毕业翻译无线输能技术基于磁共振的中距离无线能量中继传输

1、原文midrange wireless energy transfer systemwith relay via magnetic resonancedai xuguang yu kai chen qian tan chong zhou zhigang bu zhiyong（shanghai institute of microsystem and information technology of chineseacademy of science shanghai 200050 china）abstract wireless energy transfer by coupled magne

2、tic resonances is a popular technologywhich energy can be transferred via coupled magnetic resonances in the non-radiative near-field. thispaper proposes a four coils magnetic resonance system with relay. based on circuit analysis and simulation, we designed and optimized circuit parameter of the sy

3、stem to make the system worked at magnetic resonance. experimental results show that with relay the end-end efficiency is 33.4%, whilethe end-end efficiency is just 22.1% without relay. with relay the end-end efficiency can increase 11.3% comparing with the efficiency without relay; the maximum tran

4、sfer distance can increase about twice of coil diameter comparing with the distance without relay. experimental results indicate that relay can increase the end-end system efficiency and the transfer distance of a magnetic resonance system.keywords: wireless energy transfer, magnetic resonance, ener

5、gy relay, efficiency1 introductionwith the rapid development of mobile devicessuch as mobile phone and tablet computer, there has been an increasing interest in wireless power-transfer technology. specially, significant progress has been madefor inductively coupled systems 1-3 . also inductively cou

6、pled power-transfer systems have been widely used, including vehicle battery-charging systems, and very high end-to-end system efficiency of up to 80% has been documented 1 , however, most studies have been restricted to close range(i.e., typically shorter than 30% of the coil diameter.) the transmi

7、ssion distance is generally close to 1cm 1 and 15cm is considered a fairly large distance 3 . results at midrange (i.e., more than twice the coil diameter) rarely been reported. one of the technologies to achieve midrange distance of a wireless energy-transfer system is mag- netic resonances. the ma

8、gnetic resonances techno- logy was first proposed by massachusetts institute of technology 2007, thus presenting a potential break-through for midrange wireless energy transfer. the mits scheme was carried with a power transfer of 60w, end-to-end system efficiency of 15%, and rf-to-rf coupling effic

9、iency of 40% for a distance of 2m, which is more than three times the coil diameter 4 . since then, there have been few reports on practical design of magnetic resonance system 5, 6 and some pure physical theory analysis on magnetic resonance technology 7, 8 . however, in many previous papers the en

10、d-to-end system efficiency is still lower than 30%and there are few research on a four coils magnetic resonance system structure with relay and how relay influence the system efficiency and transfer distance. in this paper we design a high end-to-end efficiency wireless energy-transfer system via ma

11、g- netic resonance with relay and analyse how relay influences the transmission distance and end-to-endefficiency of a magnetic resonance system.2 analysis of magnetic resonance systemwith relaythe basic principle of magnetic resonance technology is that two separate coils with same resonance freque

12、ncy are possible to form a resonantsystem based on high frequency magnetic coupling and exchange energy in a high efficiency, while the coupling effect is weak between those objects with different resonance frequency. there are also many research works on two coupled magnetic resonance coils ， but f

13、ew reports on four coils magnetic resonance system with relay. a system consisting of four coils can be interpreted as an expansion of a transformer, which consists of two coils.fig.1 schematic of four coupled magnetic resonance coils with relayas shown in fig.1, the system is composed off our coils

14、: power, sending, relay, and load coils. in this system, all four coils are coupled with each other. the cross couplings are very weak, and they will be neglected in the following analysis. if we neglect the cross-coupling terms(k pr , k s l , k pl ), we can make the equivalent circuit shown in fig.

15、2.fig.2 simplified circuit of four coupled magnetic resonance coils with relawe assume a lossless case for simplicity. basedthe theory of circuit ,we can calculate the mutual impedance z rm induced at the relay coil by the load coil isthe mutual impedance z sm induced at the sending coil by the rela

16、y coil and load coil isthe mutual impedance z pm induced at the power coil by the sending, relaying, load coil isbased on the magnetic resonance technology, we know the resonance frequency of the sending coil equals the frequency of relaying coil, we havethe impedance term of the capacitor andinduct

17、or is zero at the resonance frequency.thus, eq. (1)eq. (5), z pm is reduced toif l p is the same as l l and the resonance frequency, of the power coil is also the same as that of the sending coil, we havethus eq. (6)、eq. (7), z pm is reduced toif we are able to setthen c p is negligible, and z in is

18、 perfectly matched to z 0 . theoretically, the coupling efficiency becomes 100%. although k s r is small due to the long transfer distance, we can make k p s /kr l /k s r into unity by adjusting the spacing between the power coil and sending coil or between the relaying and load coils. as a result,

19、we can achieve high coupling efficiency and we will test and verify this result in our experiment.3 experimental researchaccording to the structure proposed, the experi-mental device has been made, shown in fig.3. fig.3 experimental devices of magnetic resonance coils with relay and without relayin

20、our system, we improved the efficiency of driving circuit by design the mos tube worded at zero voltage switch state, then power wasted by driving circuit can be greatly decreased .the systems resonance frequency is 3.579mhz and can be stabilized with a crystal oscillator, the power is a dc 12v/36w

21、power, the diameter of the four coil is 150 mm with line diameter 1.6mm. the curl turns are 1, 2, 4, 4, corresponding to powering curl, sending curl ,relaying curl to load curl.we test the maximum transfer power parameters and the results are shown in tabwhen with relay, the current and voltage of t

22、he sending coil are 920ma and 12v, and we can get the rf-rf =62.3%. from the table we know the relay can increase the end-end system efficiency and transfer distance, also the power of load.further more, we analyze the relationship between transfer distance and end-end system efficiency, also the re

23、lationship between transfer distance and power of load. as shown in fig.4.（a） under the situations with relay and without relay, relationship between end-end efficiency and transfer distance（b）under the situations with relay and without relay ,relationshipbetween power of load and transfer distancef

24、rom the left curves in fig.4, we can see basically the end-end efficiency with relay is higher than end-end efficiency without relay，except when the distance is about 20cm where the strong magnetic resonance occurs of the system without relay. also with the same efficiency, the transfer distance wit

25、h relay is longer than the transfer distance without relay. for example, when end-end efficiency is 0.3, thetransfer distance with relay is 48cm meanwhile the transfer distance without relay is just 28cm, the relaycan increase transfer distance up to 20cm.from the right curves in fig.4, we can see t

26、he power of load with relay is higher than the power of load without relay from 27cm to 70cm, the reason why the power of load with relay is lower than the power of load without relay from 0cm to 27cm is that from 0cm to 27cm the system with relay did not work at magnetic resonance. secondly from th

27、e curves we can see that when with relay the maximum power of load is about 6.8w and the distance is about 40cm; but without relay the maximum power of load is about 1.3w and the distance is about 20cm.further morewith relay the maximum transfer distance can extended to 60cm, meanwhile the maximum t

28、ransfer distance without relay can only reach 30cm.4 conclusion、based on the experimental result and analysis of magnetic resonance system with relay, it is proved relay can increase the end-end system efficiency and the power of load. also with the same power, relay can extend the effective transfe

29、r distance. next we will do some research work on multiple relay of magnetic resonance system and make the system more practical.reference1 low z n, chinga r a, tseng r, et al, design and test of a high-power high-efficiency loosely coupled planar wireless power transfer systemj. ieee trans. ind. el

30、ectron., may 2009, 56(5): 1801-1812.2 casanova j j, low z n, lin j. a loosely coupled planar wireless power system for multiple receiverj. ieee trans. ind. electron., 2009, 56(8): 3060-3068.3 sallan j, villa j l, liombart a, et al optimal design of icpt systems applied to electric vehicle battery ch

31、arge j. ieee trans. ind. electron., 2009, 56(6): 3060-3068.4 kurs a, karalis a, moffatt r, et al. wireless power transfer via strongly coupled magnetic resonancesj. science, 2007, 317(5834): 83-86.5 zhu c, liu k, yu c, et al. simulation and experimental analysis on wireless energy transfer based on

32、magnetic resonancesc. vehicle powerpropulsion conf., harbin, china, 2008: 1-4.6 chen c j, chu t h, lin c l, et al. a study of loosely coupled coils for wireless power transferj. ieee trans. circuits syst. ii, exp. briefs, 2010, 57(7): 536-540.7 karalis a, joannopoulos j d, soljacic m. efficient wire

33、less non-radiative mid-range energy transferc. ann. phys., 2008, 323(1): 34-48.8 harris s e. electromagnetically induced transpa-rencyj. phys. today, 1997, 50(7): 36-42.译文基于磁共振的中距离无线能量中继传输戴旭光 俞 凯 陈 谦 谭 冲 周志刚 卜智勇（中国科学院上海微系统与信息技术研究所 上海 200050）摘要:磁耦合谐振无线能量传输的是一个受欢迎的技术能量可以被转移通过无辐射近场耦合的磁谐振。这提出了一种四个继电器线圈磁

34、共振系统。基于电路分析和模拟,我们设计和优化电路参数的系统,使系统工作核磁共振。实验结果表明,与继电器的底端效率是33.4%,没有继电器底端效率仅为22.1%。继电器的底端效率可以提高11.3%与效率没有继电器;的最大传输距离可以增加两倍没有继电器线圈直径与距离。实验结果表明,继电器增加底端系统效率和磁共振系统的传输距离。关键词:无线能量传输、磁共振、能量传递,效率1介绍移动设备的快速发展手机和平板电脑等,无线功率转换是越来越感兴趣技术。特别,已取得显著进展电感耦合系统1 - 3。还归纳耦合功率转换系统已经广泛使用,包括车辆蓄电池充电系统,非常高的端到端系统效率高达80%已经记录了1,然而,大

35、多数研究被局限于近距离(即。,通常是短超过30%的线圈直径)。传输距离通常是接近1厘米1和15厘米3认为是一个相当大的距离。结果在中端(即。线圈直径的两倍多)很少报道。达到中档的技术之一距离无线能量传送系统的杂志共振。磁场共振电子-呆呆的被麻省理工学院首次提出2007年技术, 因此提出一个潜在的突破对于中档无线能量转移。麻省理工学院的方案用60 w,端到端系统效率15%,rf-to-rf耦合效率为40%的距离2米,这是三倍以上的线圈直径的4。从那时起,很少有报告实用磁共振系统的设计(5、6)和一些纯物理理论分析磁共振技术(7、8)。然而,在许多先前的论文端到端系统效率仍低于30%很少有研究在四

36、个线圈磁共振系统结构与继电器和继电器影响系统效率和传输距离。在本文中,我们设计一个高的端到端效率通过杂志无线能量传送系统磁共振传递和分析如何传递影响传输距离和端到端磁共振系统的效率。端到端系统效率仍低于30%很少有研究在四个线圈磁共振系统结构与继电器和继电器影响系统效率和传输距离。2磁共振系统与继电器的分析核磁共振的基本原理技术是两个不同的线圈相同共振频率是可能形成基于高频磁耦合和交换能量效率高,这些对象之间的耦合效应较弱不同的谐振频率。也有很多研究工作在两个耦合的磁共振四线圈磁线圈,但很少报道共振系统传递。组成的一个系统四个线圈可以被解读为一个扩张的由两个线圈的变压器。图1 四个耦合磁共振的示意图与继电器线圈如图1所示,系统组成四个线圈:力量、发送、传递和负载线圈。在这个系统,所有四个线圈是相互耦合的。交叉耦合很弱,他们会忽视了以下分析。如果我们忽视了交叉耦合条件(k公关,k s l, k pl),我们可以图2所示的等效电路。图2 简化电路四个磁耦合共振与继电器线圈为了简单起见,我们假设无损的情况下。基于电路理论,我们可以计算出相互的在继电器线圈的阻