This report seeks to evaluate and predict possible power quality issues regarding Fortums engagement in the project of Stockholm Royal Seaport. Stockholm Royal Seaport is a city district planned by Stockholm Municipality to be constructed based on sustainable urban city principles. Fortum has, together with additional partners, engaged in the challenge to create a sustainable energy system. This is thought to be achieved through several measures. Energy saving actions are incorporated at several levels and there is a plan to create a “smart grid” for the electricity supply. A smart grid has no strict definition but in this case a key feature is “demand-response” which effectively means a way to optimize the consumption to have a more balanced consumption over the 24 hours of a day. One of the key components in the smart grid is the “active house” which is planned to have several specific features separating it from an ordinary house. It is planned to have its own contribution to electricity production using solar cells and an energy storage using batteries. Another feature is thought to be both automation and economic incentives measures to achieve peak load reduction. This thesis has taken the perspective of the end customer in the active house and has tried to evaluate the power quality to be experienced. An investigation regarding the different components has been carried out to get an overview from the mentioned perspective and identify possible problems or issues that may require attention in the realization of Stockholm Royal Seaport. It has been found that no major problems are to be expected but some smaller issues has arisen that might be worthwhile giving some attention.

<p>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.</p><p>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.</p>

As wind power expands rapidly worldwide, it is becoming more common to build wind farms in alpine locations where the wind resources often are good and conflicting interests are few. This is evident in Sweden where a substantial portion of the large wind parks planned are to be built in cold climate locations. The fact that icing of turbine blades and sensors can severely impact the production raises the question how large the losses are. In this thesis 10 wind parks comprising 45 turbines, well dispersed throughout Sweden are investigated. Daily production figures are compared to wind data from the MERRA reanalysis data-set in order to see if it is possible to determine the level of losses during the winter period caused by cold climate. A method is suggested where a relationship between daily production and daily average wind speed is established using representative summer days. This relationship is then used to calculate an expected production for the winter period. Losses are concluded as the difference between expected and actual production. The method did not produce a consistent and reliable result for the sites investigated. However, the method captures the overall trend with higher losses in the north of Sweden compared to the sites in the south where little or no icing is likely. At the sites where icing is expected, losses in the range of 10 to 20% of the annual production were calculated.

Society relies more and more on a continuous supply of electricity. However, while underinvestments in reliability lead to an unacceptable number of power interruptions, overinvestments result in too high costs for society. To give incentives for a socioeconomically optimal level of reliability, quality regulations have been adopted in many European countries. These quality regulations imply new financial risks for the distribution system operator (DSO) since poor reliability can reduce the allowed revenue for the DSO and compensation may have to be paid to affected customers.This thesis develops a method for evaluating the incentives for reliability investments implied by different quality regulation designs. The method can be used to investigate whether socioeconomically beneficial projects are also beneficial for a profit-maximizing DSO subject to a particular quality regulation design. To investigate which reinvestment projects are preferable for society and a DSO, risk-based methods are developed. With these methods, the probability of power interruptions and the consequences of these can be simulated. The consequences of interruptions for the DSO will to a large extent depend on the quality regulation. The consequences for the customers, and hence also society, will depend on factors such as the interruption duration and time of occurrence. The proposed risk-based methods consider extreme outage events in the risk assessments by incorporating the impact of severe weather, estimating the full probability distribution of the total reliability cost, and formulating a risk-averse strategy. Results from case studies performed show that quality regulation design has a significant impact on reinvestment project profitability for a DSO. In order to adequately capture the financial risk that the DSO is exposed to, detailed risk-based methods, such as the ones developed in this thesis, are needed. Furthermore, when making investment decisions, a risk-averse strategy may clarify the benefits or drawbacks of a project that are hard to discover by looking only at the expected net present value. / QC 20110530

Flywheel systems are attractive in hybrid and electric vehicles due to their ability to handle power during acceleration and braking. The combination of a flywheel device with a battery source has several advantages such as high peak power capacity, high energy density and reduction in the number of charge/discharge cycles of the battery. A flywheel based all-electric driveline is investigated in this thesis. The novelty of the system consists in the use of a double wound flywheel machine, which divides the system in two different power levels. Due to this configuration, the system becomes efficient and can handle the power developed during fast dynamical processes. The complete driveline consists of three main components: the battery, the flywheel machine and the wheel motor. The High-Power (HP) side of the driveline connects the flywheel machine to the wheel motor, whereas the Low-Power (LP) side connects the flywheel machine to the battery. The connections of different components of the system are made electrically through power converter devices. The present thesis focuses on the electrical converters and control strategies used in the flywheel based all-electric driveline. The control of power converters is responsible for the logic and functionality of the driveline, being a challenging step within this project. Different power converter topologies have been investigated: a DC/DC plus a DC/AC converter on the LP side, and an AC/DC/AC converter on the HP side. The design and assembly of the power electronics and their control scheme have been successfully implemented. Different control strategies have been suggested and a complete scaled driveline has been assembled and tested based on previous simulation results. Results have confirmed the functionality of the driveline, where smoothed output power has been obtained from the battery, whereas the flywheel handles power transients on the traction side. An average efficiency of about 87% (battery to wheels) has been obtained. The power converter systems have been shown to be efficient and robust, with control strategies able to handle the peak energy flow in the system. A regenerative braking strategy has been simulated and a wheel-to-wheel efficiency of about 80% has been estimated.

Utsikterna att kunna genomföra en återstart av de två små vattenkraftverk som behandlas i denna rapport år goda. Förutsättningarna är gynnsamma i så måtto att planerna för återstarten ligger väl i linje med praxis som etablerats genom avgöranden i de högre rättsliga instanserna gällande liknande fall. Ägaren planerar att driva verksamheten i stort sett så som den ursprungligen bedrevs, vilket visat sig betydelsefullt för att få återupptag av nedlagd vattenkraftverksamhet godkänt Dessa kraftverk är små, väldigt små. Detta betyder att investeringskostnaderna måste minimeras om det skall finns någon chans att uppnå en acceptabel återbetalningstid för investeringen. Några kostnader kan inte påverkas alls, till exempel anslutningen till elnätet. Vissa, såsom de för nya tuber, intagsgaller, samt kabel och utrustning till kraftverken, kan påverkas i någon mån genom att omsorgsfullt välja leverantörerna av utrustningen, samt välja de mest kostnadseffektiva (ofta liktydigt med de enklaste men ändå fungerande) lösningarna. Några få komponenter, såsom generatorn, kan gå att få tag på som begagnade, vilket hjälper till att hålla nere kostnaderna. Slutligen bör inte de pengar som finns att spara på att göra så mycket som möjligt av arbetet själv underskattas. / The prospects of achieving a restart of the two small hydropower plants studied in this report are good. The basic conditions are favourable in the sense that the plans for a restart are well in line with accepted procedures such as established by decisions in the highest courts regarding similar cases. The owner plans to run the operation in essentially the same way it was originally run, a circumstance which has proven to be important when seeking to get restart of discontinued hydropower activities approved. These power plants are small, very small. This means that investment costs has to be minimized if there is to be any chance of achieving an acceptable pay-off time for the investment. Some can't be affected at all, such as the cost for getting connected to the power network. Some, such as those of new tubes, intake bars and electrical wiring and equipment for the plants, can be affected to some extent by carefully choosing the suppliers of the equipment and choosing the most cost-efficient (in most cases synonymous with the simplest but yet functional) solutions. A few components, such as the generator, can possibly be obtained as used equipment, which helps keeping the costs down. Lastly, the potential of saving money by doing as much as possible of the work yourself should not be underestimated.

<p>In this thesis a method for evaluating investments in small scale hydro power is presented. An analysis of the future position that small scale hydro production will have on the Nordic electricity market is also carried out. This is done by an inventory of technology and economic and environmental aspects. The inventory is also a guide as to how the project should be implemented.</p><p>Hydrolyzer is the name of the Excel tool developed to evaluate investments. The tool requests input data from the user and then evaluates the investment and generates a sensitivity analysis. Several projects or scenarios can be entered and are then ranked after profitability. For example a major repair can be compared to a new power station and tailrace excavations are possible to evaluate.</p><p>The profitability of small scale hydro power investment mainly depends on the size of the initial investment. The power generation costs average among the lowest among possible future power plants. This trend applies to comparisons between renewable and fossil production plants. Electricity prices will probably not fall back to historic levels, due to fuel shortage and increasing environmental concerns. Price prognosis therefore indicates that investments, which on calculation seem profitable, will also be so.</p><p>Small scale hydro investments at existing dams are socio-economically and environmentally sound. The investments contribute with clean power but have local environmental impacts. At existing dams this damage is already done and expensive to undo if at all possible. The</p><p>environmental impacts can be dramatically reduced by construction of fish passages etc. In the thesis an example shows that economic resources for environmental constructions often depend on electricity certificates and that residual flows aren’t greater than necessary.</p><p>An investment project should start by evaluating possible scenarios that the hydro power permit may result in. The transmission capacity should also be investigated at an early stage. Materials should be chosen with care and evaluated with a star diagram. A synchronous</p><p>generator without a speed increaser should be considered for the hydro investment. The turbine type should be suggested by the manufacturer who also has to be able to guarantee efficiencies and cavitation resistance. Submersible turbines should be considered as they significantly reduce building costs. Involved persons need to be experienced and the tenders should be lump sums except for costs which are difficult to determine.</p> / <p>I detta examensarbete presenteras en metod för att enkelt kunna göra en bedömning av om det är lönsamt att investera i småskalig vattenkraft. Det undersöks också hur den småskaliga vattenkraftens förutsättningar på den framtida elmarknaden ser ut. Detta görs genom en inventering av teknik, ekonomi och miljöaspekter. Inventeringen ger också svar på hur ett investeringsprojekt ska genomföras.</p><p>Hydrolyzer kallas excelverktyget som utvecklats för att göra lönsamhetsbedömningen. Det fungerar så att indata matas in och sedan beräknas investeringens lönsamhet och en känslighetsanalys genereras. I verktyget kan olika investeringsalternativ läggas in som sedan beräknas och rangordnas. Exempelvis kan en större reparation jämföras med att bygga en helt ny station eller rensningar utvärderas.</p><p>Småskalig vattenkrafts lönsamhet och produktionskostnader beror till största del på hur stor grundinvesteringen blir. Produktionskostnaden är i snitt bland de billigaste produktionsslagen som kan komma att byggas i framtiden. Trenden gäller vid jämförelse både bland förnybara</p><p>och bland övriga produktionsslag. På elmarknaden pekar det mesta på att priset inte kommer att sjunka tillbaka till historisk nivå. Detta då bränslena är bristvara och att en allt större miljöhänsyn krävs vilket pressar upp priset. Prisutvecklingen talar för att om ett investeringsbeslut tas där kalkylen visar lönsamhet så kommer detta också att infalla.</p><p>Investeringar i småskalig vattenkraft vid befintliga dammar bedöms vara samhällsekonomiskt och miljömässigt fördelaktigt. Småskalig vattenkraft producerar ren el men ger miljöstörningar lokalt. Vid befintliga dammar är dock denna skada redan skedd och väldigt kostsamt att återställa om det överhuvudtaget är möjligt. Miljöproblemen kan dock kraftigt minskas genom byggnation av fiskpassager m.m. Möjligheten att bygga vid befintliga dammar kan vara beroende av elcertifikat om de lokala förutsättningarna är dåliga. I rapporten visas också genom ett exempel att ekonomin för miljöförbättrande åtgärder oftast är beroende av elcertifikat och att mintappningar inte är större än nödvändigt.</p><p>Investeringsprojektet bör börja med att ta fram scenarion att utvärdera utifrån hur vattendomen kan tänkas bli. Elnätets kapacitet ska också undersökas tidigt. Materialen ska väljas med omsorg och utvärderas med stjärndiagram. En synkron generator utan växel ska</p><p>övervägas till kraftverket. Turbintypen ska föreslås av tillverkaren och denna ska kunna garantera verkningsgrader och kavitationsmotstånd. Dränkbara turbiner ska övervägas då dessa kräver väsentligt mindre byggnationsarbeten. Inblandade i projektet ska ha rätt kunskaper och anbuden ska tas in som klumpsummor där visst ansvar tas för svårbestämda kostnader.</p>

<p>The main ambition of this degree project is to illustrate the fundamental problems of today’s electric tariff regulation and the usage of the analyzing tool; The Network Tariff Model. There is a further discussion of potential problems and clear improvements of the 2012 years proposed network tariff regulation. Interviews have been conducted with specific network companies and Energimarknadsinspektionen. The proposed regulation of 2012 is discussed from the government’s proposition.</p><p>This paper clearly shows that the authority´s work has been conducted in a very unprofessional manner during the period of The Network Tariff Model. Transparency has been missing at the same time when quality control has been almost nonexistent from the authority.</p><p>The regulation itself and the usage of The Network Tariff Model generated substantial criticism. Disagreement about the model was mostly about the use of methods and parameter settings.</p><p>The new regulation of beforehand assessment of network tariffs is scheduled to be commissioned during 2012. This regulation has certain advantages compared to today’s for once because it counts for the actual costs for the corporations. At the same time this particular approach will demand a lot of resources of the authority.</p><p>When the regulating models of the future are being developed legitimacy to all parties must be ensured. The regulations must at the same time be adjusted to the resources available for the grid authority. Likewise the process and nature of putting forward new regulations should be based on continuity to greater extent.</p>

Wind power will play a major role in the future energy system in Sweden. Most of the major wind parks are planned to be built in sites where the cold climate and atmospheric icing can cause serious problems. This underlines the importance of addressing these issues. The major cause of these problems is in-cloud icing of the rotor blades due to super cooled liquid droplets of clouds. The droplets freeze upon impact with the rotor blade and form hard rime ice. This rime ice causes disruption in the aerodynamics that leads to production losses, extra loads on the rotor blades and when the ice is shed it poses a safety risk to people in the near environment. This master thesis focuses on how to measure the accretion of ice and the correlation between measured ice and production losses of two wind parks in northern Sweden.   The results show a good correlation between the ice accretion on a stationary sensor and the production loss from a wind turbine. In most icing events the icing of the sensor and large production losses from the wind turbine correlated clearly. Attempts to quantify the production losses at a certain ice rate measured with the stationary sensors was done, however no clear results was produced. The reason for this is that the wind turbines often stop completely during an icing event and that the time series analyzed was too short to be able to quantify the losses at certain wind speed and ice rates.   Recommendations on the type of sensor which should be used was to be produced, however the conclusion was that no single sensor has acted satisfactory and could be recommended to measure ice accretion for wind turbine applications. Due to this, at least two sensors are recommended to increase the redundancy in the measurement system. Modeling ice accretion with standard parameters measured has been done and the results show that the time of icing could be determined quite well when the sensors was ice free, however when the sensors and especially the humidity sensors was iced the time of icing was overestimated.   The main conclusion drawn is that there is a clear relationship between the icing of a stationary sensor and the rotor blade. There is still no which fulfills all demands of measuring ice accretion for wind turbine applications, further it is possible with simple models to roughly determine when icing occurs with standard measurements.

This thesis investigates optimization of the control of electrical and thermal equipment by using FEM and CFD modeling in combination with dynamic simulation models. The thesis focuses on the production of electrical strips and the control system with the aim of reducing losses and improving magnetic properties. Several parameters and factors contribute to core losses. Thickness deviations in strip production, high levels of impurities in the core, orientation, ageing, surface oxidation, overloading, and hot spot temperature are among the reasons for losses in the core. Some of the losses occur during strip cutting and core assembly. This dissertation focuses on the reduction of losses in the cold rolling, annealing and manufacturing stages. The cold rolling process has a direct influence on the accuracy of the strip thickness and magnetic ageing of sheets. Some disturbances such as eccentricity, working rolls gap deviation, shape and edge deflections have to be removed in order to achieve accurate thickness. Thickness measurement makes up an important portion of loss evaluation in electrical equipment. Impurities and dirty strip surfaces in the cold rolling step can increase the carbon content of strips that pass through the annealing furnaces after cold rolling. The slab should be cleaned before reeling and rewinding. As the strip passes through the annealing furnaces, the temperature should be homogenous over the entire strip. According to simulations of furnace and strip temperature computed in the COMSOL environment, homogenous temperatures may be achieved using high electrical power reflectors which are equipped with molybdenum disilicide (MoSi2) electrical heating elements to replace the gas fired burners that are currently used. Modelling of the cold rolling process is conducted in order to find the correlation between control system parameters. A multivariable mathematical model for the rolling process is derived here, which reveals the interactions of the influencing variables. This approach provides numerically efficient algorithms, which are necessary for running in a real-time environment. A control model is applied in the MATLAB environment in order to determine the strip thickness at online-offline state using a robust algorithm. The critical problem in the thickness control loop is analysed, and an adaptive control algorithm is proposed. A number of control methods are investigated to improve the final strip properties. Cold rolled strip thickness deviations, eccentricities and shape defects are compensated for. The simulation results are verified with measurement data and the most significant sources of disturbances are detected. Finally, to solve the hottest spot problem in large scale electric power transformer, a new apparatus, oil spraying, is proposed and analysed. / Denna avhandling behandlar optimering och kontroll av elektrisk och termisk utrustning med hjälp av FEM och CFD-modellering i kombination med dynamiska simuleringsmodeller. Avhandlingen fokuserar på produktion av remsor och styrsystemet i syfte att minska förluster och ge bättre magnetiska egenskaper. Flera parametrar och faktorer bidrar till förluster i kärnan. Tjockleksavvikelser i remsor, höga nivåer av föroreningar i kärnan, orientering, åldrande, yta oxidation, överbelastning och temperaturer i heta punkter finns bland orsakerna till förlusterna i kärnan. Några av de förluster som uppstår under klippning av remsor och ihopsättningen av kärnan. Denna avhandling fokuserar på att minska förlusterna i produktionsstegen för kallvalsning och  glödgning. Kallvalsningen har ett direkt inflytande på riktigheten av remsornas tjocklek och magnetiska åldrande. Vissa störningar i till exempel excentriciteten, gapet mellan valsarna, form och kanter måste minimeras för att uppnå korrekt tjocklek. Tjockleksmätningar utgör en viktig del av utvärderingen av förluster  i elektrisk utrustning. Föroreningar och smutsiga bandytor i kallvalsningssteget kan öka kolhalten i band som passerar genom ugnar efter kallvalsning. Valsämnet bör rengöras innan avhaspling och upprullning. När bandet passerar genom glödgningsugnar bör temperaturen vara homogen över hela remsan. Enligt simuleringar av ugnen och remsans temperatur kan homogen temperatur uppnås med elektriska värmeelement (Molybden disilikat, MoSi2) insatta i reflektorer. De kan ersätta den gaseldade brännare som för närvarande används. Modellering av kallvalsningsprocessen sker i syfte att hitta korrelation mellan styrsystemparametrar. En multivariabel matematisk modell för valsningsprocessen har tagits fram som använder korrelation mellan variabler. Denna metod ger numeriskt effektiva algoritmer som behövs för att köra i en realtids-miljö. En modell har tagits fram för att bestämma remsornas med tjocklek för kontinuerlig och icke-kontinuerligt tillstånd med hjälp av en robust algoritm. Det kritiska problemet i reglerloopen för tjocklek har analyserats, och en adaptiv regleralgoritm föreslås. Ett antal metoder har undersökts för att förbättra de slutliga bandegenskaperna. Avvikelser i kallvalsade band med avseende på tjocklek, excentriciteter och form kompenseras. Simuleringsresultaten har verifierats med mätdata och de viktigaste källorna till störningar upptäckts.   Slutligen, för att lösa problemet med heta punkter i stora transformatorer föreslås en ny metod för oljesprutning, vilken också analyseras i avhandlingen.