Research On Flameproof Low Speed Permanent Magnet Direct-drive Three-phase Synchronous Motor

In modern coal production,belt conveyor is the main means of transportation of coal,its transmission capacity to a large extent determines the production capacity of coal enterprises.Driving equipment for coal mine requires high reliability,maintenance-free and strong carrying capacity,and flameproof low-speed permanent magnet direct-drive three-phase synchronous motor has been widely used because it meets this application requirement and can save the deceleration links such as reducer,which has the function of energy saving and emission reduction.Taking a flameproof low-speed permanent magnet direct-drive three-phase synchronous motor with rated power of 160kW,rated speed of 60r/min and rated torque of 25466N·m as an example,the structure of rotor magnetic circuit,optimization of pole-slot coordination and reduction of cogging torque of permanent magnet direct-drive motor is synthetically considered,and combined with the previous experience of permanent magnet motor design engineering,the electromagnetic scheme is preliminarily designed.The performance and cost performance of motors with different parameters and different magnetic circuit structures are compared and analyzed.Considering the technicality and the manufacturing cost of the motor,the basic parameters of the motor are finally determined.According to the determination of structural parameters,two-dimensional finite element model is established.The magnetic field under no-load and load conditions and the amplitude of no-load back EMF and the harmonic content of radial air gap magnetic density are analyzed.The method of reducing the cogging torque of permanent magnet motor is studied and the cogging torque value of the prototype is obtained.The flux density distribution of permanent magnet motor under rated load and double rated load is analyzed.The anti-demagnetization ability of permanent magnet is analyzed to ensure the reliability of permanent magnet motor under maximum load.The parameters of iron and copper consumption of permanent magnet motor are obtained by simulation.A heat circuit model was established to check the stator winding temperature,shell surface temperature and rotor magnet temperature of flameproof low-speed permanent magnet direct-drive three-phase synchronous motor,so as to prevent demagnetization caused by excessive temperature.Finally,according to the requirements of explosion-proof joint of explosion-proof motor,the stress and natural frequency of each explosion-proof joint of motor are reasonably designed and analyzed to ensure the explosion-proof performance of motor.The motor type test is carried out according to the relevant standards of permanent magnet motor experiment,and the performanee parameters of the prototype are obtained by loading the magnetic powder brake to confirm that the performance parameters of the motor meet the requirements.Performance indicators,verify the feasibility of motor design and mechanical processing technology.