A Hybrid Energy System Using Cascaded H-bridge Converter

Different circuit configurations have been researched to combine clean energy sources and energy storage elements. This paper proposes a hybrid energy system to integrate the variable-speed wind turbine, fuel cell, and battery using a cascaded H-bridge converter. One of the advantages of this topology is that it still can obtain the regulated output voltage if one or more energy sources are diminished. In addition, the topology can be easily extended to connect more sources without increasing the circuit and control complexity; therefore, it is beneficial for distributed energy generation. Different operation modes are analyzed in detail. The control schemes were developed to extract maximum wind power and charge/discharge the battery with fast dynamics. The simulation and experimental results are provided to confirm the theoretical analysis.