换流变压器分接开关控制及典型故障分析

Control Principle and Typical Fault Analysis on Load Tap Changer of Converter Transformer

换流变压器分接开关可以维持阀侧直流电压恒定,补偿电压波动,实现直流输电系统降压运行,在直流输电系统中至关重要。分接开关的档位调节是否正确,直接关系电网的安全稳定运行。介绍±800 kV沂南换流站分接开关控制原理,针对网侧采用分层接入技术的分接开关控制原理进行重点分析。结合分接开关调试期间典型故障,对故障类型及处理过程进行分析,为今后分接开关的故障处理提供参考。

The on-load tap-changer is crucial in high voltage direct current transmission system for maintaining the constant DC voltage of valve side,compensating the voltage fluctuation and realizing the step-down operation.Accuracy of gear adjustment is directly related to the safe and stable operation of the power grid.The control principle of on-load tap-changer in ±800 kV Yinan converter station is introduced in this paper.The control principle of on-load tap-changer which uses multiinfeed technology is analyzed emphatically.According to the typical fault analysis,the fault type and treating during commissioning process are introduced,which provide references for the fault treatment of tap changer in HVDC projects in the future.