Resonant inductive coupling wireless power transfer. Magnetic resonant coupling as a potential means for. One of the latest proposals, termed resonant wireless power transfer, enables the efficient cordless transmission of electric power to a stationary device 3,4. It is reliable, efficient, fast, low maintenance cost, and it can be used for short range or long range. These resonant qi transmitters are compatible with all qi phones out there today. Design and analysis of a wireless power transmission. Nair, sidharth bhakth abstractan investigation into the feasibility of wireless power transmission through inductive. Figure 2 wireless power transmission circuit with resonant coupled coils. Use matlab to determine the inductive and capacitive values for designing a tunedresonant inductive wireless power transfer triwpt system. The magnetically coupled resonant wireless power transfer mcrwpt system for implantable medical devices has gradually become one of the research hotspots.
Due to its openloop architecture, rbc faces the challenge of providing dynamic current and voltage to optimize battery charging performance. Naturally, then, resonant inductive coupling shows great promise in maximizing the efficiency of wireless power transfer. The mathematical model of the systems transmission characteristics is established by equivalent circuit theory. Due to the behavior of ric systems, this wpt method is very suitable for broadcast applications where coils could be. Wireless power transmission using magnetic resonance. During the course of this research, we investigated the need and usefulness of wireless power transmission and the feasibility of using magnetic inductive. Resonant wireless charging design needs more than simply an understanding of the. In a wireless power transmission system, a transmitter device, driven by electric power from a power source, generates a timevarying electromagnetic field, which transmits power across space. This chapter provides a general overview of magnetic resonant wireless power transfer systems based on network models. The goal of the project was to develop a wireless power transfer wpt system and implement it in innovative flooring. Designing a qicompliant receiver coil for wireless power systems, part 1 overview the implementation of the wireless power consortiums wpcs qi standard1 brings wireless power to many different end applications.
Based on this, main circuit design and analysis of the transmission system is given. The project was researched by former cornell students lucas jorgensen and adam culberson in the year 2008 2. With everincreasing concerns for the safety and convenience of the power supply, there is a fast growing interest in wireless power transfer wpt for industrial devices, consumer electronics, and electric vehicles evs. The power transferred to a receiver load at resonance is derived and explained. Safe, efficient, and over distance introduction driving home from the airport, marin noticed his new smart phone was low on battery once again. Equations of the efficiency and frequency are derived for basic. Wireless power transfer circuit working, advantages and. Equivalent circuit and calculation of its parameters of magneticcoupledresonant wireless power transfer 3 ds d dd hs hd ra rb rs rd x y z port1 port2 fig. Inductive versus resonant wireless charging digikey. The design of robust wpt systems is challenging due to its positiondependent power transfer efficiency pte. Pdf design and analysis of resonant wireless power transfer. Wpt is useful to power electrical devices where are inconvenient, or not possible, as is the case of body embedded sensors, actuators. Figure 2 shows a schematic representation of an inductive coupling approach to impedance matching. Classe power amplifier design for wireless power transfer air fuel resonant wireless charging overview tight coupling is defined as a coupling factor k greater than 0.
According the circuit theory, reactive power is present in a system with imperfect compensation. Maximizing efficiency of wireless power transfer with. Resonant wireless power transfer infineon technologies. If we put a resistor in the circuit above, the energy exchange in the absence of a power supply will be damped and finally stops. Architects of wireless power transfer systems face a couple of choices in the configurations of coils.
An inductive wireless power transfer wpt system consists of transmitter electronics, transmit coil, receive coil and receiver electronics. Positioninsensitive wireless power transfer based on. Equivalent circuit and calculation of its parameters of. Wireless power transfer wpt is the transmission of electrical power without wires and is based on technologies using timevarying electric, magnetic, or electromagnetic fields. Wireless energy transfer by resonant inductive coupling master of science thesis rikard vinge. The mit team demonstrated the highly resonant technique using a magnetic field to transfer energy over a midrange distance of 2 meters, and an industry was born. High power wireless power transfer for the industrial environment 2.
Magnetic resonance and magnetic induction what is the best choice for my application. In this paper, a new approach is presented to address wpts strong sensitivity to the. Pdf an overview of resonant circuits for wireless power. Circuit model for resonant cavity mode enabled wireless. Wireless power transfer wpt, wireless power transmission, wireless energy transmission wet, or electromagnetic power transfer is the transmission of electrical energy without wires as a physical link.
Capacitance errors of a wireless power transfer system with ss topology yi wang, fei lin, zhongping yang and zhiyuan liu. Adaptive resonant beam charging for intelligent wireless. Resonance and wireless power how wireless power works. Grajski, ryan tseng and chuck wheatley qualcomm incorporated san diego, ca, usa abstract looselycoupled lc wireless power transfer wpt offers unique, nextgeneration improvements in user experience, and product design and innovation towards the vision. In wireless charging the coupling is loose with k typically less than 0. Although the technology has existed for some time and some. An overview of resonant circuits for wireless power transfer. Wireless power transfer via strongly coupled magnetic. Imagine a future in which wireless power transfer is feasible. A general design of magnetic coupling resonant wireless power.
Wireless power transfer via strongly coupled magnetic resonances 1. Witricity corporation witricity highly resonant wireless power transfer is. The transmission characteristics of the system in weakcoupling regions are of research significance. Because a parallel lc circuit draws, ideally, no current at its resonant frequency, in theory all power drawn from the ac source will be emitted as em waves to be received by the secondary. The equivalent circuit of magnetic resonant couplingbased wireless power transfer wherel1, l2, c1, c2, r1and r2are the inductance, the capacitance, and resistance of the transmitter and the receiver coils, respectively, and rloadis the load resistance. Modulating wireless power signal to carry data bidirectionally.
As the resonant circuit is one of the cores of both the nearfield and farfield wpt systems, it is a pressing need for. Resonant wireless charging design needs more than simply an understanding of the properties of the. Resonant wireless charging is much more forgiving of the receiver placement as long as the receiver is placed somewhere on the resonant wireless charging pad, power transfer can be established. Wireless power transmission in wireless power transmission by resonance. Designing a qicompliant receiver coil for wireless power. Wireless power transfer an overview sciencedirect topics. Wireless energy transfer, resonant inductive coupling, induction, resonantcircuits,ferrite.
An 1803 pl16 1803 210431 class e power amplifier design. This oscillator offers multiple benefits it oscillates independently and only requires a dc source. As the resonant circuit is one of the cores of both the nearfield and farfield wpt systems, it is a pressing need for researchers to develop a highefficiency high. Summary the full solution of the wireless power transfer problem requires a systemslevel approach with dynamically linked parameters between the circuit and 3d fea model. The mathematical model of the wireless power transfer system through inductive coupling method is illustrated in this section. The basic working principle of wireless power transfer is, two objects having similar resonant. Abstractwireless power transfer via magnetic resonant coupling is experimentally demonstrated in a system with a large source coil and either one or two small receivers.
We study wireless energy transfer systems consisting of two resonant circuits that. Build and test lc resonator circuits based on matlab findings and tune them to specified frequencies. The project was done at nextfloor oy, a company based in helsinki, finland. Image courtesy of reference 3 resonant wireless charging will be a good choice once chips supporting the technology. A closelycoupled inductive wireless charging system such as one adhering to the qi specification exhibits higher power transfer efficiency than a resonant system such as one adhering to the rezence specification. The equivalent circuit of the link is shown in fig. In such a link, each coil is capacitively loaded forming a tuned lc resonating at a common frequency, which allows to transmit significant power over a wider ranges. Whats more, about the future research work is its functional operation accomplishment. Wireless power transfer using resonant inductive coupling. This is where the resonance comes in and helps the efficiency dramatically by. The ltc4120based resonant coupled system uses dynamic harmonization control dhc to. An inductive wireless power transfer wpt system consists of transmitter electronics. As the resonant circuit is one of the cores of both the near. Pdf design and analysis of resonant wireless power.
The mutual inductance between the two coils is given by. Nearfield resonant based wireless power transfer wpt technology has a significant impact in many applications ranging from charging of biomedical implants to electric vehicles evs. White paper benefits of gan emode hemts in wireless. Sensor networks one of the potential applications of ric systems is wpt networks. Wireless power can be defined as the transmission of electrical energy from a power source to an electrical load without connecting wires. As electricity travels through this coil, the coil begins to resonate. Wireless power transfer using resonant inductive coupling for 3d. Pdf in this paper, the modelling and analysis of resonant wireless power transfer rwpt system are carried out by using circuit theory.
Evs25 shenzhen, china, nov 59, 2010 wireless power. Magnetic resonant coupling based wireless power transfer. Resonant inductive coupling wireless power transfer author. Analysis of the influence of compensation capacitance. Magnetic resonant coupling based wireless power transfer system with inband communication sunhee kim, yongseok lim, and seungjun lee abstractthis paper presents a design of a wireless power transfer system based on magnetic resonant coupling technology with inband wireless communication. Abstractas a longrange highpower wireless power transfer wpt technology, resonant beam charging rbc can transmit wattlevel power over long distance for the devices in the internet of things iot. This paper introduces the basic structure and working principle of magnetic coupling resonant wireless power transmission. Recent advances in circuits wireless power transfer. Its hd display, and apps using gps, bluetooth, and lte4g data communications conspired to drain the battery quickly.
Wireless energy transfer by resonant inductive coupling. Benefits of gan emode hemts in wireless power transfer gan power devices in resonant class d and class e radio frequency power amplifiers abstract wireless charging for portable devices dispenses with the need for conventional adapterschargers with their associated cables and connectors. In section ii, we will discuss power transfer efficiency. Figure 1 a resonant wireless power transfer system consists of a driven lcresonator on the transmitter side and another lcresonator on the receiver side inductive wireless power transfer wpt is limited to just a couple of millimeters distance between the transmitter and the receiver. In this work a general circuit model for the cavity resonant wireless power system is introduced and validated against simulated and measured results. The optimal condition and numerical analysis on maximum power transfer efficiency will be introduced. Getting rid of cables for the ease of operators of medical devices. In 10, an lcc resonant network is proposed to adjust the current. Wireless power transmission by magnetic resonance circuits. Results show an average agreement between the circuit model and measured transfer ef. Resonance between source and load coils is achieved with lumped capacitors terminating the.
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