Recentemente os sistemas de transferência de energia sem fio WPT (do inglês Wireless Power Transfer) têm sido amplamente estudados com o propósito de alimentar eficientemente diversos tipos de cargas através de técnicas específicas, dentre elas destaca-se a transferência capacitiva de potência CPT (do inglês Capacitive Power Transfer) e a transferência indutiva de potência IPT (do inglês Inductive Power Transfer), sendo esta última objeto deste estudo. Em um sistema de transferência indutiva de potência a carga é alimentada através de um transformador fracamente acoplado. Em função do elevado espaçamento entre as bobinas primária e secundária, da ausência de núcleo magnético, ou o emprego do núcleos divididos e separados por um grande entreferro, o transformador apresenta alta reatância de dispersão e baixa reatância de magnetização, o que resulta em elevadas correntes, baixa eficiência e regulação da tensão ruim quando houver variação da carga. Com o intuito de aumentar a eficiência e melhorar a regulação de tensão (ou corrente) são aplicadas compensações capacitivas em ambos os lados do transformador, elevando o número de elementos reativos, o que dificulta a compreensão do seu comportamento. Adicionalmente, as diversas configurações geométricas possíveis para a construção das bobinas dificultam a otimização do projeto de transferência indutiva de potência. Esta dissertação analisa e compara as estratégias de compensação série-série (SS) e série-paralela (SP) sob diversos pontos de vista, identificando pontos de operação relevantes nos quais o sistema atua como uma fonte de corrente ou de tensão em malha aberta, modela os elementos que constituem um sistema de transferência indutiva de potência para alcançar à eficiência requisitada. Adicionalmente este trabalho lista os impactos na fonte e na carga quando do desvio das condições nominais de operação e dá diretrizes que permitem escolher os elementos de um sistema IPT. Na sequência esta dissertação propõe as diretrizes para a construção do transformador com valores predefinidos de fator de qualidade, indutâncias próprias e fator de acoplamento. Por fim, o presente trabalho dimensiona e confecciona alguns sistemas IPT a partir de uma lista de especificações, usando uma metodologia de projeto baseada em fórmulas aproximadas e a valida experimentalmente. / Recently Wireless Power Transfer (WPT) is widely studied in order to efficiently feed many different kinds of loads using specific techniques, such as Capacitive Power Transfer (CPT) and Inductive Power Transfer (IPT). IPT system relies on large air gap and loosely coupled transformer which will be studied in this work. Due to the large separation between the primary and secondary coils, the absence of a magnetic core, or the presence of split cores the transformer presents large leakage inductances, resulting in poor voltage regulation against load variation. Moreover, the low magnetizing inductance results in high magnetizing currents, reducing the overall efficiency. In order to improve the WPT performance, capacitive compensation techniques are applied in both sides of the transformer. Series compensation is commonly used at the primary side of the WPT transformer while Series or Parallel compensation is eligible to the secondary side. In addition, the loosely coupled transformer must be designed, in spite of the complex relationship between the various electrical and geometrical parameters of the coils that complicates the transformer construction and its optimization. This work compares Series-Series and Series-Parallel compensation strategies based on a simple approach, comprehensively highlighting the pro and cons of each one. Also the open loop operation in voltage source and current source modes, and the effect of the gap length for both compensation strategies are discussed. Moreover, the elements that constitute an inductive power transfer system are modeled in order to achieve the required efficiency. This research also proposes some guidance to build the transformer with high figure-of-merit and coupling. Finally, the present work designs and builds few IPT systems that satisfies a set of specifications, based on a simplified design procedure. The proposed design methodology is experimentally validated.

Recentemente os sistemas de transferência de energia sem fio WPT (do inglês Wireless Power Transfer) têm sido amplamente estudados com o propósito de alimentar eficientemente diversos tipos de cargas através de técnicas específicas, dentre elas destaca-se a transferência capacitiva de potência CPT (do inglês Capacitive Power Transfer) e a transferência indutiva de potência IPT (do inglês Inductive Power Transfer), sendo esta última objeto deste estudo. Em um sistema de transferência indutiva de potência a carga é alimentada através de um transformador fracamente acoplado. Em função do elevado espaçamento entre as bobinas primária e secundária, da ausência de núcleo magnético, ou o emprego do núcleos divididos e separados por um grande entreferro, o transformador apresenta alta reatância de dispersão e baixa reatância de magnetização, o que resulta em elevadas correntes, baixa eficiência e regulação da tensão ruim quando houver variação da carga. Com o intuito de aumentar a eficiência e melhorar a regulação de tensão (ou corrente) são aplicadas compensações capacitivas em ambos os lados do transformador, elevando o número de elementos reativos, o que dificulta a compreensão do seu comportamento. Adicionalmente, as diversas configurações geométricas possíveis para a construção das bobinas dificultam a otimização do projeto de transferência indutiva de potência. Esta dissertação analisa e compara as estratégias de compensação série-série (SS) e série-paralela (SP) sob diversos pontos de vista, identificando pontos de operação relevantes nos quais o sistema atua como uma fonte de corrente ou de tensão em malha aberta, modela os elementos que constituem um sistema de transferência indutiva de potência para alcançar à eficiência requisitada. Adicionalmente este trabalho lista os impactos na fonte e na carga quando do desvio das condições nominais de operação e dá diretrizes que permitem escolher os elementos de um sistema IPT. Na sequência esta dissertação propõe as diretrizes para a construção do transformador com valores predefinidos de fator de qualidade, indutâncias próprias e fator de acoplamento. Por fim, o presente trabalho dimensiona e confecciona alguns sistemas IPT a partir de uma lista de especificações, usando uma metodologia de projeto baseada em fórmulas aproximadas e a valida experimentalmente. / Recently Wireless Power Transfer (WPT) is widely studied in order to efficiently feed many different kinds of loads using specific techniques, such as Capacitive Power Transfer (CPT) and Inductive Power Transfer (IPT). IPT system relies on large air gap and loosely coupled transformer which will be studied in this work. Due to the large separation between the primary and secondary coils, the absence of a magnetic core, or the presence of split cores the transformer presents large leakage inductances, resulting in poor voltage regulation against load variation. Moreover, the low magnetizing inductance results in high magnetizing currents, reducing the overall efficiency. In order to improve the WPT performance, capacitive compensation techniques are applied in both sides of the transformer. Series compensation is commonly used at the primary side of the WPT transformer while Series or Parallel compensation is eligible to the secondary side. In addition, the loosely coupled transformer must be designed, in spite of the complex relationship between the various electrical and geometrical parameters of the coils that complicates the transformer construction and its optimization. This work compares Series-Series and Series-Parallel compensation strategies based on a simple approach, comprehensively highlighting the pro and cons of each one. Also the open loop operation in voltage source and current source modes, and the effect of the gap length for both compensation strategies are discussed. Moreover, the elements that constitute an inductive power transfer system are modeled in order to achieve the required efficiency. This research also proposes some guidance to build the transformer with high figure-of-merit and coupling. Finally, the present work designs and builds few IPT systems that satisfies a set of specifications, based on a simplified design procedure. The proposed design methodology is experimentally validated.

The wireless sensor network (WSN) is increasingly used in many areas nowadays. It can be applied to provide the solutions to environmental problems, help increasing security and safety systems, and make the detection of the problems more efficient, e.g. the earthquake or tidal wave, which will harmful to humans. The WNS is durable and resistant to all types of terrain and climate, but while the WSN system is more and more widespread, one of the obstacles hindering the growth of this technology and the demand for WSN applications is the limited battery lifespan. Consequently, there is a significant requirement for techniques for prolonging the battery’s lifespan. Therefore, one potential solution is to use alternative energy sources combined with the sensor nodes in WSN, specifically energy harvesting from existing environmental sources. This research project reviews the characteristics of each kind of energy harvesting, understanding the various energy sources (solar energy, vibration energy and wind power), including wireless power transfer (WPT) by using electromagnetic (EM) radiation energy transfer or RF radio-frequency emission and magnetic coupled energy transfer. They are adopted for extending node’s life in the WSN, based on published information. Then it compares these diverse alternative energy methods and identifies for the most suitable energy harvesting method for application to wireless sensor nodes in order to prolong the lifespan of the battery. The major findings from the researcher include that wireless power transfer energy harvesting (WPT) using the magnetic field is the most appropriate tool for extending the lifespan of the WSN system. In addition, the author also designed an experiment to test this alternative energy, achieving by modelling the wireless power transfer with four coils. From the experimental results, it can be seen that the WPT technique using energy harvesting with magnetic inductive source can be applied to prolong the lifespan of the WSN system.

<div>Electric vehicles (EVs) face a major issue before becoming the norm of society, that is, their lack of range when it comes to long trips. Fast charging stations are a good step forward to help make it simpler for EVs, but it is still not as convenient when compared to vehicles with an internal combustion engine (ICE). Plenty of infrastructure changes have been proposed in the literature attempting to tackle this issue, but they typically tend to be either an expensive solution or a difficult practical implementation.</div><div> </div><div> This dissertation presents two solutions to help increase the range of EVs: a novel wireless charging method and a multi-motor architecture for EVs. The first proposed solution involves the ability for EVs to charge while en route from another vehicle, which will be referred to from here on as vehicle-to-vehicle recharging (VVR). The aim of this system is to bring an innovative way for EVs to charge their battery without getting off route on a highway. The electric vehicle can request such a service from a designated charger vehicle on demand and receive electric power wirelessly while en route. The vehicles that provide energy (charger vehicles) through wireless power transfer (WPT) only need to be semi-autonomous in order to ``engage'' or ``disengage'' during a trip. Also, a novel method for wireless power transfer will be presented, where the emitter (TX) or receiver (RX) pads can change angles to improve the efficiency of power transmission. This type of WPT system would be suitable for the VVR system presented in this dissertation, along with other applications.</div><div> </div><div> The second solution presented here will be an architecture for EVs with three or more different electric motors to help prolong the state of charge (SOC) of the battery. The key here is to use motors with different high efficiency regions. The proposed control algorithm optimizes the use of the motors on-board to keep them running in their most efficient regions. With this architecture, the powertrain would see a combined efficiency map that incorporates the best operating points of the motors. Therefore, the proposed architecture will allow the EV to operate with a higher range for a given battery capacity.</div><div> </div><div> The state-of-the-art is divided into four subsections relevant to the proposed solutions and where most of the innovations to reduce the burden of charging EVs can be found: (1) infrastructure changes, (2) device level innovations, (3) autonomous vehicles, and (4) electric vehicle architectures. The infrastructure changes highlight some of the proposed systems that aim to help EVs become a convenient solution to the public. Device level innovations covers some of the literature on technology that addresses EVs in terms of WPT. The autonomous vehicle subsection covers the importance of such technology in terms of safety and reliability, that could be implemented on the VVR system. Finally, the EV architectures covers the current typologies used in EVs. Furthermore, modeling, analysis, and simulation is presented to validate the feasibility of the proposed VVR system, the WPT system, and the multi-motor architecture for EVs.</div>

Wireless powered communication (WPC) is an emerging paradigm where wireless devices are powered over the air while exchanging information with them. This technology is attractive for various wireless applications, including classical radio-frequency identification (RFID) systems, implantable sensors, environmental sensing as found in agriculture and forestry, and simultaneous charging and telemetry communications for electric vehicles. While recent studies have shown that inductive coupling provides a more energy-efficient and robust channel for short and middle-range wireless transmission, most of the previous analyses on WPC have been limited to far-field transmission models. To this end, this work provides a comprehensive framework to design and analyze WPC over inductively coupled circuits. We consider three problems, namely, wireless power transfer (WPT), simultaneous wireless information and power transfer (SWIPT), and wireless powered communication network (WPCN) using multiple coupled coils. Each configuration is modeled by an abstract circuit model in which various effects, including mutual coupling and parasitic elements, are captured by a small number of measurable parameters. This technique allows us to not only eliminate the need for solving the circuit but also apply well-known signal processing techniques such as beamforming and channel estimation to inductively coupled models. For each of the three models, we derive the properties of the optimal source signal. In addition, we propose methods to design the load impedance of WPCN by taking into account the nonlinear effects due to impedance mismatches in the circuits.

<p>Lyophilization is the process of controllably removing the water content from a material with the objective of increasing its stability and, hence, its shelf life. This dissertation addresses two of the challenges faced by lyophilization, namely continuous temperature-monitoring and lengthy primary drying step.</p> <p>Continuous temperature monitoring of the product is imperative to a successful lyophilization process. It is more efficient to employ wireless temperature sensors rather than the conventional thermocouples. These wireless sensors need to keep a low profile that does not allow bulky battery attachment. Therefore, harvesting microwave energy is an excellent practice to power these sensors. Energy harvesting problem is twofold. One, designing an efficient flexible power-harvester (rectenna). To address this problem, we present a flexible rectenna with superior efficiency. While doing so, we establish the design procedure that can be followed for similar designs. Two, delivering sufficient power to the rectenna location inside the chamber. To address this problem, we propose two electromagnetic techniques, namely the statistical electromagnetics (SEM) and the electromagnetic time reversal (EMTR). These enable uniform power distribution and higher total efficiency.</p> As for the lengthy primary drying, to speed up the process, we propose RF-heating as a replacement for conventional heating. We establish a procedure for frequency selection based on the material under lyophilization and the geometrical properties of the freeze-drier’s chamber. The same techniques, SEM and EMTR are used. We conduct RF-assisted lyophilization processes based on SEM on different pharmaceutical bare excipients and on Myoglobin in four different excipients. The results confirm the superiority of the proposed technique in terms of drying time and heating uniformity.

Le sujet de thèse abordé dans ce mémoire s'inscrit dans la thématique du LE²P sur l'autonomie énergétique des réseaux de capteurs. Ce travail est axé sur la partie réception et redressement du transfert de l'énergie sans fil pour l'apport d'énergie à des capteurs nomades. Ce procédé n'est pas nouveau et prend son origine dans les années 1950. Les connaissances dans l'appréhension de ce processus sont nombreuses pour certains guides d'onde tels que le microruban. Mais la nécessité de perçages dans ces structures de guide d'onde peut être contraignante et causer des disparités dans une chaîne de construction. Ceci a motivé les travaux présentés dans ce mémoire qui utilise une technologie de guide d'onde coplanaire (CPW) peu exploitée. Ainsi, la conception d'un tel dispositif passe par la maîtrise d'un point de vue conceptuel et expérimental de cette technologie. La démarche consiste à utiliser ce guide d'onde coplanaire en minimisant les effets négatifs que peut engendrer ce dernier, pour s'abroger du besoin de perçage et faciliter la réalisation des dispositifs de redressement en limitant le nombre d'interactions humaines. / The thesis subject dealt in this report lies in the LE²P framework on the energy sustainability of wireless sensor network. This work is dedicated to the reception and rectifying part of wireless power transfer to give energy sustainability to nodes in a sensor network. This process is not new and originate from the years 1950. The behavior of this process is since well-known in several waveguide such technology as microstrip. But the need of drill in those waveguide circuit may be inconvenient and lead to discrepancy from one circuit to another. This was the motivational keystone to the work address in this report which uses coplanar waveguide (CPW) over microstrip. The conception of such devices goes through a good conceptual and experimental understanding of the waveguide technology. The approach in this document consists of using coplanar waveguide while minimizing its drawbacks, in order to avoid drilling in the substrate and ease the realization of the rectifying part by limiting the human interaction.

<div> <div> <div> <div> <p>This dissertation presents and develops a novel method of wireless power transfer that relies on electromagnetic coupling from open-wire transmission lines instead of tra- ditional methods. Wireless power transfer techniques are being rapidly pursued in re- search currently due to the potential utility of powering devices over the air instead of with direct electrical connections. Uses for such techniques include an array of ap- plications from consumer electronics, to medical devices, to cars and UAVs. While con- ventional wireless power transfer techniques exist, it is shown here that open-wire trans- mission line methods present distinct advantages for certain applications. In particular, wireless power transfer using Goubau and twin-lead line architectures will be conceptual- ized and investigated in terms of their theory, design, and efficiency performance. Fur- ther, a circuit model theory will be developed in this work to provide a generalized for- mulation for open-wire-line wireless power transfer analysis. Additionally, receiver de- sign techniques will be outlined and geometries based on metamaterial principles will be pursued in order to achieve receiver miniaturization and access the applications this af- fords. </p> </div> </div> </div> </div>

This dissertation is particularly focused on a novel approach of a wirelessly powered neuromodulation system for chronic patients. The inductively coupled transmitter (TX) and receiver (RX) coils are designed through optimization to achieve maximum efficiency. A power management unit (PMU) consisting of a voltage rectifier, voltage regulator along with a stimulation circuitry is also designed to provide pulse stimulation to genetically modified neurons. For continuous health monitoring purposes, the response from the brain due to stimulation needs to be recorded and transmitted wirelessly outside the brain for analysis. A low-power high-data duty-cycled impulse-radio ultra-wideband (IR-UWB) transmitter is designed and implemented using the standard CMOS process. Another focus of this dissertation is the design of a reverse electrowetting-on-dielectric (REWOD) based energy harvesting circuit for wearable sensor applications which is capable of generating a very low-frequency signal from motion activity such a walking, running, jogging, etc. A commercial off-the-shelf (COTS) based and on-chip based energy harvesting circuit is designed for very low-frequency signals. The experimental results show promising progress towards the advancement in the wirelessly powered neuromodulation system and building the self-powered wearable sensor.

<p dir="ltr">Electric roadways (ERs) represent a new paradigm for electrified transportation that is</p><p dir="ltr">enabled by the emerging dynamic (in-motion) wireless power transfer technology. Large-scale</p><p dir="ltr">integration of DWPT systems into power grids can pose a problem due to its high-power</p><p dir="ltr">requirements, significant number of power electronic converters and spatial concentration.</p><p dir="ltr">Despite their potential magnitude, the operational impacts of DWPT on the power grid have</p><p dir="ltr">not been fully studied in the literature. This dissertation contributes to our understanding</p><p dir="ltr">of how ERs could be successfully integrated with the electric power system at a diverse range</p><p dir="ltr">of spatial and temporal levels.</p><p dir="ltr">On a macroscopic level, a framework for assessing the financial viability of ERs is proposed.</p><p dir="ltr">Annual ER load estimations from traffic flow models of electric vehicles are used to</p><p dir="ltr">generate energy forecasts and carry out a financial evaluation. These models are also used to</p><p dir="ltr">plan distribution system capacity expansion. On a mesoscopic level, a data-driven design of</p><p dir="ltr">ERs and their interconnection with the distribution grid is presented. A data-based stochastic</p><p dir="ltr">traffic flow model is developed and used for designing the interconnection of the DWPT</p><p dir="ltr">system with the distribution grid ensuring adequate power transmission to high penetration</p><p dir="ltr">levels of heavy-duty trucks. The model is also used for conducting a series of quasi-steady</p><p dir="ltr">state studies on the power distribution system. On a microscopic level, a methodology for</p><p dir="ltr">modeling ER systems for time-domain simulations is proposed. Dynamic component models</p><p dir="ltr">are developed for the DWPT system. Power electronics are modeled using average-value</p><p dir="ltr">representations and integrated with models of the distribution grid. The models are used for</p><p dir="ltr">time-domain system simulations, transient analysis, fault analysis and power quality studies.</p><p dir="ltr">Theoretical analysis as well as numerical case studies and simulations of the proposed</p><p dir="ltr">methodologies are presented.</p>