Low-speed Detection And Control Of AC Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor (PMSM) has advantages such as compact shape, light weight, low inertia, high efficiency and high performance, and as the development of power electronics, microprocessor technology and motor manufacture technology level, the AC servo system based on PMSM have been more and more widely used in fields as national defense and industry. This paper makes a deep research on the PMSM servo system and comes up with some improvement on the low speed performance.Firstly, this paper introduces the background and importance together with the AC servo system developing situation and tendency. The mathematical model of PMSM and key points of vector control strategy based on id=0are presented after the analysis of the coordinate transformation theory, and then makes a introduction on the initial position of the motor rotor. Building the PMSM closed loop vector control system under MATLAB/SIMULINK to explain the validity of id=0control strategy.On the analysis of influencing factors of the motor low speed performance, we compare the usual measuring methods in position and speed process and it proves that the M/T method could get a higher measuring precision and a wider measuring range, and then we show its specific realization. Moreover, this paper also introduces some other methods for improving Low-speed performance. Auto-disturbance-rejection control (ADRC) strategy makes the system have no super tonality and good robustness, and thus enhance the quality of control system which can improve low-speed performance.In the hardware design chapter, it introduces the overall scheme of hardware design first and then shows the structure block diagram. The control system takes the DSP TMS320F2812as the main controlling chip while the power circuit takes the IPM PS21267as the key component. Then it shows the working principle, component selection, specific realization and parameter calculation of the main circuit, control circuit, auxiliary power supply (APS) and interface circuit in detail.In the software design chapter, it introduces the variable used in the program and present the design alternate of the system software. Then in introduces some initialization program including rotor position initial position detection program. At last, it talks about the kernel program design method including SVPWM arithmetic incorporated with kernel control program flow chart.Finally, it makes a work summary for the whole paper and puts forward some further improvement proposal.