Theoretical Analysis for Rapid Design of Hybrid Excitation Synchronous Machine With Consequent Pole Rotor

Due to the three-dimensional (3D) flux distribution, the 3D finite element method (FEM) is often used to design the hybrid excitation synchronous machine (HESM) with consequent pole rotor, but it can be time-consuming. This paper proposes a rapid design method for this type of machine. Firstly, the relationship between the structure and magnetic field distribution of the homopolar inductor machine (HIM), consequent pole permanent magnet machine (CPPM), and HESM is clarified. It is pointed out that the magnetic field generated by the field winding (FW) of HESM can be regarded as that of HIM, and the magnetic field generated by the permanent magnet (PM) can be regarded as that of the CPPM. Secondly, based on the mathematical models of HIM and CPPM, the analytical expressions of HESM including airgap flux density, back electromagnetic force, and inductance are derived. Thirdly, the equivalent models of HIM and CPPM are developed respectively. Theoretical analysis shows that HIM can be viewed as a wound rotor synchronous motor (WRSM) and CPPM can be viewed as a permanent magnet synchronous motor (PMSM). Then, the performance of HESM with consequent pole rotor can be predicted by that of WRSM and PMSM. Finally, the rationality of the design method is verified by simulation and experiment. Results show that it has reduced the calculation time significantly on the premise of high accuracy, which will be helpful for the design and analysis of HESM.