±800 kV云广直流输电系统串联双阀组换流变分接开关125℃闭锁调整分析及处理

Analysis and Dispose of Converter Transformer OLTC 125°C Blocking in Series Dual Groups of Yunnan-Guangdong ±800 kV DC Transmission Project

摘要: 南方电网所有直流输电系统中，±800 kV云广特高压直流首次使用了真空有载分接开关，本文首先介绍真空有载分接开关的工作过程，然后总结分析了云广±800 kV直流输电工程中换流变分接开关125℃闭锁调整的原因，对其存在的风险进行深入剖析，最后提出有效的处理措施，降低云广特高压直流输电系统闭锁的风险。

Abstract: Yunnan-Guangdong ±800 kV DC transmission project is the first project which uses vacuum on-load tap- changer in all DC transmission projects of CSG. The paper introduces the operation of vacuum on-load tap-changer firstly, then summarizes and analyzes the cause of converter transformer OLTC 125°C blocking in Yunnan-Guangdong ±800 kV DC transmission project, and analyzes its risk thoroughly, at last, some effective measures which can depress the risk of blocking both pole in Yunnan-Guangdong ±800 kV DC transmission project are given.