一种基于同名相的主变差动保护判向方法探究

Research on a Direction Determination Method for Differential Protection of Main Transformer Based on Phases with the Same Name

本文提出一种基于主变差动保护各侧同名相电流的二次回路判向方法。该方法测量主变差动保护各侧同名相的相电流,应用文中提出的关于相角和差流值的两个算法判据,基于两卷及三卷主变两个案例的实测数据开展分析,进行主变差动保护各侧电流回路CT极性与CT变比二次接线正确性的判定,该方法简单易行且判据明确,可广泛应用。

A direction determination method of secondary circuit based on the same phase currents on each side of the main transformer differential protection is proposed in this paper.The proposed method measures the phase currents of the same phase on each side of the differential protection of main transformer.Based on the measured data of two cases for main transformers with two-coil and three-coil,the two algorithmic criteria for phase angle and differential current values proposed in this paper are used to determine the correctness of CT polarity and CT transformation ratio secondary wiring of the current loops on each side of the differential protection of main transformer.This method is simple and feasible with clear criteria,which can be widely used.