Study On Permanent Magnet Synchronous Motor Control Technology Based On Single Resistor Current Reconstruction

Permanent magnet synchronous motor(PMSM)has the advantages of large starting torque,smooth and stable operation,avoiding the disadvantages of high power loss and serious heating in the excitation winding of electric excitation motor.It is widely used in industrial drive and high-precision servo tracking.According to statistics,the total capacity of PMSM accounts for70% just in the new energy vehicle industry.At present,the speed control of PMSM is usually realized by vector control.In this control mode,the real-time information of motor phase current and rotor angle must be obtained through the mechanical sensors installed in the motor control system,which increases the cost of the motor control system to a certain extent.In order to reduce the cost of motor control system,this paper mainly studies the low-cost control technology of permanent magnet synchronous motor through the new phase current sampling method.Firstly,the mathematical model of PMSM is deduced in detail,and the space vector pulse width modulation(SVPWM)is introduced,which will lay nice foundation for the follow-up research.Secondly,on the basis of space vector pulse width modulation technology,the phase current reconstruction technology based on bus shunt resistance is deeply studied,and the corresponding relationship between bus current and motor phase current is deduced.The current reconstruction model is built in MATLAB/SIMULINK,which achieves the basic phase current reconstruction.Aiming at tackling the problem of sampling non-observation area in the current reconstruction scheme,this paper uses the phase compensation method to make up the defect,and the feasibility of the compensation scheme was verified by simulation results and experiments.In order to reduce the complexity of current reconstruction algorithm,this paper proposes another current reconstruction scheme based on low-pass filter and coordinate inverse transformation,which realizes the motor phase current reconstruction well.Finally,in order to further reduce the cost of the control system,this paper studies the sensorless control technology of PMSM.This paper focuses on the realization method of no position control technology based on model reference adaptive system(MRAS).According to the simulation results,the dynamic response effects of no-load,load,speed mutation and load mutation are verified and analyzed.Furthermore,the bus shunt resistance sampling technology is combined with the sensorless control algorithm based on MRAS,and the feasibility of the control scheme is verified by simulation.