宜宾换流站阀水冷系统应对交流电网扰动改进措施分析

Analysis on Improvement Measures for Valve Cooling System of Yibin Converter Station to Deal with Disturbance of AC Power Grid

摘要:

阀水冷系统是特高压直流输电系统的重要组成部分，当特高压直流系统两端的500kV交流电网突发扰动时，会导致阀水冷系统保护动作，造成负荷丢失。简述复龙、中州换流站阀水冷系统造成的事故，并对复龙、中州换流站事故原因进行简单分析。在此基础上分别对宜宾换流站的水冷系统在主循环泵启动方式、站用电备自投与主循环泵切换时间、主循环泵电源开关选型等方面作出了改进措施，有效增强了阀水冷流量保护抵抗交流电网扰动的能力，明显提高了宾金直流输电系统运行的可靠性。

关键词:特高压直流; 阀水冷系统; 交流电网突发扰动

Abstract:

The converter valve cooling system is an important part of ultra － high voltage direct current ( UHVDC) transmission system． When 500kV AC power grid at both ends of UHVDC system has disturbances，the protection of valve cooling system will act which makes load losing． The accidents of Fulong and Zhongzhou converter stations are introduced briefly，and the reasons of their valve cooling system problems are analyzed． Then the valve cooling system of YiBin converter station is improved on the way by modifying the start － up mode of main circulation pump，reducing the time of closing the spare power automatic switch and the spare circulation pump switch and changing the switch of main circulation pump power． Those measures effectively enhance the ability of valve water flow against the disturbances of AC power grid，which significantly improves the operation reliability of Bin － Jin DC transmission system．

Key words:特高压直流; 阀水冷系统; 交流电网突发扰动