**6. Conclusion**

The chapter describes principles and methodology of virtual models development in GUI MATLAB for few chosen electrical machines and controlled drives. The models perform analyses of real machines and drives in various working points and they enable easily to show system performance in various working points and to analyze influence of variable system parameters, modes of supply, and control parameters to system behavior. Presented virtual models have been of various complexity – the simpler ones enable virtual analysis of electrical machines and more complex virtual models also deal with algorithms for synthesis of drive controllers.

Strong advantage of developed virtual models consists in the fact user does not need to know the complexity of dynamical system whose simulation scheme is working in the background. He changes only system parameters, selects input signals (shape and amplitude of reference values, forcing and load signals), select mode of calculations and outputs (graphs displaying). The parameters of virtual models can be changed by a slider or by editing numerical values in editable boxes.

Based on the procedure a whole series of virtual models designed in GUI MATLAB has been developed at the authors' institution in recent years which are partly accessible trough the website of the Virtual Laboratory for Control of Mechatronic Systems (KEM TU Kosice, 2010). The virtual dynamical models contribute to e-learning support at teaching and they also serve for preparation of students for laboratory experimentation. Their utilization makes more attractive lectures and considerably enhances explanation of systems properties. By simulation model students generally easier understand physical processes and they are better prepared to the laboratory work.

Shortcoming of developed models consists in the fact they run on computers having installed the MATLAB program. To overcome this, recently our work was concentrated to applications of the MATLAB Compiler to develop excecutable files. It should be noted that this application enables to run MATLAB operation without simulation (i.e. without a Simulink scheme), without 3D virtual reality views and without animation. The advantage on one side makes development of virtual models more difficult using more complex mathematical subroutines. Also some known problems with GUI MATLAB should be noted - cross platform appearance may not be the same and during the GUI development, often must be used tricks and somehow unfriendly techniques.
