一种“小排油”方式更换换流变中性点套管的方法

Method of Replacing Transformer Neutral Point Bushing in Mode of "Partial Oil Discharge"

某±500kV换流站已投运近20年,其中性点套管由于制作工艺不良或受运行环境影响,先后发现4支中性点套管需要更换。以往进行的换流变中性点套管更换采用整体排油的方式,全流程工期约需15天,单只套管更换将降低直流能量可用率4.1%。本文中作者根据该换流变结构设计出可以满足部分排油进行中性点套管更换的装置及作业流程,并在该站备用换流变上成功实施,弥补了该站换流变中性点套管更换技术的短板,为类似问题提供了借鉴经验。

The ±500kV converter station has been in operation for nearly 20 years, and 4 neutral point bushingshave been found to need to be replaced due to poor manufacturing process or operating environment. In the past, the replacement of the commutator neutral point bushing adopted the method of integral oil discharge, and the whole process took about 15 days, and the replacement of a single bushing will reduce the DC energy availability rate by 4.1%. According to the commutation structure, a device and operation process are designed to meet the requirements of the neutral point bushing replacement of part of the oil discharge, and the standby converter of the station is successfully implemented, which makes up for the shortcomings of the commutation neutral point bushing replacement technology of the station and provides reference experience for similar problems.