A One-Inductor Two-Switch Three-Port DC-DC Converter for PV-Battery Systems

The increasing demand for photovoltaic battery systems with low cost, high reliability, and high efficiency drives the requirement for efficient and compact three-port converters (TPCs), necessitating simpler topologies and a reduced number of components. In this paper, a new TPC topology based on one inductor and two switches was proposed. Only one inductor, two switches, and two diodes are required by this topology, resulting in a reduction in the number of components from 7 to 5, corresponding to a reduction of 29%, thereby decreasing the system size and cost. The operating modes and states of the proposed topology were analyzed theoretically, and its feasibility was verified through simulations and experiments. Experimental results demonstrated that the efficiency of the topology reached 89%, 95.3%, and 91% under SIDO, DISO, and SISO operating states, respectively. Compared with the existing TPCs, the proposed topology was found to possess advantages of a simpler structure and a reduced number of components, making it suitable for applications where common ground is not required and strict cost limitations are imposed.