Dissertations / Theses on the topic 'WIRELESS POWER SYSTEM'
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1
Jenkinson, Ashley. "Long range wireless power monitoring system." Thesis, Jenkinson, Ashley (2012) Long range wireless power monitoring system. Other thesis, Murdoch University, 2012. https://researchrepository.murdoch.edu.au/id/eprint/13121/.
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This thesis examines the design, construction and implementation of a microcontroller-based long range wireless power monitoring system, suitable for both domestic and industrial use. At its core, the system is based on a number of PICAXE 20X2 microcontrollers and a pair of XBee Pro wireless modules, which are capable of wireless communication to distances exceeding 1.5km.
The Long Range Wireless Power Monitoring system is capable of galvanically isolated single and three-phase current and voltage measurements and is able to calculate real power, apparent power and power factor. The results can be displayed numerically or graphically on a Graphical Liquid Crystal Display. In addition to this, the system has the ability to log usage to an external USB Flash device, allowing for later analysis and for the building of a usage history library.
The Long Range Wireless Power Monitor is equally proficient at measuring power consumption of devices, or power generation from sources such as photovoltaic cells or wind turbines. In the example of power consumption, usage costs are calculated from user-defined tariffs. Conversely, for generation, the income from power generated is calculated.
At the completion of this project, the Wireless Power Monitor is capable of being deployed for use as a fully working prototype. In addition to this, the system provides a solid basis for future adaptation or expansion and due to its open source software can be easily modified for use in specific applications.
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Heffernan, Travis Jade. "Metamaterial Enhanced Wireless Power Transmission System." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1069.
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Nikolai Tesla's revolutionary experiments demonstrated the possible benefits of transmitting power wirelessly as early as 1891. Applications for the military, consumers, emergency personnel, remote sensors, and others use Tesla’s discovery of wireless power. Wireless power transmission (WPT) has the potential to be a common source of consumable energy, but it will only receive serious consideration if the transmit and receive systems are extremely efficient and capable of delivering usable amounts of power. Research has been conducted to improve the efficiency and performance of nearly every aspect of WPT systems, but the relatively new field of metamaterials (MTMs) has yet to play a dominate role in improving system performance. A gradient index (GRIN) MTM lens was designed using Ansoft’s High Frequency Structure Simulator (HFSS) to improve antenna gain and thereby increase WPT system performance. A simple WPT demonstration system using microstrip patch antennas (MPAs) confirmed the benefits of the GRIN MTM lens. The WPT demonstration system, MPAs, and GRIN MTM lens were constructed and experimentally tested near 2.45 GHz. The theoretical and experimental gain improvement of the MPA due to the GRIN MTM lens is 5.91 dB and 7.06 dB, respectively.
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Wang, Yan. "Low power design for wireless communication system /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202003%20WANG.
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Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003.Includes bibliographical references (leaves 171-179). Also available in electronic version. Access restricted to campus users.
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Miura, Takeshi. "Study of Microwave Power Receiving System for Wireless Power Transmission." 京都大学 (Kyoto University), 2000. http://hdl.handle.net/2433/180901.
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Liu, Feng. "Lifetime maximization through adaptive power allocation in reconfigurable system design for wireless systems /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?ECED%202009%20LIU.
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Lee, Hyung-Min. "A power-efficient wireless neural stimulating system with inductive power transmission." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53449.
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The objective of the proposed research is to advance the power efficiency of wireless neural stimulating systems in inductively powered implantable medical devices (IMD). Several innovative system- and circuit-level techniques are proposed towards the development of power-management circuits and wireless neural stimulating systems with inductive power transmission to improve the overall stimulation power efficiency.
Neural stimulating IMDs have been proven as effective therapies to alleviate neurological diseases, while requiring high power and performance for more efficacious treatments. Therefore, power-management circuits and neural stimulators in IMDs should have high power efficiencies to operate with smaller received power from a larger distance. Neural stimulating systems are also required to have high stimulation efficacy for activating the target tissue with a minimum amount of energy, while ensuring charge-balanced stimulation. These features provide several advantages such as a long battery life in an external power transmitter, extended-range inductive power transfer, efficacious and safe stimulation, and less tissue damage from overheating.
The proposed research presents several approaches to design and implement the power-efficient wireless neural stimulating IMDs: 1) optimized power-management circuits for inductively powered biomedical microsystems, 2) a power-efficient neural stimulating system with adaptive supply control, and 3) a wireless switched-capacitor stimulation (SCS) system, which is a combination structure of the power-management circuits and neural stimulator, to maximize both stimulator efficiency (before electrodes) and stimulus efficacy (after electrodes).
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Yang, Bo. "High Power Microwave Wireless Power Transmission System with Phase-Controlled Magnetrons." Kyoto University, 2020. http://hdl.handle.net/2433/259739.
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Yeh, David Alexander. "Multi-gigabit low-power wireless CMOS demodulator." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/41168.
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This dissertation presents system and circuit development of the low-power multi-gigabit CMOS demodulator using analog and mixed demodulation techniques. In addition, critical building blocks of the low-power analog quadrature front-ends are designed and implemented using 90 nm CMOS with a targeted compatibility to the traditional demodulator architecture. It exhibits an IF-to-baseband conversion gain of 25 dB with 1.8 GHz of baseband bandwidth and a dynamic range of 23 dB while consuming only 46 mW from a 1 V supply voltage. Several different demodulators using analog signal processor (ASP) are implemented: (1) an ultra-low power non-coherent ASK demodulator is measured to demodulate a maximum speed of 3 Gbps while consuming 32 mW from 1.8 V supply; (2) a mere addition of 7.5 mW to the aforementioned analog quadrature front-end enables a maximum speed of 2.5 Gbps non-coherent ASK demodulation with an improved minimum sensitivity of -38 dBm; (3) a robust coherent BPSK demodulator is shown to achieve a maximum speed of 3.5 Gbps based on the same analog quadrature front-end with only additional 7 mW. Furthermore, an innovative seamless handover mechanism between ASP and PLL is designed and implemented to improve the frequency acquisition time of the coherent BPSK demodulator. These demodulator designs have been proven to be feasible and are integrated in a 60 GHz wireless receiver. The system has been realized in a product prototype and used to stream HD video as well as transfer large multi-media files at multi-gigabit speed.
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Patel, Ketan B. (Ketan Kumar Balubhai) 1975. "Ultra low-power wireless sensor demonstration system : design of a wireless base station." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/86434.
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Lu, Shili. "Stochastic power control for wireless networks: Probabilistic QoS measures." Thesis, University of Ottawa (Canada), 2005. http://hdl.handle.net/10393/26964.
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For wireless network systems, iterative power control algorithms have been proposed to minimize the transmission power, while maintaining reliable communication and base stations. However, since the measurements are random, the channel characteristics always are described by Stochastic Differential Equations (SDE). Based on the stochastic approximation methods, and using time-varying step size sequences, we can get an approximation algorithm to reach an optimal power allocation.
After the study of optimal power allocation, the probabilistic Quality of Service (QoS) measures are introduced to evaluate the performance of any control strategy. It provides tight bounds that relate to the probability of failure in achieving the desired QoS requirements.
This thesis addresses mobile systems consisting of M transmitters and M receivers, which are subject to motion, and their power is described by SDE. The optimal power control problem is formulated, and the outage probability corresponding to a desired QoS requirements is computed using Moment Generating Function (MGF).
Numerical results show that each user needs only to know its own channel gain and its own output assigned by the base station to update the transmitter power in order to maintain a desired Signal to Interference Ratio (SIR) and QoS requirement at the receiver.
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O'Brien, Kathleen. "Inductively coupled radio frequency power transmission system for wireless systems and devices /." Aachen : Shaker, 2007. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=015959229&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Hu, Yiwei. "Development of wireless network system on a power wheelchair." Thesis, University of Canterbury. Mechanical Engineering, 2012. http://hdl.handle.net/10092/7661.
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The development of wireless communication technology offers new opportunities to enhance the functionalities of mobility systems (e.g. powers wheelchairs and robots). This thesis presents new hardware and software architecture to offer ease of user control and power efficiency to an autonomous mobility system by using Wireless Networked Control (WSC). A wireless network is applied to perform both environment sensing and user control. The development will be demonstrated through a case study on a power wheelchair.
The challenge in the development of such a wireless solution is to accomplish a set of system activities (e.g. system initialization, system monitoring, power management) under different circumstances within a dynamic wireless network without sacrificing flexibility, energy-efficiency, or reliability.
The optimal way to achieve this is to design a protocol stack orientated to the demand of a specific system with cross-layer optimization. However, it requires significant design effort. In this thesis, a wireless network is constructed by utilizing a commercial-of-the-shelf (COTS) protocol. The development focuses on system integration and Application Layer. This accelerates the development progress with the benefits of cost effectiveness and less burden on protocol design. However, the COTS protocol is not able to provide a solution with maximum efficiency, because that the development of a COTS protocol is constrained by many factors. For example, the low layers of a COTS protocol are usually not available for customization due to the license issue.
The aim of this project is to develop a wireless platform to enable wireless functional devices to be added into a mobile system. The main benefit of such a wireless network system (WNS) is to allow new modules to be readily incorporated into the mobility system, which otherwise are difficult, because either, the physical wiring is prohibitive or the current system does not allow the signals to be processed.
The strategy for developing such a wireless network with desired functionalities is to build both identity management module and power management module based upon system design and Application Layer development. The identity management module allows the system to perform self-construction and self-maintenance and the power management offers high power efficiency. These two modules are developed independently and integrated into an autonomous control loop. Transitions between different modules are achieved by handshaking protocols. The advantage of such a strategy is the ease for customization and extension. The infrastructure includes gateway, Log-in system and radio frequency (RF) platform.
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Lukashov, Stanislav V. "A self-tuning 100 watt wireless power transfer system." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113128.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 81-83).
This thesis presents a new method of controlling wireless power transfer suitable for highly resonant magnetically coupled systems. An application of this system is unattended autonomous operation such as recharging of autonomous underwater vehicles or underwater sensor networks. Special attention is given to maximizing power transfer even when there may be spatial variations in transfer distance, which shifts the resonance peak frequency and hence requires automated control. An automated system comprised of a 100 watt switching power amplifier coupled to a frequency controller is designed and implemented. The desired operating frequency is determined by quantification of the real-time AC power supplied to the resonant transmitter. The control system is preset to select operation at either of two selectable modes inherent to the resonant structure. The implemented system can operate underwater, requires only DC voltage inputs and operates over a range of distances while self-tuning to peak power transfer.
by Stanislav V. Lukashov.
M. Eng.
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Zhang, Xuejun. "An improved outphasing power amplifier system for wireless communications /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2001. http://wwwlib.umi.com/cr/ucsd/fullcit?p3029646.
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Tam, Wai Kei. "Home appliances control system incorporating wireless communication and power line." Thesis, University of Macau, 2006. http://umaclib3.umac.mo/record=b1636548.
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Wang, Ce. "Study on Novel Rectifiers for Microwave Wireless Power Transfer System." Kyoto University, 2020. http://hdl.handle.net/2433/253503.
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Feng, Junjie. "6.78MHz Omnidirectional Wireless Power Transfer System for Portable Devices Application." Diss., Virginia Tech, 2021. http://hdl.handle.net/10919/101839.
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Wireless power transfer (WPT) with loosely coupled coils is a promising solution to deliver power to a battery in a variety of applications. Due to its convenience, wireless power transfer technology has become popular in consumer electronics. Thus far, the majority of the coupled coils in these systems are planar structure, and the magnetic field induced by the transmitter coil is in one direction, meaning that the energy power transfer capability degrades greatly when there is some angle misalignment between the coupled coils.
To improve the charging flexibility, a three–dimensional (3D) coils structure is proposed to transfer energy in different directions. With appropriate modulation current flowing through each transmitter coil, the magnetic field rotates in different directions and covers all the directions in 3D space. With omnidirectional magnetic field, the charging platform can provide energy transfer in any direction; therefore, the angle alignment between the transmitter coil and receiver coil is no longer needed.
Compensation networks are normally used to improve the power transfer capability of a WPT system with loosely coupled coils. The resonant circuits, formed by the loosely coupled coils and external compensation inductors or capacitors, are crucial in the converter design. In WPT system, the coupling coefficient between the transmitting coil and the receiving coil is subject to the receiver's positioning. The variable coupling condition is a big challenge to the resonant topology selection. The detailed requirements of the resonant converter in an omnidirectional WPT system are identified as follows: 1). coupling independent resonant frequency; 2). load independent output voltage; 3). load independent transmitter coil current; 4). maximum efficiency power transfer; 5). soft switching of active devices. A LCCL-LC resonant converter is derived to satisfy all of the five requirements.
In consumer electronics applications, Megahertz (MHz) WPT systems are used to improve the charging spatial freedom. 6.78 MHz is selected as the system operation in AirFuel standard, a wireless charging standard for commercial electronics. The zero voltage switching (ZVS) operation of the switching devices is essential in reducing the switching loss and the switching related electromagnetic interference (EMI) issue in a MHz system; therefore, a comprehensive evaluation of ZVS condition in an omnidirectional WPT system is performed. And a design methodology of the LCCL-LC converter to achieve ZVS operation is proposed.
The big hurdle of the WPT technology is the safety issue related to human exposure of electromagnetic fields (EMF). A double layer shield structure, including a magnetic layer and a conductive layer, is proposed in a three dimensional charging setup to reduce the stray magnetic field level. A parametric analysis of the double shield structure is conducted to improve the attenuation capability of the shielding structure.
In an omnidirectional WPT system, the energy can be transferred in any direction; however the receiving devices has its preferred field direction based on its positioning and orientation. To focus power transfer towards targeted loads, a smart detection algorithm for identifying the positioning and orientation of receiver devices based on the input power information is presented. The system efficiency is further improved by a maximum efficiency point tracking function. A novel power flow control with a load combination strategy to charge multiple loads simultaneously is explained. The charging speed of the omnidirectional WPT system is greatly improved with proposed power flow control.Doctor of Philosophy
Wireless power transfer (WPT) is a promising solution to deliver power to a battery in a variety of applications. Due to its convenience, wireless power transfer technology with loosely coupled coils has become popular in consumer electronics. In such system, the receiving coil embedded in the receiving device picks up magnetic field induced by the transmitter coil; therefore, energy is transferred through the magnetic field and contactless charging is achieved. Thus far, the majority of the coupled coils in these systems are planar structure, and the magnetic field induced by the transmitter coil is in one direction, meaning that the energy power transfer capability degrades greatly when there is some angle misalignment between the coupled coils. To improve the charging flexibility, a three–dimensional (3D) coils structure is proposed to transfer energy in different directions, also known as in omnidirectional manner. With omnidirectional magnetic field, the charging platform can provide energy transfer in any direction; therefore, the angle alignment between the transmitter coil and receiver coil is no longer needed. In a WPT system with loosely coupled coils, the energy transfer capability suffers from weak coupling condition. To improve the power transfer capability, the electrical resonance concept between the inductor and capacitor at the power transfer frequency is adopted. A novel compensation network is proposed to form a resonant tank with the loosely coupled coils and maximize the power transfer at the operating frequency. As for the WPT system with loosely coupled coils, the energy transfer capability is also proportional to the operating frequency. Therefore, Megahertz (MHz) WPT systems are used to improve the charging spatial freedom. 6.78 MHz is selected as the system operation in AirFuel standard, a wireless charging standard for commercial electronics. The zero voltage switching (ZVS) operation of the switching devices is essential in reducing the switching loss and the switching related electromagnetic interference (EMI) issue in a MHz system; therefore, a comprehensive evaluation of ZVS condition in an omnidirectional WPT system is performed. The big hurdle of the WPT technology is the safety concern related to human exposure of electromagnetic fields (EMF). Therefore, a double layer shield structure is first applied in a three dimensional charging setup to confine the electromagnetic fields effectively. The stray field level in our charging platform is well below the safety level required by the regulation agent. Although the energy can be transferred in an omnidirectional manner in the proposed charging platform, the energy should be directed to the target loads to avoid unnecessary energy waste. Therefore, a smart detection method is proposed to detect the receiver coil's orientation and focus the energy transfer to certain direction preferred by the receiver in the setup. The energy beaming strategy greatly improves the charging speed of the charging setup.
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O'Brien, Kathleen [Verfasser]. "Inductively Coupled Radio Frequency Power Transmission System for Wireless Systems and Devices / Kathleen O'Brien." Aachen : Shaker, 2007. http://d-nb.info/1166516717/34.
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Fan, Philex Ming-Yan. "Power management and power conditioning integrated circuits for near-field wireless power transfer." Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/290143.
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Near-field wireless power transfer (WPT) technology facilitates the energy autonomy of heterogeneous systems, significantly augmenting complementary metal-oxide-semiconductor field-effect-transistor (CMOS) technology. In low-power wearable devices, existing power conditioning integrated circuits do not maximize the power factor (PF) for rectification and power conversion efficiency (PCE) due to multiple conversion. Additionally, there is no core power management for the entire power flow. The majority of the research focuses on active rectifiers, which reduce the turn-on voltage for rectification. Certain studies target the output voltage regulation via feedback to the transmitter or direct battery charging without power maximization. Firstly, this study investigates a high-power factor WPT front-end circuit that is namely the mono-periodic switching rectifier (MPSR) and implemented in a 0.18µm 1.8V/5V CMOS process. Integrated phase synchronizers are used to align the waveshape of a wirelessly-coupled sinusoidal voltage source in a receiving coil to the corresponding conducting current. Using this approach, the PF can be increased from roughly 0.6 to unity without requiring any wireless or wired feedback to the transmitter. The proposed MPSR can also provide AC-DC rectification, and step up and down the sinusoidal voltage source's peak amplitude using a pulse-width modulator. Measured voltage conversion ratios range between 0.73X and 2X, and the PF can be boosted up to unity. Secondly, the wireless power system-on-chip (WPower-SoC) is proposed and implemented in a 0.18µm 1.8V/3.3V CMOS process. The WPower-SoC integrating power management can provide rectification, output voltage regulation, and battery charging. Additionally, the implementation of feedforward envelope detection (FED) can reduce the variation in a wireless power link and improve load transient responses. Simulated results demonstrate that 5% of the output voltage regulation is improved when an output load changes. Moreover, the FED reduces approximately 40% of the transient response time. Overshoot and undershoot voltages are decreased by 23% and 26.5%, respectively. The measured output voltage regulates at 3.42V and can supply output power up to 342mW. A temperature sensor as part of the power management core remains active when the WPT receivers enter sleep mode to prolong the battery usage time. In the final part of this study, a nano-watt high-accuracy temperature sensing core is implemented in a 0.18µm 1.8V/3.3V CMOS process that can self-compensate the temperature shift without the need for additional compensating techniques that consume extra power.
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Lantz, Fredrik, and Pontus Johansson. "Using Harvested Energy to Power a Wireless System and Measure Vibrations." Thesis, Linköpings universitet, Elektroniska Kretsar och System, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-131954.
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The work described in this paper aims to test whether or not it is possible to power a system on energy harvested from vibrations and use that energy to measure how much it vibrates. The goal has been to produce a prototype system that uses that technique to discover damages on drones in an early stage. The reader will get to experience everything from design to testing of the system. The reader will also get an insight in which problems occurred during the project, how they have been handled and which conclusions have been made.The system could be applied in a variety of different situations to detect damages and which could prevent the damages from leading to severe problems.Arbetet som beskrivs i denna rapport ämnar testa huruvida det är möjligt att driva ett system med alstrad energi från vibrationer och använda den energi för att mäta hur mycket det vibrerar. Målet har varit att ta fram ett prototypsystem som använder sig av tekniken för att upptäcka skador på drönare i ett tidigt stadie. Läsaren får uppleva allt från design av system till aktiva tester och får en inblick i vilka problem som uppstått under arbetet, hur de har bearbetats och vilka slutsatser som dragits.Systemet skulle kunna appliceras i många olika situationer för att upptäcka skador och skulle kunna förhindra att skadorna leder till allvarligare problem.
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WANG, YINGYING. "Power Transmitter and Battery Management IC for a Wireless Recharging System." Case Western Reserve University School of Graduate Studies / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1258845144.
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Le, Trong Nhan. "Global power management system for self-powered autonomous wireless sensor node." Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S048/document.
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La quantité d'énergie disponible dans les batteries et le nombre limité de cycles de recharge compliquent singulièrement la conception de réseaux de capteurs sans fil (WSN) autonomes. La récupération d'énergie dans l'environnement direct des nœuds et un stockage d'énergie à base de supercondensateurs sont aujourd'hui considérés comme solutions potentielles pour atteindre une durée de vie du réseau théoriquement infinie. Un gestionnaire d'énergie (PM pour ''Power Manager'') est embarqué dans chaque nœud afin de permettre un fonctionnement en neutralité énergétique (ENO), ce qui veut dire que les énergies récupérées et consommées par un nœud sont équivalentes sur le long terme. Dans cette thèse, nous proposons de nouveaux PMs qui adaptent dynamiquement l'intervalle de réveil des nœuds en fonction de l'énergie récupérée. La faible complexité de nos PMs, leur indépendance vis-à-vis du type de source d'énergie récupérée et leur faible empreinte mémoire facilitent leur implantation sur une plate-forme réelle de réseaux de capteurs sans fil. Par ailleurs, lorsque l'on considère un réseau multi-sauts, une variation trop fréquente de l'intervalle de réveil peut s'avérer pénalisante pour l'établissement de rendez-vous entre les nœuds et risque de fortement dégrader la qualité de services globale. Nous proposons donc un gestionnaire d'énergie (WVR-PM) qui limite autant que possible ces variations et qui permet d'améliorer le débit de près de 60% par rapport aux PMs de l'état de l'art tout en diminuant de 45% l'énergie consommée par une communication réussieThe limited energy and recharge cycles of batteries are crippling the design of autonomous Wireless Sensor Networks (WSNs). To overcome this issue, everlasting harvested energy and supercapacitor-based energy storage are considered as potential solutions to achieve a theoretically infinite lifetime. A Power Manager (PM) is embedded in each WSN node to respect the Energy Neutral Operation condition (ENO), which means harvested energy is equal to consumed energy for a long period. In this thesis, a set of PMs are proposed for energy harvesting WSN nodes to adapt their average consumed energy by changing the wake-up interval according to the available harvested energy. Our PMs are low complexity, independent of energy sources, small memory footprint and therefore, can be easily implemented on a real EH-WSN node. Another issue addressed in this thesis when considering a multi-hop EH-WSN is the effect of wake-up interval variations to the global QoS. Due to its low harvested energy, a relay node is impractical to synchronize with a transmitter if its wake-up interval regularly changes, therefore degrading the global QoS. A new power manager, named Wake-up Variation Reduction power manager (WVR-PM) is proposed to reduce the variations of the wake-up interval. By using WVR-PM, the throughput of a multi-hop EH-WSN can be improved up to 59% compare to state-of-the-art PMs while the average consumed energy for one successful communication is reduced by 45%
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Low, Zhen Ning. "High efficiency loosely coupled wireless power transfer system via magnetic induction." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0024707.
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Wang, Yingying. "Power Transmitter and Battery Management IC for a Wireless Recharging System." Cleveland, Ohio : Case Western Reserve University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1258845144.
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Thesis(M.S.)--Case Western Reserve University, 2009Title from PDF (viewed on 2010-01-28) Department of Electrical Engineering and Computer Science -- Electrical Engineering Includes abstract Includes bibliographical references and appendices Available online via the OhioLINK ETD Center
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Carvalho, Carlos Manuel Ferreira. "CMOS indoor light energy harvesting system for wireless sensing applications." Doctoral thesis, Faculdade de Ciências e Tecnologia, 2014. http://hdl.handle.net/10362/13127.
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Dissertação para obtenção do Grau de Doutor em
Engenharia Electrotécnica e de ComputadoresThis research thesis presents a micro-power light energy harvesting system for indoor environments. Light energy is collected by amorphous silicon photovoltaic (a-Si:H PV) cells, processed by a switched-capacitor (SC) voltage doubler circuit with maximum power point tracking (MPPT), and finally stored in a large capacitor. The MPPT Fractional Open Circuit Voltage (VOC) technique is implemented by an asynchronous state machine (ASM) that creates and, dynamically, adjusts the clock frequency of the step-up SC circuit, matching the input impedance of the SC circuit to the maximum power point (MPP) condition of the PV cells. The ASM has a separate local power supply to make it robust against load variations. In order to reduce the area occupied by the SC circuit, while maintaining an acceptable efficiency value, the SC circuit uses MOSFET capacitors with a charge reusing scheme for the bottom plate parasitic capacitors. The circuit occupies an area of 0.31 mm2 in a 130 nm CMOS technology. The system was designed in order to work under realistic indoor light intensities. Experimental results show that the proposed system, using PV cells with an area of 14 cm2, is capable of starting-up from a 0 V condition, with an irradiance of only 0.32 W/m2. After starting-up, the system requires an irradiance of only 0.18 W/m2 (18 mW/cm2) to remain in operation. The ASM circuit can operate correctly using a local power supply voltage of 453 mV, dissipating only 0.085 mW. These values are, to the best of the authors’ knowledge, the lowest reported in the literature. The maximum efficiency of the SC converter is 70.3% for an input power of 48 mW, which is comparable with reported values from circuits operating at similar power levels.
Portuguese Foundation for Science and Technology (FCT/MCTES), under project PEst-OE/EEI/UI0066/2011, and to the CTS multiannual funding, through the PIDDAC Program funds. I am also very grateful for the grant SFRH/PROTEC/67683/2010, financially supported by the IPL – Instituto Politécnico de Lisboa.
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Srivastava, Amit. "Design of Ultra Low Power Transmitter for Wireless medical Application." Thesis, Linköping University, Electronic Devices, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-18408.
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Significant advanced development in the field of communication has led many designers and healthcare professionals to look towards wireless communication for the treatment of dreadful diseases. Implant medical device offers many benefits, but design of implantable device at very low power combines with high data rate is still a challenge. However, this device does not rely on external source of power. So, it is important to conserve every joule of energy to maximize the lifetime of a device. Choice of modulation technique, frequency band and data rate can be analyzed to maximize battery life.
In this thesis work, system level design of FSK and QPSK transmitter is presented. The proposed transmitter is based on direct conversion to RF architecture, which is known for low power application. Both the transmitters are designed and compared in terms of their performance and efficiency. The simulation results show the BER and constellation plots for both FSK and QPSK transmitter.
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Hakemibarabadi, Amir. "Robust control of a wireless power transfer system for ventricular assist devices." Thesis, Queensland University of Technology, 2022. https://eprints.qut.edu.au/229219/1/Amir_Hakemibarabadi_Thesis.pdf.
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In recent times, wireless power transfer systems (WPTS) have been identified as a reliable option to supply power to heart pumps. When WPTS are used for heart pumps, they increase the number of required power converter stages and correspondingly hardware complexity. In addition, the existence of uncertainties in WPTS based medical implants such as load, and mutual inductance variations can lead to system instability or poor performance. To make a reliable closed-loop operation, a μ-synthesis robust controller is investigated for the medical implants to obtain a satisfactory performance which is critical for medical applications.
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Wu, Yun. "Null power reallocation for data rate improvement in a wireless multicarrier system." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/46539.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2008.Includes bibliographical references (leaves 65-66).
Multicarrier systems are advantageous for high data rate transmissions in wireless environments due to their ease of implementation and tolerance for multipath delay spread. Currently, these systems as specified by the IEEE 802.11 standards do not adapt to frequency-selective fading but simply choose a constant data modulation scheme and transmit power level for all sub carriers in the available signal bandwidth. Although these implementations maintain acceptable performance when channel conditions are poor, they do not efficiently utilize the full capacity of a transmission channel. In the prototype system of the Wireless Gigabit Local Area Network (WiGLAN) project at MIT, a more efficient scheme is demonstrated where the modulation scheme of each subcarrier is selected individually based on the Signal-to-Noise ratio (SNR). To further improve the data rate of the WiGLAN system, this thesis describes the design of an adaptive transmit power allocation scheme that involves redistributing the power of "null" sub carriers with extremely low SNRs to the sub carriers that are utilized for data transmission. Experimental results demonstrate functionality of the simple redistribution scheme using the prototype transceiver nodes over various wireless channels, and show an average data rate improvement of 4.38% when the redistribution power is provided by 8 null sub carriers. Furthermore, a higher complexity waterfilling redistribution scheme is simulated and compared against the simple redistribution scheme. The simulations of the waterfilling scheme predict a higher data rate increase of 13.2% over no redistribution if given the same power availability of 8 null subcarriers.
by Yun Wu.
M.Eng.
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Xia, YuXin M. B. A. Sloan School of Management. "Self-powered wireless sensor system using MEMS piezoelectric micro power generator (PMPG)." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/37091.
Full textAbstract:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references (leaves 99-102).
A thin-film lead zirconate titanate, Pb(Zr,Ti)03, MEMS Piezoelectric Micro Power Generator (PMPG) has been integrated with a commercial wireless sensor node (Telos), to demonstrate a self-powered RF temperature sensor module. PMPG and a power management module are designed to satisfy sensor node's power requirement. An electro-mechanical model of PMPG has been developed to maximize power output. The 2nd generation PMPG is designed to provide 0.173 mW power at 3 V DC with a natural frequency of 155.5 Hz. The power management module is developed to provide AC-DC rectification, energy storage, and active switching between PMPG and application circuit. To minimize power consumption, sensor data is taken at a discontinuous interval. A test bed is developed, which mimics that of a liquid gas pipeline used in the Alaska, where the self-powered sensor be used to monitor pipeline temperature.
by YuXin Xia.
M.Eng.
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Liu, Yu-Siang, and 劉宇祥. "Wireless Transcutaneous Power Conversion System." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/40139939432414108042.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
95
This thesis focuses on the wireless transcutaneous power conversion system and its goal is to develop a converter which converts DC input voltage to sinusoidal output voltage with constant frequency. First, different topologies of power converters are considered and the ringing choke converter (RCC) is chosen according to the required specifications of the targeting system. After that, a power conversion system is proposed based on the operation of RCC to provide sinusoidal output voltage with fixed frequency. The oscillation principles of the energy-storage circuit and the control mechanism of the feedback signals are discussed in the thesis. The oscillation frequency is determined by natural resonance between the capacitance in the energy-storage circuit and the leakage inductance on the primary side of the transformer. At the same time, the feedback signals are utilized to control the switch devices such that the oscillation can be sustained and the sinusoidal output voltage can be obtained on the secondary side of the transformer. Furthermore, if the area of the converter is preferred to be decreased for integration, a ring oscillator is presented to generate a square wave output with fixed frequency. By connecting the ring oscillator to a capacitor and a transformer, it can also transmit energy into the human body using sinusoidal wave and can be applied to the wireless transcutaneous power conversion system.
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CHANG, CHIA-WEI, and 張佳偉. "2.4GHz Wireless Power Monitor System." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/92910639135469637810.
Full textAbstract:
碩士中華大學
電機工程學系碩士班
99
With the maturing of wireless technology, and the integration of Wireless Sensor Networks (WSN) into daily life, a user can quickly be more familiar with the environments of their office buildings and homes through the use of WSN. The WSN can be useful to determine environment costs or electricity use and can be utilized by people to become more aware of their surroundings and deal with any problems that arise. Through the WSN, we can control remote power devices. By technology can be used to improve a person’s quality of life. This thesis aims to improve the combination of 2.4 GHz embedded systems, wireless transitions, and Ethernet Modules such heterogeneous network's performance, the rate of communication, and long-distance control in order to be managed effectively.
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CHANG, TING-WEI, and 張庭維. "Capacitive Wireless Power Transmission System." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/deqyz9.
Full textAbstract:
碩士國立臺北科技大學
光電工程系
107
Today's mainstream charging methods are directly transmitting power to our equipment through wired means, so the most intuitive way, the energy loss is also the most stable. However, because the length of the wire greatly limits the convenience of our charging. Therefore, to improve such a disadvantage, wireless power transmission is born. In this paper, we mainly study capacitive power wireless transmission. In view of the fact that wireless power transmission in the past is transmitted by inductive coupling, the way of inductive coupling is very large for the position, distance and wire of the coil. The impact of the study of capacitive wireless power transmission can improve the shortcomings of inductive wireless power transmission. The paper is divided into three major blocks. The first block is analog and impedance-matched, and the high-frequency system simulation software (HFSS) is used to simulate the S-parameter in the 50MHz~1 segment of 1MHz, and then the impedance is matched to make the power transfer from one end to the other. Achieve the best efficiency. The second block is to make an experimental model and compare the difference between capacitive and inductive. In the third block, the corresponding circuits at the front and rear ends, such as the signal end and the rectifying end, are fabricated.
33
Xue, Xin-Tai, and 薛心太. "Wireless Power Conversion Chip and System." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/2v22x9.
Full textAbstract:
碩士國立臺北科技大學
電腦與通訊研究所
102
With the global alternative energy issues, electric cars began to walk on general road surface, the thesis used in the wireless charging technology for electric vehicle charging, the initial use of the object lock for the elderly scooter. In this thesis, establishment of the wireless charging system, the primary power transfer stage transfers power in wireless by Inductive Coupling Class E Power Amplifier. In order to optimize efficiency of wireless charging system and obtain enough charging distance, the inductive coupling class E power amplifier will be optimized efficiency first. Two coupling distance specific of the inductive coupling class E power amplifier are 7cm and 14 cm to be designed. The coupling coils are more than 23cm in diameter. Efficiency of the two coupling distance specific of the inductive coupling class E power amplifier were improved to more than 83%, and output power is more than 20W by realized class E power amplifier principle, impedance matching, coupling coil analysis and design. Second, bridge rectifier was joined in the secondary side. The efficiency was optimized after joining bridge rectifier. Finally, the system joins DC-DC buck converter, charger and lead acid battery to become a wireless charging system to achieve wireless charging function. Finally, in this thesis, it contains a high voltage DC-DC buck converter chip design, the design motivation is reducing the impact ratio of voltage drop relative to input voltage to improve system efficiency, the architecture of the DC-DC buck converter chip is voltage-mode control, the high voltage DC-DC buck converter are fabricated by TSMC 0.25 um CMOS technology.
34
LUO, GUO-CHENG, and 羅國宸. "Smart Matrix Wireless Power Transfer System." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/ae7qaa.
Full text
35
Wu, Sheng Fu, and 巫勝富. "Wireless Remote Power Saving Control System." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/55938616059942119623.
Full textAbstract:
碩士國立臺北大學
資通科技產業碩士專班
102
This thesis adapts ZigBee, a wireless sensor network technology, and combines a power monitoring chip and power control switch to present an integrated remote power saving control solution. Based on this approach, devices can perform power saving and safety monitoring as an intelligent building for companies and families. Based on ZigBee capabilities of low power, low cost, high performance, self-healing, and interference resistance, our implementation is developed upon Texas Instrument MSP430 AFE253 (AC meter IC) and CC2531(ZigBee IC), which are linked by UART interfaces. Through realistic accuracy testing and adjustments, the experiments simulate efficient ZigBee wireless transmissions for evaluating the wireless power monitoring system, which includes multiple wireless devices. By the integration of hardware and software as well as wireless technology adaption, This paper successfully accomplish the wireless remote power saving control system.TTT
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Che-Wei, Chang, and 張哲維. "Embedded Wireless Power Quality Data Transmission System." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/44474506361282112240.
Full textAbstract:
碩士國立彰化師範大學
電機工程學系
103
Recently, a rapid development of the high-tech industry results in a wide use of high-tech production equipment. This high-tech production equipment is different from normal appliances which is stricter in the requirement of power quality. The suspension of production from the instability of power supply frequently causes the conflict between users and power companies. In order to solve the problem of the power quality, the analysis of power data needs to be firstly conducted. For this purpose, we need a complete system to continuously monitor the time, the amplitude, and the frequency of the instability of power quality in the semiconductor industry supply equipment. Therefore, the responsibility between users and power companies can be clarified when the problem happens. This study is intended to monitor the power quality. Firstly, the waveform in need of surveillance was measured using sensing circuit. Secondly, the waveform was input into embedded systems and conducted a Haar wavelet transform. The transformed wavelet coefficients were compressed using Huffman compression algorithm and the compressed data were further wirelessly transmitted to the server with ZigBee. Finally, the data was decompressed in the server and transformed into the original waveform using an inverse wavelet transform interface. This system performed on the development platform of Altera cyclone FPGA used Quartus II and NIOS II as an experimental platform. This study performed comparison between decompressed and inverse wavelet transformed data using Matlab. Moreover, the root mean squared error between decompressed and inverse wavelet transformed data was also estimated. The results indicate the back-transformed data through wavelet transform, data compression and wireless transmitting can reconstruct the original power signal.
37
Wu, Wu-wei, and 吳武偉. "Transmit Signals on Wireless power Transfer System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/91793873212769148728.
Full textAbstract:
碩士國立中央大學
通訊工程學系在職專班
101
The wireless power transfer technique is potential, due to a more convenience and getting attention. The purpose of this work is to add the signal transmission functions over the wireless power transfer. In the architecture of the wireless power transfer, both the transmitter and receiver side individually have an LC resonant circuit, which has been adjusted with the same LC resonant frequency. On the transmitter side a half-bridge circuit is used for driving coil to generate an alternating magnetic flux. In this design, the maximum efficiency of wireless transmission is about 53.34%, and the maximum output power is about 2.22W. With an input 1 KHz wireless square wave, over a carrier with frequency of about 109 KHz. To transfer the signal to the receiver, then the receiver can demodulate the 1 KHz signal. From the measurement results it demonstrated that the signal transmission over the wireless power transfer system is feasible.
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Lian, Fang-Yi, and 連芳儀. "Wireless power transmission system between stacked dies." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/27503718262247461419.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
101
A wireless power transmission system for stacked dies in 3D-IC is implemented by using coupled inductors. There are three common methods for wirelessly power transfer: inductive coupling, capacitive coupling and antenna radiation. We hope the wireless power transmission system can offer more than mW power. Unfortunately, only inductive coupling can provide over mW power transmission. Besides, inductive coupling interconnect has longer transmission distance as compared with capacitive interconnect. This is why we choose inductive coupling. In this thesis, we propose an impedance matching method to improve the efficiency of inductive transmission, including how to select a better matching point for the rectifier. A sine-wave signal generator is adopted as a source for power transmission. On the other side, there is a receiving inductor and a rectifier at the receiver. The proposed receiver of wireless power transmission system is implemented in TSMC 0.18μm CMOS process and the transmitter of wireless power transmission system is implemented in GIPD process respectively for demonstration of this architecture. The simulated received power and efficiency for transmitting inductor including rectifier are 4.7mW and 34.89% respectively.
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Ji, Jun-An, and 紀俊安. "Wireless power transmission system between stacked dies." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/12423365969816367280.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
99
A wireless power transmission for stacked dies in 3D-IC is implemented by using coupled inductor design. There are three common methods for wirelessly power transfer: inductive coupling, capacitive coupling and antenna radiation. We hope the wireless power transmission system can offer more than mW power. Unfortunately, only inductive coupling can provide over mW power transmission. Besides, inductive coupling interconnect has longer transmission distance as compared with capacitive interconnect and antenna. This is why we choose inductive coupling. In this thesis, we implement two systems in different transmission distances. The transmission distance is 15μm and 70μm respectively. A sine-wave signal generator is adopted as a source for power transmission. On the other side, there is a receiving inductor and a rectifier at the receiver. The proposed receiver of wireless power transmission system is implemented in TSMC 0.18μm CMOS process and the transmitter of wireless power transmission system is implemented in Al2O3 process and GIPD process respectively for demonstration of this architecture. The simulated received power and efficiency for transmitting inductor using Al2O3 process are 38.10mW and 25.93% respectively. The measured received power and efficiency for transmitting inductor using GIPD process are 3.28mW and 10.36% respectively.
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Sethy, Kiranbala. "Development of an Efficient Wireless Power Transfer System." Thesis, 2018. http://ethesis.nitrkl.ac.in/9668/1/2018_MT_216EE4308_KBSethy_Development.pdf.
Full textAbstract:
Accessing of power is a crucial necessity for any electrical/electronic circuit. Power can be transferred by physically i.e wires, cables etc or non-physically i.e wireless. Power transmissionfrom the source to load without any connecting wire or cable is called Wireless Power Transmission. Wireless power transfer is the rising pattern in the world today. The concept of power transfer without conducting wire was realized by Nikola Tesla. By using this concept transferring power can eliminates the use conventional copper cables and current carrying conductor. Different techniques are there for transfer power wirelessly for near field and far field also. This wireless power transmission technique is useful where conducting wires are inconvenient, or impossible. With wireless power transfer the important parameter is the efficiency. In this project presents the concept of transmitting power without using wires i.e. inductive coupling by which the transmission and distribution losses can be reduced. To improve the efficiency of wireless power, different types of receiver circuit also used. We also discussed the different types, block diagram, efficiency of Wireless Power Transmission (WPT).
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Tai, Ming-Chun, and 戴明淳. "Wireless Power Transfer System for 2.4 GHz Band." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/7aq584.
Full textAbstract:
碩士國立高雄應用科技大學
光電與通訊工程研究所
101
This thesis discusses the design of wireless power transfer system at 2.4 GHz band. It focus on the component designs, coupled dipole antenna and rectifier filter circuit, fed in for WLAN band.The antenna gain is enhanced by using the array antenna. Two types of antenna were studied in this thesis, planar and 3-D antenna. One protrusion is placed on the ground plane, which increases the phase lag of the current of one antenna to match the current phase of the sister antenna. Hence, the antenna gain of the array antenna is significantly improved. The array-antenna is fed into the rectifier filter. The rectifier filter circuit converted the RF signal into DC output. The wireless power transfer system described above was finally examined and shown a great performance.
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Chen, Chih-Yu, and 陳智裕. "Device-under-charge in Wireless Power Transfer System." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/s8ep54.
Full text
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Lu, Yi-hsing, and 呂昱興. "Wireless Signal Power Level-Based Indoor Positioning System." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/13081327442864083005.
Full textAbstract:
碩士國立中央大學
通訊工程學系在職專班
103
In the development of Indoor Positioning System, a wide range of technology is universal available. Any wireless related technology which can achieve positioning can be adapted. With Wi-Fi solution becomes ubiquitous it is a vital technology to support, in our day-to-day life. In fact, we are covered by many Wi-Fi signals wherever we are. Along with it being a built-in feature on modern smartphones, therefore Wi-Fi technology is the most commonly obtainable wireless technology. This thesis proposes to use the Power Level (PL) in Wi-Fi Access Point (AP) to support indoor positioning. The APs periodically sends beacons with unique Service Set Identifier (SSID), which carries the coordinates and corresponding PL value. AP broadcasts beacons using different power levels, one at a time. Smartphone can easily collects the visible APs with certain power levels and then find out the 2 intersections of any pair of nearest APs. Using the coordinates of visible APs, we can filter out the available 4 intersections within viewable range. Using these filtered intersection points, we can find out the center point of the polygon, which is the estimated position of the smartphone. Simulation results reveal the derived error of positioning is tolerable.
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Yi-FangYu and 游宜芳. "Array Patch Antenna for Wireless Power Transfer System." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/25224378536048659204.
Full textAbstract:
碩士國立成功大學
微電子工程研究所
104
Wireless Power Transmission (WPT) is a hot issue for energy transmits method nowadays. In WPT system, distance, gain and efficiency transmission are the key factors between transmitter and receiver. In this paper we focus on the Microwave Radiation method and would use a patch antenna array for our experiment. Some of the advantages of patch antenna array are high gain, high directivity. By combining several antennas in an array configuration, the performance would increase tremendously comparing to a single element. The result of this experiment shows that the antenna's characteristic of gain increased from 0.49 to 8.7 dBi, and the radiation efficiency increased from 20.4 % to 87.2 %. When the distance of each array patch antenna is 1 cm, the energy receive is measured as 182 µW. However, when antenna’s transmission distance is far from the other, the power which the antenna received will decrease. Compared to a single element array, the array antenna has higher gain of energy and further transmission distance. Thus it can receive more power and the efficiency can be highly promoted.
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SHAKYA, ABHISHEK. "IMPLEMENTATIONOF WIRELESS POWER SYSTEM FOR ELCTRIC VEHICLE APPLICATIONS." Thesis, 2022. http://dspace.dtu.ac.in:8080/jspui/handle/repository/19328.
Full textAbstract:
The goal of this study is to see if an inductive-coupled Wireless Power Transfer
(WPT) System can be used for electric vehicle charging in MVDC power networks.
WPT in electric vehicles (EVs) can provide a more convenient charging option than
static charging in a station, which can take hours. It can also reduce the risk of
electrocution from the use of physical media such as wires in EV charging. Despite the
fact that inductive coupling has been used in some WPT applications, it is still inefficient
for transferring high power at the kilowatt level due to weak coupling between the
transmitter and receiver. Using correctly configured resonant circuits in conjunction
with inductive coupling can improve coupling and make the system more efficient.
The goal of this study is to construct and evaluate a 2-KW WPT circuit. A
resonant circuit's optimal specification is investigated and described. The component
values in the circuit are determined using theoretical calculations. The WPT system is
validated in a MATLAB/SIMULINK environment.
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Chen, Yan-Ru, and 陳彥儒. "Design and Implementation of Power Oscillator forResonance-based Wireless Power Transfer System." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/z2ha52.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
107
Due to the development of portable, medical and industrial devices, the usage of mobile devices is getting higher and higher. To charge safely, the technology of wireless power transfer is needed. The common wireless charging methods for mobile devices are inductive coupling and resonant coupling. The inductive coupling uses the mutual inductance generated by the magnetic field when the two coils are close. The disadvantages of inductive coupling are the short coil distance and additional loss caused by reactive power. The resonant coupling is to compensate the two coils to the same resonant frequency with capacitors. Eliminating the imaginary impedance to create a load close to pure resistance, and a good transmission distance can be achieved. The resonant coupling alliances include Qi and AirFuel Alliance, and the AirFuel Alliance uses the 6.78 MHz ISM band. The advantage is that the distance and coil placement have lower impact on transmission efficiency. The wireless power transfer system implemented in the thesis is divided into three parts. The first part is the analysis of two coupling coils, including series-series coupling and series-parallel coupling. The second part is to use the Class E power amplifier to drive the coil of the wireless power transfer system, deriving the formula and design parameter for Class E power amplifier, and using series-parallel coupling to transmit power. According to measurement, the output power of the Class E power amplifier is about 1.89 W and efficiency is up to 83.66 %. The coil transmission efficiency is 80.52 %. The overall system efficiency is 67.36 %. The third part is to reduce the complexity of transmitter, eliminating the need for additional signal generator and driving circuits. The Class E power amplifier is made into a power oscillator by LC feedback, and using series-parallel coupling to transmit power. According to measurement, the output power of the power oscillator is about 2.22 W and efficiency is up to 73.38 % when the coil distance is 0.5 cm. The coil transmission efficiency is 92.84 %. The overall system efficiency is 68.13 %.
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Chen, Bo-Cian, and 陳柏芊. "A Wireless Power Transmission System Based on Solar Power and Switched Beam for Charging Multiple Wireless Sensor Nodes." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/67325508083126265184.
Full textAbstract:
碩士國立臺灣大學
電信工程學研究所
104
In the thesis, we propose a new far-field wireless power transmission system at 2.45 GHz ISM band, including a power source and energy harvesting circuits for wireless sensor nodes. To the best of our knowledge, no publish work has discussed the design that contains both RF power transmitter and receivers for WSNs in a solar based wireless power transmission system. By observing the regulations of Federal Communication Committee (FCC), we have implemented the system and suggested several parameter settings and selections of hardware for design. Moreover, in most RF harvesting scenarios, RF sources are not steady but solar power density is relatively high, so we make a combination of solar power and RF harvesting in our proposed system. Solar power is collected and then transformed into controllable RF power for transmission in four desired directions. As for wireless sensor nodes, the RF harvesting circuit is designed and implemented with about 20~30% RF-DC conversion efficiency, and a new charging logic is proposed as well. In summary, a whole-system scope of WPT technique is illustrated and can be a good example of the rechargeable WSNs design in the future.
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Liu, Jui-His, and 劉瑞璽. "Chip and system integration design of wireless power transmission." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/ctbe77.
Full textAbstract:
碩士國立雲林科技大學
電子工程系
102
This paper presents a maximum power tracking system for wireless power transmission based on the resonant inductor and capacitor coupling. Transmitter coupling of the system adopted a mixing of series-parallel coupler to promote transmission distance. Receiver used parallel resonant to reduce the output impedance. By frequency scanning, the maximum power point can be tracked to find resonant frequency during only about 3 seconds. Receiver can detect the maximum sensing power and feedback to transmitter, where the sensing voltage becomes high as closer to the resonant frequency, finally stops at the maximum power point. This method substantially improves the efficiency of wireless transmission, to avoided mismatching between the inductor and capacitor. For battery charging system, the use of constant current charging mode can significantly reduce the charging time to improve wireless charge efficiency. Discharge time is shorted by 50% compared the commercially charger. For the Li battery of 3.7V 3000mAh, the charging time is reduced to 250 minutes, while the commercially charger charging time is about 400 minutes. The wireless charged with maximum power tracking system had been prototyping in success. We design four chips for the proposed wireless charge system using TSMC 0.25um CMOS HIGH VOLTAGE MIXED SIGNAL. One is a full-bridge power driver that transmits energy transferred to charger by the air. The second is the maximum power tracking chip that can automatically find the optimal resonant frequency by scanning. The third chip is for battery charger that designed a constant current charging and time controller. The last one is for voltage sensing circuit and high frequency transmission in receiver. The voltage at the maximum power transferred point can be detected and noticed the transmitter. Aspects of the chip size, the transmitter chip contains maximum power point tracking and full-bridge driver IC chip occupied 1.2 × 1.2mm2 and 0.9 × 1.15mm2 , respectively. Receiver chip includes charger and data transfer system, which employed the chip area of 0.9 × 1.15mm2 and 0.9 × 1.2mm2.
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Tsai, Tsung-Min, and 蔡宗旻. "Study on Wireless Smart Energy-Saving Power Outlet System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/30605164164978806872.
Full textAbstract:
碩士龍華科技大學
電機工程系碩士班
101
In recent years, with the advance and automatic technology, people are more concern about the home environment. Thus, people need the smart home more increasingly. Nowadays, the world is facing energy shortage problem, however, energy saving issue is constantly discussed. In order to make life wisdom, increasing the convenience of life, also combined with the energy savings. For these reasons, we developed a Wireless Smart Energy-Saving Power Outlet System. Due to people now go to work for a long time, causing many inefficient home appliances waste. Nay appliance required power to operate, in this paper "outlet" is the main point to discuss. Wireless Smart Energy-Saving Power Outlet System is made up by smart phone and single chip, use this system by wireless can decrease the problem of communication. It divided into Wi-Fi and Bluetooth. Wi-Fi remotes home appliances with remote server, and it can be the desktop or notebook for remote control. Bluetooth transmission is the use of smart phone that combine mobile applications and control for normal, time and state control. In this paper, we successfully design a smart energy saving outlet that using wireless transaction model to do much functional control. Not only saving efficiency and accomplish life convenience but also no damaging the home decoration.
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Tsai, Jia-Shiun, and 蔡佳勳. "Development of Wireless Power Transfer System for Electric Scooters." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/24824021917727779435.
Full textAbstract:
碩士國立臺南大學
綠色能源科技學系碩士班
102
The goal of this paper is to design a wireless power transfer system for electric scooters which was based on the magnetic resonant coupling theory. Using a lower cost way to produce the circuit, the electric scooter may bring more convenient to the user and the system is suitable for any 48v/20Ah electric scooter. In this research, the system’s operation frequency can be satisfied to the standard of 85kHz which is required by SAE J2954, making the wireless power transfer system a safety standard and bring us a pleasant charging process. One circular antenna/receiver pair is designed to meet the requirements of scooter-using scenarios. The emitting coil were setup under the chassis of scooter, and the receiving coils were embedded in the bottom layer of the chassis where the air gap between two coils is larger than 10cm. We also designed a 3D directional antenna which is improved from general antennas. Leading the magnetic field emission lines directly to the receiving coil effectively, and enhance the charging efficiency and safety of the wireless charging system on the electric scooters。