An Isolated Three-Port Power Converter with 2C3L and 2C2L Resonant Circuits

Abstract

This study proposed an isolated three-port bidirectional resonant converter that combines 2C3L and 2C2L resonant circuits for application in power dispatching. The proposed converter improves the bidirectional power dispatch capabilities of conventional three-port converters and utilizes different resonant converters to complete the energy charge–discharge through ports of different voltage levels. By modulating the frequency alone, bidirectional power regulation and electrical isolation were achieved among the three ports with different voltage levels. The converter involves the use of resonance techniques to enable the power switch to perform soft switching during bidirectional power transmissions, reducing switching loss and electromagnetic interference. The system control of the circuit was a Texas Instruments TMS320F28335 microcontroller. By simulating a DC grid port with a fixed voltage of 400 V, a vehicle battery port with a variable voltage of 280–403 V, and a battery charging port with a variable voltage of 180–213 V, an experimental platform with a rated output of 3 kW was built to determine the accuracy of the proposed theoretical analysis and design method.

Keywords

• battery energy charge–discharge
• digital frequency control
• power regulation
• resonant circuits
• three-port power converter
• zero-current switching