Back to all articles

26 Sep 2022 • 2 min read

Metergram Insights: Wireless Charging In Electric Vehicles Continues To Be A Popular Research Topic

featured image

As charging continues to be a primary concern for many electric vehicle owners, continued research is being done on convenient and widely available solutions. Conductive chargers remain the standard for doing so, but some researchers are also looking into the viability of alternatives. Although still unproven in the field of electric vehicles, the popularity of wireless power transfer chargers in other areas makes it a popular research topic.

Recent research has indicated that wireless charging could be a safer solution for EV owners. This is due to the lack of any heavy cables that need to be handled by users. Research has also shown that going wireless would eliminate certain risks, such as electric shocks during snowy or rainy conditions. Another advantage that would make wireless charging preferable is the absence of physical contact that could cause mechanical friction. In the long run, this would mean less maintenance and a longer lifetime for the wireless charger. 

Some of the proposed solutions for wireless charging feature a concept involving two subsystems. One is a ground assembly that would feature an embedded emitting coil, while the other is the vehicle assembly installed underneath the vehicle. Power would then be transferred wirelessly between these two subsystems via magnetic fields. Wireless charging would have less risk of cables being stolen or damaged and decreases the likelihood of accidents such as cars running over cables.

While looking at the viability of wireless chargers, researchers have also looked into new types of power converters for minimizing power switching losses. Popular frontrunners in this area are emerging technologies, such as Silicon Carbide MOSFET and Gallium Nitride High Electron Mobility Transistors (https://www.richardsonrfpd.com/docs/rfpd/Microsemi-A-Comparison-of-Gallium-Nitride-Versus-Silicon-Carbide.pdf).

After simulating tests using Ansys/Maxwell software, promising results were obtained. In optimal working scenarios, the charger was able to ensure good efficiency of around 90%, while the efficiency in worst-case scenarios only dropped to 83% (https://www.mdpi.com/2032-6653/13/7/121/htm). However, the latter is still above the SAJ2954 limit, which is the standard for wireless power transfer for electric vehicles. 

Wireless charging for vehicles continues to be a concept that draws a lot of research, but existing proposals have proved to be both costly and challenging to implement as well as slower than charging via a cable.. A lot of research has also gone into the possibility of charging vehicles in motion by manufacturers such as Toyota. However, the dream of unlimited range BEVs continues to be held back by technical limitations such as device strength, power loss, and magnetic flux (https://www.toyota-global.com/innovation/partner_robot/news/202112_01.html). 

One thing that is certain is that EVs are here to stay, and research into ways to make charging faster, safer, and more convenient will be ongoing.

Featured Articles