Nach dem erheblichen Anstieg der Stromnetzentgelte in Deutschland in den vergangenen zehn Jahren ist zu erwarten, dass dieser Trend im Zuge der Energiewende weiterhin anhält: Der Zubau großer Kapazitäten von Windenergie- und Photovoltaikanlagen erfordert ebenso umfassende Investitionen in den Ausbau der Stromnetze, um die eingespeiste Energie abtransportieren zu können. Aufgrund der ungleichen Verteilung geeigneter Flächen, insb. für den Ausbau der Windenergie, sind und werden die Verbraucher in EE-starken Regionen von diesen Netzkosten ungleich höher belastet als Kunden in Regionen mit niedrigeren EE-Kapazitäten. Um diese Asymmetrie der Kostenbelastung abzumildern, beabsichtigt die Bundesnetzagentur, einen bundesweiten Wälzungsmechanismus zur Verteilung der EE-bedingten Netzkosten in Form einer bundesweit einheitlichen Umlage einzuführen. In der hier vorliegenden Analyse sind erstmals die langfristigen Auswirkungen dieser Reform mit Blick auf den voranschreitenden EE-Ausbau abgeschätzt. Im Ergebnis zeigt sich, dass im Jahr 2040 über die Hälfte der in Verteilungsnetzen anfallenden Kosten über die Umlage bundesweit gewälzt werden könnten. Von dieser Umverteilung profitieren überwiegend Kunden in ländlichen Gebieten, während Verbraucher insbesondere in großen Städten und kleineren Netzgebieten künftig erheblich höhere Lasten tragen müssen. Das Ziel einer gleichmäßigeren Beteiligung aller Verbraucher an den EE-bedingten Netzkosten wird damit zwar erreicht, zugleich bleiben jedoch künftige Herausforderungen unadressiert.:Zusammenfassung A 1 Aktueller Stand und historische Entwicklung der Stromnetzentgelte 1 2 Was zeigt der Vergleich der Abschätzung der Netzentgeltentwicklung mit den Ist-Netzentgelten? 4 3 Welche Ansätze für eine Netzentgeltsystematik bestehen? 9 3.1 Bestehende und künftige Herausforderungen 9 3.2 Optionen für eine effiziente kurzfristige Netzbewirtschaftung 10 3.3 Optionen zur Verteilung der Kapitalkosten für die Aufrechterhaltung und Weiterentwicklung der Netzinfrastruktur 12 4 Welche Änderungen der Entgeltsystematik werden vorgeschlagen? 15 4.1 Funktionsweise der gegenwärtigen Netzentgeltsystematik 15 4.2 Vorschlag der Bundesnetzagentur für einen bundesweiten Wälzungsmechanismus 17 4.3 Wesentliche Kritik der Stellungnahmen zum Eckpunktepapier 19 4.4 Anpassungen am Wälzungsmechanismus im Festlegungsentwurf der Bundesnetzagentur 22 4.5 Alternative Ansätze zur Netzkostenverteilung 23 5 Welche Auswirkungen sind von einer überregionalen Wälzung zu erwarten? 25 5.1 Auswirkungen des Wälzungsmechanismus im Status Quo 25 5.2 Auswirkungen des Wälzungsmechanismus bei Erreichen der EEG-Ausbauziele 27 5.2.1 Erfüllung der Ausbauziele für Windenergie 27 5.2.2 Erfüllung der EEG-Ziele für Photovoltaik 29 5.2.3 Erfüllung der EEG-Ziele für Wind und PV 30 6 Schlussfolgerungen der Analyse 32 Anhang 34 Literaturverzeichnis 35

Master of Science / Department of Electrical Engineering / William B. Kuhn / During the development of an educational renewable energy production platform, it was found that there were no low-cost, efficient grid-tie interfaces for a 160 W DC wind turbine. Typically, a small DC wind turbine is used in conjunction with a rechargeable battery bank or, if the wind turbine is directly interfaced with a grid-tie inverter, a regulator with a diversion-load. The use of batteries is undesirable due to their high-cost and high-maintenance characteristics. Diversion loads by nature waste power, as any excess energy that cannot be accepted by a battery or inverter is usually converted into heat through a resistive element. Initially, a 24 V DC, 160 W Air Breeze small wind turbine was directly connected to an Enphase Energy M190 grid-tie micro-inverter. The 24 V DC Air Breeze wind turbine is designed to charge a battery or bank of batteries while the M190 micro-inverter is designed to convert the DC output of a 200 W solar panel to grid-tied AC power. As expected, the power-production response time associated with the small wind turbine and the power-accepting, load-matching response time of the micro-inverter were not compatible. The rapidly changing power output of the small wind turbine conflicted with the slow response time of the micro-inverter resulting in little power production. Ultimately, the response time mismatch also produced sufficiently large voltage spikes to damage the turbine electronics. In this thesis, a solution for a low-cost, efficient grid-tie interface using no batteries and no diversion load is presented. A capacitance of eight Farads is placed in parallel with the small wind turbine and the micro inverter. The large capacitance sufficiently smoothes the potential abrupt voltage changes produced by the wind turbine, allowing the micro-inverter adequate time to adjust its load for optimal power conversion. Laboratory experiments and data from an implementation of such a parallel super capacitor wind turbine to grid-tie micro-inverter configuration are provided along with DC and AC power production monitoring circuits interfaced with a micro controller.

Master of Science / Department of Electrical and Computer Engineering / Caterina M. Scoglio / The need for reliable and quick communication in the power grid is growing and becoming more critical. With the Smart Grid initiative, an increasing number of intelligent devices, such as smart meters and new sensors, are being added to the grid. The traffic demand on the communications network increases as these new devices are being added. This can cause issues such as longer delay, dropped packets, and equipment failure. The power grid relies on this data to function properly. The power grid will lose reliability and will not be able to provide customers with power unless it has correct and timely data. The current communications network architecture needs to be evaluated and improved. In this thesis, a simulator program is developed to study the communications network. The simulation model is written in C++ and models the components of the communications network. The simulation results provide insight on how to design the communications network in order for the system to be robust from failures. We are using the simulator to study different topologies of the communications network. The communications network often has a simular topology to the power grid. This is because of right-a-ways and ownership of equipment. Modifying the topology of the communications network slightly can improve the performance of the network. Security of the communications network is a very important aspect. There is a risk of successful attacks on the communications network without the implementation of security protocols. Attacks can come from malicious users of the communications network or from entities outside the network. These attacks may lead to damaged equipment, loss of power to consumers, network overload, loss of data, and loss of privacy. This thesis presents a short overview of the major issues related to the security of the communications network. The department of Electrical and Computer Engineering (ECE) at Kansas State University (K-State) is working on developing a Smart Grid lab. Burns and McDonnell has collaborated with the ECE department at K-State to develop the Smart Grid Lab. This lab will be located inside of the ECE department. The lab will consist of both power grid equipment and network communication equipment. This thesis describes similar labs. It then describes the initial plan for the lab, which is currently in the planning stage.

Nowadays, electricity markets are becoming more deregulated, especially development of smart grid and introduction of renewable energy promote regulations of energy markets. On the other hand, the uncertainties of new energy sources and market participants’ bidding bring more challenges to power system operation and transmission system planning. These problems motivate us to study spot price (also called locational marginal pricing) of electricity markets, the strategic bidding of wind power producer as an independent power producer into power market, transmission expansion planning considering wind power investment, and analysis of the maximum loadability of a power grid. The work on probabilistic spot pricing for a utility grid includes renewable wind power generation in a deregulated environment, taking into account both the uncertainty of load forecasting and the randomness of wind speed. Based on the forecasted normal-distributed load and Weibull-distributed wind speed, probabilistic optimal power flow is formulated by including spinning reserve cost associated with wind power plants and emission cost in addition to conventional thermal power plant cost model. Simulations show that the integration of wind power can effectively decrease spot price, also increase the risk of overvoltage. Based on the concept of loacational marginal pricing which is determined by a marketclearing algorithm, further research is conducted on optimal offering strategies for wind power producers participating in a day-ahead market employing a stochastic market-clearing algoivrithm. The proposed procedure to drive strategic offers relies on a stochastic bilevel model: the upper level problem represents the profit maximization of the strategic wind power producer, while the lower level one represents the marketing clearing and the corresponding price formulation aiming to co-optimize both energy and reserve. Thirdly, to improve wind power integration, we propose a bilevel problem incorporating two-stage stochastic programming for transmission expansion planning to accommodate large-scale wind power investments in electricity markets. The model integrates cooptimizations of energy and reserve to deal with uncertainties of wind power production. In the upper level problem, the objective of independent system operator (ISO) modelling transmission investments under uncertain environments is to minimize the transmission and wind power investment cost, and the expected load shedding cost. The lower level problem is composed of a two stage stochastic programming problem for energy schedule and reserve dispatch simultaneously. Case studies are carried out for illustrating the effectiveness of the proposed model. The above market-clearing or power system operation is based on direct current optimal power flow (DC-OPF) model which is a linear problem without reactive power constraints. Power system maximum loadability is a crucial index to determine voltage stability. The fourth work in this thesis proposes a Lagrange semi-definite programming (SDP) method to solve the non-linear and non-convex optimization alternating current (AC) problem of the maximum loadability of security constrained power system. Simulation results from the IEEE three-bus system and IEEE 24-bus Reliability Test System (RTS) show that the proposed method is able to obtain the global optimal solution for the maximum loadability problem. Lastly, we summarize the conclusions from studies on the above mentioned optimization problems of electric power market under modern grid, as well as the influence of wind power integration on power system reliability, and transmission expansion planning, as well as the operations of electricity markets. Meanwhile, we also present some open questions on the related research, such as non-convex constraints in the lower-level problem of a bilevel problem, and integrating N-1 security criterion of transmission planning. / Graduate / lei.ming296@gmail.com

This thesis considers how an assessment method for reinvestments in the distribution grid can be designed and implemented. The assessment method was created to give long-term estimations of the amount overhead lines that could be substituted with underground cables and how to prioritize between different areas. The regulation of power grid companies was reviewed to highlight important factors for profitable reinvestments. The assessment method was implemented for overhead lines in Ellevio´s distribution grid using the database program FME and validated against real reinvestment decisions in a case study area called Sinntorp. The resulting reinvestment proposals mainly consist of replacing older grid sections and sections where expensive maintenance is planned in the future. The script show similar results as real reinvestment decisions but small differences are noticed related to the script’s hard focus on older grid sections. The script has potential to be used on Ellevio´s entire overhead line network but this requires work to complete essential data. Further validation on new areas are also desired to see if results are reasonable and if the script can be developed to consider more reinvestment factors.

No description available.

Master of Science / Department of Electrical and Computer Engineering / Caterina M. Scoglio / In recent times, research in the field of complex networks has advanced by leaps and bounds. Researchers have developed mathematical models for different networks such as epidemic networks, computer networks, power grid networks, and so on. In this thesis, the power grid has been modeled as a complex network. The power grid is being used extensively in every field today. Our dependence on the power grid has exceeded to an extent that we cannot think of survival without electricity. Recently, there has been an increasing concern about the growing possibility of cascading failures, due to the fact that the power grid is works close to full utilization. Furthermore, the problem will be exacerbated by the need to transfer a large amount of power generated by renewable sources from the regions where it is produced to the regions where it is consumed. Many researchers have studied these networks to find a solution to the problem of network robustness. Topological analysis may be considered as one of the components of analysis of a system's robustness. In the first part of this thesis, to study the cascading effect on power grid networks from a topological standpoint, we developed a simulator and used the IEEE standard networks for our analysis. The cascading effect was simulated on three standard networks, the IEEE 300 bus system, the IEEE 118 bus test system, and the WSCC 179 bus equivalent model. To extend our analysis to a larger set of networks with different topologies, we developed a first approximation network generator the creates networks with characteristics similar to the standard networks but with different topologies. The generated networks were then compared with the standard networks to show the effect of topology on the robustness of power grid networks. A comparison of the network metrics for the standard and the generated networks indicate that the generated networks are more robust than the standard ones. However, even if the generated topologies show an increased robustness with respect to the standard topologies, the real implementation and design of power grids based on those topologies requires further study, and will be considered as future work. In the second part of this thesis, we studied two mitigation strategies based on load reduction, Homogeneous load reduction and Targeted range-based load reduction. While the generic Homogeneous strategy will only mitigate the severity of the cascade when a non-negligible load reduction is performed, our newly proposed targeted load reduction strategy is much more efficient, reducing the load only in a small portion of the grid. The determination of this special portion of the grid is based on an algorithm, which finds the paths supplying power from the generators to the nodes. This algorithm is described in details in the Appendix B. While the Homogeneous strategy is easier to implement, efficient results can be obtained using the targeted strategy.

Dans de proches années, les véhicules électriques (VEs) vont faire leur apparition massive sur les marchés. Cela peut avoir un impact important sur le fonctionnement des réseaux d’électricité actuels qui devront ajuster leur fonctionnement à la nouvelle demande massive d'électricité provenant des VEs. Par contre, les VEs peuvent aussi être vus comme une nouvelle opportunité dans le futur marché d’électricité. En effet, une décharge/recharge intelligente peut permettre aux VEs d’être un support de stockage d’électricité important, valable, et permanent dont la capacité croit en fonction du nombre des VEs. Ce projet a comme objectifs de : (1) proposer un schéma d’interaction V2G (Vehicle-to-Grid) intégrant des techniques permettant de : (a) adapter le fonctionnement de la grille aux contraintes temporelles et spatiales relatives au processus de recharge des VEs dans un milieu résidentiel. On cherchera à satisfaire de différentes demandes en puissance des VEs branchés au secteur sans trop stresser la grille intelligente, (b) optimiser les opérations de chargement/déchargement entre les VEs et la grille dans les deux sens. (2) Proposer de nouveaux schémas de communication sans fil, entre les VEs et la grille intelligente loin des bornes de recharge, qui soient basés sur les standards de communications véhiculaires (VANETs) ainsi que sur d’autres standards de communication à grande échelle. On introduira des techniques d’accès à la grille intelligente pour négocier le coût de recharge/décharge des batteries, le temps d’attente du service, les emplacements et aussi pour planifier la motivation du consommateur afin de favoriser la stabilité de la grille.

This thesis investigates the potential to reduce greenhouse gas emissions relating to electrical power provision at UK music festivals. It has been carried out in partnership with a number of UK festival organisers and power providers. The thesis provides a literature review of sustainable event management and the associated electrical power provision, before then investigating the existing methodologies for quantifying greenhouse gas emissions at festivals. This review identified a lack of data regarding energy demand at events other than total fuel demand. While energy data does not improve the accuracy of GHG accounting, it provides more detail which can identify opportunities to reduce these emissions. Data was gathered from 73 power systems at 18 music festivals from 2009-2012. This produced typical festival power load profiles for different system types including stages, traders and site infrastructure. These load profiles were characterised using a series of indicators that can create performance benchmarks, in addition to increasing the detail of carbon auditing. Analysis of the load profiles identifies opportunities for emission reduction. These address either the supply or demand for power in order to reduce on site fuel consumption. These opportunities include changes in operating procedure to reduce demand during non-operational periods, utilising low energy equipment on stages, and using a power provision system capable of adjusting power plant supply to meet demand. The work has documented power demand at festivals, and highlighted opportunities for change that can reduce costs and emissions, as well as informing festivals on their practices.

Asperger syndrome is a relatively recent diagnostic classification. Several factors, including a high prevalence of mental illness, mean receiving a diagnosis in adulthood is a very unique experience but remarkably there is little literature about the impact on individuals. Instead the dominance of the medical/psychiatric paradigm pervades and limits understanding and possibilities. The main implication is a lack of clarity about what support services are needed and effective, and as such the needs of this population are often overlooked. This is the first study to explore the sense of self among a sample of males and females diagnosed with Asperger syndrome in adulthood using social constructionist and constructivist ideas. It was interested in whether personal construal of the self before diagnosis and self after diagnosis were differentiated. Given the importance in the development of self-concept of discriminations between the self and others, the research also sought to explore how people diagnosed with Asperger syndrome in adulthood construe other people with and without Asperger syndrome. Using the repertory grid and other techniques from Personal Construct Psychology (Kelly, 1955) in combination with a semi-structured interview, this study presents a novel exploration of idiosyncrasies and commonalities across a demographically diverse sample of eight participants. An extended analysis of a unique subsample of women diagnosed aged 50 years and over was undertaken. Both cognitively complex and simple construct systems were found across the sample. Findings indicated the self before diagnosis was construed critically and was more elaborated than the self after diagnosis. Several participants had a reduced sense of self following diagnosis. The diagnosis offered an explanation of symptoms but for some participants these symptoms were a way of life and accommodating the new label with the existing view of self posed challenges. An overarching and striking theme was the sense of difference felt by participants before and after diagnosis. This study offers a fresh insight into a virtually unexplored population which, through dissemination, may influence the way clinical psychologists and other practitioners work to support adults diagnosed with Asperger syndrome. Recommendations for clinical practice included approaches that target the need for individuality, commonality and sociality, and should be gender-specific where possible. Such approaches might elaborate multiple aspects of self, the diagnosis and related dilemmas. They should support people to widen their perceptual field to alternative ways of construing and explore change. The mixed method approach was assessed to be a strength of the study and a number of recommendations for future research are presented.