A Partly-Isolated Three-Port DC-DC Converter for Hybrid Energy Storage Applications

In this paper, a novel partly-isolated three-port DC-DC converter (PITPDC) for hybrid energy storage system is proposed. The simplified system architecture leads to reduced cost and size by integrating battery and supercapacitor into the converter. Power distribution and optimization among multiple ports are achieved by the double phase-shift modulation strategy. The operating principle of the converter is analyzed, and its operation in different operating modes is discussed in details. The relationship between transmitted power and modulation parameters of each port is obtained. The experimental results demonstrate that the modulation parameters of the PITPDC can be adjusted to realize effective power distribution among different ports while maintaining the same output power. The proposed PITPDC enhances the flexibility and stability of the energy storage system and provides an effective technological solution for the integration of renewable energy and energy storage systems.