Chinese and British researchers have developed a wireless charging system for new energy vehicles (NEVs) that achieves a power conversion efficiency of more than 98 percent.
The system could help support the wider use of autonomous vehicles and may also be used in areas including rail transport, industrial robots and low-altitude aircraft.
A fully automated charging system that does not require human intervention is considered important for the commercial development of autonomous vehicles. Inductive power transfer, which uses magnetic fields to transfer electricity, is widely seen as a suitable technology for such charging.
However, conventional systems using ferrite cores face challenges in achieving high efficiency and power density while maintaining thermal stability. Improving these factors has remained a major challenge for wireless charging technology.
Researchers from the Dongguan Institute of Materials Science and Technology in Guangdong Province, under the Chinese Academy of Sciences (CAS), worked with the City University of Hong Kong, the University of Cambridge and the CAS Institute of Physics to develop a 20-kW-class wireless charging system.
Using nanocrystalline alloys, the system achieved a conversion efficiency of 98.51 percent, according to the researchers.
Their findings, recently published in Nature Communications, describe a magnetic core structure designed in a shape similar to an overpass. The structure can withstand the high temperatures associated with long-term wireless charging.
The magnetic core strip developed by the team is 440 mm long, 330 mm wide and 4 mm thick. It is about half as thick as conventional ferrite-based solutions while supporting a higher power density.
Researchers said the system could be further improved to increase charging efficiency. The Dongguan institute is also working to advance its industrial application.
The technology could be used not only for autonomous vehicles but also in rail transit, automated guided vehicles used in factories and low-altitude aircraft, according to the institute.
In September, China’s Ministry of Industry and Information Technology and eight other government departments issued a five-year plan for the intelligent connected NEV industry covering 2026 to 2030.
The plan aims for autonomous-driving vehicles to achieve large-scale application in China by 2030, including highly automated driving on highways, urban expressways and some urban roads.