A ZVS parallel-series dual-bridge phase-shift DC/DC converter with two degrees of freedom used in hybrid renewable energy power conditioning systems

This paper presents a new two-bridge parallel-series DC/DC converter topology which can operate with ZVS over a wide input and load range. This intended application for this converter is power conditioning systems (PCS) of photovoltaic (PV) arrays used in hybrid renewable energy architectures. The proposed topology provides two degrees of freedom to the converter which enabling it to regulate the DC-link voltage while tracking the maximum power point (MPP) of the PV array. This topology distributes the main power into the two bridges and the phase-shift between the two bridges provides another degree of freedom for the PCS to track the MPP. Since the main power is channeled between the two bridges, the system shows a modular structure which efficiently transfers the power to the load. The proposed converter is also able to achieve soft-switching over a wide range. A 2kW experimental prototype has been provided to validate the feasibility and performance of the converter. Theoretical analysis and experimental results prove that the converter is able to regulate the DC-link voltage and track the maximum power extracted from the PV array simultaneously.