Operation Performance and Control Strategy Analysis of a Partially Isolated Three-port Converter with Flexible Power Flow Paths

In this paper, a novel partially isolated threeport converter is proposed, and its operating performance and control strategy are analyzed in detail. This converter is suitable for renewable energy power supply system, with flexible power flow paths and compact structure, and can realize power transfer between any ports. Under the proposed control strategy, the converter can automatically adjust the power transfer mode according to the status of each port, which exhibits good fault-tolerant operation capability. Meanwhile, by using phase-shifted pulse-width modulation (PWM) strategy, zero-voltage switching (ZVS) of all switches in different power transfer modes can be achieved, which effectively reduces power loss. The operating principle, control strategy and zero-voltage switching characteristics are discussed in more depth. Finally, the verification results based on PLECS software fully validate the feasibility and correctness of the proposed method.