Research On Method Of Mover Position Sensorless Detection For Planar Switched Reluctance Motor

The planar switched reluctance motor(PSRM)using electromagnetic energy to achieve two-dimensional direct drive,PSRM is a new type of special planar motor and will have good development prospect.So far,The PSRM is mainly used grating-rule sensor to obtain the position information of the mover.However,the grating-rule sensor makes the system cost high and reduces the reliability of the system,due to its high cost.Therefore,it is of great academic significance and potential application value to explore the sensorless mover position detection method of the PSRM.In this paper,the working principle of the PSRM is described,the basic structure of the PSRM is given,and the mathematic model of the PSRM is built.A scheme of the sensorless position detection system for the PSRM is constructed.Based on dSPACE,the semi physical structure block diagram of the sensorless position detection system for the PSRM is established.Aiming at the structural and electromagnetic characteristics of the PSRM,Based on the current injection method,a sensorless mover position detection method is presented.In order to lay the theoretical foundation for further research of the initial position detection and the position detection of the low speed operation,the principle of position detection is given,the theoretical value range of injected current amplitude and frequency is deduced.Aiming at the initial position detection of the PSRM,a method for detecting the initial position of the PSRM is presented based on current injection.The mathematical relationship between the response voltage and inductance of the winding is analyzed in detail.The principle and process of initial position detection is introduced.Considering the hardware resource factors in actual system,the spectrum analysis of the motor drive is carried out by using the dynamic signal analyzer,so the actual range of injected current amplitude and frequency is obtained.Based on the ANSYS Maxwell electromagnetic simulation software and Simplorer multi domain electromechanical system simulation software,the initial position detection simulation system is constructed.Based on dSPACE,the initial position detection system of the PSRM is built.The proposed method is validated by using this system.Simulation results show that the initial position error of the X axis and the Y axis both in the range of [-0.086,0.1]mm,experimental results show that the initial position error of the X axis is in the range of [-0.2383,0.1557]mm,the initial position error of the Y axis is in the range of [-0.2213,0.1172]mm,both simulation results and experimental results validate the feasibility and effectiveness of this method.In order to realize the position detection of the low speed operation,a method for sensorless position detection based on current injection is presented.The principle of position sensorless position detection of the PSRM in low speed operation is analyzed.Combined with the excitation rules of the PSRM,the basis for the selection of the conducting winding and non-conducting winding are given.Based on the ANSYS Maxwell and Simplorer,the simulation system for the position sensorless detection of the PSRM is developed.Based on dSPACE,the position sensorless detection system of the PSRM is designed.Simulation and experimental results show that the position detection accuracy is proportional to the frequency of the detected current and inversely proportional to motor speed.The simulation results show that the maximum error of X axis and Y axis is 0.4821 mm,experimental results show that the initial position error of the X axis is in the range of [-0.9966,1.332]mm,the initial position error of the Y axis is in the range of [-0.7432,1.179]mm.The detection position is consistent with the actual position,the mentioned method is validated.In summary,in this paper,a method based on current injection method is presented to detect the position of the initial position and sensorless position detection method for the PSRM with low speed operation.The initial position detection and sensorless position detection under the low speed operation is realized,promote the development of the PSRM technology.