PI Passivity-Based Control for a High-Gain Step-up Converter

This paper presents a multi-loop nonlinear control strategy applied to a DC-DC high-gain active switched-inductor boost converter. The topology of the system is based on the conventional boost converter plus an Active Switching Inductor array. Hence, it comprises two inductors and two power semiconductor devices, leading to an increased output voltage conversion ratio while maintaining acceptable duty cycle limits compared to the traditional DC-DC boost converter. To operate the proposed converter, a simple, robust, and easy-to-tune proportional-integral passivity-based control strategy is developed for the inner current loop. Additionally, an outer voltage loop is designed with a standard proportional-integral action to provide the current reference. The proposed control scheme overcomes the non-minimum phase behavior present in step-up converters and ensures the asymptotic stability of the closed-loop. The performance and effectiveness of the proposed controller are evaluated under numerical simulations, where two scenarios are considered: changes in the output load and changes in the input voltage.