Method and apparatus for determining resistances in multiphase transformer using multiple injected currents in respective windings

Abstract

A method (60) for determining resistances (R1, R2, R3, RN) on a voltage level of a multiphase transformer (10) comprising one winding (u, v, w; U, V, W) for each phase comprises injecting a particular first current into the particular winding (u, v, w; U, V, W); recording a particular first voltage caused by the injected first currents in the plurality of phases; injecting a particular second current into the particular winding (u, v, w; U, V, W), wherein the particular injected second current differs from the particular injected first current in at least one of the plurality of phases; recording a particular second voltage caused by the injected second currents in the plurality of phases, and determining the resistances (R1, R2, R3, RN) on the voltage level on the basis of the injected first and second currents and the recorded first and second voltages. An apparatus (70) for determining resistances (R1, R2, R3, RN) on a voltage level of a multiphase transformer (10) is also proposed.

Dependencies are inferred from the claim text.