Optimal Current Observer for Predictive Current Controlled Buck DC-DC Converter

In digital current mode controlled DC-DC converter, the conventional current sensor is either costly or has low accuracy. Thus, current observer, which could be realized based on digital circuit itself, is an ideal substitute for conventional current sensors. However, the observed current may diverge because of parasitic parameters. In this paper, an optimal current observer is proposed to solve the problem. Employing the optimal current observer based predictive current control, a buck converter, which shows preferable transient response than PID controlled converter is implemented. The effectiveness of the optimal current observer is experimentally demonstrated.