Volume and loss optimization of high frequency transformer for compact switch mode power supply considering corrected waveform factor

A new procedure for optimum design of high frequency transformers is presented. The presented design method is based on a restatement and correction of the traditional transformer design equations to include non-sinusoidal switching waveforms and high frequency skin and proximity effects. In this optimization procedure both electric and thermal effects in the transformer is considered. Wave form of voltage and current, and maximum acceptable temperature rise, are used as input data. The aim of this procedure is the selection of the smallest core that can deliver desired power, and determination of optimum flux density and current density to reach a transformer with high power density and admissible temperature rise. Besides, a well known factor which is called wave form factor is challenged in this paper and a new method is proposed to calculation of it. Finally the validity of proposed method is analyzed under arbitrary waveform