Research On Position Sensor-less Control Of PMSM Based On High-Frequency Square-Wave Injection And Sliding Mode Observer

Permanent Magnet Synchronous Motor(PMSM)has the advantages of small volume,strong reliability,high power density and good running performance,so it is widely used in AC drive field such as industry,transportation and household appliances.The sensor-less control technology are consistently popular with control research.Therefore,this thesis with the demand of sensor-less control and practice experience,we research the Interior Permanent Magnet Synchronous Motor(IPMSM),and to research the control technology of IPMSM position sensor-less control.This thesis first by studying the mathematical model of permanent magnet synchronous motor,the vector control of permanent magnet synchronous motor control constant air-gap flux linkage control and direct torque control of the technical performance analysis and comparison,and design the control strategy of permanent magnet synchronous motor control,the use of zero d shaft double closed-loop vector control strategy,rotational speed for the outer ring,the current for the inner ring.And then combined with the actual demand and control requirements,for the counter electromotive force of the permanent magnet synchronous motor is not easy to detect while motor running in low speed,and high frequency signal injection method is used to detecting the rotor position,given the traditional high frequency signal injection method used more filter effects in processing system response to this point,to improve its high frequency square wave voltage signal injection method is used to realize the detection of rotor position information,from the point of comprehensive performance comparison,high frequency square wave control effect is better.Using the sliding mode observer of the permanent magnet synchronous motor sensor-less control method while running at a high speed,to extract counter electromotive force which contains the location information of permanent magnet synchronous motor,phase-locked loop is used to realize the rotor position detection,and the switch function of the sliding mode surface was improved to weaken the chattering phenomenon inherent to the sliding mode variable structure.Finally,this thesis adopts the method of the study of the control and use the MATLAB/SIMULINK simulation software platform to complete the design of the control system of permanent magnet synchronous motor without position sensor based on high frequency square wave injection and sliding mode observer.The simulation run and to compare the simulation results.The simulations reveal that PMSM position sensor-less control system can switch from low speed to high speed quickly and stably at full speed and can track the rotor position information effectively and quickly.Control performance of the system is superior and operation is reliable.