CONCEPTS, QUALITY FACTOR AND EFFICIENCY OF "WIRELESS POWER TRANSFER"
Abstract
The present text provides information regarding introductory concept of wireless power transfer through some of the existing technologies and evaluate its quality factor as well as deals with certain methods of improving the efficiency of wireless power transfer. Its figure of merit, transfer loss, quality factor and efficiency been calculated and analysed.
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Introduction
Since its inception by Nicolas Tesla in 1905, the idea of transfer of electrical power by using no wires has been a continuous effort worth doing for scientists and researchers. Many of them actually have succeeded for small distance transfer through coupling methods and some of them are trying to send electrical power to very large distance using methods involving electromagnetic radiations and LASERs. Here we will discuss some mid to high range power transfer techniques through performance enhancement and improved efficiency for radiative and non-radiative modes using resonance as the key factor to improve efficiency as well as power output.
Conclusion
Aristeidis Karalis, J.D. Joannopoulos, and Marin Soljačić4 In comparison of the two classes of resonant systems under examination4, the strong immunity to extraneous objects and the absence of risks for humans probably makes the conducting-wire loops the preferred choice for many real-world applications; on the other hand, systems of disks (or spheres) of high (effective) refractive index have the advantage that they are also applicable to much smaller length-scales (for example in the optical regime dielectrics prevail, since conductive materials are highly lossy).
In conclusion, we present a scheme based on “strongly-coupled” resonances for mid-range wireless non-radiative energy transfer. Although our consideration has been for a static geometry (namely κ and Γe were independent of time), all the results can be applied directly for the dynamic geometries of mobile objects, since the energy-transfer time (1κ−μ−∼1100s for microwave applications) is much shorter than any timescale associated with motions of macroscopic objects. Analyses of very simple implementation geometries provide encouraging performance characteristics and further improvement is expected with serious design optimization. Thus the proposed mechanism is promising for many modern applications. For example, in the macroscopic world, this scheme could potentially be used to deliver power to robots and/or computers in a factory room, or electric buses on a highway (source-cavity would in this case be a “pipe” running above the highway). In the microscopic world, where much smaller wavelengths would be used and smaller powers are needed, one could use it to implement optical inter-connects for CMOS electronics, or to transfer energy to autonomous nano-objects (e.g. MEMS or nano-robots) without worrying much about the relative alignment between the sources and the devices.
As a venue of future scientific research, enhanced performance should be pursued for electromagnetic systems either by exploring different materials, such as plasmonic or metallo-dielectric structures of large effective refractive index, or by finetuning the system design, for example by exploiting the earlier mentioned interference effects between the radiation fields of the coupled objects. Furthermore, the range of applicability could be extended to acoustic systems, where the source and device are connected via a common condensed-matter object.