Abstract
This article presents the design and demonstration of a bidirectional 20-kW wireless charging system (WCS) with a significantly large air gap (11 in) and asymmetrical input-output voltage levels. Analytical and experimental sensitivity analyses of the WCS resonant tank were conducted to verify the optimal operating region under the load and frequency variation. The inverter and rectifier were designed with switching components, the charging pads were designed with double-D (DD) coils, and the tuning networks were designed with an LCC-LCC tuning circuit. The grid and vehicle side tuning circuits were designed separately to achieve a 1:2 gain for the asymmetrical input (800 $\text{V} {\text {dc}}$ ) and output (350 $\text{V} {\text {dc}}$ ) voltages. The proposed WCS was designed, simulated, and tested to verify the efficiency, power transfer capacity, and sensitivity under load variation. The experimental results show that, at 20-kW output power, the achieved grid-to-vehicle DC-DC efficiency was 96.1%, and the vehicle-to-grid DC-DC efficiency was 96.2%. The proposed system is the largest-air gap bidirectional WCS with the highest efficiency and power density.
| Original language | English |
|---|---|
| Article number | 9314237 |
| Pages (from-to) | 1205-1218 |
| Number of pages | 14 |
| Journal | IEEE Transactions on Transportation Electrification |
| Volume | 7 |
| Issue number | 3 |
| DOIs | |
| State | Published - Sep 2021 |
Funding
Manuscript received June 23, 2020; revised August 30, 2020 and October 28, 2020; accepted November 28, 2020. Date of publication January 5, 2021; date of current version August 24, 2021. This paper is authored by the Oak Ridge National Laboratory, operated by UT-Battelle, LLC, through the U.S. Department of Energy, under Contract DE-AC05-00OR22725. (Corresponding author: Omer C. Onar.) The authors are with the Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA (e-mail: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; anwars@ ornl.gov; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]). Digital Object Identifier 10.1109/TTE.2021.3049138 This research used the Power Electronics and Electric Machinery Research Center, National Transportation Research Center, a U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy User Facility operated by the Oak Ridge National Laboratory (ORNL). The authors would like to thank Dr. Burak Ozpineci (ORNL) and Dr. David Smith (ORNL) for their managerial support and technical guidance and Lee Slezak (DOE) and John Jason Conley (National Energy Technology Laboratory) for project guidance. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).
| Funders | Funder number |
|---|---|
| National Transportation Research Center | |
| Office of Energy Efficiency and Renewable Energy User Facility | |
| Power Electronics and Electric Machinery Research Center | |
| U.S. Department of Energy | DE-AC05-00OR22725 |
| Oak Ridge National Laboratory |
Keywords
- Bidirectional wireless charging system (WCS)
- electric vehicle (EV) charging
