Ferrite core loss measurement with arbitrary wave excitation

This paper studies the methods of loss measurement for ferrite cores under sinusoidal and nonsinusoidal excitations. For the sinusoidal excitation, a resonant method is introduced and the impedance angle of the ferrite inductor under study is reduced to zero, which makes the measurement least sensitive to the influence of parasitic impedance. Hence the accuracy of measured results is increased. For the non-sinusoidal excitation, two-search-coil method is used to study the core losses. By analyzing the voltage and current waveforms observed from these two search coils, the core loss contributed by each harmonic component is determined.