| Switched reluctance motors are widely used in energy,textile,aerospace,transportation and other fields due to their low material cost,high mechanical strength,adaptability to harsh working conditions,and flexible control methods.However,due to the structure of the double salient poles of the stator and rotor and the strong nonlinear characteristics of the system,the torque ripple is large and accompanied by strong noise,which limits its application scenarios.Therefore,this article aims to reduce the torque ripple of the switched reluctance motor and reduce the total cost of the system,and conducts a research on the speed control technology of the switched reluctance motor based on the combination of bus current sampling and advanced control methods.In order to simplify the wiring structure of the switched reluctance motor speed control system and reduce the cost of the hardware system,a DC bus current sampling scheme is proposed.In order to explore the theoretical basis of the scheme,the feedback current obtained from the current sensor installed at the DC bus is carried out.Specific analysis,discusses the corresponding relationship between the bus current and the phase current in single conduction and two-phase conduction operating states.Aiming at the current overlap problem existing in two-phase conduction,a method based on an improved torque distribution function is proposed.In order to reduce the impact of overlapping currents,this method is different from the traditional reconstruction of phase currents.It uses the idea of torque distribution function to eliminate the overlapping sudden current problems in the commutation interval and the torque pulsation caused by changes in the flux linkage.The problem combination is to obtain an improved torque distribution function problem,and then the current overlap problem can be effectively solved.Aiming at the torque ripple problem of switched reluctance motors,based on the DC bus current sampling method mentioned above,a speed control scheme of switched reluctance motors combining auto-disturbance control technology and anti-saturation PID control is proposed.By analyzing the mathematical model of the switched reluctance motor,an auto-disturbance-rejection speed controller adapted to the model is designed,and based on the mathematical model corresponding to the specific physical meaning of the auto-disturbance-rejection structure,the parameter adjustment basis is given for subsequent adjustments.Participation provides convenience.Aiming at the various defects of traditional current hysteresis control,this paper adopts the anti-saturation PID structure as the current loop controller,which not only makes full use of the working performance of the controller and motor drive circuit,but also makes it easier to implement on mainstream embedded controllers.Finally,a simulation model and experimental platform for auto disturbance rejection control speed regulation of switched reluctance motor based on bus current sampling are built.The simulation model of the scheme proposed in this paper was built through Simulink software and the feasibility of the scheme was verified.Using the automatic code generation function,the model code was uploaded to the DSP control board and based on this,a set of 12/8 switched reluctance motor hardware experiment platform was built and the actual effect of the scheme was verified.The simulation and experimental results show that: Compared with the traditional PID-hysteresis control method,this scheme has higher robustness and lower torque ripple.The paper has 65 figures,6 tables and 73 references. |
