A Grid Connected Battery charger for Renewable Energy Applications

Abstract

The growing concern for renewable energy systems with battery storage has increased the usage of battery-based backup power systems and has gained popularity over recent years because of the rigid environmental criteria on fossil fuels. The demand on plug in battery charger has increased with the necessity of a grid integrated systems in Electric Vehicle (EV) and residential applications. Grid-battery charging techniques can be utilized to enhance renewable systems and their energy management. This work proposes a grid integrated battery charger with a hysteresis controller in the feedback loop. Pulsating charging currents and a power control for the battery pack provides capacity flexibility and lifetime extension. The AC/DC converter is operated with Pulse Width Modulation (PWM), reducing the switching stress and to ensure high efficiency. The operation of the system is analysed and the concept is validated by using MATLAB/Simulink. It is found that the conversion efficiency is approximately 93%, which reveals that with a higher drain-source voltage the system has low losses across converter switches. This procedure provides capacity flexibility and a lifetime extension for the battery energy storage systems.