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1

Design and analytical calculations of the width and arrangement of quantum well and barrier layers in GaN/AlGaN LED to enhance the performance

Sharma L., Sharma R.

Opto-Electronics Review

|

2021

|

Vol. 29, No. 4

141--147

EN

This research paper discusses an analytical approach to designing the active region of light emitting diodes to enhance its performance. The layers in the active region were modified and the effects of changing the width of quantum well and barrier layers in a multi-quantum light emitting diode on the output power and efficiency have been investigated. Also, the ratio of the quantum well width to the B layer width was calculated and proposed in this research paper. The study is carried out on two different LED structures. In the first case (i.e., first structure), the width of the quantum well layers is kept constant while the width of the B layers is varied. In the second case (i.e., second structure), both the quantum well and B layer widths are varied. Based on the simulation results, it has been observed that the LED power efficiency increases considerably for a given quantum well to B layers width ratio without increasing the production complexity. It is also seen that for a desired power efficiency the width of quantum well should be between 0.003 μm and 0.006 μm, and the range of B width (height) should be 2.2 to 6 times the quantum well width. The proposed study is carried out on the GaN-AlGaN-based multi-quantum well LED structure, but this study can be extended to multiple combinations of the semiconductor structures.

2

Power-aware scheduling of data-flow hardware circuits with symbolic control

Özbaltan Mete, Berthier Nicolas

Archives of Control Sciences

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2021

|

Vol. 31, No. 2

431-446

EN

We devise a tool-supported framework for achieving power-efficiency of data-flow hardware circuits. Our approach relies on formal control techniques, where the goal is to compute a strategy that can be used to drive a given model so that it satisfies a set of control objectives. More specifically, we give an algorithm that derives abstract behavioral models directly in a symbolic form from original designs described at Register-transfer Level using a Hardware Description Language, and for formulating suitable scheduling constraints and power-efficiency objectives. We show how a resulting strategy can be translated into a piece of synchronous circuit that, when paired with the original design, ensures the aforementioned objectives. We illustrate and validate our approach experimentally using various hardware designs and objectives.

3

Technologie ORC – przegląd rozwiązań i możliwości zastosowania w obszarze skojarzonego wytwarzania energii elektrycznej i ciepła

Kochaniewicz Andrzej

Energetyka

|

2020

|

nr 9

433--439

PL

W artykule dokonano przeglądu rozwiązań i możliwości zastosowania technologii ORC (ang. Organic Rankine Cycle) dla skojarzonej produkcji energii elektrycznej i ciepła. Technologia ORC opiera się na takich samych zasadach działania jak w przypadku klasycznego obiegu Clausiusa Rankine’a, tzn. zachodzą w nim takie same przemiany termodynamiczne, różnica polega jedynie na zastosowaniu czynnika niskowrzącego. W artykule skupiono się głównie na gotowych i sprawdzonych rozwiązaniach dostawców tego typu układów. Dokonano porównania konfiguracji dla układów tego typu, jak również przedstawiono możliwość ich zastosowania w celu optymalizacji wytwarzania energii elektrycznej i ciepła. Główna zaleta technologii ORC to możliwość zastosowania jej w różnych gałęziach gospodarki. Dostępna na rynku komercyjna technologia opiera się głównie na układach ORC zasilanych kotłami na biomasę. Dla tej technologii dokonano syntetycznego zestawienia gotowych rozwiązań, w tym typoszeregów dostępnych mocy elektrycznych i cieplnych w układzie skojarzonym oraz dodatkowo mocy elektrycznej i sprawności elektrycznej w układzie kondensacyjnym. W artykule poruszono także aspekt ekonomiczny związany z nakładami inwestycyjnymi na tego typu rozwiązania, dla których wykreślono charakterystyki kosztowe.

EN

The article presents an overview of solutions and applicability of the ORC (Organic Rankine Cycle) technology in combined heat and power generation. The ORC technology is based on the same principles of operation as in the classic Clausius Rankine cycle, i.e.: the same thermodynamic transformations occur. The only difference is the application of a low-boiling agent. The article mainly focuses on the ready and proven solutions used by suppliers of systems like that. A comparison is made of configurations for this type of systems and, moreover, their possible use to optimize electric power and heat generation is presented. The basic advantage of the ORC technology is possibility of its application in various sectors of the economy. The commercial technology offered on the market is generally based on ORC systems supplied by biomass-fired boilers. The article provides a synthetic list of ready solutions for this technology, including types of available electric and thermal power in combined systems and, additionally, of electric power and electric efficiency in condensing systems. Besides, the article mentions an economic aspect related to capital expenditures for the presented solutions and provides the corresponding cost estimates.

4

Experimental investigation of a centrifugal pump hydraulic performance in hydraulic transmission of solids

Barmaki Reza, Ehghaghi Mir

Mechanics and Mechanical Engineering

|

2019

|

Vol. 23, nr 1

259--270

EN

In petroleum and mine industries, the centrifugal pumps were used for transferring solid particles with water. This method is preferable to other methods because of its user friendly and economic issues. In this article by selecting a proper pump and designing test circuit,we conducted hydraulic tests for water and water mixture with solid particles. For this purpose, an experimental set-up of centrifugal pump with only water and water with solid particles was developed. Then by analyzing the test results and efficiency equation, optimal coefficients of head loss is provided to improve the pump efficiency during hydraulic transmission of solids. The experimental results of power consumption, head, and pressure difference measurements in solid-liquid systems are presented. The experimental set-up results are compared with simulation and numerical one, which show a good agreement with them. It reveals that by adding the solid particles and increasing the fluid density up to 15%, the consumed power increases by about 20%, which result in dropping the efficiency of hydraulic system up to 6%. Finally, the optimal components for developed cycle presented for evaluation the various configuration and hydraulic analysis of pure flow and flow with solid particles in various applications to enhance the most achievable efficiency.

5

Laboratory Tests of a Speed Control System for Roadheader Cutting Heads

Joostberens J., Heyduk A.

Multidisciplinary Aspects of Production Engineering

|

2018

|

Vol. 1, Iss. 1

153--159

EN

The paper presents selected results of the laboratory tests of the speed control system for the R-130 roadheader with an inverter-fed cutting heads drive. The results recorded for the variable speed system have been compared with the measurement obtained for the network supplied drive. There have been noticed some oscillations after rapid current overloads. They are due to the operation of the internal current controller of the PWM-inverter, The oscillations are fast decaying - so they prove the results of initial system stability checking. Generally, the automatic speed control, tracking the optimum speed level calculating by supervisory speed adjuster makes possible to better utilize the motor power throughout the whole cutting time. The better operating conditions of the motor cause increase in the whole system power efficiency (even in spite of additional losses in the inverter circuit) Additionally the sped control reduces dynamical overloads. This fact can have a positive influence on the whole system reliability. The speed control subsystem is a part of the whole control system which contains also close-loop boom angular position and velocity control circuits.

6

Determination of power parameters of switched reluctance motor based on instantaneous values of phase voltages and currents

Qawaqzeh M.Z., Prus V., Kalinichenko A., Zagirnyak M.

Przegląd Elektrotechniczny

|

2016

|

R. 92, nr 12

101--104

EN

An approach to determination of power efficiency of a switched reluctance motor (SRM) based on indirectly measured value of the torque is substantiated. A method for indirect determination of electromagnetic torque with the use of the results of measuring the instantaneous values of phase currents and voltages is presented. The most efficient and the factual angles of phase switching for the analyzed four-phase 8/6 SRM are determined. Comparison of SRM torque values obtained by calculation and by experiment is performed. Efficiency of the analyzed SRM is assessed on the basis of calculated values of the torque.

PL

W pracy wykazano, że podejście do wyznaczenia współczynnika sprawności silnika z przełączalną reluktancją w oparciu o niebezpośrednio mierzone wartości momentu jest uzasadnione. Przedstawiono metodę niebezpośredniego wyznaczenia momentu elektromagnetycznego poprzez pomiary chwilowych wartości prądu i napięcia fazowego. Wyznaczono najbardziej efektywne i faktyczne kąty przełączania fazy w czterofazowym silniku 8/6. Porównanie wartości momentu uzyskanego w obliczeniach i poprzez eksperyment wskazuje na to, że sprawność badanych silników może być oceniana w oparciu o obliczane wartości momentu.

7

The energy efficiency and ecological benefits of low-power furnaces powered by secondary biofuel

Swat M.

Problemy Eksploatacji

|

2016

|

no. 4

127--139

EN

The application of FAME obtained from was te vegetable oil has become a very attractive fuel, because, apart from being an energy carrier, it is also a solution for burdensome waste. Based on conducted research, the author presents the influence of FAME on the basie operational parameters of a low-power furnace. The following parameters were analysed: the air excess factor, the temperature of exhaust gases, and the concentration of toxic compounds in exhausts during the combustion process. The thermal energy was measured both for FAME and for its mixtures with heating oil. The appropriately applied combustion conditions as well as suitable composition of the fuel provide an ecological and effective supply for commercial low-power furnaces.

PL

Zastosowanie FAME pochodzącej z odpadowych olejów roślinnych jako paliwa nabiera coraz większego znaczenia, ponieważ oprócz tego, że może być źródłem energii - rozwiązuje również problem utylizacji uciążliwych dla środowiska odpadów. Na podstawie przeprowadzonych badań określono wpływ FAME na przebieg podstawowych parametrów procesu spalania w urządzeniu kotłowym małej mocy. Określono zmiany współczynnika nadmiaru powietrza, zmiany temperatur gazów spalinowych, zmiany stężeń toksycznych składników spalin w trakcie procesów spalania. Ustalono ilości energii cieplnej wytworzonej w instalacji kotłowej w trakcie spalania FAME i jego mieszanin paliwowych z olejem opałowym. Kontrolowane zmiany parametrów procesowych warunków spalania FAME i wybranych mieszanin z olejem opałowym pozwalają na ekologiczne prowadzenie procesów spalania w komercyjnych kotłach małej mocy.

8

Power efficiency of power plants on trailing suction hopper dredgers

Bocheński D.

Journal of Polish CIMEEAC

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2016

|

Vol. 11, no 1

7--12

EN

This paper presents the notion of operational power efficiency and compares it with the classical definition of power efficiency. There are presented also calculation results of power efficiency for a selected suction hopper dredger and also influence of power system type of suction hopper dredger on magnitude of power efficiency of its power plant has been highlighted.

9

Tramwaj z superkondensatorowym zasobnikiem energii - ocena efektywności algorytmu sterowania

Drozd M., Kobos W., Chudzik P.

Maszyny Elektryczne : zeszyty problemowe

|

2015

|

Nr 2 (106)

171--177

PL

W artykule przedstawiono strukturę superkondensatorowego zasobnika energii przeznaczonego do ograniczania strat w napędach pojazdów trakcyjnych, który został zamontowany w zmodernizowanym tramwaju 105N w Łodzi.. Omówiono założenia algorytmu sterowania oraz zamieszczono przebiegi wybranych prądów i napięć zasobnika oraz pojazdu. W pracy zamieszczono analizę wybranych stanów pracy urządzenia i wyjaśniono metodykę dokonywanych pomiarów.

EN

Article presents structure of a ultracapacitor energy storage designed to reduce energy losses In drives of traction vehicles, which was installed in the modernised tram 105N type in the city of Lodz. Article also discusses the assumptions of the control algorithm and contains waveforms of selected currents and volta ges of the storage and the vehicle. The following paper presents analysis of selected operating conditions and explains the methodology of the measurements carried out.

10

Symulator pulpitu maszynisty

Ciszewski T., Nowakowski W., Wojciechowski J.

Logistyka

|

2015

|

nr 4

2819--2824, CD2

PL

Uniwersytet Technologiczno-Humanistyczny im. Kazimierza Pułaskiego w Radomiu wraz z partnerem firmą MEDCOM Sp. z o.o. z siedzibą w Warszawie zrealizował projekt pt. „Organizacja i wyposażenie laboratorium systemów sterowania pojazdów szynowych współpracujących z fotowoltaicznym układem zasilania” dla Ukraińskiej Akademii Transportu Kolejowego w Charkowie. Projekt jest współfinansowany w ramach programu polskiej współpracy rozwojowej przez Ministerstwo Spraw Zagranicznych RP. W projekcie przewidziano wyposażenie laboratorium systemów sterowania i diagnostyki pojazdów szynowych w nowoczesny symulator pulpitu maszynisty. Projekt symulatora obejmował nie tylko praktyczną konstrukcję obwodów elektrycznych systemu TCMS, ale także programową i sprzętową symulację wybranych systemów i magistral pociągu oraz przygotowanie oprogramowania sterującego. Powstałe w rezultacie urządzenie pozwala na kształcenie studentów w zakresie poznawania budowy i zasady działania systemów sterowania i diagnostyki pojazdów szynowych, obsługi pulpitu maszynisty elektrycznego zespołu trakcyjnego oraz nauki programowania specjalizowanych sterowników PLC.

EN

Kazimierz Pulaski University of Technology and Humanities in Radom in cooperation with MEDCOM Ltd, Warsaw, carried out a project "Organizing and equipping the laboratory of TCMS (train control and monitoring system) of railway vehicles cooperating with photovoltaic power supply" for the Ukrainian Academy of Railway Transport in Kharkov. The project was co-financed by the Ministry of Foreign Affairs of the Republic of Poland within the development cooperation programme. The project goals were to create and equip a rolling stock diagnostic control systems laboratory with the most updated training simulator. The project of the simulator included not only practical design of electrical circuits, but also software and hardware simulation of selected train systems and buses as well as arrangement of the control software. In effect, newly established device give the opportunity to educate students in the field of construction and operation of control systems and diagnostics of rail vehicles and specialized learning PLC programming.

11

Thermodynamic analysis of a co-generation system with a high-temperature gas cooled nuclear reactor

Hanuszkiewicz-Drapała M. J., Jędrzejewski J.

Journal of Power Technologies

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2015

|

Vol. 95, spec.

32--41

EN

This paper presents a proposal for a power system with a helium-cooled high-temperature nuclear reactor (V/HTR) used to generate heat and electricity. Heat is supplied to the technological system completing a sulphur-iodine cycle for hydrogen production. The amounts of heat and the values of the carrier temperature required at individual stages of the cycle are known. Helium energy is additionally used for electricity generation: directly – using a gas turbine and indirectly – in two steam systems. One of them uses water vapour as the working medium. In the other (the ORC system) – a low-boiling fluid is used. The paper presents results of the system multivariate thermodynamic analyses performed using the EBSILON software package. The aim of the calculations is to investigate the impact of selected characteristic parameters of fluids and the ORC system fluid types on the power efficiency of the heat and power plant system and on the total power efficiency of the system, taking the produced hydrogen chemical energy into account.

12

Efficient Performance and Lower Complexity of Error Control Schemes for WPAN Bluetooth Networks

El-Bendary M. A. M., El-Tokhy M. A. R.

Journal of Telecommunications and Information Technology

|

2014

|

nr 4

100--107

EN

This paper presents a new technique of reduction retransmission time by decreasing the discarded packets and combating the complexity through error control techniques. The work is based on Bluetooth, one of the most common Wireless Personal Area Network. Its early versions employ an expurgated Hamming code for error correction. In this paper, a new packet format using different error correction coding scheme and new formats for the EDR Bluetooth packets are presented. A study for the Packet Error Probability of classic and Enhanced Data Rate (EDR) packets is also presented to indicate the performance. The simulation experiments are performed over Additive White Gaussian Noise (AWGN) and Rayleigh flat-fading channels. The experimental results reveal that the proposed coding scheme for EDR packets enhances the power efficiency of the Bluetooth system and reduce the losses of EDR packets.

13

Recycling of warmth spirit bards to increase power efficiency of its processing

Korotinsky V., Tanaś W., Szymanek M., Mihaduk A., Garkusha K., Siniakov A.

Journal of Research and Applications in Agricultural Engineering

|

2014

|

Vol. 59, nr 1

68--71

EN

Article contains materials on increase of power efficiency of use of spirit bards in republic Belarus.

PL

Artykuł zawiera materiały o podwyższeniu energetycznej wydajności wykorzystania wywaru gorzelniczego w Republice Białoruskiej. Jednym z najbardziej efektywnych sposobów podwyższenia sprawności energetycznej przetwarzania wywaru gorzelniczego jest wykorzystanie ciepła wewnętrznego wywaru przed jego obróbką do podgrzewania zacieru.

14

Automatyka budynkowa w realizacji systemów smart grid - energooszczędność i integracja na poziomie odbiorcy energii

Ożadowicz A.

Wiadomości Elektrotechniczne

|

2013

|

R. 81, nr 11

38--42

PL

Przedstawiono problematykę dotyczącą możliwości zastosowania systemów automatyki budynkowej jako elementu poprawy efektywności energetycznej budynków poprzez integrację i sterowanie różnych urządzeń tworzących ich infrastrukturę.

EN

The paper presents issues concerning the possibility of using building automaties systems as element of building power efficiency improvement by integration and control of individual eąuipment forming their infrastructure.

15

Energy and resource saving control system for pumping stadion

Zagirnyak M., Korenkova T., Alieksieieva I.

Przegląd Elektrotechniczny

|

2013

|

R. 89, nr 2b

76--79

EN

Energy and resource saving control system for pumping station is offered. Its formation is based on a complex approach to the estimation of power processes in all the elements of power channel, taking into account the real conditions of consumer operation and changing operating characteristics of hydraulic equipment. The system enables substantiation of the choice of power efficient operation conditions and expedience of hydraulic equipment further operation.

PL

Artykuł dotyczy zagadnienia oszczędności energii I zasobów w stacji pomp, poprzez zastosowanie proponowanego systemu sterowania. Przy jego opracowywaniu zastosowano złożony sposób estymacji procesów energetycznych, biorący pod uwagę zarówno rzeczywiste warunki poboru przez odbiorcę jak i zmienną charakterystykę pracy urządzeń hydraulicznych.

16

Investigation and Study of Mode Splitting in Near Field Inductive Communication Systems

Thanh H. D., Agbinya J. I.

International Journal of Electronics and Telecommunications

|

2013

|

Vol. 59, No. 2

185-194

EN

Frequency splitting is a near field inductive communication phenomenon where the resonant frequency divides into many separate frequencies or to different modes. In this paper, we show that this phenomenon depends on the coupling coefficients or the natural response of the circuit by using the circuit theory to derive these splitting frequencies. Also, the rules for the general matrix that is used to solve for splitting frequencies are also demonstrated clearly. Mode splitting is observed for peer-to-peer, three coils and four coil systems due to the existence of the nearest and second neighbour interactions. In particular, two, three and four modes have been analysed for two, three, and four coil systems respectively. However, the number of modes for these systems can be changed according to the degree of coupling. The differences in the resultant splitting frequencies with and without the second neighbour interaction are shown in the simulation results. Furthermore, we assess the system performances regarding to power efficiency through the inductive transfer functions. Besides, either coupling coefficients at resonance or the simplified transfer functions in some specific scenarios can be obtained by having an insight into these transfer functions. Finally, we recognise and propose that splitting frequency phenomenon can be deployed to transmit signals at many frequencies concurrently.

17

Analiz ekonomiceskoj effektivnosti realizacii programy energosberezenia v Ukraine

Bondar E., Geller E.

Budownictwo o Zoptymalizowanym Potencjale Energetycznym

|

2013

|

nr 2(12)

9--14

RU

V stat’e v sootvetstvii s energeticeskoj strategiej razvitii Ukrainy provoditsa analiz effektivnosti realizacii postavlennyh zadac vo vremeni. Predstavlautsa ekonomiceskie pokazateli razvitia Ukrainy.

EN

In the article in accordance with power strategy development of Ukraine was conducted analysis of efficiency of realization of the put tasks in time. Economic indicators over are brought development of Ukraine.

18

Wykorzystanie biogazu w energetyce zawodowej w korelacji z energetyką jądrową

Brożek M.

Przegląd Elektrotechniczny

|

2012

|

R. 88, nr 2

227-229

PL

Synergia jądrowo – biogazowa jest propozycją działań dla energetyki, z uwzględnieniem specyfiki polskich warunków, gospodarczych, ekonomicznych i technicznych. W artykule podjęta została próba innowacyjnego spojrzenia na możliwości połączenia, dwóch różnych sposobów wytwarzania energii elektrycznej. Z pozoru nie mające cech wspólnych dziedziny, takie jak elektrownie jądrowe oraz systemy przetwarzania biomasy z pozyskiwaniem biogazu, mogą po głębszych i bardziej zaawansowanych analizach, okazać się jednym z atrakcyjnych kierunków rozwoju polskiego systemu elektroenergetycznego. Opisana została krótko specyfika pozyskiwania biogazu, oraz scharakteryzowano pokrótce założenia funkcjonowania elektrowni jądrowych. Następnie pokazane zostały możliwości oraz zalety wynikające z połączenia tych dwóch systemów w jednym miejscu i czasie, zarówno pod kątem efektywności energetycznej, jak i regulacji Unii Europejskiej dotyczących emisji dwutlenku węgla. Jak również, zarysowana została koncepcja funkcjonowania nowatorskiej elektrowni bazującej na połączeniu energii nuklearnej z wykorzystaniem biometanu.

EN

Proposed nuclear – biogas (biomass) synergy is an option, for power industry, which include technical, economical issues in polish energy industry. Considering the innovative view on possibility to combine two different energy systems. Outwardly such unlike two systems, like nuclear power plants, and biogas installation, can be attractive alternative for the development of the Polish power industry. In article was described, the methodology of biogas producing, basis for the functioning of nuclear power plants. Author shows advantages of nuclear – biogas synergy, both for power efficiency and carbon dioxide reduction method. Finally was described a few necessary aspects of functioning this new synergy system.

19

Study on power efficiency of vortex beam propagation through an optical system with phase optimization

Wu H., Sheng S., Huang Z., Wang H., Zhao S., Xu X., Sun Z., Xiao R.

Optica Applicata

|

2012

|

Vol. 42, nr 3

597-611

EN

Beam blocked and truncated by the receiver causes serious power losses in beam uplink propagation in a relay mirror system. We propose a method to improve power efficiency of beam uplink propagation in the relay mirror system by using vortex source and phase optimization. A typical model of beam uplink propagation in the relay mirror system is established. With this model, the principle of the method is theoretically analyzed, and power efficiencies of beam uplink propagation under different conditions are calculated. The calculation results show that power efficiency of beam uplink propagation can be improved from 86.44% to 97.86% by using vortex source and phase optimization. A reduced-scale experiment of beam uplink propagation in the relay mirror system under the "closed-loop" mode is performed, and the experimental results show that power efficiency can be improved from 71.89% to 91.59% by using the vortex source and phase optimization.

20

The cascade exchanger and new principles of the organization of working process of the sag-turbine engine

Klyus O., Krajniuk A.

Journal of Polish CIMAC

|

2012

|

Vol. 7, no 1

87-97

EN

Main trends of perfection of gas-turbine engines (GTE) by application of principles of the cascade pressure exchange (CPE) for air compression in the working cycle of gas-turbine plant have been analyzed. The results of computational investigation of four variants of the GTE working process organization on the basis of the two-staged compression assembly with intermediate cooling and heating of air-gas medium have been adduced. Possibility and reserve of raise of power efficiency of GTE with the CPE at the expense of increase in the maximum temperature of the cycle and recuperation of the residual heat of compressing gases have been shown.