Design And Control Of A Novel 12/8 Segmental Rotor Type SRM

Different from conventional structures, the stator irons, or several rotor irons are constructed from a series of discrete segments which are embedded in aluminum(conductive metal) rotor block. This kind of structure makes the SRM have many advantages, such as less maintenance, higher fault tolerance, rugged construction, except for the advantages at high-temperature and high-speed in the conventional SRM. This kind of SRM is called segmental SRM. According to advantages above, the segmental SRM can be well used in applicable systems such as household systems and aerospace system.In the thesis, a novel 12/8 segmental rotor type switched reluctance motor(SRM) is proposed for cooling fan applications. Unlike conventional structures, the rotor of the proposed structure is constructed from a series of discrete segments, and the stator is constructed from two types of stator poles: exciting and auxiliary poles. Moreover, in this structure, short flux paths are taken and no flux reversion exists in the stator. While the auxiliary poles are not wound by the windings, which only provide the flux return path. When compared with the conventional SRM, the proposed structure increases the electrical utilization of the machine and decreases the core losses, which may lead to a higher efficiency.To verify the proposed structure, a prototype of the novel structure is designed to compare with a conventional 12/8 SRM, which is designed for cooling fan application(12V, 500 W, and 2800r/min). The SRMs are designed for the same application so that the external stator dimensions and shaft diameters are the same. The stack lengths are also equal so that the both machines roughly have the same volume. The finite element method(FEM) and Matlab-Simulink are employed to get the static and dynamic characteristics of the both SRMs. Finally, a prototype of the proposed motor is tested for characteristic comparisons. Further, in the experiment, the torque and the efficiency of the proposed motor are higher than that of the conventional 12/8 SRM.