Analysis and Design of Second-life Hybrid Battery Energy Storage System Based on Novel Modular Cascaded Dual-buck DC Converter for Photovoltaic System

A novel modular cascaded dual-buck DC converter which can be applied in Second-Life Hybrid Battery Energy Storage System is proposed. In order to suitably integrate and control these widely different batteries, a suitable multi-modular converter topology is required. A new type of boost converter is proposed, on the front end of each module. It is adapted to the working conditions of various second-life batteries, and it can be used as equipment and the interface of those batteries. The novel proposed boost converter has a higher efficiency compared with the traditional boost converter. The cascaded dual-buck DC converter has been used in this paper. This converter can flexibly connect each module and improve the output voltage. A brief discussion of the general operating principle of the topology is given. Therewith, the advantages of the structure compared with the conventional DC converter are introduced. Finally, simulation with 5kW system is given to prove the theoretical analysis and simulating feasibility of the proposed DC converter.