Power conversion device

A power conversion device comprising:

• a converter including a main switch element, a main rectifying element, an output capacitor, and a primary winding of a coupled inductor, the polarity of a current of the primary winding switching between positive and negative states;
• and
• a resonance assist circuit based on a closed-loop circuit,
• wherein the closed-loop circuit includes
• a first series circuit having a secondary winding of the coupled inductor, a first rectifying element, and a first auxiliary switch that is driven when the polarity of the current of the primary winding is positive;
• a second series circuit having a tertiary winding of the coupled inductor and a second rectifying element;
• and
• a first auxiliary capacitor connected to the first series circuit and the second series circuit,
• wherein the secondary winding and the tertiary winding are separate bodies and the first series circuit and the second series circuit are connected in parallel to the first auxiliary capacitor or the tertiary winding is integrated with the secondary winding,
• wherein the closed-loop circuit further includes
• a third series circuit having a third rectifying element, a second auxiliary switch that is driven when the polarity of the current of the primary winding is negative, and the secondary winding;
• a fourth series circuit having the tertiary winding and a fourth rectifying element;
• and
• a second auxiliary capacitor connected to the third series circuit and the fourth series circuit and connected to the first auxiliary capacitor, and
• wherein the secondary winding and the tertiary winding are separate bodies and the third series circuit and the fourth series circuit are connected in parallel to the second auxiliary capacitor or the tertiary winding is integrated with the secondary winding.

A power conversion device comprising:

• a converter including a main switch element, a main rectifying element, an output capacitor, and a primary winding of a coupled inductor;
• a resonance assist circuit based on a closed-loop circuit including a series circuit having a secondary winding of the coupled inductor, a first rectifying element, and an auxiliary switch element;
• and
• a controller configured to determine an ON timing of the main switch element using a voltage of an auxiliary winding of the coupled inductor.

A power conversion device comprising:

• a converter including a main switch element, a main rectifying element, an output capacitor, and a primary winding of a coupled inductor;
• and
• a resonance assist circuit based on a closed-loop circuit including a series circuit having a secondary winding of the coupled inductor, a first rectifying element, and an auxiliary switch element,
• wherein the converter is any one of a boost-buck converter, a flyback converter, and a buck converter, and
• wherein the converter is configured to obtain a constant voltage source from a voltage of the secondary winding via a rectifier diode.

A power conversion device comprising:

• a converter including a main switch element, a main rectifying element, an output capacitor, and a primary winding of a coupled inductor, the polarity of a current of the primary winding switching between positive and negative states;
• a resonance assist circuit based on a first closed-loop circuit including a positive-side secondary winding of the coupled inductor, a first rectifying element, and a first auxiliary switch that is driven when the polarity of a current of the primary winding is positive and a second closed-loop circuit including a negative-side secondary winding of the coupled inductor, a second rectifying element, and a second auxiliary switch that is driven when the polarity of the current of the primary winding is negative;
• and
• a controller configured to determine an ON timing of the main switch element using a voltage of an auxiliary winding of the coupled inductor.

A power conversion device comprising:

• a converter including a main switch element, a main rectifying element, an output capacitor, and a primary winding of a coupled inductor, the polarity of a current of the primary winding switching between positive and negative states;
• a resonance assist circuit based on a closed-loop circuit including a secondary winding of the coupled inductor, a first rectifying element connected in parallel to a first auxiliary switch that is driven when the polarity of the current of the primary winding is positive, and a second rectifying element connected in parallel to a second auxiliary switch that is driven when the polarity of the current of the primary winding is negative;
• and
• a controller configured to determine an ON timing of the main switch element using a voltage of an auxiliary winding of the coupled inductor.