This thesis provides a basic overview of the ancillary services in a transmission system. It summarizes changes regarding the implementation of European directives SOGL and EBGL. It describes in detail a portfolio of non-frequency ancillary services used in the distribution systems. It evaluates the demand of E.ON distribution system potential for those services in particular locations. Practical part is focused on a potential of reactive power management in this distribution area. It evaluates reactive power flow into transmission system and indicates the most critical substations. This thesis also covers analysis of existing resources in this distribution area and assign their possible potential in reactive power management.

Tato diplomová práce se zabývá vývojem autonomního zdroje elektrické energie založeného na MEMS termoelektrickém generátoru. Uvažovaný generátor bude následně použit pro napájení autonomní senzorické jednotky pro letecké aplikace. Systémový pohled na autonomní senzorickou jednotku zahrnuje senzor se zpracováním a přenosem dat, energy harvester (termoelektrický generátor), power management, akumulační prvek a autodiagnostiku. Všechny výše uvedené komponenty jsou v práci podrobně popsány. V úvodu práce je provedena široká rešerše existujících termoelektrických generátorů pro letecké aplikace. Následně jsou popsány základní teoretické poznatky z oblasti DC/DC měničů pro energy harvesting. Zvláštní pozornost je věnována metodám MPPT (Maximum Power Point Tracking). Jako základ pro vývoj napájení autonomní senzorické jednotky bylo provedeno množství simulací za pomoci nástroje MATLAB/Simulink Simscape. Pro identifikaci prametrů modelu posloužilo měření na speciálním přípravku. Praktická implementace teoreticky popsaných problémů je provedena na k tomuto účelu navrženém technologickém demonstrátoru. Závěrem je zhodnocena reálná využitelnost navržené technologie pro finální aplikaci v leteckém průmyslu.

Increase in the awareness environmental conservation is leading the automotive industry into the adaptation of alternatively fueled vehicles. Electric, Fuel-Cell as well as Hybrid-Electric vehicles focus on this research area with aim to efficiently utilize vehicle powertrain as the first step. Energy and Power Management System control strategies play vital role in improving efficiency of any hybrid propulsion system. However, these control strategies are sensitive to the dynamics of the powertrain components used in the given system. A kinematic mathematical model for Plug-in Hybrid Electric Vehicle (PHEV) has been developed in this study and is further optimized by determining optimal power management strategy for minimal fuel consumption as well as NOx emissions while executing a set drive cycle. A multi-objective optimization using weighted sum formulation is needed in order to observe the trade-off between the optimized objectives. Particle Swarm Optimization (PSO) algorithm has been used in this research, to determine the trade-off curve between fuel and NOx. In performing these optimizations, the control signal consisting of engine speed and reference battery SOC trajectory for a 2-hour cycle is used as the controllable decision parameter input directly from the optimizer. Each element of the control signal was split into 50 distinct points representing the full 2 hours, giving slightly less than 2.5 minutes per point, noting that the values used in the model are interpolated between the points for each time step. With the control signal consisting of 2 distinct signals, speed and SOC trajectory, as 50 element time variant signals, a multidimensional problem was formulated for the optimizer. Novel approaches to balance the optimizer exploration and convergence, as well as seeding techniques are suggested to solve the optimal control problem. The optimization of each involved individual runs at 5 different weight levels with the resulting cost populations being compiled together to visually represent with the help of Pareto front development. The obtained results of simulations and optimization are presented involving performances of individual components of the PHEV powertrain as well as the optimized PMS strategy to follow for given drive cycle. Observations of the trade-off is discussed in the case of Multi-Objective Optimizations.

Energy harvesting is identified as a promising alternative solution for powering implantable biosensors. It can completely replace the batteries, which are introducing many limitations, and it enables the development of self-powered implantable biosensors. An interface circuit is necessary to correct for differences in the voltage and power levels provided by an energy harvesting device from one side, and required by biosensor circuits from another. This thesis investigates the available energy harvesting sources within the human body, selects the most suitable one and proposes the power management unit (PMU), which serves as an interface between a harvester and biosensor circuits. The PMU targets the efficient power transfer from the selected source to the implantable biosensor circuits. Based on the investigation of potential energy harvesting sources, a thermoelectric energy harvester is selected. It can provide relatively high power density of 100 μW/cm2 at very low temperature difference available in the human body. Additionally, a thermoelectric energy harvester is miniature, biocompatible, and it has an unlimited lifetime. A power management system architecture for thermoelectric energy harvesters is proposed. The input converter, which is the critical block of the PMU, is implemented as a boost converter with an external inductor. A detailed analysis of all potential losses within the boost converter is conducted to estimate their influence on the conversion efficiency. The analysis showed that the inevitable conduction and switching losses can be reduced by the proper sizing of the converter’s switches and that the synchronization losses can be almost completely eliminated by an efficient control circuit. Additionally, usually neglected dead time losses are proved to have a significant impact in implantable applications, in which they can reduce the efficiency with more than 2%. An ultra low power control circuit for the boost converter is proposed. The control is utilizing zero-current switching (ZCS) and zero-voltage switching (ZVS) techniques to eliminate the synchronization losses and enhance the efficiency of the boost converter. The control circuit consumes an average power of only 620 nW. The boost converter driven by the proposed control achieves the peak efficiency higher than 80% and can operate with harvested power below 5 μW. For high voltage conversion ratios, the proposed boost converter/control combination demonstrates significant efficiency improvement compared to state-of-the-art solutions. / <p>QC 20150413</p>

No description available.

Emerging mobile platforms integrate heterogeneous, multicore processors to efficiently deal with the heterogeneity of data (in magnitude, type, and quality). The main goal is to achieve a high degree of energy-proportionality which corresponds with the nature and fluctuation of mobile workloads. Most existing power and energy consumption analyses of these architectures rely on simulation or static benchmarks neither of which truly reflects the type of workload the processors handle in reality. By contrast, we generate two types of stochastic workloads and employ four types of dynamic voltage and frequency scaling (DVFS) policies to investigate the energy proportionality and the dynamic power consumption characteristics of a heterogeneous processor architecture when operating in different configurations. The analysis illustrates, both qualitatively and quantitatively, that knowledge of the statistics of the incoming workload is critical to determine the appropriate processor configuration.

The aim of this thesis is to explore the possibility of a dual-purpose electric vehicle. The vehicle should be able to be used for both commuting and racing. It also aims to describe different power limiting methods and their effect on performance. Lastly it hopes to see if the Swedish laws, as written today are reasonable. An electric longboard has been constructed for this purpose and several tests have been performed. A list of goals were set up for the board prototype. These included power output, running time, and that the board should have an audible warning device. The findings demonstrated that all tested power limiting methods worked and that the “Simple power limiting” method provided quickest movement over a fixed distance. Most of the goals were met by the prototype and the board’s two modes worked as planned. While the law is reasonable it can be improved to cover the diversity of electric vehicles. Further work may include better measurements and implementation of a dual microcontroller system. / Syftet med detta arbete är att testa möjligheten med ett två-läges personligt fordon. Fordonenet ska kunna användas för både pendling och tävling. Arbetet har även testat olika energilimeteringsmetoder samt undersökt hur dessa metoder påverkar prestandan. Arbetet har även försökt besvara frågan om det svenska lagarna, som det är skrivna idag, är lämpliga. En elektrisk longboard har konstruerats och flera test utförts. Ett antal målsättningar har definerats för prototypen. Dessa inkluderar: effekt, körtid och att brädan bör ha en ringklocka. Resultaten visar att alla metoder fungerade och att “Simple power limiting” var den som gav snabbast rörelse över den bestämda sträckan. Det flesta av målen nåddes av prototypen och brädans två lägen fungerade som tänkt. Dagens lagar är rimliga men kan förbättras för att täcka mångfalden av elektriska fordon. Framtida arbete kan inkludera bättre mätningar och implementation av ett system med två mikrokontroller.

The aim of this thesis is to explore the possibility of adual-purpose electric vehicle. The vehicle should be ableto be used for both commuting and racing. It also aims todescribe different power limiting methods and their effecton performance. Lastly it hopes to see if the Swedish laws,as written today are reasonable. An electric longboard hasbeen constructed for this purpose and several tests havebeen performed.A list of goals were set up for the board prototype. Theseincluded power output, running time, and that the boardshould have an audible warning device.The findings demonstrated that all tested power limitingmethods worked and that the “Simple power limiting” methodprovided quickest movement over a fixed distance. Most ofthe goals were met by the prototype and the board’s twomodes worked as planned. While the law is reasonable itcan be improved to cover the diversity of electric vehicles.Further work may include better measurements and implementationof a dual microcontroller system. / Syftet med detta arbete är att testa möjligheten med etttvå-läges personligt fordon. Fordonenet ska kunna användasför både pendling och tävling. Arbetet har även testat olikaenergilimeteringsmetoder samt undersökt hur dessa metoderpåverkar prestandan. Arbetet har även försökt besvarafrågan om det svenska lagarna, som det är skrivna idag, ärlämpliga. En elektrisk longboard har konstruerats och fleratest utförts.Ett antal målsättningar har definerats för prototypen. Dessainkluderar: effekt, körtid och att brädan bör ha en ringklocka.Resultaten visar att alla metoder fungerade och att “Simplepower limiting” var den som gav snabbast rörelse över denbestämda sträckan. Det flesta av målen nåddes av prototypenoch brädans två lägen fungerade som tänkt. Dagens lagarär rimliga men kan förbättras för att täcka mångfaldenav elektriska fordon. Framtida arbete kan inkludera bättremätningar och implementation av ett system med två mikrokontroller.

No description available.

No description available.