A generalized dynamic transformer circuit model including all types of core losses

This paper describes a generalized dynamic transformer circuit model that includes all types of core losses, nonlinear magnetic characteristics, skin effects of eddy currents in the core, and thermal effects on hysteresis of core materials. A TLM-based transform with variable time steps is employed in the simulation. This model can provide an accurate prediction of transformer performance and core losses and is suitable for simulation of high frequency switching mode converters using transformer isolated outputs. Some interesting issues such as stray capacitance, are discussed. Simulations of a 500 W transformer in a full bridge inverter operated at 15 kHz and 25 kHz have been confirmed by experiments.