Distributed Series Reactors (DSRs) can be used to control power flow to more fully utilize the capacity of a transmission network, delaying investment in new transmission lines. In this study the IEEE 39 bus standard test system is modified to a 3-phase, unbalanced model consisting of 230 kV, 345 kV and 500 kV lines, where lines of different voltage run in parallel. This model is used to study load growth and the effect of adding DSRs to alleviate resulting overloads, and in particular to alleviate overloads on lines of different voltage running in parallel. The economic benefit of adding DSRs to the network is compared to the addition of new transmission lines in the network. In the second part of the work, the effect of unsymmetrical operation of DSRs on a single transmission line is studied and compared to the symmetrical operation of DSRs. It is found that the unsymmetrical operation of DSRs is more economical. Finally the unsymmetrical operation of DSRs to reduce voltage imbalance in the network is considered. / Master of Science

The efficiency of an assembly line depends on how the different tasks are distributed among the work stations that make up the assembly line. Assigning the tasks to the stations is called assembly line balancing (ALB) and is an NP-hard optimization problem. While automating line balancing has the potential to make manufacturing more efficient, and the problem has been studied for many decades, the research has not been widely adopted by industry, where planning is still largely done manually. This thesis discusses reasons for this theory-practice gap and suggests a direction that is more focused on real-world applications. This includes shifting the focus to a decision support system (DSS) rather than considering the ALB solver in isolation. Such a shift places the solver in a new context, where it plays a slightly different role and needs to fulfill slightly different requirements. A framework for building practical ALB solvers within a DSS context is proposed and then evaluated by implementing solvers for two different assembly line models. Increasingly refined versions of the ALB solvers are compared to each other, showing that the most specialized version performs substantially better than the simplest, which demonstrates that this framework allows an effective trade-off between development time and performance. One of the implemented solvers is also pitted against a state-of-the-art solver for the Simple Assembly Line Balancing Problem type 1 (SALBP-1) by comparing its results on a standard set of problem instances against the best published results. The comparison shows that the implemented solver is not just competitive but in some ways superior. On the largest instances, it produces improved solutions for 99 % of the instances that had not already been solved optimally, reducing the number of stations by more than 2 % on average. The solvers also demonstrated the potential to effectively trade off running time and solution quality, which is an important feature in an interactive system that is meant to support an iterative refinement process.

The energy market is evolving, with a prediction of heavily increased consumption and, consequently, increased production. In parallel, EU directives with targets prioritising fossil-free electricity production, reduction of greenhouse gas emissions and becoming climate neutral by 2050, poses a challenge for the current state of electricity production in the Nordics. In managing these predictions, the electricity production from renewable energy sources is required to be increased threefold by 2045. Consequently, the share of intermittent energy sources is deemed to heavily increase, resulting in need of more capacity of energy storage, ancillary services and balancing of the grid. Energy storage systems, such as pumped storage hydropower, can play a crucial role in this energy market transition. However, pumped storage hydropower has yet to be fully explored or proven viable for large-scale investments in the Nordics. In this thesis, the viability and profitability of pumped storage hydropower plants in the Nordics are investigated. The viability assessment was conducted through a SWOT analysis based on a summary of literature and interviews within a PESTLE framework. The interviewees consisted of experts active in different fields of work at Fortum, with knowledge relevant for the purpose of this thesis. To assess the profitability, an investment analysis tool for pumped storage hydropower plants was created in MathWork’s MATLAB, focusing on one of Fortum’s already existing pumped storage hydropower plants. The investment analysis tool was built for several cases with fixed operating schedules using a weekly timeframe.  Through the SWOT analysis, potential challenges for pumped storage hydropower were found in investment costs, topology dependence, development of nuclear power production and increased difficulty in obtaining greenfield permits. Regarding opportunities, Fortum’s pumped storage hydropower plants were found to be favourably and strategically located in SE3, beneficial in generating income from different revenue streams as well as highly beneficial in assisting the development of Sweden’s future energy market. The results obtained from the investment analysis tool indicated that market volatility plays a crucial role in determining the profitability of pumped storage hydropower projects. In a highly volatile market, there is a great possibility to yield large amounts of profit. However, to fully maximise profit, especially in a low volatility market, constant optimisation of pumped storage hydropower operations through advanced forecasting and modelling is crucial.

Hybrid organizations, such as the Royal Dramatic Theater (Dramaten) in Sweden, face the challenge of balancing conflicting institutional logics and their prescribed goals. Dramaten, as the national stage for theater, is expected to uphold high artistic standards set by its sole owner, the Swedish state. At the same time, it has efficiency goals to meet as a joint-stock company. This study aimed to understand if the quantifiability of goals, derived from different logics, impacts the prioritization of goals within hybrid organizations. Through a qualitative case study of Dramaten, the findings suggest that the most influential actor, rather than the quantifiability of goals, determines the prioritization of goals within the organization. In other words, who is giving directions seems to influence the balancing act more than the nature of the different goals. Additionally, the study found that efforts to make all goals equally measurable may not necessarily affect the prioritization of goals but can help reduce internal confusion.

Following the publication of the European Union Global Strategy in 2016 where the EU officially announced its quest for European Strategic Autonomy (ESA), a policy initiative toenable EU’s capacity to act autonomously in the realm of security and defence, this study poses the following research question: What type of foreign policy behaviour does the EU exhibit in security and defence through its quest for strategic autonomy? Broadly based in realism, the study is designed as a single case-study of EU foreign policy behaviour in relation to Russia and analyses whether the pursuit of ESA entails a balancing or hedging EU foreign policy behaviour. By doing so, the study contributes theoretically, by disentangling and operationalising these two concepts analytically, and empirically, by applying them to an EU context and investigating their presence. The results show that the EU does not exhibit a hedging behaviour towards Russia, and whether the EU exhibits a balancing behaviour remains inconclusive as the empirical material provided insufficient evidence to conclude so.

Compression of vector-valued datasets is increasingly needed for addressing the significant storage and transmission burdens associated with research activities in large-scale computational fluid dynamics and environmental science. However, vector-valued compression schemes have traditionally received few investigations within the data-compression community. Consequently, this dissertation conducts a systematic study of effective algorithms for the coding of vectorvalued datasets and builds practical embedded compression systems for both static and timevarying vector fields. In generalizing techniques from the relatively mature field of image and video coding to vector data, three critical issues must be addressed: the design of a vector wavelet transform (VWT) that is amenable to vector-valued compression applications, the implementation of vector-valued intraframe coding that enables embedded coding, and the investigation of interframe-compression techniques that are appropriate for the complex temporal evolutions of vector features. In this dissertation, we initially invoke multiwavelets to construct VWTs. However, a balancing problem arises when existing multiwavelets are applied directly to vector data. We analyze extensively this performance failure and develop the omnidirectional balancing (OB) design criterion to rectify it. Employing the OB principle, we derive with a family of biorthogonal multiwavelets possessing desired balancing and symmetry properties and yielding performance far superior to that of VWTs implemented via other multiwavelets. In the second part of the dissertation, quantization schemes for vector-valued data are studied, and a complete embedded coding system for static vector fields is designed by combining a VWT with suitable vector-valued successive-approximation quantization. Finally, we extend several interframecompression techniques from video-coding applications to vector sequences for the compression of time-varying vector fields. Since the complexity of temporal evolutions of vector features limits the efficiency of the simple motion models which have been successful for natural video sources, we develop a novel approach to motion compensation which involves applying temporal decorrelation to only low-resolution information. This reduced-resolution motion-compensation technique results in significant improvement in terms of rate-distortion performance.

No description available.

No description available.

No description available.

No description available.