Ohmic losses calculation in SMPS transformers: numerical study of Dowell's approach accuracy

The paper compares two methods for ohmic losses calculation in switch-mode power supply transformers: Dowell's 1D approach and 2D finite element method simulations (validated by measurements). Dowell's method underestimates losses at the fundamental frequency for foil windings, whereas harmonic losses are generally overestimated (depending on conductor type). More significant differences are found with high leakage inductance transformers.