厂用电切换引起厂变过流保护误动作的分析

Analysis on switching over station power which cause station transformer overcurrent protection maloperation

电厂厂用电切换过程中 ,常因合闸冲击电流过大而引起高备变过流保护动作造成的厂用电切换失败。此文就失败原因进行了详细的分析 ,指出失败的主要原因是合闸开关的合闸速度不够快及合闸相位不当造成冲击电流过大造成了高备变过流保护动作。由于快速合闸可以减小后续电流 ,这样不会对电气设备造成危害。因此建议采用快速开关以减小后续电流和过流保护加小延时的策略以保证切换成功。通过现场多次试验 。

Switching over station power often cause station transformer overcurrent protection maloperation.This paper makes a detail analysis for it and propose that the dominate reason is switching over slowly and rush current over setting point which cause station transformer overcurrent protection maloperation.For these reasons,quick break switch and timing relay are suggested to adopt in this paper.These two means get the desiring result which is supported by experiment on spot.