江西220kV同塔双回不换位线路不平衡度研究

针对江西省浔湖Ⅰ-Ⅱ双回线路存在严重的三相电流不平衡问题,提出采用电容器补偿措施减小三相电流不平衡度。由于对称分量法对不换位的输电线路误差较大,利用模分量法推导出三相不平衡度表达式;并根据GB/T 15543—2008《电能质量三相电压不平衡》中电网正常运行时负序不平衡度不超过2%的要求,理论计算补偿电容的大小。以江西220 k V浔湖双回线路为例,利用电磁暂态程序ATP/EMTP建立电容器补偿的同塔双回输电线路模型。理论与仿真结果表明:采取合理配置补偿电容可以减小线路三相不平衡度。

Research for Un-transposed 220kV Double-circuit Lines on the Same Tower in Jiangxi

To minimize the unbalance degree of three-phase current which exists in Xun Lake I-II double-circuit transmission lines in JiangXi, capacitor compensation should be adopted. Due to the large error of symmetry component method, the expression of unbalance degree of three-phase current should be induced by modal analysis. And calculate the value of the compensation capacitor according to the Power quality Three-phase voltage unbalance which requires that when the network operates normally, the unbalanced degree of current should under 2%. Take the 220kV double-circuit transmission lines in JiangXi Xun Lake I single-circuit line for example, the double-circuit transmission lines on the same tower model of the capacitor compensation was established on electro-magnetic transients program ATP/EMTP. The theoretical and simulation result shows that the method of allocating compensation capacitors reasonably can reduce the unbalance degree.