Comparison of lamination iron losses supplied by PWM voltages: US and European experiences

In this paper the behavior of non-oriented laminations when excited with PWM waveforms is analyzed. The USA and the European experiences in core loss measurements with PWM waveforms are compared, highlighting the different experimental approaches and the different test benches. Parameters that characterize a PWM source (i.e. switching frequency, modulation index, modulating waveform type and switching topologies) are varied to ascertain their influence on lamination specific core losses. Although a direct numeral comparison of results was not possible, test results from the two institutions harmoniously show a consistent deterioration of lamination properties when excited with PWM supplies. The problem approach proposed by the two institutions show understanding of core loss measurement methods with non-sinusoidal excitations and can be considered a starting point for future work on a development of a standard procedure for magnetic material characterization with PWM supplies. Test benches with the respective experimental results are detailed in this paper