极端情况下电子式电流互感器防护措施

在遭受过电压、过电流等极端情况时,电子式互感器易受冲击而导致性能下降或损坏。以一种有源电子式电流互感器为例,介绍了其在极端情况下的各环节,如LPCT(低功率电流互感器)、Rogowski线圈、高压侧电源系统和高压侧信号处理电路等的防护问题,并给出了相应的措施及其设计依据。对防护措施引入的误差进行了分析,指出通过选择合适的标称电压,可以减弱防护器件性能对测量准确度的影响。型式试验结果表明,采用该措施的一种电子式电流互感器满足IEC 0.2级要求,验证了所提出措施的有效性。

Protection Methods for Electronic Current Transformer During Extreme Circumstance

The performance of electronic current transformer could been deteriorated,even destroyed during some extreme circumstance,for example,overvoltage or over current.This paper introduces the protective problems of several parts for ECT,LPCT(low power current transformer),Rogowski coil,power supply system and signal processing circuits in high-voltage side,the corresponding protective methods and design criterions have been proposed.Errors on LPCT induced by leakage current are analyzed.The analysis results show that errors induced by protection components could be ignored through selecting appropriate parameters.Type test results show the ECT based on the proposed methods meets IEC 0.2 class requirements,and the validity of the measures have been proved.