PROJECT TITLE: Multi-Stator Permanent Magnet Machines For Stand-Alone Wind Power Generation
Collaborator: Zhejiang University, China.
Compared with conventional machines, permanent magnet (PM) machines are much more efficient. However, high energy product PM is very expensive. Hence, it is very important to effectively utilise PM material, i.e. high power to magnet material ratio. On the other hand, it is always a key target to improve the power density and efficiency. The motivation led to a new type of PM machines, double stator PM machines. They have two airgaps on both inner and outer sides of magnets. Both stators can act on the rotor to produce torque. Therefore, the power density can be significantly enhanced. They have great potential in such applications as wind power generator, electrical vehicle, hybrid vehicle, and robots etc. By way of example, the double stator topology can greatly boost the power rating of stand-alone wind power generators. The higher power density is preferred by the stand-alone wind power generation system. The rotational speed of direct drive wind power generator is low, which requires large number of pole pairs and a small aspect ratio, the axial length to diameter ratio. Therefore, such generators usually have a large space inside, which is not used. The double stator topology can effectively utilize this empty space. Hence, the power rating can be significantly boosted within the same envelope.
The main objective of the project is to investigate a kind of PM machines having multi-stators, such as two or three stators.
The project will involve:
- To analytically optimise machine parameters such as split ratio, pole number, slot size, magnet size and winding etc.;
- To develop the cogging torque and torque ripple minimization methods;
- To investigate the eddy current loss in magnets;
- To design and make two prototypes.
Publications in journals and conference papers may be found at VBN.