Thermal study of induction motors by phantom loading using multi-slice time stepping finite element modeling

It is difficult to test large induction motors without expensive facilities or suitable loading. This paper reports the findings in an attempt to assess the thermal properties of commercial induction motors by injecting phantom load currents into the windings. A multi-slice 2-D time stepping finite element model is used to analyze the loss distributions in the machine with phantom loading and with normal direct loading. It can be shown that the high-order harmonic losses in the motor can be precisely estimated with the proposed method. Both experimental and simulation results confirm that phantom loading can be used as substitutes of direct full-load temperature-rise test of induction motors.