220kV组合电子式互感器原理结构及挂网试验

Construction Principle and Application Test of 220 kV Combined Electronic Transformer

笔者介绍一种电流—电压组合型电子式互感器(ECVT)。该互感器含有两项核心技术,即自励源技术和等势腔技术,着重讨论了等势腔分压器的原理,如何以场—路平衡的方法达到屏蔽外电场干扰,实现电磁静默环境下的精密分压。还介绍了如何将自励源光隔离电流互感器和等势腔电压互感器2种技术有机地结合,形成一种电子式组合互感器,介绍这种产品在现场应用上的技术优势,并附有典型220 kV电站运行的试验记录。电站运行试验表明,组合式ECVT工作稳定,2个测量系统功能兼容,测量示值正确,是一种值得推广的结构方案。

This paper introduces a combined electronic current and voltage transformer （ECVT）. This transformer includes two core technologies, namely the self-excitation power supply technology and the equal potential cavum technology. The principle of voltage divider which based equal potential cavum structure and how to shield disturbance from outside electric field with balance of field and road so as to achieve precise voltage division in the electromagnetism silent environment are discussed emphasizely. It describes also how to combine two technologies and forming a new type of electronic combined transformers. The advantages of this transformer in applications and some testing records in a typical 220 kV substation are introduced as well. The practical operation conclusion indicates the combined ECVT works stably, two measurement systems are compatible, value of testing is correct, and this configuration is good for extend in applications.