A Review of Methods and Challenges for Improvement in Efficiency and Distance for Wireless Power Transfer Applications

AbstractOver the past few years, interest and research in wireless power transfer (WPT) have been rapidly incrementing, and as an effect, this is a remarkable technology in many electronic devices, electric vehicles and medical devices. However, most of the applications have been limited to very close distances because of efficiency concerns. Even though the inductive power transfer technique is becoming relatively mature, it has not shown near-field results more than a few metres away transmission. This review is focused on two fundamental aspects: the power efficiency and the transmission distance in WPT systems. Introducing the principles and the boundaries, scientific articles will be reviewed and discussed in terms of their methods and respective challenges. This paper also shows more important results in efficiency and distance obtained, clearly explaining the theory behind and obstacles to overcome. Furthermore, an overlook in other aspects and the latest research studies for this technology will be given. Moreover, new issues have been raised including safety and security.

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Single-Tube and Multi-Turn Coil Near-Field Wireless Power Transfer for Low-Power Home Appliances

Energies ◽

10.3390/en11081969 ◽

2018 ◽

Vol 11 (8) ◽

pp. 1969 ◽

Cited By ~ 3

Author(s):

Aqeel Jawad ◽

Rosdiadee Nordin ◽

Sadik Gharghan ◽

Haider Jawad ◽

Mahamod Ismail ◽

...

Keyword(s):

Low Power ◽

Power Efficiency ◽

Copper Wire ◽

Near Field ◽

Wireless Power Transfer ◽

Battery Life ◽

Total System ◽

Power Transfer ◽

Wireless Power ◽

Single Tube

Single-tube loop coil (STLC) and multi-turn copper wire coil (MTCWC) wireless power transfer (WPT) methods are proposed in this study to overcome the challenges of battery life during low-power home appliance operations. Transfer power, efficiency, and distance are investigated for charging mobile devices on the basis of the two proposed systems. The transfer distances of 1–15 cm are considered because the practicality of this range has been proven to be reliable in the current work on mobile device battery charging. For STLC, the Li-ion battery is charged with total system efficiencies of 86.45%, 77.08%, and 52.08%, without a load, at distances of 2, 6, and 15 cm, respectively. When the system is loaded with 100 Ω at the corresponding distances, the transfer efficiencies are reduced to 80.66%, 66.66%, and 47.04%. For MTCWC, the battery is charged with total system efficiencies of 88.54%, 75%, and 52.08%, without a load, at the same distances of 2, 6, and 15 cm. When the system is loaded with 100 Ω at the corresponding distances, the transfer efficiencies are drastically reduced to 39.52%, 33.6%, and 15.13%. The contrasting results, between the STLC and MTCWC methods, are produced because of the misalignment between their transmitters and receiver coils. In addition, the diameter of the MTCWC is smaller than that of the STLC. The output power of the proposed system can charge the latest smartphone in the market, with generated output powers of 5 W (STLC) and 2 W (MTCWC). The above WPT methods are compared with other WPT methods in the literature.

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