Design And Operation Performance Analysis Of Low-speed Submersible Permanent Magnet Motor With Different Tooth Width

The low speed direct drive submersible permanent magnet motor has a lower torque density and a more elongated structure than the high speed induction motor supplemented by planetary gear reducer.The slender motor increases the difficulty of wire embedding,and the conductors in the slot are difficult to arrange neatly,resulting in a low slot full rate and even the phenomenon of conductor entanglement,which may cause conductor insulation damage and wire embedding failure;On the other hand,the motor is too long,which also brings difficulties in downhole operation of submersible progressing cavity pump.Improving the torque density of the motor through the design of the magnetic circuit structure of the motor is an effective method to reduce the length of the motor.In order to obtain the high torque density of the low-speed submersible permanent magnet motor,the main contents of this thesis are as follows:Firstly,the electromagnetic design of traditional fractional slot low speed submersible permanent magnet motor has been studied.The influence of different pole groove matching on the performance of permanent magnet motor has been analyzed.The influence of slot parameters of stator slot on motor torque has been studied and the optimal parameters of motor performance have been determined.The no-load performance and load performance of the motor have been analyzed by electromagnetic finite element commercial software simulation.Then,the influence of stator structure with unequal tooth width on torque performance of low speed submersible permanent magnet motor has been studied.The width ratio of big tooth and small tooth has been adjusted,the torque performance has been simulated by electromagnetic finite element software,and the best width ratio of big tooth and small tooth have been selected.Comprehensively calculate and analyze the no-load performance and load performance of large and small tooth motor;The method of reducing the torque of unequal tooth width slot and electromagnetic torque fluctuation by changing the rotor structure has been studied to reduce the wear of vibration and prolong the life of the motor.Finally,the influence of eccentricity on performance of permanent magnet motor with unequal tooth width has been studied.The low speed submersible permanent magnet motor with sliding bearing has both static eccentricity and dynamic eccentricity.The influence of static eccentricity on electromagnetic torque and cogging torque of permanent magnet motor has been studied.The influence of dynamic eccentricity on electromagnetic torque and cogging torque of permanent magnet motor has been studied.