Miroslav Bjekic

Remote control of electromagnetic load emulator for electric motors

This paper presents equipment and application for remote control of electromagnetic load emulator. Emulator is dedicated for testing of electrical motors in laboratory environment. It can emulate different kinds of loads which can be found in industrial environment like pumps, funs, conveyors, elevators etc. The working principle of electromagnetic emulator is based on electromagnetic induction. Emulator control is realized with CompactRIO controller that has a web server so it can be accessed remotely. Programming is done via LabVIEW software.

Influence of use of the MATLAB as underlying technology on development of the curriculum for the course in signals and systems

This paper presents an experience in developing of the new course curriculum for signals and systems theory within the frame of Bologna declaration with emphases on new teaching and learning paradigm. Using of MATLAB software is suggested not only as underlying technology for better understanding of abstract mathematical description of signals and systems analysis and synthesis but also as modern tool for simulations and modelling in all engineering courses and in many engineering tasks.

Using computer for measurement and visualization of rotating magnetic field in AC machines

This paper presents a new way of implementing a computer as a teaching tool in the teaching module “Rotating Magnetic Field in AC machines.” Software for simulation, measurement, and visualization of the rotating magnetic field using three‐axis hall sensor was created in the form of remote experiment. After students’ evaluation, it was found that remote experiments ensure better achievement of students regarding this particular topic, while also contributing to better quality of teaching rotating magnetic fields in the subject of electrical machines.

Educational laboratory setup of DC motor cascade control based on dSPACE1104 platform

This paper presents an educational laboratory setup for real time DC motor cascade control, based on dSPACE1104 platform. The laboratory setting allows consideration of the principles of DC motor control and determination of the parameters of current and speed regulation loops. Detailed description of used hardware (digital controller, the power converter and necessary cards for isolation and signal conditioning) is firstly given, and then the software model of the control structure made within MATLAB / Simulink package. dSPACE controller is linked with the realized Simulink model, which allows easy and rapid creating of the control application (rapid control prototyping) i.e. interaction of the simulation with the real control system. Also, in this way it is possible to easily adjust the controller parameters of current and speed loops and to track the responses of the regulated variables. This paper emphasizes the educational aspect of the realized laboratory setup for DC motor control. Required values of the controller gains for current and speed loop were found by mathematical analysis of the control model and subsequently simulation results were compared with the results obtained experimentally with the real system. In this way, students which attend the course of electric drives control are enabled to better understand the operating principle of modern digital controllers in DC motor control drive. Realized laboratory setup opens the possibility to analyze the energy efficiency of electrical drive depending on the control mode and application of the various control algorithms by rapid prototyping.

Electromotive force compensation in direct torque control with discretized voltage intensities

This paper describes a way of electromotive force compensation in direct torque control algorithm with discretized voltage intensities. Theoretical background of DVI-DTC algorithm with discretized voltage intensities is presented. The main advantage of this algorithm is the change in number of available voltage intensities in order to reduce the torque ripple as required. The effect of induced EMF on torque increments within a single inverter switching cycle is analytically evaluated. The method for compensation of EMF effect with the goal of elimination of torque error in steady state is proposed. Experimental results are shown in the paper to illustrate the response speed of torque control with and without induced EMF compensation.