±1000kV特高压直流输电系统设备电晕特性(英文)

Corona performance is an important factor should be taken into consideration in power transmission project designs.Power equipments operate in various environments which will affect their corona inception voltages and thus influence the operation safety of transmission systems.In this paper,corona characteristic tests of bus bars,shielding rings,simulated eight-bundled conductors,and insulators were carried out in areas with different altitudes up to 4 300 m.Simulation tests of environmental factors were carried out in a HVDC corona cage.Based on site tests,it is concluded that corona inception voltages of both bus bar and shielding ball increase with their height to the ground or their dimensions.The influences of water droplet,wind,icing and surface contamination on corona inception voltage were also obtained from the simulation tests.The corona inception voltage of mist is higher than that in saturated water droplets.Conductivity of precipitation has little impact on corona discharges.Corona inception voltage decrease with increasing wind speed.The influence on corona current of glaze is the biggest,and that of hard rime is more than that of soft rime.The impact of pollution material on corona discharge depends on the size of pollution particle.Test results obtained in this paper are solid reference for design of UHV DC transmission projects.