{"id":1610,"date":"2011-09-01T20:04:08","date_gmt":"2011-09-01T20:04:08","guid":{"rendered":"http:\/\/www.joswassink.nl\/insight\/?p=1610"},"modified":"2011-09-01T20:04:08","modified_gmt":"2011-09-01T20:04:08","slug":"charging-down-electric-avenue","status":"publish","type":"post","link":"https:\/\/www.joswassink.nl\/insight\/?p=1610","title":{"rendered":"Charging down Electric Avenue"},"content":{"rendered":"<div id=\"attachment_1611\" style=\"width: 310px\" class=\"wp-caption alignright\"><a rel=\"attachment wp-att-1611\" href=\"http:\/\/www.joswassink.nl\/insight\/?attachment_id=1611\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-1611\" class=\"size-thumbnail wp-image-1611\" title=\"scienceaccu_dsc3876bew_548x365\" src=\"http:\/\/www.joswassink.nl\/insight\/wp-content\/uploads\/scienceaccu_dsc3876bew_548x365-300x199.jpg\" alt=\"\" width=\"300\" height=\"199\" \/><\/a><p id=\"caption-attachment-1611\" class=\"wp-caption-text\">Swagat Chopra demonstrates - Photo: Tomas van Dijk<\/p><\/div>\n<p><strong>Range anxiety holds people back from buying electric vehicles. But what if the road itself would keep the batteries charged?<\/strong><\/p>\n<p>In the laboratory, MSc student\u00a0Swagat Chopra places his model car  above a square coil of electric wire. The car carries a similar but  smaller coil below its chassis. Chopra flicks some switches and the  voltage over the car\u2019s batteries starts rising. This is magic: power  transfer through the air.<!--more--><\/p>\n<p>The physics is not so different from what happens in any transformer, says<br \/>\nChopra\u2019s  supervisor, Professor Pavol Bauer (Electrical Engineering, Mathematics  and Computer Science). The only difference is that the primary and  secondary coils are not linked by a chunk of iron, but rather by a gap  of air. To overcome this obstacle, high frequencies are used (typically  100 kilohertz) and the coils are tuned to the same resonance frequency.<\/p>\n<p>Contactless Power Transfer (CPT) has many advantages over socket  charging, Prof. Bauer explains. Not only is the technology more  convenient and safer, CPT also offers the opportunity of charging  vehicles wait for the traffic lights by means of embedded coils in the  street. Equip motorways with such power antennas and cars could be  charged while driving down \u2018Electric Avenue\u2019.<\/p>\n<p>What\u2019s more: it would be better for the batteries as well. The Li-ion  battery model that MSc student Long Lam developed shows that short  charging and discharging cycles prolong battery life. Lam\u2019s model for  Li-ions batteries reveals that it would be better to recharge the  batteries at every traffic light than to fast-charge it to the brim and  drive home without recharging. Clearly, CPT offers the opportunity to  provide specially adapted vehicles with easy small recharges.<\/p>\n<p>So what\u2019s holding back the introduction? Apart from the obviously  large investments needed to electrify the roads, there are also doubts  as to the system\u2019s efficiency. Although the energy transfer between the  coils reached 91 percent efficiency, the overall efficiency got stuck at  83.2 percent, due to losses in the power electronics, which transfer  direct currents to high frequency AC and back. Prof. Bauer\u2019s group  however is determined to improve the CPT\u2019s overall efficiency.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Swagat Chopra developed contactless power transfer for electric vehicles<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,6],"tags":[108,148,344,427],"class_list":["post-1610","post","type-post","status-publish","format-standard","hentry","category-articles","category-delta","tag-cpt","tag-electric-cars","tag-power-transmission","tag-swagat-chopra"],"_links":{"self":[{"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=\/wp\/v2\/posts\/1610","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1610"}],"version-history":[{"count":0,"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=\/wp\/v2\/posts\/1610\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1610"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1610"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.joswassink.nl\/insight\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1610"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}