Patent ID: 7969265

Claim:
A transformer comprising: first, second and third magnetic cores; a first winding on the first magnetic core and having a first terminal configured to provide a first AC phase connection; a second winding on the second magnetic core and having a first terminal configured to provide a second AC phase connection; a third winding on the third magnetic core and having a first terminal configured to provide a third AC phase connection; a fourth winding on the first magnetic core and having a first terminal connected to a second terminal of the third winding and a second terminal configured to be connected to an AC neutral; a fifth winding on the second magnetic core and having a first terminal connected to a second terminal of the first winding and a second terminal configured to be connected to the AC neutral; a sixth winding on the third magnetic core and having a first terminal connected to a second terminal of the second winding and a second terminal configured to be connected to the AC neutral; a seventh winding on the first magnetic core and having a first terminal connected to the first terminal of the first winding; an eighth winding on the second magnetic core and having a first terminal connected to the first terminal of the second winding; a ninth winding on the third magnetic core and having a first terminal connected to the first terminal of the third winding; a tenth winding on the first magnetic core and having a first terminal connected to a second terminal of the ninth winding and a second terminal configured to provide a fourth AC phase connection; an eleventh winding on the second magnetic core and having a first terminal connected to a second terminal of the seventh winding and a second terminal configured to provide a fifth AC phase connection; and a twelfth winding on the third magnetic core and having a first terminal connected to a second terminal of the eight winding and a second terminal configured to provide a sixth AC phase connection.