Design of a Robust PWM Power Amplifier Using Approximate 2-Degree-of-Freedom Integral Type Control

Abstract

A method is proposed for designing a robust controller for PWM power amplifiers, which are widely used as amplifiers themselves and power supplies. The main technical requirements imposed on PWM power amplifiers are linerarity in wide frequency range and well-damped fast dynamic response against extensive load and d. c. power supply variations. Therefore, in order to satisfy the design specifications-linearity in wide frequency range and no overshoots during the transients, an approximate 2-degree-of-freedom integral type control structure is proposed as well as a design procedure for the robust controller is discussed. It is clarified from some simulations and experiments that the designed controller shows highlighted good dynamic performances and effective disturbance rejection properties against external disturbances, i. e. load and power-supply variations.