Littérature scientifique sur le sujet « Source driver »

The authors propose a method to better domicile truck drivers in a relay-point highway transportation network to obtain better solutions for the truck driver domiciling and sourcing problem. The authors exploit characteristics of the truckload driver routing problem over a transportation network and introduce a new approach to domicile, source, and route truck drivers while more inclusively considering performance and cost measures related to the driver, transportation carrier, and customer. Driver domicile and relay-point locations are exploited to balance driver pay and recruiting costs and driving time. A mixed integer quadratic program will determine where driver domiciles are located to base drivers, source drivers, route drivers, etc. while considering key costs related to transporting truckload freight over long distances. A method to improve driver domicile locations is introduced to enhance driving jobs and driver sourcing, but not at the expense of the transportation carrier and customer. A numerical experiment will be conducted.

Quantum key distribution (QKD) has rapidly developed recently. The repetition frequency of the QKD system increases from tens or hundreds of MHz to GHz. A laser diode (LD) operating in gain-switched mode is widely used as a weak coherent light source in a QKD system. We present an LD driver circuit fabricated in 0.18 μm SiGe heterojunction bipolar transistor bipolar complementary metal oxide semiconductor technology. The circuit can operate at frequencies up to 2.5 GHz, satisfying the requirements of high-speed laser drives in practical QKD systems. The output current of the driver circuit can reach 100 mA when driving an LD whose input equivalent resistance is ∼21 Ω. The extinction ratio of the 1550-nm distributed feedback LD light source driven by our driver circuit reaches 23 dB at the operating frequency of 2.5 GHz, meeting the requirements of QKD systems. This circuit will be used in miniaturized QKD systems.

There is little research on the degrees of drivers’ short-term behaviours regarding driving safety. To solve this problem, this paper investigated the concept of driving proneness and evaluated the propensities of different drivers to engage in different operations for the following scenarios of urban traffic. From the real driving data of sixteen drivers on a city road, car-following data fragments were extracted and six key parameters were obtained: throttle percentage, change rate of throttle percentage, brake pressure, change rate of brake pressure, absolute value of steering angle and absolute value of steering angle speed. Symbolic Aggregate Approximation was used to reduce the dimensionality of the parameters. The input of the Hidden Markov Model-Viterbi was obtained by the use of statistical methods. The output of the model is the probability of the three proneness states of introversion, neutrality and extroversion, from which the proneness value of each driver was calculated. The weighted proneness value of each driver was obtained by the use of the entropy weight method to assign weights to each parameter. The operating characteristics of the drivers were also analysed and described. The method presented in this paper can provide accurate and real-time warning in network-driven environments.

Driver identification is very important to realizing customized service for drivers and road traffic safety for electric vehicles and has become a research hotspot in the field of modern automobile development and intelligent transportation. This paper presents a comprehensive review of driver identification methods. The basic process of driver identification task is proposed as four steps, the advantages and disadvantages of different data sources for driver identification are analyzed, driver identification models are divided into three categories, and the characteristics and research progress of driver identification models are summarized, which can provide a reference for further research on driver identification. It is concluded that on-board sensor data in the natural driving state is objective and accurate and could be the main data source for driver identification. Emerging technologies such as big data, artificial intelligence, and the internet of things have contributed to building a deep learning hybrid model with high accuracy and robustness and representing an important gradual development trend of driver identification methods. Developing a driver identification method with high accuracy, real-time performance, and robustness is an important development goal in the future.

An ICF plant is designed to use nuclear-driven flashlamp-pumped solid-state lasers as fusion drivers. It is proposed to use a separated fission reactor with aerosol fuel to drive alkali metal excimer flashlamps as the pumping source for solid-state lasers. The first observation of nuclear-excited sodium excimer emission at 436 nm in a TRIGA reactor with 815 Torr of He-3 and 60 Torr of sodium vapor (at T = 924 K) is reported. The experiment demonstrates the feasibility of a nuclear-driven alkali metal excimer lamp. The compatibility of alkali metal excimers with different laser crystals is evaluated for driver efficiency. High overall laser efficiency ensures large fractional output power extraction from nuclear fusion by this plant. The suitability of laser crystals for the ICF plant is also presented.

Abstract The current-generated magnetic filter is widely used in negative ion sources to bring down electron temperature and optimize source operation. The effect of the current-generated magnetic filter on plasma generation and transport is important. The axial distribution of cesium-free plasma parameters under different magnetic filter configurations was measured by a movable Langmuir probe at HUST negative ion source. Abnormal changes of plasma parameters are discovered at the driver exit. When the magnetic filter field penetrates into the driver, plasma density inside the driver increase, and the high-density high-temperature region of plasma expands outside of the driver. And the radiofrequency power coupling is also influenced by the magnetic filter. These experimental phenomena indicate that a new magnetic filter configuration is required to optimize source operation.

Abstract The current-generated magnetic filter is widely used in negative ion sources to bring down electron temperature and optimize source operation. The effect of the current-generated magnetic filter on plasma generation and transport is important. The axial distribution of cesium-free plasma parameters under different magnetic filter configurations was measured by a movable Langmuir probe at HUST negative ion source. Abnormal changes of plasma parameters are discovered at the driver exit. When the magnetic filter field penetrates into the driver, plasma density inside the driver increase, and the high-density high-temperature region of plasma expands outside of the driver. And the radiofrequency power coupling is also influenced by the magnetic filter. These experimental phenomena indicate that a new magnetic filter configuration is required to optimize source operation.

High switching-speed Silicon Carbide Metal-Oxide-Semiconductor Field-Effect Transistor (SiC MOSFET) has serious crosstalk issues. During the turn-ON transition and turn-OFF transition of the active switch in a phase-leg configuration, the voltage drops across the common-source inductor and the displacement current of the gate-drain capacitor of the OFF-state switch induce a spurious pulse on its gate-source voltage. This paper proposes a new gate driver using two Bipolar Junction Transistors (BJTs) and one diode to connect the gate terminal of SiC MOSFET and the negative driver voltage, which provides a low impedance path to bypass the displacement current of the gate-drain capacitor when crosstalk issues occur. The simulation results prove the proposed driver is valid on suppressing the crosstalk issue. The comparisons between the prior drivers and the proposed driver show the superiority of the proposed driver. Finally, the proposed gate driver is successfully implemented and experimentally verified on a 1.1 kW synchronous buck prototype.

The master oscillator power amplifier (MOPA) pulsed laser, one of the popular topologies for high-power fiber laser systems, is widely applied in industrial machining laser systems. In MOPA, the low-power pulsed laser, stimulated from a seed laser diode, is amplified by the high- power optical energy from pump laser diodes via the gain fiber. Generally, the high-power pump laser diodes are driven by lossy linear current drivers. The switched mode current drivers boost the driver efficiency but suffer from pulse energy consistency due to the current switching ripple. In this paper, a laser driver system that varies the switching frequency of current source to synchronize with pulsed laser repetition rate is analyzed and implemented. Experimental results are demonstrated using a 20 W pulsed fiber laser system.

L’aéronautique tend à hybrider la propulsion et à électrifier de plus en plus de fonctions. Ceci entraîne une augmentation de la tension du réseau de bord HVDC afin de répondre à ces nouvelles contraintes sur les réseaux et systèmes électroniques. Pour atteindre ces objectifs, les nouveaux composants à semi-conducteurs de puissance SiC en calibre 3.3kV semblent être une alternative pro- metteuse à la filière Silicium IGBT. Cependant, leur faible maturité par rapport à la technologie Si est le principal frein à leur implémentation dans les réseaux de bords. Les travaux de recherche s’inscrivent dans le projet RA- PID AM-PM. L’objectif du projet est de concevoir un module de puissance bras d’onduleur 3,3kV@500A en technologie SiC en apportant une rupture technologique sur le packaging de puissance et son monitoring. Les travaux de recherche concernent le développement d’un circuit de commande intelligent permettant de fiabiliser le module de puissance et d’assurer des commutations sécurisées du semiconducteur. A partir des études sur la fiabilité des compo- sants SiC, deux indicateurs de vieillissement ont été identifiés, la résistance à l’état passant du module et le courant de fuite de grille du composant semiconducteur. Des circuits de surveillance embarqués de ces indicateurs ont été proposés et une nouvelle topologie de com- mande des semiconducteurs, le source driver, est proposée afin de rendre ces circuits compatibles. Pour finir, un démonstrateur spécialement conçu pour le module AM-PM est testé sur module SiC
Aeronautics tend to hybridize propulsion and electrify more and more functions on board. This leads to an increase in the voltage of the onboard network in order to meet these new constraints from electronic systems. To achieve these objectives, the new 3.3kV-rating SiC power semiconductor components seem to be a promising alternative to the Silicon IGBT sector. However, SiC technology’s low level of maturity compared to Si technol- ogy is the main obstacle to its implementation. The research work is part of the AM-PM RAPID project. The project objective is to design a 3.3kV@500A inverter arm power module in SiC technology by providing a technological break- through in power packaging and its monitoring. The research work focuses on the development of the gate driver and its intelligent functions to make the power module more reliable and to ensure secure switching of the semiconductor. From studies on the SiC component’s reliability, two aging indicators have been identified, the on-state resistance of the module and the gate leakage current of the semiconductor compo- nent. On-board monitoring circuits for these in- dicators have been proposed and a new semi- conductor control topology, the source driver, is proposed in order to make these circuits com- patible. Finally, a demonstrator specially de- signed for the AM-PM module is tested on a SiC module

The purpose of this thesis is to develop a low-cost, high power laser diode/fiber illumination system and to design the driver electronics of the spatial light modulator (SLM) for holographic, three dimensional (3D) imaging. A miniaturized laser diode/fiber/polarizing illumination system capable of 15mW of output at a wavelength of 690nm is designed, fabricated, and tested. The size limitations of various commercially available SLM drivers are described and the design to overcome them is suggested. The design describes in detail the timing considerations of the hardware interface and the psuedocode of the software interface between the host computer and the SLM. Experiments carried out to study the spatial uniformity of the SLM and the distortion due to the beam splitter on the structured output from the LIM are explained.
Master of Science

The aim of this thesis is to design, produce and verify the operation of two different LED drivers for automotive industry, which controls the ultra-bright white LEDs. At the beginning of a brief introduction explaining the principle of operation of LEDs. Furthermore theory describes the functions of all three basic drivers involved as buck, boost and buck-boost. Based on the requirements are selected ICs suitable for this implementation, theoretically described their block diagrams including the individual diagrams and eventually these samples are made, revived and measured their parameters.

Laser Diodes (LDs) are semiconductor coherent lightening devices which are widely used in many fields such as defence, industry, medical and optical communications. They have advantageous characteristics such as having higher electrical-to-optical and optical-to-optical conversion efficiencies from pump source to useful output power when compared to flash lamps, which makes them the best devices to be used in range finding applications. Optical output power of lasers depends on current through LDs. Therefore, there is a relationship between operating life and work performance of LDs and performance of drive power supply. Even, weak drive current, small fluctuations of drive current can result in much greater fluctuations of optical output power and device parameters which will reduce reliability of LDs. In this thesis, a hardware for a fast and high power pulsed LD driver is designed for laser range finder and is based on linear current source topology. The driver is capable of providing pulses up to 120A with 250&mu
s pulse width and frequencies ranging from 20Hz to 40Hz. It provides current pulses for two LD arrays controlled with a proportional-integral (PI) controller and protect LDs against overcurrents and overvoltages. The proposed current control in the thesis reduces current regulation to less than 1% and diminishes overshoots and undershoots to a value less than 1% of steady-state value, which improves safe operation of LDs. Moreover, protection functions proposed in the thesis are able to detect any failure in driver and interrupt LD firing immediately, which guarantees safe operation of LDs.

The two projects of the ITER Neutral Beam Test Facility (NBTF) [1] in Padova are MITICA, the full scale prototype of the heating Neutral Beam Injector (NBI) and SPIDER, the full-size negative ion source of the NBI. Both include a Radio Frequency (RF) Ion Source where plasma is produced by the inductive coupling with coils wound around vacuum chambers called drivers. Each coil is fed at 1 MHz up to a power of 100 kW, which corresponds to a voltage of about 12 kV rms, with nominal plasma parameters. The ion source design derives from the R&D carried out at the Max-Planck-Institut für Plasmaphysik (IPP) during the past years [2] [3], with additional improvements to achieve the desired performance in long duration pulses (up to 1 h) on a full ITER-size device, in a vacuum environment and with optimized beamlet optics [4] [5] [6] [7]. Among the various issues connected to the fulfillment of the requirements for ITER, special attention should be paid to those related to the voltage hold off in vacuum of the beam source components; not only for the acceleration grids subjected to very high dc voltage but also for the RF circuits of the ion source and in particular the RF drivers. Some concern in this regard has arisen since several years ago and in fact, also in IPP, the last two test facilities RADI and ELISE have been realized in such a way the areas containing the drivers that can be put under vacuum (lower than 10 4 mbar [8]) to better simulate the ITER operating condition [9] [10]. For the ITER heating NBI the concern is deeper, since the rear side of the ion source, where the drivers are located, is not directly pumped and the pressure at the moment is only estimated by means of simulation. The voltage hold off of the driver coils is essential to operate the ion source at full power and thus to reach the full performance. The topic of the PhD activity belongs to the framework of the RF R&D task of the NBTF workprogramme, and was focused on the development of a simple, accessible and flexible device called "High Voltage Radio Frequency Test Facility" (HVRFTF) to characterize the dielectric strength in vacuum of the RF drivers of SPIDER and MITICA ion sources and to effectively address the issues related to their voltage hold off when subjected to radiofrequency E-fields at low pressure. The experimental arrangement worked out to reproduce the desired operating conditions consists in a vacuum vessel capable to host different types of driver mock-ups, called Devices Under Test (DUT) in the thesis, a gas injection and pumping system to supply the desired gas species up to the test pressure and a RF circuit designed to produce the high voltage. The HVRFTF allows the variation of the quantities which influence the voltage hold off, such as the pressure, geometry and materials of the DUTs, in order to perform parametric analyses. The idea behind this flexibility is not only to execute tests relevant for the verification of the driver insulation design, but also to quantify operative margins and to identify possible improvements or hints for the design of new drivers. Part of the thesis work was the identification of the requirements of the HVRFTF, consisting in analyses carried out to identify the driver operating conditions relevant to the voltage hold off (geometry, materials and pressure). I estimated the voltage applied to the RF coil of the drivers at full power, and the related E-field, with the identification of the most stressed area. I conceived several driver mockups to be tested within the HVRFTF: the best configuration worked out for the scope is based on a couple of electrodes (one plane and one spherical) with a dielectric material in between. However, the studies highlighted that a single sphere diameter is not sufficiently accurate to cover the entire gap range of interest; in particular the sphere diameter has to be increased as far as the gap increases. Nevertheless, three of these DUTs allow reproducing the desired E-field trend. I decided to test at first a planar circular electrode pair with Rogowski profile, even if it is not suitable as driver mock-up, since it is a test configuration widely treated in the literature and it generates the most reproducible experimental regime, thus allowing a validation of the basic test arrangement. As far as the RF high voltage generation is concerned, the feasibility study led me to work out a resonant circuit matched through a reversed L-type network, supplied by a low voltage amplifier. As a first design approach, the load of the circuit to be matched to the low voltage amplifier output impedance could be the DUT, but the practical implementation of this concept in the design of the RF circuit is complex due to the variation of the DUT impedance during the test campaign and the effect of stray impedances of circuit components. From the electrical point of view, the DUT represents a capacitance with an equivalent series resistance; both depend on the geometry of the electrode pair, on the gap between the two electrodes, and on the properties of the dielectric material in between. The selected approach was to design a suitable inductor to be connected in parallel to the DUT and to use their equivalent impedance as the load impedance to be matched. With this method and once verified that the real part of the load impedance is lower than the real part of the amplifier output impedance, the matching network can be composed by capacitors only, that were designed to assure the matching condition at the nominal frequency. Variable capacitors can be adopted in order to modify the resonance frequency and maintain the matching condition in the whole frequency range of interest. Another important phase of my design work was the development of the electrical model of the components to be used, in order to verify and quantify the real power requirements as a function of the voltage to be reached with the HVRFTF. The realization of the HVRFTF was completed in 2016 with a first RF circuit composed of fixed capacitors and supplied by a RF amplifier rated for a limited power, both already available at Consorzio RFX. The test campaigns on a stainless steel planar circular electrode pair proved the correct operation of the overall plant and allowed obtaining the first experimental results, including in particular the achievement of a voltage up to 10 kV rms. Moreover the tests gave the opportunity to improve the knowledge in this field, discover unexpected issues relevant to specific operating conditions and investigate on possible solutions. Another important fallout of the tests was the validation of the models developed during the design phase, essential for the continuation of the R&D work. The thesis is organized as follows: - Chapter 1 presents the thesis background: starting from the identification of the need for sustainable energy sources, nuclear fusion is identified as a suitable contributor. ITER is the next step toward nuclear fusion and PRIMA, the ITER neutral beam test facility is one of the main supporting R&D projects, with its two experiments SPIDER and MITICA. The experiments are introduced with a brief description. - Chapter 2 enters more in details in one of the components of SPIDER and MITICA beam sources which is considered critical as far as the voltage holding is concerned: the driver. Its operating conditions are described in this chapter. - Chapter 3 presents the High Voltage Radio Frequency Test Facility (HVRFTF), a small, accessible and flexible testbed to experimentally characterize the dielectric strength in vacuum of the driver. - Chapter 4 reports on the analyses carried out for the definition of the devices to be tested within the HVTFTF, relevant mockups of the drivers. - Chapter 5 reports on the studies and the design of the circuit used in the HVRFTF for the generation of high voltage at radiofrequency. - Chapter 6 presents the experimental results obtained so far with the HVRFTF. - Conclusions.
La stazione sperimentale Neutral Beam Test Facility (NBTF) dell'esperimento ITER [1], in costruzione a Padova presso il Consorzio RFX, ospita due esperimenti: MITICA, il prototipo in scala 1:1 del sistema di iniezione di particelle neutre per il riscaldamento del plasma in ITER (NBI) e SPIDER, il prototipo della sorgente ionica impiegata dal NBI. Entrambi i progetti impiegano 8 "driver" a radiofrequenza (RF), ovvero sorgenti di plasma, per la generazione di ioni; ciascun driver è costituto da una camera da vuoto cilindrica su cui è avvolta una bobina che si accoppia induttivamente con il plasma. Ogni bobina è alimentata da un'onda sinusoidale di tensione a 1 MHz, con una potenza fino a 100 kW alla quale corrisponde, con i parametri nominali di plasma, un valore efficace di tensione tra i terminali di circa 12 kV rms. La soluzione progettuale della sorgente ionica deriva dall'attività di ricerca e sviluppo effettuata al Max-Planck-Institut für Plasmaphysik (IPP) negli scorsi anni [2] [3], ulteriormente studiata e sviluppata per raggiungere le prestazioni desiderate per ITER ed in particolare quelle legate al miglioramento dell'ottica del fascio e al funzionamento in vuoto con impulsi di durata prolungata fino ad un'ora [4] [5] [6] [7]. Tra le varie problematiche legate al soddisfacimento dei requisiti per ITER, particolare attenzione è rivolta alla tenuta della tensione in vuoto dei componenti e dei circuiti dell'iniettore, non solo per le griglie di accelerazione che sono soggette a tensioni dc fino a 1 MV, ma anche per i circuiti RF della sorgente e in particolare dei driver. La consapevolezza della criticità di questo aspetto è maturata negli ultimi anni e di conseguenza è cresciuta l'attenzione al problema: anche i più recenti esperimenti presso IPP (RADI ed ELISE) prevedono la possibilità di mettere in vuoto (con pressione inferiore a 10-4 mbar [8]) il volume contenente i driver, per poter simulare meglio le condizioni operative di ITER [9] [10]. Per l'iniettore di neutri di ITER la preoccupazione è anche maggiore, poiché non vi potrà essere controllo diretto della pressione nella regione dei driver; al momento essa è stimata per mezzo di simulazioni numeriche. La tenuta di tensione della bobina dei driver è essenziale al fine di operare la sorgente alla piena potenza, requisito per il raggiungimento delle piene prestazioni dell'iniettore. L'argomento del dottorato ricade nell'ambito della task "RF R&D" del programma di lavoro della NBTF ed è focalizzato allo sviluppo di un esperimento semplice, accessibile e flessibile chiamato "High Voltage RadioFrequency Test Facility" (HVRFTF), indirizzato allo studio delle problematiche legate alla tenuta di tensione in vuoto dei driver RF delle sorgenti di SPIDER e MITICA. Il setup sperimentale di HVRFTF consente di ricreare le condizioni operative delle bobine dei driver e consiste in una camera da vuoto capace di ospitare diversi dispositivi in prova, chiamati Device Under Test (DUT) nella tesi, un sistema di pompaggio e immissione gas in grado di regolare la pressione e la specie di gas all'interno della camera e di un circuito a radiofrequenza in grado di produrre l'alta tensione. HVRFTF permette la variazione delle grandezze fisiche che influenzano la tenuta di tensione, come ad esempio la pressione, la geometria e i materiali dei dispositivi in prova, al fine di poter effettuare analisi parametriche. Questa flessibilità permette non solo di verificare il progetto dell'isolamento dei driver, ma anche di quantificarne i margini operativi e di identificare possibili miglioramenti o spunti per il progetto elettrico di nuovi driver. Parte del lavoro di tesi è stato dedicato alla definizione dei requisiti di HVRFTF, a partire dallo studio della sorgente e delle condizioni operative dei driver che ne influenzano la tenuta di tensione. Ho stimato la tensione applicata alla bobina RF dei driver a piena potenza e ricavato la relativa mappa di campo elettrico, che mi ha consentito di identificare la regione maggiormente stressata. In seguito ho concepito diversi possibili modelli di driver da testare all'interno di HVRFTF: il migliore è basato su una coppia di elettrodi (un piano e una sfera) tra i quali è interposto un disco di materiale dielettrico. Tre sfere di diametro direttamente proporzionale al gap sono necessarie per riprodurre l'andamento del campo elettrico nell'intero intervallo di variazione del gap. Per le prime prove con HVRFTF ho deciso di testare degli elettrodi piani circolari con profilo di Rogowski, anche se non rappresentano un buon modello del driver, al fine di validare il setup sperimentale. L'uso di questo tipo di elettrodi è infatti ampiamente diffuso e documentato in letteratura, perché essi sono in grado di generare condizioni sperimentali riproducibili. Per la generazione di alta tensione a radiofrequenza, tra possibili soluzioni ho adottato un circuito risonante adattato all'impedenza di uscita dell'amplificatore che lo alimenta, attraverso una rete a L rovesciato. In prima istanza, il carico da adattare potrebbe essere l'impedenza del DUT, che dal punto di vista elettrico risulta essere una capacità in serie ad una resistenza, entrambe dipendenti dalla geometria degli elettrodi, dalla loro distanza (gap) e dalle proprietà del materiale dielettrico interposto tra loro. Tuttavia l'implementazione pratica di quest'approccio è complessa: l'impedenza del DUT durante la campagna sperimentale è variabile; inoltre i componenti del circuito di adattamento (almeno uno dei quali dovrebbe essere un induttore), introducono impedenze parassite non note, a loro volta da compensare. Una soluzione ragionevole che ho infine elaborato consiste nel collegare in parallelo al DUT un induttore di caratteristiche opportune e di utilizzare l'impedenza equivalente come carico da adattare. Con questo approccio, una volta dimensionati i componenti in modo tale che la parte reale dell'impedenza di carico sia minore della parte reale dell'impedenza di uscita dell'amplificatore, la rete di adattamento a L rovesciato risulta composta da soli condensatori, le cui capacità si ricavano imponendo il vincolo di adattamento di impedenza e la frequenza di risonanza. L'utilizzo di condensatori aventi capacità regolabile permette infine di modificare la frequenza di risonanza in modo da poter operare in tutto l'intervallo di frequenze di interesse. Per il progetto del circuito RF ho sviluppato modelli elettrici dettagliati per ogni componente impiegato, al fine di verificare e quantificare i requisiti di potenza attiva in funzione della tensione da raggiungere con HVRFTF. La realizzazione preliminare di HVRFTF è stata completata nel 2016 con un circuito a radiofrequenza composto da condensatori aventi capacità fissa, alimentato da un amplificatore RF di potenza limitata; sia i condensatori che l'amplificatore erano già disponibili al Consorzio RFX. La campagna di prove sperimentali con la coppia di elettrodi piani in acciaio ha dimostrato il corretto funzionamento dell'impianto sperimentale con il raggiungimento della tensione di 10 kV, ha consentito di ottenere i primi risultati sperimentali e di validare i modelli sviluppati durante la fase di progetto. Il lavoro presentato in questa tesi è così organizzato: - Capitolo 1: si presenta il contesto tematico all'interno del quale è stata sviluppata la tesi; a partire dal problema energetico, una possibile soluzione è un mix di fonti sostenibili tra cui la fusione nucleare. Si presentano in seguito ITER, il prossimo passo verso la fusione e "ITER Neutral Beam Test Facility", uno dei principali progetti a supporto di ITER con i suoi due esperimenti: SPIDER e MITICA. - Capitolo 2: si descrive in dettaglio uno dei componenti delle sorgenti ioniche di SPIDER e MITICA, ritenuto critico dal punto di vista della tenuta di tensione: il driver. Si presentano le analisi eseguite per derivare le sue condizioni operative. - Capitolo 3: si presenta l'esperimento "High Voltage Radio Frequency Test Facility" (HVRFTF), un piccolo impianto per la caratterizzazione sperimentale della rigidità dielettrica in vuoto dei driver. - Capitolo 4: si presentano le analisi effettuate per la definizione dei dispositivi da testare con HVRFTF, con l'obiettivo che essi possano riprodurre condizioni operative simili a quelle del driver per lo studio della problematica di interesse . - Capitolo 5: si riportano gli studi per la generazione di alta tensione a radiofrequenza e il progetto del circuito risonante adottato per HVRFTF. - Capitolo 6: si presentano i risultati ottenuti con HVRFTF. - Conclusioni.

Згідно теми дипломної роботи, проаналізовано актуальні проблеми експлуатації освітлювальних систем з LED-приладами. Проведено дослідження методів регулювання характеристик LED-приладів. Здійснено розрахунок електричних навантажень комплексу устаткування та освітлювальної установки. Здійснено проектування освітлювальної установки та аварійного освітлення. Запропоновано методи підвищення надійності функціонування освітлювальних систем з LED-приладами. Обгрунтовано ефективність та економічність методики переходу на LED-джерела світла.
According to the topic of diploma project, actual problems of operation of lighting systems with LED devices are analyzed. The methods of regulation of the characteristics of LED devices are investigated. The electrical loads of the equipment complex and the lighting system are calculated. The complex of lighting system and emergency lighting is designed. Methods of increasing the reliability of the operation of lighting systems with LED devices are proposed. The efficiency and cost-effectiveness of the method of switching to LED light sources are substantiated.
РЕФЕРАТ ... 3 ЗМІСТ.. 4 ВСТУП ... 6 І.АНАЛІТИЧНА ЧАСТИНА 1.1 Загальні відомості про напівпровідникові світлові прилади 1.1.1 Принцип роботи, технологія виробництва та переваги світлодіоднихсвітлових приладів. Основні параметри LED-ламп ... 9 1.1.2 Типи світлодіодів. Ступені захисту світлових приладів .... 16 1.1.3 Блоки живлення світлодіодних світильників .... 20 1.2 Актуальні проблеми використання напівпровідникових СП в промислових освітлювальних установках. Шляхи їх вирішення ... 22 1.3.1 Застосування NTC-термісторів обмеження струму ... 28 1.3.2 Застоcування автоматичних вимикачів ... 29 1.3.3 Перетворювальні плати ... 34 1.3.4 Світлодіодні драйвери керування. Протокол DALI. Драйвери плавного включення... 38 II. НАУКОВО-ДОСЛІДНА ЧАСТИНА 2.1 Дослідження та вибір системи керування ОУ. ... 47 III. ТЕХНОЛОГІЧНА ЧАСТИНА 3.1 Аналіз об’єктів. Особливості роботи цехів. ... 61 IV. ПРОЕКТНО-КОНСТРУКТОРСЬКА ЧАСТИНА 4.1 Визначення розрахункових навантажень ... 66 4.2 Розрахунок потужності розподільчих пунктів ... 69 4.3 Розрахунок потужності окремих електроприймачів, які не входять в РП.... 71 4.4 Визначення центру електричних навантажень .... 74 4.5 Вибір світлових приладів ... 78 4.6 Нормоване освітлення. .... 84 5 4.7 Вибір системи освітлення. Розрахунок кількості світильниківв середовищі програми RELUX. ... 85 4.8 Аварійне освітлення ... 89 V. СПЕЦІАЛЬНА ЧАСТИНА 5.1 Аналіз переваг та ефективності програми світлотехнічного розрахунку та 3D-моделювання RELUX .... 94 5.2 Аналіз переваг та ефективності програми моделювання КОМПАС-3D .... 98 VІ. ОРГАНІЗАЦІЙНО-ЕКОНОМІЧНА ЧАСТИНА 6.1 Фізичний і моральний знос. Амортизація, модернізація і ремонт основних фондів. ... 101 6.2 Оцінка економічної ефективності переходу з ЛР на LED-джерела світла. Розрахунок затрат на реалізацію проекту .... 105 VIІ. ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ 7.1 Вплив умов освітленості на організм людини .... 109 7.2 Електрозахисні засоби та запобіжні пристосування .... 111 7.3 Протипожежні вимоги до улаштування та експлуатації електроустановок... 112 7.4 Плануваннязаходів цивільного захисту на підприємствах електротехнічної та світлотехнічної галузі у випадку надзвичайних ситуацій... 115 7.5 Захист персоналу об’єктів енергетикивід впливу іонізуючого випромінювання .... 118 VIIІ. ЕКОЛОГІЯ 8.1 Сучасні тенденції електроспоживання .... 121 8.2 Аналіз сучасних джерел світла та ступеня їх екологічності ... 123 ВИСНОВКИ ...127 ПЕРЕЛІК ПОСИЛАНЬ ... 128 ДОДАТКИ ... 132

Goal of this semestral thesis is to design power converter which is to be used for measurement. The converter consists of two forward converters in push-pull topology. The converter is to behave as a constant current source with maximum open-circuit voltage of 1000V. Maximum current is 5A. The current range is split into three sub-ranges, to meet the strict requirements on ripple current. The range of currents is 0-5A. The operating frequency of converter is 34KHz. The converter will be charged using two portable electric generators with output voltage 230V.

This diploma thesis deals with the design and construction of a three-axis CNC machine primarily designed for PCB drilling and production of front panels for various electronic devices. All three axes are driven by stepper motors NEMA 23 which are connected to stepper motor drivers L6470. Processor STM32F407 is used to control the whole machine. The wiring is completed by a LCD display with touchscreen which is used to communicate with user. Data for drilling can be entering manually or via USB inerface. Part of this thesis is the selection of a suitable construction and components, assembling equipment, wiring design of electronic circuits and writing the code to control the machine. Finally, the parameters of the designed device have been measured.

AbstractLogit Model is an important method for empirical analysis of multi-source data. In order to explore the traffic safety mechanism, The Paper taked traffic behavior data as an example, researched personal characteristics of truck drivers, Analyzed the influence of the driver’s personal traits on traffic violations. Based on the binary logistics regression model, the analysis model of traffic violations was established. The results show that personality, driver’s license level, daily driving time, transportation route, vehicle ownership, and occupational disease are important factors that affect drivers’ violations. Further data analysis shows that truck drivers with bile personalities, driving for more than 12 h per day, no fixed transportation routes, and vehicles with loans have the highest probability of violations. The data analysis conclusion provides data basis for truck driver management and improving truck traffic safety.

Abstract Computers store numbers in two mutually incompatible ways: little-endian or big-endian. They differ in the order of bytes within representation of numbers. This ordering is called endianness. When two computer systems, programs or devices communicate, they must agree on which endianness to use, in order to avoid misinterpretation of numeric data values. We present Endicheck, a dynamic analysis tool for detecting endianness bugs, which is based on the popular Valgrind framework. It helps developers to find those code locations in their program where they forgot to swap bytes properly. Endicheck requires less source code annotations than existing tools, such as Sparse used by Linux kernel developers, and it can also detect potential bugs that would only manifest if the given program was run on computer with an opposite endianness. Our approach has been evaluated and validated on the Radeon SI Linux OpenGL driver, which is known to contain endianness-related bugs, and on several open-source programs. Results of experiments show that Endicheck can successfully identify many endianness-related bugs and provide useful diagnostic messages together with the source code locations of respective bugs.

AbstractSemiarid South African ecosystems are managed for livestock production with different practices and intensities. Many studies have found grazing to be an important driver of vegetation change; however, its impacts on carbon fluxes remain poorly studied. Unsustainable management over the past 200 years has led to an increase of degraded areas and a reduction in species diversity, but destocking trends in the past three decades may be facilitating a recovery of net primary productivity and vegetation cover in some areas. This chapter provides a brief historical overview on livestock management practices and their likely impact on carbon exchange in the Nama-Karoo Biome. We present a case study based on five years of eddy covariance measurements, in which effects of past and current livestock grazing on CO2 exchange were studied. Two sites with different livestock management but similar climatic conditions formed the basis for this preliminary effort to improve the understanding of carbon exchange and its drivers under contrasting management regimes. The case study revealed that net CO2 exchange is near-neutral over an annual scale, with precipitation distribution emerging as the main controlling factor of subannual variance. Although CO2 release at the lenient grazing site was slightly higher than at the experimental grazing site, longer time series are likely needed in such variable ecosystems to make a pronouncement regarding long-term net fluxes. Given their vast extent, livestock rangelands may have an important effect on regional carbon balance.

AbstractAs software architecture is a main driver for the software quality, source code is often accompanied by software architecture specifications. When the implementation is changed, the architecture specification is often not updated along with the code, which introduces inconsistencies between these artifacts. Such inconsistencies imply a risk of misunderstandings and errors during the development, maintenance, and evolution, causing serious degradation over the lifetime of the system. In this chapter we present the Explicitly Integrated Architecture approach and its tool Codeling, which remove the necessity for a separate representation of software architecture by integrating software architecture information with the program code. By using our approach, the specification can be extracted from the source code and changes in the specification can be propagated to the code. The integration of architecture information with the code leaves no room for inconsistencies between the artifacts and creates links between artifacts. We evaluate the approach and tool in a use case with real software in development and with a benchmark software, accompanied by a performance evaluation.

We assess the quantitative relevance of expectations-driven sovereign debt crises, focusing on the Southern European crisis of the early 2010s and the Argentine default of 2001. The source of multiplicity is the one in Calvo (1988). Key for multiplicity is an output process featuring long periods of either high growth or stagnation that we estimate using data for those countries. We find that expectations-driven debt crises are quantitatively relevant but state dependent, as they only occur during stagnations. Expectations are a major driver explaining default rates and credit spread differences between Spain and Argentina.

The method of heating water by means of a water jacket installed in the firebox of a solid-fuel burner, connected by pipes to a hot-water cylinder (HWC), was once commonplace in New Zealand, but has become less so in recent years. These systems, known as wetbacks, are covered by Building Code Clause G12, but considerable confusion has been caused by conflicting rules specified in the two main compliance documents, G12/AS1 and AS/NZS 3500.4 (hot water). In both compliance documents, wetback systems are defined as ‘uncontrolled heat sources’ with specific rules and limitations that stipulate how they are to be installed, and to keep them safe. However, other than common safety rules, each has entirely different ‘mandatory’ installation rules that affect the efficiency of the systems. They couldn’t both be right, but they could both be wrong. This is further confused by another standard, NZS 4603:1985, being mentioned in G12 as ‘another acceptable solution’ and differing from and contradicting both of the above. This standard is often quoted by manufacturers in their instructions. One driver of this research, from a regulatory view, was to determine which of the two main compliance documents was correct, if either.

The 6 th Assessment Report cycle of the Intergovernmental Panel on Climate Change (AR6) comes at a precipitous moment in history. Human influence has warmed the planet, and widespread and rapid impacts are occurring to natural and human systems in all regions of the world. In response, immediate action is needed if there is to be any hope of limiting global warming to 1.5°C or well below 2°C below pre-industrial levels, as well as preparing for and adapting to current and future risks. The transformations needed in response to climate change will require decisive action in cities and urban areas. Cities and urban areas are a major source and driver of emissions; they are also crucial sites for system transitions in the near term and transformations over longer time frames