Permanent Magnet Synchronous Motor Sensorless Control Technology Research

AC permanent magnet synchronous motor with its superior performance is widely used in industrial production, aerospace, and in People’s Daily life, etc. Motor vector control need accurate rotor position and speed feedback with real-time, but due to the environmental impact, in the actual working condition of mechanical detection sensor affects the control stability and increase system complexity, at the same time increase the cost of system. To solve this problem, the ac permanent magnet synchronous motor sensorless technology has important practical significance and application prospect.After decades of development, domestic and foreign scholars research and practice a varieties of solutions about permanent magnet synchronous motor sensorless control. Estimate algorithm based on motor model can be used for ac permanent magnet synchronous motor in high speed running, but it can’t detect the rotor initial position, and detection precision is low at low speed; High frequency signal injection method can accurately extract the rotor position and speed information, but in the high speed running, the back electromotive force will affect the detection. So, this paper proposes launches the initial position of motor sensorless detection and sensorless run at full speed.This paper based on the SVPWM technology to realize the initial position detection, and the experimental results show that the method can accurately obtain the rotor initial position. And then, research sliding model structure, and base on sliding model observer build the simulation model of sensorless motor, and carry out the simulation experiment; And on DSP2812control hardware platform to open loop start motor, accord with certain conditions and then switch to the sliding model observer for sensorless motor running, from the simulation and experiment results show the method can apply to high speed running. Finally, according to the principle of high frequency injection method to build motor sensorless simulation model, and carries on the low speed simulation, The simulation experiment proved that this method can be used for motor sensorless control at low speed from the simulation results.