山西晋中500kV变电站3号主变压器扩建问题研究

Study on Expansion of No.3 Main Transformer of a 500kV Substation in Jinzhong,Shanxi

由于山西晋中电网与太原南部电网负荷增长迅速,急需扩建晋中500 kV变电站3号主变压器。为降低晋中220 kV母线侧短路电流,3号主变压器扩建后需采取220 kV母线分母措施,过渡期内3号主变压器与2号主变压器并列运行。在2台主变压器容量与阻抗电压参数均不相同的情况下,针对其并列运行期间可能产生的负荷分配不均匀以及循环电流问题进行分析,给出了详细的结论和建议。

Because of the rapid increase of power load in both Jinzhong and southern part of Taiyuan power grid,it has been an urgent need to expand the No.3 main transformer of a 500 kV substation in Jinzhong.The generator denominator measure should be taken in the No.3 main transformer after the expansion in order to reduce the short-circuit current at bus side of 220 kV in Jinzhong,so the No.3 and the No.2 main transformer will be in parallel operation during the transition period.On the condition that the capacity and impedance voltage parameters of the two main transformers are different,the unbalanced load distribution and circulating power problems that may occur in the parallel operation are analyzed,and corresponding conclusion and suggestions have been proposed in detail.