Research Of Sensorless Vector Control For PMSM Based On Sliding Mode Observer

Owing to the control theory applied in the field of motor control and it has the advantages of light-weight, small-size, simple structure and high power density, PMSM has played a more and more important role in the daily life, industrial and agricultural production and national economic development. Sensorless vector control of PMSM is one of the hot research topics.First of all, the basic principles of PMSM vector control and several commonly strategy of the vector control were discussed in this thesis. Given in this paper, using the surface mounted PMSM, comparing the merits of different control strategies to choose the vector control strategy of Id=0. It also introduces and analyze the commonly used SVPWM modulation technology, and presents its simulation model under Matlab/simulink.Secondly, this paper introduces the basic principle of sliding mode variable structure and analyze the reason which cause the unique "chattering". On the basis of the mathematical model of PMSM, a sliding mode controller was designed to observe the rotor position or speed and put forward an improved sliding mode controller aimed at the parametric variation in the actual operation. Through the study of the online identification of stator resistance and feedback to the mathematical model of PMSM to improve the observation precision of the sliding mode observer. The Matlab simulation results also verify the previous theoretical analysis.Thirdly, the hardware and software of PMSM control system was desired according to sliding mode observation. This paper has built the hardware platform base on the TI DSP TMSF28023which include the control circuit, main circuit, auxiliary power supply circuit and sampling circuit. In the aspect of software part it is introduced in detail which includes the whole control system software design principle, the system flow charts of main program and its related subroutines and the starting part of the program. In order to process the data from the lower machine conveniently, a slave computer program is programmed based on serial communication interface (SCI) to realize the data communication between upper machine and lower machine.Finally, we do an experiment on the hardware platform, and analyses the experimental data and the experimental waveforms, verify the correctness and feasibility of the algorithm.