Modeling And Controlling Based On "quasi-equivalent" The DC Motor Double Loop DC Motor Control System With Load Variable

With good starting, braking performance and smooth speed control in a wide range,DC motor has been widely used in the field of electric drive that need for speed controlor fast forward and reverse. With good dynamic performance, the double loop(theSpeed and Current loop) DC motor control system(DLDMCS) become the typicalapproach to compose the DC motor servo drive system.In order to better describe the dynamic response of DLDMCS and optimal control,the mathematical model of DLDMCS need to be established and the optimal controlneed to be implement. In modeling, DLDMCS not only has two cross-loop structure,but also it has the saturated nonlinear in its internal close-loop. The modeling of theclose-loop system with containing saturated nonlinear is always an important researchdirection, and also is the hot and difficult issue in theory. And the variable of the loadaffects the dynamic response characteristics of the DLDMCS, so the effect of loadchanging to model need to be mainly researched. About the optimal control, theresearch how to control the key dynamic performance of the DLDMCS online also hasvery important practical significance.In view of the above question, this paper mainly carried on the following research:①Based on the "quasi-equivalent" modeling, the DLDMCS nonlinear state-spacemodel with load variable and the parameter identification method are proposed. In thedepth analysis of the DLDMCS mechanism, the mathematical relationship between theinertia load and the load current is found, and the system block diagram including theinertia load is established. Base on the block diagram of DLDMCS and the dynamicresponse mechanism, with the "quasi-equivalent" modeling, the DLDMCS withvariable in load is simplified, and the DLDMCS nonlinear state-space model withvariable in load is established. Based on the experimental platform that we development,through the genetic algorithm, the model parameters are obtained.②Analysis on the effect of all the types of load on DLDMCS, the equivalentinertia load analysis method is proposed. Base on the analysis method, the motor systemexperimental platform with the inertia load variable is developed. The method based oncorresponding load current generated by the various types of load transforms all thetypes of load to the corresponding inertia load. So, using the equivalent inertia loadanalysis method, the DLDMCS model with load variable can be transformed to the DLDMCS model with the load inertia. Equivalent inertia load analysis as the theoreticalbasis, the motor system experimental platform with inertia load variable was developed.The inertia load of the platform can be adjusted by change the number of inertia disk, sothe study on the actual dynamic performance of the DLDMCS with load variable iseasy.③Based on the "quasi-equivalent" DLDMCS model, the model parameterscorresponding to the maximum acceleration as the key parameters, the dynamic controlmethod on the key parameters is proposed. And through the new type of DLDMCSdrive that is developed, the dynamic control method on the key parameters isimplemented.