Parallel-connected buck-boost converter with FLC for hybrid energy system

Abstract

The control of renewable energy sources is more complicated when used as hybrid energy systems. Power electronic circuits are used to convert and store the electrical energy generated from renewable energy sources. However, the high frequency switching in these power electronic circuits complicates the control of the systems. Advanced control methods are required to control such complex systems. In this study, a hybrid energy system was devised and implemented experimentally to first convert the solar and wind energy to electrical energy and, then to store and use it through a common bus voltage. The study focused on buck-boost converters' parallel connection and deviations from the common bus voltage level were taken into account. The converter system's control was tested with FLC as the best solution, and the results obtained from simulation and experiments were compared. The experimental setup was controlled with a fast and real-time digital signal processor (DSP). Current and voltage measurement circuits, MOSFET drivers, and parallel-connected buck-boost converters were realized experimentally. The simulations and experimental results were suitable for various solar and wind conditions. This hybrid system was also tested at low solar radiation and at low wind speeds to stabilize common bus voltage and energy harvesting.