Wireless Power Transfer for Heavy-Duty Electric Vehicles
The published SAE J2954 standard established an industry-wide specification that defines acceptable criteria for interoperability, electromagnetic compatibility, EMF, minimum performance, safety, and testing for wireless power transfer (WPT) for light-duty plug-in electric vehicles. This SAE Information Report, SAE J2954/2, defines new power transfer levels in the higher power ranges needed for heavy-duty electric vehicles. This document addresses the requirements based on these charge levels and different vehicle applications as a first step in the process of completing a standard that the industry can use, both for private (fleet) and public wireless power transfer, including for charging electric vehicle batteries.
This document is the first step in a process towards HD static and dynamic WPT. This document lacks specific requirements and solutions, for which field data is needed. This document is not intended to be a guideline to enable manufacturers to design systems with minimal assistance; the goal is to inform readers about many of the things to consider in addressing this market and is an outline for the SAE J2954/2 committee for continued work. Based on data, there will be much more detail in the next version of this document. This document represents experience from the SAE J2954 light-duty standard along with active participation of industry providers developing and deploying non-standardized HD wireless power transfer systems with the goal of creating standardized systems in the future.
SAE J2954/2 addresses unidirectional power transfer, from grid to vehicle; bidirectional transfer may be evaluated for a future document. This document is intended to be used in stationary applications (power transfer while vehicle is not in motion) and some dynamic applications.
SAE J2954/2 covers requirements for safety, performance, and interoperability. Further development of detailed requirements will be based on performance-based evaluations of candidate designs, including evaluations against electrical safety and human safety standards.
SAE J2954/2 also covers recommended methods for evaluating electromagnetic emissions, but the requirements and test procedures are controlled by regulatory bodies.
Electrified powertrains, in both light-duty vehicles (LDVs) and heavy-duty vehicles (HDVs), are projected to become more prevalent in production internationally due to environmental factors (such as GHG, CO2 emissions), regulations (such as the EU, China, U.S. EPA regulations, and the California ZEV mandates), as well as the increasing price of fossil fuels. The main benefit of electrified powertrains is eliminating or significantly reducing local emissions while increasing the overall well-to-wheels efficiency. In addition, autonomous vehicles are soon to be more commonplace to allow more convenient and safer transportation, especially in traffic settings and long-distance driving.
Standardized wireless power transfer (WPT, also called wireless charging) allows the battery electric vehicles (BEVs) and plug-in hybrid (PHEV) customer an automated, seamless, and more convenient alternative to plug-in (conductive) charging. Essentially, the customer simply needs to park in an SAE J2954-compatible parking space in order to charge the vehicle. WPT offers the additional advantage to autonomous vehicles enabling autonomous parking with alignment assistance and automated charging.
This SAE Information Report, SAE J2954/2, is the first guideline to assist in both static and dynamic wireless power transfer (DWPT) for fleets as well as preliminary demonstrations for HD WPT. Though there are more use cases than in LD WPT, the goal is to have the minimum complexity and to maximize interoperability between systems over the common use cases.
There are planned to be future SAE Recommended Practices following this document with the purpose of implementing validated specifications and test procedures to standardize wireless power transfer for wide scale commercialization.
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Off-board vehicle charging systems
Hybrid electric vehicles
Also known as: SAE J 2954/2
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