Research On Sensorless Control Of High Speed Permanent Magnet Synchronous Motor Based On Sliding Mode Observer

As the core part of high-speed motorized spindle, high-speed permanent magnet synchronous motor(PMSM) is superior at dynamic response, productivity and power density, and it is receiving public concern increasingly. The control performance of high-speed permanent magnet synchronous motor determines the work efficiency of high-speed motorized spindle, so researching on the control and drive system of high-speed PMSM has a high application value. Due to the restriction of the structure of high-speed PMSM, it is not suitable for installing a sensor on the motor. Therefore, the sensorless control of high-speed permanent magnet synchronous motor has been the scholars’ research hotspot all the time. Sliding mode observer, as an application of sliding mode variable structure control used in sensorless control, has the advantage of strong robustness and high observation accuracy. However, in the practical engineering application, its chattering problem will exert a bad influence on control efficiency. Based on traditional sliding mode observer, the object of suppressing chattering, improving sensorless control accuracy, enlarging high-speed PMSM speed adjustable range, strengthening high speed PMSM control system robustness, and the exploration of the sliding mode variable structure theory combined with linear state feedback control theory, this paper will mainly probe into the sensorless control of high-speed permanent magnet synchronous motor.Firstly, this paper builds the sliding mode observer mathematical model of high-speed permanent magnet synchronous motor according to the analysis of mathematical model of PMSM and sliding mode variable structure theory, the reason of chattering problem is also analyzed according to the digital motor control system.Secondly, a new sliding mode observer, which makes improvement in switch function, sliding mode observer coefficient and the processing of switch signal, is introduced in this paper, and its characteristics of low chattering and high observation accuracy are also analyzed and verified through MATLAB.Thirdly, the weak robustness of new sliding mode observer is analyzed through classical control theory, and load torque feedforward strategy and stator resistance adaptive sliding mode observer are proposed to improve the robustness of the system.Finally, the experimental platform of high-speed PMSM drive and control system is established, and the hardware system based on TMS320F28335 DSP and the software are designed to verify the effectiveness of these new control algorithms.