Magnetizing Current, Iron Losses And Forces Of Three-Phase Induction Machines At Sinusoidal And Nonsinusoidal Terminal Voltages. Part I: Analysis

Currents, losses, winding and iron core forces at no-load of saturated three-phase induction machines are determined based on a nonlinear magnetic field analysis. Instantaneous magnetizing currents are calculated for given balanced sinusoidal and nonsinusoidald- terminal voltages. Subsequently, the harmonic components of the magnetizing current and the induced voltage are obtained from a Fourier analysis. The coreloss- current component is derived from the sum of local core losses and the no-load current is then iteratively obtained from the sum of the magnetizing and the coreloss- current components. Finally, the calculation of winding and iron-core forces is derived from surface integrals. Part II deals with the results that are based on this analysis.