Calculation of transformer core losses with nonlinear loads

This paper presents an analytical method to calculate the core losses in a distribution transformer supplying nonlinear loads. The distribution of flux in the core is derived using the magnetizing voltage obtained from a series of frequency domain harmonic equivalent circuits. The flux which contains harmonics is then used to calculate the eddy current and hysteresis losses. An approximation is proposed for the B-H relationship. The method is verified by experiments.