ISSN 1805-3386

April 10, 2020


2013 No.3

Induction Motor Design by Use of Genetic Optimization Algorithms

Zablodskiy, N., Lettl, J., Pliugin, V., Buhr, K., Khomitskiy, S.

The problem of the automated calculation and optimal design of an induction motor is presented . The problem of optimization by use of genetic algorithms is set and solved. The analysis of the obtained results is executed.


Keywords: induction motor, optimization, varied variables, genetic algorithm, criteria, limitations, effective variant, EvoJ library


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New Ways of Controlling Dangerous Torsional Vibration in Mechanical Systems

Homišin, J.

In general terms the mechanical systems (MS) mean the systems of driving and driven machines arranged to perform the required work. We divide them into MS operating with constant speed and MS working within a range of speed. In terms of MS dynamics we understand the system of masses connected with flexible links between them, i.e. systems that are able to oscillate. Especially piston machines bring heavy torsional excitation to the system, which causes oscillation, vibration, and hence their noise. Based on the results of our research, the torsional vibration control as a source of given systems excitation, can be achieved by application of pneumatic couplings, or pneumatic tuners of torsional vibration. Existence of pneumatic couplings and pneumatic tuners of torsional vibration developed by us, creates the possibility of implementing new ways of torsional oscillating mechanical system tuning. Based on the above, the aim of the article is to present new ways of dangerous torsional vibration control of mechanical systems by application of pneumatic couplings and pneumatic tuners of torsional vibration developed by us.


Keywords: torsion, oscillating mechanical system, pneumatic coupling, pneumatic tuner of torsional vibration, ways of torsional vibration control


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Experience with Torque Measurement on Rotating Shaft

Folta, Z., Hrudičková, M.

This article deals with problem of torque measurement on the turning shaft and the signal transmission to the measuring equipment. There is described the experience with contact transmission and both non-contact and high frequency transmission (with ESA Messtechnik equipment). Also the examples of the practical realization are presented.


Keywords: Torque measurement, telemetry, strain gauge measurement, experiment


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Performance of Steady-State Voltage Stability Analysis in MATLAB Environment

Veleba, J.

In recent years, electric power systems have been often operated close to their working limits due to increased power consumptions and installation of renewable power sources. This situation poses a serious threat to stable network operation and control. Therefore, voltage stability is currently one of key topics worldwide for preventing related black-out scenarios. In this paper, modelling and simulations of steady-state stability problems in MATLAB environment are performed using authordeveloped computational tool implementing both conventional and more advanced numerical approaches. Their performance is compared with the Simulink-based library Power System Analysis Toolbox (PSAT) in terms of solution accuracy, CPU time and possible limitations.


Keywords: Steady-state voltage stability, continuation load flow analysis, predictor-corrector method, voltage stability margin, voltage-power sensitivity, Power System Analysis Toolbox


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Cross Slide Mathematical Model for Solving Chatter

Ondrášek, J.

The paper deals with the issues of creating a mathematical model of self-excited chatter of the cross slide. This type of oscillation occurs in systems where there is still an internal source from which the system consumes energy to maintain or even to increase the amplitude of oscillation. This consumption is controlled by an oscillatory movement of the system itself. Such an energy source greatly affects the dynamic and stability properties of the system.


Keywords: chatter, cross slide, chip thickness, lobe diagram


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