三相V/V不等容牵引变压器差动保护方法及应用

Method and Application of Three-phase Differential Protection in Unequal Capacity V/V Connected Traction Transformer

针对三相V/V不等容牵引变压器提出了三相差动保护方案。中间相可任意选择A,B,C相,并根据两边相电流相差600+的特点来计算中间相电流幅值和相角。分析了牵引变电所和三相V/V接牵引变压器的接线方式,在此基础上给出了三相差动保护的接线方式、各相额定电流计算公式、校正公式和整定计算原则;详细介绍了整定计算实例和现场试验方案,对工程人员有一定指导意义。

Proposed a three-phase differential protection programfor the three-phase V/V connected traction transformer with unequal capacity. Intermediate phase can be optionally selected from A, B,C. And the amplitude and phase angle of the intermediate phase is calculated according to the other two phases which phase angle is difference form 600. Based on the analysis of the type of connection of traction substation and three-phase V/V traction transformer, the type of connection of the three-phasedifferential protection, each phase rated current formula, the correction formula and setting calculation principle are given. Details the seting calculation instance and field test programs, enginers significance.