Asymmetric half-bridge flyback power converter and method of operating the same

An asymmetric half-bridge flyback power converter comprising:

• a transformer comprising a primary-side winding, a secondary-side winding, and a magnetizing inductance;
• the primary-side winding coupled to the secondary-side winding, and the magnetizing inductance connected to the primary-side winding in parallel,
• a resonant circuit coupled to the primary-side winding,
• a switching circuit comprising a first switch and a second switch connected in series at a node, and the node coupled to the resonant circuit,
• a zero-voltage switching circuit coupled to the node, and comprising a discharging switch, a diode, and an energy storage capacitor connected in series, and
• a controller coupled to the zero-voltage switching circuit, and the controller configured to control the first switch and the second switch to be turned on or turned off to generate an output voltage,
• wherein when an output energy of the power converter is less than an energy threshold and before the first switch is turned on by the controller, the controller is configured to first turn on the discharging switch so that the energy storage capacitor stores energy to rise a current flowing to the node.