Truck & Off-Highway Engineering - December 2020 - 2

TECHNICAL
INNOVATIONS
ELECTRIFICATION

New SAE Wireless Charging standard is EV game-changer

SAE INTERNATIONAL
BOARD OF DIRECTORS
Todd Zarfos
President
Paul Mascarenas, OBE
2019 President
Jeff Hemphill
2021 President Elect
Pascal Joly
Vice President - Aerospace
Ken Washington, PhD
Vice President - Automotive
Michael Weinert
Vice President -
Commercial Vehicle
Andrew Jeffers
Treasurer

SAE International on October 22 announced
publication of the first global standard that
specifies, in a single document, both the electric vehicle and supply equipment (EVSE)
ground-system requirements for wireless
charging of electric vehicles (EV). The new
standard, SAE J2954 (www.sae.org/standards/
content/j2954_202010/), helps pave the way
for charging without the need for plugging in
- widely considered to be a key enabler for
accelerating the adoption of EVs and autonomous vehicles.
The new standard was more than a decade
in the making. SAE kicked off its pioneering
pre-competitive research at a time when few
contemporary electric cars existed and wireless
power transfer (WPT) systems for EVs were an
unproven concept. The SAE J2954 Wireless
Power Transfer and Alignment Taskforce
worked since 2007 to thoroughly vet and test
the technology, in partnership with government agencies, regulatory bodies and privateindustry groups including the American
Association of Medical Instrumentation
(AAMI), U.S. Dept. of Energy (DoE), the U.S.
Food & Drug Administration (FDA), automotive OEMs, Tier 1 suppliers and many others.
" Charging your EV should be as simple as
parking and walking away - the wireless
2 December 2020

charging SAE J2954 Standard gives freedom
and convenience to do exactly that, safely and
automatically, " stated Jesse Schneider, chair of
the SAE J2954 Task Force.
WPT systems work by parking in a wireless
charging spot, with the vehicle positioned over
an SAE J2954-compatible ground assembly
pad. After a communications handshake,
charging begins automatically without a physical corded connection. Power is transferred by
creating a magnetic resonance field between
the transmitting pad on the ground (wired to
the grid) and a receiving pad fitted on the underside of the vehicle. The energy crosses an
air gap (the ground clearance between the
pads) and is then converted from AC into DC
on the vehicle to charge the vehicle batteries.
The technology is a safe and efficient method
for transferring power from the AC grid supply
to the electric vehicle. Tests using a 10-in. (250mm) ground clearance have shown that WPT
systems operate at grid-to-battery efficiencies
of up to 94%. WPT with additional alignment
elements in SAE J2954 also fulfills the charging
requirements for autonomous EVs to charge
themselves without human interaction.
" The SAE J2954 standard is a game-changer
by giving a 'cook-book' specification for developing both the vehicle and charging infrastructure

Gregory L. Bradley, Esq.
Secretary
Landon Sproull
Jeff Varick
Rhonda Walthall
SAE International Sections

SAE International Sections are local
units comprised of 100 or more SAE
International Members in a defined
technical or geographic area. The purpose
of local Sections is to meet the technical,
developmental, and personal needs of the
SAE Members in a given area. For more
information, please visit sae.org/sections
or contact SAE Member Relations Specialist
Abby Hartman at abby.hartman@sae.org.

SAE International
Collegiate Chapters

Collegiate Chapters are a way for SAE
International Student Members to get
together on their campus and develop
skills in a student-run and -elected
environment. Student Members are vital
to the continued success and future of
SAE. While your course work teaches
you the engineering knowledge you
need, participation in your SAE Collegiate
Chapter can develop or enhance other
important skills, including leadership,
time management, project management,
communications, organization, planning,
delegation, budgeting, and finance. For
more information, please visit students.
sae.org/chapters/collegiate/ or contact
SAE Member Relations Specialist Abby
Hartman at abby.hartman@sae.org.

TRUCK & OFF-HIGHWAY ENGINEERING

WITRICITY

Wireless Power Transfer System example showing EVSE, Communications, Ground Assembly and Vehicle Assembly.

David L. Schutt, PhD
Chief Executive Officer

http://www.sae.org/standards/content/j2954_202010/ http://www.sae.org/standards/content/j2954_202010/ https://www.sae.org/participate/membership/sections https://www.sae.org/participate/membership/collegiate-chapters

Truck & Off-Highway Engineering - December 2020

Table of Contents for the Digital Edition of Truck & Off-Highway Engineering - December 2020