Design And Optimization Of Semi-direct Drive Switched Reluctance Motor For Beam Pumping Unit

Most beam pumping units still adopt the two-stage transmission mode of induction motor and pulley driving reducer,which makes the system inefficient.At the same time,the induction motor works under light load for a long time,which leads to low motor efficiency and power factor,resulting in huge waste of energy.Although the existing transmission scheme of low-speed permanent magnet motor replacing induction motor and pulley improves the system efficiency,the permanent magnet motor not only consumes rare earth materials,but also has higher cost.In order to solve the shortcomings of the above two transmission modes,this thesis proposes that the low-speed switched reluctance motor can replace the permanent magnet motor for the pumping unit,and mainly studies the following aspects for the switched reluctance motor:Firstly,a 16.5k W switched reluctance motor with low speed and high torque is designed for CYJY5-2.5-18 HB beam pumping unit.The effects of different stator/rotor pole numbers,motor split ratio and air gap length on motor performance are compared.The motor is modeled and simulated by ANSYS Maxwell software,and the correctness of the designed motor is verified.Secondly,the method of weaken the peak current of switched reluctance motor is studied.The first is to study the feasibility of applying oriented silicon steel materials to the stator to improve the saturation resistance of stator poles.The other is to study the feasibility of changing the structure of stator poles,broadening the magnetic circuit at saturation position and improving the anti-saturation ability of stator teeth.Finally,the feasibility of weakening the peak current by current chopping control is studied.The feasibility and effectiveness of the proposed scheme are simulated and analyzed by finite element software.Then,the design methods of two stator teeth structures which are convenient for fixing slot wedges and their influences on motor performance are studied.For switched reluctance motor stator teeth with pole shoes,the matching law between pole shoes width and stator teeth width is studied.For Switched Reluctance Motor stator teeth with grooves,the influence of groove size on motor performance is optimized.Finally,the internal temperature distribution characteristics of the designed motor are simulated and analyzed.Simplify the 3-D model of motor by Solid Works software;Solve the heat source parameters of the motor,carry out equivalent calculation on the motor winding,and determine the heat dissipation coefficient of the motor surface;The ANSYS Fluent module is used to simulate and analyze the internal temperature rise of the motor during rated operation,and verify the thermal rationality of the motor.