Comparison of measured and analytically calculated stray load losses in standard cage induction machines

Abstract

An analytical approach to calculate the stray load losses of cage induction machines at sinusoidal supply is compared with input-output measurements according to IEC 61972, which complies with the new standard IEC 60034-2, 4.0 ed. under preparation. The analytical approach allows the calculation of losses in the stator winding due to current displacement, due to harmonic rotor and inter-bar currents, due to tooth flux pulsations and eddy currents in the rotor surface, at any given slip, load and saturation level. Calculation and measurements are compared for 4-pole TEFC standard induction motors 1.1 kW, 11 kW, 75 kW and 110 kW.