Transient analysis of magnetodynamic systems using Fourier transform and frequency sensitivity

This paper presents a new efficient method for transient state analysis in magnetodynamic systems of linear eddy current problems. This method employs the Fourier transform and the high-order frequency sensitivity of the harmonic finite element method. By taking into account the time-constant of the magnetodynamic system, the Fourier integral of continuous frequency is converted into the Fourier series of discrete frequency. With the results of Fourier series expansion of converted input waveform, the responses of each sinusoid are superposed to give the total response of the magnetodynamic system. But, if the frequency band of input waveform is broad, it takes a long computational time since all responses for each sinusoid must be calculated. Therefore, the high-order frequency sensitivity method is employed to estimate the response variation to frequency. The proposed algorithm is applied to an induction heating system to validate its numerical efficiency