Analysis and Calculation of T‐Type Equivalent Circuit Parameters of Induction Machines Considering Harmonic Magnetic Field

The accuracy of equivalent circuit parameters plays an essential role in the performance prediction and precise control of induction machines (IMs). A novel equivalent circuit for IMs considering harmonic magnetic field is proposed in this paper based on the finite element method (FEM). Using the two‐dimensional Fourier decomposition, the air gap flux density of the machine are accurately analyzed, and the harmonic components are fully displayed. By means of the frozen magnetic permeability and virtual permanent magnet harmonic machine model (VPMHMM), whose practicality and accuracy have been proven by scholars, the equivalent circuit parameters considering harmonic magnetic fields are calculated in this paper. During the analysis process, the corresponding numerical relationship between circuit parameters and harmonic losses is established, and specific values are estimated by finite element analysis. The machine losses caused by harmonic magnetic fields are calculated in detail and the corresponding density distribution is displayed. Finally, the torque obtained from the proposed equivalent circuit are compared with the results calculated by FEM and experiments. The comparisons clarify that the proposed method can account for the equivalent circuit in IMs with high accuracy.