EPE Association: EPE 2019 - LS3d: Wireless Power Supply

EPE 2019 - LS3d: Wireless Power Supply
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2019 ECCE Europe - Conference > EPE 2019 - Topic 07: Power Supplies > EPE 2019 - LS3d: Wireless Power Supply

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   Analysis, design and operation strategy of high-efficient Class E2 wireless power transfer systems for automotive EV battery charging applications
By Hannes SCHWAN [View]
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Abstract: A zero current switched Class E2 wireless power transfer battery charging system is proposed for automotive applications and a suitable operating strategy has been developed that always achieves optimum class E operating conditions of the active switching device, independent from transferred power, battery voltage and magnetic coupling. A prototype with two different-size energy transfer coils with 25cm and 60cm outer diameter has been built and tested to verify theoretical predictions obtained from the analyses and the simulations. Efficiencies around 95\% have been achieved at maximum output power and minimum magnetic coupling of k = 0.2. Experimental results are in close correlation with theoretical predictions and show the good performance of the proposed power transfer system.

   Comparison of Misalignment Impact on Multi-Coil Transmitters in Wireless Transfer Systems for Electric Vehicles
By Myrel ALSAYEGH [View]
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Abstract: The misalignment impact on wireless power transfer systems for electric vehicles with a ground assembly comprised of two transmitter coils is analyzed. Different connection configurations, single supply, in which one transmitter is independent resonant to the other, and dual supply, are addressed. Three-dimensional finite element method magnetic field simulations are used.

   Experimental Verification of Impedance Matching Method for Repeater to Improve Spatial Freedom of 6.78 MHz Resonant Inductive Coupling Wireless Power Systems
By Keita FUJIKI [View]
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Abstract: Placing a repeater, which relays the magnetic field from the transmitter to the receiver, is promising as a method to increase the spatial freedom of resonant inductive coupling wireless power transfer systems (RIC-WPT) working at 6.78MHz. However, the capability of the repeater is often affected by a frequency splitting phenomenon. When this phenomenon occurs, the resonance in the repeater becomes sufficiently small at a fixed operating frequency and make it difficult to improve the spatial freedom. To solve this problem, we apply an impedance matching method using simple switching circuits to the 6.78 RIC-WPT system with the repeater. Then we carry out experiments to verify the effectiveness of the impedance matching method. The experimental results show that the repeater improves the spatial freedom of the 6.78 MHz RIC-WPT regardless of the frequency splitting phenomenon.

   Non-uniform Spacing of Ferrite Bars for Optimizing a Solenoid-based Wireless Electric Vehicle Charger with Automatic Self-Alignment
By Nameer KHAN [View]
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Abstract: This paper presents the design of a dual-coil charging pad for Wireless Power Transfer (WPT) in Electric Vehicles (EV). An electro-magnetic coil, denoted as the dc coil, generates a magnetic force that horizontally aligns a linear-slider-mounted transmitter pad to the receiver pad. A solenoid-based coil, denoted as the ac coil, is capable of 5kW WPT, which is performed only after the self-alignment of the pads. Two areas of optimization for the solenoid-based wireless charger are presented: optimum ferrite bar spacing and shield design. By using copper shields composed of a continuous sheet instead of multiple pieces connected with tape, the simulated eddy current loss is reduced by 29\% while minimizing leakage flux from the ac coil. The optimum ferrite bar spacing is verified on a prototype of the dual-coil charging pad and allows the power capability to increase from 3.7 kW to 5 kW, without additional ferrite bars while achieving a peak dc-dc efficiency of 90.1\%. The prototype of the dc coil generates a peak magnetic force of 3.51 N while also achieving a wide horizontal misalignment correction range of up to 240 mm.

EPE 2019 - LS3d: Wireless Power Supply
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2019 ECCE Europe - Conference > EPE 2019 - Topic 07: Power Supplies > EPE 2019 - LS3d: Wireless Power Supply
	[return to parent folder]

	Analysis, design and operation strategy of high-efficient Class E2 wireless power transfer systems for automotive EV battery charging applications By Hannes SCHWAN	[View] [Download]
Abstract: A zero current switched Class E2 wireless power transfer battery charging system is proposed for automotive applications and a suitable operating strategy has been developed that always achieves optimum class E operating conditions of the active switching device, independent from transferred power, battery voltage and magnetic coupling. A prototype with two different-size energy transfer coils with 25cm and 60cm outer diameter has been built and tested to verify theoretical predictions obtained from the analyses and the simulations. Efficiencies around 95\% have been achieved at maximum output power and minimum magnetic coupling of k = 0.2. Experimental results are in close correlation with theoretical predictions and show the good performance of the proposed power transfer system.

	Comparison of Misalignment Impact on Multi-Coil Transmitters in Wireless Transfer Systems for Electric Vehicles By Myrel ALSAYEGH	[View] [Download]
Abstract: The misalignment impact on wireless power transfer systems for electric vehicles with a ground assembly comprised of two transmitter coils is analyzed. Different connection configurations, single supply, in which one transmitter is independent resonant to the other, and dual supply, are addressed. Three-dimensional finite element method magnetic field simulations are used.

	Experimental Verification of Impedance Matching Method for Repeater to Improve Spatial Freedom of 6.78 MHz Resonant Inductive Coupling Wireless Power Systems By Keita FUJIKI	[View] [Download]
Abstract: Placing a repeater, which relays the magnetic field from the transmitter to the receiver, is promising as a method to increase the spatial freedom of resonant inductive coupling wireless power transfer systems (RIC-WPT) working at 6.78MHz. However, the capability of the repeater is often affected by a frequency splitting phenomenon. When this phenomenon occurs, the resonance in the repeater becomes sufficiently small at a fixed operating frequency and make it difficult to improve the spatial freedom. To solve this problem, we apply an impedance matching method using simple switching circuits to the 6.78 RIC-WPT system with the repeater. Then we carry out experiments to verify the effectiveness of the impedance matching method. The experimental results show that the repeater improves the spatial freedom of the 6.78 MHz RIC-WPT regardless of the frequency splitting phenomenon.

	Non-uniform Spacing of Ferrite Bars for Optimizing a Solenoid-based Wireless Electric Vehicle Charger with Automatic Self-Alignment By Nameer KHAN	[View] [Download]
Abstract: This paper presents the design of a dual-coil charging pad for Wireless Power Transfer (WPT) in Electric Vehicles (EV). An electro-magnetic coil, denoted as the dc coil, generates a magnetic force that horizontally aligns a linear-slider-mounted transmitter pad to the receiver pad. A solenoid-based coil, denoted as the ac coil, is capable of 5kW WPT, which is performed only after the self-alignment of the pads. Two areas of optimization for the solenoid-based wireless charger are presented: optimum ferrite bar spacing and shield design. By using copper shields composed of a continuous sheet instead of multiple pieces connected with tape, the simulated eddy current loss is reduced by 29\% while minimizing leakage flux from the ac coil. The optimum ferrite bar spacing is verified on a prototype of the dual-coil charging pad and allows the power capability to increase from 3.7 kW to 5 kW, without additional ferrite bars while achieving a peak dc-dc efficiency of 90.1\%. The prototype of the dc coil generates a peak magnetic force of 3.51 N while also achieving a wide horizontal misalignment correction range of up to 240 mm.