Factors that could enable the development of a distribution system for hydrogen applied to heavy-duty vehicles in Sweden are studied in this thesis. Fuel cell and hydrogen technology could be a solution in an electrification mix to reduce the environmental impacts of heavy-duty vehicles (Neef, 2009). However, the distribution system for hydrogen in Sweden is limited, with only five hydrogen refueling stations geographically dispersed (Vätgas Sverige, n.d.). In addition, distribution options at the lowest-cost delivery mode are highly dependent on the hydrogen application, density of demand, quantity to be transported, and distance between the delivery point and the production (Bersani, et al., 2018) To determine what factors could be decisive to develop a distribution system, the technological innovation system framework has been applied in this study. The analysis is carried out with the framework’s system functions. Further, the analysis is based on literature on hydrogen that considers hindering factors and barriers, policy recommendations, lock-in effects, distribution and transportation, and centralized vs. de-centralized systems. Moreover, data has been collected through 11 semi-structured interviews with actors from different sectors, energy companies, truck manufacturers, and researchers, amongst others. The analysis concludes that cross-sectoral collaboration, pilot testing, and governmental support can be enabling factors for the development of a distribution system in Sweden. / Faktorer som kan möjliggöra utvecklingen av ett distributionssystem för vätgas applicerat för tunga fordon i Sverige studeras i den här studien. Tekniken för bränsleceller och vätgas kan vara en lösning i en elektrifieringsmix för att minska miljöpåverkan från tunga fordon (Neef,2009). Distributionssystemet för vätgas i Sverige är dock begränsat, med endast fem vätgastankstationer som är geografiskt spridda (Vätgas Sverige, n.d.). Dessutom är distributionsalternativen till lägst kostnad i hög grad beroende av väteapplikationen, efterfrågan, kvantitet som ska transporteras och avståndet mellan leveranspunkten och produktionen (Bersani, et al., 2018). För att avgöra vilka faktorer som kan vara avgörande för att utveckla ett distributionssystem har ramverket för teknisk innovation system tillämpats i den här studien. Analysen utförs med ramverkets systemfunktioner. Vidare baseras analysen på litteratur om väte som tar hänsyn till hindrande faktorer och barriärer, policyrekommendationer, lock-in-effekter, distribution och transport och centraliserade kontra decentraliserade system. Dessutom har data samlats ingenom 11 halvstrukturerade intervjuer med aktörer från olika sektorer, energibolag, lastbilstillverkare och forskare, bland annat. Utifrån analysen dras slutsatsen att sektorsövergripande samarbete, pilottestning och statligt stöd är faktorer som kan möjliggöra en utveckling av ett distributionssystem för vätgas i Sverige.

The effects of corrosion inhibitors on water quality and the distribution system were studied. This dissertation investigates the effect of inhibitors on iron surface roughness, copper surface roughness, and copper release. Corrosion inhibitors included blended poly/ortho phosphate, sodium orthophosphate, zinc orthophosphate, and sodium silicate. These inhibitors were added to a blend of surface water, groundwater, and desalinated brackish water. Surface roughness of galvanized iron, unlined cast iron, lined cast iron, and polyvinyl chloride was measured using pipe coupons exposed for three months. Roughness of each pipe coupon was measured with an optical surface profiler before and after exposure to inhibitors. For most materials, inhibitor did not have a significant effect on surface roughness; instead, the most significant factor determining the final surface roughness was the initial surface roughness. Coupons with low initial surface roughness tended to have an increase in surface roughness during exposure, and vice versa, implying that surface roughness tended to regress towards an average or equilibrium value. For unlined cast iron, increased alkalinity and increased temperature tended to correspond with increases in surface roughness. Unlined cast iron coupons receiving phosphate inhibitors were more likely to have a significant change in surface roughness, suggesting that phosphate inhibitors affect stability of iron pipe scales. Similar roughness data collected with new copper coupons showed that elevated orthophosphate, alkalinity, and temperature were all factors associated with increased copper surface roughness. The greatest increases in surface roughness were observed with copper coupons receiving phosphate inhibitors. Smaller increases were observed with copper coupons receiving silicate inhibitor or no inhibitor. With phosphate inhibitors, elevated temperature and alkalinity were associated with larger increases in surface roughness and blue-green copper (II) scales.. Otherwise a compact, dull red copper (I) scale was observed. These data suggest that phosphate inhibitor addition corresponds with changes in surface morphology, and surface composition, including the oxidation state of copper solids. The effects of corrosion inhibitors on copper surface chemistry and cuprosolvency were investigated. Most copper scales had X-ray photoelectron spectroscopy binding energies consistent with a mixture of Cu2O, CuO, Cu(OH)2, and other copper (II) salts. Orthophosphate and silica were detected on copper surfaces exposed to each inhibitor. All phosphate and silicate inhibitors reduced copper release relative to the no inhibitor treatments, keeping total copper below the 1.3 mg/L MCLG for all water quality blends. All three kinds of phosphate inhibitors, when added at 1 mg/L as P, corresponded with a 60% reduction in copper release relative to the no inhibitor control. On average, this percent reduction was consistent across varying water quality conditions in all four phases. Similarly when silicate inhibitor was added at 6 mg/L as SiO2, this corresponded with a 25-40% reduction in copper release relative to the no inhibitor control. Hence, on average, for the given inhibitors and doses, phosphate inhibitors provided more predictable control of copper release across changing water quality conditions. A plot of cupric ion concentration versus orthophosphate concentration showed a decrease in copper release consistent with mechanistic control by either cupric phosphate solubility or a diffusion limiting phosphate film. Thermodynamic models were developed to identify feasible controlling solids. For the no inhibitor treatment, Cu(OH)2 provided the closest prediction of copper release. With phosphate inhibitors both Cu(OH)2 and Cu(PO4)·2H2O models provided plausible predictions. Similarly, with silicate inhibitor, the Cu(OH)2 and CuSiO3·H2O models provided plausible predictions.

Information and communication technologies are being implemented more than ever in the power industry in order to make smarter power grids, termed as cyber-physical power systems (CPPSs). Along with the privileges of such modern power networks like reducing the total operation cost for end-use customers, they may be negatively affected by cyberattacks, above all false data injection (FDI) attacks as they are easier to be performed. As a case in point, an adversary can detour security systems, penetrate into the cyber layer of a typical CPPS, and manipulate the information, finally leading to security threats. Although prevention and detection mechanisms are significant tools to be utilized by power system operators to improve the reliability of such systems against cyberattacks, they cannot ensure the security of power grids since some FDI attacks might be designed to bypass the detection stage. Hence, a more powerful tool will be required, which is called remedial action scheme (RAS), to be implemented by power system operators to recover the targeted power grid in a timely manner. Toward this end, different RAS frameworks are presented in this dissertation in transmission, distribution, and microgrid levels to highlight the effectiveness of such reaction mechanisms in case of cyber threats targeting modern power systems. In the transmission level, optimal power flow (OPF) integrated with thyristor controlled series capacitor (TCSC) have been utilized to design a RAS to mitigate the negative impacts of FDI attacks, resulting in system congestion or power outages. In the distribution level, system operators take advantage of static VAR compensator (SVC) through solving a customized version of distribution feeder reconfiguration (DFR) problem to mitigate voltage violations in the form of overvoltages and undervolatges, caused by FDI cyberattacks. In light of the fact that some FDI attacks bypass the employed detection methods, it is crucial to prepare in advance for such scenarios. Hence, in this dissertation, a real-world framework is also proposed for mitigating false data injection (FDI) attacks targeting a lab-scale wind/PV microgrid and resulting in power shortage. The proposed RAS is developed as a hardware-in-the-loop (HIL) testbed within the cyber-physical structure of the smart microgrid. Finally, as a prerequisite of the proposed intelligent RAS, which is able to be used on different levels of a CPPS, power system operator is being in attacker’s shoe to scrutinize different scenarios of cyberattacks to make an initial archive set. The design of such mechanisms incorporates long-short-term memory (LSTM) cells into a deep recurrent neural network (DRNN) for the processing of archived data, termed intelligent archive framework (IAF), identifying the proper reaction mechanisms for different FDI cyberattacks. To react to cyberattacks for which similar pre-investigated remedial measures were not saved in the IAF, a power flow analysis is considered to a) examine the interdependency between transmission and distribution sectors and b) generate appropriate RASs in real time.

Detta examensarbete beskriver hur en Monte Carlo simulering (MCS) kan användas för tillförlitlighetsanalys av ett eldistributionssystem. Metoden har implementerats i verktyget RADPOW som nu kan utföra både analytiska och numeriska beräkningar. Angreppssättet för att utveckla denna MCS metod i RADPOW innefattade följande aktiviteter: • Vidareutvecklade av RADPOW med införandet av ett grafiskt användargränssnitt för Windows. • Utveckling och implementering av en iterativ analytisk metod för känslighetsanalys av eldistributionssystem i RADPOW. • Utveckling och implementering av MCS metoden i RADPOW, vilken placerades i en fristående modul kallad Sim. Den implementerade MCS metoden har validerats i en jämförande studie innefattande två testsystem med datorprogrammet NEPLAN. Resultat från denna studie visar att MCS metoden ger samma resultat som den analytiska metoden i RADPOW och det kommersiella verktyget NEPLAN. / This master thesis describes an implementation of a Monte Carlo Simulation (MCS) method for reliability assessment of electrical distribution systems. The method has been implemented in the reliability assessment tool RADPOW which now is able to perform both analytical and simulation evaluations. The main contributions within this thesis includes the following activities; • Further development of RADPOW by the introducing of a graphical user interface for Windows. • Development and implementation of an analytical sensitivity analysis routine for RADPOW. • Development and implementation of a sequential MCS method in RADPOW in a stand alone module referred to as Sim. The implemented MCS method has been validated in a comparable study for two case systems by a commercial software NEPLAN. Results shows that the implemented MCS method provides the same results as the analytical method in RADPOW and the NEPLAN software.

In reregulated and restructured electricity markets the production and retail of electricity is conducted on competitive markets, the transmission and distribution on the other hand can be considered as natural monopolies. The financial regulation of Distribution System Operators (DSOs) has in many countries, partly as a consequence of the restructuring in ownership, gone through a major switch in regulatory policy. From applying regulatory regimes were the DSOs were allowed to charge their customers according to their actual cost plus some profit, i.e. cost-based regulation, to regulatory models in which the DSOs performance are valued in order to set the allowable revenue, i.e. Performance-Based Regulation (PBR). In regulatory regimes that value performance, the direct link between cost and income is weakened or sometimes removed. This give the regulated DSOs strong cost cutting incentives and there is consequently a risk of system reliability deterioration due to postponed maintenance and investments in order to save costs. To balance this risk the PBR-framework is normally complemented with some kind of quality regulation (QR). How both the PBR and QR frameworks are constructed determines the incentive that the DSO will act on and will therefore influence the system reliability development. This thesis links the areas of distribution system reliability and performancebased regulation. First, the key incentive features within PBR, that includes the quality of supply, are identified using qualitative measures that involve analyses of applied regulatory regimes, and general regulatory policies. This results in a qualitative comparison of applied PBR models. Further, the qualitative results are quantified and analysed further using time sequential Monte Carlo simulations (MCS). The MCS enables detailed analysis of regulatory features, parameter settings and financial risk assessments. In addition, the applied PBRframeworks can be quantitatively compared. Finally, some focus have been put on the Swedish regulation and the tool developed for DSO regulation, the Network Performance Assessment Model (NPAM), what obstacles there might be and what consequences it might bring when in affect. / QC 20101221

A DC power distribution system (PDS) of a transport aircraft was modeled and analyzed using MATLAB/Simulink software. The multi-level modeling concept was used as a modeling approach, which assumes modeling subsystem of the PDS at three different levels of complexity. The subsystem models were implemented in Simulink and combined into the whole PDS model according to certain interconnection rules. Effective modeling of different scenarios of operation was achieved by mixing subsystem models of different levels in one PDS model. Linearized models were obtained from the nonlinear PDS model for stability analysis and control design. The PDS model was used to examine the system stability and the DC bus power quality under bidirectional power flow conditions. Small-signal analysis techniques were employed to study stability issues resulting from subsystem interactions. The DC bus stability diagram was proposed for predicting stability of the PDS with different types of loads without performing an actual stability test based on regular stability analysis tools. Certain PDS configurations and operational scenarios leading to instability were identified. An analysis of energy transfer in the PDS showed that a large energy storage capacitor in the input filter of a flight control actuator is effective for reduction of the DC bus voltage disturbances produced by regenerative action of the actuator. However, energy storage capacitors do not provide energy savings in the PDS and do not increase its overall efficiency. / Master of Science

[pt] Fontes renováveis são importantes recursos a serem agregados aos sistemas de energia elétrica em prol da descentralização da geração. Discussões acerca dos efeitos ambientais direcionam os estudos em busca de alternativas que possibilitem minimizar a emissão de gases poluentes e diversifiquem a matriz elétrica. Nesse contexto, a geração distribuída (GD) de natureza renovável vem se mostrando cada vez mais presente, alterando a estrutura clássica do sistema e conferindo um maior protagonismo do consumidor. Assim, torna-se essencial avaliar o desempenho dessas novas redes de distribuição no atendimento à demanda, de modo a estabelecer padrões adequados e monitorá-los através das agências reguladoras. Há uma diversidade de métodos de avaliação do desempenho dessas redes, principalmente através dos conceitos de confiabilidade, para lidar com as falhas de equipamentos e os efeitos decorrentes. A presente tese tem como objetivo avaliar índices de confiabilidade de sistemas de distribuição na presença de GD. Para isso, são apresentadas três técnicas baseadas em simulação Monte Carlo (SMC). Uma clássica, denominada SMC sequencial, tem como objetivo modelar a natureza cronológica do problema bem como as incertezas provenientes da intermitência de fontes de GD. A segunda, baseada na SMC quase sequencial, caracteriza-se por sua simplicidade e capacidade em manter a flexibilidade da SMC sequencial, porém, com melhor desempenho em termos de precisão e tempo de processamento. Por último, uma SMC baseada nos conceitos de transição de estado do sistema de forma cronológica assegura também precisão e flexibilidade à técnica. Novas funções teste são propostas para alcançar tal objetivo. Dois sistemas com inserção de GD são utilizados para avaliar o desempenho dos conceitos e técnicas propostas: IEEE RBTS, rede acadêmica padrão amplamente utilizada na área de confiabilidade; e uma rede real. A discussão exaustiva dos resultados confirma que as propostas cumprem os objetivos estabelecidos. / [en] Renewable sources are important resources to be added to electrical energy systems in favor of decentralized generation. Discussions about environmental effects drive the studies in search of alternatives that make it possible to minimize the emission of polluting gases and diversify the electrical matrix. In this context, distributed generation (DG) of a renewable nature has been increasingly present, changing the classic structure of the system and giving greater engagement to the consumer. Therefore, it is essential to evaluate the performance of these new distribution grids in meeting the power demand, in order to establish appropriate standards and monitor them through the regulatory agencies. There is a diversity of methods for evaluating the performance of these networks, mainly through reliability concepts, to deal with equipment failures and the resulting effects. This thesis aims to evaluate reliability indices of distribution systems in the presence of DG. To this end, three techniques based on Monte Carlo simulation (MCS) are presented. A classic one, called sequential MCS, aims at modeling the chronological nature of the problem as well as the uncertainties arising from the intermittency of the DG sources. The second one, based on a quasi-sequential MCS, is characterized by its simplicity and ability to maintain the flexibility of sequential MCS, but with better performance in terms of precision and processing time. Finally, an MCS based on the concepts of chronological system state transition, also provides precision and flexibility to the reliability assessment. New test functions are proposed to achieve this goal. Two systems with DG insertion are used to evaluate the performance of the proposed concepts and techniques: IEEE RBTS, a standard academic network widely used in the reliability area; and another real network. The exhaustive discussion of the results confirms that both proposals meet the established objectives.

This study is about the transition to NDC standard protocol in the business ecosystem of flightticket distribution. The key actors included are airlines, travel agencies and content aggregators(system suppliers). The thesis analyses the current state of the transition to NDC done by thekey actors of the business ecosystem of flight ticket distribution with digital transformationmaturity perspectives, including dimensions, which are relevant for the transition. A conceptual framework has been created and includes six digital transformation maturityperspectives with attached dimensions that can impact the transition to NDC for the businessecosystem with the actors included in the scope of this thesis. The conceptual framework hasbeen created based on previous research on the topic of NDC and used as a foundation to createthe interview protocol and to structure and categorize the empirical results and analysis. The result of this thesis is a compilation of the answers to the interview protocol with tworespondents from two different airlines, three respondents from two different travel agenciesand two respondents from one content aggregator (system supplier). The result answers thequestion of how every organization is working with the different perspectives, and itsdimensions, of digital transformation maturity perspectives in their transition to NDC. Fromthe answers of the respondents, it has also been possible to identify central themes of the keyactors' work that was not originally part of the conceptual framework. The transition to NDC is an ongoing process and the different key actors are working with thedifferent perspectives, including the dimensions, in their transition to NDC. Based on theanswers from the respondent of this study, updates have been made to the conceptualframework to cover all the central themes of the key actors work with digital transformationmaturity perspectives and dimensions in their transition to NDC. The key actors are dependenton each other working with every perspective, and dimension, of the digital transformationmaturity perspectives and if the work with one perspective falls behind for one actor there areripple effects for the other key actors. Key words: NDC Standard Protocol, Flight ticket distribution, Business Ecosystem, Digitalmaturity, Airlines, Travel agency, GDS, Global distribution system

The Thesis deals with the current problem related to the connection of dispersive sources to the distribution network. The advantageous legislative support, however, gives a rapid rise to the sources of this kind. Current pricing philosophy favours in particular the growth of photovoltaic power plants. The introduction is aimed at the dispersive sources locating so as to give a comprehensive solution and better understanding of this issue. The equipments of this kind are located in accordance with legislation in force; however, it is necessary to formulate the possibilities of placing them from the view of rational use of the area with the aim of the public weal accordance of both public and private interests. Talking about connection of the new dispersive sources to the distribution network, it is important to mention the legislation, legal directives and regulations delimitating this kind of trade. This theme is the subject of another chapter of the work. Particular attention is paid to the regulation on conditions of connection to the distribution network. When connecting the sources to the distribution network the biggest technical problem from the view of electrical engineering is undesirable influence on the quality parameters (voltage) in this network. This is in particular the voltage change after connection, then, depending on the type of source, the emission of the current harmonic, sharp voltage change, etc. Considering current rise of the dispersive sources connected to the distribution network, more and more influence will appear in quantity parameters. For this reason there will be a lot of search for the methods of preventing from the negative influence on the network. From all of the above said reasons, the work is aimed at the operation analysis of the part of the distribution network, calculation of the network qualitative parameters and searching for the methods of negative influence rectification owing to switching processes of the distribution system. So as to determine the quantitative parameters we used the E-influence programme. Final paragraphs are devoted to the changes to come not only in legislation but, in general, in the approach of the distribution system operators not only to the ways of another connection of such sources but even the regulation of the dispersive sources already connected.

Unsafe and unnecessary injections are administered in many developing and transitional countries. Injection device security is recommended in order to improve injection safety. Injection device stock depletions have been reported to contribute to unsafe injection practices. Poor distribution of health products has been reported in many parts of Uganda including Mpigi district. As a way of improving injection safety, this study explored the challenges encountered in maintaining an effective distribution system. A Cross-sectional, descriptive study of public and private-not-for-profit health care units in Mpigi district was conducted. 38 health care facilities were selected by stratified disproportionate sampling. Data on device security, the use of equipment and the distribution system were collected and analysed using descriptive statistics. / Health Studies / M.A. (Public Health)