DSP based implementation of an input/output feedback linearization control technique applied to a three-phase three-level neutral point clamped boost rectifier

In this paper, a new control strategy for a three-phase three-level neutral-point-clamped boost rectifier is designed and implemented. It consists of applying a nonlinear feedback linearization technique. The nonlinear state space model of the rectifier was obtained in (d,q,0) reference frame using the power balance between the input and output sides. The input/output feedback linearization is then applied and the linearizing control law is derived. Hence, the resulting model is linearized and decoupled. Afterward, the tracking controllers are designed based on linear techniques to control THD line-currents, power factor, output and neutral point voltages. This control uses a 1.8 kHz pulse width modulator. Experimental results based on the use of DS1104 DSP of DSPACE verify the robustness of the proposed control law in both balanced and unbalanced output load conditions. The line-current THD and output voltage ripples are very low. The settling time and the overshoot are notably small in comparison with standard PI controller.