A Power Supply System with ZVS and Current-Doubler Features for Hybrid Renewable Energy Conversion

In this paper, a power supply system for hybrid renewable energy conversion is proposed, which can process PV (photovoltaic) power and wind-turbine energy simultaneously for step-down voltage and high current applications. It is a dual-input converter and mainly contains a PV energy source, a wind turbine energy source, a zero-voltage-switching (ZVS) forward converter, and a current-doubler rectifier. The proposed power supply system has the following advantages: (1) PV-arrays and wind-energy sources can alternatively deliver power to the load during climate or season alteration; (2) maximum power point tracking (MPPT) can be accomplished for both different kinds of renewable-energy sources; (3) ZVS and synchronous rectification techniques for the active switches of the forward converter are embedded so as to reduce switching and conducting losses; and (4) electricity isolation is naturally obtained. To achieve an optimally dynamic response and to increase control flexibility,<b> </b>a digital signal processor (DSP) is investigated and presented<b> </b>to implement MPPT algorithm and power regulating scheme. Finally, a 240 W prototype power supply system with ZVS and current-doubler features to deal with PV power and wind energy is built and implemented. Experimental results are presented to verify the performance and the feasibility of the proposed power supply system.