Preliminary experimental verification of self-excited wound-field synchronous motor with auxiliary poles for automotive applications

This paper describes a rare-earth-free synchronous motor where space harmonic power is utilized for field magnetization instead of permanent magnets for automotive applications. The stator has a concentrated winding structure, and the rotor has separate two types of windings, i.e, an induction coil that retrieves mainly the second space harmonic and an excitation coil for the field magnetization. The two coils are connected via a center-tapped full bridge diode rectifying circuit. The theoretical analysis is conducted, and the mechanical configuration is discussed. In addition, preliminary experimental test result is demonstrated from the viewpoint of the principle of self-excitation.