EV Wireless Charging Interoperability with TMN Technology

December 05, 2016 by Jeff Shepard

WiTricity announced its Tunable Matching Network (TMN) technology to drive global interoperability and adoption of wireless charging for electric and autonomous vehicles. TMN technology allows the wireless charging system to automatically optimize energy transfer between the ground and vehicle in a wide range of real world operating conditions including parking misalignment, differing vehicle ground clearance and varying battery voltage conditions.

This flexibility enables wirelessly charged vehicles to interoperate more easily with standards-based charging sources made by different automakers, Tier 1 suppliers and infrastructure suppliers. With TMN based systems, drivers can park their wirelessly charged electric vehicles (EVs) and be assured of rapid, efficient and safe charging, without having to handle charging cables or park their vehicle with precision.

The WiTricity TMN technology was recently tested by Idaho National Laboratory (INL), with funding from the U.S. Department of Energy, to support validation of the SAE Technical Information Report (TIR) J2954. SAE TIR J2954 is a guideline for the wireless charging of plug-in electric vehicles that was published by the SAE International (formerly the Society of Automotive Engineers) earlier this year. SAE International, through its J2954 Committee, is at the forefront of defining standards for wireless charging.

WiTricity collaborated with Nissan, the global leader in EV sales, to submit a 7.7kW system with TMN technology for testing as both a stand-alone system and interoperating with systems provided by other suppliers, including WiTricity licensee Toyota. Results of the testing will be used by the J2954 Committee to help establish global standards for wireless charging.

WiTricity’s system – which delivers superior end-to-end efficiency of 91%-94%, as efficient as and often more so than plug-in charging – combines TMN technology with a “circular coil” design that is favored by most automakers due to the design’s high degree of interoperability, intrinsically low emissions, high efficiency and low materials and assembly cost. WiTricity’s TMN technology is delivered as a compact electronics module embodying proprietary hardware and software algorithms, to be incorporated into both the wireless charging source on the ground and the wireless power capture device on the vehicle.

TMN is available as part of WiTricity's DRIVE series of wireless charging systems based on the company's patented magnetic resonance technology. WiTricity’s DRIVE systems, rated at 11 kW, 7.7 kW and 3.7 kW, are provided to carmakers, Tier 1 suppliers and charging infrastructure suppliers as an evaluation and development platform to accelerate development of production units by the carmaker’s supply chain partners.

Automakers around the world are now preparing vehicles for wireless charging, including all-electric and hybrid-electric cars and light trucks. Standardization and interoperability are key catalysts for widespread adoption of wireless charging.

“Delphi is an established licensee and development partner of WiTricity. TMN technology is a real breakthrough in efficiency, interoperability, and cost,” said Randy Sumner, Director, Global Hybrid & Electric Vehicle Business & Technology Development, Delphi Automotive. “This solution will help boost Delphi’s wireless power offerings and those of our customers."

"The electric vehicle market is at an inflection point with global automakers increasing their commitment to EVs," said Alex Gruzen, CEO, WiTricity. "In order to achieve their vision, WiTricity is delivering innovative wireless charging solutions that work seamlessly with different vehicles, surfaces and power levels. We're proud to be enabling the standardization of EV wireless charging technology and enabling a future where any electric car can drive into any parking spot–even autonomously–and automatically charge up."

WiTricity works directly with major automakers and Tier 1 suppliers including Nissan, Toyota, Delphi, TDK, IHI, Prodrive Technologies, BRUSA and others that cannot yet be disclosed due to confidentiality obligations. The company is also involved in the global standards development activities led by SAE International, ISO/IEC, Project STILL-E, The German Commission for Electrical, Electronic & Information Technologies (DKE) and China Automotive Technology and Research Center (CATARC) to promote interoperability of compliant wireless charging systems.