Frequency Optimization of a Loosely Coupled Underwater Wireless Power Transfer System Considering Eddy Current Loss

Zhang, Yan; Zhang, Yiming; Kan, Tetsuo; Lu, Fei; Zhang, Kehan; Song, Baowei; Mi, Chris

doi:10.1109/tie.2018.2851947

Cited by 146 publications

(45 citation statements)

References 21 publications

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“…In Figure 5, human or the electronics may be exposed in Area I, so we choose the stray EMF in Area I as the analysis target. From paper [14,15], we can get that the electric field excited by a single-turn circular coil can be calculated with Equation (43) and the method is proven by researchers. From Figure 3, it is very clear that Meq doesn't change with the turn of shielding coils and MPS decreases first and then increase with the increases of the turn of shielding coils.…”

Section: Electric Field Analysismentioning

confidence: 99%

Analysis and Experiment for Wireless Power Transfer Systems with Two Kinds Shielding Coils in EVs

2020

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Electric vehicles (EVs) with wireless power transfer (WPT) systems are convenient, but WPT technology will produce a strong stray electromagnetic field (EMF) in the surrounding space when the system works with high power. Shielding coils can reduce stray EMF efficiently without additional control, and they have advantages of being simple, light, and cheap. In this paper, the series-opposing structure is compared systematically with the inductive structure based on circuit theory and electromagnetic field theory. Simplified circuit models are proposed to give an intuitive and comprehensive analysis of transfer efficiency. Electric field analysis and finite element analysis (FEA) is used to explain the functional principles of shielding coils and to compare the EMF distribution excited by two structures. The simulation results show that both structures decrease the mutual inductance and perform better than the system without shielding coils when they have the same transfer efficiency. Further, the inductive structure system performs best. The most important between two structures is that the shielding effects is independent of turns of shielding coils for inductive structure, while it can be adjusted by changing turns of shielding coils for the series-opposing structure. The experimental results show that the EMF is reduced by 65% for the inductive structure and 40% for the series-opposing structure. The theoretical analysis is confirmed by experimental results.

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Section: Electric Field Analysismentioning

confidence: 99%

Analysis and Experiment for Wireless Power Transfer Systems with Two Kinds Shielding Coils in EVs

2020

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“…Comparing to the air whose conductivity is approximately zero, fresh water has a conductivity of 0.1 S/m while sea water has an even higher conductivity of around 4 S/m. Thus, extra eddy current loss in the seawater would reduce the system efficiency [18]. Though with excellent heat conduction capa-bility, the temperature rise will not destroy the components or the coils, a high efficiency is hard to achieve especially with a large transmission distance.…”

Section: Fig 1 Fundamental Operation With Two-coil Wpt Systemmentioning

confidence: 99%

Investigation and Design of Wireless Power Transfer System for Autonomous Underwater Vehicle

Dou

Zhao

Ouyang

et al. 2019

2019 IEEE Applied Power Electronics Conference and Exposition (APEC)

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With the development of wireless power transfer (WPT) technology, it is possible to transfer power to the batteries without plug-in cables and human interaction for autonomous underwater vehicles (AUVs), taking advantage of high safety, high reliability and unattended capability. However, when implementing the WPT system under the seawater environment, the electrical properties of seawater including the permittivity and the conductivity cause a significant changing in the parasitics of winding coils underwater. The seawater, which owns higher permittivity and conductivity compared to the air, not only causes extra parasitic capacitance to coils but also conducts extra eddy current loss, and thus reduces the system efficiency. In this paper, the characteristics of winding coils underwater are investigated and an optimized design methodology for underwater WPT system with series-series (SS) compensation is proposed. A 200-W underwater WPT prototype is built and experimentally verifies the analysis for the coils and the optimized design approach. The experimental demonstration also shows the system efficiency comparison between the air, the water, and the seawater environments.

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“…eccentricity resistance and it is able to transfer 1.0 kW with the efficiency of 92.41%. In paper [12], researchers analyzed the eddy current loss (ECL) in an underwater WPT system and obtained the optimization frequency while considering ECL. A1 × 1 × 1 structure was proposed to reduce ECL of underwater WPT system, and the AC-AC power transfer efficiency was improved by nearly 10% when compared to the conventional structure in paper [13].…”

Section: Introductionmentioning

confidence: 99%

Application of Shielding Coils in Underwater Wireless Power Transfer Systems

Wang

Song

Mao

2019

JMSE

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Underwater wireless power transfer (WPT) technology can enhance the endurance of the autonomous underwater vehicles (AUV). WPT that based on electromagnetic theory will generate eddy current loss (ECL) in seawater. In this paper, we make use of shielding coils to weaken the electromagnetic field (EMF) in seawater, which can reduce ECL and improve the transfer efficiency. Simplified circuit models were proposed to provide an intuitive and comprehensive analysis of the transfer efficiency and the finite element analysis (FEA) was used to simulate the distribution of EMF. We learn that the system with shielding coils performs better when the operating frequency is relatively high by comparing the power transfer efficiency of the underwater WPT systems with and without the shielding, and its maximum efficiency is higher than the system without shielding. The effect of the shielding coils has the similar influence when compared with the metallic plate. While considering the efficiency and weight of coils, the results show that the shielding coils can be used in the underwater WPT system to improve the power transfer efficiency.

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Frequency Optimization of a Loosely Coupled Underwater Wireless Power Transfer System Considering Eddy Current Loss

Cited by 146 publications

References 21 publications

Analysis and Experiment for Wireless Power Transfer Systems with Two Kinds Shielding Coils in EVs

Analysis and Experiment for Wireless Power Transfer Systems with Two Kinds Shielding Coils in EVs

Investigation and Design of Wireless Power Transfer System for Autonomous Underwater Vehicle

Application of Shielding Coils in Underwater Wireless Power Transfer Systems

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