Abstract:

To reduce the effect of disturbances, a nonlinear controller was designed for a DC／DC Buck converter. First, an error model with disturbances was built based on the nonlinear model of a Buck converter. Then an H∞controller and its parameters were deduced based on the passive theory. A theoretical analysis was given to prove the stability of a closedloop control system. Finally, a  numerical simulation and circuit simulation were performed for the case of parametric perturbations of a Buck converter. The simulation results demonstrated the validity and effectiveness of the proposed control strategy.

Key words:  H_∞ control, Buck converter, passive system, parametric perturbation