A New Digital Control Algorithm to Achieve Optimal Dynamic Performance in DC-to-DC Converters

In this paper, a new optimal control algorithm is proposed to achieve the best possible dynamic performance for DC-to-DC converters under load changes and input voltage changes. Using the concept of capacitor charge balance, the proposed algorithm predicts the optimal transient response for a DC-to-DC converter during the large signal load current change, or input voltage change. The equations used to calculate the optimized transient time and the optimized duty cycle series are presented. By using the proposed algorithm, the best possible transient performance, including the smallest output voltage overshoot/undershoot and the shortest recovery time, is achieved. In addition, since the large signal dynamic response of power converters is successfully predicted, the large signal stability is guaranteed. Experimental results show that the proposed method produces much better dynamic performance than a conventional current mode PID controller