高压电流互感器容性泄漏误差原理及测试方法研究

Research on Principle and Test Method of Capacitive Leakage Error of High VoltageCurrent Transformer

高电压电流互感器在额定电压下的容性泄漏电流对互感器的误差有一定的影响。为了准确地测量容性泄漏误差,通过理论推导得到容性泄漏电流产生的机理和其对电流互感器误差影响的模型,提出了一种改进的可以测量微安级泄漏电流幅值和相位的方法,即参考锁相法,分析了施加电压电流测量法和参考锁相法的优缺点,并采用所提方法完成了一台高压标准电流互感器容性泄漏误差测试。通过试验与施加电压电流测量法在各工况下进行比较,验证了理论和测试方法的一致性,但对高准确度等级的高压电流互感器,参考锁相法更实用,研究对高压电流互感器的设计及检测人员有一定的借鉴作用。

The capacitive leakage current of high voltage current transformer at rated voltage has some effect on the error of the instrument transformer.For measuring the capacitive leakage error accurately,the mechanism of capacitive leakage current generation and the model of its influence on the error of the current transformer are obtained by theoretical derivation.A kind of improved method which can measureμA class leakage current amplitude and phase,also known as reference phase lock method,is proposed.The pros and cons of applying voltage and current method and the reference phase lock method are analyzed.The capacitive leakage error test of a set of high voltage current transformer is measured by the proposed method.The agreement between the theory and the test method is verified by way of testing and comparison of applying voltage and current methods at various conditions.The reference lock phase method is more practical for high voltage current transformer with higher accuracy class.The study has some reference to both design and testing engineers of high voltage current transformer.