7th International Conference on Electric Power Equipment– Switching Technology (ICEPE 2024)

82 / 2024-04-11 11:31:44

Research on surge arrester configuration and overvoltage stress of ±550kV DC GIS in offshore wind power system

offshore wind power, flexible DC system, ±550kV DC GIS, overvoltage protection, surge arrester configuration

DC gas-insulated switchgear (DC GIS) in offshore wind power system significantly reduces the occupy space compared to air-insulated switchgear, which reducing the cost of offshore platforms. In offshore HVDC systems, the DC GIS withstand considerable overvoltage during faults. Research of overvoltage stress in DC GIS is vital to the system. The study addresses the critical aspect of arrester configuration scheme and overvoltage stress of ±550kV DC GIS. Offshore wind power flexible DC grid connection with ±550kV symmetric unipolar system topology is stablished in PSCAD/EMTDC platform. Then, the paper investigates the overvoltage withstood by DC GIS surge arrester under different fault conditions and fault location. The study organizes and defines stress calculation criteria for GIS. Finally, the voltage stress level of ±550kV DC GIS are calculated and analyzed. The results show that ±550kV DC GIS switching impulse withstand voltage is over 1024 kV and lightning impulse withstand voltage is over 1090 kV in offshore wind power system.