Research On Safe And Stable Operation Of Permanent Magnet Synchronous Motor For New Energy Vehicles

New energy vehicles will be the trend in policies advocated by the state,for carbon neutral and people’s daily needs.In new energy vehicle’s electrical control system,PMSM will become mainstream in auto enterprise by high power density,high efficiency and high reliability.Speed sensors collect information from Motor rotor position and speed is the motor controlled drive mode,but the disadvantage of mechanical sensor is high cost and harsh use conditions.So,Research on low cost and high reliability permanent magnet synchronous motor with sensorless control method have great significance.This paper takes PMSM for new energy vehicles as the research object,Use permanent magnet synchronous motor with sensorless control method instead of mechanical sensor.The main research content of this paper is as follows:1.Analyze the mechanism characteristics of PMSM,Establish PMSM mathematical model in each coordinate system,exposit the basic principle and implementation method of SVPWM,laying the foundations for PMSM without speed sensor through analysis and simulation of vector control algorithm.2.For normal PMSM drive mode use mechanical sensor to collect Motor rotor position and speed information,but the disadvantage of mechanical sensor is high cost and harsh use conditions.This topic adopts speed sensorless control strategy of high frequency signal injection to replace the use of mechanical sensors,for the cost of installation and maintenance of mechanical sensors and high reliability control can be saved.3.For the traditional high-frequency injection method,the feedback current needs to be processed to obtain the position error Angle information,the rotor position Angle is estimated by the rotor position observer,this way of calculation is more cumbersome.Based on this,this paper proposes an improved double closed-loop I/F control method to realize the real-time double closed-loop system of current amplitude and angular velocity,so as to improve the current utilization rate and the anti-load capacity of the motor.4.For traditional high frequency pulse signal injection method of vibration motor resistance and the inductance parameter mismatch lead to system instability,and mostly ignored counter electromotive force in the process of theoretical derivation and cross coupling problem of the impact of estimation error,this paper puts forward to join phase-locked loop technology and comply with a new modulation signal in response to the current processing,Finally,the control system is not affected by the motor parameters and the position error compensation is added to avoid the interference term.5.Built the motor experiment platform with TMS32OF28335 as the main control chip.And code for high frequency pulse injection.Base in no-load and loaded conditions of the vehicle as the research content,the verification experiment was carried out on the experimental platform of the permanent magnet synchronous motor control system to further verify the reliability and safety of the control method.