New transfer function model for PWM power converter

Abstract

An equivalent circuit for a power converter bridge leg is derived. In this circuit model the PWM (pulsewidth modulation) power switches are represented by dependent power sources. By this approach PWM switching converters can be represented by a continuous, but nonlinear, electric circuit. By making reasonable assumptions, a linear transfer function model for the power converter is developed. The root locus method is used to analyze the dynamic performance of the inverter. The accuracy of the transfer function model is examined. A single-phase bridge inverter is used as an example.<>