The thesis is focused on design the switching power supply according to Push-pull topology rules. The work describes basic theoretic principles of Push-pull topology with design of circuit and circuit elements.

This Master’s thesis is focused on design of voltage converter’s system operating with supply voltage of batteries. There are selected appropriate types of batteries, converter topologies and modes of their control. The specified output branches are systematically divided into three separate modules. Each module is designed in detail with focus on high efficiency. The modules are implemented and optimized. Parameter of final modules were measured and compared with correctness of design and theoretical assumptions.

This diploma thesis deals with a design layout of the fan power supply that ensures the increase of the efficiency of the heating unit. For usage in the areas without electric power, the power supply is secured by thermoelectric generator. The system has to function on the basis of autonomous system which turns itself on only when necessary. In the introductory part of the paper there is a recherché of thermoelectric generators for general usage. Next it mentions the basic findings in from the field of DC/DC converters for low power applications. In this part attention is given to MPPT algorithm. Furthermore basic knowledge from the field of heat transmission together with its most used elements is described. Subsequently existing applications that increase the effectiveness of heating are mentioned. Their disadvantage however is that they depend on the external source of power supply. The practical part to a large extent covers the analysis of the suitability of the chosen thermoelectric module. For securing of the heat gradient of the generator there was a model created meeting the figures in the manual and there are several simulations in the MATLAB program. Furthermore several measurements of the thermoelectric module took place in order to secure realistic figures. Subsequently a DC/DC converter was chosen. Finally the testing was made on the real composition. In conclusion there is an overall evaluation including the real usage and the economical aspect of the project. The outcomes of the work enable to avoid common mistakes that are part of many specialized articles. The created system is to be used after the adjustment of the cooling to the required aim. At the same time it becomes very effective.

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.

This thesis describes energy consumption and power supplying low-power IoT devices. There is general analysis of current consumption and selecting suitable primary battery cell depends of behavior battery type. The next point is analysis of low-power and high-effectivity DC/DC convertor’s feature. The second part contains available solutions for energy monitoring and current measurement. This thesis also contains design of device for measure these energy consumption, with user application, which interprets measured data.

Master of Science / Department of Electrical and Computer Engineering / Sanjoy Das / Noel Schulz / Electrical power, although convenient form of energy to distribute and use, cannot easily be stored in large quantities economically. Most electrical power generated by utility plants is consumed simultaneously in real time. However, in some cases, energy storage systems become crucial when power generated from sources does not fulfill peak power load demand in a power system or energy storage systems are needed as backup. Due to these reasons, various technologies such as batteries, ultracapacitors (UC), superconducting magnetic energy storage (SEMS) and flywheels are beneficial options for energy storage systems. Shipboard power systems must use one or more energy storage systems in order to backup the existing power system if locally generated power is unavailable. This will lessen the effect of voltage sags on power quality, and improve system reliability. This report mainly focuses on the design of a Boost DC-DC converter and the integration of that converter with a previously designed battery storage model, as well as the effect of varying loads at the end of the converter.

La demande pour des appareils portables multifonctionnels encourage les manufacturiers à intégrer des microsystèmes électromécaniques (MEMS) ou optoélectromécaniques (MOEMS) à leurs produits pour réaliser de nouvelles fonctions ; les pico projecteurs constituent un excellent exemple. Or, dans le but d'utiliser ce type de composants, des tensions de polarisation variant entre 100 V et 300 V sont parfois nécessaires. La génération de ces tensions à partir de la pile de l'appareil exige des convertisseurs continu-continu (DC-DC) miniatures procurant un gain de tension de l'ordre de 100. C'est dans ce contexte général que ce projet réalisé pour Teledyne DALSA, un manufacturier de MEMS et concepteur de circuits intégrés haut voltage, a été réalisé. En intégrant ce circuit à ses circuits de contrôle de MEMS, Teledyne DALSA sera ainsi en mesure de proposer des systèmes plus complets à ses clients. Ce mémoire présente la conception d'un convertisseur DC-DC dans la technologie CO8G CMOS/DMOS haut voltage de Teledyne DALSA. Pour que la solution développée soit assez flexible, le circuit permet un ajustement de la tension de sortie entre 100 V et 300 V pour une puissance de sortie inférieure ou égale à 210 mW à partir d'une tension de batterie entre 2,7 V et 5,5 V. Afin de permettre une longue autonomie des appareils portables, ce projet vise une efficacité de transfert d'énergie de 70 % à la puissance de sortie typique de 75 mW à 220 V. De plus, la solution développée doit être la plus petite possible. À partir de l'état de l'art des circuits de gestion de l'alimentation, ce mémoire présente une conception haut niveau du circuit basée sur des raisonnements et calculs mathématiques simples. Bâtissant sur ces concepts, ce travail détaille la conception des composants de puissance, du circuit de puissance et du contrôleur nécessaire à la réalisation de ce projet. Bien que certaines difficultés, notamment le niveau moyen de l'oscillation de la tension de sortie de 1,6 V, ne permettent pas d'utiliser dès maintenant le circuit développé dans une application commerciale, la solution proposée démontre une amélioration entre 15 % et 43 % de l'efficacité de conversion par rapport au circuit flyback actuel de Teledyne DALSA. De plus, la solution proposée intègre un transistor de puissance 78 % plus petit que les transistors standards disponibles dans la technologie CO8G. Étant donnée l'innovation du circuit présenté au niveau des composants de puissance, du circuit de puissance et du contrôleur, ces résultats de l'implémentation initiale laissent envisager un bon potentiel pour cette architecture après une révision.

The usage of conventional energy applications generates disproportionate emissions of greenhouse gases and the consumption of part of the energy resources available in the world. It has become an important problem which has serious effects on the climatic change. Therefore, it is crucial to reduce these emissions as much as possible. To be able to achieve this, renewable energy technologies must be used instead of conventional energy applications. Solar Photovoltaic (PV) technologies do not release greenhouse gas emissions directly and can save more than 30 million tonnes of carbon per exajoule of electricity generated relative to a natural gas turbine running at 45% efficiency. Shadowing is one of the most important aspects that affects the performance of PV systems. Consequently, many investigations through this topic are being done in order to develop new technologies which mitigate the impact of shadowing during PV production. In order to minimise the impact of shadowing it is desired to be able to predict the performance of a system with PV-modules during shadowing. In this thesis a simulation program for calculating the IV-curve for series connected PV-modules during partial shadowing has been developed and experimentally validated. PV systems modelling and simulation in LTspice environment has been presented and validated by means of a comparative analysis with the experimental results obtained in a set of tests performed in the laboratory of Gävle University. Experimental measurements were carried out in two groups. The first group corresponds with the experiments done in the string of six modules with bypass diodes while the measurements of the second group have been performed on a single PV module at HIG University. The simulation results of both groups demonstrated a remarkable agreement with the experimental data, which means that the model designed at LTspice supposes a very useful tool that can be used to study the performance of PV systems. This tool contributes to the investigations in this topic and it aims to benefit future installations providing a better knowledge of the shading problem. The master’s thesis shows an in-depth description of the required method to design a PV cell, a PV module and a PV array using LTspice IV and the input parameters as well as the needed tests to adjust the models. Moreover, it has been carried out a pedagogical study describing the effect that different shadow configurations have in the performance of solar cells. This study facilitates the understanding of the performance of PV modules under different shadowing effects. Lastly, it has also been discussed the benefits of installing some newer technologies, like DC-DC optimizers or module inverters, to mitigate the shadowing effects. The main conclusion about this topic has been that although most of the times the output power will be increased with the use of optimizers sometimes the optimizer does not present any benefits.

Recent portable electronic technologies require the power management circuit be efficient, small and cost effective. The switched-capacitor (SC) converter provides a trade-off between the efficiency, the size and the cost that is desirable in many of these new portable technologies. This dissertation investigates different circuit techniques and SC converter topologies to make the SC converters fully adapt to the portable system requirements. To make the SC converter efficient over a wide range of input and output voltages, a family of SC power stages with multiple gain ratio (GR) is developed. Multiple GR allows the converter to provide step-down or step-up voltage conversion while increasing the average efficiency of the converter. These power stages are also capable of providing interleaving regulation that has been proved to be effective in reducing the input and the output noise of the converter. Unlike conventional interleaving, the technique developed in this research uses fewer switches and capacitors. The research also contributes in developing circuit techniques such as charge recycling in the bottom plate parasitic capacitors, local gate driving and adaptive body biasing to reduce the power loss in monolithic SC converter implementation. To control the SC power stage for accurate regulation and fast transient response, a control scheme named adaptive gain/pulse control is developed. The research also investigates the use of multipath compensation scheme in SC converters for ultra fast and low noise performance. The techniques and the topologies developed for SC converters in this research can be effectively implemented in the portable devices to reduce cost, and improve efficiency which leads to longer battery life and circuit implementation using smaller areas.

FPGA stands for Field Programmable Gate Array and it is a technology that has been on the rise the last decades. With a decrease in size of the logic elements commercially available products have started to have more built-in functionality in one package and by being reprogrammable makes the system a powerful competitor among its neighbors. FPGA technology in comparison with Digital Signal Processing technology is generally interesting because of the parallelism of the programming that can be made. This allows for more operations in less time. In this thesis a system is developed to control power converters with control signals in high frequency. A previous project is used as a base and a toolchain of new components are implemented to create a new, more generic system. The previous system is evaluated and a new protocol for communication is developed. The toolchain with the necessary control blocks is implemented in Quartus II that includes a timer block, a pulse width modulation block, a PID controller block and a FIR-filter block. The system is used to control a power converter and the result is evaluated.