Sensorless Control Of PMSM Based On Sliding Mode MRAS Adaptive Law

Permanent magnet synchronous motor(PMSM)has attracted extensive attention in transportation,industry,robotics and national defense due to its advantages of high accuracy and good dynamic performance of speed and position control.In engineering practice,humidity and vibration have a great impact on the performance of the sensor,so sensorless control algorithm is used to replace the mechanical sensor,in order to simplify the PMSM drive part of the structure is simple,reduce the cost.However,with the development of industrial technology production and life,PMSM can cope with increasingly complex working environment.In order to obtain excellent control performance,more superior control strategy is needed.Aiming at the problems of large dynamic tracking error and poor robustness of the sensorless control of permanent magnet synchronous motor with traditional Model Reference Adaptive System(MRAS),this paper designed a sensorless control of PMSM with improved MRAS Adaptive law.The main research contents are as follows:First,the mathematical model of three-phase PMSM in synchronous rotation coordinate system was established,and a new sliding mode MRAS(SMMRAS)observer was proposed to solve the problems of low parameter,load sensitivity and speed estimation accuracy in traditional MRAS.Firstly,a SMMRAS observer based on a new sliding surface is designed to improve its robustness.Secondly,in order to weaken the chattering of sliding mode,hyperbolic tangent function is introduced instead of sign function.Finally,an integral sliding mode speed controller is designed to improve control performance of the system.Simulation results show that the proposed control method can not only suppress the chattering and signal noise,but also improve the robustness of the system effectively.Second,in order to solve the problem of large dynamic tracking error caused by load,speed and parameter changes in PMSM sensorless control during operation,a MRAS observer based on third-order PI was proposed.The introduction of third-order PI in traditional MRAS can effectively reduce the tracking error in the case of burst disturbance and suppress sliding mode chattering.At the same time,the system has good stability and robustness.By comparing the traditional MRAS with the designed observer,the simulation results show that the designed observer has strong ability to suppress external disturbance,is insensitive to the changes of internal parameters of the motor,has high tracking accuracy,and has obvious jitter weakening.Lastly,the DSP control platform is built,the hardware circuit is designed,the control algorithm program is written in CCS environment,and the digital realization possibility of the control means is proved from the experimental point of view.Figure[38]Table[3]Reference[54]...