特高压双回线路耦合效应的计算与分析

Calculation and Analysis of the Coupling Effects of the UHV Double-circuit Transmission Lines

同塔双回的特高压输电线路存在较为严重的耦合效应,为研究其产生机理及其影响因素,详细阐述了双回之间静电感应和电磁感应的产生机理与计算方法,通过建立等效电路模型,分析了换位方式对检修线路静电感应与电磁感应分量的具体影响,指出运行线路对检修线路的电容耦合参数和互感参数的不对称,是检修线路静电感应分量和电磁感应分量产生的主要原因。针对我国拟建的特高压同塔双回线路,基于ATP-EMTP仿真,计算了双回线路在不同工况和运行状态下的感应电压与电流。特别地,针对带并联电抗器的特高压同塔双回输电线路,研究了高抗补偿度和中性点小电抗取值对检修线路感应电压的影响,指出检修线路可能出现较大的感应谐振过电压。研究结果为特高压同塔双回输电线路的建设提供了有价值的参考依据。

There exist serious coupling effects between the ultra high voltage（UHV） double-circuit transmission lines, In spite of elucidating detailedly both the static and the electromagnetic coupling mechanisms, the impacts of the line transposition mode on the induced voltages and currents are analysed via established equivalent circuit model. It is concluded that the asymmetry of the coupling capacitance and inductance parameters is the principal cause to generate the static and electromagnetic coupling components. As a case study which incorporates UHV double-circuit lines to he built in east China, the induced voltage and current along the maintenance line under different eondi tions have been calculated through ATP-EMTP. Specifically, the influence of both the compensation factor and the neutral reactor value on the induced voltages along the maintenance line is investigated while shunt reactors are installed, which indicates that extremely high induced resonant overvolages may potentially happen in some critical cases. The research results present uesful reference for future construction of the UHV double-circuit transmission lines.