在对交流输电线路实际运行特性进行分析的基础上,提出均匀补偿线路的基本思想来对输电线路进行建模。以500kV无损输电线路并联补偿和串联补偿为研究对象,分析集中补偿与均匀补偿的一致性,计算考虑无功补偿后输电线路的等值波阻抗和相移系数,据此对使用无功补偿提高线路输送能力的实施方法和效果进行分析。结果表明:线路无功补偿的效果是改变线路阻抗和相移系数,因此补偿度可理解为波阻抗的补偿;在补偿到线路等效特性阻抗的情况下,串联补偿提高了线路端口电压,并联补偿增加了线路端口电流,因而串联补偿时线路损耗较小;对于短距离输电线路,并联补偿和串联补偿方法都是可行的;对长线路来说,应考虑混合补偿的实施方案。
Based on the analysis of operation performance of AC transmission line, the thought of uniform compensation line is presented to model the transmission line. The agreements of the uniform compensation and the centralized compensation are analyzed for the 500 kV transmission line with parallel compensation and series compensation. The equivalent wave impedance and phase-shift coefficient are calculated when attributing the compensated reactive power to the transmission line. Calculated results show that the result of the uniform compensation line is to change the line impedance and the phase-shift coefficient and consequently the compensation degree can be thought as the compensation of wave impedance. The port voltage of transmission line is improved by the parallel compensation. The method of parallel compensation and series compensation are all feasible for the short distance transmission line. The implementation of hybrid compensation should be considered for the long distance transmission line.