Integrating Photovoltaics and Battery Energy Storage to Grid Using Triple Active Bridge and Voltage Source Converters

Triple active bridge converters are an extension of dual active bridge converters and used to combine multiple energy sources. The advantages of using a triple active bridge converter are its high power density, providing isolation along with elimination of low frequency transformer and high efficiency power conversion. To address the intermittent nature of solar energy, it is always appropriate to include a energy storage device along with it. Triple active bridge converter acts a viable option in integrating these two energy sources in the most efficient manner. Further, this energy can be fed to the grid by using a voltage source converter cascaded with this triple active bridge converter. This paper discusses the cascaded converter with its control algorithms and different operating modes. A laboratory prototype of a triple active bridge converter integrated with the grid through a voltage source converter is developed and the different control and operating modes are verified, which are also included in this paper.