Research On Sensorless Control Method Of Switched Reluctance Motor

With the continuous development of power electronic technology,the switched reluctance motor is widely used in various fields,reluctance motor has the advantages of simple structure,low cost,flexible control,in some occasions to highlight its advantages,more complex sensorless switched reluctance motor control method to improve the stability of the system,and reduce the cost and complexity of the structure of the control system,has become the research direction and hotspot.Based on the three-phase(6/4)pole switch reluctance motor as the research object,in view of the switched reluctance motor with position sensor and sensorless control method to carry on the detailed introduction,This paper presents a control method to solve the torque ripple problem,and conducts modeling,simulation and experimental analysis of the control system.Firstly,the structure and operation principle of switched reluctance motor are analyzed,the mathematical model is established and the electromagnetic characteristics of the motor are analyzed linearly.On this basis,the simulation model of switched reluctance motor with position sensor based on current chopper control method is built and verified by simulation.Aiming at the problem of the model large torque ripple of direct torque control strategy was proposed,by rotating torque and flux closed-loop control,using the comparison deviation adjustment to determine the magnitude and direction of stator voltage space vector,the power converter control and shutoff and counter rotating moment suppressed,based on direct torque control system model simulation and comparison analysis of torque ripple of direct torque control is verified for torque ripple suppression of good results.Then,two different analysis of the switched reluctance motor speed sensorless control method,within the scope of the low speed range based on phase current gradient Angle estimation,high-speed interval of simplified flux method,using the advantage of the two control methods to establish a full range of sensorless control and modeling simulation analysis,aimed at different speed range of adduction torque pulsation problem put forward the indirect torque control strategy,in the low speed range using the current chopping control method of limiting current amplitude,at a high speed range using the Angle position control method to improve the phase current waveforms,indirectly by adjusting the current to curb the problem of torque ripple.Through modeling simulation and torque ripple comparison analysis,it is verified that the indirect torque control strategy is effective in suppressing torque ripple without position sensor.Finally,based on the hardware experiment platform of switched reluctance motor,I wrote the experimental program and debuggled the hardware,designed the control circuit based on FPGA and built the drive circuit,and simulated and verified the PWM control signal,speed calculation module,commutation logic module and PI control module of the software system.The feasibility of the control method for torque ripple suppression is verified by experiments.