Discrete control for three-level boost PFC converter

This paper presents a discrete control for the three-level boost power factor corrected rectifier (TLB-PFC). Linearized discrete models for both the current loop and for the voltage loop are derived. Then, servo controllers with state feedback are developed and designed using the discrete linear quadratic regulator approach. In addition, a predictive state observer is employed to compensate the delay time associated to the discrete implementation. Furthermore, a detailed description of the logic command that assures half DC bus sharing is described. Finally, experimental results from a 1.5 kW TLB-PFC rectifier are presented to validate the analysis carried out as well as to demonstrate the overall performance of the system.