350MW发电机组高压转机低压减载保护方式的设计优化

350 MW发电机机组低压减载功能使用6 kV高压转机综合保护装置的附带功能,未使用6 kV母线电压互感器屏专用综合保护装置低压减载功能,两种方式都能满足低压减载功能,但使用前者在处理电压互感器断线事件时存在一定风险,处理不当有引发低电压减载动作的可能,使高压转机跳闸,进而引发机组跳闸事故。功能优化后的低电压减载功能系统简单集中,处理电压互感器断线缺陷简单、省时,有效避免低电压减载保护误动,引发机组跳闸非计划停机。

Design Optimization of Low-Voltage Deloading Protection Mode for High Pressure Transfer of 350 MW Generator

The low voltage deloading function of 350 MW generator unit adopted the supplementary function in the integrated protection device of6 kv high -voltage transfer , instead of low voltage deloading function of special comprehensive protection device in the 6 kv bus voltage transformer screen .Both implementations can satisfy the function of low voltage deloading , but they are used in the treatment of the voltage transformer disconnection events when there is a certain risk , improper han-dling with low electricity may reduce load action , make high pressure transit trip , causing the unit trip accident .Low elec-tricity reduce load function after function optimization system is simple , and save time , voltage transformer disconnection defect effectively avoid low electricity reduce load protection misoperation ,trigger unit trip planned downtime .