Analysis of Ferrite Core Loss Under Multi-level Stair Voltage Excitation Considering the Voltage Sequence

The accurate calculation of core loss is very significant for the optimal design of magnetic component such as inductor and transformer. Core loss under sinusoidal and rectangular voltage excitations can be calculated by empirical formulas. However, the magnetizing voltage of magnetic core in practical applications may be multi-level stair wave. The ferrite core loss under multi-level stair voltage excitation is dependent on the voltage sequence, which is against the traditional empirical equations or loss separation formulas. In this paper, the multi-level stair voltage excitation condition is introduced. The dependence of ferrite core loss under multi-level stair voltage excitation on the voltage sequence are investigated. Traditional empirical equations cannot accurately estimate the core loss under multi-level stair voltage excitation. Novel core loss mechanism and estimation method are needed for multi-level stair voltage excitation.