The SAE task force working on a standard for Wireless Power Transfer (WPT) has reached agreement on two important factors. These will be incorporated into a Technical Information Report, which is scheduled to be complete in early 2014. The TIR will be followed by publication of the official SAE J2954 Standard.

“A common frequency of operation for WPT is essential for interoperability,” said  Task Force Chair Jesse Schneider. “After 3 years of international collaboration and investigation within the team, consensus had been reached on a nominal frequency of operation of 85 kHz for the light duty vehicle guideline. This frequency lies within an internationally available frequency band.”

The SAE team has also determined three power classes for light duty vehicles: WPT 1, 2 and 3. These limits are defined by the maximum input Wireless Power Transfer power rating, as follows:

• WPT1 – 3.7 kW
• WPT2 (Private/Public Parking) – 7.7 kW
• WPT3 (Light Duty Fast Charge) – 22 kW

The task force is currently working on completing the remaining interoperability topics, including factors such as the minimum coupling factor “K,” alignment, and coil geometries.

Image: Plugless Power
Source: SAE