Sampled-data modeling and digital control of resonant converters

Abstract

A sampled-data model to describe the dynamics of large signals and of small perturbations away from a cyclic steady state is developed. Associated transfer functions are obtained. The application of the model is illustrated by correlating the analysis with simulation results obtained for a series resonant DC/DC power converter. A discrete-time microprocessor-based controller, designed using the aforementioned dynamic model, has been built and tested using a simulation for a series-resonant DC/DC converter set up on the Massachusetts Institute of Technology Parity Simulator. The control methods implemented are state feedback and periodic output feedback, each designed to achieve a specified set of closed-loop poles. The controller has been implemented using the Parity Simulator generalized controller. Results of the closed-loop response showed an improvement over the open-loop response. In addition, the effect of the microprocessor computation delay on the closed-loop dynamics of the converter is investigated.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>