摘要
Abstract
Converter valve is the core part of the HVDC systems,and the thyristor,the core components of the converter valve,is the key to achieve rectifier and inverter.The light-triggered thyristor(LTT)of T2563 N80T-S34 is used in converter valve at ±800 kV Chuxiong Converter Station.LTT has integrated overvoltage protection function with low failure rate However,from the 22nd April,that the stage Ⅳ of the island commissioning for Yunguang DC system ended,to the 10th May in 2012,a total of 8 converter valve thyristor had failed.Taking into account that more than one thyristor failed in a short period of time,in this paper,the author describes the basic structure and the compo-nents of the converter valves for ±800 kV Chuxiong converter station;clarifies the conduction principle and failure mechanism of the LTT;combining with the thyristor failure situation,the system transient work condition analysis,parameters comparative analysis of the converter valve and the action analysis of the arrester,when the thyristor be-come failure,sums up the reason for the failure of LTT,and proposes solutions and preventive measures.关键词
换流阀/光触发晶闸管(light-triggered thyristor,LTT)/失效/过电压/措施Key words
converter valve/light-triggered thyristor(LTT)/failure/overvoltage/analysis
