SINGLE-ENDED FORWARD-FLYBACK CONVERTER Russian patent published in 2022 - IPC H02M3/335 

FIELD: electrical engineering.

SUBSTANCE: invention relates to the field of electrical engineering, including switching power converter technology, and is intended for use as a secondary power source with adjustable output voltage and increased efficiency for supplying DC loads in the presence of primary autonomous or network-wide sources of direct or alternating current. The effect is ensured by the fact that in the proposed invention, in parallel with the first primary windings of the first and second transformers connected in series, a chain of series-connected intermediate capacitor and shunt diode is connected. When the semiconductor switch is opened, a current flows in a circuit consisting of series-connected first primary windings of transformers, an intermediate capacitor and a shunt diode, which is supported, among other things, by the energy stored in the leakage inductances of the first primary windings of the first and second transformers. In this case, the capacitor accumulates this energy, and the voltage across it increases. In order to increase the efficiency of the converter due to the beneficial use of the energy stored in the capacitor, the second primary windings of the first and second transformers connected in series are additionally introduced into the circuit. Through these windings, the energy stored in the capacitor is partly transferred to the secondary side to the load, and partly regenerated into the primary DC voltage source. In addition, the shunt diode provides at the pause stage (when the semiconductor key is open) the return of the transformer cores to their original magnetic state without overvoltages on the key. The decrease in voltage ripple at the load will be facilitated, firstly, by the double frequency of energy pulses that recharge the filter output capacitor, compared with the control frequency of the semiconductor switch, and, secondly, by the increased intensity of these pulses entering the secondary side of the load as at the stage of a closed circuit. , and at the stage of the open state of the semiconductor key from the first and second primary windings of the first and second transformers.

EFFECT: invention provides the possibility of increasing the efficiency due to the beneficial use of the energy accumulated in the leakage inductance of transformers, and at the same time eliminating overvoltages on semiconductor switches, as well as the possibility of improving performance, in particular, reducing voltage ripple on the load, as well as eliminating the need to take measures to remagnetize transformers.

4 cl, 1 dwg