UNIST(총장 박종래) 전기전자공학과 변영재 교수팀이 3차원 공간 어디에서든 충전이 가능한 전기공진 방식의 무선전력전송(ERWPT) 기술을 세계 최초로 개발하며, 벽, 바닥, 공중 등 3차원 공간 안에서 어디서든 충전이 가능해 향후 가정에서 뿐만 아니라 스마트로봇 등 산업에서도 다양하게 사용될 것으로 기대가 모아진다.
UNIST, Implementation of Wireless Power Transmission Technology Using Electric Resonance
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The era of charging your phone while it's in your pocket is approaching. This is because technology has been developed that allows wireless charging of electronic devices anywhere in three-dimensional space, including on walls, floors, and in the air.
UNIST (President Jong-Rae Park) announced on the 12th that Professor Young-Jae Byun's research team in the Department of Electrical and Electronic Engineering developed the world's first electric resonance wireless power transfer (ERWPT) technology that enables charging anywhere in three-dimensional space.
The research team developed a wireless power transmission technology using electric resonance, taking inspiration from the characteristic of electric fields maintaining a certain directionality.
This is a technology that overcomes the limitations of the existing magnetic resonance method, which could only be charged when placed in a specific location, even with wireless charging.
In the magnetic resonance method, the charging efficiency drops sharply if the transmitter and receiver positions are slightly off because the magnetic field tends to return to its original position.
The developed technology demonstrated a wireless power transfer efficiency of 46% within a space of up to 2 m in length, width, and height. In 2007, researchers at MIT in the United States achieved a transmission efficiency of 40% at a distance of up to 2 m using the 'magnetic resonance method'.
Professor Byun Young-jae explained, “If the MIT research team demonstrated the possibility of mid-range charging using magnetic resonance, this technology is an innovation that evolves from that and enables charging anywhere in three-dimensional space.” He added, “It will be able to provide wireless charging solutions for logistics robots and automation systems in smart factories.”
The research team improved the physical structure of the transmitter and receiver so that the receiver can be freely charged in an electric field, and implemented this power transfer method by applying an 'open bifilar coil' structure. By replacing the traditional coil structure with an open bifilar coil structure, the electric resonance is optimized, enabling wireless power transfer even at long distances.
This charging method can also charge multiple electronic devices simultaneously. Experiments have shown that power can be transmitted with the same efficiency even when multiple receivers are placed in the same space.
The research team also explained that this study has academic value beyond technical achievements in that it presents a new approach to the nature of electromagnetic force.
“The ERWPT system goes beyond technological achievements by suggesting a new energy transfer method using electromagnetic force and shows a new approach to the nature of electromagnetic force,” said Dr. Lee Bon-young, the first author of the study and a UNIST researcher.
This study was co-authored by SB Solution Research Center Director Min Hyeong-gi.
The research results were published online on November 21 in the international academic journal Advanced Science, and the research was conducted with the support of the Ministry of Science and ICT's Institute of Information and Communications Technology Planning and Evaluation (IITP).

▲Developed mid-range ERWPT system
A) Structure of ERWPT system that achieved mid-distance power transmission distance by implementing Open Bifilar Coil in power receiver B) Mid-distance ERWPT experimental measurement environment (2m power transmission distance)