发电机组误上电事故的继电保护动作分析

发电机组误上电事故常常被人忽视,大容量机组误上电事故的危害则超出想象。针对近期国内一次发电机组误上电事故,较为详细地分析了事故中涉及到的发电机误上电保护、程序跳逆功率保护、失磁保护、定子绕组过负荷保护和转子过电压保护的动作情况。根据发变电组保护的整定和动作情况,找出此次误上电事故中主设备没有得到有效保护的根本原因。最后建议:300 MW及以上的发电机组都应装设专门的误上电保护装置,同时,机组并网前,应对转子过电压保护系统做全面的检查。

Analysis of reaction of relays to inadvertent energization of a generator set

The inadvertent energization of generator sets is often neglected.However,the harm of mis-energization of large-capacitygenerators is beyond imagination.Aiming at a recent mis-energization accident of a generator set in China,a thorough analysis is madeof the relevant protection of generator mis-energization,reverse power,losing excitation,overload of stator winding and overvoltage ofrotor.Based on the setting and operation of the relays,the essential causation of the main apparatus protection failure in the accident isfound.At last,it is suggested that generator sets of 300 MW and above should be equipped with special protection against mis-energization;meanwhile,the overvoltage protection system for rotors be thoroughly inspected before the grid connected operation ofunits.