Digital control of a boost converter using Posicast

Analysis, design, simulation and DSP-based implementation of a digital controller using a Posicast element are presented for the boost converter. Different from the classical Posicast approach, the proposed control method here reduces undesirable sensitivity greatly by using Posicast within a feedback loop. Furthermore, unfavorable effects on system stability caused by the RHP zero and parasitic elements in the boost converter's dynamics can be ignored in the design of controller because of its narrow open-loop bandwidth. Transient and frequency responses are presented. The performance of a Posicast-based controller for a boost converter has been investigated through simulation and verified by experiment. The sensitivity of the system dynamical response to variations in controller parameters was examined. The effect of load resistance variation was also tested.

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