Electromechanical Characteristics Analysis And Structure Optimization Of Switched Flux Motors For Servo Presses

For The servo direct drive press.the drive structure is simple and does not have the characteristics of mechanical flywheel smooth energy consumption,the performance and coutrol of direct drive motor becomes the of servo direct drive press,so the research and improvement of metor performance plays a vital rale in the high quality operation of servo press.Aiming at the characteristics of servo press working conditions;this paper studies the key technical issues of switching flux switching permanent magnet motor as servo press motor,which has a simple structure,high rotor impact high efficiency,high power density,permanent magnetic chain and counter-electromotive force waveform similar to sinusodal waveform,and superior torque performance comprared with traditional permanent magnet motor.However,due to the biconvex structure of the switched flux switching permanent magnet(FSPM)motor and the high air-gap magnetic density generated by the permanent magnet field,it has a large cogging torque,which in turn generates large torque fluctunation,and these problems still need to be optimized by further research.According to the requirements of the FSPM motor for servo direct-drive,the structural model and the electical,magnetic and mechanical models of the FSPM motor for servo direct-drive press are established by combining the working principle,mathematical model,rotor/stator tooth coordination law,winding method and winding turns of the biconvex permanent-magnet motor,and the characteristics of the physical variables such as magnetic chain,induced eletric potential and inductance in the time domain and The magnetic model is used to analyze the distribution of magnetic density clouds under no-load conditions,and the cogging torque and torque fluctuations under the force model are analyzed.fluctuations are large.By analyzing the influence of air gap width,permanent magnet thickness,rotor tooth width and other factors on the output torque and fluctuation of the motor,the influence law of each structural parameter on the output torque and torque fluctuation of the motor is determined,and the coupling three factors affecting the magnetic circuit are analyzed based on the energy method,which are stator tooth width,rotor tooth width and permanent magnet width,and the Box-Behnken method is used to design the simulation experimental samples,and the average torque,torque fluctuation to torque ratio and the ratio of the average torque to the model area of the permanent magnet are defined as the response indexes.The response indexes of different experimental samples are obtained by finite element simulation.And the response index model is fitted by quadratic polynomial,after which the optimal solutions of maximum average torque,minimum torque fluctuation to average torque ratio,and maximum average torque to permanent magnet model area ratio are found by the trust domain method.The obtained optimal solutions are brought into the finite element model for verification.The results show that compared with the initial motor structure parameters,the optimized motor has 43.75%higher average torque,81.10%lower torque fluctuation,and 26.7%less permanent magnet usage.A motor control model based on the FOC control principle is established to verify the performance of the optimized motor,and the FSPM motor is obtained by simulation to operate well in steady state with fast dynamic response.The electrical,magnetic and mechanical properties from the FOC control simulation and finite element simulation are compared with the experimental results of the prototype,and the results show that the simulation and experimental results have good consistency,but there are also certain data errors,and the analysis of the error causes mainly from the motor manufacturing and assembly errors,ignoring the errors caused by end leakage magnetism,and the modulating waveform does not fully match the three-phase sinusoidal waveform caused by the motor control.These errors have some influence on the performance of the motor to a certain extent.In general,the FSPM motor studied in this paper can meet the needs of practical engineering in terms of torque and efficiency,and the experimental study also proves the reasonableness of the motor design and the accuracy of the simulation calculation.