Wireless Charging Key To EV Success

High-power induction charging is a technology that could help speed up adoption and acceptance of EVs.

This statement was said by Momentum Dynamics Corporation’s Founder and CEO Andy Daga who delivered a presentation on high-power wireless charging of electric vehicles at the 2013 Energy Transfer in Electric Vehicle Drive Conference (ETEV) in Nuremberg, Germany.

The ETEV conference focuses on megatrends affecting consumers such as CO2 reduction, power consumption, electromobility and the growth of the electric vehicle marketplace.

Per ETEV, many automotive thought leaders consider electric vehicle charging technology to be a key factor in the growth of the electric vehicle industry and the transition from internal combustion engine-powered vehicles to electric vehicles.

Daga’s comments focused on the status of wireless charging technology versus plug-in charging, and the remaining technical and commercial hurdles that must be overcome.

According to Daga, the most important hurdles are more regulatory and business-related than technical, as the technology has now matured to a point where it can be integrated into production vehicles.

“What is more pressing,” said Daga, “is the need to align this technology with a uniform set of industry standards that will be acceptable to consumers and major vehicle manufacturers.”

In his presentation, Daga outlined two areas of concern, one being a uniform industry interoperability standard that can be operated across all power ranges, and for any type of electric vehicle.

Daga pointed to the more favorable record of performance of inductive charging systems that operate at relatively low frequency, specifically 20 to 30 kilohertz (kHz), as opposed to higher frequencies in the 80 to 100 kHz region of the spectrum.

“Everything in the system, including overall power transfer efficiency, works better at lower frequency and we can eventually extend these lower frequency systems to allow much higher power levels without difficulty,” said Daga. “Related to this is the need to settle on a uniform international standard for human interaction with magnetic fields. In this regard, we strongly favor the existing IEEE C95 standard as the only peer-reviewed international standard that can stand up to rigorous scientific scrutiny.”

At the conference, Daga described the company’s current field trial involving commercial shuttle buses, which are fully electric Ford E-450 production vehicles with wireless automatic charging installed. The chargers operate with automatically adjustable power levels up to 30 kilowatt with 90 percent efficiency.

“In order to succeed commercially, it will require more than power and performance, and we have designed this technology to be price compatible with high-power plug-in systems — hereby making the decision a very simple one for fleet operators,” Daga said while describing the system.

Human safety is known as being an area of concern when it comes to high-power induction charging.

On this issue of human safety, Daga urged companies to get out in front of the issue and point to the science behind the IEEE standard. He pointed out that there are innumerable devices and appliances that are used every day by consumers and industrial workers that employ the technology of resonant magnetic induction in the 20 to 60 KHz portion of the spectrum, and which have been in use for decades.

“There is no documented evidence of any physical harm or injury to people due to commercial magnetic induction devices despite literally billions of interactions since the inception of alternating current electric power,” said Daga. “Perhaps the clearest example happens in commercial and residential kitchens where people routinely use induction cooktops — in these cases the power and magnetic levels are much higher that anyone would experience with an inductive EV charger. But in most circumstances, people experience low-frequency alternating magnetic fields without being aware of it, ranging from household wall current, to anti-theft device scanners in retail stores, to transformers and electric motors, just to name a few.”

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Daga concluded his remarks by pointing out that induction charging of EVs must happen at high power levels to achieve rapid charging, and when commercialized, he expects to see the rapid adoption of EVs due to the advent of automatic opportunity charging.

“We are at a paradigm shift point,” added Daga, “not only will we see high power induction charging as an enabler of the EV industry, but there are many potential commercial applications of this technology that will soon become possible, opening up vast new commercial opportunities in multiple markets.”