新型大型发变组主保护方案的研究与试验——微机故障分量功率方向保护的应用

The Research and Test of A New Protection Scheme for Large Generator-Transformer Units The application of the digital direction relay based on fault-components

本文提出新型大型发变组主保护方案,其特点是基于故障分量原理,无需发电机中性点量,能够适应于各种绕组结构的发电机。文中围绕新方案的判据和算法,装置的硬软件构成进行讨论,并对动态模拟实验及其结果作了介绍。

A new micro-computer based protection scheme for large generator-transformer units against various asymmetrical short-circuit faults is presented in this paper.In this new scheme, three digital direction relays are suggested to replace trandifional generator and generator-transfotmer differential protections.The scheme features the phase comparison between the fault components of negative-sequence voltages and currents only detected at generator and transformer terminals, therefore it has a very high sensitivity and is suit for various neutral connections of generator stator windings, such as a huge hydro-generator with only one neutral other than three phase neturals withdrawn to the outside of the generator.This paper presents criteria and algorithms about the new scheme, discusses the hardware of the device and also introduces laboratry generator-transformer unit tests and some results.