Kliknij ten link, aby zobaczyć inne rodzaje publikacji na ten temat: Modern power system.
Rozprawy doktorskie na temat „Modern power system”
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 50 najlepszych rozpraw doktorskich naukowych na temat „Modern power system”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj rozprawy doktorskie z różnych dziedzin i twórz odpowiednie bibliografie.
1
Hernandez, Michael. "Applications of modern control in power electronics". Paris 11, 2010. http://www.theses.fr/2010PA112161.
Pełny tekst źródłaStreszczenie:
Dans la première partie, cette dissertation continue le cadre pour l'analyse et la conception (probablement des compensateurs de facteur) de puissance (PF) non linéaire pour les systèmes électriques fonctionnant dans des régimes nonsinusoïdaux (mais périodiques) avec les charges non linéaires. En particulier, dans la prétention standard que le générateur est une source de tension sans l'impédance, nous avons caractérisé toutes les charges non linéaires dont le pf est amélioré avec un compensateur non linéaire indiqué. Et ce cadre est employé pour étudier le problème de lacompensation passive de pf d'un redresseur commandé par pont classique. Est donné le fonctionnement "à l'avance de phase" du redresseur qu'on s'attend à ce que la compensation capacitive améliore le pf. Il est cependant moins évident que ceci puisse également être réalisé (dans quelques conditions appropriées) avec des inducteurs. Dans la deuxième partie, on a proposé la méthodologie d’A pour concevoir les contrôleurs (PI) proportionnel-intégraux linéaires utilisés des applications de convertisseur de puissance et en assurant la stabilité asymptotique. La technique s’est fondée sur le fait de base que si un système d’affinage peut être rendu passif avec une commande constante, alors il est stabilisable avec pi. Un état structural a été imposé alors au convertisseur de puissance pour satisfaire l’ancienne propriété avec un résultat passif produit comme combinaison linéaire des états. Cette condition est technique et n’a aucune interprétation physique claire. Ce résultat est prolongé dans trois directions : d’abord, la condition mentionnée ci-dessus est enlevée ; en second lieu, une plus grande classe des convertisseurs (avec des sources extérieures de commutation) est considérée ; troisièmement, la résistance de charge est assumée qu’on propose l’inconnu et un contrôleur adaptatif de pi (avec trois estimateurs différents). La méthodologie est appliquée au problème de la compensation de facteur de puissance d’un redresseur triphasé de source de tension, avec des résultats de simulation proposés. En outre, pi adaptatif stable est conçu pour la régulation de tension de rendement d’un convertisseur quadratique de poussée montrant l’exécution au moyen de résultat expérimental. Dans la troisième partie quelques contrôleurs basés sur le concept de la commande de charge pour un convertisseur utilisé dans une mise sous tension la correction de facteur sont montrés. Le convertisseur se compose par le raccordement intercalé de deux convertisseurs ou plus de poussée reliée à la grille à l’aide d’un redresseur de diode non commandé. La commande de charge représente une solution bon marché pour garantir la mise en commun courante entre les différents convertisseurs impliqués, et est normalement employée en combination avec d’autres contrôleurs. Les deux contrôleurs sont d’abord conçus pour garantir le facteur de puissance de près d’un avec la tension CC Réglée, à laquelle la commande de charge est ajoutée pour distribuer le courant égal parmi les convertisseurs. En conclusion, on présente une simplification avec l’exécution semblable qui élimine l’utilisation des sondes courantes, excepté les transformateurs de courant exigés pour mettre en application la commande de charge, des résultats expérimentaux accomplissent cette cloison. La quatrième partie, présente l’exécution et la programmation d’une méthode pour dépister le point de puissance maximum (MPP) dans des applications (PV) photovoltaïques. Ce point de fonctionnement est d’intérêt spécial pendant qu’on l’exige pour extraire la puissance maximum disponible à partir des rangées photovoltaïquesIn the first part, this dissertation continues with the framework for analysis and design of (possibly nonlinear) power factor (PF) compensators for electrical systems operating in non-sinusoidal (but periodic) regimes with nonlinear loads. In particular, under the standard assumption that the generator is a voltage source with no impedance, we characterized all nonlinear loads whose PF is improved with a given nonlinear compensator. And this framework is used to study the problem of passive PF compensation of a classical half-bridge controlled rectifier. Given the “phase advance” operation of the rectifier it is expected that capacitive compensation improves PF, it is however less obvious that this can also be achieved (under some suitable conditions) with inductors. In the second part, A methodology to design linear proportional-integral (PI) controllers used in power converter applications and ensuring asymptotic stability was proposed. The technique relied on the basic fact that if an affine system can be rendered passive with a constant control, then it is stabilizable with a PL A structural condition was imposed then on the power converter to satisfy the former property with a passive output generated as a linear combination of the states. This condition is technical and has no clear physical interpretation. This result is extended in three directions : first, the aforementioned condition is removed ; second, a larger class of converters (with switching external sources) is considered ; third, the load resistance is assumed unknown and an adaptive PI controller (with three different estimators) is proposed. The methodology is applied to the problem of power factor compensation of a 3-phase. Voltage source rectifier, with simulation results proposed. Also, a stable adaptive PI is designed for the output voltage regulation of a quadratic boost converter showing the performance by means of experimental result. In the third part some controllers based on the concept of charge control for a converter used in an application of power factor correction are shown. The converter is composed by the interleaved connection of two or more boost converters connected to the grid by means of a non controlled diode rectifier. Charge control represents a cheap solution to guarantee current sharing among the different converters involved, and is normally used in combination with other controllers. The two controllers are first designed to guarantee the power factor close to one with regulated DC voltage, to which charge control is added to distribute equal current among the converters. Finally, a simplification with similar performance is presented that eliminates the use of current sensors, except for the current transformers required to implement the charge control, experimental results complete this part. The fourth part presents the implementation and programming of a method to track the maximum power point (MPP) in photovoltaic (PV) applications. This operation point is of special interest as it is required to extract the maximum power available from the photovoltaic arrays
2
Dong, Zhao Yang. "Advanced methods for small signal stability analysis and control in modern power systems". Phd thesis, School of Electrical and Information Engineering, Graduate School of Engineering, 1998. http://hdl.handle.net/2123/6416.
Pełny tekst źródła
3
Hu, Boyang. "Design and Analysis of PV/Battery/EV in Modern Distribution Power System". Thesis, The University of Sydney, 2013. http://hdl.handle.net/2123/9896.
Pełny tekst źródłaStreszczenie:
In recent decades, power grids have been undergoing re-structuring gradually because of more and more renewable sources tied to grid. Two-way flows of electricity and information create an automated and intelligent electricity network.The broad aim of this thesis is to provide future utility providers and customers with new Smart-grid technologies to achieve a more intelligent, efficient, reliable and stable distribution power system. Research projects are based on the development of the new technologies of photovoltaics (PV), battery energy storage system (BESS), and electric vehicles (EV). Taking into account the abilities to both buck and boost the PV voltage, and designing the non-inverting characteristic for converter output polarity, this thesis proposes a new multiple inputs PV configuration that features effective accommodation of PV shading conditions and fast response to rapidly changing solar irradiations. A new interleaving technology is proposed for multiple inputs PV systems. It can effectively reduce the current ripples for parallel-connect, or voltage ripples for series-connect PV configurations, respectively. A new sizing method has been proposed for BESS. Conventional sizing methods simply assume the specific values of depth of discharge (DoD) and project lifetime years. However, different values of DoD can significantly affect the use of batteries. As well, a difference of one or two years in project lifetime may result in the need for an additional BESS replacement. A novel optimal scheduling method has been proposed for EV aggregators for both Grid to Vehicle (G2V) and Vehicle to Grid (V2G) applications. Unlike traditional scheduling methods, which only relate to G2V or V2G, the proposed bi-level optimization method simultaneously minimizes charging costs and gains reactive power support from EV chargers. The detailed investigation, design and verification results are presented in this thesis.
4
Alghamdi, Turki. "Interactions of Connected Electric Vehicles with Modern Power Grids in Smart Cities". Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42513.
Pełny tekst źródłaStreszczenie:
In a smart city, it is vital to provide a clean and green environment by curbing air pollution and greenhouse gas emissions (GHGs) from transportation. As a recent action from many governments aiming to minimize transportation’s pollution upon the climate, new plans have been announced to ban cars with gas engines throughout the world. Therefore, it is anticipated that the presence of electric vehicles (EVs) will grow very fast globally. Consequently, the necessity to establish electric vehicle supply equipment (EVSE) in the smart city through public charging stations is growing incrementally year by year. However, the EV charging process via EVSE which is primarily connected to the power grid will put high pressure upon the centralized power grid, especially during peak demand periods. Increasing the power production of power grid will increase the environmental impact. Therefore, it is fundamental for the smart city to be equipped with a modern power grid to cope with the traditional power grid’s drawbacks.
In this thesis, we conduct an in-depth analysis of the problem of EVs’ interaction with the modern power grid in a smart city to manage and control EV charging and discharging processes. We also present various approaches and mechanisms toward identifying and investigating these challenges and requirements to manage the power demand. We propose novel solutions, namely Decentralized-EVSE (D-EVSE), for EVs’ charging and discharging processes based on Renewable Energy Sources (RESs) and an energy storage system. We present two algorithms to manage the interaction between EVs and D-EVSE while maximizing EV drivers’ satisfaction in terms of reducing the waiting time for charging or discharging services and minimizing the stress placed on D-EVSE. We propose an optimization model based on Game Theory (GT) to manage the interaction between EVs and D-EVSE. We name this the decentralized-GT (D-GT) model. This model aims to find the optimal solution for EVs and D-EVSE based on the concept of win-win. We design a decentralized profit maximization algorithm to help D-EVSE take profit from the electricity price variation during the day when selling or buying electricity respectively to EVs or from the grid or EVs as discharging processes. We implement different scenarios to these models and show through analytical and simulation results that our proposed models help to minimize the D-EVSE stress level, increase the D-EVSE sustainability, maximize the D-EVSE profit, as well as maximize EV drivers’ satisfaction and reduce EVs’ waiting time.
5
Siebrits, Andre. "The role of great power war in the rise of Hegemons : a study of Dutch Hegemonic ascent in the modern world-system". Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/2787.
Pełny tekst źródłaStreszczenie:
Thesis (MA (Political Science))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: This study explores the claim that Great Power Wars are a necessary condition for successful hegemonic ascent in the modern world-system, primarily from the standpoint of World- Systems Analysis. This study advances the conception of hegemony primarily in economic and state terms, and it was investigated, by way of a historical case study, how the Thirty Years’ War (1618-1648) impacted the economic domains of agro-industrial production, commerce, and finance of the United Provinces of the Netherlands, and its main rival for systemic leadership, Hapsburg Spain. The variables utilised in the study were Great Power War, and the ‘material base’ of the state involved (both independent), the three abovementioned economic domains (intervening), and hegemony or defeat (dependent). The case study was primarily descriptive and explanatory, with the use of process-tracing in its compilation, and a method of within-case structured, focused comparison was utilised with the aim of tentatively producing standardised, generalised knowledge concerning the wider link between Great Power War and hegemony beyond the Dutch case. The findings of the study, although derived from only one historical case of hegemonic ascent in the modern world-system, strongly support the argument that Great Power War is necessary to secure the hegemony of the leading insular core state, which is physically removed from the fighting during the conflict, since the full mobilisation of its economy is effected, while the economies of most other core states are impaired, especially the main continental rival for hegemony. However, the ascending hegemon must also possess the requisite favourable ‘material base’. Further research on this topic is called for, given the potential destructiveness of a future Great Power War, and its role in establishing hegemony in the modern world-system.
AFRIKAANSE OPSOMMING: Hierdie studie ondersoek die bewering dat Groot Moontheid Oorloë ‘n noodsaaklike vereiste is vir suksesvolle hegemoniese bestyging in die moderne wêreld-sisteem, hoofsaaklik vanaf die standpunt van Wêreld-Sisteem Analise. Hierdie studie bevorder die konsepsie van hegemonie hoofsaaklik in ekonomiese en staat terme, en dit het ondersoek, deur middel van ‘n historiese gevallestudie, hoe die Dertig Jaar Oorlog (1618-1648) ingewerk het op die ekonomiese arenas van agri-industriële produksie, handel, and finansies van die Verenigde Provinsies van Nederland, en hul mededinger vir sistemiese leierskap, Spanje. Die veranderlikes wat in die studie ingespan was, was Groot Moontheid Oorlog, en die ‘materiële basis’ van die state in kwessie (onafhanlik), die drie bogenoemde ekonomiese arenas (albei tussenkomend), en hegemonie of nederlaag (afhanklik). Die gevallestudie was hoofsaaklik beskrywend en verduidelikend, en proses-nasporing (oftewel ‘process-tracing’) is in die samestelling daarvan benut, en ‘n metode van gestruktureerde, gefokusde vergelyking (oftewel ‘structured, focused comparison’) is gebruik binne die gevallestudie met die doel om tentatiewe gestandardiseerde en veralgemeende kennis te genereer wat bydra tot die verduideliking van die wyer skakel tussen Groot Moontheid Oorlog en hegemonie buite die geval van die Verenigde Provinsies. Die bevindinge van die studie, hoewel gegenereer aan die hand van slegs een historiese geval van hegemoniese bestyging in the moderne wêreld-sisteem, het sterk steun verleen aan die argument dat Groot Moontheid Oorloë nodig is om die hegemonie van die vernaamste insulêre kern staat te bewerkstellig, wat fisies verwyderd van die gevegte is tydends die oorlog, aangesien die volle mobilisasie van die ekonomie van hierdie staat bewerkstellig word, terwyl die ekonomieë van die meerderheid van die ander kernstate benadeel word, veral die vernaamste kontinentale mededinger om hegemonie. Die opkomende hegemoon moet egter ook oor die vereiste gunstige ‘materiële basis’ beskik. Verdere navorsing in hierdie veld word benodig, gegewe die waarskynlike vernietiging wat gesaai kan word deur ‘n toekomstige Groot Moontheid Oorlog, en die rol daarvan in die daarstelling van hegemonie in die moderne wêreld-sisteem.
6
Hlinecký, Tomáš. "Využití moderních inteligentních elektroinstalací pro osvětlení budov". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-217828.
Pełny tekst źródłaStreszczenie:
This diploma thesis concerns with problematic of modern intelligent wiring systems in buildings, meanwhile presents their advantages against old classical wiring systems. Also deals with utilization and properties of modern components for regulation, switching and light controlling. The first part deals with light sources and possible ways how to control the power of individual luminary sources. The second part discuss about utilization of radio-frequency systems in new buildings and also in reconstructions. In the next part is described a possibility of bus system for controlling building illumination scope with focusing to control system Nikobus. The last part is concerned on technical-economical evaluation of intelligent wiring systems by various manufacturers according to specific requirements.
7
Kaňovský, Jiří. "Energetické systémy v moderní výstavbě". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221202.
Pełny tekst źródła
8
Kuhn, Martin Raphael [Verfasser], Martin [Akademischer Betreuer] Otter, Ulrich [Gutachter] Wagner i Martin [Gutachter] Otter. "Design of a modern aircraft's electrical network system with focus on power quality and network stability via multi-level modeling / Martin Raphael Kuhn ; Gutachter: Ulrich Wagner, Martin Otter ; Betreuer: Martin Otter". München : Universitätsbibliothek der TU München, 2018. http://d-nb.info/1176701711/34.
Pełny tekst źródła
9
Rajkumar, Naganathy. "Novel algorithms for modern power systems". Thesis, City University London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390941.
Pełny tekst źródła
10
Anderson, Sharon Lee. "Reduced order power system models for transient stability studies". Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-09052009-040743/.
Pełny tekst źródła
11
Kryukova, N. V., Evgen Viktorovych Goncharov i I. V. Polyakov. "Modern monitoring systems of electric power lines". Thesis, NTU "KhPI", 2018. http://repository.kpi.kharkov.ua/handle/KhPI-Press/38909.
Pełny tekst źródła
12
Тугай, Дмитро Васильович. "Енергоефективність інтелектуальних систем електропостачання з напівпровідниковими перетворювачами електроенергії". Thesis, Харківський національний університет міського господарства ім. О. М. Бекетова, 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/29735.
Pełny tekst źródłaStreszczenie:
Дисертація на здобуття наукового ступеня доктора технічних наук за спеціальністю 05.09.03 – електротехнічні комплекси та системи. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2017.
В дисертаційній роботі розвинена сучасна теорія миттєвих активної і реактивної потужностей, що знайшла нове застосування при розробці методів розрахунку потужності втрат в трифазній СЕ, яка функціонує за принципами Smart Grid і містить енергозберігаючі напівпровідникові перетворювачі і накопичувачі енергії, здатні підтримувати в системі двоспрямований енергетичний потік. Отримані результати у сукупності є теоретичними узагальненнями і новим вирішенням важливої науково-прикладної проблеми – підвищення енергетичної ефективності систем електропостачання засобами силової електроніки. Підвищено точність розрахункових методів вибору параметрів силового активного фільтру і активного випрямляча – джерела напруги. Вирішено проблему обґрунтування критерію мінімізації енергетичних втрат і сформульовано теорему про мінімум втрат енергії в трифазних СЕ. Одержано універсальне розрахункове співвідношення, що дозволяє представити потужність втрат трифазної СЕ, як суму складових, кожна з яких обумовлена особливостями електромагнітних процесів. Обґрунтовано концепцію представлення сумарної потужності втрат через систему складових, що заснована на використанні p-q-r теорії миттєвої активної і реактивної потужностей. Отримані розрахункові співвідношення для визначення коефіцієнтів несиметрії струму за зворотної і за нульової послідовностями через складові потужності втрат в pqr координатах. Запропоновано метод визначення показників енергетичної ефективності СЕ з двоспрямованим енергетичним потоком, що заснований на використанні понять потоку енергії і втрат енергії. Ґрунтуючись на положеннях p-q-r теорії миттєвої активної і реактивної потужностей розроблено спосіб вимірювання складових сумарної потужності втрат енергії в трифазних СЕ. Всі теоретичні результати, отримані в дисертаційній роботі, перевірено на створених комп'ютерних моделях енергозберігаючих перетворювачів.Thesis for a Doctor’s degree in Engineering Science by specialty 05.09.03 – Electrical Engineering Complexes and Systems. National Technical University "Kharkov Polytechnic Institute", Kharkiv, 2017. The dissertation is developed to the modern theory of instantaneous active and reactive power for calculating losses power in Smart Grid three-phase energy supply system (ESS). The accuracy of calculation methods for selecting parameters of the power active filter and voltage-source active rectifier has been increased. An issue criteria substantiation to minimize energy losses and the theorem of minimum energy losses in the threephase ESS has been formulated. New universal ratio that can provide losses power of three-phase ESS as the sum of components, each of which is due to the peculiarities of electromagnetic processes is obtained. The concept of presenting the total losses power through the component that is based on the p-q-r theory of instantaneous active and reactive power is proved. The ratios for determine the asymmetry coefficients to the reverse current and the zero sequence components through losses power in pqr coordinates are obtained. Based on provisions of p-q-r theory of instantaneous active and reactive power the method of measuring components of total losses power in three-phase ESS have been developed. All the theoretical results, obtained in the thesis, in energy-saving converters computer models have been tested.
13
Тугай, Дмитро Васильович. "Енергоефективність інтелектуальних систем електропостачання з напівпровідниковими перетворювачами електроенергії". Thesis, НТУ "ХПІ", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/29732.
Pełny tekst źródłaStreszczenie:
Дисертація на здобуття наукового ступеня доктора технічних наук за спеціальністю 05.09.03 – електротехнічні комплекси та системи. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2017.
В дисертаційній роботі розвинена сучасна теорія миттєвих активної і реактивної потужностей, що знайшла нове застосування при розробці методів розрахунку потужності втрат в трифазній СЕ, яка функціонує за принципами Smart Grid і містить енергозберігаючі напівпровідникові перетворювачі і накопичувачі енергії, здатні підтримувати в системі двоспрямований енергетичний потік. Отримані результати у сукупності є теоретичними узагальненнями і новим вирішенням важливої науково-прикладної проблеми – підвищення енергетичної ефективності систем електропостачання засобами силової електроніки. Підвищено точність розрахункових методів вибору параметрів силового активного фільтру і активного випрямляча – джерела напруги. Вирішено проблему обґрунтування критерію мінімізації енергетичних втрат і сформульовано теорему про мінімум втрат енергії в трифазних СЕ. Одержано універсальне розрахункове співвідношення, що дозволяє представити потужність втрат трифазної СЕ, як суму складових, кожна з яких обумовлена особливостями електромагнітних процесів. Обґрунтовано концепцію представлення сумарної потужності втрат через систему складових, що заснована на використанні p-q-r теорії миттєвої активної і реактивної потужностей. Отримані розрахункові співвідношення для визначення коефіцієнтів несиметрії струму за зворотної і за нульової послідовностями через складові потужності втрат в pqr координатах. Запропоновано метод визначення показників енергетичної ефективності СЕ з двоспрямованим енергетичним потоком, що заснований на використанні понять потоку енергії і втрат енергії. Ґрунтуючись на положеннях p-q-r теорії миттєвої активної і реактивної потужностей розроблено спосіб вимірювання складових сумарної потужності втрат енергії в трифазних СЕ. Всі теоретичні результати, отримані в дисертаційній роботі, перевірено на створених комп'ютерних моделях енергозберігаючих перетворювачів.Thesis for a Doctor’s degree in Engineering Science by specialty 05.09.03 – Electrical Engineering Complexes and Systems. National Technical University "Kharkov Polytechnic Institute", Kharkiv, 2017. The dissertation is developed to the modern theory of instantaneous active and reactive power for calculating losses power in Smart Grid three-phase energy supply system (ESS). The accuracy of calculation methods for selecting parameters of the power active filter and voltage-source active rectifier has been increased. An issue criteria substantiation to minimize energy losses and the theorem of minimum energy losses in the threephase ESS has been formulated. New universal ratio that can provide losses power of three-phase ESS as the sum of components, each of which is due to the peculiarities of electromagnetic processes is obtained. The concept of presenting the total losses power through the component that is based on the p-q-r theory of instantaneous active and reactive power is proved. The ratios for determine the asymmetry coefficients to the reverse current and the zero sequence components through losses power in pqr coordinates are obtained. Based on provisions of p-q-r theory of instantaneous active and reactive power the method of measuring components of total losses power in three-phase ESS have been developed. All the theoretical results, obtained in the thesis, in energy-saving converters computer models have been tested.
14
Parveen, Tania. "Composite load model decomposition : induction motor contribution". Thesis, Queensland University of Technology, 2009. https://eprints.qut.edu.au/31301/1/Tania_Parveen_Thesis.pdf.
Pełny tekst źródłaStreszczenie:
In this thesis, a new technique has been developed for determining the composition of a collection of loads including induction motors. The application would be to provide a representation of the dynamic electrical load of Brisbane so that the ability of the power system to survive a given fault can be predicted. Most of the work on load modelling to date has been on post disturbance analysis, not on continuous on-line models for loads. The post disturbance methods are unsuitable for load modelling where the aim is to determine the control action or a safety margin for a specific disturbance. This thesis is based on on-line load models. Dr. Tania Parveen considers 10 induction motors with different power ratings, inertia and torque damping constants to validate the approach, and their composite models are developed with different percentage contributions for each motor. This thesis also shows how measurements of a composite load respond to normal power system variations and this information can be used to continuously decompose the load continuously and to characterize regarding the load into different sizes and amounts of motor loads.
15
Altamirano, Chavez Armando. "An efficient algorithm using Householder's formulas for the solution of faulted power systems". Thesis, Kansas State University, 1986. http://hdl.handle.net/2097/9896.
Pełny tekst źródła
16
Kamarudin, Syalwani. "Advanced Doherty power amplifier design for modern communication systems". Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/115269/.
Pełny tekst źródłaStreszczenie:
Mobile communication technologies are becoming increasingly sophisticated and have experienced rapid evolution over the last few decades, and this is especially true for the base station transmitter. In response to the ever increasing demand in communication traffic and data throughput, largely driven by video based social media platforms, both spectral and power efficient device and systems are needed to fulfil the requirements. In terms of energy consumption, the power amplifier is an important component, and although developing efficient technologies for handset equipment is important, it is the base station element of the communications system that poses the greater challenge, having to deal with many channels simultaneously, resulting in the need to linearly and efficiently amplify highly dynamic phase and amplitude modulated signals possessing very large peak-to-average power ratios, at high power levels. This unique set of challenges has led to continuous research to improve the efficiency of amplifiers that can accommodate such signals, and the Doherty architecture has now become the architecture-of-choice. However, most of the previous research studies demonstrate Doherty performance enhancement through a ‘conventional’ design approach that uses one input source and a passive power splitter to deliver power to each half of the Doherty structure. They do not emphasize the additional efficiency and other performance improvements that are possible in Doherty amplifiers when using two different, independent and phase coherent input sources, attached to the input path of both main and auxiliary amplifiers. IV The novel research work presented in this thesis introduces an optimised design approach for Doherty amplifier architectures with individual input sources, as well as detailing a measurement architecture that is necessary to characterise such structures, using separate, phase-coherent input sources in a realistic measurement scenario. Finally, following extensive characterisation of a number of promising architectures, investigations around efficiency enhancement are focused around the adaption of gate bias applied to the auxiliary amplifier device, and identifying, for the first time, what is possible by generating different shaping functions that relate bias voltage to the magnitude of the input signal. One completely new area of research and novelty introduced in this work for example shows how choosing the right shaping function can give improved linearity and importantly linearisability by producing a flat gain over dynamic range. Note that linearisability is important, and is defined here as the term used to describe the ease with which the non-linearities of a device or power amplifier can be corrected. It is often assumed in power amplifier design that efficiency and power are the most important parameters, and that modern digital pre-distortion (DPD) techniques can easily correct any non-linearity that may result. Industry is now finding that this is not the case however, and the type and nature of the non-linearity in terms to AM-AM and AM-PM distortion is very important in determining of the degree of linearization possible.
17
Hammer, Anders. "Analysis of IEEE Power System Stabilizer Models". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elkraftteknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-14035.
Pełny tekst źródłaStreszczenie:
Student:Anders HammerSupervisor:Kjetil UhlenContact:Daniel MotaCollaboration with:Voith HydroProblem descriptionIEEE (Institute of Electrical and Electronics Engineers) presented in 2005 a new PSS structure named IEEE PSS4B (Figure 0 1). Voith Hydro wants to analyse the pros and cons of using this new type compared to older structures. The PSS4B is a multi-band stabilizer that has three separate bands and is specially designed to handle different oscillation frequencies in a wide range. Until now, Voith Hydro has used the common PSS2B in their installations, but in the future they will probably start to implement the new PSS4B. This master thesis will seek to find an answer on following questions:•How should the PSS4B be tuned to give the best damping of the local and inter-area oscillation mode?•Will an implementation of PSS4B give a better result compared to PSS2B?•What are the pros and cons of PSS2B and PSS4B? Figure 0 1: The multi-band stabilizer, IEEE PSS4B [1].MethodIn order to test and compare different PSS models, a simple two-area network model is created in a computer simulation programme (SIMPOW). One of the generating units is a hydro generator, which has a model of a static excitation system made by Voith Hydro. This network is characterised by a poorly damped inter-area oscillation mode, and in addition some local oscillation modes related to each machine. Different PSS structures (PSS2B and PSS4B) are then tuned and installed in the excitation system of the hydro generator, in order to improve the stability of the network. Different tuning methods of the PSS4B are designed, tested and later compared with the more common stabilizer the PSS2B. Simplifications are made where parts of the stabilizer is disconnected in order to adapt the control structure to the applied network and its oscillations. Totally 5 different tuning methods are presented, and all these methods are based on a pole placement approach and tuning of lead/lag-filters. ResultsInitial eigenvalues of the different setups are analysed and several disturbances are studied in time domain analysis, in order to describe the robustness of the system. Figure 2 illustrates the rotor speed of the generator, where the different PSS’s are implemented. PSS4B is clearly resulting in increased damping of all speed oscillations in this network. The same results can also be seen in an eigenvalue analysis.Conclusion The best overall damping obtained in this master thesis occurs when the high frequency band of the PSS4B is tuned first, and in order to maximize the damping of the local oscillation mode in the network. The intermediate frequency band is then tuned as a second step, according to the inter-area oscillation mode. Results of this tuning technique show a better performance of the overall damping in the network, compared to PSS2B. The improvement of the damping of the inter-area oscillation mode is not outstanding, and the reason is that the applied machine is relative small compared to the other generating units in the network. The oscillation modes in the network (local and inter-area) have a relative small frequency deviation. A network containing a wider range of oscillation frequencies will probably obtain a greater advantage of implementing a multi-band stabilizer.
18
Shao, Jin. "Advanced Power Amplifiers Design for Modern Wireless Communication". Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc804973/.
Pełny tekst źródłaStreszczenie:
Modern wireless communication systems use spectrally efficient modulation schemes to reach high data rate transmission. These schemes are generally involved with signals with high peak-to-average power ratio (PAPR). Moreover, the development of next generation wireless communication systems requires the power amplifiers to operate over a wide frequency band or multiple frequency bands to support different applications. These wide-band and multi-band solutions will lead to reductions in both the size and cost of the whole system. This dissertation presents several advanced power amplifier solutions to provide wide-band and multi-band operations with efficiency improvement at power back-offs.
19
Stefopoulos, Georgios Konstantinos. "Quadratic power system modeling and simulation with application to voltage recovery and optimal allocation of VAr support". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29695.
Pełny tekst źródłaStreszczenie:
Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2010.Committee Chair: Meliopoulos, A. P. Sakis; Committee Member: Deng, Shijie; Committee Member: Divan, Deepakraj; Committee Member: Harley, Ronald; Committee Member: Taylor, David. Part of the SMARTech Electronic Thesis and Dissertation Collection.
20
Le, Dantec Jorge I. (Jorge Ignacio). "Assessing business models arising from the integration of distributed energy systems in the Chilean electric power system". Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/90714.
Pełny tekst źródłaStreszczenie:
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 83-84).
Electric power systems are more than just networks of generation, transmission and distribution assets. They are socio-technical systems, involving regulation, markets and technology availability. Presently, the dynamic relation among these aspects is creating new consumer needs in many power systems around the world, which incumbent electricity utilities do not seem well suited to meet at the required pace. In this context, the integration of Distributed Energy Systems (DESs) and their related business models appears as a flexible and often more affordable option to deliver value, by fulfilling the unmet needs of both consumers and utilities. To advice Chilean electric power system's stakeholders about the adequacy of a set of DES-related business models to Chilean needs, this document presents a systematic analysis, which focuses on the interrelation between business model attributes, involved DES technologies, and stakeholder needs. Specifically, an analytic framework is developed and applied to some business models currently operative in other markets, measuring their adequacy to meet stakeholders' needs in a set of envisioned scenarios of Chile's power system. This work provides a systematic tool for decision-making processes in selecting business models, when the decision must be made with qualitative data. Moreover, the evaluation in the Chilean system of actual business models shows results that should be valuable for consumers, utilities, and regulators.
by Jorge I. Le Dantec.
S.M. in Engineering and Management
21
Wang, Chun. "Methodologies and algorithms for fault locators in modern power systems". Thesis, University of the West of England, Bristol, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.392859.
Pełny tekst źródłaStreszczenie:
Following world wide deregulation of the electrical power industry, the requirements for high quality and highly reliable power supplies are increasing. Comprehensive and systematic computer based methodologies and algorithms for fault locators in power systems are needed to support reliable, independent and comprehensive fault diagnosis or accurate fault location, fast fault detection and correct fault classification. This thesis describes work to develop novel fault diagnosis techniques and accurate fault location algorithms for fault locators using system-wide information of modern power systems. Fast and efficient modern communication techniques make it possible to apply the novel fault locator system in practice. The fault diagnosis techniques use fault messages obtained from current and voltage sensors installed in radial and meshed networks respectively. A faulty section in the meshed network can be detected by analysing the network's topologic structure and the measurements of the fundamental frequency voltages obtained from voltage sensors; while for the radial network, current sensors are used to trace the path of a fault. The fault diagnosis techniques can work independently from protection devices, and circuit breakers, and can be implemented economically in the low- and medium-voltage power systems, because current and voltage sensors can be made cheaply. In order to achieve very accurate fault location for the EHV transmission systems with long transmission lines and complex network topology, algorithms based on the wavelet transform, travelling wave concept and GPS synchronisation have been developed. When a fault occurs, fault generated transient waves propagate from fault point to line terminals and then to the other nodes in the whole network. Fault transient detectors are installed at nodes in the meshed network, at substations and customer terminals in the radial system to capture the time of fault transient signal arrival. From the time recorded and topologic network structure, very accurate fault location can be achieved. The thesis also describes and compares applications of digital Fourier transform, least squares method and Kalman filters for fast measurements in current and voltage sensors, for fault classification and fault detection, and the wavelet transform used in fault transient detectors. Methodologies and algorithms developed have been validated by ATP/EMTP simulation on different networks, such as, traditional twosource system and IEEE 14-bus system. The maIn advantage of the developed methodologies and algorithms for fault locators in power systems is the use of system-wide fault messages in the electrical networks. The fault locators will efficiently support the operators in the control centres and relevant substations with clear fault information allowing them to take suitable actions for fault emergency and restoration of power supplies. This will be beneficial in reducing the outage time required for inspection, damage repair and restoration of the power supply. Reliability, security and power quality will be improved for the customers.
22
Nteka, Makhetsi Flora. "Development and assessment of reduced order power system models". Thesis, Cape Peninsula University of Technology, 2013. http://hdl.handle.net/20.500.11838/1088.
Pełny tekst źródłaStreszczenie:
Thesis submitted in fulfilment of the requirements for the degree
Master of Technology: Electrical Engineering
in the Faculty of Engineering
at the Cape Peninsula University of Technology
2013The demand for electrical energy has kept on increasing, thus causing power systems to be more complex and bringing the challenging problems of electrical energy generation, transmission, stability, as well as storage to be examined more thoroughly. With the advent of high-speed computation and the desire to analyze increasingly complex behaviour in power systems, simulation techniques are gaining importance and prevalence. Nevertheless, while simulations of large, interconnected complex power systems are feasible, they remain time-consuming. Moreover, the models and parameters used in simulations are uncertain, due to measurement uncertainty, the need to represent a complex behaviour with low-order models, and the inherent changing nature of the power system. This research explores the use of a model reduction technique and the applications of a Real-Time Digital Simulator (RTDS) to reduce the uncertainty in large-scale complex power system models. The main goal of the research is to develop a reduced order model and to investigate the applications of the RTDS simulator in reduction of large, interconnected power systems models. The first stage of the study is to build and simulate the full model of the power system using the DigSILENT and RTDS simulators. The second phase is to apply model reduction technique to the full model and to determine the parameters in the reduced-order model as well as how the process of reduction increases this model uncertainty. In the third phase the results of the model reduction technique are compared based on the results of the original model - IEEE standard benchmark models has been used. The RTDS was used for comparative purposes. The thesis investigations use a particular model reduction technique as Coherency based Method. Though the method ideas are applicable more generally, a concrete demonstration of its principles is instructive and necessary. Further, while this particular technique is not relevant to every system, it does apply to a broad class of systems and illustrates the salient features of the proposed methodology. The results of the thesis can be used in the development of reduced models of complex power systems, simulation in real-time during power system operation, education at universities, and research. Keywords: IEEE benchmark models, reduced models, Coherency based Method, DigSILENT, RTDS, model uncertainty, power system stability
23
Mazumdar, Joy. "System and method for determining harmonic contributions from nonlinear loads in power systems". Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/23215.
Pełny tekst źródłaStreszczenie:
The objective of this research is to introduce a neural network based solution for the problem of measuring the actual amount of harmonic current injected into a power network by an individual nonlinear load. Harmonic currents from nonlinear loads propagate through the system and cause harmonic pollution. As a result, voltage at the point of common coupling (PCC) is rarely sinusoidal. The IEEE 519 harmonic standard provides customer and utility harmonic limits and many utilities are now requiring their customers to comply with IEEE 519. Measurements of the customer’s current at the PCC are expected to determine the customer’s compliance with IEEE 519. However, results in this research show that the current measurements at the PCC are not always reliable in that determination. In such a case, it may be necessary to determine what the customer’s true current harmonic distortions would be if the PCC voltage could be a pure sinusoidal voltage. However, establishing a pure sinusoidal voltage at the PCC may not be feasible since that would mean performing utility switching to reduce the system impedance. An alternative approach is to use a neural network that is able to learn the customer’s load admittance. Then, it is possible to predict the customer’s true current harmonic distortions based on mathematically applying a pure sinusoidal voltage to the learned load admittance. The proposed method is called load modeling. Load modeling predicts the true harmonic current that can be attributed to a customer regardless of whether a resonant condition exists on the utility power system. If a corrective action is taken by the customer, another important parameter of interest is the change in the voltage distortion level at the PCC due to the corrective action of the customer. This issue is also addressed by using the dual of the load modeling method. Topologies of the neural networks used in this research include multilayer perceptron neural networks and recurrent neural networks. The theory and implementation of a new neural network topology known as an Echo State Networks is also introduced. The proposed methods are verified on a number of different power electronic test circuits as well as field data. The main advantages of the proposed methods are that only waveforms of voltages and currents are required for their operation and they are applicable to both single and three phase systems. The proposed methods can be integrated into any existing power quality instrument or can be fabricated into a commercial standalone instrument that could be installed in substations of large customer loads, or used as a hand-held clip on instrument.
24
Raoofsheibani, Davood [Verfasser]. "Online Power System Security Analysis and State Prediction : Enhanced Power System Models and Tools / Davood Raoofsheibani". Düren : Shaker, 2021. http://d-nb.info/1240853947/34.
Pełny tekst źródła
25
Persson, Jonas. "Linear models of non-linear power system components". Licentiate thesis, KTH, Electrical Systems, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1415.
Pełny tekst źródła
26
Cresswell, Charles. "Steady state load models for power system analysis". Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/3846.
Pełny tekst źródłaStreszczenie:
The last full review of load models used for power system studies occurred in the 1980s. Since then, new types of loads have been introduced and system load mix has changed considerably. The examples of newly introduced loads include drive-controlled motors, low energy consumption light sources and other modern power electronic loads. Their numbers have been steadily increasing in recent years, a trend which is expected to escalate. Accordingly, the majority of load models used in traditional power system studies are becoming outdated, as they are unable to accurately represent power demand characteristics of existing and future loads. Therefore, in order to accurately predict both active and non-active power demand characteristics of aggregated modern power system loads in different load sectors (e.g. residential, commercial or industrial), existing load models should be updated and new models developed. This thesis aims to fill this gap by developing individual, generic and aggregated steady state models of the most common loads in use today, as well as of those expected to show significant growth in the future. The component-based approach is adopted for load modelling, where individual load models are obtained in detailed simulations of physical devices. Whenever possible, the developed individual load models are validated by measurements. These detailed individual load models are then simplified and expressed as equivalent circuit and analytical models, which allowed the establishment of generic load models that can be easily aggregated. It should be noted that since all non-active power characteristics are correctly represented, the developed aggregated load models allow for a full harmonic analysis, which is not the case with the standard steady state load models. Therefore, the proposed load models form an extensive library of comprehensive load models that are suitable for use in multiple areas of power system research. Based on the results of research related to typical domestic/residential sector load mix, the newly developed load models are aggregated and then applied to a typical UK/Scotland distribution network. Considerable differences are seen between network characteristics of newly proposed and previously developed models. The voltage distortion of a typical distribution system bus is investigated, and it is shown that distortion of the system voltage is likely to increase significantly in the future. The results of the presented research also suggest that neglecting the harmonic characteristics from the set of general load attributes may introduce errors in standard load flow studies.
27
Scruggs, James N. "Power system availability determination through Petri net simulation". Ohio : Ohio University, 1995. http://www.ohiolink.edu/etd/view.cgi?ohiou1178910568.
Pełny tekst źródła
28
Yuan, Lin. "Design space re-engineering for power minimization in modern embedded systems". College Park, Md. : University of Maryland, 2006. http://hdl.handle.net/1903/3651.
Pełny tekst źródłaStreszczenie:
Thesis (Ph. D.) -- University of Maryland, College Park, 2006.Thesis research directed by: Electrical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
29
Wang, Longfei. "High Performance Distributed On-Chip Voltage Regulation for Modern Integrated Systems". Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7590.
Pełny tekst źródłaStreszczenie:
Distributed on-chip voltage regulation where multiple voltage regulators are distributed among different locations of the chip demonstrates advantages as compared to on-chip voltage regulation utilizing a single voltage regulator. Better on-chip voltage noise performance and faster transient response can be realized due to localized voltage regulation. Despite the advantages of distributed on-chip voltage regulation, unbalanced current sharing issue can occur among each voltage regulator, which has been demonstrated to deteriorate power conversion efficiency, stability, and reliability of the power delivery network. An effective balanced current sharing scheme that can be applied to most voltage regulator types is proposed to balance the current sharing. Furthermore, a relatively high on-chip temperature induced by increased power density leads to prominent voltage regulator performance degradations due to aging. The emerging type of digital low-dropout regulator is investigated regarding aging induced transient and steady state performance degradations. Reliability enhancement techniques for digital low-dropout regulators are developed and verified. Such techniques introduce negligible power and area overhead and do not affect the normal operations of digital low-dropout regulators. Reliability enhancement techniques also reduce the area overhead needed to mitigate aging induced performance degradations. Area overhead saving further translates into more space for increased number of distributed on-chip voltage regulators, enabling scalable on-chip voltage regulation.
30
Demiray, Turhan Hilmi. "Simulation of power system dynamics using dynamic phasor models /". Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17607.
Pełny tekst źródła
31
Holm, Gustav. "Automated Model Transformation for Cyber-Physical Power System Models". Thesis, KTH, Skolan för teknikvetenskap (SCI), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-214750.
Pełny tekst źródłaStreszczenie:
Standardized information and mathematicalmodels, which model the characteristics of the power generationand power transmission systems, are requirements for futuredevelopment and maintenance of different applications tooperate the electrical grid. Available databases such as Nordpoolprovides large amounts of data for power supply and demand [1].The typical misconception with open availability of data is thatexisting power system software tools can interact and process thisdata. Difficulties occur mainly because of two reasons. The firston is the amount of data produced. When the topology of theelectrical grid changes e.g. when a switch opens or closes, the flowof electrical power changes. This event produce changes ingeneration, transmission and distribution of the energy anddifferent data sets are produced. The second problem is therepresentation of information [2]. There are a limited number ofsoftware tools that can analyze this data, but each software toolrequires a specific data format structure to run. Dealing withthese difficulties requires an effective way to transform theprovided data representation into new data structures that canbe used in different execution platforms. This project aims tocreate a generic Model-to-Text (M2T) transformation capable oftransforming standardized power system information modelsinto input files executable by the Power System Analysis Tool(PSAT). During this project, a working M2T transformation wasnever achieved. However, missing functionality in someprograms connected to sub processes resulted in unexpectedproblems. This led to a new task of updating the informationmodel interpreter PyCIM. This task is partially completed andcan load basic power system information models.
32
Chevalier, Samuel Chapman. "Inference, estimation, and prediction for stable operation of modern electric power systems". Thesis, Massachusetts Institute of Technology, 2021. https://hdl.handle.net/1721.1/130842.
Pełny tekst źródłaStreszczenie:
Thesis: Ph. D. in Mechanical Engineering and Computation, Massachusetts Institute of Technology, Department of Mechanical Engineering, February, 2021Cataloged from the official PDF of thesis.
Includes bibliographical references (pages 261-277).
To keep pace with social-ecological disruptions and technological progressions, electrical power systems must continually adapt. In order to address the stability-related challenges associated with these adaptations, this thesis develops a set of analytically rigorous yet practically oriented methods for ensuring the continued stability of modern power systems. By leveraging inference, estimation, and predictive modeling techniques, the proposed methods capitalize on the unprecedented amount of real time data emerging from modernizing smart grids. For each method, we provide simulated test results from IEEE benchmark systems. Newly deployed Phasor Measurement Units (PMUs) are observing the presence of detrimental low frequency forced oscillations (FOs) in transmission grid networks. To begin this thesis, we address the problem of locating the unknown sources of these FOs.
To perform source identification, we develop an equivalent circuit transformation which leverages suitably constructed transfer functions of grid elements. Since FO sources appear in this equivalent circuit as independent current injections, a Bayesian framework is applied to locate the most probable source of these injections. Subsequently, we use our equivalent circuit to perform a systematic investigation of energy-based source identification methods. We further leverage this equivalent circuit transformation by developing "plug-and-play" stability standards for microgrid networks that contain uncertain loading configurations. As converter-based technology declines in cost, microgrids are becoming an increasingly feasible option for expanding grid access. Via homotopic parameterization of the instability drivers in these tightly regulated systems, we identify a family of rotational functions which ensure that no eigenmodes can be driven unstable.
Any component which satisfies the resulting standards can be safely added to the network, thus allowing for plug-and-play operability. High-fidelity linearized models are needed to perform both FO source identification and microgrid stability certification. Furthermore, as loss of inertia and real-time observability of grid assets accelerate in tandem, real-time linearized modeling is becoming an increasingly useful tool for grid operators. Accordingly, we develop tools for performing real-time predictive modeling of low frequency power system dynamics in the presence of ambient perturbations. Using PMU data, we develop a black-box modeling procedure, known as Real-Time Vector Fitting (RTVF), that takes explicit account for initial state decay and concurrently active input signals. We then outline a proposed extension, known as stochastic-RTVF, that accounts for the corrupting effects of unobservable stochastic inputs.
The surrogate modeling utilized by vector fitting can also be applied to the steady state power flow problem. Due to an unprecedented deployment of distributed energy resources, operational uncertainty in electrical distribution networks is increasing dramatically. To address this challenge, we develop methodology for speeding up probabilistic power flow and state estimation routines in distribution networks. We do so by exploiting the inherently low-rank nature of the voltage profile in these systems. The associated algorithms dynamically generate a low-dimensional subspace which is used to construct a projection-based reduced order model (ROM) of the full nonlinear system. Future system solves using this ROM are highly efficient.
by Samuel Chapman Chevalier.
Ph. D. in Mechanical Engineering and Computation
Ph.D.inMechanicalEngineeringandComputation Massachusetts Institute of Technology, Department of Mechanical Engineering
33
Phung, James Hon-Hoe. "Power Modeling in Modern Server Systems: An Examination of Various Novel Approaches". Thesis, The University of Sydney, 2019. https://hdl.handle.net/2123/21376.
Pełny tekst źródłaStreszczenie:
As Cloud and other distributed networks become more complex and new virtualization technologies are increasingly adopted, there is an increasing need for versatile solutions that can effectively measure the energy consumption incurred by users of such networks and use this information to schedule user jobs with the goal of maximizing energy efficiency. In this thesis, existing work in power modeling involving performance monitoring events and the Running Average Power Limit was reviewed. While substantial work has been done in these areas, the focus has been on a narrow range of use cases. To address the lack of versatility of existing power meters, three lightweight software-based virtual power meters were developed. Utilizing simple but powerful application-agnostic power models, they offer similar performances to existing power models but have minimal overheads and are portable for use in a variety of systems. The first two power meters use performance event counters and the RAPL feature respectively to estimate power use. The third power meter is an enhanced power meter incorporating features from these two earlier power meters. Additionally, the enhanced power meter can estimate power use on a per-application basis. Furthermore, a systematic framework PowerSave was developed to analyze and evaluate energy use and performance patterns for a variety of workloads for different types of server systems under different CPU power limits. Results from PowerSave and power modeling experiments show that CPU power use accounts for most of a server's power consumption and that there is a high level of correlation between CPU power use and server power use.
34
Shridevi, Rajesh Jayashankara. "Emerging Security Threats in Modern Digital Computing Systems: A Power Management Perspective". DigitalCommons@USU, 2019. https://digitalcommons.usu.edu/etd/7483.
Pełny tekst źródłaStreszczenie:
Design of computing systems — from pocket-sized smart phones to massive cloud based data-centers — have one common daunting challenge : minimizing the power consumption. In this effort, power management sector is undergoing a rapid and profound transformation to promote clean and energy proportional computing. At the hardware end of system design, there is proliferation of specialized, feature rich and complex power management hardware components. Similarly, in the software design layer complex power management suites are growing rapidly. Concurrent to this development, there has been an upsurge in the integration of third-party components to counter the pressures of shorter time-to-market. These trends collectively raise serious concerns about trust and security of power management solutions.
In recent times, problems such as overheating, performance degradation and poor battery life, have dogged the mobile devices market, including the infamous recall of Samsung Note 7. Power outage in the data-center of a major airline left innumerable passengers stranded, with thousands of canceled flights costing over 100 million dollars. This research examines whether such events of unintentional reliability failure, can be replicated using targeted attacks by exploiting the security loopholes in the complex power management infrastructure of a computing system.
At its core, this research answers an imminent research question: How can system designers ensure secure and reliable operation of third-party power management units? Specifically, this work investigates possible attack vectors, and novel non-invasive detection and defense mechanisms to safeguard system against malicious power attacks. By a joint exploration of the threat model and techniques to seamlessly detect and protect against power attacks, this project can have a lasting impact, by enabling the design of secure and cost-effective next generation hardware platforms.
35
Persson, Jonas. "Bandwidth-reduced Linear Models of Non-continuous Power System Components". Doctoral thesis, Stockholm : Electric Power Systems, School of Electrical Engineering, Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3984.
Pełny tekst źródła
36
Branney, Sean J. "Comparison and development of hurricane electrical power system damage models". Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/5657.
Pełny tekst źródłaStreszczenie:
Thesis (M.S.)--University of Missouri-Columbia, 2008.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 25, 2008) Includes bibliographical references.
37
Hockenberry, James Richard. "Evaluation of uncertainty in dynamic, reduced-order power system models". Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/46685.
Pełny tekst źródłaStreszczenie:
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.Includes bibliographical references (leaves 209-213).
With the advent of high-speed computation and the desire to analyze increasingly complex behavior in power systems, simulation techniques are gaining importance and prevalence. However, while simulations of large, interconnected power systems are feasible, they remain time-consuming. Additionally, the models and parameters used in simulations are uncertain, due to measurement uncertainty, the need to approximate complex behavior with low-order models and the inherent changing nature of the power system. This thesis explores the use of model reduction techniques to enable the study of uncertainty in large-scale power system models. The main goal of this thesis is to demonstrate that uncertainty analyses of transient simulations of large, interconnected power systems are possible. To achieve this, we demonstrate that a basic three stage approach to the problem yields useful results without significantly increasing the computational burden. The first stage is to reduce the order of the original power system model, which reduces simulation times and allows the system to be simulated multiple times in a reasonable time-frame. Second, the mechanics of the model reduction are closely studied; how uncertainties affect the reduction process and the parameters in the reduced-order model as well as how the process of reduction increases uncertainty are of particular interest. Third, the reduced-order model and its accompanying uncertainty description are used to study the uncertainty of the original model. Our demonstration uses a particular model reduction technique, synchronic modal equivalencing (SME), and a particular uncertainty analysis method, the probabilistic collocation method (PCM). Though our ideas are applicable more generally, a concrete demonstration of the principle is instructive and necessary. Further, while these particular techniques are not relevant to every system, they do apply to a broad class of systems and illustrate the salient features of our methodology. As mentioned above, a detailed analysis of the model reduction technique, in this case SME, is necessary. As an ancillary benefit of the thesis work, interesting theoretical results relevant to the SME algorithm, which is still under development, are derived.
by James R. Hockenberry.
Ph.D.
38
Abur, Ali. "Knowledge-based power flow models and array processor-based power flow solutions for fast prediction of system states /". The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487261553057511.
Pełny tekst źródła
39
Du, Zhaobin, i 杜兆斌. "Area COI-based slow frequency dynamics modeling, analysis and emergency control for interconnected power systems". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B4175783X.
Pełny tekst źródła
40
Ha, Dinh Truc. "Line outage vulnerabilities of power systems : models and indicators". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAT018/document.
Pełny tekst źródłaStreszczenie:
La vulnérabilité des systèmes électriques est l'un des problèmes liés à leur complexité. Il a fait l’objet d’une attention croissante des chercheurs au cours des dernières décennies. Malgré cela, les phénomènes fondamentaux qui régissent la vulnérabilité du système ne sont pas encore bien compris.Comprendre comment la vulnérabilité des réseaux électriques émerge de leur topologie est la motivation principale du présent travail. Pour cela, le présent travail de recherché propose une nouvelle méthode pour évaluer la vulnérabilité des systèmes électriques et identifier leurs éléments les plus critiques. La méthode permet d’avoir une bonne compréhension des liens entre la topologie d’un réseau et sa vulnérabilité à des pertes d’ouvrages (lignes ou transformateurs).La première partie de ce travail consiste en une analyse critique des approches rencontrées dans la littérature, s’appuyant sur la théorie des graphes, pour analyser la vulnérabilité des réseaux électriques. Les résultats fournis par ces approches pour quatre réseaux IEEE sont comparés à ceux fournis par une analyse de contingence de référence, basée sur une résolution d’un load-flow AC. Des avantages et inconvénients de chaque approche est tirée une méthode améliorée pour l'évaluation de la vulnérabilité des réseaux électriques aux pertes d’ouvrage. Cette méthode est basée sur une approximation courant continue du load flow.La deuxième partie propose une nouvelle approche basée sur la théorie spectrale des graphes et son utilisation pour la résolution d’un load flow DC. Elle permet de mieux comprendre comment la vulnérabilité des réseaux électriques et leurs composants critiques émergent de la topologie du graphe sous-jacent au réseauThe vulnerability of electrical systems is one of the problems related to their complexity. It has received increasing attention from researchers in recent decades. Despite this, the fundamental phenomena that govern the vulnerability of the system are still not well understood.Understanding how the vulnerability of power systems emerges from their complex organization is, therefore, the main motivation of the present work. It proposes the definition of a standard method to assess the vulnerability of power systems and identify their most critical elements. The method enables a better understanding of the links between the topology of the grid and the line outage vulnerabilities.The first part of this research work offers a critical review of literature approaches used to assess system vulnerability. The results provided by these approaches for four IEEE test systems are confronted to a reference contingency analysis using AC power flow calculations. From these analyses, pros and cons of each approach are outlined. An improved method for assessment of system vulnerability to line outages is defined from this confrontation. It is based on DC load flow and graph theory.The second part proposes a new approach based on spectral graph theory and solving of DC power flow to identify how system vulnerability and critical components emerge from the power network topology
41
廖德寧 i Te-Ning Liao. "A vertical axial-field generator and its stability in power system". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1986. http://hub.hku.hk/bib/B31207789.
Pełny tekst źródła
42
Ly, Cuong. "Reliability study of the Callide power station electrical system". Thesis, Queensland University of Technology, 1997. https://eprints.qut.edu.au/36023/1/36023_Ly_1997.pdf.
Pełny tekst źródłaStreszczenie:
The reliable operation of the electrical system at Callide Power Station is of extreme importance to the
normal everyday running of the Station.
The electrical system configuration and hardware are inherently very reliable. However, in all cases the
failure of components such as circuit breakers, switchboards, and transformers would directly or indirectly
effect the Station's capability to generate at full load capacity and hence maximise revenue.
This study has applied the principles of reliability and has utilised a reliability software package to do an
analysis on the electrical system at Callide Power Station.
The study analyses other possible system configurations that could increase the reliability of the Station.
The study identifies priority maintenance on load points displaying high reliability indices. An analysis
was done on the impact of unusual system configurations such as Boiler Feed Pump motor startups.
Using the results from the study an appropriate level of maintenance was suggested for the current
Callide electrical system configuration and recommendations on the replacement of some 41 SV circuit
breaker tripping toggles was made.
43
Pourbeik, Pouyan. "Design and coordination of stabilisers for generators and FACTS devices in multimachine power systems /". Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09php877.pdf.
Pełny tekst źródła
44
Schürmans, Stefan [Verfasser], Rainer [Akademischer Betreuer] Leupers i Tobias [Akademischer Betreuer] Gemmeke. "Power Estimation on Electronic System Level using Linear Power Models / Stefan Schürmans ; Rainer Leupers, Tobias Gemmeke". Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1171323808/34.
Pełny tekst źródła
45
PIRES, Robson Celso. "Complex-Valued Steady-State Models as Applied to Power Flow Analysis and Power System State Estimation". reponame:Repositório Institucional da UNIFEI, 2018. http://repositorio.unifei.edu.br/xmlui/handle/123456789/1359.
Pełny tekst źródłaStreszczenie:
Submitted by repositorio repositorio (repositorio@unifei.edu.br) on 2018-06-15T13:12:49Z
No. of bitstreams: 1
tese_2018_pires_robson.pdf: 2114807 bytes, checksum: d730bc3798b4777ca67282b62e72c7e0 (MD5)Made available in DSpace on 2018-06-15T13:12:49Z (GMT). No. of bitstreams: 1 tese_2018_pires_robson.pdf: 2114807 bytes, checksum: d730bc3798b4777ca67282b62e72c7e0 (MD5) Previous issue date: 2018-06
Nonlinear systems of equations in complex domain are frequently encountered in applied mathematics, e.g., power systems, signal processing, control theory, neural networks and biomedicine, to name a few. The solution of these problems often requires a first- or second-order approximation of these nonlinear functions to generate a new step or descent direction to meet the solution iteratively. However, such methods cannot be applied to real functions of complex variables because they are necessarily non-analytic in their argument, i.e., the Taylor series expansion in their argument alone does not exist. To overcome this problem, the nonlinear function is usually redefined as a function of the real and imaginary parts of its complex argument so that standard methods can be applied. Although not widely known, it is possible to build an expansion of these nonlinear functions in its original complex variables by noting that functions of complex variables can be analytic in their argument and its complex conjugate as a whole. This property lies in the fact that if a function is analytic in the space spanned by ℜ{} and ℑ{}in ℝ, it is also analytic in the space spanned by and * in ℂ. The main contribution of this work is the application of this methodology to a complex Taylor series expansions aiming algorithms commonly used for solving complex-valued nonlinear systems of equations emerged from power systems problems. In our proposal, a complex-valued power ow analysis (CV PFA) model solved by Newton-Raphson method is revisited and enhanced. Nonetheless, especially emphasis is addressed to Gauss-Newton method when derived in complex domain for solving power system state estimation (CV PSSE) problems, whichever they are applied in transmission or distribution systems. The factorization method of the complex Jacobian matrices emerged from CV PFA and CV PSSE approaches is the Three Angle Complex Rotation (TACR) algorithm that comes from the Givens Rotations algorithm in real domain. In this research one demonstrates that Wirtinger derivatives can lead to greater insights in the structure of both problems, i.e., CV PFA & CV PSSE. Moreover, it can often be exploited to mitigate computational overhead, storage cost and enhance the network's component modeling as FACTS devices, e.g., STATCOM, VSC-HVDC, besides easily handle PMU measurements and embedding new technologies towards smart grids. Finally, in order to add numerical robustness, a fourth-order Levenberg-Marquardt algorithm is employed to the CV PFA & CV PSSE approaches because of its nice bi-quadratic convergence property, instead of the well-known quadratic convergence property of the classical Newton-Raphson and Gauss-Newton algorithms. Recall that these latter algorithms are prone to collapse when the power system network is ill-conditioned, i.e., it is heavily loaded or presents branches with high R/X ratio. These results are partially presented in this thesis because they are still under study and development. But most of them will appear in forthcoming papers submitted to IEEE-PES Transactions on Power Systems and coming up Top Conferences.
46
Adepetu, Adeyemi (Adeyemi Adetayo). "Exploring neighborhood power production technologies and business models for developing economies". Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/100087.
Pełny tekst źródłaStreszczenie:
Thesis: S.M., Massachusetts Institute of Technology, Engineering Systems Division, 2014."September 2014." Cataloged from PDF version of thesis.
Includes bibliographical references (pages 46-47).
A Neighborhood Power Producer business solution, which aggregates customers and therefore employs economies of scale, is one solution to the energy access issue of most developing economies. In this approach, entrepreneurs contract with a group of colocated residents or businesses to provide modem energy services. This service can be grid-tied or off-grid, serving as either backup power to the central electricity grid or as primary power, depending on access to the electric grid and/or the quality and availability of power. These systems are essentially micro-grids with distributed generation. These developing world Neighborhood Power Producers will also benefit from the rising demand for a more distributed electric grid as a solution to the threat of adverse weather like hurricanes and super storms in developed economies. Cyber security threats are also leading to increased research into distributed power generation systems. This provides technological advances that are powered by investments in developed markets. The developing economies can essentially leapfrog their more developed counterparts with regards to grid-resiliency. The goal of this thesis is to examine broad trends in the Neighborhood Power Producer business model and what strategies are necessary for business sustainability in the short, mid, and longer term.
by Adeyemi Adepetu.
S.M.
47
Farahmand, Hossein. "Integrated Power System Balancing in Northern Europe - Models and Case Studies". Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elkraftteknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-16864.
Pełny tekst źródłaStreszczenie:
Maintaining a continuous balance between generation and load is crucial for the safeguarding of the power systems. In order to effectively deal with the various uncertainties that contribute to the real-time imbalance in liberalised power systems, Transmission System Operators (TSOs) procure and employ the so-called balancing services through balancing markets. In Europe, though such mechanisms are well in place at the national level, the potential of multinational balancing markets has not been fully exploited (with the exception of the Nordic system and various pilot projects). This thesis analyses the potential for integrating the balancing power markets in northern Europe, including the Nordic system, Germany and the Netherlands. It addresses the twin issues of the procurement and employment of cross-border balancing services by using mathematical models. Beginning with an outline of the role of balancing markets in Europe, an overview of existing balancing markets in the northern European system is presented. A discussion on the cross-border balancing arrangements is then carried out, paving the way for quantitative analysis. A quantitative analyses of the multinational balancing markets are carried out, both in terms of attainable socio-economic cost savings, and their effect on the exchange of regional balancing services and generation dispatch. In this respect, two cases of balancing market integration are analysed: the current state with separate balancing markets, and the anticipated state of full integration of these markets. In the proposed modelling approach a two-step model is used, representing the day-ahead and balancing markets, respectively. First, the day-ahead market is modelled as a common market for the whole European continent. Simultaneously, reserve procurement for northern Europe is modelled. Available transmission capacity is allocated implicitly to the balancing services exchange, based on the trade-off between day-ahead energy and balancing capacity exchange. Next, the balancing energy market is modelled as a real-time power dispatch on the basis of the day-ahead market clearing results and simulated imbalances. Detailed results illustrate the consequences of market integration between two synchronous areas on procured and activated reserves, dispatch of generators, and power flows. The profitability of balancing market integration is quantified by the observed cost savings obtained due to the use of cheaper balancing resources and less activation of reserves caused by imbalance netting. The implementation of cross-border balancing entails both qualitative and quantitative analyses of different balancing exchange scenarios. This thesis focuses on the qualitative studies of cross-border balancing arrangements together with the quantitative analysis of cross-border balancing. The methodology developed in the thesis enables the study of the benefits of integrating the northern European balancing markets, and the resulting exchange of balancing services among the Nordic countries, Germany and the Netherlands. The multinational balancing market can be adapted to capture the effect of different market integration scenarios. The presented modelling approach includes a flow-based market model, which takes into account physical power flows and loop flows, especially suitable for the European systems with highly meshed transmission grids. A four tiered sequential approach is used to organize the primary contributions of the research work, as highlighted by the four distinct publications arising out of it. Tier 1: An optimal methodology for reserve activation in the Nordic system is established. Tier 2: Using the first tier as the basis, a cross-border reserves procurement algorithm is proposed for an integrated European system. Superimposing Tier 2 on Tier 1 results in a bottom-up approach of capturing the full spectrum of reserve procurement and activation for integrated balancing markets. Tier 3: The profitability of balancing market integration is brought forward through both weekly and yearly analysis on the basis of mathematical models developed in Tier 1 and 2. Tier 4: It is shown that the flexibility concerns warranted by penetration of renewable energy resources can be well addressed by using the developed framework of cross-border balancing market integration. A case study of a future power system (in 2030) with wind energy penetration has been employed in this regard. The results include the optimal distribution of balancing reserve capacity allocations for procurement among the constituent countries, and the optimal exchange of balancing energy that ensues upon activating these capacity reserves. An annual analysis of the post-integration scenario results demonstrates the significant cost savings that are achievable under the framework of multinational balancing markets. The results also demonstrate the potential for increased production flexibility, in light of increased wind energy penetration in the future operation of power systems through the mechanism of multinational balancing markets.
48
Guo, Song. "Adaptive parameter estimation of power system dynamic models using modal information". Thesis, Durham University, 2014. http://etheses.dur.ac.uk/10576/.
Pełny tekst źródłaStreszczenie:
Knowledge of the parameter values of the dynamic generator models is of paramount importance for creating accurate models for power system dynamics studies. Traditionally, power systems consists of a relatively limited numbers of large power stations and the values of generator parameters were provided by manufacturers and validated by utilities. Recently however, with the increasing penetration of distributed generation, the accuracy of these models and parameters cannot be guaranteed. This thesis addresses the above concerns by developing a methodology to estimate the parameter values of a power system dynamic model online, employing dynamic system modes, i.e. modal frequencies and damping. The dynamic modes are extracted from real-time measurements. The aim of the proposed methodology is to minimise the differences between the observed and modelled modes of oscillation. It should be emphasised that the proposed methodology does not aim to develop the dynamic model itself but rather modify its parameter using WAMS measurements. The developed methodology is general and can be used to identify any generator parameters., However, thesis concentrates on the estimation of generator inertia constants. The results suggest that the proposed methodology can estimate inertias and replicate the dynamic behaviour of the power system accurately, through the inclusion of pseudo-measurements in the optimisation process. The pseudo-measurements not only improves the accuracy of the parameter estimation but also the robustness of it. Observability, a problem when there are fewer numbers of measurements than the numbers of parameters to be estimated, has also been successfully tackled. It has been shown that the damping measurements do not influence the accuracy and robustness of generator inertia estimation significantly.
49
Tong, Y.-K. "Circuit models and simulations of surge attentuation on HV transmission system". Thesis, University of Southampton, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235205.
Pełny tekst źródła
50
Bakkabulindi, Geofrey. "Planning Models for Single Wire Earth Return Power Distribution Networks". Licentiate thesis, KTH, Elektriska energisystem, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-107160.
Pełny tekst źródłaStreszczenie:
The high cost of grid extension to rural areas, often characterized by scattered communities with low load densities, requires the use of low cost electrification technologies to ensure economic viability. In Single Wire Earth Return (SWER) power distribution networks, the earth itself forms the current return path of the single phase system leading to significant cost savings on conductors, poles and poletop hardware compared to conventional systems. However, challenges exist in SWER with regard to earthing and safety as well as the dependence on earth conductivity to supply consumer loads. This work presents models for the optimal planning of SWER distribution networks. The earth return path is modeled as a conductor based on the Carson line model taking into consideration specific ground properties of the considered location. A load flow algorithm for radial SWER networks is subsequently formulated whereby both overhead line and ground voltages and currents are determined. First, heuristic planning models are developed based on the SWER load flow model. The objective of the heuristic models is to determine the optimum feeder configuration and overhead conductor subject to SWER load flow constraints and load growth over several time periods. Whereas the resulting solutions are good, they may not necessarily be globally optimum. Optimization models are then developed using mixed integer non-linear programming (MINLP) with the aim of obtaining global solutions to the SWER network planning problem. Since the MINLP formulations are limited to the accurate analysis of limited size networks, considerations and approximations for the analysis of larger networks are presented. The developed models are applied to a case study in Uganda to test their practical application. In addition, comparative studies are done to determine how the proposed optimization models compare with previous distribution planning models. The numerical analysis includes the impact of deterministic distributed generation on the SWER planning problem. Results showed consistent performance of the proposed heuristic and optimization models, which also compared well with conventional models. The optimization models gave more cost-effective solutions to the SWER planning problem than the heuristic models. However, the former models had higher computational cost than the latter. The inclusion of distributed generation allowed for cheaper network solutions to be obtained. The models are applicable to the planning of Single Wire Earth Return networks for isolated mini-grids, grid-extension to previously un-electrified rural areas as well as the upgrade of SWER feeders in existing installations.QC 20121207
Sustainable Technological Development in the Lake Victoria Region