Control design optimization for an asymmetric half-bridge converter

This paper presents control design optimization for an asymmetric half-bridge (AHB) converter with current-doubler-rectifier (CDR) for high-performance airborne applications. An accurate dynamic model will be first developed by taking into account the zero-voltage switching transition. Input voltage feedforward control is used to improve line regulation. A simple linear feedforward control law is developed to linearize the complex nonlinear dc voltage transfer function. Placement of the output EMI filter and its effects on output impedance as well as voltage feedback control loop design are studied, and an optimized design with the EMI filter included in the voltage loop is presented. The analysis and design are validated by simulation and measurement results of a 2 kW module.