SAE task force agrees on frequency of operation and power classes for wireless power transfer for light-duty plug-in vehicles
SAE International J2954 Task Force for Wireless Power Transfer (WPT) of Light Duty, Electric and Plug-in Electric Vehicles, has agreed upon two key factors for the Technical Information Report (TIR) on interoperability for the first phase of pre-commercial development: a common frequency of operation (85 kHz) and the definition of three power classes for light duty vehicles: WPT 1, 2 and 3.
Made up of OEMs, WPT Suppliers, industry experts and government representatives, the Task Force plans to complete the TIR in early 2014. The SAE Technical Information Report will be followed by publication of SAE J2954 Standard, based on field data confirmation.
A common frequency of operation for WPT is essential for interoperability. After 3 years of international collaboration and investigation within the team, consensus had been reached on a nominal frequency of operation for the light duty vehicle guideline. The SAE team has determined this nominal frequency of 85 kHz for SAE J2954. This frequency lies within an internationally available frequency band. [81.38 - 90.00 kHz].—Jesse Schneider, Chair J2954 Taskforce
The limits for the three power classes are defined by the maximum input Wireless Power Transfer power rating as shown in the table below:
|SAE TIR J2954 WPT Power Classes|
LD Fast Charge
|Maximum Input WPT Power Rating||3.7 kW||7.7kW||22 kW|
The SAE International Task Force is currently working on completing the remaining interoperability topics, including factors such as the minimum coupling factor “k”, alignment, and coil geometries.