接地极线路架设方式对单极接地故障下过电压沿线分布的影响

The Influence of the Grounding Electrode Line Erection Mode on Overvoltage Distribution Along Single Pole Grounding Fault

接地极线路的安全稳定运行对整个特高压直流输电系统的可靠性有重要影响。对于通道紧张的输电走廊,接地极线路可与直流输电线路同塔架设。针对不同的直流接地极线路架设方式,研究了接地极线路在单极接地故障下内部过电压的沿线分布规律。结果表明:1)对于单独架设的接地极线路,其内部过电压的幅值从换流站中性母线到接地极址呈近似线性减少的趋势;2)对于与直流输电线路同塔架设的接地极线路,其内部过电压的沿线幅值分布为非线性,同塔架设段内的过电压可能高于换流站出口处。在进行接地极线路绝缘配合设计时,应考虑接地极线路的架设方式。

Safe and stable operation of grounding electrode line is important to the reliability of the UHVDC transmission system. For transmission corridors with tense channels,grounding pole lines can be erected on the same tower as HVDC transmission lines. Aiming at different erection modes of DC grounding electrode line,the distribution of internal overvoltage along single pole grounding fault is studied. Results show that: 1) for the individual grounding electrode line,the amplitude of internal overvoltage decreases approximately linearly from the neutral bus to the grounding electrode;2) for the grounding pole line erected on the same tower as the HVDC transmission line,the amplitude distribution of internal overvoltage along the line is non-linear,and the overvoltage in the same tower section may be higher than that on the neutral bus. When designing insulation coordination of earth electrode line,the erection mode of grounding pole line should be considered.