直流电缆雷电冲击电压安全裕度研究

Safety margin of DC cable under lightning impulse voltage

高压直流电缆是柔性直流输电技术的关键装备,直流电缆的绝缘厚度设计以雷电冲击电压安全裕度为重要依据。为了获得直流电缆的安全裕度,文中提出了直流电缆雷电冲击电压安全裕度试验方法,建立了相应的试验回路,对冲击电压波形参数进行了计算、仿真和验证,获得了波前时间为1~5μs、半峰值时间为40~60μs的冲击电压波形;提出了直流电缆雷电冲击电压安全裕度的分析方法,计算了电缆绝缘的电场分布。研究表明,文中所提方法可以获得直流电缆的雷电冲击电压安全裕度,为高压直流电缆绝缘厚度设计提供了依据。

HVDC cable is the key equipment of HVDC flexible transmission technology,and the insulation thickness design of HVDC cable is based on the safety margin of lightning impulse voltage.In order to obtain the safety margin,test method of safety margin under lightning impulse voltage is proposed in this paper,and impulse waveform is calculated,simulated and verified.Impulse voltage waveforms with wavefront time(1~5)μs and half peak time(40~60)μs is obtained.An analysis method of lightning impulse voltage safety margin of dc cable is presented,and the electric field distribution of cable insulation is calculated.The research shows that the safety margin of HVDC cable can be obtained by using the test method proposed in this paper,the research results provide a basis for the design of HVDC cable structure.