NOVELTY - The converter (1) has an output circuit (107) electrically connected to an auxiliary circuit (105). A closed-loop controller (109) is electrically connected to power source circuits (101, 103), the auxiliary circuit and the output circuit. The controller controls duty cycles of two switches (S1, S2) and an auxiliary switch (Sa) based on a feedback signal (Sf) and a command signal (Sc) such that the two switches and the auxiliary switch are switched at zero voltage. The controller controls switching of power switches (Sp1, Sp2) such that power sources (V1, V2) are connected or cut off.    USE - Dual-source converter for use in a hybrid generation system to generate renewable energy to operate a power source e.g. secondary cell, super capacitor, fuel cell, solar cell and wind turbine such as direct current (DC) wind turbine and rectified alternate current (AC) wind turbine (all claimed), in a vehicle, an uninterruptible hybrid power supply and an independent generator.    ADVANTAGE - The auxiliary circuit achieves soft switching of the switches. The closed loop controller controls the duty cycles of the power circuits and the auxiliary circuit so as to improve efficiency of the converter. The converter executes soft switching with low loss in turning on. The converter effectively increases total conversion efficiency and reduces cost of building the hybrid generation system. The power sources at different voltages are connected to each other in series and converted to a stable power source, and the converter can be switched between a single-source mode and a dual-source mode such that the converter effectively reduces loss in turning on and increases conversion efficiency in the dual-source mode. The auxiliary circuit can be used to switch the switches at zero voltage to achieve flexible switching. The inductor current in the converter continues to travel to effectively filter out current ripples, thus avoiding damages of a device operated on renewable energy.    DESCRIPTION OF DRAWING(S) - The drawing shows a circuit block diagram of a dual-source converter.    Auxiliary switch (Sa)    Command signal (Sc)    Feedback signal (Sf)    Power switches (Sp1, Sp2)    Switches (S1, S2)    Power sources (V1, V2)    Dual-source converter (1)    Power source circuits (101, 103)    Auxiliary circuit (105)    Output circuit (107)    Closed-loop controller (109)