• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.186-188
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• 2018

In this paper, a single-phase multifunctional onboard battery charger with small DC-link capacitors is proposed, where the low-voltage battery charger is utilized as an active power filter to mitigate the inherent second-order ripple power when the high-voltage (HV) battery is charged from the grid. In this scheme, the large DC-link electrolytic capacitors of the HV battery charger can be eliminated without additional switches, leading to the reduction of cost and volume of the onboard battery charger. The validity of the proposed topology has been verified by the simulation results.

• Journal of Power Electronics
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• v.19 no.2
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• pp.394-402
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• 2019

This paper proposes a single-phase non-isolated onboard battery charger (OBC) for electric vehicles (EVs) that only uses small film capacitors at the DC-link of the AC-DC converter. In the proposed charger, an isolated DC-DC converter for low-voltage batteries is used as an active power decoupling (APD) circuit to absorb the ripple power when a high-voltage (HV) battery is charged. As a result, the DC-link capacitance in the AC-DC converter of the HV charging circuit can be significantly reduced without requiring any additional devices. In addition, some of the components of the proposed circuit are shared in common for the different operating modes among the AC-DC converter, LV charging circuit and active power filter. Therefore, the cost and volume of the onboard battery charger can be reduced. The effectiveness of the proposed topology has been verified by the simulation and experimental results.

• Journal of Power Electronics
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• v.17 no.1
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• pp.11-19
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• 2017

This paper proposes a dc/dc converter for electric vehicle onboard chargers using a secondary resonant tank. To attain soft switching characteristics, such as zero voltage switching, magnetizing inductance has been used at the primary side of the transformer. The leakage inductance of the transformer is used as a resonant inductor on the secondary side to avoid the use of a separate inductor as resonance. The proposed converter is applicable for a wide load range. A 6.6KW prototype has been implemented for a wide range of load variations (250V, 330V, 360V, and 413V). A maximum efficiency of 97.4% is achieved at 413V.