Fundamentals of inductively coupled wireless power. In this paper, parameter analysis of the inductive coils is evaluated for low power wireless power transfer wpt applications. A criterion proposed for inductive coupling and magnetic. Unveiling nonlinear dynamics in resonant inductively coupled. Circuitmodel based analysis of wireless energy transfer. Equivalent circuit and calculation of its parameters of. The purpose is to design the desired circuit in order to transfer power wirelessly. Inductive coupling and magnetic resonance coupling. Wireless power transfer via strongly coupled magnetic resonances andre kurs, 1 aristeidis karalis,2 robert moffatt, j. The effectiveness of the proposed condition has been examined both theoretically and experimentally. In section ii, we will discuss power transfer efficiency. The feasibility of efficient wireless power transfer wpt via coupled magnetic resonances has previously been demonstrated both experimentally 1,2,3 and theoretically 3,4,5.
Use matlab to determine the inductive and capacitive values for designing a tunedresonant inductive wireless power transfer triwpt system. Similar to inductive power transfer scheme, resonant. In this project, wireless power transfer relies on electromagnetic resonance. In this paper, current developments and research progress in the scmr area are presented. Resonant inductive coupling wireless power transfer author. This can be remedied by resonant inductive coupling. Resonant coils analysis for inductively coupled wireless power. Inductive power transfer technology a typical ipt system as shown in figure1 consists of two physically detached subsystems with power transfer through induction. Wireless energy transfer by resonant inductive coupling master of science thesis. During the course of this research, we investigated the need and usefulness of wireless power transmission and the feasibility of using magnetic inductive coupling.
Wireless power transfer through inductive coupling inase. Resonant inductive coupling or magnetic phase synchronous coupling is a phenomenon with inductive coupling where the coupling becomes stronger when the secondary loadbearing side of the loosely coupled coil resonates. Midrange power transfer implemented this way can be nearly omnidirectional. When the load coil is placed in the magnetic field of source coil, a voltage is induced in a load coil by inductive coupling and thereby power transfer occurs 2, 3. The circuit theory behind coupledmode magnetic resonance. Abstractthe wireless power transfer wpt efficiency of a mobile wearable medical device mwmd by strongly coupled magnetic resonance scmr method is studied here for airtissue interfaces. Pdf in this paper, parameter analysis of the inductive coils is evaluated for low power wireless power transfer wpt applications. Wireless power transfer via inductive coupling youtube. Resonant coupling analysis for a twocoil wireless power.
The coupleda criterion of inductive coupling and magnetic resonance coupling in wireless power transfer system is proposed. Resonant inductive coupling ric the transmission of wireless power transfer using electromagnetic induction was first demonstrated in the early 20th century by nikola tesla. Coupled magnetic resonance is considered to be a key enabling technology for midrange wireless power transfer. Andre kurs left, john joannopoulos and aristeidis karalis. In this paper we will introduce wireless power transfer using resonant inductive coupling for 3d ics to increase power transfer efficiency and density with smaller coils. An article published in the science magazine as wireless power transfer via strongly coupled magnetic resonances by andre kurs, science 317, 832007. The more loops the coil makes, the bigger the field will be. This setup was designed for a specific industrial application. 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.
Inductive wireless power transfer wpt is limited to just a couple of millimeters. Efficient and easytouse wireless charging is the next major step in freeing our devices from their wired connections. A general equivalent circuit model is developed for a wireless energy transfer system composed of multiple coils via coupled magnetic resonances. Selection of maximum power transfer region for resonant. Fskbased simultaneous wireless information and power. Based on the concept of tesla, the circuit was designed using two parallel inductors that are mutually coupled. Poynting vector analysis for wireless power transfer. Jun 07, 2007 wireless power transfer over twometer distance, from the coil on the left to the coil on the right, where it powers a 60w light bulb. A closely coupled 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 resonance of an inductively coupled system increases the amount of magnetic flux linked between coils and improves the power transmission significantly. Unveiling nonlinear dynamics in resonant inductively. Wireless power transfer via strongly coupled magnetic resonances. Kurs a1, karalis a, moffatt r, joannopoulos jd, fisher p, soljacic m. During the course of this research, we investigated the need and usefulness of wireless power transmission and the feasibility of using magnetic inductive.
In this condition, the alternating field amplitude in the primary inductor is constant, a 2 t a 2 e. Already back in 2007, fmtc demonstrated the technical feasibility of inductive wireless power transfer based on strongly coupled magnetic resonant circuits at 27 mhz 7. The core of the used technology is making use of the magnetic resonance concept for transmitting the power wirelessly for charging any mobile. Inductive versus resonant wireless charging digikey. Decomposition of the wireless power setup at top level already back in 2007, fmtc demonstrated the technical feasibility of inductive wireless power transfer based on strongly coupled magnetic resonant circuits at 27 mhz 7. The simulation of the project has been done using ni multisim 14. Based upon this control method two optimal control schemes are. This new technology can be used in various wireless power transfer applications with different specifications, necessities, and restrictions such as in electric vehicles and consumer electronics. Wireless power transfer wpt concept offers users the freedom from annoying wires, and allowing seamless powering and charging of portable devices in an unburdened mode. To verify the developed model, four types of wireless energy transfer systems are fabricated, measured, and compared with simulation results. General analysis of resonance coupled wireless power transfer. Using selfresonant coils in a strongly coupled regime, we experimentally demonstrated efficient nonradiative power transfer over distances up to 8 times the radius of the coils. The system is inductively coupled via coils and it also contains capacitors, which we use to tune the performance. Wireless power transfer through inductive coupling is proposed in this paper.
A karalis, jd joannopoulos, and m soljacic, efficient wireless nonradiative midrange energy transfer, annals of physics 323 2008. The optimal condition and numerical analysis on maximum power transfer efficiency will be introduced. Recent advances in circuits wireless power transfer. In order to uphold the maximum power transfer in a resonant inductively coupled wireless power transfer system, an operating region has been proposed based on the coupling coefficient, frequency and electric load. Image courtesy of reference 3 resonant wireless charging will be a good choice once chips supporting the technology. The resulting expressions illustrate the performance bounds of wireless power transfer using resonant magnetic coupling and are useful in the design of wireless power transfer systems. To model a system composed of ncoils, node equations are built in the form of an nbyn matrix, and the. Ab kurs et al, wireless power transfer via strongly coupled magnetic resonances, science 317 2007. Wireless power transfer using resonant inductive coupling for. A resonant transformer of this type is often used in analog circuitry as a bandpass filter.
This paper presents a resonant inductive link for power and data transfer to a pulse generator implanted in the chest. A literature survey on wireless power transfer for. Effect of the dclink capacitor size on the wireless. The effectiveness of the proposed condition has been examined both theoretically and. Fundamentals of inductively coupled wireless power transfer. Witricity type magnetic resonance coupling systems add another set of resonant coils on the primary power source side which pair with the coils on the secondary load bearing side. Equivalent circuit and calculation of its parameters of magnetic coupled resonant wireless power transfer 3 ds d dd hs hd ra rb rs rd x y z port1 port2 fig. Haus, waves and fields in optoelectronics, prentice hall publishers, englewood 3.
Resonant inductive coupling is also being used in wireless power systems for portable computers, phones, and vehicles. Wireless energy transfer through strongly coupled resonances. The mathematical model of the wireless power transfer system through inductive coupling method is illustrated in this section. Wireless power transfer can make a remarkable change in the field. Power transfer through strongly coupled resonances by andre kurs submitted to the department of physics on august 10, 2007, in partial fulfillment of the requirements for the degree of master of science in physics abstract using selfresonant coils in a strongly coupled regime, we experimentally demonstrate. Strongly coupled magnetic resonance scmr, proposed by researchers at mit in 2007, attracted the worlds attention by virtue of its midrange, nonradiative and highefficiency power transfer. Poynting vector analysis for wireless power transfer between. The objective of this chapter is to study the fundamentals and operating principles of inductively coupled wireless power transfer icwpt systems. Applications involving microwaves, solar cells, lasers, and resonance of electromagnetic waves have had the most recent success with wpt. Advantages of scmr are analyzed by comparing it with the other wireless power transfer wpt technologies, and. Wireless power transfer via strongly coupled magnetic resonances 1. We present a quantitative model describing the power transfer, which matches the experimental results to within 5%. Wireless inductive coupled power transfer and opportunity battery charging are very appealing techniques in drone applications.
Wireless energy transfer system with multiple coils via. Pdf analysis of wireless power transfer on the inductive. Wireless power transmission using resonance inductive. Wireless power transfer using resonant inductive coupling for 3d. This paper proposes wireless power transfer wpt system, consisting of transmitterreceiver coils along with some conditioning and stabilizing.
This corresponds to the function of a transformer with loose coupling. Inductive coupled wireless,power transfer, resonant frequency, experimental measurements. Among the numerous resonant wireless power transfer mechanisms, the one resonant power tranfer consortium announce using 6. Inductive link for power and data transfer to a medical. A detailed numerical analysis using cmt is beyond the scope of this project, but a brief overview is possible. The project was researched by former cornell students lucas jorgensen and adam culberson in the year 2008 2. This concept is an emerging technology, and in coming years the distance of power transfer can be enhanced as the research across the world is still going on. Safe, efficient, and over distance background the idea of transmitting power through the air has been around for over a century, with nikola teslas pioneering ideas and experiments perhaps being the most wellknown early attempts to do so 1. There is interest in wireless power transfer wpt for implantable and wearable biomedical devices, for example, heart pacemaker or implantable electrocardiogram ecg recorders. Calculation model ds d dd hs hd ra rb rs rd mm 50 300 50 200 200 250 250 300 300 table 1. Since then, electromagnetic induction emi has been used for the powering of artificial hearts and implantable devices. Wireless circuits based on resonant inductive coupled power transfer icpt are very appealing for application to. Transfer efficiency optimal control of magnetic resonance. Resonant inductive coupling as a potential means for wireless.
If one can operate in that regime in a given system, the energy transfer is expected to be very efficient. Fskbased simultaneous wireless information and power transfer in inductively coupled resonant circuits exploiting frequency splitting peter a. Pdf development of a wireless power transfer system. A network comprised of interconnected sensor nodes exchanging sensed data by wired or wireless communication. Figure 2 wireless power transmission circuit with resonant coupled coils. 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. Members of the team that performed the experiment are obstructing the direct line of sight between the coils. The theory values are obtained by using the theoretical.
Witricity or wireless electricity resonance inductor. The main function of wireless power transfer is to allow electrical devices to be. Wireless power transfer via strongly coupled magnetic. Wireless power transmission using magnetic resonance. A literature survey on wireless power transfer for biomedical. Specifically, scmrs wireless power transfer from a source of air to a sensor close to tissue is analyzed. Wireless power transfer using resonant inductive coupling. Any time electrical current moves through a wire, it creates a circular magnetic field around the wire. Wireless power transmission using resonance inductive coupling. Weight and size are very critical constraints in drones, so the battery and the onboard electronics must be as light and small as possible. Inductive coupling how wireless power works howstuffworks. There are two methods that are widely used in wireless power transfer system. Build and test lc resonator circuits based on matlab findings and tune them to specified frequencies. The analytical model of a wireless power transfer scheme can be developed through coupled mode theory cmt.
Resonant wireless power transfer infineon technologies. Pdf general analysis of resonance coupled wireless power. Inductive coils are the major element used in the wpt systems, in which different shaped coils are employed. Ipt system can effectively transmit power from a source to a device using the principle of em induction, just like the operation of a transformer, and is also nonradiative as the system does not rely on the propagation of. The proposed link consists of two planar resonators and has been optimized for operating in the medradio band centered at 403 mhz. First, circuit models are studied to gain knowledge on how the circuit component parameters in. Tunedresonant inductive wireless power transfer triwpt. This paper concentrates on the applications based on nearfield power transfer methods.
Nonetheless, the closedform cmt formulation presented in the literature was limited to 2coils. Power transfer through strongly coupled resonances by andr6 kurs submitted to the department of physics. The technologies, listed in the table below, differ in the distance over which they can transfer power efficiently, whether the transmitter must be aimed directed at the receiver, and in the type of electromagnetic energy they use. In the late 20th century, the nearfield inductive power transfer ipt,,, became concerned when the cordless charging of portable consumer devices gained popularity. The basic icpt circuit consists of two magnetically coupled resonant circuits, i. This setup was designed for a specific industrial application involving a translation movement of the receiver coil and, although very different from our new application. Hoeher, fellow, ieee abstractinductively coupled resonant circuits are affected by the socalled frequency splitting phenomenon at short distances. Since then, electromagnetic induction emi has been used for the powering of. A computational study on the magnetic resonance coupling. Bending the wire into a coil amplifies the magnetic field.
Wireless energy transfer by resonant inductive coupling. Models and systems have hitherto considered linear resonators as underlying dynamics. While data transfer of mobile devices is already wireless, charging is typically still performed with cables. This thesis addresses three important parts of resonant inductive energy transfer. Resonant wireless power transfer abstract our mobile devices are becoming more and more wireless. There are many ways to transfer power wirelessly, but standard method is electromagnetic induction. These results are validated with the experimental setup shown in figure 1. The technology for wireless power transmission or wireless power transfer wpt is in the forefront of electronic development. Using optimallyspecified resonant circuits along with inductive coupling can enhance the coupling and make the system more efficient for practical applications. In contrast to the more conventional inductive power transfer scheme, our approach here is closely associated with a resonant power transfer scheme.
Cmtbased analysis took circuit designers by surprise when the group physicists at mit demonstrated a method of achieving high pte by utilizing multiple coils 3 and 4coils for wireless power transmission. Strongly coupled magnetic resonance scmr, proposed by. A design of inductive coupling wireless power transfer system for. Resonant inductive coupling is also being used in wireless power systems for. Wireless power transfer to mobile wearable device via. Andrea carloni, federico baronti, roberto di rienzo. The resonance of an inductively coupled system increases the amount of magnetic flux linked between coils and improves the power transmission significantly 5. The onboard components involved in the resonant inductive coupled wireless power transfer usually consist of the. In steady state analysis, which applies to the conventional inductive power transmission links, f s t in is a sinusoidal signal described as a s e. Wireless power transfer over twometer distance, from the coil on the left to the coil on the right, where it powers a 60w light bulb. However, these two terms have been ambiguously used without clear definitions. In order to suppress the fast decrease of the transfer efficiency of magnetic resonance coupled wireless power transfer system mrcwpts with distance increase, this paper investigates the impact factors of the system transfer efficiency and is, then formulates a new efficiency optimal control method based on frequency control.
1509 88 714 1094 571 501 84 1304 1186 403 293 827 30 1311 1251 1512 1523 212 756 156 1479 40 1276 549 483 1541 297 698 886 1186 1265 1494 956 1327 768 1354 334 377 527 1036