Experimental evaluation of a cascade sliding mode-PI controller for a coupled-inductor Boost converter

This paper describes the experimental results obtained for a cascade sliding mode PI control in a coupled-inductor Boost converter. A non-linear control strategy similar to sliding mode control was designed for the inner loop, while for the secondary control loop an experimentally tuned PI controller is proposed. The main goal of the closed loop system is to regulate the output voltage of the converter. The control was designed starting with a piece-wise complementarity model of the converter. The complementarity framework allows to model uni-directional switches, with the idealized current and voltage of the diodes as “complementary variables”, i.e. variables that are non-negative and such that their product is zero at any time. The experimental results show the robustness of the control strategy under step changes in the input voltage and load.