1000kV同塔双回特高压交流输电线路工频序参数测量计算

Measurement and Calculation of Power Frequency Sequence Parameters of 1000 kV UHVAC Double-circuit Transmission Lines on the Same Tower

为准确获得淮南—上海1 000 k V同塔双回交流输电线路的工频序参数,采用基于全球定位系统的异频双端同步测量方法测量试验中各相导线首、末端电压与电流;提出了将所测电压与电流代入长线方程来求解异频下的工频序参数的计算方法,并与单端测量所得结果进行比较。结果表明,采用所提出的双端测量计算法能够获得准确的工频序参数,与采用分布参数模型的单端测量计算结果相比,其差异百分比≤1.52%;而与采用常规集中参数算法的单端测量法相比相差较大,其中零序电阻差异百分比可达16.48%,这是因为单端测量法不适用于长距离线路的参数计算。将上述双端测量计算法用于测量特高压同塔双回交流输电线路淮芜Ⅰ线与Ⅱ线的工频序参数,获得了准确的结果,为继电保护及短路电流计算等提供了数据基础。

In order to obtain accurate power sequence parameters of the 1 000 kV AC double-circuit transmission lines on the same tower between Huainan and Shanghai in China, we applied a varying-frequency two-terminal synchronous method based on GPS to measure the voltages and currents at both ends of each phase conductor. We also proposed a calculation method that uses the measured voltages and currents in long line equations to obtain the power-frequency sequence parameters, and compared the calculation results with those obtained by the one-terminal measurement method. The results show that the proposed two-terminal measurement and calculation method is effective： compared with the one-terminal measurement method using distributed parameter models, the difference between results from the two methods is no more than 1.52%. However, the results from the proposed method are more different from those obtained by the one-terminal measurement method using lumped parameter model, with a difference up to 16.48%, mainly because the one-terminal measurement method is not fit for calculating the parameters of long transmission lines. Furthermore, we applied the proposed two-terminal measurement method to calculate the power-frequency sequence parameters of the 1 000 kV AC Huainan-WuhuⅠ and Ⅱ double-circuit transmission lines on the same tower and obtained accurate results, which provided data for the lines＇ relay protection and short-circuit calculation.