https://www.mit.edu/~soljacic/wireless-power_AoP.pdf

Efficient wireless non-radiative mid-range energy transfer

Starting from Tesla's principles of wireless power transfer a century ago, this critical review outlines recent magneto-inductive research activities on wireless power transfer with the transmission distance greater than the transmitter coil dimension. It summarizes the operating principles of a range of wireless power research into 1) the maximum power transfer and 2) the maximum energy efficiency principles. The differences and the implications of these two approaches are explained in terms of their energy efficiency and transmission distance capabilities. The differences between the system energy efficiency and the transmission efficiency are also highlighted. The review covers the two-coil systems, the four-coil systems, the systems with relay resonators and the wireless domino-resonator systems. Related issues including human exposure issues and reduction of winding resistance are also addressed. The review suggests that the use of the maximum energy efficiency principle in the two-coil systems is suitable for short-range rather than mid-range applications, the use of the maximum power transfer principle in the four-coil systems is good for maximizing the transmission distance, but is under a restricted system energy efficiency (<;50%); the use of the maximum energy efficiency principle in relay or domino systems may offer a good compromise for good system energy efficiency and transmission distance on the condition that relay resonators can be placed between the power source and the load.

A Critical Review of Recent Progress in Mid-Range Wireless Power Transfer

Inductive power transfer (IPT) has progressed to be a power distribution system offering significant benefits in modern automation systems and particularly so in stringent environments. Here, the same technology may be used in very dirty environments and in a clean room manufacture. This paper reviews the development of simple factory automation (FA) IPT systems for both today's complex applications and onward to a much more challenging application-IPT roadway. The underpinning of all IPT technology is two strongly coupled coils operating at resonance to transfer power efficiently. Over time the air-gap, efficiency, coupling factor, and power transfer capability have significantly improved. New magnetic concepts are introduced to allow misalignment, enabling IPT systems to migrate from overhead monorails to the floor. However, the demands of IPT roadway bring about significant challenges. Here, compared with the best FA practice, air-gaps need to be 100 times larger, power levels greater than ten times, system losses ten times lower to meet efficiency requirements, and systems from different manufacturers must be interoperable over the full range of operation. This paper describes how roadway challenges are being met and outlines the problems that still exist and the solutions designers are finding to them.

Modern Trends in Inductive Power Transfer for Transportation Applications

Disclosed is an apparatus for use in wireless energy transfer, which includes a first resonator structure configured to transfer energy non-radiatively with a second resonator structure over a distance greater than a characteristic size of the second resonator structure. The non-radiative energy transfer is mediated by a coupling of a resonant field evanescent tail of the first resonator structure and a resonant field evanescent tail of the second resonator structure.

Wireless energy transfer

1. Introduction 2. Creation under consumption 3. Innovation under competition 4. The evil of intellectual monopoly 5. The devil in Disney 6. How competition works 7. Defenses of intellectual monopoly 8. Does intellectual monopoly increase innovation? 9. The pharmaceutical industry 10. The bad, the good, and the ugly.

/pdf/against-intellectual-monopoly-40tcgfb66f.pdf

Against Intellectual Monopoly

Apparatus for transmitting electrical energy.

Art of transmitting electrical energy through the natural mediums.

Apparatus for transmission of electrical energy.

THE theoretical possibilities offered by currents of very high frequency and observations which I casually made while pursuing experiments with alternating currents, as well as the stimulating influence of the work of Hertz and of views boldly put forth by Oliver Lodge, determined me some time during 1889 to enter a systematic investigation of high frequency phenomena, and the results soon reached were such as to justify further efforts towards providing the laboratory with efficient means for carrying on the research in this particular field, which has proved itself so fruitful since. As a consequence alternators of special design were constructed and various arrangements for converting ordinary into high frequency currents perfected, both of which were duly described and are now -I assume-familiar.

High Frequency Oscillators for Electro-Therapeutic and Other Purposes

Tesla's autobiographical legacy, essential reading for anyone seeking to penetrate the inventor's complex personality and mysterious life. He retells the story of his Faustian quest for the electric motor the experts said could never be built, which nearly cost him his sanity.

Nikola Tesla

Papers

Apparatus for transmitting electrical energy.

Art of transmitting electrical energy through the natural mediums.

Apparatus for transmission of electrical energy.

High Frequency Oscillators for Electro-Therapeutic and Other Purposes

My Inventions: The Autobiography of Nikola Tesla