小电流接地系统单相接地电流安全测量方法

小电流接地系统单相接地电流的大小对供、配电网运行的安全性和可靠性有很大影响。介绍了一种简单、易实施、测量精度高的小电流接地系统单相接地电流的测量方法。通过将任一相经电阻接地，测得经电阻接地的接地电流值、相电压值和零序电压值，便可以方便地计算出电网的单相接地电流值。用这种方法不仅可以方便地测出单相接地电流的大小，还可以区分出单相接地电流的有功分量和无功分量，其无功分量是容性的还是感性的。现场测量结果证实了该方法的有效性。

A NEW METHOD FOR MEASURING SINGLE-PHASE-TO-GROUND CURRENT IN SYSTEM WITH NEUTRAL EARTHED VIA PETERSON COIL

The magnitude of the single- phase- to- ground current in the power network with neutral earthed via Peterson coil has greatinfluence on the security and reliability of the distribution power system.However,there isn'ta satisfied m ethod for measuring it.This paper proposes a simple,convenient and relatively accurate method for measuring such a current,i.e.,to connect a resistance between the phase conductor and ground then measure the current flowing in this resistance,the phase voltage and the zero- sequence voltage.With these measured data,the single- phase- to- ground current wherever in the network can be calculated.This m ethod can not only m easure the magnitude of the single- phase- to- ground current,but also distinguish its active and reactive components and determine whether the reactive component is capacitive or inductive.Field measuring results verify the feasibility of this m ethod.