±1000kV/±1100kV特高压直流输电系统换流站的绝缘配合(英文)

The study result on insulation coordination of ±1 000 kV and higher voltage grade ultra-high voltage(UHV) DC converter stations is presented.Aiming at the ±1 000 kV UHVDC system,influences on arrester configuration and converter transformers insulation levels of converters' connections are discussed based on three schemes of serial converters structure: 500 kV+500 kV scheme,667 kV+333 kV scheme and 400 kV+400 kV+200 kV scheme.Comparing with the 500 kV+500 kV scheme,the 667 kV+333 kV scheme cannot reduce the maximum insulation level significantly and would bring problems to valve hall layout and operation controlling.The 400 kV+400 kV+200 kV scheme has no economic advantage as it increases land occupation and amount of equipments.According to comprehensive comparison,the 500 kV +500 kV scheme is recommended for ±1 000 kV UHVDC projects,and it is also suitable for higher voltage grade DC systems.According to system conditions of 1 100 kV,the switching impulse withstanding level(SIWL) of 2 100 kV and the lightning impulse withstanding level(LIWL) of 2 350 kV are feasible for ±1 100 kV UHVDC project,judging from the insulation levels.Meanwhile,arresters with higher performance are needed.