35 kV变压器微机差动保护误动现象分析

Analysis of Misoperation of Microcomputer Differential Protection for 35 kV Transformer

微机保护较抽象,尤其对于Y,D接线方式的变压器,其高低压侧电流存在相位差,而差动保护为分相差动,所以需要对高低压侧电流相位进行角度误差补偿校正。对Yd-11联接组别变压器的微机差动保护原理进行分析,解释在实际工作中高压侧CT二次线两相换位造成差动保护误动的原因。

Microcomputer protection is abstract, especially for transformers with Y and D wiring. There is a phase difference between the high and low voltage side currents, and the differential protection is a split phase differential. It is necessary to perform angle error compensation correction on the high and low voltage side current phase. The principle of the microcomputer differential protection of Yd-11 connection group transformers is analyzed, and the reason for the misoperation of the differential protection caused by the two-phase transposition of the high-voltage side CT secondary line in actual work is explained.