Research On Sensorless Control Strategy For High-speed Permanent Magnet Synchronous Motor In Full-speed Range

With the rising demand for the output power and speed control performance of motors in various industries and the rapid development of permanent magnet materials,HSPMSM has been widely used in electric vehicle drive systems,ship electric propulsion systems and aerospace power systems.In recent years,MPC is an emerging motor control technology,compared with the traditional SVPWM,it has the advantages of simple structure,easy implementation,can be extended and handle the system’s Non-linear constraints,gradually become the current research hot spot.In existing synchronous motor drive technologies,both the traditional SVPWM and the emerging MPC,real-time motor speed and rotor position angle information must be obtained,and position sensors are usually used to obtain motor position information.However,the cost,installation and maintenance of position sensors limit their use in high speed motor drives,so a position sensor-less scheme that uses estimated position information for control is a more suitable option.In order to achieve position sensor-free operation over the full speed range of the HSPMSM,this paper accomplishes the following work based on MPC technology.1.In this paper,the mathematical model of a permanent magnet synchronous motor is introduced.Based on this,two model predictive control methods for motor drive systems are introduced,one is model predictive current control and the other is model predictive torque control,and their correctness and effectiveness are verified by building Simulink simulations and experiments.2.In order to realize the full-speed range sensorless operation of the HSPMSM model predictive control system,a SMO is constructed in this paper,which estimates the extended counter-electromotive force of the motor and then uses a PLL to estimate the position information.A reference speed generator is also designed to enable motor start-up and lowspeed operation,and an algorithmic switching strategy for full-speed domain operation is proposed.And on this basis,model predictive current control is adopted as the modulation of the voltage vector,the feasibility and reliability of the proposed scheme is verified by simulations and experiments.3.Considering the problem of parameter variation during high-speed operation of the HSPMSM,a model-free predictive control method without using any motor parameters is investigated in this paper to replace the predictive control based on the exact model of the motor,in view of the parameter dependence problem of the MPC.At the same time,an improved SMO algorithm is designed to address the shortcomings of the conventional SMO position estimation scheme,combining model-free predictive control with improved SMO so as to reduce the impact of parameter variation on the control performance without position sensors,and the advanced and superiority of the proposed method is verified through simulations and experiments.