Sensorless Control Of Printed Permanent Magnet Synchronous Motor

Permanent magnet synchronous motors(PMSM)are widely used nowadays,from household appliances,electric vehicles,to aerospace,and have permeated every aspect of people’s lives.The design and application of new motors with high performance,high energy density,and low operating costs have always been the goal pursued by people.Printed permanent magnet synchronous motor is a type of disk type coreless permanent magnet motor.The stator is manufactured using sophisticated PCB technology,which makes the motor stator have a large contact area with air,good heat dissipation performance,and high energy density.At the same time,the high manufacturing accuracy of PCB makes the printed motor have good operating performance.Due to the absence of an iron core in the stator,the motor also has low iron loss and low stator inductance,which is characteristic of high-speed motors.As a disc motor with a very short wheelbase,it can be used in electric vehicle hubs,robot joints,and other occasions.Therefore,it is of great significance for the research and application of printed permanent magnet synchronous motor control and position sensorless control.In this thesis,the mathematical modeling and theoretical analysis of printed permanent magnet motor are carried out,and the motor parameters are determined through calculation and measurement,laying a foundation for motor control.The vector control system of printed permanent magnet synchronous motor is established,and the PI parameter tuning strategy is given.The external rotation speed auto-disturbance rejection control strategy is adopted to optimize the operating performance of the motor.In order to solve the problem of motor stator current chattering caused by minimal stator inductance,series inductance is used to filter out high-frequency stator current chattering,optimize the electromagnetic torque output of the motor,and improve the load carrying capacity of the motor.The state space equation of the series inductance motor system is given,and the effectiveness of the scheme is verified through simulation and experiments.By establishing a first order sliding mode observer to estimate the rotor of a printed permanent magnet synchronous motor,the simulation found that the high-frequency chattering of the motor stator current can exacerbate the high-frequency chattering of the sliding mode observer’s back electromotive force output,further affecting the rotational speed and rotor position chattering,and ultimately exacerbating the electromagnetic torque chattering.In the sensorless control algorithm,a hyperbolic tangent function with variable slope is used to replace the symbolic function to weaken the output chattering of the sliding mode observer,and an adaptive control rate gain is designed to improve the stability of the sensorless operation of the motor.Finally,a second-order super-twisting sliding mode is used to weaken the high-frequency chattering of the motor under load,and the idea of a first-order sliding mode adaptive control rate gain is adopted to further enhance the stability of the sliding mode observer.In order to further improve the sensorless performance of printed permanent magnet synchronous motors,a single vector operation cycle analysis of the stator current of the printed permanent magnet synchronous motor was conducted,and a conclusion was reached that the motor control switching frequency can be matched according to the motor parameters.A modified differential equation for the sliding mode observer of a series induction motor system is presented.Comparing two strategies for improving printed permanent magnet synchronous motor performance,namely,series inductance and high switching frequency,using high switching frequency to reduce motor stator current chattering,optimize torque output,and improve sliding mode observer estimation accuracy,the correctness of the theory was verified by building a simulink simulation.Finally,a driver for printed permanent magnet synchronous motor(PMSM)is designed,and a high-performance operation without position sensors at a high switching frequency of 150 k Hz is achieved,verifying the correctness of the theory and simulation in this thesis.The thesis has 76 figures,12 tables,and 70 references.