Research On Sensorless Vector Control Of PMSM

With the development of permanent magnetic materials and constantly improve of the control strategy of motor, PMSM is more and more widely used. To match with different work environment, higher reliability and superior performance are required.For the incremental photoelectric encoder is lack of the ablility to detect the initial position of PMSM, a method based on low frequency rotating voltage signal injection is proposed in this paper. The initial position of PMSM can be obtained by using the encoder detect the tiny rotation of rotor under the voltage signal injection, and it is verified on the dSPACE experiment platform.The method of sensorless control of PMSM has been a hot research topic, as it can replace the role of the sensor, decrease the volume of the machine and reduce the cost. In this paper, the principle of high frequency signal injection method and Luenberger observer are analyzed in detail, and some optimization have been applied in the concrete implementation process of the two methods. The method based on the Luenberger observer is verified on the Simulation software, and the experimental systems of the two methods are builded on the dSPACE experiment platform respectively. On this basis, the sensorless control of PMSM in low speed is realized by using the high frequency signal injection method. Likely, the sensorless control of PMSM in middle-high speed is realized by using the Luenberger observer.Finally, by using the weighted method, the combination of the two sensorless control methods is proposed in this paper. A new controller is designed based on the dSPACE experiment platform, and the experimental results indicate that the sensorless control of PMSM from static to high speed can be realized by using the composite method.