Adaptive Sliding-Mode Controller for Flyback-Based PV Systems Featuring Constant Switching Frequency

Abstract

This paper proposes a sliding-mode controller to ensure both the global stability and maximum power generation of a photovoltaic system based on a flyback converter. The controller is based on an adaptive sliding-surface, which is designed to impose a constant frequency to the switching converter, thus simplifying the selection of both the passive and active elements of the device. Moreover, the controller stability is analyzed using the transversality, reachability and equivalent control conditions. The solution also includes an auto-tuning process for the parameters of the perturb and observe algorithm, which are calculated to ensure the global stability of the sliding-mode controller, thus ensuring the PV system stability. Finally, the performance of the complete solution is verified using detailed circuital simulations of a realistic application case.