Single pole switch leg based multi-port converter with an energy storage

This study presents a new multi-functional control system for a multi-port energy converter that interfaces one bi-directional battery port, one dc input port, and three output ports. Only one single-leg active switching element (a module type can be used) is employed in the system, and hence the single leg requires digital switching signals for a multi-functional operation to regulate output voltages and to simultaneously manage the battery port. The proposed system has buck-boost conversion capabilities to accommodate wide range, various input sources and output loads. In addition, the single leg requires no dead time due to an integrated impedance network, which will improve the system reliability and performance. Furthermore, the proposed structure can charge a battery even when the input and capacitor voltages are much lower than the battery voltage and hence it significantly improves charging behaviours. The proposed multi-functional control strategy and the converter structure are explained in detail. Then the feasibility and performance of the converter are verified both by computer simulations and experiments based on the Texas Instruments TMS320F28335 digital signal processor.