Main Parameter Computation And Analysis Of Disc Type Permanent Magnet Motor

Permanent magnet motor is a new style motor which take permanent magnet for excitation. However the shape and position of permanent magnet is various, and the magnetic structure is complicated, the computation and analysis of permanent magnet motor is more complicated than normal motor. The structure of disc type permanent magnet synchronous motor (PMSM) is different from traditional motor; its magnetic field problem is more complex. Therefore, it is necessary to research and investigate the effective method to analyze electromagnetic field of disc type permanent magnet motor, and it is significant and practical to improve the designing level of disc type permanent magnet motor.The magnetic field distribution of disc type motor is axial, the computation of disc motor has to use 3D model. However 3D computation requires higher disposition of computer, it cannot be satisfied under normal conditions. In this paper, the 3D model of disc motor is simplified, and it can be equivalent into 2D steady and transient field to compute electromagnetic field. The simplified model can be testified right through experiment. Meanwhile, the thesis proposes the existing of zigzag leakage in multiple poles few slots PMSM, and summarizes the computation method of leakage factor. The leakage factor calculated by this method is identical to experiment value, whatever the structure of motor is radial or axial. On the basis of equivalent 2D model of disc type motor, the method to compute armature reaction reactance of radial PMSM has brought into computing steady state reactance of disc type motor, and it is tested to be practicable by experiment.When permanent motor work on the state of starting, locked rotor and suddenly stalling etc., armature reaction of winding current will exert strong demagnetized action, and it will descend the work-point of permanent magnet outstandingly. The software Ansoft has been used to simulate 3-phase suddenly short-circuit process. A transient method has been submitted to check maximal demagnetize work point of permanent magnet, and it has been used to check two structure shape, radial and disc type, permanent magnet motor. Through experiment of radial permanent magnet motors, the method has been proved feasible, and it will supply a reliable base for permanent magnet motor designing.