US Patent No. 10,925,197

ELECTRICAL FILTER FOR RESISTIVELY EARTHED SYSTEMS


Patent No. 10,925,197
Issue Date February 16, 2021
Title Electrical Filter For Resistively Earthed Systems
Inventorship Peter M. Dalton, Grove City, PA (US)
Assignee Joy Global Underground Mining LLC, Warrendale, PA (US)

Claim of US Patent No. 10,925,197

1. An electrical filtering system for use with an industrial machine, the system comprising:a power center including a transformer and a ground fault relay;
a first motor electrically connected to the power center;
a first variable speed drive connected to the first motor, the first variable speed drive configured to vary the speed of the first motor; and
a first common mode choke connected in a series-type connection between the power center and the first variable speed drive, the first common mode choke configured to suppress a ground current induced by the first variable speed drive, wherein the common mode choke includes a plurality of windings, each winding having a first end coupled a power supply line of the power center and a second end coupled to the variable speed drive.