测量经消弧线圈接地电网中脱谐度的新方法

A New Measurement Method of Off Tuning Degree in the Distribution Network of Neutral Resonant Grounding

提出基于外加变频信号法测量配电网脱谐度的新方法．本方法采用带ＰＴ的消弧线圈，从 ＰＴ低压侧注入零序恒流信号，通过频率扫描确定系统的谐振频率，再由公式计算出脱谐度．外加信号法测量脱谐度不影响系统正常运行，且不受系统运行的影响．使用本方法可将脱谐度的测量从高压倒移至低压倒，测量安全快速、操作简单且准确度高．用本文提出的测量原理设计了一套测量装置，并通过了现场测试．

This paper presents a new method of Off Tuning Degree's measurement based on injecting current in distribution network. Various frequency constant current is injected to second side of PT (potential transformer) which the petersen coil is the first side. This principle is not affected by system operation. It has high precision and high reliability. A device for measuring off tuning degree based on the principle above- mentioned is developed, which have passed the practical test through measurement in Fuyang power station in Hebei province. Operational experience shows that this method is effective.