Research On Vector Control Of Permanent Magnet Synchronous Motor With Low-precision Position Sensor

In the high precision servo control of permanent magnet synchronous motor(PMSM),vector control is the mainstream speed control technology.But,the vector control technology needs the real-time and accurate position information of the motor rotor,so the position detection technology is vital.However,in sensor technology,the higher the precision,the more expensive the price is;and sensorless technology is not yet mature.Therefore,PMSM has not been well applied in some cases where require high reliability but low cost.Through the algorithms,this paper improves the resolution of the low-accuracy Hall position sensor,so as to realize the vector control of PMSM and broaden its application range.Firstly,according to the output characteristic and installation method of the latch Hall position sensor,the paper analyses "self error" and "installation deviation" of hall sensor in the practical application process.The measured results show that the above deviations do exist.Secondly,this paper uses the angle subdivision strategy to improve the the resolution of the position signal,using the average velocity method and the acceleration method to accumulate the electric angle.The simulation model is built in the Matlab/Simulink,and the validity of the angle subdivision strategy is verified.Considering the problem of deviation in practical application,the strategy needs to take corrective measures.Then,the whole-dimensional State observer method is proposed,which no need to consider the "self error" and "installation deviation" of Hall sensor.At the same time,in view of the large fluctuation of the observer correction will affect the observation,the dual observer strategy is proposed,and the simulation model is built in the Matlab/Simulink to verify the effectiveness of the dual observer strategy.Finally,the paper designs the software and hardware platform of the motor controller,and completes the dual observer strategy verification and contrast experiment on the platform.The experimental results show that the vector control of permanent magnet synchronous motor can be achieved by using the double observer strategy and has better control performance.