江西220 kV 同塔双回不换位线路不平衡度研究

摘要

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 compo-nent method, the expression of unbalance degree of three -phase current should be induced by modal analysis .And the value of the compensation capacitor was calculated according to the Power quality Three -phase voltage unbal-ance which requires that when the network operates normally , the unbalanced degree of current should under 2%.Take the 220 kV 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 compensa -tion capacitors reasonably can reduce the unbalance degree .%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 kV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。