Grid-Interface Bidirectional Converter for Residential DC Distribution Systems-Part 2: AC and DC Interface Design With Passive Components Minimization

With the emerging installations of multitype renewable energy sources and energy storage elements, the dc electronic distribution systems in residential houses/buildings (dc nanogrid) are becoming an alternative future system solution, achieving a zero net-energy consumption and optimized power management. One of the critical components in such a dc system is the grid-interface bidirectional ac-dc power converter, namely the energy control center. Besides, the basic power conversion function, the system interface solution in grid-interface converter is important to successfully interconnect the ac and dc systems as well as fulfill the power quality and EMI regulation codes on both dc and ac sides. This paper presents a complete discussion of several aspects of system interface design for the grid-interface converter under both single-phase and three-phase system conditions. A passive plus active filter solution is proposed to accomplish the common-mode-related noises minimization as well as a dramatic reduction of the converter system volume.