变压器差动保护二次接线探析

Discussion on Secondary Wiring of Transformer Differential Protection

电力变压器绕组存在的Y接线和△接线方式使得变压器一、二次侧电流存在相位差,若电流互感器二次接线与变压器绕组接线方式不匹配就会导致差动保护回路中产生不平衡电流,容易造成变压器差动保护误动作,影响电力系统的安全运行。通过福清核电厂前区变电所变压器差动保护误动作案例,介绍变压器差动保护的工作原理,探讨电流互感器二次接线方式对变压器差动保护的影响,阐述电流互感器二次接线相位变换以补偿差动保护不平衡电流的方法。

Due to the Y wiring and△wiring of the power transformer winding,there is a phase difference between the primary and secondary side currents of the transformer.If the secondary wiring of current transformer does not match the.wiring mode of trans former winding,it will lead to unbalanced current in the differential protection circuit,which is easy to cause trans former differential protection malfunction and affect the safe operation of power system.Taking the fault op-eration of transformer differential protection in the former substation of Fuqing Nuclear Power Plant as an example,the working principle of transformer differential protection is introduced,the influence of the secondary wiring mode of current transformer on transformer differential protection is discussed,and the method of phase transformation of secondary wir-ing of current transformer to compensate for the unbalanced current of differential protection is explained.