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1

Third harmonic current injection into highly saturated multi-phase machines

Klute F., Jonsky T.

Archives of Electrical Engineering

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2017

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Vol. 66, nr 1

179--187

EN

One advantage of multi-phase machines is the possibility to use the third harmonic of the rotor flux for additional torque generation. This effect can be maximised for Permanent Magnet Synchronous Machines (PMSM) with a high third harmonic content in the magnet flux. This paper discusses the effects of third harmonic current injection (THCI) on a five-phase PMSM with a conventional magnet shape depending on saturation. The effects of THCI in five-phase machines are shown in a 2D FEM model in Ansys Maxwell verified by measurement results. The results of the FEM model are analytically analysed using the Park model. It is shown in simulation and measurement that the torque improvement by THCI increases significantly with the saturation level, as the amplitude of the third harmonic flux linkage increases with the saturation level but the phase shift of the rotor flux linkage has to be considered. This paper gives a detailed analysis of saturation mechanisms of PMSM, which can be used for optimizing the efficiency in operating points of high saturations, without using special magnet shapes.

2

Poprawa właściwości półprzewodnikowych laserów z sekcją trapezową

Belka R.

Elektronika : konstrukcje, technologie, zastosowania

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2003

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Vol. 44, nr 5-6

5-8

PL

Badania nad zwiększaniem mocy laserów półprzewodnikowych są prowadzone od wielu lat. Jedną z prostszych i tańszych metod pozwalających na uzyskanie większej mocy wyjściowej jest modyfikacja kształtu obszaru aktywnego lasera poprzez zastosowanie sekcji trapezowej. W artykule przedstawiono strukturę, własności, i parametry tego typu laserów, a także krótki opis zastosowanej techniki symulacyjnej. Zwrócono uwagę na możliwość poprawy jakości niektórych parametrów poprzez zastosowanie ogranicznika wiązki.

EN

The high-power semiconductor lasers have been investigated for many years. Modification of quantum well shape by adding of tapered section is one of cheaper and easier way to obtaining of larger output power in these laser. I this paper the structure, properties and parameters of tapered lasers, as well as short description of simulation model have been presented. Special attention was paid on improvement of beam properties by using of beam spoiler.

3

Influence of Non-Linear Effects on the Depositions Computed with the EMEP Eulerian Model

Bartnicki J.

Chemia i Inżynieria Ekologiczna

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2001

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Vol. 8, nr 1

61-83

EN

Annual depositions and source-receptor matrices for sulphur, oxidized nitrogen and reduced nitrogen are computed routinely every year at MSC-W in Oslo within the framework of the EMEP Programme. The assumption of a linear relationship between the depositions and emissions allows the use of the source-receptor matrices for the policy purpose and especially for investigating the effects of the emission reduction scenarios in Europe. Although departures from linearity are relatively small, this assumption is not entirely fulfilled in the model equations and in the applications of the model. The analysis of the non-linear effects in the computed depositions is the main subject of this study, which is based on the numerical experiments with the EMEP Eulerian model. The results of the numerical experiments presented in the paper indicate that the uncertainties of the computed depositions and source-receptor matrices due to the non-linear effects are much smaller than other sources of uncertainty. e.g. inter-annual meteorological variability.

PL

Depozycje roczne oraz macierze przejścia dla siarki, azotu utlenionego i azotu zredukowanego są liczone rutynowo w MSC-W w Oslo w ramach programu EMEP. Założenie liniowego związku pomiędzy depozycjami a emisjami pozwala na zastosowanie obliczonych macierzy przejścia do różnych procesów decyzyjnych, a szczególnie do badania efektów ograniczenia emisji w Europie. Chociaż odchylenia od liniowości są niewielkie, założenie to nie jest całkowicie spełnione w równaniach modelu i w jego zastosowaniach. Analiza efektów nieliniowych w obliczonych depozycjach jest głównym tematem tej pracy, która bazuje na eksperymentach numerycznych z Eulerowskim modelem EMEP. Rezultaty eksperymentów numerycznych zaprezentowanych w pracy wskazują na to, że niepewność obliczonych depozycji i macierzy przejścia spowodowana efektami nieliniowymi jest znacznie mniejsza niż niepewność związana z innymi źródłami, np. zmianami meteorologicznymi dla poszczególnych lat.

4

Large Scale Structures in Multicellular Chemical Systems

Maselko J.

Polish Journal of Chemistry

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2000

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Vol. 74, nr 3

311-319

EN

Calculations have led to the discovery of very complex, highly organized and beautiful structures. These structures develop from a single perturbation in 2-D array of chemical cells. The chemistry in every cell is described by the Gray-Scott model, where cells are coupled dy the diffusion of both chemical species. Many of the observed features were never seen in continuous media and may only occur in multicellular chemical systems. Some complex structures are bounded in space, while others are formed close to system boundaries. The characteristic properties are the growth of branches, subbranches and the formation of closed compartments. The influence of symmetry of chemical medium and symmetry of initial perturbations on developed structures is also investigated.

5

Asymmetric multiple quantum well heterostructure laser systems : conception, performance, and characteristics

Kononenko V. K., Afonenko A. A., Manak I. S., Nalivko S. V.

Opto-Electronics Review

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2000

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Vol. 8, No. 3

241-250

EN

A new type of laser diodes and amplifiers based on asymmetric quantum-well heterostructures having active layers of different thickness and / or compositions has been considered. Bistable switching and regimes of regular radiation pulsation at two or three remote wavelengths in the range 790 - 850 nm in the GaAs-AlGaAs bi- and triple - quantum-well heterostructures are described. Influence of non-linear processes including gain suppression due to carrier heating on lasing regimes has been examined. Transformation of gain bands for TE and TM modes in dependence on the pump current has been studied for asymmetric four-quantum-well structures. The interval of tuning amplification wavelengths in the system reaches up to 70 nm.

6

Non-linear effects in spherical particle motion in oscillatory flowing gas

Dolata M., Michalski J.

Polish Journal of Chemistry

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1999

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vol. 73 nr 2

347-357

EN

Basing on the Tchen equation, the dynamic characteristics of a system consisted of a little sphere moving in an oscillatory flowing gas are developed. The conditions of appearance of steady points of solutions (node, focus, saddle) are formulated. Numerical solutions show that an additional attractor (asymptotic trajectory) can be found in this system.