Half-bridge converter including rectifier structure using coupling inductor

An asymmetrical half-bridge converter, comprising a primary-side circuit comprising a first switch, a second switch, a primary-side capacitor, an additional inductor, and a primary-side magnetization inductor,

• wherein a secondary-side circuit comprises:
• a first diode and second diode which are connected in series;
• a first capacitor and second capacitor which are connected in series;
• a secondary-side rectification inductor having one end connected to an anode of the first diode and cathode of the second diode, which are connected in series, and having the other end connected between the first capacitor and the second capacitor which are connected in series;
• a first coupling inductor having one end connected to a cathode of the first diode and having the other end connected to the first capacitor;
• and
• a second coupling inductor having one end connected to an anode of the second diode and having the other end connected to the second capacitor;
• wherein a voltage gain (VO/VS) of the converter is equal to an equation below:
• VO/VS=2DQ1/n
• wherein DQ1 is a duty cycle of the first switch of the primary-side circuit, and n is a turn ratio of the primary-side circuit and the secondary-side circuit.

An asymmetrical half-bridge converter, comprising a primary-side circuit comprising a first switch, a second switch, a primary-side capacitor, an additional inductor, and a primary-side magnetization inductor,

• wherein a secondary-side circuit comprises:
• a first diode and second diode which are connected in series;
• a first capacitor and second capacitor which are connected in series;
• a secondary-side rectification inductor having one end connected to an anode of the first diode and cathode of the second diode, which are connected in series, and having the other end connected between the first capacitor and the second capacitor which are connected in series;
• a first coupling inductor having one end connected to a cathode of the first diode and having the other end connected to the first capacitor;
• and
• a second coupling inductor having one end connected to an anode of the second diode and having the other end connected to the second capacitor;
• wherein zero-voltage switching conditions of the first switch and second switch of the primary-side circuit are equal to equations below, respectively:
• ½Llkg(−2IO/n)2≥COSSVS2
• ½Lm(−2IO/n)2≥COSSVS2
• wherein Llkg is the additional inductor of the primary-side circuit, IO is an output current of the secondary-side circuit, n is a turn ratio of the primary-side circuit and the secondary-side circuit, and Coss is an output capacitor of the primary-side circuit.

An operating method of an asymmetrical half-bridge converter, comprising a primary-side circuit comprising a first switch, a second switch, a primary-side capacitor, an additional inductor, and a primary-side magnetization inductor, and a secondary-side circuit comprising a first diode and second diode which are connected in series, a first capacitor and second capacitor which are connected in series, a secondary-side rectification inductor having one end connected to an anode of the first diode and cathode of the second diode, which are connected in series, and having the other end connected between the first capacitor and the second capacitor which are connected in series, a first coupling inductor having one end connected to a cathode of the first diode and having the other end connected to the first capacitor, and a second coupling inductor having one end connected to an anode of the second diode and having the other end connected to the second capacitor, the method comprising:

• a step in which the first switch of the primary-side circuit is turned on and the first diode of the secondary-side circuit is turned on;
• a step in which the first switch of the primary-side circuit is turned off and the first diode of the secondary-side circuit is turned on;
• a step in which the second switch of the primary-side circuit is turned on, the first diode of the secondary-side circuit is turned on, and the second diode of the secondary-side circuit is turned on;
• a step in which the second switch of the primary-side circuit is turned on and the second diode of the secondary-side circuit is turned on;
• and
• a step in which the second switch of the primary-side circuit is turned off and the second diode of the secondary-side circuit is turned on;
• wherein an average current flowing into the first capacitor and the second capacitor is set to 0 and an average current flowing into the secondary-side circuit becomes 0 regardless of an operation of the switches of the primary-side circuit.