Permanent Magnet Synchronous Motor Servo System Based On Linear Hall Sensors

Permanent magnet synchronous motors (PMSM) have many advantages such as high power density, high output torque and simple operation etc. Therefor, they have been wildly used in many fields like aerospace, national defense, home appliances and so on. With the emergence of new structure motor and novel control strategy, miniaturization, integration and lightweight of the motor and its driver have become the mainstream trend. In this thesis, the following ground topics around several key technologies of the PMSM sevor system have been done:A rotor position sensor based on linear Hall ICs is designed for a PMSM. Sinusoidal air-gap magnetic flux density is obtained by optimizing the permanent magnet ring. The errors of the position sensor are discussed in details, while the corresponding hardware compensation measures are also provided. The accuracy of the position sensor has been tested in different temperature.The distribution regularities of the rotor position sensor's errors are detailedly judged by using different criteria, based on which the Kalman filter and Extended Kalman filter are built for the rotor postion signal decoded by DSP and the outputs of the position sensor to elimate noises. Through a comparison of the two filters'performances, the Kalman filter is finally chosen to improve the rotor position angle decoding precision.The internal model controller is designed for the current loop to achieve quadrature and direct-axis voltage decoupling control, and the PI regulator is designed for the speed loop. High accuracy vector control is employed by using the rotor position signals detected by DSP.According to the drawback that the internal model controller of the current loop is sensitive to model parameters, the model reference adaptive systems (MRAS) of the stator resistance and inductance are designed based on Popov hyperstability, the value of resistance and inductance can be identified correctly, thus the current internal model adaptive control can be achieved to improve the PMSM servo system's robustness and control accuracy.