Dissertations / Theses on the topic 'Development of local power systems'
To see the other types of publications on this topic, follow the link: Development of local power systems.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Development of local power systems.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Tinarwo, Loyd. "Development of methodologies for deploying and implementing local & medium area broadband PLC networks in office and residential electric grids." Thesis, University of Fort Hare, 2008. http://hdl.handle.net/10353/83.
Full textAbstract:
The use of electrical networks for telecommunications has a long history. It has been known since the beginning of the twentieth century [Ahola03]. The idea of using electrical networks for broadband communications arose in the 1990s [Hrasnica et al 04]. Recent and growing research interest has indicated that PowerLine Communications (PLC) is the threshold for achieving broadband delivery particularly in very dispersed and low teledensity areas. Currently, there are numerous PLC trials and commercial deployments underway inside and outside South Africa. Nevertheless, these PLC deployments are very isolated, done without clear methodology and performance remains bound to the physical layout of the electrical network. Because of that high bandwidth broadband PLC systems are prone to poor performance and this in turn limits the acceptance and deployment of this emerging alternative broadband technology. Though, PLC technical challenges are being addressed, there has been little analysis and research work that is focused on the “Development of Methodologies for Deploying and Implementing Local & Medium Area Broadband Power Line in Residential and Office Electric Grids” that would lead to broadband PLC being adopted and be of greater use to non-broadband communities of South Africa. PLC is a term describing several different systems using electrical grid distribution wires for simultaneous distribution of data by superimposing an analog signal [Hrasnica et al 04]. The research proposed and presented broadband PLC methodologies for typical medium voltage and local voltage PLC networks. These methodologieswere implemented and experimented with in configurations which closely mirrored residential and office settings through laboratory and multibuilding experiments using commercial 2nd Generation Mitsubishi Electric PLC technology. Research results presented not only serve to provide insight into broadband PLC but also how it handled broadband applications (communications), competed and compared with other technologies such as Ethernet LAN. In combination with networking communication theories, the research explored and analyzed the extent of PLC in providing broadband communication to residential and office electric grids at the University Fort Hare, Computer Science Department.
2
Hermanus, Lauren. "Local governments' changing power in South Africa's energy system: reshaping the regulatory space for renewable energy, from the bottom up." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/25323.
Full textAbstract:
In 1994, South Africa's post-apartheid government inherited a highly-centralised energy sector, in which all aspects including planning, procurement, generation, distribution, pricing, and management were determined through top-down institutional arrangements and investments, centred around Eskom. In 2016, however, following rounds of energy sector reform, and the successful implementation of the Renewable Energy Independent Power Producers Procurement Programme (REIPPPP), this centralised configuration of power showed signs of disruption. Municipalities began to ambitiously redefine their role by building on opportunities related to renewable energy, resulting in an emergent challenge to centralised energy policy and planning. This dissertation sought to explore how this contestation took shape and to explain how seemingly ad hoc actions have created new possibilities, as well as new regulatory frameworks, by municipalities for municipalities. To achieve this, an analysis of the evolution of decentralised renewable energy generation in South Africa between 2008, when it first began, and 2016, was undertaken, applying the method of process tracing to two case studies. In order to contextualise these bottom-up processes within the national political economy of energy, process tracing was also applied in a high-level analysis of countervailing movements that consolidate centralised energy planning and procurement during the same period, with a particular focus on national plans to undertake massive investments in nuclear energy. It was found that municipalities' bottom-up actions have positioned them to drive renewable energy in such a way that seriously challenges the historical configuration of power that has determined South Africa's energy future up to now.
3
Беспала, Наталія Григорівна. "Прогнозування розвитку локальної енергетичної системи енергоспоживання на основі техноценологічного підходу." Master's thesis, КПІ ім. Ігоря Сікорського, 2019. https://ela.kpi.ua/handle/123456789/32152.
Full textAbstract:
Актуальність теми: напрямки розвитку ЛЕС повинні базуватися на розвитку мережевої інфраструктури і генеруючих потужностей, забезпеченні задоволення довгострокового і середньострокового попиту на електричну енергію і потужність, формуванні стабільних і сприятливих умов для залучення інвестицій в модернізацію мереж. Прогнозування майбутніх показників електроспоживання дозволяє досягти найважливішого принципу формування надійної та ефективної роботи ЛЕС - забезпечення чіткого системного балансу виробництва та споживання енергії. Тому дослідження прогнозування розвитку ЛЕС є досить актуальним під час змін, що відбуваються у країні.
Мета дослідження: застосування і адаптація техноценологічного методу для прогнозування обсягів енергоспоживання локальної енергетичної системи. Формування програми модернізації локальної енергетичної системи енергоспоживання.
Задачі дослідження:
Для досягнення мети було сформульовано такі задачі:
- Аналіз напрямків розвитку сучасних локальних та регіональних енергетичних систем;
- Визначення технічної політики модернізації ЛЕС;
- Прогнозування енергоспоживання ЛЕС за допомогою техноценологіч-ного підходу;
- Використання техноценологічного аналізу як розвиток ЛЕС за рахунок використання нового обладнання;
- Аналіз заміщення традиційної генерації на гнучку в ЛЕС;
- Формування програми модернізації системи енергоспоживання на основі техноценологічного підходу;
- Складення програми модернізації системи прогнозування щодо розвитку ЛЕС, як пропозицію для обленерго.
Об’єкт дослідження: режими функціонування локальної енергетичної системи, методи керування системою для підвищення її енергетичної ефективності.
Предмет дослідження: процеси енергоспоживання локальної енергетичної системи.
Наукова новизна одержаних результатів: на основі проведеного аналізу прогнозування розвитку ЛЕС було розроблено програму модернізації системи енергоспоживання на основі техноценологічного підходу, що дало змогу, використати програму модернізації системи як пропозицію для обленерго. На основі проведеного техноценологічного аналізу було побудовано ранговий аналіз енергоспоживання ЛЕС, проведено інтервальне оцінювання результатів аналізу та виявлено елементи ЛЕС з аномальним енергоспоживанням, що дало змогу оцінити потенціал впровадження гнучкої генерації з точки розвитку ЛЕС.
Практичне значення роботи: робота має практичне значення при проведенні реконструкції та модернізації ЛЕС використовуючи програму модернізації системи енергоспоживання на основі техноценологічного підходу.Actuality of theme. The directions of the development of forestry should be based on the development of network infrastructure and generating capacity, ensuring the satisfaction of long-term and medium-term demand for electricity and power, the formation of stable and favorable conditions for attracting investments in modernization of networks. Forecasting of future indicators of electric consumption allows achieving the most important principle of forming a reliable and effective forestry work - providing a clear system balance of production and energy consumption. Therefore, research on forestry development forecasting is very relevant during the changes taking place in the country. The purpose of the study is the application and adaptation of the technocenological method for forecasting the volumes of energy consumption of the local power system. Formation of the program of modernization of the local power system of energy consumption. Tasks of research To achieve the goal, the following tasks were formulated: - Analysis of directions of development of modern local and regional power systems; - Definition of the technical policy of forestry modernization; - Forecasting of forest energy consumption using technocenological approach; - Use of technocenological analysis as forest development through the use of new equipment; - Analysis of replacement of traditional generation to flexible in forest; - Formation of the program of modernization of the system of energy consumption on the basis of technocenological approach; - Completion of the program of modernization of the forecast system for the development of forest, as a proposal for oblenergo. Object of research: operating modes of the local power system, methods of management of the system to increase its energy efficiency. Subject of research: processes of energy consumption of the local power system. Scientific novelty of the obtained results - On the basis of the analysis of forecasting the development of forestry, a program for modernizing the energy consumption system was developed on the basis of the technocenological approach, which made it possible to use the program of modernization of the system as a proposal for the oblenergo. - On the basis of the technocenological analysis, a rank analysis of forest energy consumption was constructed, an interval estimation of the results of the analysis was carried out, and elements of forest with abnormal energy consumption were identified, which made it possible to estimate the potential of introducing a flexible generation from the point of development of forest. The practical significance of the results The work is of practical importance during the reconstruction and modernization of the forest using the program of modernization of the system of energy consumption on the basis of the technocenological approach.
4
Ala-Mutka, Jonatan. "Powering Africa by Empowering its People : An Action Research study at a Zambian microgrid company building local capacity to reach large scale viability." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261596.
Full textAbstract:
Despite recent advances in the global electrification rates, increasing from 76% in 1990 to 85% in 2012, the United Nations goal of universal access to electricity by 2030 is still far from achieved, with an estimated 1.1 billion people still without access to electricity. Over half of these live in Sub-Saharan Africa, with a majority in rural areas and extreme poverty. Major challenges are inert with the current electrification path of centralized grid extension, leaving these people without power in decades to come. Microgrids, a decentralized power system consisting of solar power generation, energy storage and distribution technology, has been hailed as the only option to provide life improving and productivity inducing power for rural communities in Africa. However, despite recent hype and development in the sector, the diffusion of microgrids is still incremental due to a lack of viable large-scale operation, required for profitability. This is explained by targeting customers in remote rural areas with low ability to pay, and the task of delivering expensive technology and complex operations needed to manage and operate the grids. No industry blueprint or research on how to operate microgrids at scale or profitably exists. This thesis explores one blueprint, with the promise to increase profitability and allow for a more sustainable scaling. Local Capacity building is a decentralized approach by developing capacity directly in the local communities, through recruiting, skills development and training of people to be employed to operate and manage their local microgrids. The results consist of a framework outlining what local capacity building is, through research propositions that define the key components capturing the complete system of local capacity building is for scaling a microgrid business, along with the challenges and opportunities associated with scaling a business using local capacity building. It has been developed iteratively by application of an action research approach conducted on a small-scale Zambian Microgrid company facing radical growth. The researcher was immersed in the context, at the heart of this change, and in a participatory and interventionist fashion turning every stone to explore what local capacity building is, resulting in a robust study anchored in the field. Because of the contextually embedded nature of the data, this also means that the results are local. It is up to the reader to assess the applicability of the results in another context. The extensive results span multiple areas of the business, capturing the complexity of local capacity building, and contribute to knowledge on a holistic level on what local capacity building is. This blueprint was deemed viable to further develop in the small-scale Zambian microgrid company, specifically because of its potential to lower operating expenses and offer a more sustainable way to scale, and in extension diffuse microgrids in Africa.Trots en positiv utveckling i tillgång till el globalt, ökandes från 76% år 1990, till 85% år 2012, så är Förenta Nationernas mål om universell tillgång till el till år 2030, långt ifrån att bli uppfyllt. 1.1 miljarder människor estimeras vara utan tillgång till el globalt, där över hälften av dessa bor i Sub-Saharanska Afrika, med majoriteten levandes på landsbygden och i extrem fattigdom. Stora utmaningar finns med innevarande elektrifierings strategin, som handlar om centraliserad elproduktion och distribution genom ett centralt elnät, detta kommer att lämna dessa människor utan el under lång tid framöver. Mikronät, ett decentraliserat energisystem, som kan producera och distribuera el, har lyfts fram som det bästa alternativet för att försörja livsförbättrande och produktivitetsökande elektricitet för samhällen på landsbygden i Afrika. Dock, trots nylig hype och utveckling i mikronät sektorn, så är spridningen av mikronät fortfarande inkrementell, beroende av en brist på genomförbarheten av att driva mikronät verksamheten i stor skala, vilket krävs för lönsamhet. Detta förklaras av den fundamentala utmaningen i att inrikta sig mot kunder i avlägsna områden, med en låg förmåga att betala, kombinerat med leveransen av dyr teknologi, och de komplex operativa strukturerna som krävs. Det finns ingen forskning eller blåkopia i industrin som visar hur man skulle kunna bedriva mikronäts verksamhets i stor skala, eller på ett lönsamt vis. Denna forskning undersöker en möjlig sådan blåkopia, med löftet att öka lönsamheten och möjliggöra en mer hållbar spridning. Utveckling av lokal kapacitet, är ett decentraliserat tillvägagångssätt för att utveckla kapacitet direkt i dessa avlägsna samhällen, genom rekrytering, färdighetsutveckling och utbildning av människor för att bli anställda för att sköta deras lokala mikronät. Resultaten i studien består av ett ramverk som visar vad utveckling av lokal kapacitet innebär, genom forskningsförslag som definierar vilka nyckelkomponenter som krävs för att skala upp en mikronäts verksamhet, tillsammans med utmaningar och möjligheter för att göra detta. Ramverket har utvecklats iterativt genom applicering av Action Research, utförd i ett småskaligt mikronät företag i Zambia som står inför en radikal expansion. Forskaren var fördjupad i företagskontexten, i hjärtat av förändringen, och på ett ingripande och deltagande sätt vänt på varenda sten för att utforska vad utveckling av lokal kapacitet är. Detta resulterade i en robust studie, förankrad i verkligheten. På grund av den kontextuellt inbäddade naturen av datan, så betyder detta även att resultaten är lokala. Det är upp till läsaren att bedöma till vilken grad resultaten kan appliceras i en annan kontext. De omfattande resultaten spänner över många olika områden i företaget, och lyckas fånga komplexiteten i vad utveckling av lokal kapacitet är. Blåkopian som utvecklades, bedömdes värdefull att utveckla vidare i företaget där studien gjorde, specifikt för dess potential att minska de operativa kostnaderna och erbjuda ett mer hållbart sätt att skala verksamheten, och i förlängningen, erbjuda ett mer hållbart sätt att sprida tillgång till el i Afrika.
5
Olivella, Rosell Pol. "Local electricity markets design and operation in distribution power systems." Doctoral thesis, Universitat Politècnica de Catalunya, 2020. http://hdl.handle.net/10803/669803.
Full textAbstract:
In the context of distributed generation growth, local grids could face operational issues. In that sense, smart grid deployment will give information to local grid operators about grid status at medium and low voltage levels for taking operational decisions on daily basis. This thesis presents local markets as a potential solution to avoid local grid congestions and over-costs. They mainly increase the negotiation power of end-users with distributed energy resources and allow activation of flexibility at local level.
First of all, this thesis analyses electric vehicles as a potential challenge for distribution grids and electricity markets in case of uncontrolled charging as it could cause consumption peaks. At the same time, electric vehicles could be part of the solution thanks to their capability of shifting forward their consumption. The first solution presented in this thesis is a building level electric vehicle management algorithm in order to reduce energy cost and consumption peaks.
However, local grid operators need a solution to deal with aggregated level problems like high demand or high generation periods. Such kind of problems vary over time and place, and they could be difficult to integrate in regular grid tariffs. Therefore, the present thesis provides two local market designs for these problems. The first local market presented is designed for taking advantage of renewable energy producers before and after the whole-sale day-ahead market without threatening distribution grids and increasing the local social welfare. However, this market implies significant regulatory changes because the local market operator should take sorne of the current local grid operator regulated activities.
Therefore, this thesis presents a second market design for managing portfolios of consumers, producers and prosumers, and it could be operated by retailers, balance responsible parties or aggregators for flexibility provision without regulatory issues. The work includes a description of roles, contracts and interactions of such local flexibility market, and three optimization algorithms depending on the application, complexity and portfolio scale. The first algorithm assumes limited information about each site, the second one includes such information but presents potential scalability limitations, and the last algorithm is based on a decomposition method to optimise the aggregator portfolio in a distributed way reducing the computational burden and time.En el context d'expansió de generadors d'electricitat renovable i distribuïda, les xarxes de distribució podrien presentar problemes d'operació. A més a més, en un context de desplegament de la xarxa elèctrica intel·ligent, les companyies distribuïdores tindran un millor coneixement de l'estat de la xarxa per prendre decisions d'operació en el dia a dia tant a nivell de mitja com en baixa tensió. Els mercats locals constitueixen una possible solució per a la resolució de congestions a les xarxes de distribució d'electricitat i reduir els sobre costos del sistema elèctric. Aquests mercats també permetrien incrementar el poder de negociació dels consumidors d'electricitat a petita escala amb capacitat de flexibilitat. Primerament s'analitza el potencial perill que poden suposar els vehicles elèctrics per a les xarxes de distribució en cas de no haver-hi gestió intel·ligent dels processos de carrega ja que podrien aparèixer nous pics de consum. Alhora, els vehicles elèctrics podrien ser part de la solució desplaçant el seu consum a la nit. El present treball inclou un algorisme de gestió de vehicles elèctrics a nivell d'edifici per a reduir el cost d'electricitat i els pics de consum. No obstant, les companyies distribuïdores necessiten una solució per als problemes de la xarxa que podrien ser diferents segons la zona o l'època de l'any. Es per això que aquest treball inclou dues propostes de mercat local per a aquests problemes. El primer mercat local esta dissenyat per a aprofitar l'avantatge dels productors d'energia renovable abans i després del mercat diari majorista sense comprometre l'operació de la xarxa de distribució. Tot i aixó, aquesta proposta de mercat local requeriria diversos canvis en matèria de regulació ja que l'operador del mercat local hauria de prendre algunes de les actuals responsabilitats de les companyies distribuïdores. Seguidament, la tesi presenta un segon mercat local per gestionar una cartera de consumidors, productors i prosumidors, com una activitat més dins de les activitats de les companyies comercialitzadores o agregadors de flexibilitat. El present document inclou una descripció dels rols, contractes i interaccions, i tres algorismes d'optimització des del més simple fins al més complex. El primer assumeix una limitació en la informació disponible de cada membre de la cartera, el segon inclou més informació però presenta limitacions d'escalabilitat, i finalment el tercer presenta un algorisme de descomposició per optimitzar la flexibilitat de manera distribuïda i així reduir el temps de computació i la complexitat de càlcul.
6
Ehlers, Bodo. "Development of high power diode laser systems /." Aachen : Shaker, 2005. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=014901694&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Full text
7
Zhu, Lei. "Advanced local prediction and its applications in power and energy systems." Thesis, University of Liverpool, 2014. http://livrepository.liverpool.ac.uk/2007714/.
Full textAbstract:
Due to the global energy crisis and environmental concerns, the development of sustainable energy is considered by more and more countries. In order to make this target, energy demand management is significantly necessary in which forecasting the energy demand is the starting point. The accurate prediction of energy demand could help the energy sectors to make these operation decisions and policy properly. A novel approach, which is the support vector regression based local predictor with false neighbor filtered (FNF-SVRLP), is proposed. This method is an amelioration of the support vector regression based local predictor (SVRLP). SVRLP is a powerful prediction method which employs phase reconstruction algorithms, such as the correlation dimension and mutual information methods used in time series analysis for data preprocessing. Compared with the global prediction method, in a local prediction method, each predicting point has its own model constructed based on its nearest neighbors (NNs) reconstructed from the time series, and the fitness of NNs would mainly affect the model performance. However, it has been found that NNs may contain a class of false neighbors (FNs) which would decrease the fitting accuracy dramatically and lead to a poorer forecasting performance. Therefore, a new false neighbor filter is proposed to remove those false neighbors and keep the optimal nearest neighbors. Then, the FNF-SVRLP is proposed. Wind power is one of the most popular renewable energy. The increasing penetration of wind power into the electric power grid accompanied with a series of challenges. Due to the uncertain and variable nature of wind resources, the output power of wind farms is hard to control, which could lead to the instability of the power grid operation and the unreliability of electricity supplies. In order to slove this problem, the FNF-SVRLP based short-term wind power perdition model is presented. Through the comparison with the SVRLP based short-term wind power perdition and ARMA based short-term wind power perdition, it is found that the FNF-SVRLP based short-term wind power perdition model is much more accurate than the others. Due to the fact that natural gas is cleanest burning of all fossil fuel, it can be considered as an important adjunct to renewable energy sources such as wind or solar, as well as a bridge to the new energy economy. Different from the wind power, the customer consumption behavior could effect the natural gas demand. Therefore, the customer behavior based ``Advanced Model" with FNF-SVRLP is presented to undertake the natural gas prediction. The proposed FNF-SVRLP natural gas model is compared with the SVRLP and autoregressive moving average (ARMA) to show its superiority. In addition, a web sever based online natural gas demand perdition system has been set up to help the National Grid to obtain the accurate daily natural gas demand perdition easily and timely. It is found that the most kinds of energy demand data are non-stationary, the internal regularity between predicting point and its nearest-neighbors are much more complex than the stationary dataset. In order to help the local predictor to capture the internal regularity between predicting point and its nearest-neighbors more accurately, the morphological filter is proposed. the morphological filter is applied to decompose the non-stationary dataset into several subsequences, ranked form the low frequency subsequence to the high frequency subsequence. Through this way, the local predictor could capture the non-stationary dataset more accurate, and improve the final performance of prediction. The morphological filter is applied to decompose the non-stationary into several subsequences, ranked form the low frequency subsequence to the high frequency subsequence. Through this way, the local predictor could capture the non-stationary dataset more accurate, and improve the final performance of prediction. Moveover, an novel calculation method of structure element (SE) is introduced. Different form the conventional SE, this novel approach can optimize the scale and shape of SE to match the original signal. After that, a novel algorithm, which is mathematical morphology based local prediction with support vector regression (SVRLP-MM) is proposed. The real-world wind speed data has been used to evaluate the performance of SVRLP-MM. The final results presented demonstrate that SVRLP-MM based wind speed prediction model can achieve a higher prediction accuracy than the SVRLP based model and ARMA model based model by using the same real-world wind speed data.
8
Blanchard, Tina-Louise. "A Systems Engineering Reference Model for Fuel Cell Power Systems Development." Cleveland State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=csu1322713336.
Full text
9
Huang, Yan. "FAST RECONFIGURATION ALGORITHM DEVELOPMENT FOR SHIPBOARD POWER SYSTEMS." MSSTATE, 2005. http://sun.library.msstate.edu/ETD-db/theses/available/etd-11012005-151018/.
Full textAbstract:
Today?s protection schemes for shipboard applications, such as the zone-based differential protection, are efficient, fast, and reliable for fault detection. However, these protection schemes do not consider the system stability or power balance problems that occur with fault isolation and the system reconfiguration. This thesis focuses on developing the extended protection function including the fast reconfiguration function that intends to maintain the power balance of the unfaulted subsystem. Graph theory is utilized to represent the shipboard power system topology in matrices, and matrix operations are developed to represent the corresponding power system topology change and evaluate the outcome of the fault. Intelligent search algorithms are implemented to find the possible system configuration after fault isolation with balanced power generation and load through merging possible connected systems and priority-based load shedding. The algorithms are successfully implemented in MATLAB m-files and tested on various shipboard power system configurations and fault scenarios.
10
Al-Khaykan, Ameer. "Controller design methodology for sustainable local energy systems." Thesis, University of Chester, 2018. http://hdl.handle.net/10034/621613.
Full textAbstract:
Commercial Buildings and complexes are no longer just national heat and power network energy loads, but they are becoming part of a smarter grid by including their own dedicated local heat and power generation. They do this by utilising both heat and power networks/micro-grids. A building integrated approach of Combined Heat and Power (CHP) generation with photovoltaic power generation (PV) abbreviated as CHPV is emerging as a complementary energy supply solution to conventional (i.e. national grid based) gas and electricity grid supplies in the design of sustainable commercial buildings and communities. The merits for the building user/owner of this approach are: to reduce life time energy running costs; reduce carbon emissions to contribute to UK’s 2020/2030 climate change targets; and provide a more flexible and controllable local energy system to act as a dynamic supply and/or load to the central grid infrastructure. The energy efficiency and carbon dioxide (CO2) reductions achievable by CHP systems are well documented. The merits claimed by these solutions are predicated on the ability of these systems being able to satisfy: perfect matching of heat and power supply and demand; ability at all times to maintain high quality power supply; and to be able to operate with these constraints in a highly dynamic and unpredictable heat and power demand situation. Any circumstance resulting in failure to guarantee power quality or matching of supply and demand will result in a degradation of the achievable energy efficiency and CO2 reduction. CHP based local energy systems cannot rely on large scale diversity of demand to create a relatively easy approach to supply and demand matching (i.e. as in the case of large centralised power grid infrastructures). The diversity of demand in a local energy system is both much greater than the centralised system and is also specific to the local system. It is therefore essential that these systems have robust and high performance control systems to ensure supply and demand matching and high power quality can be achieved at all times. Ideally this same control system should be able to make best use of local energy system energy storage to enable it to be used as a flexible, highly responsive energy supply and/or demand for the centralised infrastructure. In this thesis, a comprehensive literature survey has identified that there is no scientific and rigorous method to assess the controllability or the design of control systems for these local energy systems. Thus, the main challenge of the work described in this thesis is that of a controller design method and modelling approach for CHP based local energy systems. Specifically, the main research challenge for the controller design and modelling methodology was to provide an accurate and stable system performance to deliver a reliable tracking of power drawn/supplied to the centralised infrastructure whilst tracking the require thermal comfort in the local energy systems buildings. In the thesis, the CHPV system has been used as a case study. A CHPV based solution provides all the benefits of CHP combined with the near zero carbon building/local network integrated PV power generation. CHPV needs to be designed to provide energy for the local buildings’ heating, dynamic ventilating system and air-conditioning (HVAC) facilities as well as all electrical power demands. The thesis also presents in addition to the controller design and modelling methodology a novel CHPV system design topology for robust, reliable and high-performance control of building temperatures and energy supply from the local energy system. The advanced control system solution aims to achieve desired building temperatures using thermostatic control whilst simultaneously tracking a specified national grid power demand profile. The theory is innovative as it provides a stability criterion as well as guarantees to track a specified dynamic grid connection demand profile. This research also presents: design a dynamic MATLAB simulation model for a 5-building zone commercial building to show the efficacy of the novel control strategy in terms of: delivering accurate thermal comfort and power supply; reducing the amount of CO2 emissions by the entire energy system; reducing running costs verses national rid/conventional approaches. The model was developed by inspecting the functional needs of 3 local energy system case studies which are also described in the thesis. The CHPV system is combined with supplementary gas boiler for additional heating to guarantee simultaneous tracking of all the zones thermal comfort requirements whilst simultaneously tracking a specified national grid power demand using a Photovoltaics array to supply the system with renewable energy to reduce amount of CO2 emission. The local energy system in this research can operate in any of three modes (Exporting, Importing, Island). The emphasise of the thesis modelling method has been verified to be applicable to a wide range of case studies described in the thesis chapter 3. This modelling framework is the platform for creating a generic controlled design methodology that can be applied to all these case studies and beyond, including Local Energy System (LES) in hotter climates that require a cooling network using absorption chillers. In the thesis in chapter 4 this controller design methodology using the modelling framework is applied to just one case study of Copperas Hill. Local energy systems face two types of challenges: technical and nontechnical (such as energy economics and legislation). This thesis concentrates solely on the main technical challenges of a local energy system that has been identified as a gap in knowledge in the literature survey. The gap identified is the need for a controller design methodology to allow high performance and safe integration of the local energy system with the national grid infrastructure and locally installed renewables. This integration requires the system to be able to operate at high performance and safely in all different modes of operation and manage effectively the multi-vector energy supply system (e.g. simultaneous supply of heat and power from a single system).
11
Zhang, Meishenglan. "Power-Aware Software Development For EMCA DSP." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215711.
Full textAbstract:
The advent of FinFET technology necessitates a shift towards early dynamic power awareness, not only for ASIC block designers but also for software engineers that develop code for those blocks. CMOS dynamic power is typically reduced by optimizing the RTL models in terms of switching activity and clock gating efficiency. There is not much to be done after a model is committed. Programmable blocks though, like the Phoenix 4 Digital Signal Processor(EMCA Ericsson Multi Core Architecture), can have a “second chance” for low power even after silicon is produced by efficient use of the software source code in order to impact the dynamic power metrics. This requires a "full-stack" of power awareness all the way from the DSP hardware model up to the software development IDE. This Thesis work aims at two goals. The first goal is to realize a prototype, encapsulated flow for the DSP software developers which connects software IDE entry point to the low level, complex hardware power analysis tools. The second goal is to demonstrate how software can be used as an auxiliary knob to exploit potential tradeoffs in order to improve the DSP's dynamic power metrics. This hypothesis is tested by rescheduling operations on the DSP's resources either manually or implicitly through the compiler. Moreover, a method to align and compare algorithms, when it is possible to tradeoff performance for power, is devised and the estimation results are compared against real silicon measurements. The results show that the developed analysis flow is reliable and very efficient for the given purpose, even for people who have limited knowledge about low level hardware to facilitate quick power exploration and profiling. This is mainly realized by a unique feature that associates specific lines in the source code with the toggling behavior of the hardware model while execution. Based on that, the tradeoffs between power and performance for several testcases are demonstrated at both the assembly and C levels with good correlation versus silicon. Overall, this work's outcome hints that the compiler and software teams have many options to consider in order to optimize dynamic power for products already in the field.
12
Ehlers, Bodo [Verfasser]. "Development of High Power Diode Laser Systems / Bodo Ehlers." Aachen : Shaker, 2005. http://d-nb.info/1186589256/34.
Full text
13
Gorbuntsova, Tatiana. "Spatiality of power surrounding "the Nenets'" involvement in local tourism industry development." Thesis, Sheffield Hallam University, 2016. http://shura.shu.ac.uk/15207/.
Full textAbstract:
The importance of power structure analysis in tourism studies is appreciated by academic scholars based on the fact that the tourism industry is a capitalist activity concerned with wealth production, accumulation and distribution. This is the power structure that serves to reproduce and condition different modes of tourism industry development and, as a consequence, diverse outcomes for the local economy in general and its players specifically. However, under the influence of Karl Marx, theorists using critical approaches to research power have tended to focus on issues around the equality of power relationships between actors or stakeholders. In doing so, it may be argued that what is missing are the diverse geographies of power and, in particular, the inherently spatial nature of power, including the involvement of social relations in both space and power (Lefebvre, 1976; 1991). In order to address this, the present study focuses on the exploration of the spatiality of power that surrounds tourism industry development. A conceptual framework, based on the application of Lefebvre’s (1991) concepts supplemented by Gaventa’s (2004) ‘power cube’, placed in the broader context of Marx’ political economy and ‘Historical Materialism’, has been developed. The case study locality is in a country with a non-colonial past, being in transition from socialism to capitalism, with the tourism industry at an early stage of its development. Of core interest to the study is the spatiality of power which frames local tourism industry development, the relationships between the indigenous reindeer herders, “the Nenets”, local non-indigenous tour operators, indigenous travel agencies and the government in Yamal in the Yamal-Nenets Autonomous Okrug (YNAO) of the Russian Federation. Based on the aim to access the respondents’ subjective comprehension and evaluation of spatiality of power, the research is positioned in neo-empiricism and uses qualitative methods of data collection and analysis. The major theoretical findings confirm Marx’ theory of ‘Historical Materialism’. In these terms, they support Marx’ (1974), Lefebvre’s (1991), Webster et. al.’s (2001) and O’Neil’s (2007) beliefs that, formed under the historical conditions, political economy regime influences “The Production of Space” and the associated spatiality of power (Lefebvre, 1991). The findings also support the conception of social space theorised by Lefebvre (1991) in terms of the interwoven nature of mental and material constructions of space. In this, the findings do not support Karl Marx and Georg Hegel, as well as their followers amongst tourism scholars, prioritizing material constructions of space over mental (for example, regulationists, comparative and Marxist political economists) or vice versa (for example, advocates of cultural political economy and alternative/post-structural political economy). Additional findings made do not support the existence of ‘false consciousness’ amongst the representatives from “the Nenets”, indigenous travel agencies and non-indigenous tour operators; the relationships of dependency between “the Nenets”, local non-indigenous tour operators and indigenous travel agencies based on the possession by “the Nenets” the ‘means of production’; and the existence of power everywhere promoted by Foucault. For future studies on spatiality of power it would be worthwhile to include the ‘expressions of power’ (‘power within’, ‘power to’ and ‘power with’) offered by VeneKlasen & Miller (2002) to complement Lefebvre’s (1991) ‘spatial triad’ and Gaventa’s (2006) ‘power cube’.
14
Winship, Michele Lynn. "Ohio's local professional development committees : politics and power among teachers and administrators /." The Ohio State University, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488192447427811.
Full text
15
Amoda, Oluwaseun Adeyemi. "DEVELOPMENT OF AN ADAPTIVE PROTECTION SCHEME FOR SHIPBOARD POWER SYSTEMS." MSSTATE, 2007. http://sun.library.msstate.edu/ETD-db/theses/available/etd-06062007-133738/.
Full textAbstract:
Reconfiguration is needed to meet the fight-through and survivability requirements of a shipboard power system. Reconfiguration involves the re-arrangement of power system topology through the opening and switching of breakers, and adjusting of total generators and load values. When the power system is reconfigured, the protection system needs to be attuned to the new power system state. This thesis focuses on developing an adaptive protection scheme for shipboard power systems that will automatically update relay settings after changes in power system topology and operational state. The developed adaptive protection scheme employs four main algorithms to achieve its goal. A topology-recognition algorithm uses the statuses (open/close) of breakers to determine the topological-configuration of the system. A power-flow and a fault-analysis algorithm are used to determine the system?s normal and fault currents, respectively. A protection-setting algorithm is used to determine and set the operating parameters of all the relays in the system. The scheme was implemented in MATLAB m-files and tested on various configurations of a notional shipboard power system. The tests results were verified in CAPE.
16
Buse, Jonathan. "Development of SoC-based embedded systems for power system automation." Thesis, University of Liverpool, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.539495.
Full text
17
He, Fei. "The development of high power fibre chirped pulse amplification systems." Thesis, University of Southampton, 2009. https://eprints.soton.ac.uk/70913/.
Full textAbstract:
With its broad gain bandwidth and high optical conversion efficiency, ytterbium (Yb)-doped silica fiber represents an attractive medium for the generation and amplification of ultrashort optical pulses. Research interest in Yb-doped fiber chirped pulse amplifier (CPA) systems first appeared in the late 1990s. However, the potential advantages and capabilities of Yb-doped fiber CPA systems were not fully studied during the early research. Further scaling of both the average power and the pulse energy have now become possible with the development of several key technologies that are associated with Yb-doped fiber CPA systems. Finally, the development of a novel fiber CPA system operating with strong selfphase-modulation (SPM) is described, which applied adaptive shaping of the spectral phase of the input pulses. The pre-compensation of both SPM induced phase distortion at high energies, and residual dispersion from mismatched stretcher/compressor technologies at low energies are investigated
18
Legg, Thomas. "Development of high power fibre amplifier components, systems and applications." Thesis, University of Strathclyde, 2012. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=25959.
Full textAbstract:
This thesis contains two projects - the development of a Raman fibre amplifier system for gas sensing and the development of a fibre-in beam-out isolator for use with fibre lasers. The first project developed a fibre Raman amplifier which amplified a 10mW narrow linewidth DFB laser at 1651nm to an output power of over 2W. To achieve this high output power from a narrow linewidth Raman amplifier mechanisms to suppress stimulated Brillouin scattering had to be employed. This amplifier system was packaged into a portable 19” rack enclosure and used to demonstrate remote, single-end, tuneable diode laser spectroscopy of methane. The packaged system detected methane concentrations of 100ppm.m at over 100m during challenging field trials. Extrapolation of lab based measurements to longer distances predicts an ultimate sensitivity of the system of 100ppm.m at greater than 200m. The second project developed a Faraday isolator to be used at the output of industrial fibre lasers. The isolator had an isolation of greater than 30dB, an insertion loss of less than 0.5dB and a return loss of greater than 50dB. The isolator used a dual Faraday rotator design with a half wave plate between the rotators to compensate for thermal stress induced birefringence. Using this approach the isolation was shown to be constant to greater than 60W. The isolator was also compensated for thermal lensing by balancing the positive thermal lens produced in the Faraday rotator with a negative thermal lens in a DKDP crystal. This reduced the thermal lens of the isolator from ~9 Rayleigh length per kW intrinsic to below 2 Rayleigh lengths per kW.
19
Zou, Xiaolan. "Frequency and Damping Characteristics of Generators in Power Systems." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/81937.
Full textAbstract:
A power system stability is essential for maintaining the power system oscillation frequency within a small and acceptable interval around its nominal frequency. Hence, it is necessary to study and control the frequency for stable operation of a power system by knowing the characteristics within a power system. One approach is to understand the effectiveness of frequency and damping characteristics of generators in power systems. Hence, the simulation analysis of IEEE 118-bus power system is used for this study. The analysis includes theoretical analysis with a mathematical approach and simulation studies of swing equation to determine the characteristics of damped single-machine infinite bus, which is represented as a generator connects to a large network system with a small signal disturbance by line losses. Additionally, mathematical derivation of Prony analysis is presented in order to estimate the frequency and damping ratio of the simulation results. In the end, the results demonstrate that the frequency and damping characteristics of generators are highly dependent on the system inertia constant. Therefore, the higher inertia constant is a critical factor to ensure the system is more stable.Master of Science
20
Williams, Nathan Gordon. "The development of a local area network : a systems engineering approach /." Master's thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-03302010-020354/.
Full text
21
Horrocks, Ivan. "Exploring information systems development in English local government : a morphogenetic approach." Thesis, Open University, 2006. http://oro.open.ac.uk/54842/.
Full textAbstract:
This thesis examines the complex relationships between agency (Le. populations, organised groups,individual actors and collectivities), structure (Le. systems, institutions, roles, positions), and culture(ideas, theories, beliefs and values) in the specific context of cycles of information systems (IS)development and organisational change in English local government. Data for this analysis is drawn from a 15 month longitudinal case study of an English local authority. The morphogenetic approach - anon conflationary approach to the analysis of the agency/structure dynamic devised by Margaret Archer (1988, 1995, 1998b, 1998c, 2002) - was adopted for the research in order to avoid treating either agents or structures as largely epiphenomenal to each other. A detailed analysis of the IS environment of the case study organisation is presented. It shows how.cycles of IS development and organisational change in general were conditioned and/or shaped and transformed and/or reproduced over time by the agency/structure dynamic. The case study material also represents an example of an 'analytical history of emergence' that Archer (1995:294) proposes should result from the use of the morphogenetic approach. Detailed evidence of the causal processes, mechanisms, powers and tendencies that may operate in any IS/organisational development context is also analysed and this then forms the basis for a range of 'tendential predictions' to be made concerning the outcomes. Another outcome (of particular significance since Archer's approach to empirical research remains limited) is a valuable assessment of the utility of the morphogenetic approach when applied to the type of largely micro level case study research reported here. This assessment confirms Archer's claims for the approach's value as an instrument for the production of non conflationary practical social theory, but, in addition, a range of issues are identified which demonstrate that, 'without modification, the complexity and resulting resource intensity of the approach may well work against its more widespread adoption for this kind of social science research.
22
Earle, Jeremy. "Local Governmental Development of Alternative Food Systems in Distressed Urban Areas." ScholarWorks, 2016. https://scholarworks.waldenu.edu/dissertations/2970.
Full textAbstract:
Alternative food systems (AFS) projects are designed to address issues of environmental justice, food security and insecurity, community health disparities between the affluent and the poor, and access to healthful foods in distressed urban areas. Past research has questioned the efficacy and long-term viability of such interventions, particularly in distressed primarily Black urban areas. The purpose of this intrinsic case study (ICS) was to understand the ways in which local governmental entities collaborated with each other and with nongovernmental partners to help develop an AFS in South Florida through the creation of a market garden called the PATCH. Critical race theory was the framework for addressing the challenges associated with community health, empowerment, and socioeconomic issues pertaining to AFS. A critical case sampling strategy was employed in order to study the selected site. Transcribed data from interviews with 6 key informants, observational notes, and publicly available document searches were coded using a thematic posteriori strategy and analyzed diagrammatically. Results revealed 4 primary drivers for the effective creation of AFS including collaboration and partnerships, community empowerment, community involvement, and the leadership role of government. The concept of transcommunality played an integral role in how these primary drivers could be applied between local governmental and nongovernmental partners. Knowledge gleaned from these results can inform the development of effective community and culturally specific AFS that can help address the disparities that race and socioeconomic status play in providing access to healthful foods in South Florida, thereby creating the basis for positive social change in distressed urban areas.
23
Harris, Vandra, and vandra harris@flinders edu au. "The Development Contact Zone: Practitioner Perspectives on Culture, Power and Participation." Flinders University. Centre for Development Studies, 2006. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20060315.221724.
Full textAbstract:
This research examines the function of culture and power in Development praxis, as defined by Post-Development theory, the Participation approach to Development, and Development workers in Cambodia and the Philippines. Practitioner perspectives have been gathered by means of informal interviews conducted in Cambodia and the Philippines. The primary inquiry of this thesis is whether Development is culturally destructive, whether the current paradigm can deliver effective results, and what effect power relations have on these outcomes.
The research approaches Development as a contact zone, in which Southern Development workers function as border crossers, moving between the cultures of funders and local communities as they work to implement Development projects and programs. This affords practitioners privileged insight into the cultural negotiations of this contact, making their input critical to this inquiry. Their input is placed in the context of Post-Development theorists� assertion that Development is a culturally destructive discourse, and the proposal by other theorists that a participatory approach to Development adequately addresses Post-Development�s key concerns. Participation addresses issues of power and context in Development practice from a different perspective from the Post-Development theorists, and outlines a series of strategies designed to overcome well-recognised limitations of Development practice.
Practitioner responses are grouped into three discussions, addressing their overall perspective on Development and Participation, their attitudes to cultural change and Development�s role within that, and their experience of power in Development funding relationships. Their responses were overwhelmingly supportive of participatory approaches to Development, and advocated a stronger role for the grassroots organisations that are pivotal to the Post-Development approach. Different attitudes to cultural change were expressed by practitioners in the two countries, however they consistently named Development as a source of positive cultural change, naming this as a key aim of their work. Finally, practitioners were critical of their relationships with funding organisations, which they felt were unduly controlled by the funders.
This research concludes that participatory Development fosters cultural liberty by reinforcing collaborative cultural traits and strengthening communities to make choices about culture. While Post-Development provides important critiques of Development, its proposed alternative of turning to the grassroots is not supported by practitioners, who seek ongoing relationships with Northern organisations and individuals. In particular, practitioners desire a model of funding relationship that reflects their own practice, by conforming to the paradigm of people that underpins the participatory approach to Development.
This thesis contributes to Development debates by presenting Southern perspectives that contrast with Post-Development, and by proposing a framework that can underpin further development of funding partnerships. Furthermore, it demonstrates that practitioners believe that Development is a reinforcing factor at a time when cultures are exposed to increasingly diverse cultural influences.
24
Pape, Ida Sophia Rosenfeldt. "Decentralisation and power structures : the role of local power structures in decentralised development and instititution building in Bolivia." Thesis, SOAS, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.424379.
Full text
25
Kimm, Dennis. "Windy Business: Exploring a Local Wind Power Project in Germany." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-330950.
Full textAbstract:
The need for a sustainable energy supply is widely recognized, as formulated under goal 7 of the United Nations’ Sustainable Development Goals. Yet, on the local level problems may arise with the implementation of renewable energy systems, such as wind power. Issues around visual intrusion of the landscape, noise and shadow flicker, and concerns over wildlife protections are often in the heart of local resistance to wind power projects. The aim of this thesis is to closely examine the developments for wind power in the city of Euskirchen in Germany, including the planning and decision making processes, with regards to milestones and obstacles encountered over the last two decades. The analysis applies the methodology of a qualitative case study. Furthermore, views and opinions of involved and affected parties are collected through semi-structured interviews, and analysed through the lenses of social acceptance and public participation. Finally, from the examination of the planning and decision making processes and the discovered local attitudes towards wind energy, recommendations will be formulated to guide future wind power developments in the region.
26
Stenlund, Nilsson Ivner Jenny. "Plan and Reality : Municipal Energy Plans and Development of Local Energy Systems." Licentiate thesis, Linköping University, Linköping University, Environmental Technique and Management, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6559.
Full textAbstract:
Enligt lagen om kommunal energiplanering ska varje svensk kommun ha en energiplan för tillförsel för tillförsel och användning av energi. Huruvida energiplanering är ett bra sätt att styra det kommunala energisystemet är dock omdebatterat. Denna avhandling studerar innehåll i, och implementering av, ett antal svenska kommunala energiplaner. Energiplanernas effektivitet studeras på två nivåer: uppfyllelse av mål och visioner i planerna, samt hur detta bidrar till att uppfylla de nationella energipolitiska målen.
Forskningen baseras på tre studier: en studie av innehållet i tolv energiplaner från Östergötland, en studie av mål och visioner i sju energiplaner och hur energisystem utvecklats efter energiplanerna antagits, samt en fallstudie av Kungälvs kommun där mål och måluppfyllelse studerats mer utförligt. Innehåll och målformuleringar i energiplanerna har analyserats med avseende på miljö, effektiv energianvändning och systemnivå. Mål och måluppfyllelse har även analyserats med avseende på aktörer.
Resultaten visar på att de studerade energiplanerna har smal systemsyn och att de miljöanalyser som finns i planerna är undermåliga. Energiplaneringen har varit effektiv till viss del. Bäst måluppfyllelse har kommunerna när det gäller mål på en relativt låg systemnivå och när det är kommunen själv som äger frågan, exempelvis fjärrvärmeutbyggnad och energieffektivisering av kommunens lokaler. När det gäller utvecklingens bidrag till de nationella energipolitiska målen är resultaten varierande: användning av biobränslen har ökat avsevärt, medan självförsörjningsgraden på el bara ökat något. Bäst är utvecklingen när det gäller minskade koldioxidutsläpp.
Baserat på bristerna som upptäckts i de studerade energiplanerna och dess implementering förs en diskussion kring möjligheter att öka energiplaneringens effektivitet och vidga systemsynen. Förbättringar som diskuteras är att stärka kopplingen till fysisk planering, och att inkludera medborgarmedverkan och miljöbedömningar. Om kopplingen till energifrågor stärks i översiktlig planering och om även privata aktörer kommer till tals under planeringsprocessen, skulle detta kunna underlätta implementering av energiplanerna. Miljöbedömningar i sin tur kan bidra med en vidare systemsyn om mer relevanta mål i planerna. Slutligen föreslås att ramverket för miljöbedömning av planer och program (2001/42/EC) kan användas vid energiplanering eftersom det framhåller vikten av breda analyser, samråd med privata aktörer och miljöbedömningar.
Swedish municipalities are required to produce a municipal energy plan for energy supply and use. Whether energy planning is suitable to manage local energy systems, however, is subject to debate. This thesis explores municipal energy planning and development of local energy systems after energy plans were adopted to examine whether energy planning is effective. The effectiveness of energy planning is studied on two levels: in terms of whether goals in energy plans were implemented, and whether energy planning contributes to fulfilling national energy policy goals.
The research is based on three studies. In the first, the scope of twelve municipal energy plans from a Swedish region was assessed. In the second study, goals and visions in seven energy plans were analysed and compared to the development of the local energy systems. The third case involved Kungälv municipality, where the implementation of goals in its energy plan was studied more thoroughly. Scopes and goals in the energy plans were analysed from three perspectives: the environment, energy efficiency and the systems level. Goals and development were also analysed from an actor’s perspective.
The results show that the scopes of the studied energy plans have narrow systems boundaries, and that the environmental analyses presented in the plans are very basic. Energy planning was found to have been fairly effective in terms of fulfilment of goals in energy plans. Most positive developments are for goals on a relatively low systems level when the local authority owns the issue, for example district heating expansion and energy efficiency measures in public buildings. When it comes to contributing to national energy policy goals, results vary; use of biomass has increased, but selfsufficiency in electricity supply has increased only slightly. The most favourable development when it comes to energy-related emissions is the reduction of carbon dioxide.
Based on shortcomings identified in the studied energy plans and implementation, possibilities to increase the effectiveness and widen the scope of energy planning are discussed. Improvements are discussed in terms of urban planning as well as participative planning, and with respect to the environmental assessment of plans. If energy issues are included in urban planning and a participatory planning approach is used, this could facilitate the implementation of energy plans. Including environmental assessment could facilitate wide scopes and more relevant goals. It is also proposed that the EU framework for environmental assessment of plans and programmes (2001/42/EC) can be used for energy planning, since it includes a comprehensive approach, public participation, and environmental assessment.
27
Stenlund, Jenny. "Plan and reality : municipal energy plans and development of local energy systems /." Linköping : Linköping University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6559.
Full text
28
Cassidy, Ann S., Delphine Le Page, and Sean W. Spender. "Enhancing planning for local energy systems by the strategic sustainable development framework." Thesis, Blekinge Tekniska Högskola, Avdelningen för maskinteknik, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-2908.
Full textAbstract:
The world is facing energy supply challenges. Rising prices and finite reserves of fossil fuels, combined with necessary reductions in their use in order to mitigate anthropogenic climate change, will dramatically reshape the future energy supply. Among the greatest contributors to greenhouse gas emissions are the energy systems that power transportation, heating and cooling, and industrial processes. It is imperative that energy planning is sustainable, secure and effectively implemented for local development. The aim of our research is to enhance the planning process that can aid authorities moving towards sustainable local energy systems. Local energy systems refer to the supply, distribution and use of energy within a municipality. In this study, we advocate applying a strategic sustainable development framework based on 'backcasting from principles of sustainability'. We analyzed global, European Union and Swedish energy objectives, as well as the results of a survey of beacon European cities to inform strategic planning guidelines for authorities moving towards sustainable local energy systems. Our research suggests that the strategic sustainable development framework provides structure to inform strategic and critical decision points for planning and implementing local energy systems.
29
Kaseke, R. "Development of corona-based power supplies for remote repeater stations for overhead HVDC power transmission systems." Thesis, University of Fort Hare, 2012. http://hdl.handle.net/10353/d1006787.
Full textAbstract:
More and more people worldwide are becoming “carbon conscious”. This means they are becoming increasingly aware of the imminent adverse effects of global warming. Of late there has been an urgent drive for governments to be on the forefront of all carbon mitigation initiatives. One such drive involves the United Nations Framework Convention on Climate Change whose parties have been meeting regularly under the banner of Conference of Parties (COP) since 1995. At this conference, parties to the convention review progress made in dealing with climate change. Also key to the deliberations in such meetings are better ways of developing cleaner “carbon free” energy sources. Energy sources of this nature are commonly known as renewable energy sources. In essence global energy trends are constantly moving towards development of more renewable energy sources. It is an undeniable fact that some of viable renewable energy sources especially those with bulk capacity are usually located remotely from load centers. This inevitable reality necessitates the construction of long distance bulk power transmission corridors to link generation sites with load centers. Due to its many inherent advantages over High Voltage Alternate Current (HVAC) for long distance power transmission, High Voltage Direct Current (HVDC) is gradually winning the favor of many utilities. In fact, recent advances in HVDC technology have encouraged many utilities to explore the possibility of harnessing remotely located renewable energy sources which would have otherwise not been viable with HVAC transmission. Through the unfortunate and inevitable phenomenon known as corona effect, overhead HVDC conductors suffer real power losses to the air dielectric surrounding them. Through corona, part of the energy carried on the transmission line is expended through ionization and movement of charges in the air dielectric. This study combined physics, mathematical as well engineering concepts to review corona phenomenon around HVDC lines with specific emphasis on space charge generation and motion within ionized DC fields as well as the influence of temperature on corona discharge or power loss. Also, unlike HVAC, performance of an HVDC system relies heavily on the availability of a reliable and robust telecommunication system. One of the key ways of ensuring reliability of a telecommunication system is by making sure that reliable power supplies are in place to power remote repeater stations. A novel concept of quasi-autonomous corona-based power supply (or QC power supply in short) that works on the principle of magnetohydrodymic (MHD) power generation was developed. A small scale experiment was then designed to assess the feasibility of such power supplies. The experiment was conducted with DC supply of a maximum rated voltage of 30 kVDC and generated up to 6 VDC at an optimum ambient temperature of 23°C. These results have confirmed that with further development QC power supplies have the potential of proving reliable power to remotely located repeaters or any other small critical loads along the stretch of the HVDC transmission line. Practical HVDC transmission systems operate voltages in the excess of 500 kV. By linear extrapolation of the above mentioned results; one would expect to yield up to 100-, 120- and 160-VDC from a 500-, 600- and 800- kV HVDC system, respectively. Although the study succeeded in conceptualizing a CMHD idea upon which the novel QC power supply was developed, quite extensive and rigorous design, modeling, prototyping and experimentation processes are still required before the first QC power supply can be commissioned on a practical HVDC line
30
Verelzen, Wessel. "The effects of 'going local' during the planning process for onshore wind power development." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-448710.
Full textAbstract:
In 2015 a Written Ministerial Statement (WMS) expanded the Localism Act in England which effectively gave neighbourhoods the power to decide on onshore wind power development in their area. By doing so, the planning process for such development ‘went local’. Literature on the effects of ‘going local’ during the planning process for onshore wind power development is conflicting. On the one hand, the involvement of local communities can lead to a higher level of trust and hence a higher success rate of development processes. On the other hand, it appears that people are often reluctant to accept wind power develompent in their own area even though they are in favour of the technology in general. This thesis explores the effects of ‘going local’, in the form of the WMS of 2015 in England, on onshore wind power development by investigating the local and neighbourhood plans, as well as the planning applications, in the administrative County of Cornwall with the help of qualitative document analysis and a thematic analysis framework provided by Braun & Clarke (2006). The results show that currently 4 out of the 213 Parish and Town Councils in the ceremonial county of Cornwall truly comply with the WMS, which means that onshore wind power development will only be possible in these areas. The development in these and all the other neighbourhoods is limited to small-scale clusters of turbines. In addition to this, the results show that there are four over-arching aspects that play a role in the decision-making process of neighbourhoods: i) benefits for the neighbourhood, ii) negative impacts on the neighbourhood area, iii) socio-political attitude, and iv) conditions set by the neighbourhoods or local authorities. The results show that, with the current planning policy framework in England, onshore wind power development will be limited to a significant extent in terms of size and possible locations. The conflicting literature on ‘going local’ reappears in the planning documents and a broad range of factors plays a role for all the neighbourhoods. The given weighting to the different factors is what determines a neighbourhood’s stance on onshore wind power development.
31
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.
Full textAbstract:
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.
32
Sen, Ramen. "A framework for the development of generic virtual reality systems." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327650.
Full text
33
Cornejo, Gómez César Alberto. "Methodology for the development of hydroelectric power plants." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/107592.
Full textAbstract:
Thesis: S.M. in Engineering and Management, Massachusetts Institute of Technology, School of Engineering, System Design and Management Program, Engineering and Management Program, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 73-75).
Hydropower has sufficient resources available and is actively promoted by Governments as part of their energy matrix, but its development is constrained by the difficulty of addressing location particularities, including technical features such as geology or hydrology, and institutional features such as social acceptance, environmental constraints and the regulatory framework. Project results emerge from the interactions of these Inherent Features and the Project Architecture and do not always meet stakeholders' expectations, leading to deficient project results and lost value. This thesis proposes a methodology for prototyping projects to reflect these particularities and inform project shaping and decision-making early in the process. The proposed methodology was built on three systems engineering and project complexity frameworks, and lessons learned from four case studies. Its contribution to hydropower development is related to (i) the incorporation of systems evolution over time on the development process, (ii) the identification and management of relationships among the various decomposed elements of the development, (iii) the identification of emergent properties from the interactions among all features, (iv) a prototype for developers to optimize or search for project architectures that meet stakeholders objectives while complying with restrictions, (v) the delivery of unbiased information for decision-makers, (vi) the opportunity of stakeholders to participate in the project shaping in a continuous fashion, and (vii) the delivery of a tool for the implementation team to evaluate and challenge changes to the project during construction. The usage of this methodology does not guarantee the avoidance of errors or unforeseen project outcomes, but it does reduce the chance for unknown risks emerging from the interactions of the evaluated features.
by César Alberto Cornejo Gómez.
S.M. in Engineering and Management
34
Enriquez, Karla Cecilia. "Development of an ultra-low power sensor for highway health monitoring." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2009. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
Full text
35
Li, Quan, and q. li@cqu edu au. "DEVELOPMENT OF HIGH FREQUENCY POWER CONVERSION TECHNOLOGIES FOR GRID INTERACTIVE PV SYSTEMS." Central Queensland University. School of Advanced Technologies & Processes, 2002. http://library-resources.cqu.edu.au./thesis/adt-QCQU/public/adt-QCQU20020807.152750.
Full textAbstract:
This thesis examines the development of DC-DC converters that are suitable for Module Integrated Converters, (MICs), in grid interactive photovoltaic (PV) systems, and especially concentrates on the study of the half bridge dual converter, which was previously developed from the conventional half bridge converter. Both hard-switched and soft-switched half bridge dual converters are constructed,
which are rated at 88W each and transform a nominal 17.6Vdc input to an output in the range from 340V to 360Vdc. An initial prototype converter operated at 100kHz and is used as a base line device to establish the operational behaviours of the converter. The second hard-switched converter operated at 250kHz and included a coaxial matrix transformer that significantly reduced the power losses related to the transformer leakage inductance. The soft-switched converter operated at 1MHz and is capable of absorbing the parasitic elements into the resonant tank. Extensive theoretical analysis, simulation and experimental results are provided for each converter. All three converters
achieved conversion efficiencies around 90%. The progressive increases in the operation frequency, while maintaining the conversion efficiency, will translate into the reduced converter size and weight. Finally different operation modes for the
soft-switched converter are established and the techniques for predicting the occurrence of those modes are developed. The analysis of the effects of the transformer winding capacitance also shows that soft switching condition applies for both the primary side mosfets and the output rectifier diodes.
36
Yang, Tao. "Development of dynamic phasors for the modelling of aircraft electrical power systems." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/13548/.
Full textAbstract:
As the More-Electric Aircraft (MEA) has been identified as a major trend of future aircraft, the on-board Electrical Power System (EPS) will see significant increased numbers of Power Electronic Converters (PECs) and motor drive systems. In order to study the behaviour and performance of the EPS in MEA, extensive simulation studies need to be done during the system design process. This in return, gives the need to have computationally efficient and accurate models to reduce the design period. In this thesis, the Dynamic Phasor (DP) is used for modelling EPS in the MEA. The DP technique is a general averaging method and naturally a frequency-domain analysis tool. Compared with other averaging models, which is only efficient under balanced conditions, the DP model maintains efficiency under both balanced and unbalanced conditions. The DP technique has been widely used in modelling the constant, single frequency EPS. In this thesis, the DP technique is extended to modelling time-varying frequency EPS. The application of DP in modelling a multi-generator, multi-frequency system is for the first time, developed in this thesis. The developed theory allows a wider application of the DPs. The developed DP model covers key elements in MEA electrical power systems, including the synchronous generator, control, transmission lines, uncontrolled rectifiers, PWM converters and 18-pulse autotransformer rectifier units. The DP model library developed based on this thesis allows the flexibility to study various EPS’s by integrating elements from the library. A twin-generator aircraft EPS, which is based on the More Open Electrical Technology (MOET) large aircraft EPS architecture, is used to demonstrate the application of DP models. Comparing the DP model with the ABC model (models in three-phase coordinates) and the DQ0 model (models in a synchronous dq frame), the efficiency and the accuracy of the DP model are demonstrated under both balanced and unbalanced conditions.
37
Abdullah, Nayeem Mohammad. "Development of distributed generation infrastructure for microgrid connectivity to operational power systems." FIU Digital Commons, 2010. http://digitalcommons.fiu.edu/etd/1099.
Full textAbstract:
Distributed Generation (DG) from alternate sources and smart grid technologies represent good solutions for the increase in energy demands. Employment of these DG assets requires solutions for the new technical challenges that are accompanied by the integration and interconnection into operational power systems.
A DG infrastructure comprised of alternate energy sources in addition to conventional sources, is developed as a test bed. The test bed is operated by synchronizing, wind, photovoltaic, fuel cell, micro generator and energy storage assets, in addition to standard AC generators. Connectivity of these DG assets is tested for viability and for their operational characteristics. The control and communication layers for dynamic operations are developed to improve the connectivity of alternates to the power system. A real time application for the operation of alternate sources in microgrids is developed. Multi agent approach is utilized to improve stability and sequences of actions for black start are implemented. Experiments for control and stability issues related to dynamic operation under load conditions have been conducted and verified.
38
Piper, Andy. "The development of high power, pulsed fiber laser systems and their applications." Thesis, University of Southampton, 2006. https://eprints.soton.ac.uk/42427/.
Full textAbstract:
Due to the recent renewal in interest in fiber laser technology, continuous wave (c.w.) laser technology using rare-earth doped silica fibers has developed rapidly in the past few years. In the late 80s, Erbium Doped Fiber Amplifiers were commercialised and became widely used in the telecommunications industry. Yb-doped silica fiber is particularly attractive as its broad gain bandwidth and high optical efficiency make it a preferred choice for both pulsed and c.w. high power fiber laser and amplifier applications. With the advent of cladding pump technology, low cost, high power broad-stripe semiconductor laser diodes with multimoded radiation could be efficiently used to produce high power Yb-doped silica fiber lasers with either single (~ 1 kW) or multimode (~ 10 kW) emission. Finally, the development and demonstration of a novel gain switched laser diode operating at 1 µm is reported. Using this gain switched laser diode as a seed source; the output gain switched pulses were compressed to 20 ps using a fiber compressor and thereafter amplified to achieve an output average power of 11.1 W at 1 GHz repetition rate using an YDFA cascade. Additional novel work was carried out later where a linearly dispersive CFBG was used to compress the pulses to 16.6 ps. These pulses were later amplified to average powers of 321 W at 1 GHz. This we believe is the highest output power ever achieved for a short pulse fiber laser system.
39
Price, Jonathan Hugh Vaughan. "The development of high power, pulsed fiber laser systems and their applications." Thesis, University of Southampton, 2003. https://eprints.soton.ac.uk/15475/.
Full textAbstract:
Rare-earth doped silica fibers have been used for many years to create continuous-wave lasers, and Er-doped fiber amplifiers are now widely used in telecommunications. In addition, cladding pumped fiber allows the efficient conversion of multimode radiation from high power, low cost, broad-stripe semiconductor laser diodes into the single-mode emission of fiber lasers. With its broad gain bandwidth and high optical conversion efficiency, Yb-doped silica fiber represents an attractive medium for the generation and amplification of high energy ultrashort optical pulses. However, these potential advantages of Yb-doped silica fiber as a gain and nonlinear medium for mode-locked lasers and ultrashort pulse amplifiers have been less well studied, and it was not until 1999 that significant research interest first appeared in Yb-fiber chirp pulse amplifier (CPA) systems. This thesis describes the development of the first practical and stable, femtosecond, Yb-fiber oscillator, and of an Yb-fiber amplifier based CPA system (pulses ~10 μJ, <500 fs). Novel aspects of the system include the use of a high extinction ratio Electro-Optic modulator for pulse selection, and the development of a compact chirped-fiber-Bragg-grating (CFBG) pulse stretcher that provides both 2nd and 3rd order chirp compensation. Recently published theoretical results have demonstrated that the asymptotic solution for ultrashort pulses in a high gain fiber amplifier is a linearly chirped pulse, which can therefore be recompressed with a standard grating compressor. This thesis reports the first experimental comparison of nonlinear pulse evolution towards the asymptotic form using a cascaded amplifier system. The "direct amplification" system was constructed by removing the CPA stretcher grating, which also enabled the use of a less dispersive and more compact compressor. Further system development should lead to the generation of ultrashort pulses at high average power levels and >100 kHz repetition rates. Holey fiber (HF) is a recently developed technology that uses rings of air holes around a solid core to confine the optical field by average-index effects. Fibers are highly suitable for applications using nonlinear optics because of the tightly confined mode and long interaction lengths. The increased mode confinement possible using HF means that small-core, high air-fill fraction HF are an attractive nonlinear medium. Furthermore, the high index contrast in such fibers can create a strong (anomalous) waveguide contribution to the dispersion, and such HFs can have anomalous dispersion at wavelengths <1.3 μm, where conventional fiber has normal dispersion. Therefore HFs can support solitons in new wavelength bands. This thesis reports the first demonstration of linear dispersion compensation, soliton transmission, and visible continuum generation seeded by a 1.06 μm Yb-fiber source. In addition, an experimental study is reported that used HF seeded from a Ti:Sapphire laser to generate continuum in distinct transverse spatial modes of a HF. Numerical simulations suggested that the observed enhancement in UV generation from a higher order mode could be due to differences in the dispersion profiles of the fundamental and higher order transverse modes. Finally, the development of a novel source of <200 fs pulses, continuously tuneable in wavelength from 1.06-1.33 μm, based on the soliton self-frequency-shift principle, is described. The source was constructed from a diode-pumped Yb-doped HF amplifier, and the Yb-fiber oscillator described above. The diode pump power controlled the output wavelength.
40
Khaniya, Dina. "Development of three-phase continuation power flow for voltage stability analysis of distribution systems." Master's thesis, Mississippi State : Mississippi State University, 2008. http://library.msstate.edu/etd/show.asp?etd=etd-11142008-101009.
Full text
41
Wynn, Catherine. "A viable systems analysis of development control services in English Local Planning Authorities." Thesis, Sheffield Hallam University, 2012. http://shura.shu.ac.uk/16562/.
Full textAbstract:
Development Control in England is an important element of the Town and Country Planning process and the economic structure of the country: it is the process which approves or prevents development. Despite this, there is comparatively little research into the processes involved in, and the management of, the decision making process, and there are difficulties effectively researching the process. The Development Control process lies within a changing environment, both with regards to its political and economic influences, but it is vital that it remains effective and efficient throughout changes in its situation. Historically, it has struggled to adapt to these changes, such as the increased demand on its services throughout the 2000’s when it was subject to criticism in particular in relation to housing supply. This study presents a unique examination of Development Control services in England. It examines the barriers which present themselves in the research of its processes, developing a methodology based on the Viable Systems Model of Stafford Beer to overcome these barriers and, most significantly, it successfully applies this methodology, providing a structured examination of the ability of the system to adapt to changes in its environment. This examination is highly original in both its subject matter and its methodology and is, as such, a significant contribution to both the fields of Development Control and the Viable Systems Model. It contributes to the limited research within Development Control, extends the fields to which the Viable Systems Model has been applied and demonstrates the presence of features of the Viable Systems Model in an existing high performing authority. The analysis identified important areas of both good and bad practice and led to recommendations which can assist Development Control services strengthen their ability to recognise and adapt to change. Furthermore, the methodology and recommendations have potential to be applied throughout local authority services, and in other Government provision, to enable services to be effective throughout future changes in their political and economic environments.
42
Sun, Xu, and 孫旭. "Development of power system monitoring by magnetic field sensing with spintronic sensors." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/196015.
Full textAbstract:
This dissertation presents novel application of spintronic sensors in power system monitoring. Spintronic sensors including giant magnetoresistance (GMR) sensors and tunnel magnetoresistance (TMR) sensors are advanced in magnetic field sensing. In power industry, power-frequency magnetic fields are produced by electric power sources, equipment and power lines. Thus it is impossible for monitoring the power system by sensing the emanated magnetic field. In Chapter 2, a novel concept based on magnetoresistive (MR) sensors is proposed for transmission line monitoring. A proof-of-concept laboratory setup was constructed and a series of experiments were carried out for demonstration. The result shows the feasibility of using this power system monitoring method in reality.
In order to handle complicated transmission line configuration with the proposed method, an improved current monitoring technology is proposed in Chapter 3. It is realized by developing a current source reconstruction method based on stochastic optimization strategy. This concept of current monitoring by magnetic field sensing and current source reconstruction was experimentally implemented and verified in our laboratory setup. A typical model of 500 kV three-phase transmission lines was simulated to further corroborate this technology. The reconstruction results for the 500 kV transmission lines verify the feasibility and practicality of this novel current monitoring technology based on magnetic field sensing at the top of a transmission tower for monitoring overhead transmission lines.
Chapter 4 offers further improvement of the transmission-line monitoring technology. Improved technology can measure simultaneously both electrical and spatial parameters of multiple lines in real-time in a non-contact way. Two typical models of high-voltage three-phase transmission lines were simulated and the resulting magnetic fields were calculated. A source reconstruction method was developed to reconstruct the spatial and electrical parameters from the magnetic field emanated by the overhead transmission lines. The reconstruction results for the 500 kV and 220 kV transmission lines verify the feasibility and practicality of this non-contact transmission-line monitoring technology based on magnetic field sensing.
As well as the high-voltage transmission-line, the technology is applied in underground power cable operation-state monitoring and energization-status identification in Chapter 5. The magnetic field distribution of the cable was studied by using finite element method (FEM) for the power cable operating in different states, i.e. current-energized state (the cable is energized and carries load current) and voltage-energized state (the cable is energized but carries no load current). Application of this method was demonstrated on an 11 kV cable with metallic outer sheath. The results highly matched with the actual source parameters of the cable. An experimental setup was constructed and the test results were used for demonstration this method.
In order to enhance the applicability of the proposed power system monitoring technology in practice, magnetic flux concentrators (MFC) and magnetic shielding are studied and designed for MR sensors in Chapter 6.published_or_final_version
Electrical and Electronic Engineering
Doctoral
Doctor of Philosophy
43
Rymut, Joseph E. "Development and Control of a Solar Array Switching Module." Cleveland State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=csu1198769150.
Full text
44
Jooste, Charl Roelof. "Development of a generic digital controller for power electronic applications." Thesis, Cape Peninsula University of Technology, 2011. http://hdl.handle.net/20.500.11838/2210.
Full textAbstract:
Thesis (MTech (Electrical Engineering)))--Cape Peninsula University of Technology, 2011.This thesis presents an investigation into the generic tools, hardware and firmware, involved in power electronic converter control and feedback. The aim was to determine the optimal controller architecture through research of existing controllers. As soon as the architecture was established, design of the controller commenced. Explanations for the various components selected were provided. The design considerations when designing a printed circuit board (PCB) with mixed signals was also presented. The theory behind the control of a multicell converter as well the practical implementation of the control scheme in firmware was presented.
45
Turner, Katherine. "Feeding local economies: Bolivia’s edible biocultural heritage and rural territorial development." Journal of Agroecology and Sustainable Food Systems, 2016. http://hdl.handle.net/1993/31954.
Full textAbstract:
The biocultural heritage and diversity of localised food systems are resources that some communities, governments and other actors are mobilising to pursue their development objectives. However, further understanding is needed to determine how regimes of access and benefit surrounding this collectively held heritage are affected by its use in development projects. This dissertation examines rural development involving interventions in the food systems of the Central Valley of Tarija, Bolivia, and the ripple effects on the people who depend on these systems for their survival as producers, intermediaries and consumers. Core themes relate to personal histories and experiences of change and continuity in household economies and diet, and the role of biocultural heritage within localised food systems. These are examined in relation to processes of territorial construction and ordering through development programs and less planned processes of global and environmental change. Data were gathered through a food systems methodology, acknowledging the complex, interdependent relationships among production, transformation, exchange and consumption. The primary methods used were semi-structured interviews with local producers, intermediaries, consumers and government and non-governmental organisation key informants, complemented by participant observation, surveys, and document review. I found edible biocultural heritage to be a key resource in territorial projects seeking to alter current and future conditions of the Central Valley territory. From the 1970s onward, agricultural production possibilities available to research participant households have narrowed because of land enclosures, market integration, and other intersecting factors ultimately favouring transition towards commodity production (Chapter 2). Some smallholder viticulturalists, however, have incorporated grape production within multi-species agroecosystems to balance the risks and benefits of participation in the expanding commercial sector (Chapter 3). Edible biocultural heritage is being mobilised within multiple territorial projects in the Central Valley, including a gourmet project (Chapter 4) and an alternative food network around campesino gastronomic heritage (Chapter 5), with distinct ecological, economic and sociocultural implications. Whose heritage (or aspects of heritage) is carried forward and given precedence within development processes, and whose is rendered less viable and visible, has significant impacts on food systems’ form and function, the representations of local identity they manifest and the livelihood possibilities they entail.February 2017
46
Nsumbu, Cassandra Daviane. "Development of a soft-core based power electronic conversion controller." Thesis, Cape Peninsula University of Technology, 2014. http://hdl.handle.net/20.500.11838/2379.
Full textAbstract:
Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2014.The application of digital control techniques has become dominant in power electronics owing to several advantages they present, when compared to analogue solutions. Their development is based on the use of microprocessors and microcontrollers, such as Application Specific Integrated Circuit (ASIC), Digital signal processors (DSP), Field Programmable Gate Arrays (FPGA), or a combination of these devices. This thesis presents an investigation of a soft-core based FPGA control system as a solution for power electronic applications. The aim was the development and implementation of a conversion controller, which purpose is to supply control inputs in the form of digital Pulse Width Modulation (PWM) signals, to a number of power electronic applications, such as single half and full bridge DC-DC converters, three phase and multicell inverters. The PWM control technique is achieved via their power semiconductor switching devices. These PWM control signals are necessary for the high frequency conversion of an analog input voltage (AC, DC or unregulated) to an analog output voltage of another level (AC or DC). This was intended to be achieved by exploiting and combining the advantages that FPGA and embedded processors provide such as high reconfigurability and multipurpose ability. This controller’s digital outputs, namely PWM switching signals, can be directly delivered to an analog signal amplification circuit to create an adequate voltage level before being processed by the converters’ switches.
47
Tomsovic, Kevin L. "Development of expert systems as on-line operational aids /." Thesis, Connect to this title online; UW restricted, 1987. http://hdl.handle.net/1773/5995.
Full text
48
Marlette, Jackie. "The Power of Water: The Necessity of Stormwater Drainage Systems in Minnesota." Arizona-Nevada Academy of Science, 2002. http://hdl.handle.net/10150/296591.
Full text
49
Liebman, Adam D. "Opposing hydropower development on China's Nu River a disconnect between urban activists and local residents /." Laramie, Wyo. : University of Wyoming, 2009. http://proquest.umi.com/pqdweb?did=1935311811&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.
Full text
50
Bukhsh, Waqquas Ahmed. "Islanding model for preventing wide-area blackouts and the issue of local solutions of the optimal power flow problem." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/9671.
Full textAbstract:
Optimization plays a central role in the control and operation of electricity power networks. In this thesis we focus on two very important optimization problems in power systems. The first is the optimal power flow problem (OPF). This is an old and well-known nonconvex optimization problem in power system. The existence of local solutions of OPF has been a question of interest for decades. Both local and global solution techniques have been put forward to solve OPF problem but without any documented cases of local solutions. We have produced test cases of power networks with local solutions and have collected these test cases in a publicly available online archive (http://www.maths.ed.ac.uk/optenergy/LocalOpt/), which can be used now by researchers and practitioners to test the robustness of their solution techniques. Also a new nonlinear relaxation of OPF is presented and it is shown that this relaxation in practice gives tight lower bounds of the global solution of OPF. The second problem considered is how to split a network into islands so as to prevent cascading blackouts over wide areas. A mixed integer linear programming (MILP) model for islanding of power system is presented. In recent years, islanding of power networks is attracting attention, because of the increasing occurrence and risk of blackouts. Our proposed approach is quite flexible and incorporates line switching and load shedding. We also give the motivation behind the islanding operation and test our model on variety of test cases. The islanding model uses DC model of power flow equations. We give some of the shortcomings of this model and later improve this model by using piecewise linear approximation of nonlinear terms. The improved model yields good feasible results very quickly and numerical results on large networks show the promising performance of this model.