Abstract
In this paper, a digital predictive valley current control is proposed for the 4th order boost converter. Detailed mathematical models of the converter system are formulated and then predictive average, peak and valley current control laws, in terms of valley current, are derived. Stability analysis of average, peak and valley current control, under trailing-edge modulation is carried out in the discrete domain. These investigations show that the average and peak current control schemes, with trailing edge-modulation, are unstable for certain duty ratio's, while the valley current control scheme is stable for all duty ratio's, 0 < D < 1. These theoretical studies are validated through the time-domain simulation studies. Discrete compensator is designed using digital direct design approach in order to realize the load voltage regulation together with the valley current control. Closed-loop performance of the proposed control scheme is simulated for different operating conditions. Experimental results are provided to validate the simulation results and theoritical stability predictions.
