A Multi-Source DC/AC Converter for Integrated Hybrid Energy Storage Systems

Hybrid energy storage systems are developed in various applications to integrate high-energy battery packs and high-power ultracapacitor banks. Multi-source inverters are used for the active control of energy sources in hybrid energy storage systems. Due to the magnetic-less topology of the multi-source inverters, the weight, volume, and power losses of the hybrid energy storage systems are reduced, while keeping similar performance. In this paper, a multi-source inverter is developed for the integration and active control of a high voltage DC source and a low voltage DC source, such as battery packs and ultracapacitor banks in energy storage system applications. The topology of the proposed multi-source inverter has a lower number of switching devices compared with the previously presented counterparts. Moreover, the number of conducting switches is reduced, which results in reduced power losses and improved efficiency. A closed-loop current controller is utilized to validate the proper operation of the proposed multi-source inverter topology. A proper space vector modulation technique is implemented to generate appropriate switching pulses during all operating modes. The performance of the proposed multi-source inverter is verified through simulations on PSIM software and experiments on a laboratory prototype.