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1

Impact of scale factor on performance of miniature DC power source based on wideband vibration energy converter

Kulik Marcin, Górecki Krzysztof, Jagieła Mariusz

Przegląd Elektrotechniczny

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2022

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R. 98, nr 8

185--188

EN

This paper presents a miniature DC source based on a dual system of nonlinear vibration energy converters along with a converter of an induced voltage. The considered electromagnetic system converts vibrations into electrical energy using internal nonlinearity due to magnetic force dependent on relative position of a moving part. This results in a significant widening of the operating frequency band in comparison to linear system. Based on initial design, the output power and voltage were investigated as functions of the scale factor for the systems with the optimized winding. The result of the study is a construction of a DC power source that generates the output power of minimum of 2 mW (with maximum reaching 8.5 mW) over the frequency range between 15 and 40 Hz, proving the applicability of the system in powering of wireless sensor systems.

PL

W pracy zaprezentowano miniaturowe źródło prądu stałego oparte o układ podwójny nieliniowych przetworników energii drgań wraz z przetwornicą napięcia. Zastosowane elektromagnetyczne układy przetwarzające drgania na energię elektryczną charakteryzują się dodatkową siłą wewnętrzną, co powoduje znaczne poszerzenie pasma częstotliwości pracy w stosunku do układów liniowych. Na podstawie początkowego projektu, przeprowadzono badania mocy oraz napięcia wyjściowego w zależności od współczynnika skalującego, z uwzględnieniem optymalizacji rozłożenia zwojów cewek. W wyniku badań zbudowano źródło prądu stałego generujące minimum 2 mW (max 8.5 mW) w zakresie częstotliwości od 15 do 40 Hz, co dowodzi możliwości zastosowania w zasilaniu bezprzewodowych systemów pomiarowych.

2

Area of the unstable solution of rolling equation : jumps of the oscillations amplitude

Wawrzyński W.

Journal of KONES

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2018

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Vol. 25, No. 3

489--496

EN

The most interesting motion of the ship is rolling. This is because the rolling amplitudes are much bigger than amplitudes of other degrees of freedom and under resonance conditions, which can exceed 40º. In such a case, when the maximum of the righting arm curve is placed at relatively small angles, the roll equation reveals a strongly nonlinear character and bistability areas as well as an area of unstable solutions of the roll equation occurs. Together with the appearance of the above-mentioned areas, amplitude jumps are possible. In the study, the case of strongly nonlinear rolling is analysed. For the purpose of numerical simulations, the 1DOF mathematical model of rolling with damping dependent on amplitude and frequency is used. The article presents the roll spectrum including the bistability areas and the area of unstable solutions for one loading condition of the offshore support vessel. It is demonstrated that for strongly nonlinear rolling, rolling with two different amplitudes for the same value of excitation is possible. It is also shown that transitions (jumps) between these amplitudes are possible too. A few scenarios of jumps of the rolling amplitude within the region of unstable solutions of the rolling equation are presented. The presented rolling scenarios show that under some circumstances rolling can be observed as chaotic.

3

Harvesting mechanical vibrations energy using nonlinear electromagnetic minigenerators - a survey of concepts and problems

Kulik M., Jagieła M.

Poznan University of Technology Academic Journals. Electrical Engineering

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2017

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No. 90

347--358

EN

The state of knowledge in the field of conversion of energy of mechanical vibrations into electrical energy using nonlinear electromagnetic generators is presented. The principle of operation of the considered converters is based on the Faraday law. The electromotive force is induced by the relative movement of the coil or permanent magnets under impact of externally applied vibrations. In order to diminish the disadvantages of conventional generators, namely the narrow frequency bandwidth, in recent years the nonlinear systems were introduced that exhibit the nonlinear resonance phenomenon. Broadening the frequency bandwidth, in which the power generated by the system is relatively high, is realized via introduction of nonlinear force into system kinematics. Designing such systems becomes a big challenge. Based on thorough survey of recent publications as well as on own expertise in the field, the work compares a few concepts of nonlinear electromechanical minigenerators in term of their functional characteristics and design problems. Sample calculations of frequency characteristics using time- and frequency-domain models are presented.

4

A way to the engineering of the quantum states of trapped ions – report of work in progress

Stachowska E, Szawiola G, Buczek A, Koczorowski W, Furmann B, Krzykowski A, Staefanska D, Walszyk A, Jarosz A, Dembczynski J

Optica Applicata

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2006

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Vol. 36, nr 4

s. 581--586

EN

We studied the influence of geometry on the interaction of ions in a Paul trap with microwave radiation and the spatial velocity distribution from the Doppler shift. Non-linear resonances in a Paul trap for Pr+ ions were observed.

5

About the properties of attraction sets of two models of physics of the atmosphere

Brojewski R., Jasiński J.

Journal of Technical Physics

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2003

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Vol. 44, no 3

311-328

EN

Dynamical properties of two simple models derived from the equations of physics of the atmosphere are investigated in this paper. Attention was paid to the structure of attraction sets (especially to their borders) of the attractors existing in the models. The influence of precision of the integrating procedures' on some of the attractors identification was investigated. The mechanism of destroying a strange attractor (by the nonlinear resonance) in a Lorenz system with thermal forcing was found.