Syfte: Motviktad enbenscykling är en ny träningsmetod som kan användas för att öka intensiteten. Tidigare studier har påvisat att det finns skillander mellan dominant och icke-dominant ben vid cykling med två ben. Syftet med denna studie var att undersöka fysiologiska assymetrier vid motviktad enbenscykling. Metod: Åtta undersökningsdeltagare (ålder 24,1 ± 4,2 år, längd 177,0 ± 5,5 cm, vikt 74,6 ± 9,0 kg, vo2max 69,0 ± 6,4 ml/kg/min) deltog i studien. Undersökningsdeltagarna delades in slumpmässigt i två grupper (dominant eller icke-dominant). För att bestämma undersökningsdeltagarens dominanta ben användes Waterloo Footedness Questionnaire. Den dominanta gruppen utförde första intervallen vid testtillfälle två med sitt dominanta ben och den icke-dominanta gruppen med sitt icke-dominanta ben.Vid testtillfälle ett utfördes ett standardiserat nivåtest till utmattning på cykel. Testtillfälle två, som utfördes minst 48 timmar senare, bestod av fyra stycken tio minuters intervaller av motviktad enbenscykling, varannat ben. Testtillfälle två kördes blint. Resultat: Skillnader kunde observeras men dock inga signifikanta skillnader. Tendensen var att man uppmätte en högre effekt med dominant ben (dominant ben 168 ±18,9 W, icke-dominant ben 162 ±18,1W), men en högre kadens med icke-dominant ben (dominant ben 93 ± 12,7 rpm, icke-dominant ben 95 ± 10,3 rpm). Slutsats: Skillnader finns mellan dominant och icke-dominant ben vid motviktad enbenscykling, dock inga signifikanta skillnader. Vår slutsats är att inlärningseffekten påverkade resultatet i denna studie. För att motverka detta i framtida studier angående motviktad enbenscykling bör undersökningsdeltagarna genomgå en invänjningsperiod med träningsmetoden. / Purpose: Counterweighted single-leg cycling is a new training method that can be used to increase intensity. Studies have shown differences between dominant and non-dominant leg during normal cycling. The purpose of this study was to analyse physiological assymetries during counterweighted single-leg cycling. Method: Eight volunteers (age 24,1 ± 4,2 years, height 177,0 ± 5,5 cm , weight 74,6 ± 9,0 kg, vo2max 69,0 ± 6,4 ml/kg/min) participated in this study. Participants were randomly divided into two groups (dominant or non-dominant). Waterloo Footedness Questionnaire was used to decide participants dominant leg. The dominant group used their dominant leg in the first interval at the second test, and the non-dominant group used their non-dominant leg in the first interval. At the first test a standarized incremental cycling test was performed until exhaustion. The second test , >48 hours later, consisted of four ten-minute intervals of counterweighted single-leg cycling, alternating legs.The second test was blinded. Results: Differences were observed, but no significant differences. Tendencies showed a higher power-output with the dominant leg (dominant leg 168 ±18,9 W, non-dominant leg 162 ±18,1W), but a higher cadence with the non-dominant leg (dominant leg 93 ± 12,7 rpm, non-dominant leg 95 ± 10,3 rpm). Conclusion: Differences exist between dominant and non-dominant leg in counterweighted single-legged cycling, but no significant differences. Our conclusion is that the learning effect affected the results in this study. To counteract this in future studies concerning counterweighted single-legged cycling the studies should include a learning period with the training method.

Le travail présenté dans cette thèse porte sur l'étude du dimensionnement d'une chaine de conversion électrique en entrainement direct d'un système direct de récupération de l'énergie des vagues (searev). Cette chaine de conversion est composée d'une génératrice synchrone à aimants permanents solidaire d'un volant pendulaire, d'un convertisseur électronique composé de deux ponts triphasés à modulation de largeur d'impulsion, l'un contrôlant la génératrice, l'autre permettant d'injecter l'énergie électrique au réseau. En complément, un système de stockage de l'énergie (batterie de supercondensateurs) est destiné au lissage de la puissance produite. Le dimensionnement de tous ces éléments constitutifs nécessite une approche d'optimisation sur cycle, dans un contexte de fort couplage multi-physique notamment entre les parties hydrodynamique et électromécanique. Dans un premier temps, l'ensemble génératrice-convertisseur, dont le rôle est d'amortir le mouvement d'un volant pendulaire interne, est optimisé en vue de minimiser le coût de production de l'énergie (coût du kWh sur la durée d'usage). Cette optimisation sur cycle est réalisée en couplage fort avec le système houlogénérateur grâce à la prise en compte conjointe de variables d'optimisation relatives à l'ensemble convertisseur-machine mais aussi à la loi d'amortissement du volant pendulaire. L'intégration d'une stratégie de défluxage, intéressante pour assurer un fonctionnement en écrêtage de la puissance, permet, dès l'étape de dimensionnement, de traiter l'interaction convertisseur-machine. Dans un second temps, la capacité énergétique du système de stockage de l'énergie fait l'objet d'une optimisation en vue de la minimisation de son coût économique sur cycle de vie. Pour ce faire, nous définissons des critères de qualité de l'énergie injectée au réseau, dont un lié au flicker, et nous comparons des stratégies de gestion de l'état de charge tout en tenant compte du vieillissement en cyclage des supercondensateurs dû à la tension et à leur température. Dans un troisième temps, à partir de données d'états de mer sur une année entière, nous proposons des dimensionnements de chaines de conversion électrique qui présentent les meilleurs compromis en termes d'énergie totale récupérée et de coût d'investissement. / The work presented in this thesis sets forth the study of the sizing of a direct-drive electrical conversion chain for a direct wave energy converter (SEAREV). This electrical chain is made up of a permanent magnet synchronous generator attached to a pendular wheel and a power-electronic converter made up of two three-phase pulse width modulation bridge, one controlling the generator, the other allowing injecting electrical energy into the grid. In addition, an energy storage system (bank of supercapacitors) is intended to smooth the power output. The sizing of all these components needs an operating cycle optimization approach, in a system context with strong multi-physics coupling, more particularly between hydrodynamical and electromechanical parts. At first, the generator-converter set, whose role is to damp the pendular movement of an internal wheel, is optimized with a view to minimize the cost of energy (kWh production cost). This optimization, based on torque-speed operating profiles, is carried out considering a strong coupling with the wave energy converter thanks to the consideration as design variables, some relatives to the generator-converter sizing but also some relatives to the damping law of the pendular wheel. In addition, the consideration of a flux-weakening strategy, interesting to ensure a constant power operation (levelling), allows, as soon as the sizing step, to deal with the generator-converter interaction. In a second step, the rated energy capacity of the energy storage system is being optimized with a view of the minimization of its economical life-cycle cost. To do this, we define quality criteria of the power output, including one related to the flicker, and we compare three energy managment rules while taking into account the power cycling aging of the supercapacitors due to the voltage and their temperature. In a third step, from yearly sea-states data, we provide sizings of the direct-drive electrical conversion chain that are the best trades-offs in terms of total electrical produced energy and economical investment cost.

The main point of this thesis is the extension of the complex solar radiation simulator, the creation of new functionalities, and the cooperation of this complex simulator with the PV power plant. This work builds on the work done in the area of solar radiation modeling. The thesis deals with the continuation, or improvement of some shortcomings, removing shortcomings, such as fixing the beginnings and ends of the simulation, correcting the calculation of sunrise and sunset, but also adding different types of clouds, combinations of different preset cloud situations, or data input, and more. These deficiencies are found in the bachelor's thesis "Complex Simulator of the solar irradiance", and PSCAD is the main tool in this work. Another important point of this work is the realization of the simulation where an improved solar radiation simulator works in cooperation with a model of a photovoltaic panel or a PV power plant, respectively. It has different operating states created in PSCAD. These include, for example, cloud crossings, both over the entire power plant and only partial. In addition, there are experiments that prove the fact that the direction of the incoming cloud plays a role in the power of the PV power plant.

This thesis focused on creating a model of a small hydropower plant model (SHPP) and a part of the electricity network in the simulation software "PSCAD" (basing on real sources). The model will be specified on the basis of the data obtained from the measurements to correspond with the real equipment.

Several measurements may be used as error signals to determine how to appropriately control a sound field. These include pressure, particle velocity, energy density and intensity. In this thesis, numerical models are used to show which signals perform best in is free-field active noise control (ANC) using error sensors located in the near field of the sound sources. The second is equalization in a free field and a semi-free field. Minimized energy density total power output (MEDToPO) plots are developed; these indicate the maximum achievable attenuation for a chosen error sensor as a function of location. A global listening area equalization coefficient (GLAEC) is found to evaluate the performance of the equalization methods. It is calculated by finding the average of the spectral standard deviation of several frequency response measurements in a specified listening area. For free-field ANC employing error sensors located in the near field, pressure-based measurements perform the best. For free-field equalization over an extended listening region, total energy density performs best. Equalization of an extended listening region is more successful over a limited low-frequency bandwidth.

The main objective of wave energy converters (WECs) is to ensure reliable electricity production at a competitive cost. Two challenges to achieving this are ensuring an efficient energy conversion and offshore survivability.         This thesis work is structured in three different sections: Control and maximum power optimization, forces and dynamics analysis in extreme wave conditions, and statistical modeling of extreme loads in reliability analysis.        The need for prediction and future knowledge of waves and wave forces is essential due to the non-causality of the optimal velocity relation for wave energy converters. Using generic concepts and modes of motion, the sensitivity of the prediction horizon to various parameters encountered in a real system is elaborated. The results show that through a realistic assumption of the dissipative losses, only a few seconds to about half a wave cycle is sufficient to predict the required future knowledge for the aim of maximizing the power absorption.          The results of a 1:30 scaled wave tank experiment are used to assess the line force and dynamic behaviour of a WEC during extreme wave events. Within the comparison of different wave type representations, i.e. irregular, regular and focused waves, of the same sea state, the results show that not all the wave types deliver the same maximum line forces. As a strategy of mitigating the line forces during extreme wave events, changing the power take-off (PTO) damping may be employed. With consideration of the whole PTO range, the results indicate an optimum damping value for each sea state in which the smallest maximum line force is obtained. Although wave breaking slamming and end-stop spring compression lead to high peak line forces, it is possible that they level out due to the overtopping effect. Waves with a long wavelength result in large surge motion and consequently higher and more damaging forces.         On the investigation of reliability assessment of the wave energy converter systems, computing the return period of the extreme forces is crucial. Using force measurement force data gathered at the west coast of Sweden, the extreme forces are statistically modelled with the peak-over-threshold method. Then, the return level of the extreme forces over 20 years for the calm season of the year is computed.

The dissertation analyses a possibility to install a steam turbine for steam reduction in the heating plant with a combined cycle, Červený Mlýn. In the first part of this work the constituent parts of Červený Mlýn plant are briefly described. Basic information is included about two considered solutions to the steam turbine for steam reduction. Then the thermic diagram of the whole heating plant and the heat exchanger station itself is presented. On the basis of the given values of the heat required in the hydrothermal system, duration of the steam flow through both variants of the steam turbine for steam reduction is determined. The thermodynamic calculation of the steam turbine for steam reduction is aimed at determination of the power output and its comparison with the power outputs of the steam turbines for steam reduction considered. In the economical profitability calculation, basic economical quantities are given for both the solutions and the more suitable solution is recommended.

The deployment of large-scale photovoltaic (PV) systems is rising in the Swedish power system, both in quantity and in system size. However, the intermittent characteristics of the PV production raises questions concerning the stability in the electric power grid, and power output fluctuations from the PV systems can lead to voltage quality issues. Hence, the distribution system operator E.ON Energidistribution and the solar energy developer company Solkompaniet are interested in investigating potential challenges and possibilities related to the integration of large-scale PV systems in the electric power grid. This thesis studies fast voltage variations in the electric power grid due to output fluctuations from large-scale PV systems, and examines the possibility to mitigate the voltage variations by reactive power support strategies in the PV inverters. Four studies are carried out to investigate the prerequisites for establishing large-scale PV systems. Firstly, a worst-case study considering eight existing substations in the electric power grid as well as a new substation is carried out, to examine the impact of different parameters on the voltage variations. Parameters such as transformer operation mode, location of the point of connection, switching mode and load capacity are compared in the study. Further, time series calculations are done to investigate the voltage variations over one year, and a study with an oversized PV system is done to investigate the possibility for increasing the PV capacity without grid reinforcements. Lastly, a study is performed with reactive power compensation from the PV inverters to examine the possibility to maintain a stabilized voltage level at the point of connection. The studies are performed in E.ONs network model in the power system simulator software PSS/E, with data for the transmission grid, the regional grid, and parts of the distribution grid included. PV systems with a rated capacity from 32 MWp and upwards are connected to substations in the regional grid, where fast voltage variations on nominal voltage levels of 20/10 kV are studied and evaluated from the perspective of the power producer. From this thesis, it can be concluded that neither of the implemented studies results in voltage variations that violate E.ONs technical requirements on fast voltage variations in the point of connection. Further, the results from the worst-case study show the importance of analysing the specific system of interest when connecting PV systems, since the properties of the existing system have an impact on the voltage variations. The time series calculations show that the voltage variations over a time period of one year are highly influenced by the PV production and the load capacity in the substation, and the study with an oversized PV system shows the possibility for increasing the PV capacity without curtailing large amounts of active power. Finally, the study with reactive power compensation concludes that grid support strategies in the PV inverters may be a key solution for making optimal use of the existing electric power grid and enabling the continued expansion of large-scale PV systems in the Swedish power system. / Utbyggnaden av storskaliga solcellsanläggningar (PV) ökar i det svenska kraftsystemet, både i kvantitet och i systemstorlek. De intermittenta egenskaperna hos energiproduktionen väcker emellertid frågor angående stabiliteten i elnätet, och effektförändringar från anläggningarna kan leda till spänningskvalitetsproblem. Därför är distributionssystemoperatören E.ON Energidistribution och solenergiföretaget Solkompaniet intresserade av att undersöka potentiella utmaningar och möjligheter relaterade till integrationen av storskaliga solcellsanläggningar i elnätet. Detta examensarbete studerar snabba spänningsvariationer i elnätet till följd av effektförändringar från storskaliga solcellsanläggningar, och undersöker möjligheten att mildra spänningsvariationerna genom strategier för reaktiv effektreglering i växelriktare.  Fyra studier genomförs för att undersöka förutsättningarna för att etablera storskaliga solcellsanläggningar. För det första genomförs en värsta-fallstudie med beaktande av åtta befintliga stationer i elnätet samt en ny station, för att undersöka olika parametrars påverkan på spänningsvariationerna. Parametrar som transformatorns driftläge, plats för anslutningspunkten, omkopplingsläge och lastkapacitet jämförs i studien. Vidare görs tidsserieberäkningar för att undersöka spänningsvariationerna över ett år, och en studie med en överdimensionerad solcellsanläggning görs för att undersöka möjligheten att öka solcellskapaciteten utan elnäts- förstärkningar. Slutligen genomförs en studie med reaktiv effektkompensation från växelriktare för att undersöka möjligheten att upprätthålla en stabiliserad spänningsnivå i anslutningspunkten. Studierna utförs i E.ONs nätverksmodell i programvaran PSS/E för kraftsystemsimuleringar, med data för transmissionsnätet, regionnätet och delar av distributionsnätet inkluderat. Solcellsanläggningar med en nominell kapacitet från 32 MWp och uppåt ansluts till stationer i regionnätet, där snabba spänningsvariationer på nominella spänningsnivåer om 20/10 kV studeras och utvärderas ur kraftproducentens perspektiv. Från resultaten kan man dra slutsatsen att ingen av de genomförda studierna resulterar i spänningsvariationer som överskrider E.ONs tekniska krav på snabba spänningsvariationer i anslutningspunkten. Vidare visar resultaten från värsta-fallstudien vikten av att analysera det specifika systemet vid anslutning av solcellsanläggningar, eftersom egenskaperna hos det befintliga systemet har en inverkan på spänningsvarationerna. Tidsserieberäkningarna visar att spänningsvariationerna över en tidsperiod av ett år påverkas starkt av både energiproduktionen och lastkapaciteten i stationen, och studien med en överdimensionerad solcellsanläggning visar på möjligheten att öka den nominella kapaciteten utan att spilla stora mängder aktiv effekt. Slutligen ger studien med reaktiv effektkompensation slutsatser om att strategier i växelriktare kan vara en möjlig lösning för att utnyttja det befintliga elnät optimalt och möjliggöra en fortsatt expansion av storskaliga solcellsanläggningar i det svenska kraftsystemet.

Aim The main aim of this study was to investigate the longitudinal effects on cycling performance using a polarized and periodized scheme that was highly supervised and controlled. The second aim was to investigate the effect of using Hyperoxia. The questions used to address the aim were: (1) How does overall performance change after a six-week training intervention? (2) What is the time-course and pattern of performance changes to the training scheme? (3) How does the performance change within the groups?   Method Nineteen male and female cyclists started the study (13 male and 6 female), however only 12 completed it (8 male and 4 female). The characteristics for the 12 subjects were:  age (year) 33.6 ± 6.8, height (cm) 177 ± 9.1, body mass (kg) 73.4 ± 8.8. Using a randomized, double blind design, the test subjects were divided in to hyperoxia (HOT) (n = 6) and normoxia (NOT) (n = 6) training groups.  Over a six week period the subjects followed a controlled polarized periodization that included 15 high intensity interval training (HIIT) sessions (3 x 8 min, 3 x 8 + 4 min, 4 x 8 min & 4 x 4 min) on maximal sustainable intensity (isoeffort) on a cycle ergometer. The dosage of oxygen was administered intermittently by the oxelerate device. A 20 min all out test was performed as pre- and post test.    Results The whole group (n = 12) increased mean power output (W) by 6.4 % (P = 0.002). The relative power output (W/kg) increased significantly 8.2 % (P = 0.0011). The HOT group (n = 6) increased their power output by 8.3 % (P = 0.028) and their relative power output increased by 9.4 % (P=0.011). The whole group (P = 12) significantly increased their VO2mean by 4.1 % (P = 0.03) and in the relative value by 5.4 % (P = 0.01) on the 20 min all out test. The whole group also had a significant increase in VO2peak of 3.7 % (P = 0.04). A very strong correlation could be found between the training data and the performance test.   Conclusions The training intervention was favourable for increasing performance and VO2peak in cycling. Usage of hyperoxia during the training intervention increases the performance. / Syfte och frågeställningar Huvudsyftet med denna studie var att undersöka de longitudinella effekter på prestation i cykling med hjälp av ett polariserat och periodiserat träningsupplägg som var väl övervakat och kontrollerat. Det andra syftet var att undersöka effekten av att använda hyperoxi. De frågeställningar som hjälpte att besvara syftet var: (1) Hur förändras prestationen efter en sex veckors träningsintervention? (2) Hur anpassar sig försökspersonerna till träningsschemat över tid?  (3) Hur förändras prestationen inom grupperna?   Metod 19 manliga och kvinnliga cyklister deltog i studien (13 manliga och 6 kvinnliga), 12 fullföljde hela studien (8 manliga och 4 kvinnliga). Karaktäristiken för de 12 försökspersonerna var: ålder (år) 33.6 ± 6.8, längd (cm) 177 ± 9.1, vikt (kg) 73.4 ± 8.8. Försökspersonerna delades in i hyperoxi (HOT) (n = 6) och normoxi (NOT) (n = 6), studien var dubbelblind. Under sex veckor följde försökspersonerna en kontrollerad polariserad periodisering som inkluderade 15 högintensiva intervallträningspass (HIIT) (3 x 8 min, 3 x 8 + 4 min, 4 x 8 min & 4 x 4 min) på högsta genomförbara intensitet (isoeffort) på cykelergometer. Doseringen av syre administrerades intermittent genom Oxelerate-enheten. Ett 20 min all-out test utfördes som för- och eftertest.   Resultat Hela gruppen (n = 12) ökade signifikant på prestationstestet (W) med 6.4 % (P = 0.002). Den relativa effekten (W/kg) ökade signifikant med 8.2% (P = 0.0011). HOT (n = 6) ökade signifikant på prestationstestet med 8.3% (P = 0.028) och den relativa effekten ökade med 9.4% (P = 0.011). Hela gruppen (n = 12) ökade signifikant i VO2medel under prestationstestet med 4.1 % (P = 0.03) och i det relativa värdet med 5.4 % (P = 0.01). Hela gruppen hade också en signifikant ökning av VO2peak med 3.7 % (P = 0.04). En mycket stark korrelation hittades mellan träningspassdata och prestationstestet.   Slutsats Träningsupplägget är gynnsamt för ökning av prestation och VO2peak i cykling. Användning av hyperoxi under träningsupplägget ökar prestationen.

Les Energies Marines Renouvelables (EMR) se développent aujourd’hui très vite tant au niveau de la recherche amont que de la R&D, et même des premiers démonstrateurs à la mer. Parmi ces EMR, l'énergie des vagues présente un potentiel particulièrement intéressant. Avec une ressource annuelle brute moyenne estimée à 40 kW/m au large de la côte atlantique, le littoral français est plutôt bien exposé. Mais l’exploitation à grande échelle de cette énergie renouvelable ne sera réalisable et pertinente qu'à condition d'une bonne intégration au réseau électrique (qualité) ainsi que d'une gestion et d'un dimensionnement optimisé au sens du coût sur cycle de vie. Une première solution de génération tout électrique pour un houlogénérateur a d’abord été évaluée dans le cadre de la thèse de Marie RUELLAN menée sur le site de Bretagne du laboratoire SATIE (ENS de Cachan). Ces travaux ont mis en évidence le potentiel de viabilité économique de cette chaîne de conversion et ont permis de poser la question du dimensionnement de l’ensemble convertisseur-machine et de soulever les problèmes associés à la qualité de l’énergie produite. Puis une seconde thèse a été menée par Judicaël AUBRY dans la même équipe de recherche. Elle a consisté, entre autres, en l’étude d’une première solution de traitement des fluctuations de la puissance basée sur un système de stockage par supercondensateurs. Une méthodologie de dimensionnement de l’ensemble convertisseur-machine et de gestion de l’énergie stockée fut également élaborée, mais en découplant le dimensionnement et la gestion de la production d’énergie et de ceux de son système de stockage. Le doctorant devra donc : 1. S’approprier les travaux antérieurs réalisés dans le domaine de la récupération de l’énergie des vagues ainsi que les modèles hydrodynamiques et mécaniques réalisés par notre partenaire : le LHEEA de l’Ecole Centrale de Nantes - 2. Résoudre le problème du couplage entre dimensionnement/gestion de la chaîne de conversion et dimensionnement/gestion du système de stockage. 3. Participer à la réalisation d’un banc test à échelle réduite de la chaine électrique et valider expérimentalement les modèles énergétiques du stockage et des convertisseurs statiques associés - 4. Proposer une méthodologie de dimensionnement de la chaine électrique intégrant le stockage et les lois de contrôle préalablement élaborées 5. Déterminer les gains en termes de capacités de stockage obtenus grâce à la mutualisation de la production (parc de machines) et évaluer l’intérêt d’un stockage centralisé - 6. Analyser l’impact sur le réseau d’une production houlogénérée selon divers scenarii, modèles et outils développés par tous les partenaires dans le cadre du projet QUALIPHE. L’exemple traité sera celui de l’Ile d’Yeu (en collaboration avec le SyDEV. / The work of this PhD thesis deals with the minimization of the per-kWh cost of direct-drive wave energy converter, crucial to the economic feasibility of this technology. Despite the simplicity of such a chain (that should provide a better reliability compared to indirect chain), the conversion principle uses an oscillating system (a heaving buoy for example) that induces significant power fluctuations on the production. Without precautions, such fluctuations can lead to: a low global efficiency, an accelerated aging of the fragile electrical components and a failure to respect power quality constraints. To solve these issues, we firstly study the optimization of the direct drive wave energy converter control in order to increase the global energy efficiency (from wave to grid), considering conversion losses and the limit s from the sizing of an electrical chain (maximum force and power). The results point out the effect of the prediction horizon or the mechanical energy into the objective function. Production profiles allow the study of the flicker constraint (due to grid voltage fluctuations) linked notably to the grid characteristics at the connection point. Other models have also been developed to quantify the aging of the most fragile and highly stressed components, namely the energy storage system used for power smoothing (with super capacitors or electrochemical batteries Li-ion) and power semiconductors.Finally, these aging models are used to optimize key design parameters using life-cycle analysis. Moreover, the sizing of the storage system is co-optimized with the smoothing management.