A modeling and closed-loop control method for DC-DC PWM converters by local average techniques

A method of modeling and control of DC-DC static power converters, under continuous conduction mode (CCM) and discontinuous conduction mode (DCM) is presented in this paper. This method is oriented to the discrete time closed-loop predictive-adaptive control, based on local average techniques. The basis consists in the generation of an averaged converter model in state-space form. This is the starting point to make the difference equation formulation that will be later transformed in the control algorithm. The coefficients of the model are periodically updated by means of real state variables measurements. By using this procedure, an excellent transitory response, and also a remarkable robustness against disturbances and strong load changes, are obtained. The method is applied to a buck-boost converter with pulse-width modulation (PWM) and the paper finishes showing some comparative results obtained by PSPICE simulation