Patent ID: 9581637
Date: 2017-02-28
CPC Classifications: G01R

Claim:
1. An apparatus for measuring at least a winding resistance of windings in a delta-connected transformer, comprising: at least a first and a second DC current source connectable each between phase ends of a first and a second leg respectively of a primary side of the transformer; at least a third DC current source connectable between two nodes of a secondary side of the transformer; and at least one of a first or a second voltage measurement device, wherein at least one of a first DC voltage drop on a third leg of the primary side is measurable by the first voltage measurement device or a second DC voltage drop on a leg of the secondary side of the transformer is measurable by the second voltage measurement device, whereby voltages in the transformer are generated in response to a first and a second measuring current applied by the first and the second DC current source to each one of two corresponding legs of the primary side of the transformer and a third measuring current applied by the third DC current source between two nodes of a pair of windings on the secondary side of the transformer, and the winding resistance of the windings in the transformer is determined based on voltage measurements provided by at least one of the first or second voltage measurement device.