The study of bypass hybrid excitation synchronous motors with extended field-weakening capability

In this paper the structure and operation principles of a kind of bypass hybrid excitation synchronous motor (BHESM) are presented. Based on the conventional permanent magnet machines, two field windings are added on the machinepsilas two ends. The permanent magnet (PM) provides constant flux, and the field windings produce the variable flux. The special flux excitation pattern will make BHESM a challenging candidate for wide speed range application. The operation principle of the BHESM is introduced, and the equivalent magnet circuit and FEA model are built to analysis the machinepsilas magnetic field and predict the performance. Some optimization advises are also proposed.