| Switched reluctance motor have attached much attention in modern electrical control,because of its simple structure,good speed regulation performance and low-cost.But as the result of double salient pole motor structure and nonlinear characteristics of local saturation of flux linkage the torque ripple is becoming seriously.For this drawback,this paper has implemented the studies of low torque ripple on SRM from the aspects of nonlinear modeling a nd control strategy.In the aspect of nonlinear modeling,the four-phase(8/6 pole)switched reluctance motor model has been set up by using Ansoft Maxwell firstly and analyze it in 2 dimensional finite element analysis.In this way the simulation diagrams of magnetic field distribution and flux linkage have been found.After that it introduces the measurement and computing methods of flux linkage,using DSP to measure the flux linkage.On the base of flux linkage results,choose the appropriate mathematical model to build nonlinear model.Meanwhile,compared with the actual flux linkage to indicated the availability of the model.After consult the literature and analyze the control strategy,the mind of direct torque control which apply to the SRM has been presented.The working principle of direct torque control has been got by analyzing torque equation.At last,the Nonlinear model has been applied to the direct torque control system.Compare diagrams of flux and torque with diagrams which got from traditional control method.From this,the direct torque control have a good performance on suppress the torque ripple can be inferred.Set up the experimental platform is on base of simulated analysis.Adding the nonlinear model into the direct torque control to replace the expensive torque sensor.In the experiment,the hardware of electric drive system has been designed to match with software program.Compared the experiment waveforms with simulation waveforms,I can complete the study of torque ripple. |
