分裂导线表面电场对换流站操作过电压影响研究

Research on Influence of Surface Electric Field of Spliting Conductor on Operating Over-Voltage of Converter Station

直流导线表面电场影响换流站操作故障后的电压稳定性,威胁电网安全运行,研究导线表面场强与换流站操作过电压的关系意义重大。采用ANSYS Maxwell搭建特高压直流导线模型,模拟导线表面电场分布,分析分裂间距对表面场强的影响。基于PSCAD建立±800 kV换流站仿真模型,模拟3种典型换流站故障,研究不同分裂间距下表面场强对故障电压暂态特性的影响。结果表明,分裂间距为0.35~0.45 m时,导线表面场强小,导线间电磁感应弱,换流站故障后电压的可控性高,可有效降低系统过电压危害。研究结果可为实际工程建设中优化换流站直流输电线路的结构性能、提高输电电压稳定性提供参考。

The voltage stability of the converter station after operation failure is affected by the electric field on the surface of the DC conductor,and the safe operation of the power grid is threatened.It is of great significance to study the relationship between the conductor surface field strength and the operating over-voltage of the converter station.The UHVDC wire model is established in ANSYS Maxwell,the electric field distribution on the wire surface is simulated to analyze the influence of the split spacing on the surface field strength.The±800 kV converter station simulation model is established based on PSCAD,and three typical converter station faults are simulated to study the effect of surface field strength on the fault voltage transient characteristics under different splitting intervals.The results show that the split spacing is selected between 0.35~0.45 m.The surface field strength of the conductors is reduced.The electromagnetic induction between the conductors is weakened.The voltage controllability after the converter station failure is improved,and the system over-voltage hazards are effectively reduced.The research results can be used as a reference in optimizing the structural performance of the DC transmission line of the converter station and improving the stability of the transmission voltage in actual engineering construction.