{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,5]],"date-time":"2025-11-05T21:11:06Z","timestamp":1762377066951,"version":"build-2065373602"},"reference-count":21,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2021,12,9]],"date-time":"2021-12-09T00:00:00Z","timestamp":1639008000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Capacitive power transfer (CPT) has attracted attention for on-road electric vehicles, autonomous underwater vehicles, and electric ships charging applications. High power transfer capability and high efficiency are the main requirements of a CPT system. This paper proposes three possible solutions to achieve maximum efficiency, maximum power, or conjugate-matching. Each solution expresses the available load power and the efficiency of the CPT system as functions of capacitive coupling parameters and derives the required admittance of the load and the source. The experimental results demonstrated that the available power and the efficiency decrease by the increasing of the frequency from 300 kHz to 1 MHz and the separation distance change from 100 to 300 mm. The maximum efficiency solution gives 83% at 300 kHz and a distance of 100 mm, while the maximum power solution gives the maximum normalized power of 0.994 at the same frequency and distance. The CPT system can provide a good solution to charge electric ships and underwater vehicles over a wide separation distance and low-frequency ranges.<\/jats:p>","DOI":"10.3390\/s21248233","type":"journal-article","created":{"date-parts":[[2021,12,9]],"date-time":"2021-12-09T21:46:58Z","timestamp":1639086418000},"page":"8233","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Optimal Solutions for Underwater Capacitive Power Transfer"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8161-5354","authenticated-orcid":false,"given":"Hussein","family":"Mahdi","sequence":"first","affiliation":[{"name":"Department of Electrical Engineering, UiT\u2014The Arctic University of Norway, 8514 Narvik, Norway"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7328-3505","authenticated-orcid":false,"given":"Bjarte","family":"Hoff","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, UiT\u2014The Arctic University of Norway, 8514 Narvik, Norway"}]},{"given":"Trond","family":"\u00d8strem","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, UiT\u2014The Arctic University of Norway, 8514 Narvik, Norway"}]}],"member":"1968","published-online":{"date-parts":[[2021,12,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"38","DOI":"10.1109\/TTE.2017.2771619","article-title":"A Comprehensive Review of Wireless Charging Technologies for Electric Vehicles","volume":"4","author":"Ahmad","year":"2018","journal-title":"IEEE Trans. Transp. Electrif."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1109\/JESTPE.2013.2264473","article-title":"Modern Trends in Inductive Power Transfer for Transportation Applications","volume":"1","author":"Covic","year":"2013","journal-title":"IEEE J. Emerg. Sel. Top. Power Electron."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Lu, F., Zhang, H., and Mi, C. (2017). A Review on the Recent Development of Capacitive Wireless Power Transfer Technology. Energies, 10.","DOI":"10.3390\/en10111752"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1132","DOI":"10.1109\/TPEL.2021.3098848","article-title":"Common Mode Noise Analysis for Inductive Power Transfer System Based on Distributed Stray Capacitance Model","volume":"37","author":"Mei","year":"2021","journal-title":"IEEE Trans. Power Electron."},{"key":"ref_5","first-page":"8541","article-title":"A Four-Plate Compact Capacitive Coupler Design and LCL-Compensated Topology for Capacitive Power Transfer in Electric Vehicle Charging Application","volume":"31","author":"Zhang","year":"2016","journal-title":"IEEE Trans. Power Electron."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"964","DOI":"10.1109\/TPEL.2017.2735365","article-title":"A Two-Plate Capacitive Wireless Power Transfer System for Electric Vehicle Charging Applications","volume":"33","author":"Lu","year":"2018","journal-title":"IEEE Trans. Power Electron."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1633","DOI":"10.1109\/TPEL.2017.2674688","article-title":"A Double-Sided LC-Compensation Circuit for Loosely Coupled Capacitive Power Transfer","volume":"33","author":"Lu","year":"2018","journal-title":"IEEE Trans. Power Electron."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Urano, M., Ata, K., and Takahashi, A. (2017, January 29\u201330). Study on underwater wireless power transfer via electric coupling with a submerged electrode. Proceedings of the IMFEDK 2017\u20142017 International Meeting for Future of Electron Devices, Kansai, Kyoto, Japan.","DOI":"10.1109\/IMFEDK.2017.7998030"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"5873","DOI":"10.1109\/TMTT.2018.2875960","article-title":"Design of a Capacitive Wireless Power Transfer System for Operation in Fresh Water","volume":"66","author":"Tamura","year":"2018","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"759","DOI":"10.1587\/transele.E101.C.759","article-title":"Design of capacitive coupler in underwater wireless power transfer focusing on kQ product","volume":"E101C","author":"Tamura","year":"2018","journal-title":"IEICE Trans. Electron."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1161","DOI":"10.1109\/TMTT.2020.3041245","article-title":"Design of Conductive Coupler for Underwater Wireless Power and Data Transfer","volume":"69","author":"Tamura","year":"2021","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"5191","DOI":"10.1109\/TII.2019.2948649","article-title":"Insulated Coupler Structure Design for the Long-Distance Freshwater Capacitive Power Transfer","volume":"16","author":"Zhang","year":"2020","journal-title":"IEEE Trans. Ind. Inform."},{"key":"ref_13","first-page":"1605","article-title":"Evaluation of Capacitive Power Transfer for Small Vessels Charging Applications","volume":"2020","author":"Mahdi","year":"2020","journal-title":"IEEE Int. Symp. Ind. Electron."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Mahdi, H., Hoff, B., and \u00d8strem, T. (2021, January 1\u20134). Maximum Available Power of Undersea Capacitive Coupling in a Wireless Power Transfer System. Proceedings of the 2021 IEEE Wireless Power Transfer Conference (WPTC), San Diego, CA, USA.","DOI":"10.1109\/WPTC51349.2021.9458006"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Lecluyse, C., Minnaert, B., and Kleemann, M. (2021). A Review of the Current State of Technology of Capacitive Wireless Power Transfer. Energies, 14.","DOI":"10.3390\/en14185862"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"20140147","DOI":"10.1587\/elex.11.20140147","article-title":"Extended k-Q product formulas for capacitive- and inductive-coupling wireless power transfer schemes","volume":"11","author":"Ohira","year":"2014","journal-title":"IEICE Electron. Express"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"e2187","DOI":"10.1002\/jnm.2187","article-title":"Modelling of wireless power transfer links based on capacitive coupling","volume":"30","author":"Dionigi","year":"2017","journal-title":"Int. J. Numer. Model. Electron. Netw. Devices Fields"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"198p","DOI":"10.1109\/JRPROC.1946.234242","article-title":"Conjugate-Image Impedances","volume":"34","author":"Roberts","year":"1946","journal-title":"Proc. IRE"},{"key":"ref_19","unstructured":"Sverdrup, K.A., Duxbury, A.B., and Duxbury, A. (2005). An Introduction to the World\u2019s Oceans, McGraw-Hill Higher Education."},{"key":"ref_20","unstructured":"Griffiths, D. (2008). Introduction to Electrodynamics, Pearson. [3rd ed.]."},{"key":"ref_21","unstructured":"Jackson, J. (1999). Classical Electrodynamics, John Wiley & Sons. [3rd ed.]."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/24\/8233\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:44:09Z","timestamp":1760168649000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/24\/8233"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,12,9]]},"references-count":21,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2021,12]]}},"alternative-id":["s21248233"],"URL":"https:\/\/doi.org\/10.3390\/s21248233","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2021,12,9]]}}}