孙改改

摘 要：大型机组发电机电气量保护都按照双重化配置原则，由于发电机机端只有一组匝间专用PT，两套保护均取自匝间专用PT的开口三角，一旦该PT出现异常，两套定子匝间保护均会受到影响。目前，国内已多次发生定子匝间故障，并且某些机组由于未配置定子匝间保护，无法快速切除匝间故障，最终转化成相间短路故障，造成了巨大的经济损失。本文研究了一种既不依赖于匝间专用PT，同时又能达到纵向零序电压匝间保护性能的新原理。双套配置的定子匝间保护方案为：一套纵向零序电压匝间保护原理，另一套采用不依赖于专用PT的匝间保护新原理，实现两套保护输入通道的完全独立，提高发电机的安全性及可靠性。

关键词：发电机;纵向零序电压;匝间保护

中图分类号：TM31文献标识码：A文章编号：1003-5168（2020）16-0115-03

Abstract： The electric quantity protection of large-scale generator is based on the principle of double configuration. As there is only one group of PT dedicated to turn-to-turn， both sets of protection are taken from the open triangle of PT dedicated to turn-to-turn， two sets of stator turn-to-turn protection are affected. At present， there have been many stator turn-to-turn faults in our country， and some units can not cut off the turn-to-turn faults quickly because they are not equipped with stator turn-to-turn protection， which finally turns into inter-phase short circuit fault. In this paper， a new principle was studied， which not only does not depend on the inter turn special Pt， but also can achieve the performance of longitudinal zero sequence voltage inter turn protection. The two sets of stator turn to turn protection scheme are as follows： one set of longitudinal zero sequence voltage turn to turn protection principle， the other set adopts the new turn to turn protection principle which does not depend on the special PT to realize the complete independence of the two sets of protection input channels and improve the safety and reliability of the generator.

Keywords： generator;longitudinal zero sequence voltage; turn-to-turn protection

大型機组发电机电气量保护都按照双重化配置原则，由于发电机机端只有一组匝间专用PT，2套保护均取自匝间专用PT的开口三角，一旦该PT出现异常，2套定子匝间保护均会受到影响，因此，不符合双重化保护输入通道相互独立的要求。为了解决现有发电机定子匝间保护方案存在的上述问题，本文研究了一种既不依赖于匝间专用PT，同时又能达到纵向零序电压匝间保护性能的新原理。

1 国内发电机匝间保护现状

现代大型发电机的定子绕组，由于在定子同一槽的上、下层线棒会出现同相不同匝数的定子线棒，因而会发生发电机定子绕组的匝间短路故障，为此大型发电机要安装匝间保护。……