Field and circuit calculation of the core losses in the energy-saving small-size induction motor

This paper presents no-load core loss analysis of 3-phase energy-saving small size induction motor supplied by sinusoidal voltage. In field-circuit part the distribution and changes of magnetic flux densities of the motor are computed by using time-stepping FEM. Discrete Fourier Transform is used to analyze the magnetic flux density waveforms in each element of the motor model. Rotational aspect of the field is included by introducing correction to first harmonic of alternating losses. Core losses in each element are evaluated using core loss curve measured on toroidal core at different frequencies. In addition, rapid circuit method is presented. The results are compared with the measurements.