| With the country’s continuous attention and investment in the field of new energy,the development of new energy technology is also changing rapidly.Permanent magnet synchronous motor has been widely used in the field of new energy vehicles and aerospace because of its unique advantages plus continuous development and innovation.In some environmentally constrained applications,the use of position sensors is often inconvenient and costly,so often choose positionless control technology,can effectively reduce the cost and system size,and at the same time can not be affected by the external environment.Position-free control has become the focus of current research in the field and has received attention from scholars at home and abroad.Aiming at achieving positionless sensorless control at full speed,this paper comprehensively uses vector control strategy,high-frequency pulse signal injection method and sliding mode observer-based method,and the main work is summarized as follows:First,the target of selecting a surface-mounted permanent magnet synchronous motor is chosen,and the method of_di(28)0 in vector control is used for control.This involved analyzing and establishing a relevant mathematical model,and introducing and implementing space vector pulse width modulation technology(SVPWM).The resulting model was then built and analyzed through simulation in Matlab/Simulink.Secondly,at zero low speed,the salient polarity formation principle of SPMSM is introduced first,and the high-frequency pulse signal injection method is selected to realize the control at zero low speed by using the salient polarity.In order to improve the control accuracy and performance of the traditional high-frequency pulse voltage method,it was decided to use the adaptive filter to extract the amplitude signal containing the motor position information and to discriminate the rotor polarity.This method is effective in reducing errors and improving accuracy in estimation.The traditional algorithm and the improved algorithm were both simulated on Matlab/Simulink,with the effectiveness of the improvement being proven through comparison of the simulations.Then for medium and high speed,the sliding mode observer method is selected for control.The basic principle of the traditional sliding mode observer method is introduced and analyzed,and in view of the problems of jitter and phase delay in the traditional sliding mode observer method,this paper adopts the scheme of improving the sliding mode observer to improve it,which can effectively improve the estimation accuracy of the control scheme.At the same time,a sliding mode controller is also adopted on the speed ring,forming a double sliding mode control to further improve the control effect.On Matlab/Simulink,the traditional algorithm and the improved algorithm in this paper are simulated accordingly,and the effectiveness of the improved scheme is proved by simulation comparison.In order to achieve control at full speed,the weighted average algorithm is selected to combine the zero low speed with the medium and high speed algorithm,and then the effectiveness of the scheme is verified by simulation as well.Finally,a hardware experimental platform is set up with DSP28335 as the main control chip,and the corresponding hardware circuit and software operating plan is presented.Through experiments,the effectiveness and practicability of the proposed scheme are further proved. |
