科技英语英译汉.docx

1、科技英语英译汉 科技英语翻译（电子类）电磁波类论文翻译姓 名： XXXXX 学 号： 130810XXXX 学 院： 理学院 专 业： 电子信息科学与技术 任课教师： XXXXXXX 1.2.1 Wireless Power Transmission MechanismsWPT is the transmission of electrical energy from a power source to one or more loads without directly using solid wires or conductors. It can be generally classifi

2、ed as radiative or non-radiative based on the energy transmission mechanisms. In the radiative or far-field technology, also called power beaming, power is transferred in the form of electromagnetic radiation like microwaves or laser beams 5-9. Relying on the high-frequency signal emission of a powe

3、r source, energy can be transported over long distances, which would be much greater than the size of the transmitting and receiving devices like the antenna. Due to the omni-directional propagation of electromagnetic waves in the air, the transmitter must be aimed at the receiver to increase the en

4、ergy transmission efficiency. In addition, the potential health risks of human exposure to electric, magnetic, and electromagnetic fields in the open environment are associated with all wireless power systems from short range to long-range, low power to high power, low frequency (kHz) to high freque

5、ncy (GHz), which limit the non-radiated technology as well 10-14. The non-radiative or near-field technology can transfer power within short range compared to its radiative counterpart. It further falls into two further categories, capacitive coupling and inductive coupling. In the capacitive coupli

6、ng technology 15-20, power is transmitted through the electric field between a pair of metal plates, which form a capacitor. Due to the limitations of the hazardous voltages imposed on the electrodes required to transfer a certain amount of power, it shows advantages only in low-power small-air-gap

7、(within 1 mm) applications, though thepotentials in kilowatt-level applications have recently been reported in 19-20. In contrast, the inductive coupling technology 21-22 makes use of the magnetic field induced by the alternating currents in a pair of coils, like a transformer, which is suitable for

8、 low to high power levels over a longer energy transmission distance (1 mm). Due to the fact that the magnetic coupling between two adjacent coils in an inductively-coupled WPT system is usually weak, its power transfer efficiency will drop tremendously as the air-gap becomes longer. In order to inc

9、rease the efficiency of an inductively-coupled WPT, the magnetic resonance technology is used, where power is transferred by the magnetic field between two resonant circuits, one in the transmitter coil and the other in the receiver coil. For example, one capacitor is connected in series with the tr

10、ansmitter and another capacitor is connected in parallel with the receiver, which are used to compensate the leakage inductance along each power flow loop so as to tune the two circuits at the same desired resonant frequency. It has been reported in 23-24 that using magnetic resonance can effectivel

11、y increase the transmission range while maintaining an acceptable efficiency. Thereby this technology contributes to the rapid development of WPT fromshort-range to mid-range 25-30 and is adopted by most inductive WPT systems nowadays. The discussion in the following chapters will focus on the induc

12、tively-coupled WPT employing magnetic resonance. 1.2.2 ApplicationsWPT is regarded as a preferable solution for contactless supply of power over a certain air-gap. Due to its exclusive advantages of safety, flexibility, and convenience, it finds various applications ranging from microwatt biomedical

13、 implantable devices to kilowatt battery charging systems. A. Biomedical implants. Biomedical implantable devices, such as glucose monitoring implants, pacemakers, and cochlear implants as shown in Figure 1.3, are widely used to monitor diseases, stimulate human organs, and deliver medicines. Howeve

14、r the risks of the battery-replacing surgery when the energy stored is depleted has become an issue. What is more, the bulky battery embedded in the electronic devices limits the miniaturization of the implants, which has crucial significance for effectiveness and patient safety. The technology of w

15、ireless powering, or transcutaneous energy transmission, enables convenient wireless charging, and even removal of the battery. The use of WPT through radio-frequency electromagnetic waves in biomedical applications has kindled since the 1970s 31-34. Nowadays it has been successfully implemented in

16、artificial hearts 35-37, cardiac pacemakers 38-40, cochlear implants 41-42, and other genericbiomedical implantable devices 43-45. Several control methods have been reported in 46-50 to fulfill the output regulation purpose while maintaining high efficiency against the coupling and loading changes.

17、B. Consumer electronics. One big application field of WPT lies in consumer electronic products, among which the most successful commercialization case is the wireless battery charging technology for mobile phones 51-57. The planar winding topology with a charging surface is regarded as the most suit

18、able for the low power mobile and wearable device charging as well as many other consumer electronic devices of higher power levels. Despite the features of safety and convenience compared with the cord-based charging methods, the adoption of a common wireless charging platform for a range of consum

19、er electronics has environmental significance in that it can reduce the dumping of tons of wasted chargers. Figure 1.4 lists some wireless charging products available on the market. C. Electric vehicles. The development of the electric vehicle (EV) technology is regarded as an effective way to reduc

20、e the great demand for fossil fuel demand and greenhouse emissions. Despite the environmental benefits, EVs have not got the business success in the market due to the bottleneck of the battery technology. The insufficient energy density, low lifetime, and high cost of Lithium-ion batteries 58-59 whi

21、ch are currently used in most EVs greatly constrain the overall performance of an EV and can make it unattractive to consumers. For example, the energy density of the commercialized Lithium-ion batteries in EVs is only 90100 Wh/kg, which is so poor compared with the gasolines 12000 Wh/kg. In additio

22、n, the plug-in charger has disadvantages like increased risks in hostileenvironments, and reduced reliability under harsh climates, in particular in cold snowy zones. Therefore it is essential to find a convenient, safe, and reliable solution to charge EVs. Inductive-coupled WPT is regarded as a pre

23、ferred alternative 60-65. WPT can get rid of the charging cables and connectors and contactlessly charge an EV when it is parked over an effective charging area, using so-called stationary charging 66-74. The transmitter on the ground and the receiver on the vehicle should be accurately aligned to e

24、nsure continuous power flow at high efficiency in spite of the loose coupling between the transmitting pad and the receiving pad. Several new structures of the charging pads have been proposed in 69-71, 73-74 to enhance the magnetic coupling and achieve good tolerance to misalignment. Investigations

25、 on optimal compensation design and control methods have been reported in 66-68, 72 to build an efficient wireless charging system. Figure 1.5 depicts a prototypical stationary wireless charging system where the blue circle on the ground is the transmitting pad. Dynamic wireless charging, which make

26、s use of electrified roadways, can provide continuous power transfer when the EV is moving, and thereby reduce the on-board battery capacity 75-84. This online charging technology can make EVs more competitive over traditional internal combustion vehicles and more popular in the market. The design c

27、oncerning different kinds of power supply rails along the roadbed and associated pickup coils on the chassis of the cars has been widely investigated. Figure 1.6 demonstrates the concept of a dynamic wireless charging system where multiple lumped coils aligned on the road constitute the charging tra

28、ck and can provide power supply when the EV is passing over them one by one. It is believed that the overall battery capacity of EVs will grow considerably when they get widely used in the near future. At that time the wireless EV charging system will play an important role in smart grid management

29、85-87. The bidirectional WPT technology 88-93 can make every single EV which is indirectly connected to the grid take part in power flow management in the grid like load balancing by valley filling. D. Other miscellaneous applications. Besides the aforementioned, WPT can be widely used in otherappli

30、cations. It finds applications in factory automation, for example decentralized power supply in a manufacturing floor 94, and contactless energy transmission for servo motors 95. An innovative company has been founded to provide wireless lighting solutions 96. WPT is an efficient way to achieve unde

31、rwater power delivery 97-98 and can be adopted in underground mining 99-100. More potential applications in challenging environments are to be exploited. 1.2.3 System Design ConsiderationsThere are several important factors to consider while designing a WPT system. From the previous discussion, the

32、concept of magnetic resonance requires a capacitor connected with the coil to compensate its self-inductance, or leakage inductance. In Figure 1.7 four basic compensation topologies are presented depending on how the compensate capacitors are connected with the coils, which are series-series (SS), series-parallel (SP), parallel-series (PS), and parallel-parallel (PP), where L1 is the self-inductance of the transmitter, R1 is the coil resistance of the transmitter, L2 is the self-inductance of the receiver, R2 is the coil resistance of the re