Patent ID: 9537411
Date: 2017-01-03
CPC Classifications: H02M,Y02B

Claim:
1. A flyback active clamping power converter, comprising: an input inductor, a first end thereof is connected to a positive terminal of an input voltage source, wherein an input inductor current flowing through the input inductor operates in a boundary conduction mode; a down-bridge switch, a control end thereof receiving a first control signal, and a first end thereof is connected to a negative terminal of the input voltage source, wherein the down-bridge switch is determined to be turned on or off according to a level of the first control signal; an up-bridge switch, a control end thereof receiving a second control signal, and a first end thereof connected to a second end of the down-bridge switch, wherein the up-bridge switch is determined to be turned on or off according to a level of the second control signal, and the down-bridge switch and the up-bridge switch having a switching frequency; a first energy-storing capacitor, a first end thereof connected to the first end of the down-bridge switch; a clamping capacitor, a first end thereof connected to the second end of the up-bridge switch, and a second end thereof connected to a second end of the first energy-storing capacitor; a resonant inductor, a first end thereof connected to a second end of the down-bridge switch; a magnetizing inductor, a first end thereof connected to the resonant inductor, and a second end thereof connected to the second end of the clamping capacitor, wherein the current flowing through the magnetizing inductor is a magnetizing inductor current; a transformer, having a primary winding and a secondary winding, and the primary winding connected with the magnetizing inductor in parallel, wherein the primary winding and the secondary winding have a mutual inductance effect; an output diode, an anode thereof connected to a first end of the secondary winding; and an output capacitor, a first end thereof connected to a cathode of the output diode, and a second end thereof connected to a second end of the secondary winding, wherein a resonant frequency generated by the resonant inductor and the clamping capacitor in the flyback active clamping power converter is substantially equal to the switching frequency, such that the output diode is able to perform a zero current switching.