EPE Association: EPE 2014 - LS2b: EV's Battery Chargers

EPE 2014 - LS2b: EV's Battery Chargers
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2014 ECCE Europe - Conference > EPE 2014 - Topic 08: e-Mobility > EPE 2014 - LS2b: EV's Battery Chargers

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   Efficiency optimized AC charging waveform for GaN Bidirectional PHEV Battery Charger
By Lingxiao XUE, Paolo MATTAVELLI, Dushan BOROYEVICH, Brian HUGHES, Rolando BURGOS [View]
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Abstract: Sinusoidal charging can boost the power density of GaN-based battery charger with the penalty of dropped efficiency due to hard-switching. In this paper, different AC charging waveforms are investigated to achieve better charger efficiency with slightly increased DC link capacitance. It turns out that PWM-zero-off charging, which shut down DC/DC stage at zero part of the charging current waveform, can greatly reduce converter loss while keeping small DC link voltage ripple. Experiment results from GaN prototype verified the concept and 39\% loss saving is demonstrated.

   Implementation of Sliding-Mode Observer combined with Aging Compensation for Improved SOC Estimation
By Kim JONGHOON [View]
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Abstract: This work gives insight to the design and implementation of an improved state-of-charge (SOC) estimation using sliding-mode observer (SMO) combined with aging compensation via recursive least squares (RLS) for a degraded Li-Ion cell. The main advantage of this approach would be low computational load and easiness of implementation along with the robustness of the method for internal battery model parameters used for SOC estimation. This work used as a part of either a Matlab/Simulink model or an integral part of the battery management system (BMS)-micro controller unit (MCU) of STM32F105VC, was verified by the comparison with experimental data of 1.5Ah LiCoO2 degraded cell produced by Samsung SDI.

   Reduction of Magnetic Emission by Increasing Secondary Side Capacitor for Ferrite Geometry based Series-Series Topology for Wireless Power Transfer to Vehicles
By Tushar BATRA, Erik SCHALTZ, Seungyoung AHN [View]
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Abstract: Magnetic fields emitted by wireless power transfer to vehicles can potentially affect living organisms. As a result, minimizing the magnetic emissions without compromising with the power transferred is one of the most significant challenges in the success of this technology. Active and passive shielding methods are used for screening of the magnetic fields of this system. In this paper, a new active shielding design method for series-series topology of this technology has been presented. In this method, the secondary capacitor value is increased to reduce phase angle between the primary and secondary currents from the standard design. Therefore, a part of the secondary magnetic flux comes in phase opposition with the primary flux and the resultant field is reduced. Operation point is shifted with the new design from the maximum power transfer resonance point and hence the reflected resistance is reduced. In order to maintain the same power level, the primary current and voltage have to increased and decreased in the same proportion. Also, the primary capacitor needs to be increased for maintaining unity input power factor in the system. The above statements are provided first with help of analytical expressions and later substantiated with simulations. At the end, it is also shown that resonance in the system is still intact with this new design methodology.

   Wireless Charging for vehicles - Some Key Elements
By Mikael ALATALO, Sonja LUNDMARK, Eva PALMBERG, Torbjörn THIRINGER, Robert KARLSSON [View]
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Abstract: In this paper so called wireless charging is investigated, primarily considering applications such as charging hybrid or electric vehicles at stand-still. The base concept investigated is a sending and a receiving coil at various designs. The theory behind wireless energy transfer and the needed components are described and analyzed, showing how design aspects, frequencies, height and vertical displacement affect the results. Analytical expressions, measurements, as well as FEM analyses in 2D and 3D with two different FEM programs have been compared, with a reasonable agreement between methods.

EPE 2014 - LS2b: EV's Battery Chargers
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2014 ECCE Europe - Conference > EPE 2014 - Topic 08: e-Mobility > EPE 2014 - LS2b: EV's Battery Chargers
	[return to parent folder]

	Efficiency optimized AC charging waveform for GaN Bidirectional PHEV Battery Charger By Lingxiao XUE, Paolo MATTAVELLI, Dushan BOROYEVICH, Brian HUGHES, Rolando BURGOS	[View] [Download]
Abstract: Sinusoidal charging can boost the power density of GaN-based battery charger with the penalty of dropped efficiency due to hard-switching. In this paper, different AC charging waveforms are investigated to achieve better charger efficiency with slightly increased DC link capacitance. It turns out that PWM-zero-off charging, which shut down DC/DC stage at zero part of the charging current waveform, can greatly reduce converter loss while keeping small DC link voltage ripple. Experiment results from GaN prototype verified the concept and 39\% loss saving is demonstrated.

	Implementation of Sliding-Mode Observer combined with Aging Compensation for Improved SOC Estimation By Kim JONGHOON	[View] [Download]
Abstract: This work gives insight to the design and implementation of an improved state-of-charge (SOC) estimation using sliding-mode observer (SMO) combined with aging compensation via recursive least squares (RLS) for a degraded Li-Ion cell. The main advantage of this approach would be low computational load and easiness of implementation along with the robustness of the method for internal battery model parameters used for SOC estimation. This work used as a part of either a Matlab/Simulink model or an integral part of the battery management system (BMS)-micro controller unit (MCU) of STM32F105VC, was verified by the comparison with experimental data of 1.5Ah LiCoO2 degraded cell produced by Samsung SDI.

	Reduction of Magnetic Emission by Increasing Secondary Side Capacitor for Ferrite Geometry based Series-Series Topology for Wireless Power Transfer to Vehicles By Tushar BATRA, Erik SCHALTZ, Seungyoung AHN	[View] [Download]
Abstract: Magnetic fields emitted by wireless power transfer to vehicles can potentially affect living organisms. As a result, minimizing the magnetic emissions without compromising with the power transferred is one of the most significant challenges in the success of this technology. Active and passive shielding methods are used for screening of the magnetic fields of this system. In this paper, a new active shielding design method for series-series topology of this technology has been presented. In this method, the secondary capacitor value is increased to reduce phase angle between the primary and secondary currents from the standard design. Therefore, a part of the secondary magnetic flux comes in phase opposition with the primary flux and the resultant field is reduced. Operation point is shifted with the new design from the maximum power transfer resonance point and hence the reflected resistance is reduced. In order to maintain the same power level, the primary current and voltage have to increased and decreased in the same proportion. Also, the primary capacitor needs to be increased for maintaining unity input power factor in the system. The above statements are provided first with help of analytical expressions and later substantiated with simulations. At the end, it is also shown that resonance in the system is still intact with this new design methodology.

	Wireless Charging for vehicles - Some Key Elements By Mikael ALATALO, Sonja LUNDMARK, Eva PALMBERG, Torbjörn THIRINGER, Robert KARLSSON	[View] [Download]
Abstract: In this paper so called wireless charging is investigated, primarily considering applications such as charging hybrid or electric vehicles at stand-still. The base concept investigated is a sending and a receiving coil at various designs. The theory behind wireless energy transfer and the needed components are described and analyzed, showing how design aspects, frequencies, height and vertical displacement affect the results. Analytical expressions, measurements, as well as FEM analyses in 2D and 3D with two different FEM programs have been compared, with a reasonable agreement between methods.