Research On The Direct Torque Control Technology Of Switched Reluctance Motor

Switched reluctance motor(switched reluctance motor,SRM),as a new type of motor has the advantages of simple structure,low cost,wide speed range,and the advantages of reliable operation,has been widely used in various fields.But the doubly salient structure of switched reluctance motor nonlinear electromagnetic torque and variable parameter characteristic,makes the control difficulty increase,especially prominent is the switched reluctance motor running transfer torque ripple problem.Because of the direct torque control strategy is not sensitive to motor parameter,and the torque,current response is fast,so this article in view of the doubly salient reluctance motor direct torque control strategy launched a series of research and compared with current chopping control strategy,prove that direct torque control strategy to restrain the torque ripple effect is better.Introduce the basic structure and working principle of SRM,according to the switched reluctance motor circuit equations,flux linkage equations,mechanical equations,mechanical and electrical characteristic equation to establish the mathematical model of SRM linear model is established according to the mathematical model,based on linear model analysis of winding flux linkage and phase current waveform,phase inductance,torque calculation.Through the direct torque control theory,the control target is determined,and its principle is analyzed in detail with the direct torque control strategy as the core.For direct torque control and current chopping control strategy in the Matlab/Simulink platform and carry on the simulation,compared to two kinds of control strategies of switched reluctance motor phase current,and the size of the torque ripple,and the size of the torque ripple under load mutation,exploding load speed fluctuation under size,and so on.It is proved that the direct torque control strategy is more effective.Build four phase switch magnetic resistance reluctance motor control system experimental platform,the hardware circuit mainly includes the position detection circuit,drive circuit and PWM generation circuit,and explains the main program of switched reluctance motor software and the working flow of the sub-program of speed measurement and calculation,the optimized parameter modification and application,in the case of constant torque,compared to two kinds of control strategies under the runaway phenomenon and fluctuating torque is bigger,through compared two kinds of control strategies of current PWM control signal,load torque ripple size jump speed pulse size.The results showed that the four phase reluctance motor direct torque control system response speed,good robustness,high control accuracy,high ripple effect,strong anti-interference ability,has excellent dynamic and static performance,verify the feasibility and accuracy of design scheme.