NOVELTY - The structure has a direct current power source (Ed) whose input side is connected with an anode of a filtering energy storage capacitor (Cd) and one end of capacitor (C2). One end of primary winding of a transformer (T) is connected with cathode of filtering energy storage capacitor. One end of secondary winding of transformer is connected with anode of diode (D3) while the other end is connected with one end of filtering capacitor (C3) as cathode of converter. A cathode of diode (D3) is connected with other end of filter capacitor (C3) as an anode of converter between points (A,B).    USE - Flyback topology structure of electric power converter such as direct current (DC)-DC converter and DC-alternating (AC) converter used in photovoltaic power generation plant, wind power generation plant, fuel cell power generation plant, and communication power supply.    ADVANTAGE - The semiconductor switch devices are turned on and off at zero voltage. The power diodes are connected in parallel, so that the voltage electric current stress is reduced, switch loss of semiconductor device is reduced and electromagnetic interference is reduced. The conversion efficiency of converter is increased and electromagnetic interference of capacitor is restrained.    DETAILED DESCRIPTION - A source of a semiconductor switch device (V2) is connected with an anode of a diode (D2). Other end of capacitor (C2) is connected with cathode of a diode (D1). A drain electrode of the semiconductor switch device (V1) is connected with a connecting point (A). A source electrode of semiconductor switch device (V1) is connected with an anode of a diode (D1) and other end of primary winding of transformer. A drain electrode of a semiconductor switch device (V2) is connected with cathode of diode (D2) connected with a connecting point (B). An INDEPENDENT CLAIM is included for control method of electric power converter.    DESCRIPTION OF DRAWING(S) - The drawing shows a circuit diagram of the flyback topology structure of electric power converter. (Drawing includes non-English language text)    Connecting points (A,B)    Capacitor (C2)    Filtering capacitor (C3)    Filtering energy storage capacitor (Cd)    Diodes (D1-D3)    Direct current power source (Ed)    Transformer (T)    Semiconductor switch devices (V1,V2)