<p>The simulation carried out in this paper presents a model of the digital differential protection relay with a double-slope characteristic also dedicated to the protection of power transformers. The relay model comprises three blocks. The first is dedicated to the elimination of the homopolar component of the windings coupled in (<b>Y</b>) with neutral connected to earth. The second is dedicated to the digital adaptation of the group of vectors of the (<b>Δ</b>) coupling of the windings, while the third is dedicated to the realization of the decision algorithm of the digital relay. To assess the performance of the relay model, this work processes the following stages: An example to be studied involves a transformer comprises a 60 kV star-connected primary winding with a grounded neutral (Yg) and a 30 kV delta-connected secondary winding in the D₁₁ vector group configuration. Next, the elimination of the homopolar component of the windings coupled to the ground is performed, along with numerical adaptation of the vector group of the Star-Delta coupling. After that, a <i>MATLAB</i> function is implemented to solve this problem, enabling the prediction of the decision algorithm and the calculation of adjustment parameters for the model proposed using <i>MATLAB/Simulink</i>.</p>