南方电网西电东送通道无功功率流动机理分析

Analysis on Reactive Power Fluxion Mechanism of the West to East Transmission System in China Southern Power Grid

南方电网西电东送通道上长期存在送端从受端吸收无功功率的现象,该现象即使在受端电压低于送端电压的情况也存在,对此传统的无功功率流动理论难以解释。对该现象的机理进行了深入分析,发现输电线路的电阻对于无功功率的流动具有一定的影响,电阻的存在使得两侧电压相当时受端系统注入线路的无功功率多于送端,且线路电阻越大、输送功率越多,送受两端注入线路无功功率的差值越大。因此,进行长距离输电线路无功平衡和无功配置分析时需要考虑线路电阻的作用,在受端可适当增加配置无功补偿装置。

A phenomena has been found for years in CSG that the active power sending side of the West to East transmission system absorbs reactive power from the receiving side, even when the voltage of the receiving side is lower than that of the sending side. This phenomena, however, is hard to explain with the traditional reactive power theory. This paper analyzes the mechanism of the phenom-ena, founding that the resistance of transmission lines has such an influence on the reactive power fluxion that the reactive power injec-ted into the transmission line from the receiving side is larger than that from the sending side, and the influence will increase with the resistance or the transmitted active power increasing. Therefore, the influence of the line resistance should be considered in reactive power balancing and allocating, and more reactive power devices should be allocated in the receiving side.