| The linear motor is a sort of transmission system that transfers electric energy to linear motion directly and it has been applied in the fields of industry and military affairs for its favorable features of simple structure, no centrifugal force, etc. Especially the transverse flux permanent magnet linear machines (TFPMLM for short) have shown a brilliant prospect in low speed, high torque systems with special configuration and large thrust force. As the TFPMLM isn't mature and there are still a lot of aspects to study, it's necessary to develop a further research on it.The research work is firstly focused on some basic problems. The mechanism of the cogging force is analyzed and its period is also studied. The principle of force magnification is then given. By introducing a so-called equivalent PM current a model is proposed for predicting TFPMLM'steady state performance including the saturation effect.The magnetic field is generally analyzed with three dimensional finite element method and the view is put forward that the 3D magnetic field in the TFPMLM can be achieved by modifying the axial field and the radial field. The characteristics of the cogging force, no-load flux linkage and force vs. displacement are also worked out based on it.Aimed at the problem of a large d-axis current, the method of commutation advance angle control is studied. It proves that this method can decrease the hysteretic current effectively and hence improve efficiency. A circuit wholly with hardware is designed and the open loop control has been put into practice.The elementary experiments have been carried out. The results accord with that of simulation, which verifies the validity of finite element analysis in the prediction of the performance of the TFPMLM.
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