PID control method using predicted output voltage for digitally controlled DC/DC converter

This paper proposes PID control method using the predicted output voltage. The objective of this study is to improve the stability of the switching converter. The output voltage of next switching cycle is predicted using previous values. A linear function to sixth-degree function are used as prediction method. Transfer function of the proposed method is derived analytically, and the experiment is conducted for the prototype buck converter. As a result, a quadratic function or a cubic equation is practical. The frequency characteristics of the transfer function of the buck converter using the proposed method has higher phase margin and crossover frequency than conventional, and the usefulness of the predicted control was verified.