Iron Losses in Electrical Machines Due to Non Sinusoidal Alternating Fluxes

This paper shows how the flux waveform in the core of an electrical machine can be vary non- sinusoidally which complicates the calculation of the iron loss in a machine. A set of tests are conducted on a steel sample using an Epstein square where harmonics are injected into the flux waveform which vary in both magnitude and phase. The measurements are put forward to illustrate the additional iron losses. Further work is suggested so that a set of linear approximations or interpolation of look-up tables can be used to calculate the iron loss from an analytical of finite element analysis of a machine.