八侧差动保护原理研究  

Principle investigation of eight-side differential protection

作　　者：李晓华[1] 尹项根[1] 张哲[1] 陈德树[1] 

机构地区：[1]华中科技大学电力系,湖北武汉430074

出　　处：《电力自动化设备》2002年第5期1-3,共3页Electric Power Automation Equipment

摘　　要：针对葛洲坝大江电厂特殊的主接线方式———联合扩大单元接线 ,以其主变压器保护配置为例 ,提出一种适用大容量高压变压器保护双重化配置方案。采用 2种不同的差动保护原理及对应的制动方案 :二次谐波制动的常规相量差动和虚拟三次谐波制动的采样值差动。前者灵敏度高 ,但在变压器空合于故障时 ,动作速度不快 ;后者存在动作模糊区的问题 ,在变压器发生小匝数轻微短路时可能不能保护 ,而在合于故障时可以满足“速动”的要求。 2种不同的保护原理相互配合 ,可同时兼顾动作速度和灵敏度 2个方面 。According to the special main connection of Dajiang power plant of Gezhouba—united and expanded unit connection,and with the main transform protection as example;a double protection scheme for large capability HV transformer is brought forward.This scheme applies two different differential protection principles and their protective criteria:the common phasor differential protection restrained by second harmonic and the sampling differential protection restrained by virtual third harmonic.The former has high sensitivity,but low action speed when transformer closing to fault;the latter can meet the requirement of “accelerated trip”when transformer closing to fault,but has a vague zone and may function improperly for slight inter turn SC of transformer.The two protection principles cooperate with each other for both sensitivity and speed.It is a practicable double protection scheme.

关 键 词：八侧差动保护原理 励磁涌流 采样值差动 变压器 继电保护 电力系统 

分 类 号：TM772[电气工程—电力系统及自动化]