Research On New Control Strategies Of Switched Reluctance Motor Drive System

With its characteristics of simple structure, flexible control, excellent speed regulationperformance, the switched reluctance motor drive system (SRD) integrates the motor theory,modern power electronic technology and automatic control technology as a whole, becomingone of the hottest topics in the current development of electric drive field. However, owing toits double salient pole structure and the switch mode power supply lead to the large torqueripple. Moreover, on account of its serious nonlinear characteristic, control parameters need tobe updated under different rotation speed, resulting in its control strategy being more complex.Therefore, new control strategy of the switched reluctance motor drive system is studied indepth in this paper, in which new control method is used to design the speed controller, thecontrol parameters are updated in real-time, in order to reduce the torque ripple of the motorand improve speed regulation performance.Firstly, this paper introduces the research background and significance of the switchedreluctance motor drive system and main development and research direction at present,particularly the research of torque ripple suppression. Then analysis the basic structure andworking principle of the switched reluctance motor in brief. Then the linear and nonlinearmathematical model of SR motor is established, and the speed characteristics of switchedreluctance motor drive system is described, after that the basic control method of SR motor isanalyzed with its small signal model.In consideration of the nonlinear model and strong coupling point of switched reluctancemotor, this paper adopts a fuzzy adaptive control algorithm, a reluctance motor drive systembased on method of voltage PWM control is built, then the speed controller is designed withthe algorithm, which improves the efficiency and precision of the SR motor compared withconventional fuzzy controller, and the torque ripple is suppressed. Then, a greypredictive control method is applied to the switched reluctance motor drive system onits small signal model, the parameters of uncertain module of the system is estimated byestablishing gray prediction model, predictive compensation is added to the controller in nextseveral steps. The speed tracking and the error change rate of the system are muchsmoother, also the shock and torque ripple are reduced in a large degree, and the robustnessand real-time point is improved.To validate the feasibility and practicability of two methods, simulated system of SRD isdesigned by MATLAB software with SIMULINK platform, and the simulation results withnew strategies are compared with the conventional one, which presents that controller of SRDwith new strategies is feasible and shows good dynamic and static characteristics, and thetorque ripple is also suppressed obviously, and the torque fluctuations is in the reasonablescope in the load disturbance. Specificly, for the performance indicators, each one of twostrategies has its owns points.