Sensorless Control Of PMSM Based On High Frequecy Voltage Signal Injection Method

With the aggravation of the energy crisis and high oil prices,the proportion of hybrid and electric vehicles gradually increases.The motor drive system,as the core of the electric vehicle,is directly related to the system performance and efficiency,which affects the development of the electric vehicles.The permanent magnet synchronous motor(PMSM)has many merits such as sample structure,high power density,wide speed range and high efficiency,which has become the mainstream of the motor and very suitable for the electric vehicle system.In the practical motor drive system,the information of the rotor position and speed is essential to achieve good control performance.However,the speed sensor not only increases the cost and volume of the system,but also reduces the reliability of the system.Thus,the sensorless control of the PMSM system has much significance for its industrial application.In this paper,on the basis of PMSM physical characteristics and the detected currents and voltages,the sensorless control strategies based on high frequency voltage signal injection(HVSI)are studied.The main contents are described as follows.1.Mathematical models of PMSM in different coordinates are built,then detailed analysis of space vector modulation of voltage source inverter and vector control of PMSM system is given,the simulation results have verified the correctness and effectiveness of the strategy based on Matlab platform.2.On the basis of the magnetic characteristics,high frequency mathematical models of PMSM are established.Three sensorless control methods in different coordinates are discussed to estimate the rotor speed,and the corresponding rotor estimators are discussed.The simulation results have verified the correctness and effectiveness of the strategy based on Matlab /Simulink platform.3.The experimental platform is constructed based on the control core of DSP+FPGA and the voltage source type inverter,and then the corresponding software system is given.The experimental results verify the correctness and validity of the above methods.