The three-phase transformer comprises three separate single-phase transformers with shared limbs, each representing a phase consists of primary and secondary windings. The primary or secondary windings are connected in one of several ways. The most common configurations are the star, delta, and Zigzag. The phase angle between the high voltage and the low voltage windings varies between 0o and 360 o. The vector group is the method of categorizing the high voltage HV windings and low voltage LV windings configurations of three phase transformers [1]. The vector group of a transformer is presented as follow: Fig.1. Vector Group Representation THE IMPORTANCE OF THE TRANSFORMERS VECTOR GROUP DETECTION. The transformers vector group identification (Y-Y, Delta-Y, Delta-Delta… etc.) is an essential [...]