Research On Sensorless Control Of PMSM Based On High Frequency Signal Injection Method

Permanent magnet synchronous motor(PMSM)has the characteristics of simple structure,reliable operation and high-power density.It is an ideal choice for high-performance industrial transmission.Most PMSM drive systems in the market are based on mechanical sensors to measure motor speed and position.The use of this sensor will increase the complexity and volume of the system,significantly increase the cost and reduce the reliability of the controlled drive system.Therefore,sensorless control of motor drive system has been studied more and more.Firstly,the research status of sensorless control technology of PMSM is introduced.The existing sensorless control algorithms are consulted and summarized.Secondly,the mathematical model of PMSM and the SVPWM technology are analyzed.On this basis,the theoretical analysis and derivation of high-frequency signal injection method are carried out.The position estimation observer is designed and an improved pole judgment method is proposed.Then,the influence of injection signal and PI parameters on the position-estimation effect of sensorless sensor is analyzed.The control system simulation model of PMSM is built.The pulse high frequency voltage injection method and square wave current injection method are simulated,analyzed and validated successively.Finally,a hardware platform for sensorless control based on DSP28335 with a PMSM is designed and constructed,and an experimental study was carried out.The experimental results show that the motor rotor position at zero-low speed can be estimated accurately,which verifies the feasibility and high-accuracy of the algorithm designed.