Multiport Power Electronic Interface—Concept, Modeling, and Design

The continuous effort to improve efficiency, reduce particle, and greenhouse gase emissions leads to the emergence of the concept “more electric.” This concept helps to boost the performance as well as the flexibility of the domestic and vehicular applications; however, on the other hand, it excessively burdens current power networks (including vehicle power systems). In order to remedy this problem, simultaneous usage of renewable sources and energy storages is encouraged. A multiconverter system is commonly adopted to process the renewable power in form of distributed generation. However, due to the discrete structure of such systems, power flow and load regulation are coordinated via communication channel, which inevitably reduces the reliability and dynamic response of the system. This paper presents the concept of multiport power electronic interface (MPEI) for renewable energy sources and storages. With a unified modular topology and highly integrated digital control system, controlled quasi-current source is achieved for each input port in both steady-state and transient power-sharing modes. MPEI analysis, modeling, design, and system operation are treated in a systematic manner in this paper. Both power stages and digital control system are implemented for a five-port MPEI. Experiments are conducted under meaningful operation scenarios. The results are presented to prove the feasibility of MPEI concept and system design methodology.