Transformer with interleaved shielding windings

A transformer, comprising:

• a first primary winding and a second primary winding;
• a secondary winding being disposed between the first primary winding and the second primary winding;
• and
• a first wire shielding winding and a second wire shielding winding;
• wherein:
• the first wire shielding winding is disposed between the first primary winding and the secondary winding, the second wire shielding winding is disposed between the second primary winding and the secondary winding;
• the first wire shielding winding and the second wire shielding winding are aligned symmetrically on opposite sides of the secondary winding and along a height dimension from a first turn to a last turn of the secondary winding;
• the first primary winding and the second primary winding are serially electrically connected in a primary-side series combination, the primary-side series combination having a first primary-side terminal and a second primary-side terminal;
• the secondary winding has a first secondary-side terminal and a second secondary-side terminal;
• the first wire shielding winding and the second wire shielding winding are serially electrically connected in a shielding series combination at an intermediate shielding terminal, the shielding series combination having a first shielding terminal and a second shielding terminal;
• the first primary-side terminal is configured to be electrically connected to a first primary-side node at a primary-side of a power converter;
• the second primary-side terminal is configured to be electrically connected to a second primary-side node at the primary-side of the power converter;
• the first secondary-side terminal is configured to be electrically connected to a first secondary-side node at a secondary-side of the power converter;
• the second secondary-side terminal is configured to be electrically connected to a second secondary-side node at the secondary-side of the power converter;
• the intermediate shielding terminal is configured to be electrically connected to a third primary-side node at the primary-side of the power converter;
• and
• the first shielding terminal and the second shielding terminal are electrically floating.

A method comprising:

• forming a first primary winding of a transformer;
• forming a first wire shielding winding of the transformer;
• forming a secondary winding of the transformer, the first wire shielding winding being disposed between the first primary winding and the secondary winding;
• forming a second wire shielding winding of the transformer;
• symmetrically aligning the first wire shielding winding and the second wire shielding winding on opposite sides of the secondary winding and along a height dimension from a first turn to a last turn of the secondary winding;
• and
• forming a second primary winding of the transformer, the secondary winding being disposed between the first primary winding and the second primary winding, and the second wire shielding winding being disposed between the second primary winding and the secondary winding;
• and
• wherein a number of wire strands of the first and second wire shielding windings is equal to a first product that is equal to a winding area length multiplied by a bobbin winding window filling factor divided by a second product that is equal to a number of shielding winding turns multiplied by a diameter of the first and second wire shielding windings.