Research On Control Technology Of Sensorless Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor(PMSM)has been widely applied in industrial robots,precision machine tools,electric vehicles and other fields,because it has the advantages of high power density,high work efficiency and good dynamic response.With the increasement of PMSM application fields,the performance of PMSM is required higher and higher.As we know,the signal detection of the position and speed of the motor rotor is crucial for realizing the high-precision vector control of PMSM.Mechanical sensors are generally installed to detect the position and speed of the rotor.However,it not only increases the volume and manufacturing cost of the motor,but also reduces the reliability of the system to a certain extent.To solve this technical problem,the control technology of PMSM without position sensors is proposed.Therefore,this paper mainly carries out research on the related technologies in the PMSM system which has no position sensors,and the principal researches are illustrated as follows:Firstly,a novel adaptive sliding mode observer was proposed based on an adaptive algorithm to improve the estimation accuracy of rotor position and speed of the PMSM system without position sensors: On the one hand,an adaptive estimation method of Back-EMF(back electromotive force),which could optimize the estimation of motor Back-EMF,is put forward to reduce the system chattering caused by sliding mode control.On the other hand,a phaselocked loop is also adopted to estimate the position and speed of the motor rotor.What's more,a simulation model of the sensorless PMSM system is established in MATLAB/Simulink to verify the estimation performance of the proposed adaptive sliding mode observer.Secondly,the traditional PI regulator is improved based on the fuzzy control principle in this paper.As we know,the optimum parameters of the traditional PI regulator are set off-line according to the structure of the motor controller.In order to adjust the parameters on-line,the fuzzy algorithm is introduced to tune the parameters which are affected by the external environment to ensure the performance of the speed regulator,and thus the system reliability is improved.At last,some simulation experiments are carried out base on the simulation model of the sensorless PMSM system to verify the Fuzzy PI regulator.Finally,some experiments based on the PMSM system platform of 36V/200 W are implemented to verify the feasibility of the proposed algorithm in this paper.STM32F407VGT6 is applied as the main control chip to design the hardware and software of the PMSM system.The results of simulation and experiment show that the combination of adaptive sliding mode observer and fuzzy PI regulator could not only realize parameters online setting of a PI regulator,but also improve the control accuracy of the sensorless PMSM system.