Integral Sliding Mode Control of a Stacked Interleaved Buck Converter for Electrolyzers Supplied With Renewable Energy Sources

This article presents a novel control algorithm for a stacked interleaved buck converter (SIBC) to supply energy to a proton exchange membrane electrolyzer (PEMEL) in the presence of renewable energy sources. It leverages the main advantages of the SIBC including high voltage conversion ratio, low output current ripple, and the ability to operate in case of electrical circuit failures. The new control law, based on integral sliding mode-based control, offers a significant improvement in the performance for input variation when renewable energy sources are used. The proposed controller exhibits further benefits, such as a faster dynamic response and greater robustness against parameter uncertainties, when compared to traditional PI-based control. Experimental verification is carried out using a PEMEL dynamic electrical equivalent circuit to mimic the real PEMEL performance under different operating conditions. The obtained experimental results demonstrate that the proposed control technique overcomes current limitations in terms of performance usually characterized by PI controllers. Particularly, a faster response is obtained using the proposed controller accounting for the changes in operating conditions for electrolyzers fed with variable renewable energy resources.