Multiple Frequency Shifting and Its Application to Accurate Multi-Scale Modeling of Induction Machine

The use of the shift frequency as a simulation parameter has been widely acknowledged as an enabler for multi-scale modeling of electrical power systems. So far, the frequency shifting concept has been applied to modeling electrical components considering one shift frequency. This letter aims to complement the previous work and present a multiple-frequency shifting modeling methodology. The methodology is applied to the high-slip induction machine. Two major achievements are introduced: 1) Application of frequency shifting concept for components considering multi-carriers. The Fourier spectra of machine stator and rotor quantities are shifted by different shift frequencies. 2) Modeling of components with time-varying shift frequencies. The frequency shifting modeling methodology is so extended to a wider application area. Case studies are included to demonstrate the effectiveness of the proposed method and the developed machine model.