极端环境下816 kV高压直流隔离开关设备关键技术研究OA

816 kV DC disconnector is a critical component in±800 kV UHVDC converter stations,and its excellent insulation performance and reliable mechanical operation directly contribute to the safe operation of the system.Aim-ing at the extremely high altitude of 4 500 m and the extreme low temperature of-60℃,in this paper a systematic study on the wear resistance characteristics of the disconnector contacts and its insulation performance is carried out.By analyzing the influence of temperature on the wear amount of the silver coating layer and on the contact resistance,the evolution mechanism of contact resistance under low-temperature environments is revealed and,on this basis,the contact structure is optimized.The APDL command flow method is used for parametric modeling and electric field simulation of the disconnector.The influence of such key parameters as support height,grading ring dimensionsand distance across open contacts on electric field intensity is analyzed,and the optimal shielding structure suitable for 4 500 maltitude conditions is determined.Based on these findings,a prototype of the 816 kV DC disconnector is de-veloped and subjected to insulation tests at 4 500 m altitude conditions.The results demonstrate that the developed product meets the engineering application requirements for high-altitude regions and exhibits excellent insulation performance and operational reliability.The research result can provide a theoretical basis and data support for the design of HVDC disconnector in extreme environments.