transformer,CVT)需要定期进行误差校验,以判断其是否符合准确度等级要求。当前CVT误差校验存在着几个问题急需解决:(1)高抗出线侧CVT交接试验无法在全电压下进行;(2)停电校验困难;(3)校验结果偏离CVT在线状态下的实际值。为此迫切需要开展在线同级比对研究。在此背景下,以特高压CVT的误差特性为研究对象,进行了在线误差校验研究装置和试验方法研究,并将研制的在线校验系统,用于特高压浙福工程中的特高压电容式电压互感器的误差现场试验,获得了CVT在运行过程中的误差特性数据,验证了该方法可以实现对CVT的在线同级比对。

As an important part of the UHV energy metering device, Capacitor Voltage Transformer（CVT） needs periodic error checking to determine whether it meets the accuracy level requirement. At present, there are several problems needed to be solved in CVT error checking：（1） It can not carry out the full voltage acceptance test on the CVT beside the high resistance;（2） Off-line calibration is hard to implement;（3） The verification result deviates from the actual value of CVT online state, so it is urgent to carry out on-line peer comparison research. Under this background, this paper takes the error characteristics of UHV CVT as the research object and studies the research device and test method of on-line error checking.The developed online checking system is used in error field test of UHV capacitor voltage transformer of Zhejiang-Fuzhou UHV project and the on-line error characteristics data during CVT operation is obtained, verifying that using the method can achieve CVT on-line peer comparison.