Analytic Model Inclusive Transformer for Resonant Converters Based on Extended Fundamental Frequency Analysis for Resonant Converter-Design and Optimization

Abstract

The series-parallel resonant converter and its magnetic components are analysed by extended fundamental frequency techniques. The proposed model allows an easy design of the resonant circuit and the integrated transformer and the calculation of the losses of all components of the converter. The purpose of the presented analytic model is an optimisation of the converter system—minimising either the volume/power density or the losses of the converter (restriction: temperature rise). Moreover, the presented equations also include a ZCS condition for one leg of the converter, the control of the converter by the frequency and duty cycle and a load model with offset voltage. The proposed analytic model is validated by simulation as well as by experimental results.