Sliding Mode Control of a Cascade Boost Converter for Fuel Cell Energy Generation System

Abstract

In recent years, the renewable energy sources are used as an electric source to reduce energy demand and environmental pollution which occurred using fossil fuels. Fuel cell which is one of the renewable energy sources, and especially Proton Exchange Membrane fuel cell (PEMFC) is a good candidate to solve this problem because it has low emission, high efficiency, perfect part-load performance, and wide size range. This paper deals with the problem of controlling a DC–DC cascade boost converter which is used as a power block for energy conversion system of fuel cell electric vehicle. Using a sliding mode technique, the power converter is controlled in order to achieve two objectives: (i) tight regulation of DC voltage and (ii) asymptotic stability of the closed-loop system. It is worth noting that the nonlinearity of the PEMFC characteristic is taken into account in this work by considering a polynomial approximation of the V–I curve. Moreover, the dynamic model of DC–DC cascade boost converter is analyzed and simulated. It is shown using theoretical analysis and simulations that the controlled system satisfies all the objectives.