Experimental dynamometer emulation of non-linear mechanical loads

Industrial processes often contain nonlinear mechanical loads driven by electrical drives. PI and PID controllers, widely used in industrial drives, may not give satisfactory results for some nonlinear loads since they are linear controllers. Adaptive, robust and intelligent nonlinear control methods are attracting considerable attention to design a good controller for these nonlinear mechanical loads. As far as research is concerned, it is not practical to have different kinds of linear or nonlinear mechanical loads in the laboratory. The solution is to have a programmable load emulator (dynamometer) to provide realistic nonlinear loads for the experimental validation of advanced control techniques in the laboratory. This paper describes a dynamometer control strategy in which the emulation preserves the dynamic structure of a desired load model so that the emulation can be used in closed loop control. Experimental results of the closed loop control of some nonlinear loads are presented. Computer simulation results are also provided for comparison purposes to show the performance of the proposed load emulation method.