Discrete-time control for DC-AC converters based on sliding mode design

A discrete-time linear state-feedback controller with feedforward compensation is presented for the design of voltage source DC-AC converters. The proposed algorithm is based on duty-ratio control and is obtained by modifying an existing sliding mode design method. It does not introduce chattering in the output waveforms, and its robustness with respect to parameter variations is enhanced by introducing an integral action. An intuitive approach for the selection of the controller parameters is developed. The design criteria are illustrated with reference to a laboratory prototype by means of various experiments, intended to test both stationary and dynamic performance.