Research on PV-Storage Complementary Three-Port Converter With Power Decoupling

This article proposes a photovoltaic (PV)-storage three-port converter, which achieves power balancing among three ports by multiplexing six switches, offering flexible power flow control with five operating modes. A four-target control strategy that can achieve PV maximum power point tracking (MPPT), output voltage stabilization, and secondary ripple suppression at the two dc ports is proposed. Through power decoupling, the secondary ripple of the two dc ports are transferred to the bus capacitor, thereby achieving suppression of the ripple. Besides, theoretical analyses of the circuit topology and switching state, control strategy, steady-state characteristics, and high-frequency switching processes are conducted in turn. Based on this, an experimental setup was built to experimentally validate the functionality of the converter. Experimental results demonstrate that the converter can operates effectively under both three-port and two-port status, achieving PV MPPT and two dc ports secondary ripple suppression at the same time, while delivering high-quality ac voltage, showcasing excellent overall performance.