MPPT DC-DC Buck-Boost Converter for Off Grid Hybrid Solar-Wind-Battery System in Ikuza Island, Tanzania

Abstract

Ikuza Island in Tanzania faces lack of electricity. Therefore, this paper undertakes to design hybrid renewable energy sources for the island by specifically focusing on the buck-boost converter for the energy conversion from these renewable resources. The design of the bidirectional buck-boost converter for maximum power point tracking in off-grid hybrid renewable energy systems is multifaceted due to the inhomogeneity nature of the renewable energy sources. The bidirectional buck-boost converter, solar PV, wind-based generator, and energy storage system were designed and simulated in MATLAB/Simulink software. The designed system was tested with varying solar irradiance (750 to 1000 W/m²), temperature (20 to 25°C) and wind speed (150 to 157.5 radians/s) at constant load of 260 A while load variation involved varying the load current from 0 to 260 A at solar irradiance, temperature, and wind speed of 1000 W/m², 25 °C and 157.5 radians/s, respectively. The variation of DC link bus voltage at different load conditions was reported. The simulation results show that the designed converter is able to maintain DC link voltage at 600 V. Moreover, the DC link voltage showed a maximum drop of approximately 0.67% during the constant load condition. Contrarily, a significant improvement is observed when the designed converter operates with the hybrid system of solar PV, PMSG-based wind generator and with energy storage system.