Despite advancements in wireless devices, consumers still rely on cords, cables and replaceable batteries to fuel them. Recent advancements in wireless power show promise of eliminating cords altogether, but one article published in IEEE Transactions on Industrial Electronics shows promise of making this technology a quicker reality for every-day consumers.
Wireless power is becoming increasingly popular due to its high energy transfer efficiency, short charging time and ease of use. But power shortages are common when transferring over longer distances. Therefore, researchers hope to overcome this challenge by proposing a “natural power localization mechanism” using multicoil inductive links (Fig. 1), a relatively new technology discovered in 2004. Multicoil inductive links are known for optimizing power efficiency and providing better wireless transmission. Recently, three-coil and four-coil links have demonstrated higher power transmission efficiency over longer distances.
Figure 1: Representation of a conventional multicoil inductive link.
With this in mind, the researchers propose a power transmission prototype that uses multicoil links in a parallel array structure (Fig. 2). The new design is based on a four-coil link, but its primary resonator uses a coil array made of several resonators connected next to each other in parallel. This parallel formation helps prevent power loss from occurring, by naturally localizing the transmitted power towards the receiver location.
Figure 2: Proposed inductive array principle.
Another benefit is that the prototype can operate with both short and long-range applications. Short range applications typically use a three-coil configuration to transfer power; for example, wirelessly charging smart phones. Long-range applications, like monitoring systems in animal research, use a four-coil configuration due to the longer distance over which power needs to wirelessly transfer. The new prototype can switch between both transmission ranges simply by changing the receiver topology. Adding or removing the secondary resonator switches the prototype between three or four-coil topologies so that it supplies the right amount of power.
“We’re very excited about this prototype because it can be used to wireless charge many different applications,” said Abdollah Mirbozorgi, Lead Researcher at the Université Laval in Quebec, Canada. “Its expanded capabilities allow it to more conveniently power smart phones and tablets, but also more unique applications like computer mouses, smart animal research systems, electric cars and even implantable medical devices.”
This prototype is already being used by various wireless transmission companies, suggesting that lift-off to an entirely wireless world may not be so far away.