Method and apparatus for reduction of ripple current

A ripple current reduction circuit couplable to a polyphase AC voltage source, the ripple current reduction circuit comprising:

• a set of first coupled inductors being inductively coupled on a first common core, each first coupled inductor comprising a respective primary winding having a first end and a second end, and configured to receive at the respective first end a respective phase voltage from the polyphase AC voltage source, and a secondary winding;
• a set of second coupled inductors being inductively coupled on a second common core;
• a set of first capacitors, each first capacitor having a first upstream end and a first downstream end, wherein the set of first capacitors are coupled together at the first downstream end to define a first node;
• and
• a set of auxiliary circuits, each auxiliary circuit corresponding to a respective phase voltage and coupled between the second end of the primary winding of a respective first coupled inductor and the first node, wherein each auxiliary circuit comprises a respective second coupled inductor of the set of second coupled inductors, a respective first capacitor of the set of first capacitors, and the secondary winding of a respective first coupled inductor electrically coupled in series.

A method of reducing a ripple current in a polyphase AC circuit, comprising:

• providing a set of first coupled inductors wound on a first common core, each first coupled inductor having a respective primary winding having a first end and a second end, and a secondary winding;
• arranging the first end of each primary winding of the set of first coupled inductors to receive a respective AC phase voltage;
• providing a set of first capacitors, each first capacitor each defining a respective first upstream end and a first downstream end;
• providing a set of second coupled inductors wound on a common core;
• coupling the first downstream end of each first capacitor of the set of first capacitors together to define a first node;
• and
• arranging a set of auxiliary circuits, each auxiliary circuit corresponding to a respective phase voltage and coupled between the second end of the primary winding of a respective first coupled inductor and the first node, wherein each auxiliary circuit comprises a respective second coupled inductor of the set of second coupled inductors, a respective first capacitor of the set of first capacitors, and the secondary winding of a respective first coupled inductor electrically coupled in series.