Enhancing wireless charging efficiency: addressing metal interference through advanced electromagnetic analysis and detection techniques

Huimin Han; Mughair Aslam Bhatti; Huimin Han; Mughair Aslam Bhatti

doi:10.48130/wpt-0024-0006

Wireless charging is an emerging technology that is quickly gaining popularity due to the potential to provide wireless power transmission for several gadgets. Nonetheless, the use of metallic objects is capable of greatly disrupting the effectiveness and reliability of wireless charging systems. This advanced technology involves the transmission of electrical energy between a charging station and the target device through the air gap with the help of techniques like magnetic coupling and magnetic resonance. These methods are appropriate for recharging devices with large batteries such as hand-held communication devices and electric vehicles. In the case of wireless charging, the application of metal foreign objects inside the energy transmission field causes complicated electromagnetic coupling because of the high-frequency electromagnetic field. These metallic interferences cause a change in the equivalent impedance of the transmitting coil; thereby, reducing the current at the transmitting end and consequently the charging efficiency. To this end, it is necessary to carry out a detailed investigation of the features of the wireless charging process in cases where metal objects are present. This includes studying the particular electromagnetic processes that take place and finding effective ways of identifying and preventing the effects of the metal foreign objects. This way, it is possible to provide for the maintenance of the required level of energy transmission in the systems of wireless charging.

HTML

Introduction

In the constantly developing area of wireless charging technology, one of the main issues is the existence of metal objects in the charging area^[1]. These objects can greatly influence the performance and reliability of wireless charging systems, resulting in overheating, energy dissipation, and even destruction of the charged devices. To this end, several techniques of metal foreign object detection (FOD) have been proposed each of which provides different ways of improving the efficiency of wireless charging. Thus, by analyzing these latest innovations, the goal is to give an overview of the current technologies, their strengths and weaknesses, and their applications. This research will explore a range of metal foreign object detection methodology applications. These methods include, but are not limited to, inductive sensing, capacitive sensing, and advanced imaging techniques. Each method will be examined in detail, focusing on its technical specifications, operational mechanisms, and suitability for different wireless charging scenarios^[2,3]. Additionally, the analysis will cover emerging technologies that promise to enhance detection accuracy and system integration. The advantages and disadvantages of each detection method will be critically analyzed. Key factors such as detection sensitivity, response time, cost-effectiveness, ease of integration, and compatibility with existing wireless charging infrastructure will be considered. This comprehensive evaluation will help identify the most effective and practical solutions for enhancing wireless charging efficiency^[4,5].

Today's FOD methods can be classified into metal FOD and living organism FOD. Although metal detection has been researched for a long time, research on detecting living organisms is still in its infancy. The majority of the research has been done on additional sensors such as thermal cameras, X-rays, pressure sensors, radars, and heat sensors. However, these methods are not easily compatible with magnetic couplers and are sensitive to the environment, thus giving false alarms. There has been a suggestion for a less complex and cheaper technique of using comb capacitors to detect living organisms. In high-power wireless power transmission systems, comb capacitor-based detection devices have been introduced and analyzed, especially for structural parameters and capacitance spacing. Parallel resonant circuits and integral circuits are intended for the detection of living organisms due to their impact on comb capacitors.

For metal foreign object detection, detector coil arrays are used due to their low cost and high integration. Studies have been made on the coil array configuration, the absence of blind area in detection, and the reliability of detection. Some of the active detection schemes that have been suggested to overcome the problems associated with passive detection schemes include impedance changes. These active schemes include the use of an excitation source on the detection coil, proper coil design to reduce blind areas, and the use of high-sensitivity frequencies that are slightly off the resonance point. It is impossible to avoid misalignment between the location of electric vehicles and ground-mounted power transmitters. To reduce this effect, techniques involving passive sensing coils and voltage vector decomposition have been suggested. In addition, non-cooperative MOD mechanisms for the safe operation of WEVC systems are used in the case of wireless electric vehicle charging. Optimal positioning of the sensing coils, size variation of the patch coils, and correct polarity arrangements reduce the blind zones and adjust to the magnetic field of the DD coils.

Moreover, the research will include case studies and examples from recent patent filings to illustrate how these detection methods have been implemented in real-world applications. These examples will provide valuable insights into the practical challenges and benefits associated with different detection technologies, highlighting their impact on improving wireless charging systems. This research aims to provide a thorough overview of metal foreign object detection methods from the perspective of patent applications, focusing on their role in enhancing wireless charging efficiency. By understanding the strengths and limitations of various detection technologies, industry professionals and researchers can make informed decisions about the most suitable approaches for their specific needs, ultimately contributing to the advancement and reliability of wireless charging solutions.

Application level and key issues of wireless power transmission technology

With the rapid application of wireless power transmission technology in many fields, this article reviews the research results at home and abroad over the past 10 years and explains the current application level of this technology in eight major fields: home electronic devices, smart homes, medical equipment, transportation, industrial robots, the Internet of Things, underwater detection equipment, and aerospace^[44]. It also summarizes the difficult problems to be solved in each field. Table 1 is a comparative analysis of this technology in different application fields.

Table 1. Comparative analysis of wireless power transmission technology in different application fields.

Application field	Key benefits	Key challenges	Efficiency	Cost	Examples of use
Consumer electronics	Convenience and mobility	Limited range, slower charging	Moderate	Low to moderate	Wireless charging pads for phones, tablets
Electric eehicles	Reduces the need for plug-in charging	High infrastructure cost, efficiency loss	Moderate to high	High	Static and dynamic wireless charging stations
Medical eevices	No wires, reducing infection risk	Power transfer limitations, regulatory hurdles	Low to moderate	High	Implants, wearable medical devices
Industrial eutomation	Flexibility, reduced wear on connectors	Interference, high initial setup cost	High	High	Automated guided vehicles (AGVs), robotics
Military	Reduced need for fuel transport	Security risks, high-tech implementation	Moderate	Very high	Remote charging of UAVs, field equipment
Space exploration	Enables long-distance energy transfer	Extreme environmental conditions, tech reliability	Low to moderate	Very high	Powering satellites, rovers
Smart homes	Enhanced user experience, convenience	Interference with other devices, efficiency	Low to moderate	Low to moderate	Wireless charging for smart home devices
Wearable technology	Improved user experience, flexibility	Battery life limitations, power transfer efficiency	Low to moderate	Low to moderate	Fitness trackers, smartwatches

Consumer electronics

The use of wireless charging has proven to be very convenient and portable in the sense that consumers are not restricted to the use of cables and sockets^[45−48]. This technology is mostly used in charging pads for charging smartphones and tablets. However, major disadvantages encompass lower power delivery, as well as the restricted area of coverage and charging capabilities as compared to a wired connection. It is mildly efficient, so it is relatively practical to use it regularly without a huge loss of power^[49,50]. The expenses required in this field for wireless charging solutions are relatively low to moderate for the broad consumer market^[51−54].

Electric vehicles
In the context of EVs' use, wireless charging decreases the dependency on plug-in technologies, which makes the process more accessible^[55]. It can be installed in static and dynamic charging stations as per electric vehicle requirements, charging process may occur while the electric vehicle is parked or even when it is in motion. However, it is not devoid of challenges; the main ones being the high infrastructure cost as well as the efficiency incompatibility whereby the structure undergoes dramatic efficiency loss during the power transfer^[56−58]. On efficiency, it ranges from moderate to high based on the level of implementation, however on cost, it is high because it involves the use of advanced technology and infrastructure^[59].

Medical devices
In medical devices, wireless charging removes wires and thus cuts the spread of infection through invasive charging solutions. This is apparent, especially in connection with implants and any other wearable healthcare devices^[60−62]. However, in turn, it is a challenge regarding power transfer and is subject to strict legislation that sets back its use. The level of accuracy is comparatively low to moderate; however, the improvement of the patient safety conditions and device usability fully justifies the mentioned high costs^[63].

Industrial automation
Wireless charging in industrial automation is advantageous as it enhances mobility, cuts down the connections' susceptibility to fatigue, and plays a critical role in the durability of industrial automation systems. Some of the real-life applications among them are the use in AGVs and robotics^[64−66]. The main drawbacks are the disturbance by other electrical pertinent systems and high initial investments. On the other hand, the efficiency of wireless charging in these applications is quite high hence the technology is worth the investment irrespective of the costs incurred^[67−70].

Military
This method of charging is advantageous in military operations that entail charging a large number of batteries; it eliminates the need for a source of fuel hence improving the movement of operations logistics and overall readiness. It is for charging UAVs and other field appliances from a distance using electrical energy^[71−73]. Nonetheless, its application is mainly security-sensitive and requires a high level of technical requirements. The degree of efficiency is rather low but the costs are rather significant because the production of army equipment is highly specialized and rather expensive^[74].

Space exploration
Wireless charging in space exploration is crucial in charging satellites and rovers, and energy transfer through long distances is vital. Severe environmental factors as well as the requirements that must be met in terms of technology are the main challenges^[75−78]. The operating efficiency is often low to average, primarily because of the severe environment and distance over which operations are managed, though the overall cost is very high because of the technology incorporating sophisticated equipment and materials^[79,80].

Smart homes
For smart homes, wireless charging helps to improve their usability by removing the need for untidy wires and enabling power to many devices. Nevertheless, one must note the issue of the interference with other electrical appliances and the efficiency which may not be present at an optimum level at all times^[81−83]. The cost is considered low to moderate, which will enable owners to increase the intelligibility of their house without massive expenses^[84−87].

Wearable technology
Wireless wearable technology enhances user experience by making it flexible and less required to be recharged through normal methods^[88−90]. Some of the applicable devices are body monitoring devices such as fitness trackers and smartwatches. Some of them are; the use of batteries and the efficiency at which power is transferred between the batteries^[91−95]. Nonetheless, the cost is relatively low to moderate while the gains in ease of use for clients and capability of the devices are high^[96].

Related issues in the development of wireless power transmission technology

Wireless power transmission technology has a wide range of applications and has achieved relevant industrialized results from low power to high power, from low frequency to high frequency, and from static to dynamic^[97−99]. To further promote the rapid development of wireless power supply-related industries, we should focus on practical application fields, speed up the solution of key common problems in wireless charging technology, and focus on the wireless charging industry chain to speed up the breakthrough of bottleneck problems that restrict industrial development^[100−102].

Key common issues in the application of wireless power transmission technology in various fields

Multi-objective parameter combination optimization
The key parameters of wireless power transmission systems include time-varying parameters such as quality factors, coupling coefficient, transmission impedance, and power frequency^[103−105]. Some scholars have studied the influence relationship between transmission parameter combinations, but all are qualitative analyses^[106]. In the overall design of wireless power transmission systems, to maximize energy efficiency, the analytical relationship between each parameter and energy efficiency and the quantitative relationship between parameters are important aspects of theoretical research on wireless power technology^[107].

Robustness of electromagnetic energy transfer
In static wireless charging systems, foreign metal objects (including magnetic metals) are ingested into the gap of the coupling mechanism or living things such as cats and dogs invade. In dynamic wireless power supply systems, the vibration of the electromagnetic coupling structure and lateral displacement of the receiving coil are inevitable in practical applications and the severity of the impact on the system varies under different environmental conditions^[108]. A slight impact will cause the quality of the receiving body to decline, and in severe cases, the power device of the receiving body will be damaged and stop working^[109].

Therefore, studying the topological structure of the magnetic coupling system that is resistant to external disturbances and the highly robust control method to ensure stable and reliable power reception of the power-receiving object is a basic requirement for the industrialization of dynamic wireless power transmission.

Multi-source and multi-load technology
To meet the power supply requirements of loads in different application scenarios, the electromagnetic coupling system structure has three forms: one-to-one, one-to-many, and many-to-many. Therefore, in complex environments, the coordinated management of multiple loads and multiple transmitters, the automatic charging and discharging of loads, and the mutual influence between loads are issues that need to be solved in the application of wireless power transmission technology^[110].

Electromagnetic environmental biosafety
The biological safety of the electromagnetic environment has always been an important issue in the industrial application of wireless power transmission technology.

In 2000, the Jet Propulsion Laboratory of the United States first raised the safety issue of wireless power transmission from solar power satellites. If people and other living things are in an electromagnetic environment that exceeds the safety limit for a long time, their biological functions will be damaged. The research team of Nagoya Institute of Technology in Japan conducted a three-level study on electromagnetic safety based on the MIT wireless power transmission system model^[111].

Some scholars have analyzed the S parameters of the system based on the 2/3 muscle tissue equivalent cylindrical model and concluded that the system with an open coil is more affected by the human body than the system with a closed coil. Some scholars have used the quasi-static method to approximate the electric field distribution of the system and analyzed the safety of the system by calculating the specific absorption ratio (SAR) value of the human tissue equivalent model at a fixed point in the approximate electric field. Some scholars have used the quasi-static method to approximate the distribution of the system's electric field and magnetic field, respectively, and studied the electromagnetic safety of the system by calculating the SAR values based on several different human equivalent models^[112,113].

The Electromagnetic and Acoustic Experimental Center of the Swiss Federal Institute of Technology and the University of Washington in the United States conducted a comprehensive study on the electromagnetic environment of wireless power transmission systems with a coil diameter of 580 mm, and a frequency range of 1 to 20 MHz, and a small wireless power transmission system with a coil diameter range of 20 to 150 mm, a system power of 5 W, and a frequency of 100 kHz^[114,115].

There is little research in China on electromagnetic safety. Further research is needed on the impact of high-intensity magnetic fields on surrounding organisms in different application scenarios, especially the degree of harm to the human body.

Analysis on the current status of industrial development of wireless power transmission technology

Conclusions

This research has provided an in-depth analysis of the diverse technologies and methodologies for metal foreign object detection in the context of wireless power transmission (WPT). By evaluating approaches based on Q-factor, voltage, current, power loss, and temperature, the strengths and weaknesses of each method have been presented. The present investigation underscores the importance of combining multiple detection methods to mitigate the limitations inherent in individual approaches, thus enhancing the overall safety and efficiency of wireless charging systems. The analysis reveals that the integration of various detection techniques can substantially improve the reliability and performance of WPT systems. Methods such as Q-factor detection offer high precision but at a higher cost, while temperature-based methods are cost-effective but sensitive to environmental variations. Advanced techniques like infrared, image, and ultrasound detection provide high accuracy but require sophisticated processing algorithms. The significant increase in research activity, particularly from 2015 onwards, with notable contributions from China, highlights the growing academic and practical interest in optimizing WPT technologies. This is further corroborated by the surge in patent applications, indicating robust innovation and commercial potential in this field.

Future research directions

Multi-objective parameter optimization
Future research should focus on developing algorithms for optimizing multiple parameters simultaneously to enhance the efficiency and effectiveness of WPT systems. This includes balancing factors like power transfer efficiency, detection accuracy, and cost.

Robust electromagnetic energy transmission
Investigating methods to improve the robustness of electromagnetic energy transfer, especially in dynamic environments with varying distances and orientations between the transmitter and receiver, is crucial.

Multi-source and multi-load technology
Developing WPT systems capable of efficiently handling multiple power sources and loads will be essential for applications in smart homes, industrial automation, and electric vehicles.

Biological safety of electromagnetic environments
Comprehensive studies on the long-term biological effects of electromagnetic fields generated by WPT systems are necessary to ensure safety standards are met and to alleviate public concerns.

Standardization of WPT products
Establishing global standards for WPT products will facilitate interoperability, improve consumer confidence and accelerate the adoption of wireless charging technologies across various industries.

Technology implementations for improvements

Advanced sensor integration
Incorporating advanced sensors and machine learning algorithms to enhance the accuracy and reliability of metal foreign object detection systems. This could involve real-time data analysis and adaptive control mechanisms.

Hybrid detection systems
Developing hybrid detection systems that combine multiple detection methods (e.g., Q-factor, infrared, and ultrasound) to leverage the advantages of each approach while mitigating their individual limitations.

Improved calibration techniques
Enhancing calibration techniques for voltage, current, and impedance detection methods to reduce false positives and improve the precision of anomaly detection.

Miniaturization and cost reduction
Focusing on the miniaturization of detection circuits and sensors to reduce costs and integrate them seamlessly into compact and portable WPT devices.

Integration with IoT
Leveraging the Internet of Things (IoT) to create intelligent WPT systems that can communicate with other devices, providing real-time status updates, diagnostics, and automated responses to detected anomalies.

By addressing these future research directions and implementing advanced technologies, the field of wireless power transmission can achieve significant advancements, ensuring efficient, safe, and ubiquitous power solutions that meet the growing demands of modern applications.

Author contributions

The authors confirm contribution to the paper as follows: investigation; resources; data curation; writing - original draft; supervision; project administration: Han H; conceptualization; methodology; software; validation; formal analysis; funding acquisition; formal analysis: Bhatti MA; writing - review & editing; visualization: Han H, Bhatti MA. Both authors reviewed the results and approved the final version of the manuscript.

[1]	Chen C, Huang X, Sun W, Tan L. 2014. Impact of metal obstacles on wireless power transmission system based coupled resonance. Transactions of China Electrotechnical Society 29(9):22−26 Google Scholar
[2]	Zhao ZM, Zhang YM, Chen KN. 2013. New progress of magnetically-coupled resonant wireless power transfer technology. Proceedings of the Chinese Society of Electrical Engineering 33:1−13 doi: 10.1201/b15548-3 CrossRef Google Scholar
[3]	Azad A, Kulyukin V, Pantic Z. 2019. Misalignment tolerant DWPT charger for EV roadways with integrated foreign object detection and driver feedback system. 2019 IEEE Transportation Electrification Conference and Expo (ITEC), Detroit, MI, USA, 19−21 June, 2019. Detroit, MI, USA: IEEE. pp. 1−5. doi: 10.1109/ITEC.2019.8790600
[4]	Jeong SY, Kwak HG, Jang GC, Choi SY, Rim CT. 2018. Dual-purpose nonoverlapping coil sets as metal object and vehicle position detections for wireless stationary EV chargers. IEEE Transactions on Power Electronics 33:7387−97 doi: 10.1109/TPEL.2017.2765521 CrossRef Google Scholar
[5]	Sonnenberg T, Stevens A, Dayerizadeh A, Lukic S. 2019. Combined foreign object detection and live object protection in wireless power transfer systems via real-time thermal camera analysis. 2019 IEEE Applied Power Electronics Conference and Exposition (APEC). Anaheim, CA, USA, 17−21 March, 2019. USA: IEEE. pp. 1547−52. doi: 10.1109/APEC.2019.8721804
[6]	Liou CY, Kuo CJ, Mao SG. 2016. Wireless powering system with backside metallic plates using electric- and magnetic-coupling mechanisms. 2016 IEEE International Symposium on Radio-Frequency Integration Technology (RFIT), Taipei, China, 24−26 August, 2016. USA: IEEE. pp. 1−3. doi: 10.1109/RFIT.2016.7578158
[7]	Liu X, Liu C, Han W, Pong PWT. 2019. Design and implementation of a multi-purpose TMR sensor matrix for wireless electric vehicle charging. IEEE Sensors Journal 19:1683−92 doi: 10.1109/JSEN.2018.2883708 CrossRef Google Scholar
[8]	Kikuchi H. 2013. Metal-loop effects in wireless power transfer systems analyzed by simulation and theory. 2013 IEEE Electrical Design of Advanced Packaging Systems Symposium (EDAPS), Nara, Japan, 12−15 December, 2013. USA: IEEE. pp. 201−4. doi: 10.1109/EDAPS.2013.6724424
[9]	Low ZN, Casanova JJ, Maier PH, Taylor JA, Chinga RA, et al. 2010. Method of load/fault detection for loosely coupled planar wireless power transfer system with power delivery tracking. IEEE Transactions on Industrial Electronics 57:1478−86 doi: 10.1109/TIE.2009.2030821 CrossRef Google Scholar
[10]	Kuyvenhoven N, Dean C, Melton J, Schwannecke J, Umenei AE. 2011. Development of a foreign object detection and analysis method for wireless power systems. 2011 IEEE Symposium on Product Compliance Engineering Proceedings, San Diego, CA, USA, 10-12 October 2011. USA: IEEE. pp. 1−6. doio: 10.1109/PSES.2011.6088250
[11]	Lan L, Ting NM, Aldhaher S, Kkelis G, Kwan CH, et al. 2018. Foreign object detection for wireless power transfer. 2018 2 ^nd URSI Atlantic Radio Science Meeting (AT-RASC), Gran Canaria, Spain, 28 May − 1 June 2018. USA: IEEE. pp. 1−2. doi: 10.23919/URSI-AT-RASC.2018.8471551
[12]	Liu X, Pong PWT, Liu C. 2018. Dual measurement of current and temperature using a single tunneling magnetoresistive sensor. 2018 IEEE SENSORS, New Delhi, India, 28−31 October 2018. USA: IEEE. pp. 1−4. doi: 10.1109/ICSENS.2018.8589743
[13]	Sonapreetha MR, Jeong SY, Choi SY, Rim CT. 2015. Dual-purpose non-overlapped coil sets as foreign object and vehicle location detections for wireless stationary EV chargers. 2015 IEEE PELS Workshop on Emerging Technologies: Wireless Power (2015 WoW), Daejeon, Korea (South), 5−6 June, 2015. USA: IEEE. pp. 1−7. doi: 10.1109/WoW.2015.7132803
[14]	Jeong SY, Thai VX, Park JH, Rim CT. 2019. Self-inductance-based metal object detection with mistuned resonant circuits and nullifying induced voltage for wireless EV chargers. IEEE Transactions on Power Electronics 34:748−58 doi: 10.1109/TPEL.2018.2813437 CrossRef Google Scholar
[15]	Xiang L, Zhu Z, Tian J, Tian Y. 2019. Foreign object detection in a wireless power transfer system using symmetrical coil sets. IEEE Access 7:44622−31 doi: 10.1109/ACCESS.2019.2908866 CrossRef Google Scholar
[16]	Thai VX, Jang GC, Jeong SY, Park JH, Kim YS, et al. 2020. Symmetric sensing coil design for the blind-zone free metal object detection of a stationary wireless electric vehicles charger. IEEE Transactions on Power Electronics 35:3466−77 doi: 10.1109/TPEL.2019.2936249 CrossRef Google Scholar
[17]	Thai VX, Park JH, Jeong SY, Rim CT, Kim YS. 2020. Equivalent-circuit-based design of symmetric sensing coil for self-inductance-based metal object detection. IEEE Access 8:94190−203 doi: 10.1109/ACCESS.2020.2995210 CrossRef Google Scholar
[18]	Cheng B, Lu J, Zhang Y, Pan G, Chabaan R, et al. 2020. A metal object detection system with multilayer detection coil layouts for electric vehicle wireless charging. Energies 13:2960 doi: 10.3390/en13112960 CrossRef Google Scholar
[19]	Tan L, Li J, Chen C, Yan C, Guo J, et al. 2016. Analysis and performance improvement of WPT systems in the environment of single non-ferromagnetic metal plates. Energies 9:576 doi: 10.3390/en9080576 CrossRef Google Scholar
[20]	Li C, Cao J, Zhang H. 2015. Modeling and analysis for magnetic resonance coupling wireless power transmission systems under influence of non-ferromagnetic metal. Automation of Electric Power Systems 39:152−57 doi: 10.7500/AEPS20150319007 CrossRef Google Scholar
[21]	Nguyen DH, Chapman A. 2021. The potential contributions of universal and ubiquitous wireless power transfer systems towards sustainability. International Journal of Sustainable Engineering 14:1780−90 doi: 10.1080/19397038.2021.1988187 CrossRef Google Scholar
[22]	Team CAI. 2017. Europe and the future for WPT: European contributions to wireless power transfer technology. IEEE Microwave Magazine 18:56−87 doi: 10.1109/MMM.2017.2680078 CrossRef Google Scholar
[23]	Jawad AM, Nordin R, Gharghan SK, Jawad HM, Ismail M. 2017. Opportunities and challenges for near-field wireless power transfer: a review. Energies 10:1022 doi: 10.3390/en10071022 CrossRef Google Scholar
[24]	Barman SD, Reza AW, Kumar N, Karim ME, Munir AB. 2015. Wireless powering by magnetic resonant coupling: recent trends in wireless power transfer system and its applications. Renewable and Sustainable Energy Reviews 51:1525−52 doi: 10.1016/j.rser.2015.07.031 CrossRef Google Scholar
[25]	Mohsan SAH, Khan MA, Mazinani A, Alsharif MH, Cho HS. 2022. Enabling underwater wireless power transfer towards sixth generation (6G) wireless networks: opportunities, recent advances, and technical challenges. Journal of Marine Science and Engineering 10:1282 doi: 10.3390/jmse10091282 CrossRef Google Scholar
[26]	Chhawchharia S, Sahoo SK, Balamurugan M, Sukchai S, Yanine F. 2018. Investigation of wireless power transfer applications with a focus on renewable energy. Renewable and Sustainable Energy Reviews 91:888−902 doi: 10.1016/j.rser.2018.04.101 CrossRef Google Scholar
[27]	Suja S, Sathish Kumar T. 2013. Solar based wireless power transfer system. 2013 International Conference on Computation of Power, Energy, Information and Communication (ICCPEIC), Chennai, India, 17−18 April 2013. USA: IEEE. pp. 93−99. doi: 10.1109/ICCPEIC.2013.6778505
[28]	Khalid R, Naeem M, Ejaz W. 2022. Autonomous aerial networks with wireless power transfer: resource optimization, standardization, and challenges. IEEE Communications Standards Magazine 6:24−31 doi: 10.1109/MCOMSTD.0001.2200022 CrossRef Google Scholar
[29]	Yoo S, Lee J, Joo H, Sunwoo SH, Kim S, et al. 2021. Wireless power transfer and telemetry for implantable bioelectronics. Advanced Healthcare Materials 10(17):2100614 doi: 10.1002/adhm.202100614 CrossRef Google Scholar
[30]	El-Shahat A, Ayisire E, Wu Y, Rahman M, Nelms D. 2019. Electric vehicles wireless power transfer state-of-the-art. Energy Procedia 162:24−37 doi: 10.1016/j.egypro.2019.04.004 CrossRef Google Scholar
[31]	Panchal C, Stegen S, Lu J. 2018. Review of static and dynamic wireless electric vehicle charging system. Engineering Science and Technology, an International Journal 21:922−37 doi: 10.1016/j.jestch.2018.06.015 CrossRef Google Scholar
[32]	Moyssides PG. 2014. The anticipated longitudinal forces by the Biot-Savart-Grassmann-Lorentz force law are in complete agreement with the longitudinal Ampère forces. The European Physical Journal Plus 129:34 doi: 10.1140/epjp/i2014-14034-2 CrossRef Google Scholar
[33]	Angurala M. 2023. A review on energy efficient techniques for wireless sensor networks. International Journal of Intelligent Systems and Applications in Engineering 11:171−82 Google Scholar
[34]	Giuliani G. 2008. A general law for electromagnetic induction. Europhysics Letters 81(6):60002 doi: 10.1209/0295-5075/81/60002 CrossRef Google Scholar
[35]	Coufal O. 2017. Faraday's law of electromagnetic induction in two parallel conductors. International Journal of Applied Electromagnetics and Mechanics 54:263−80 doi: 10.3233/jae-160123 CrossRef Google Scholar
[36]	Okasili I, Elkhateb A, Littler T. 2022. A review of wireless power transfer systems for electric vehicle battery charging with a focus on inductive coupling. Electronics 11:1355 doi: 10.3390/electronics11091355 CrossRef Google Scholar
[37]	Degen C. 2021. Inductive coupling for wireless power transfer and near-field communication. EURASIP Journal on Wireless Communications and Networking 2021:121 doi: 10.1186/s13638-021-01994-4 CrossRef Google Scholar
[38]	Thiagarajan K, Deepa T. 2023. A comprehensive review of high-frequency transmission inverters for magnetic resonance inductive wireless charging applications in electric vehicles. IETE Journal of Research 69:2761−71 doi: 10.1080/03772063.2021.1905089 CrossRef Google Scholar
[39]	Tran MT, Thekkan S, Polat H, Tran DD, El Baghdadi M, et al. 2023. Inductive wireless power transfer systems for low-voltage and high-current electric mobility applications: review and design example. Energies 16:2953 doi: 10.3390/en16072953 CrossRef Google Scholar
[40]	Kamarudin SI, Ismail A, Sali A, Ahmad MY, Ismail I, et al. 2022. 5G magnetic resonance coupling planar spiral coil wireless power transfer. Trends in Sciences 20:3444 doi: 10.48048/tis.2023.3444 CrossRef Google Scholar
[41]	Uddin MK, Ramasamy G, Mekhilef S, Ramar K, Lau YC. 2014. A review on high frequency resonant inverter technologies for wireless power transfer using magnetic resonance coupling. 2014 IEEE Conference on Energy Conversion (CENCON). Johor Bahru, Malaysia, 13−14 October 2014. USA: IEEE. pp. 412−17. doi: 10.1109/CENCON.2014.6967539
[42]	Butler JC, Vigliotti AJ, Verdi FW, Walsh SM. 2002. Wireless, passive, resonant-circuit, inductively coupled, inductive strain sensor. Sensors and Actuators A: Physical 102:61−66 doi: 10.1016/s0924-4247(02)00342-4 CrossRef Google Scholar
[43]	Zheng Y, Wei Z, Yan H, Huang L, Gao Y. 2022. Impedance matching method for magnetic resonance coupling human body communication. 2022 IEEE 10 ^th Asia-Pacific Conference on Antennas and Propagation (APCAP), Xiamen, China, 4−7 November 2022. USA: IEEE. pp. 1−2. doi: 10.1109/APCAP56600.2022.10069779
[44]	Fisher TM, Farley KB, Gao Y, Bai H, Tse ZTH. 2014. Electric vehicle wireless charging technology: a state-of-the-art review of magnetic coupling systems. Wireless Power Transfer 1:87−96 doi: 10.1017/wpt.2014.8 CrossRef Google Scholar
[45]	Huang Z, Guan T, Wang Z, Wei J, Wang S, et al. 2022. Maximum efficiency tracking design of wireless power transmission system based on machine learning. Energy Reports 8:447−55 doi: 10.1016/j.egyr.2022.10.139 CrossRef Google Scholar
[46]	Choi BG, Kim YS. 2021. New structure design of ferrite cores for wireless electric vehicle charging by machine learning. IEEE Transactions on Industrial Electronics 68:12162−72 doi: 10.1109/TIE.2020.3047041 CrossRef Google Scholar
[47]	Ma F, Liu X, Ansari N. 2022. Electromagnetic radiation safety on far-field wireless power transfer in IoT. GLOBECOM 2022 - 2022 IEEE Global Communications Conference, Rio de Janeiro, Brazil, 4−8 December 2022. USA: IEEE. pp. 4995−5000. doi: 10.1109/GLOBECOM48099.2022.10001490
[48]	He S, Hu K, Li S, Fu L, Gu C, et al. 2024. A robust RF-based wireless charging system for dockless bike-sharing. IEEE Transactions on Mobile Computing 23:2395−406 doi: 10.1109/TMC.2023.3255980 CrossRef Google Scholar
[49]	Katsidimas I, Kerimakis E, Nikoletseas S. 2019. Placement optimization in wireless charging systems under the vector model. 15 ^th International Conference on Distributed Computing in Sensor Systems (DCOSS). Santorini, Greece, 29−31 May 2019. USA: IEEE. pp. 473−80. doi: 10.1109/DCOSS.2019.00093
[50]	Ahmad A, Alam MS, Chabaan R. 2018. A comprehensive review of wireless charging technologies for electric vehicles. IEEE Transactions on Transportation Electrification 4:38−63 doi: 10.1109/TTE.2017.2771619 CrossRef Google Scholar
[51]	Joseph PK, Elangovan D. 2018. A review on renewable energy powered wireless power transmission techniques for light electric vehicle charging applications. Journal of Energy Storage 16:145−55 doi: 10.1016/j.est.2017.12.019 CrossRef Google Scholar
[52]	Zeng Y, Clerckx B, Zhang R. 2017. Communications and signals design for wireless power transmission. IEEE Transactions on Communications 65:2264−90 doi: 10.1109/TCOMM.2017.2676103 CrossRef Google Scholar
[53]	Huda SMA, Arafat MY, Moh S. 2022. Wireless power transfer in wirelessly powered sensor networks: a review of recent progress. Sensors 22:2952 doi: 10.3390/s22082952 CrossRef Google Scholar
[54]	Ding J, Liu W, Chih-Lin I, Zhang H, Mei H. 2020. Advanced progress of optical wireless technologies for power industry: an overview. Applied Sciences 10:6463 doi: 10.3390/app10186463 CrossRef Google Scholar
[55]	Lu X, Wang P, Niyato D, Kim DI, Han Z. 2016. Wireless charging technologies: fundamentals, standards, and network applications. IEEE Communications Surveys & Tutorials 18:1413−52 doi: 10.1109/COMST.2015.2499783 CrossRef Google Scholar
[56]	Bidkar R. 2012. Space Based Solar Power (SBSP): an emerging technology. 2012 IEEE 5 ^th India International Conference on Power Electronics (IICPE), Delhi, India, 6−8 December 2012. USA: IEEE. pp. 1−4. doi: 10.1109/IICPE.2012.6450440
[57]	Mishra RK, Mishra AK. 2023. Space based Solar Power: feasibility Microwave based wireless power system. Journal of Marine Science and Research 2:1−5 doi: 10.58489/2836-5933/005 CrossRef Google Scholar
[58]	Sabarish P, Hubert Tony Raj L, Ramprakash G, Karthick R. 2020. An energy efficient microwave based wireless solar power transmission system. IOP Conference Series: Materials Science and Engineering 937:012013 doi: 10.1088/1757-899x/937/1/012013 CrossRef Google Scholar
[59]	Li B, Liu S, Zhang HL, Hu BJ, Zhao D, et al. 2019. Wireless power transfer based on microwaves and time reversal for indoor environments. IEEE Access 7:114897−908 doi: 10.1109/ACCESS.2019.2936250 CrossRef Google Scholar
[60]	Karimi MJ, Schmid A, Dehollain C. 2021. Wireless power and data transmission for implanted devices via inductive links: a systematic review. IEEE Sensors Journal 21:7145−61 doi: 10.1109/JSEN.2021.3049918 CrossRef Google Scholar
[61]	Yeh ER, Choi J, Prelcic NG, Bhat CR, Heath RW Jr. 2016. Security in automotive radar and vehicular networks. Microwave Journal 60(5):148−64 Google Scholar
[62]	Zeng Y, Lu C, Liu R, He X, Rong C, et al. 2023. Wireless power and data transfer system using multidirectional magnetic coupler for swarm AUVs. IEEE Transactions on Power Electronics 38:1440−44 doi: 10.1109/TPEL.2022.3214318 CrossRef Google Scholar
[63]	Gu X, Hemour S, Wu K. 2022. Far-field wireless power harvesting: nonlinear modeling, rectenna design, and emerging applications. Proceedings of the IEEE 110:56−73 doi: 10.1109/JPROC.2021.3127930 CrossRef Google Scholar
[64]	Moisello E, Liotta A, Malcovati P, Bonizzoni E. 2023. Recent trends and challenges in near-field wireless power transfer systems. IEEE Open Journal of the Solid-State Circuits Society 3:197−213 doi: 10.1109/OJSSCS.2023.3313575 CrossRef Google Scholar
[65]	Albreem MA, Sheikh AM, Alsharif MH, Jusoh M, Mohd Yasin MN. 2021. Green Internet of Things (GIoT): applications, practices, awareness, and challenges. IEEE Access 9:38833−58 doi: 10.1109/ACCESS.2021.3061697 CrossRef Google Scholar
[66]	Pravin AMA, Narayanan AG, Balaganesh R, Manikandan P, Saravanan J. 2014. Wireless power transmission using indcutive coupling. International Journel of Emerging Technology and Computer Science 8(1):126−30 Google Scholar
[67]	Biswa R. 2012. Feasibility of wireless power transmission. Seminar Report. Electronics and Communication Engineering, College of Science and Technology, Rinchending, Phuentsholing. pp. 1−23
[68]	Soares L, Wang H. 2022. A study on renewed perspectives of electrified road for wireless power transfer of electric vehicles. Renewable and Sustainable Energy Reviews 158:112110 doi: 10.1016/j.rser.2022.112110 CrossRef Google Scholar
[69]	Liu W, Chau K, Tian X, Wang H, Hua Z. 2023. Smart wireless power transfer—opportunities and challenges. Renewable and Sustainable Energy Reviews 180:113298 doi: 10.1016/j.rser.2023.113298 CrossRef Google Scholar
[70]	Wang C, Ma Z. 2016. Design of wireless power transfer device for UAV. 2016 IEEE International Conference on Mechatronics and Automation, Harbin, China, 7−10 August, 2016. USA: IEEE. pp. 2449−54. doi: 10.1109/ICMA.2016.7558950
[71]	Suh IS, Kim J. 2013. Electric vehicle on-road dynamic charging system with wireless power transfer technology. 2013 International Electric Machines & Drives Conference, Chicago, IL, USA, 12−15 May 2013. USA: IEEE. pp. 234−40. doi: 10.1109/IEMDC.2013.6556258
[72]	Ullah MA, Keshavarz R, Abolhasan M, Lipman J, Esselle KP, et al. 2022. A review on antenna technologies for ambient RF energy harvesting and wireless power transfer: designs, challenges and applications. IEEE Access 10:17231−67 doi: 10.1109/ACCESS.2022.3149276 CrossRef Google Scholar
[73]	Lin HT, Wu YC, Hsieh PH, Yang CH. 2017. Integration of energy-recycling logic and wireless power transfer for ultra-low-power implantables. 2017 IEEE International Symposium on Circuits and Systems (ISCAS). Baltimore, MD, USA, 28−31 May, 2017. USA: IEEE. pp. 1−4. doi: 10.1109/ISCAS.2017.8050378
[74]	Lu C, Rong C, Huang X, Hu Z, Tao X, et al. 2019. Investigation of negative and near-zero permeability metamaterials for increased efficiency and reduced electromagnetic field leakage in a wireless power transfer system. IEEE Transactions on Electromagnetic Compatibility 61:1438−46 doi: 10.1109/TEMC.2018.2865520 CrossRef Google Scholar
[75]	Raza U, Salam A. 2020. Zenneck waves in decision agriculture: an empirical verification and application in EM-based underground wireless power transfer. Smart Cities 3:308−40 doi: 10.3390/smartcities3020017 CrossRef Google Scholar
[76]	La Rosa R, Livreri P, Trigona C, Di Donato L, Sorbello G. 2019. Strategies and techniques for powering wireless sensor nodes through energy harvesting and wireless power transfer. Sensors 19:2660 doi: 10.3390/s19122660 CrossRef Google Scholar
[77]	Hui SYR. 2018. Technical and safety challenges in emerging trends of near-field wireless power transfer industrial guidelines. IEEE Electromagnetic Compatibility Magazine 7:78−86 doi: 10.1109/MEMC.0.8339551 CrossRef Google Scholar
[78]	Lin JC. 2021. Safety of wireless power transfer. IEEE Access 9:125342−47 doi: 10.1109/ACCESS.2021.3108966 CrossRef Google Scholar
[79]	Bi Z, Kan T, Mi CC, Zhang Y, Zhao Z, et al. 2016. A review of wireless power transfer for electric vehicles: prospects to enhance sustainable mobility. Applied Energy 179:413−25 doi: 10.1016/j.apenergy.2016.07.003 CrossRef Google Scholar
[80]	Triviño A, González-González JM, Aguado JA. 2021. Wireless power transfer technologies applied to electric vehicles: a review. Energies 14:1547 doi: 10.3390/en14061547 CrossRef Google Scholar
[81]	Ron Hui SY. 2016. Past, present and future trends of non-radiative wireless power transfer. CPSS Transactions on Power Electronics and Applications 1:83−91 doi: 10.24295/cpsstpea.2016.00008 CrossRef Google Scholar
[82]	Xie L, Shi Y, Hou YT, Sherali HD. 2012. Making sensor networks immortal: an energy-renewal approach with wireless power transfer. IEEE/ACM Transactions on Networking 20:1748−61 doi: 10.1109/TNET.2012.2185831 CrossRef Google Scholar
[83]	St John SA. 2017. Investigating wireless power transfer. Physics Education 52(5):055008 doi: 10.1088/1361-6552/aa7f44 CrossRef Google Scholar
[84]	Delichte SD, Lu YJ, Bobowski JS. 2018. Non-radiative mid-range wireless power transfer: an experiment for senior physics undergraduates. American Journal of Physics 86:623−32 doi: 10.1119/1.5037705 CrossRef Google Scholar
[85]	Sridhar B, Kathirvel C, Balamurugan SB, Hariprasad P. 2023. Design of efficient wireless charging pad deployment and maximizing the power transfer technique for an autonomous electric vehicle charging. 2023 Second International Conference on Electronics and Renewable Systems (ICEARS), Tuticorin, India, 2−4 March, 2023. USA: IEEE. pp. 347−54. doi: 10.1109/ICEARS56392.2023.10085244
[86]	Gonzalez M, Xu P, Dekimpe R, Schramme M, Stupia I, et al. 2023. Technical and ecological limits of 2.45-GHz wireless power transfer for battery-less sensors. IEEE Internet of Things Journal 10:15431−42 doi: 10.1109/jiot.2023.3263976 CrossRef Google Scholar
[87]	Li T, Wu L, Chen Z. 2015. Research overview on wireless power transmission technology. MATEC Web of Conferences 22:02021 doi: 10.1051/matecconf/20152202021 CrossRef Google Scholar
[88]	Wang Q, Li H. 2011. Research on the wireless power transmission system based on coupled magnetic resonances. 2011 International Conference on Electronics, Communications and Control (ICECC), Ningbo, China, 2011. pp. 2255−58. doi: 10.1109/ICECC.2011.6067744
[89]	Yang Q, Chen H, Xu G, Sun M, Fu W. 2010. Research progress in contactless power transmission technology. Transactions of China Electrotechnical Society 25(7):6−13 Google Scholar
[90]	Liu C, Wang F, Shi K, Wang X, Sun Z. 2014. Robust H_∞ control for satellite atti-tude control system with uncertainties and additive per-turbation. International Journal of Science 1(2):1−9 Google Scholar
[91]	Shi K, Sun Z, Liu C, Wang F. 2015. Design of microsatellite attitude control with multiplicative perturbation of controller. The 27 ^th Chinese Control and Decision Conference (2015 CCDC), Qingdao, China, 23−25 May 2015. USA: IEEE. pp. 491−95. doi: 10.1109/CCDC.2015.7161742
[92]	Li J. 2017. Research progress of wireless power transmission technology and the related problems. AIP Conference Proceedings 1820:090023 doi: 10.1063/1.4977407 CrossRef Google Scholar
[93]	Liu Y, Xiao J, Zhao X, Wu J, Du Y, et al. 2023. Development and application review on wireless power transmission technology. Technology of Electrical Engineering and Energy 42(2):48−67 doi: 10.12067/ATEEE2203007 CrossRef Google Scholar
[94]	Liu C, Wang F. 2014. In-orbit estimation of inertia parameters of target satellite after capturing the tracking satellite. Proceeding of the 11 ^th World Congress on Intelligent Control and Automation, Shenyang, China, 29 June − 4 July 2014. USA: IEEE. pp. 3942−47. doi: 10.1109/WCICA.2014.7053375
[95]	McSpadden JO, Mankins JC. 2002. Space solar power programs and microwave wireless power transmission technology. IEEE Microwave Magazine 3:46−57 doi: 10.1109/MMW.2002.1145675 CrossRef Google Scholar
[96]	Brown WC. 1996. The history of wireless power transmission. Solar Energy 56:3−21 doi: 10.1016/0038-092x(95)00080-b CrossRef Google Scholar
[97]	Huang H, Huang X, Tan L, Ding X. 2011. Research on transmitter and receiver of wireless power transmission based on magnetic resonance coupling. Advanced Technology of Electrical Engineering and Energy 30(1):32−35 Google Scholar
[98]	Matsumoto H. 2002. Research on solar power satellites and microwave power transmission in Japan. IEEE Microwave Magazine 3:36−45 doi: 10.1109/MMW.2002.1145674 CrossRef Google Scholar
[99]	Fan X, Mo X, Zhang X. 2015. Research status and application of wireless power transmission technology. Proceedings of the Chinese Society of Electrical Engineering 35:2584−600 doi: 10.13334/j.0258-8013.pcsee.2015.10.026 CrossRef Google Scholar
[100]	Liu C, Shi K, Wang F. 2014. Mass and mass center identification of target satellite after rendezvous and docking. Proceeding of the 11 ^th World Congress on Intelligent Control and Automation, Shenyang, China, 29 June − 4 July, 2014. USA: IEEE. pp. 5802−7. doi: 10.1109/WCICA.2014.7053711
[101]	Tan L, Huang X, Huang H, Zou Y, Li H. 2011. Transfer efficiency optimal control of magnetic resonance coupled system of wireless power transfer based on frequency control. Science China Technological Sciences 54:1428−34 doi: 10.1007/s11431-011-4380-6 CrossRef Google Scholar
[102]	Amjad M, Farooq-i-Azam M, Ni Q, Dong M, Ahmad Ansari E. 2022. Wireless charging systems for electric vehicles. Renewable and Sustainable Energy Reviews 167:112730 doi: 10.1016/j.rser.2022.112730 CrossRef Google Scholar
[103]	Machura P, Li Q. 2019. A critical review on wireless charging for electric vehicles. Renewable and Sustainable Energy Reviews 104:209−34 doi: 10.1016/j.rser.2019.01.027 CrossRef Google Scholar
[104]	Zhou B, Pei J, Calautit JK, Zhang J, Guo F. 2021. Solar self-powered wireless charging pavement—a review on photovoltaic pavement and wireless charging for electric vehicles. Sustainable Energy & Fuels 5:5139−59 doi: 10.1039/d1se00739d CrossRef Google Scholar
[105]	Urano M, Ata K, Takahashi A. 2017. Study on underwater wireless power transfer via electric coupling with a submerged electrode. 2017 IEEE International Meeting for Future of Electron Devices, Kansai (IMFEDK). Kyoto, Japan, 29−30 June, 2017. USA: IEEE. pp. 36−37. doi: 10.1109/IMFEDK.2017.7998030
[106]	Ji L, Zhang C, Ge F, Qian B, Sun H. 2022. A parameter design method for a wireless power transmission system with a uniform magnetic field. Energies 15:8829 doi: 10.3390/en15238829 CrossRef Google Scholar
[107]	Van Mulders J, Delabie D, Lecluyse C, Buyle C, Callebaut G, et al. 2022. Wireless power transfer: systems, circuits, standards, and use cases. Sensors 22:5573 doi: 10.3390/s22155573 CrossRef Google Scholar
[108]	Xia J, Yuan X, Li J, Lu S, Cui X, et al. 2020. Foreign object detection for electric vehicle wireless charging. Electronics 9:805 doi: 10.3390/electronics9050805 CrossRef Google Scholar
[109]	Cai S, Liu Z, Luo X, Shi Z, Xie Y, et al. 2024. Research on metal and living foreign object detection method for electric vehicle wireless charging system. World Electric Vehicle Journal 15:34 doi: 10.3390/wevj15010034 CrossRef Google Scholar
[110]	Deng W, Pei W, Teng Y, Wu Q, Yi Y, et al. 2023. Coordinated control and application of multi-terminal DC distribution system. Energy Reports 9:11−21 doi: 10.1016/j.egyr.2022.12.106 CrossRef Google Scholar
[111]	Martel J, Chang SH, Chevalier G, Ojcius DM, Young JD. 2023. Influence of electromagnetic fields on the circadian rhythm: implications for human health and disease. Biomedical Journal 46:48−59 doi: 10.1016/j.bj.2023.01.003 CrossRef Google Scholar
[112]	Kumazawa A, Diao Y, Hirata A, Hirayama H. 2020. Reduction of human interaction with wireless power transfer system using shielded loop coil. Electronics 9:953 doi: 10.3390/electronics9060953 CrossRef Google Scholar
[113]	Rhee J, Shin Y, Woo S, Lee C, Kim D, et al. 2021. Wireless torque and power transfer using multiple coils with LCC-S topology for implantable medical drug pump. Sensors 21:8150 doi: 10.3390/s21238150 CrossRef Google Scholar
[114]	Özüpak Y. 2024. Analysis and experimental verification of efficiency parameters affecting inductively coupled wireless power transfer systems. Heliyon 10:e27420 doi: 10.1016/j.heliyon.2024.e27420 CrossRef Google Scholar
[115]	Detka K, Górecki K. 2022. Wireless power transfer—a review. Energies 15:7236 doi: 10.3390/en15197236 CrossRef Google Scholar
[116]	Shidujaman M, Samani H, Arif M. 2014. Wireless power transmission trends. 2014 International Conference on Informatics, Electronics & Vision (ICIEV), Dhaka, Bangladesh, 23−24 May, 2014. USA: IEEE. pp. 1−6 . doi: 10.1109/ICIEV.2014.6850770
[117]	Fusco F, Castrillo VU, Giannetta HMR, Albano M, Cavallini E. 2024. Methods, standards and components for wireless communications and power transfer aimed at intra-vehicular applications of launchers. Aerospace 11:132 doi: 10.3390/aerospace11020132 CrossRef Google Scholar

{{lists.name}}

Enhancing wireless charging efficiency: addressing metal interference through advanced electromagnetic analysis and detection techniques

Abstract

Rights and permissions

References

About this article

Cite this article

Article Metrics

Access History

Other Articles By Authors