FTA - Report - WPT 2014 PDF
FTA - Report - WPT 2014 PDF
FTA - Report - WPT 2014 PDF
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This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information
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essential to the objective of this report.
Review and
Evaluation of
Wireless Power
Transfer (WPT)
for Electric Transit
Applications
AUGUST 2014
FTA Report No. 0060
PREPARED BY
SPONSORED BY
http://www.fta.dot.gov/research
Metric Conversion Table
LENGTH
VOLUME
MASS
megagrams
T short tons (2000 lb) 0.907 Mg (or “t”)
(or “metric ton”)
o 5 (F-32)/9 o
F Fahrenheit Celsius C
or (F-32)/1.8
1. AGENCY USE ONLY 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED
August 2014 Final Report; 10/2013 – 5/2014
4. TITLE AND SUBTITLE 5. FUNDING NUMBERS
Review and Evaluation of Wireless Power Transfer (WPT) MA-26-7200
for Electric Transit Applications Volpe TTA3A7/MJ091
6. AUTHOR(S)
Dr. Aviva Brecher, Principal Technical Advisor, and Mr. David Arthur PE, Division Chief,
Energy Analysis and Sustainability Division, Energy and Environmental Systems Technical Center
13. ABSTRACT
This research report provides a status review of emerging and existing Wireless Power Transfer (WPT) technologies applicable to electric
bus (EB) and rail transit. The WPT technology options discussed, especially Inductive Power Transfer (IPT), enable rapid in-station or
opportunity (boost) dynamic recharging of electric bus batteries for range extension and promise economic, convenience, and safety
benefits. Based on a comprehensive literature review, international and U.S. WPT bus and light rail systems deployed, demonstrated, or
planned are described, noting their respective providers, system specifications and attributes, and Technology Readiness Level (TRL).
FTA-funded WPT demonstrations currently underway or planned are also highlighted. Industry technical and safety standards (frequen-
cy, power, and interoperability) are currently in development. Regulations and consensus standards for emissions and human exposure
safety to electromagnetic radiation and fields (EMR/EMF) and protection from electromagnetic Interference (EMI) are reviewed. Mea-
sured EMR/EMR levels for various WPT electric bus systems comply with applicable occupational and public safety, health, and environ-
mental exposure standards. Information on the cost-benefit, reliability, durability, and safety of WPT infrastructure and vehicle systems is
scant. Research gaps, as well as challenges and opportunities for WPT commercial deployment, are identified.
17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF ABSTRACT
OF REPORT OF THIS PAGE OF ABSTRACT
Unclassified Unclassified Unclassified
TABLE OF CONTENTS
1 Executive Summary
3 Section 1: Background and Promise of WPT Technologies
6 Section 2: WPT Transit Technology Options and Providers
6 WPT Principles and Operational Requirements
7 IPT Technology IPT Charging for Buses
9 Shaped Magnetic Field in Resonance (SMFIR) Technologyfor Korean
Online Electric Vehicle (OLEV)
11
Wireless Advanced Vehicle Electrification (WAVE)
12
Bombardier PRIMOVE IPT for Electric Buses
13
Other WPT Technology Providers
17 Section 3: Demonstration and Deployment of WPT Electric Bus
and Light Rail Systems
17 Electric Bus WPT Demonstrations
22 WPT for LRVs
27 Section 4: SHE Standards and Regulations Relevant to IPT
27 Electromagnetic Spectrum and IPT Frequency Bands
28 International Technical Standards
28 U.S. Technical and Safety Standards for WPT
30 SHE Issues for WPT Emissions and Exposures, and Applicable Safety Standards
33 Measured WPT Magnetic Fields for Buses Comply with Safety Standards
35 Standards for Electromagnetic Compatibility and Interference (EMC/EMI) and
Operational WPT Safety Issues
37 Section 5: WPT Technologies for Transit Applications:
Status and Next Steps
LIST OF TABLES
29 Table 4-1: SAE Task Force for J2954 Wireless Charging Standard
31 Table 4-2: IEEE C95.1-2005 Broadband RF Exposure Safety Power
Density Occupational Limits
35 Table 4-3: Comparative SAR in FCC Regulations vs. ICNIRP Standard
39 Table 5-1: NREL TRL Scale Applicable to WPT Technologies
40 Table 5-2: Summary of WPT Pilots
42 Table 5-3 Summary of Transit WPT Research Issues and Needs
ABSTRACT
This research report provides a status review of emerging and existing Wire-
less Power Transfer (WPT) technologies applicable to electric bus (EB) and
rail transit. The WPT technology options discussed, especially Inductive Power
Transfer (IPT), enable rapid in-station or opportunity (boost) dynamic recharging
of electric bus batteries for range extension. In addition, WPT technology offers
the promise of economic benefits, greater convenience, and safety benefits. IPT
is a subset of technologies beneath the WPT umbrella in which there is resonant
inductive electromagnetic power transfer across an air gap. IPT is also the most
widely used of the WPT technologies and is based on a changing magnetic field
produced by alternating currents in the primary coil, inducing a voltage and cur-
rent in a secondary coil across an air gap. Based on a comprehensive literature
review, international and U.S. WPT bus and light rail systems that have been
deployed, demonstrated, or are planned are described. These descriptions note
their respective providers, system specifications and attributes, and Technology
Readiness Level (TRL). FTA-funded WPT demonstrations currently underway
or planned are also highlighted. Industry technical and safety standards (e.g., for
frequency, power, and interoperability) are currently in development. Regulations
and consensus standards for emissions and human exposure safety to electro-
magnetic radiation and fields (EMR/EMF) and protection from electromagnetic
Interference (EMI) are reviewed. The measured EMR/EMF levels for various WPT
electric bus systems comply with applicable occupational and public safety, health,
and environmental exposure standards. Information on the cost-benefit, reliabil-
ity, durability, and safety of WPT infrastructure and vehicle systems is limited. As
a result, this research report identifies research gaps, as well as challenges and
opportunities, for WPT commercial deployment.
Section 4 highlights the Safety, Health, and Environmental (SHE) issues associated
with WPT infrastructure and vehicles operation, as well as the applicable
regulations and voluntary technical and safety standards. FCC regulations, as
well as voluntary technical and safety standards, are currently in development
for WPT specifications, such as system frequency, power, field and radiation
emissions, and interoperability. Regulations and consensus standards are
reviewed that limit the electromagnetic radiation and fields (EMR/EMF) emissions
for human exposure safety assurance. Standards for protection of electrical
equipment and electronic devices from electromagnetic Interference (EMI) to
ensure electromagnetic compatibility (EMC) are also reviewed. Measured EMR/
EMF levels for various WPT electric bus systems demonstrated to date comply
with these applicable occupational and public safety, health, and environmental
exposure standards.
In Section 5, the Technology Readiness Level (TRL) is assessed for WPT transit
systems already deployed, demonstrated, or in the developmental phase.
Knowledge gaps, research needs, and major challenges to deployment of WPT in
transit are noted. Information on the cost-benefit, reliability, durability, and safety
of WPT infrastructure and vehicle systems is limited. The research gaps, as well
as challenges and opportunities for WPT commercial transit systems deployment,
are also identified, discussed, and summarized. Competing WPT technology
options promise to improve electric bus mobility, logistics, and user convenience
through shorter station dwell times for recharging electric bus batteries.
Potential advantages of WPT technologies include interoperability, ease-of-
use, and environmental sustainability, as well as lower lifecycle cost and higher
energy efficiency than conventional wired alternatives. WPT could also reduce
vehicle cost by allowing for smaller, lighter, and lower capacity batteries. WPT
technologies could also improve system operational safety, since road-embedded
infrastructure has no exposed high voltage cables or power outlets for plug-in
hybrid and electric buses. However, potential WPT benefits, such as the cost
of infrastructure construction, operation, and maintenance, as well as reliability
and durability, must first be quantified for in-service operation for adoption by
transit agencies. FTA-funded WPT bus projects will address key knowledge gaps.
In-service testing of competing WPT options for electric bus and rail applications
and quantitative data on WPT economic, safety, reliability, and potential benefits
are needed to overcome barriers to widespread commercialization and public
transit implementation.
This report is intended to review the status of wireless charging options for
electric bus and rail transit vehicles and to explore challenges to and promising
opportunities for WPT deployment. Knowledge gaps and research needs that
could be addressed by near-term Federal Transit Administration (FTA) Research,
Development, and Technology Demonstration Test and Evaluation (RDT&E)
are identified. Recent presentations by the FTA Office of Mobility Innovation2
have highlighted advanced transit bus and light rail vehicles (LRV) concepts with
diverse energy storage, traction power, and propulsion technologies. Several
multi-year Transit Investments in Greenhouse Gas and Energy Reduction
(TIGGER)3 and the Clean Fuels4 Program awards are intended to demonstrate
alternative WPT technology applications. Funded projects for rapid WPT
recharge of electric bus batteries include:
• A wire carrying an electric current produces a magnetic field around the wire
(Ampere’s Law).
• A coil intersecting a magnetic field produces a voltage in that coil (Faraday’s
Law).
Currently, wired chargers operate with total system efficiency of 50–70 percent
from the alternating current (AC) wall socket to the device battery, due to
losses in inverters and rectifiers, transformers, electronics, components,
and distribution.7 In contrast to conventional or wired conductive contact in
recharging EB batteries, WPT promises improved speed, convenience, safety,
and environmental benefits for a broad range of commercial applications, at
comparable or better efficiency. WPT technologies could extend the range of
electric buses and LRVs through either dynamic opportunity (or boost) charging
while moving over roadway charger plates or during station stops.
Section 3 presents illustrative bus, tram, and light rail WPT projects from
international and U.S. demonstrations and evaluations. If verified and validated
for in-service transit operations, the WPT options discussed in Section 2
could improve electric bus mobility, logistics, and user convenience through
shorter station dwell times for recharge. WPT could also reduce vehicle cost
by allowing for smaller, lighter, and lower capacity batteries. Assuming that basic
requirements of lower lifecycle cost and higher recharge efficiency of WPT over
conventional wired or conductive contact recharging can be met, the advantages
potentially offered by emerging WPT technologies, include interoperability, ease-
of-use, convenience, and environmental sustainability.8 WPT technologies could
also improve system operational safety, since road-embedded infrastructure has
no exposed high voltage cables or power outlets for plug-in hybrid and electric
buses. Based on the range of WPT demonstrations underway, and/or in-service
transit applications discussed in Section 3, their respective Technology Readiness
Level (TRL) is evaluated to project their near-term prospects.
Section 4 highlights the Safety, Health, and Environmental (SHE) issues associated
with WPT that need to be addressed, as well as applicable U.S. and international
regulations and voluntary technical and safety standards. Issues related to
the prevention and mitigation of potential SHE impacts for each WPT transit
implementation include:
• A critical review of the WPT technology providers for electric transit and
respective product performance.
• A survey of the proven capabilities of the diverse wireless charging
technologies suited to electric bus and LRV operating requirements and their
respective TRL.
Figure 2-1
IPT/WPT Principle11
In a transformer, the primary and secondary coils are connected by a magnetic
core—usually iron or ferrite—that traps the magnetic flux. For IPT, the magnetic
coupling of the primary transmitter infrastructure and the secondary on-board
receiver takes place across an air gap using electromagnetic radiation (EMR) for
power transfer. Figure 2-1 (left) shows how a magnetic field produced by the
primary loop (transmitter) embedded in the pavement induces a current in the
secondary coil (receiver) mounted under the bus. For optimal power transfer at
the resonance frequency, the transmitting and receiving coils must be precisely
positioned and aligned, with gap size restrictions to limit losses. In addition,
a closed circuit is needed to contain the magnetic flux and prevent stray
magnetic field emissions. This closed circuit would prevent adverse operational
SHE effects. Section 4 discusses the issues associated with the prevention and
mitigation of electromagnetic interference (EMI) from IPT charger pads with
other vehicle wireless functions, as well as potential RF heating of receiving
coils and RF charging of nearby metallic structures.
Figure 2-2
Conductix-Wampfler (now IPT Technology) IPT@Charge System14
Figure 2-2 shows the schematic of the IPT@ Charge system, which magnetically
couples the primary AC-powered coil embedded in the roadway to the
secondary pickup coil onboard the bus. These coils operate at a frequency close
to 15–20 kHz. The bus battery is inductively recharged across a small air gap
of approximately 1.5 inch (less than 4 cm) via a rectifier and voltage control
subsystem during station stops. This small air gap is optimal for efficient IPT
to minimize spreading and leakage of the magnetic field.15 The primary coil is
powered automatically only when the bus secondary coil is lowered mechanically
while above it. Depending on how often the opportunity to recharge occurs, IPT
allows for smaller, lighter and lower capacity batteries to be used, thus increasing
passenger load. Typically, the IPT energy transfer has exceeded 90 percent
efficiency when measured from the grid connection on the infrastructure side
to the DC output terminal on the bus battery side.16 The system is modular for
ease of handling and integration and to match the electric bus size. While 60 kW
modules are standard for infrastructure transmitters, the bus module size varies
with the length of the bus. A 30 kW module is used for buses up to 30 feet long
and a 60 or 120 kW module is used for 40-foot buses. Articulated buses would
require a third power module (up to a total of 180 kW).
Figure 2-3
Schematics of Infrastructure and Vehicle OLEV SMFIR Bus IPT Subsystems
Figure 2-3 (top) shows a detailed OLEV system schematic of the roadside
and road-embedded system segments (to power the primary transmitter),
communicating with the vehicle (secondary) pickup coil that feeds current via an
inverter (rectifier) to the rechargeable energy storage battery (RESS) and the
electric drive motor. The SMFIR chosen frequency for electric buses is 20 kHz,
whereas 60 kHz was chosen for rail WPT.22 Figure 2-3 (bottom) shows a more
complex view of the OLEV SMFIR system architecture. This bottom schematic
shows the onboard receiver coils with optimal inductance matching for efficient
WPT power transfer. The 60 kW of power is transferred from power lines to
the bus pickup module that then recharges the Kokam lithium ion phosphate bus
battery. The dynamically charged OLEV bus battery capacity is designed to be
only 20 percent of a conventional electric bus to reduce both battery weight and
cost.
Gumi, South Korea (see Section 3). The electric buses operating in South Korea
receive up to 100 kW power at 85 percent transmission efficiency across a 20 cm
fixed air gap between the road surface and the bus underbody.
OLEV uses both active and passive magnetic shielding to address the SHE issues
discussed below in Section 4. Shielding provides a number of benefits including
directing magnetic fields between primary and secondary coils, reducing EMF
emissions, and reducing exposure levels to passengers in the vehicle and in
stations all while ensuring efficient WPT.23
Noted improvements in IPT include the use of ferrite cores to trap and focus
magnetic fields produced, use of woven Litz wire windings on transmitter and
receiver coils to reduce electrical losses, along with advanced power electronics
for conversion and control. Other planned improvements27 include higher power,
frequencies (up to 140 kHz), mobile IPT (besides the current station recharging),
and increased misalignment tolerance from 8 inches at a 6-inch fixed air gap, to
10 inches at a 15-inch air gap.
With FTA TIGGER-3 funding, USU and the Utah Transit Authority (UTA) will
recharge the lithium iron phosphate batteries of a 40-foot bus during stops up
to 50 kW power. The bus has been delivered and the charging pads installed.
The bus has demonstrated inductive charging capability, and UTA will do further
testing before placing the bus into service over a 1.5 mile route. Operations are
scheduled for revenue service in April 2014. Besides the opportunity IPT charging
at the station, WAVE buses will also be conductively recharged overnight in the
garage. Therefore, its battery management system (BMS) is programmed to
accept both DC conductive and pulsed WPT power. More details on the planned
WAVE projects for Long Beach Transit [LBT], Monterey Transit System [MST],
and McAllen, TX are presented in section 3.
The schematic in Figure 2-4 shows the PRIMOVE IPT components onboard
the electric bus, including the power receiver pickup coils and a compensation
condenser to convert the magnetic field from the primary into an AC, inverters
(rectifier) to convert AC to DC for the battery, the RESS or battery, and a
Vehicle Detection and PRIMOVE segment control (VDSC) antenna to detect the
primary cables and control the on-off switch.
Figure 2-4
PRIMOVE Bus Wireless
Charging Diagram 31
Figure 3-7 is a PRIMOVE IPT system schematic used to power both electric
buses and light rail trams while stopped over the transmitter embedded in
the pavement. These components include primary cabling for power transfer,
magnetic shielding under the primary winding to prevent EMI to and from nearby
sources: a Vehicle Detection Segment Control (VDSC) cable that senses the bus
above it and turns on the power; a Supervisory ,Control and Data Acquisition
(SCADA) to provide information for system control and failure diagnostics,
inverters that convert the DC LRV supply voltage to the AC at IPT frequency
used by the system, and DC feed cables to supply power to the inverters.
Qualcomm HaloIPT33
In 2011, Qualcomm acquired HaloIPT, a New Zealand company (spun off by the
University of Auckland) that developed wireless induction charging technology
in the late 1980s for electric vehicles. In 2010, HaloIPT successfully charged
the Citroen EV and partnered with Rolls Royce to charge its luxury Phantom
EV. Currently, 100 EVs equipped for HaloIPT charging are being evaluated in
London.34 HaloIPT research showed that the Low Frequency (LF) bands widely
used for wireless electric vehicle charging applications must be optimized for
HaloIPT EV charging power transfer at 3.3–20 kW.35 Electric buses would need
much higher power transfer (60–120 kW boost to full charge output power.)
WiTricity36
In 2007, a Massachusetts Institute of Technology (MIT) faculty and researcher
team demonstrated and patented a WPT technology37 that uses magnetic
resonance (as opposed to induction) for power transfer over larger gaps. This
Highly Resonant (HR) WPT has achieved efficiency of over 90 percent via strong
magnetic field coupling of resonator coils at longer distances (15 cm to 2 meters)
for a broad range of potential applications.38 This technology was since been
optimized for higher tolerance to misalignment and greater gaps (for a mid-
range of 2 meters) between the receiver and transmitter coils. Measurements
of an RF magnetic field were performed to demonstrate compliance with limits
recommended by international human exposure safety standards, further
discussed in Section 4.39 Efficient HR-WPT recharging of batteries in small
electric vehicles—but not yet buses—was demonstrated in 2011,40 leading to
licensing partnerships with major automotive manufacturers (Toyota, Audi,
Mitsubishi Motors, and Delphi).41
EVATRAN PluglessPower42
EVATRAN has developed Plugless Power, a Level 2 (3.3 kW) inductive charging
EVSE for stationary rapid charging and is commercializing it in partnership with
Bosch. It consists of a vehicle adapter customized to each EV model placed under
the vehicle and a control panel linked to a 240 V, 30 amp electrical power supply
that provides power to the parking pad on the floor of the garage, guides the
driver to park over the pad, and displays the battery State of Charge. The system
technical specifications43 and safe operability were tested by the Department of
Energy (DOE) Idaho Engineering Lab,44 which confirmed that it complies with
EMF human exposure safety limits. To date, more than 1,500 hours of Plugless
Power testing were successfully completed45 with leading fleets of electric Chevy
VOLT and Nissan Leaf.
HEVO Power48 is another IPT contender for urban dynamic IPT charging
infrastructure. For instance, HEVO49 was developed (and is being tested) in
New York City manhole covers (round or square, as shown in Figure 2-5) that
integrate primary induction coils and antennae. These IPT manhole covers
activate to transfer power when EVs equipped with intelligent transceivers drive
over them at normal road speeds.47
Figure 2-5
EV Power Systems52 Other WPT technology
Figure 2-6
ORNL Static or
Dynamic WPT System
Recent, ongoing, and planned U.S. WPT bus demonstrations are described below:
Figure 3-1
CARTA Electric
Shuttle Bus
• The University of Utah (UU) campus in Salt Lake City and the Utah Transit
Authority have collaborated on demonstrating IPT for the Aggie campus
electric shuttle bus, using the UU-developed WAVE59 IPT technology.
The WAVE technology is also being adopted for charging the Long Beach,
California, electric buses60 as well as by the Monterrey-Salinas Transit (MST)
trolleys in California.
• The FTA TIGGER program funded Long Beach Transit (LBT) to purchase 10
electric buses to enable its wireless recharging. However, recent integration
challenges, implementation delays, and meeting Buy America requirements
have resulted in some open questions about this particular project.61,62
• The Maryland DOT, the Center for Transportation and Environment (CTE),63
and Howard County, Maryland, will operate three inductively-charged
electric buses on the Baltimore Green Route in Columbia, Maryland. This
project is in the early stages of implementation, with a second RFP having
been issued in December 2013 after the first June 2013 RFP was considered
non-responsive.
• McAllen, Texas,64 was funded in 2011 to equip three electric buses with the
OLEV Shaped Magnetic Field Resonance (SMFIR) technology developed by
KAIST. However, delays and problems in contract award to OLEV and later
to EV America led to a late award to WAVE in October 2013.65
• In 2012, FTA’s Clean Fuels Grant program also included two electric bus
awards66 using WPT. These projects include the MST trolley project, which
plans to use WAVE induction technology,67 and the Nashville Metropolitan
Authority68 purchase of electric buses and IPT station infrastructure (from an
as yet undefined provider).
Italy
The IPT Technology (formerly Conductix-Wampfler) for charging electric buses
in the station could be considered mature. It has been successfully deployed to
power more than 40 electric buses that have operated in Turin and Genoa for
more than a decade.70 In Turin, a fleet of 23 electric buses received boost charge
batteries while stopped in station to drop and board passengers. The Conductix-
Wampfler IPT® Charge system was rated at 60 kW and operated at 90 percent
power transfer efficiency. The reported annual cost of electricity per bus was
about $9K, a substantial gain compared to $50K fuel cost for a diesel-powered
bus.
Germany
Two electric buses are being tested for 12 months in Mannheim. The pad is
activated only when the bus is above it.71 Initially, the 12-meter Solo ebus will
be recharged during a 10-minute stop at terminus. When longer 18-meter
articulated Solaris buses are introduced, two more embedded IPT pads at
intermediate bus stops are planned for opportunity recharging. Electric ebuses
using the PRIMOVE IPT are recharged at more than 200 kW pads in public areas.
These particular buses are currently operating in Mannheim. A similar Solaris
Urbino electric bus equipped with Bombardier PRIMOVE wireless charging while
stopped in stations (Figure 3-2) started operations in Braunschweig, Germany, in
December 2013. Current plans are to also equip buses in Bruges, Belgium, with
this PRIMOVE IPT.
Figure 3-2
12m Solaris Urbino
Electric Bus in a
PRIMOVE-Equipped
Electric Bus 72
Photo ©Bombardier
Netherlands
In s’Hertogenbosch, Netherlands, a Volvo 86-passenger bus (see Figure 3-3)
has recharged its lithium iron phosphate batteries using Conductix-Wampfler
IPT since 2012 by using 120 kW of charging modules (2 modules of 60 kW EA)
during station stops.73 It is equipped with a mechanism to automatically lower the
on-board pickup coils to be close to the primary coil in the asphalt during battery
recharge opportunities for optimal IPT efficiency. Another bus is operating in
Utrecht.
Figure 3-3
Bus Using IPT
Technology Inductive
Charging While in
Station74
Switzerland
Asea Brown Bovery (ABB) Ltd. is testing an articulated electric bus serving the
city-to-airport shuttle in Geneva using the new flash charging concept named
Trolleybus Optimisation Système Alimentation (TOSA). It can provide charges
in 15-second bursts of 400 kW at selected stops along its route, using a charging
station that connects to the top of the vehicle.75 A full battery charge takes 3–4
minutes at the final stop.76 Such rapid recharging is very demanding even for
lithium ion bus batteries, both for WPT and in accepting regenerated braking
power. The BMS must aggressively manage the power input (charge) rate to the
battery as well as the delivery (discharge) rate, so as to prevent potential damage
to the batteries due to overcharge, overheating, and potential fire hazards.
Figure 3-4
ABB TOSA Flash-
charging System
South Korea
Two KAIST/OLEV wirelessly-recharged electric buses have been deployed and
are being evaluated in South Korea.78 The bus shown in Figure 3-5 is one of
the two operating in 2013 on a 24 km (15 mi) line in the city of Gumi, South
Korea. The advantage to the KAIST/OLEV system is that the rechargeable bus
battery is smaller than usual, at only 1/5 the size of a normal electric bus battery.
Recharging pads cover only 10–15 percent of the bus route.79
Figure 3-5
KAIST OLEV Electric
Battery Bus80
Japan
Hino Bus, a division of Toyota, developed and tested a fleet of hybrid electric
buses with lithium ion batteries and receptor coils under-carriage recharged by
pavement embedded induction coils in 2008. The buses operated on a 4.2 km
route at Haneda Airport in Tokyo. No technology details on the WPT frequency,
gap separation between bus and road embedded coils, power efficiency and
duration were found in 2008 references,81 and it is unclear if these buses are still
in operation.
for Nanjing, China.84 Available WPT technology options for light rail are briefly
reviewed below.85,86
Figure 3-6
IPT Technology
Gmbh (formerly
Conductix)
Installation
Schematic88
The electric current in the primary winding wayside component of the system
is shown in Figure 3-7. It creates a magnetic field, which induces the electric
current in the coil onboard the vehicle. The on-board components include a
pickup coil system and a compensation condenser (the PRIMOVE Power Receiver
System) underneath the LRV, which converts the primary winding magnetic field
into alternating current, further rectified into DC using an inverter. The cable-
powered primary segments are detected by the Vehicle Detection and PRIMOVE
Segment Control (VDSC) antenna in the vehicle and switched on. The PRIMOVE
system can provide a power output ranging from 100 kW to 500 kW, depending
on LRV-specific needs (length, the number of cars, geographic conditions and
range). It can be used for LRVs with length varying from 30 to 42 m, a gradient up
to six percent, and speeds up to 50 mph running on 270 kW power.
The PRIMOVE Light Rail Tram IPT was introduced in 2009 and first installed
for demonstration, test and evaluation on a 0.8km branch of the Augsburg,
Germany line serving the exhibition center since May 2010. Tests on this 200 kHz
induction loop spur line were completed in June 2012. There are planned IPT
wireless power options for several Movia metrocars and Flexity Freedom LRV
rail train-sets, though it’s unclear if they are already operating in inner cities in
Germany.90 The PRIMOVE “contactless” EcoActive track and urban LRVs (Figure
3-8) was also exhibited at APTA in 2011, seeking U.S. commercial deployment
opportunities.91
Image ©Bombardier
Figure 3-7
PRIMOVE Schematic92
Figure 3-8
PRIMOVE EcoActive
Light Rail
Image ©Bombardier
Though not strictly an IPT technology, APS power transfer enables the tram to
travel “wirelessly,” since the LRV power is supplied via a third rail embedded
in the roadway track. The energy is captured by two collector slippers located
under the tram center. For pedestrian safety, charging of the LRV in-ground
buried conductor segments is triggered only when they are covered by the
tram.94
Figure 3-9
Bordeaux
INNORAIL95
The APS advantage in historic inner city tracks is that overhead electric lines
are replaced by a ground level third rail that provides power via contact shoes
from in-ground power to trams equipped with an antenna and switch to activate
the power supply while above a track segment. Currently, five cities in France
have operational Citadis light rail transit systems powered wirelessly by the APS
in-ground supplies. Tours is the fifth city in France to introduce the APS wireless
technology for its Citadis tramway, after the first Bordeaux system (operating
since 2000, shown in Figure 3-9). Deployments in Angers, Reims, and Orléans (in
2006) followed.
Electromagnetic Spectrum
and IPT Frequency Bands
The use of the electromagnetic spectrum (Figure 4-1) is regulated by the
Federal Communications Commission (FCC)99 and frequency bands are carefully
allocated to enable and protect both public and commercial uses. Shared use of
spectrum bands may be permitted with safeguards protecting operational safety
and security (e.g., coding and encryption) that prevent EMI due to frequency
encroachment and, from increasing demand for wireless and mobile services.
FCC approval is needed for the use of frequency bands, including Industrial,
Scientific, Medical (ISM), and Intelligent Transportation Systems (ITS) applications.
It is necessary to prevent EMI with allocated radio services, automotive
electronics (i.e., keyless entry, tire pressure, ultrasonic garage remote) and
non-automotive systems (RFID, security devices).100 FCC regulations assure
the operational safety of new transmitters or susceptible devices by protecting
licensed or allocated frequency bands101 from EMI due to encroachment from
emerging new users.102 FCC regulations also require and enforce RFR limits from
licensed transmitters103 that ensure environmental and human exposure safety
from EMF and EMR.
Figure 4-1
Electromagnetic (EM) Spectrum
The lower the frequency of EM radiation, the longer the wavelength and the
size of the antenna required to transmit and received EM energy. The Very Low
Frequency band ranges from 3–30 kHz and corresponding wavelengths from
100–10 km. The LF band extends from 30–300 kHz. Below 100 kHz in the LF
band, the electric and magnetic fields can essentially be decoupled and treated
quasi-statically. At 1 MHz, the wavelength is 0.3 km, at 100 kHz, it is 3 km, but at
20 kHz used by several IPT providers, it is 15 km. In IPT systems, the transmitter
and receiver are closely spaced, or “near-field,” (within a quarter wavelength, or
tuned in resonance for optimal magnetic fields coupling efficiency).
Standards J2836/6 (use cases for wireless communications for PHEVs) and J2847/6
(wireless charging communications between PHEV and the utility grid) address
The Idaho National Laboratory (INL)110 developed WPT test protocols and
published technical and safety performance findings for WPT equipment.111 Human
exposure levels to magnetic fields as a function of distance were measured for
safety certification of the EVATRAN Plugless Power to facilitate deployment.
Table 4-1
SAE Task Force for J2954 Wireless Charging Standard112
Power Class
Classification (example for discussion) WPT1 WPT2 WPT3
L.D. Home L.D. Fast Charge Bus
Maximum ESVE Power Source 3.6 kW 19.2 kW 150 kW
The human exposure safety limits to RFR vary with frequency and are time
averaged over 6 minutes or 30 minutes, since the mechanisms for RFR (electric
or magnetic fields) interaction with biological systems also vary. Electric fields
are easily shielded or deflected, but magnetic fields penetrate body tissues to
different depths (the higher the frequency, the deeper the “skin depth”) and are
of greater concern to human safety and health. Potentially adverse bio-effects of
RFR depend on the Effective Radiated Power and the distance from the source;
they include hearing clicks, seeing phosphenes (light flashes), tissue heating
(thermal effects), neural stimulation, and contact shock and burns when touching
nearby metal objects.
Because the WPT frequency chosen by the new SAE J2954 TF is below 100
kHz, the ANSI/IEEE human exposure safety standards for this frequency range
applicable in the U.S.113 are:
The IEEE and ICNIRP or FCC MPE limits for human electric and magnetic fields
exposures in the workplace (occupational or controlled environments) and public
(uncontrolled environment) limit the RF energy deposition in the body. The Specific
Absorption Ratio (SAR) dose metric for EM energy deposition (by mass or volume)
is defined so as not to raise core (or organ, brain, limbs, etc.) temperature by more
than 1 degree Celsius. The IEEE 1528-2013116 recommended practice provides
updated test protocols to measure the peak spatial-averaged SAR induced in a
simplified head model by hand held cellphones and other transceivers, while C05.1-
2005 provides SAR measurement and estimation techniques for limbs and whole
body RF exposures as a function of frequency.
The IEEE SAR or power density MPEs are shown in Table 4-2 as they vary with frequency.
SAR limits are averaged RF energy absorption in tissue (4W/Kg for limbs and 2 W/kg in
head and trunk tissue). The FCC limit is more conservative (1.6 W/kg in 1 g tissue).
Figure 4-2
IEEE and ICNIRP
Human Exposure
Safety Limits
for Magnetic Fields
and Electric Fields117
The FCC has regulations on human exposure safety to EMR/EMF from 1996,
which are dated and currently being revised,120 as well as guidance on how to
comply with FCC regulations for licensed transmitters, or for ISM RF devices.121
The FCC is currently considering specific rulemaking and spectrum allocation
for wireless charging pads in automotive and consumer applications122 and is
participating in the SAE standards development effort discussed above.
For instance, in the 2012 FTA report 0028124 the CETE/UTC researchers
measured magnetic flux emissions for the wirelessly charged CARTA electric
shuttle using the Conductix-Wampfler technology, both inside and outside the
bus while it was charging at maximum power. In order to verify that public
safety is assured through compliance with the international ICNIRP standard,
the CARTA shuttle IPT charging EMF emission levels outside the bus (Figure
4-3, top left) and inside the bus (Figure 4-3, top right) were measured and
shown in green to be below the ICNIRP EMF public exposure safety limits
(Figure 4-3, bottom).
The RF magnetic fields for WPT bus systems measured to date were reported
to be well below ICNIRP and/or IEEE human exposure safety standards.
However, the leakage fields must be managed, as done for the OLEV SMFIR,
where vertical shielding is needed for the charger pad, and bus floor shielding
is needed as well. KAIST researchers investigated the effectiveness of several
magnetic field shielding materials at 20 KHz, and found that copper and
aluminum plates performed better than ferrite or magnetic steel.
Figure 4-3
EMF Emission
Levels127
The OLEV references cited in Section 2 indicate that both active shielding of
roadway primary fields and passive magnetic shielding in the bus floor chassis
is used to ensure compliance with the international ICNIRP human exposure
safety limits for magnetic fields (62.5 milligauss at 20 kHz). As mentioned above,
KAIST researchers found that aluminum and copper plates provided good
magnetic field shielding at 20 kHz, but it is not known what the best magnetic
field shielding materials are for vehicular WPT charging systems operating in
the 85 kHz band recently adopted by the SAE J2954 standard, and if any of the
providers have investigated field attenuation properties of various materials
near/below 100 kHz.
WiTricity has measured and reported the RF magnetic field strengths at various
locations where workers and the public might be exposed, and showed that
modeled SAR does not exceed FCC regulations and the IEEE and ICNIRP safety
standards.128
Table 4-3
Comparative SAR in FCC Regulations vs. ICNIRP Standard
Induced J
SAR (W/kg) Induced E
SAR (W/kg) SAR (W/kg) (mA/m2)
(Whole Body (V/m)
(Head/Trunk) (Limbs) (Central
Average) (All Tissue)
Nervous System
FCC 0.08 1.6 (1 g) 4 (10 g) – –
1.35 x 10 f
4
ICNIRP 2010 0.08 2.0 (10 g) 4 (10 g) –
( f in Hz)
f/500
ICNIRP 1998 0.08 2.0 (10 g) 4 (10 g) –
( f in Hz)
Another potential hazard is that EMI may induce high voltages and stray
currents in nearby metal structures (e.g., fences, bridges, pipelines, metallic
cars) and thus cause RF heating electric shock and/or burns to people touching
them. Leakage magnetic fields could also magnetize metal tools or debris in
roadways that could then become attached to the pavement or the bus, and
obstruct WPT during charging. In an effort to prevent these effects, some
providers are using debris and obstacle detection sensors as part of their
WPT design. Stray induced voltages and ground currents from WPT buried in
roadways or from wayside power supply equipment pose a known corrosion
hazard to buried gas lines and electrical cables and transformers, which must be
mitigated or prevented.
and evaluate WPT products for safe operability. There are also ongoing DOT
initiatives to evaluate the multimodal infrastructure implications of WPT,
explored in:
The ongoing FTA-funded electric bus pilot projects are expected to provide
valuable information and lessons learned on both static and dynamic IPT
infrastructure and electric vehicle system costs, reliability, safe operability
and durability in various climates and duty cycles. Furthermore, the multiple
and diverse transit WPT technologies and configurations described above
must also be proven efficient, cost-effective, reliable and safe before their
commercial deployment. Acceptance bus testing, such as the testing usually
performed at FTA’s Altoona, PA Test Facility, is also expected to provide
consistent operational and environmental performance data to enable a
comparison of emerging WPT bus technologies.
FCC licensing of WPT frequencies for public transit has not been finalized as
yet, nor have updated FCC human and environmental exposure regulations
been issued (public comments on an NPRM are currently being considered
and addressed). The SAE J2954 85 kHz band that was just adopted in 2013 as
standard frequency for vehicular WPT has not been used to date by any of
the technology providers for commercial bus or rail WPT systems. Although
compliance with this SAE industry standard is voluntary, it is likely that
most commercial developers and OEM integrators will have to modify their
equipment and subsystems in order to comply. They will have to optimize
power transfer control, efficiency and gap for this new standard WPT
frequency in the US before achieving TRL levels required for deployment.
Information on the actual capital investment and the O&M lifecycle costs of
various WPT technologies, broken down by subsystem (infrastructure and
vehicle system) could not be found in the literature. Most of these emerging
transit WPT systems were funded with front-end research, development and
technology public or university funds, or subsidized by the developers. The
economic issues for WPT’s competing options, as well as their in-service
reliability, availability and safety will become clearer over the next few years
of bus or rail test and evaluation prior to large scale commercial deployment.
using modular in-ground charge pads and bus receiver coils, over 12 years
and several generations of deployed wirelessly charged buses.
Table 5-3
Summary of Transit WPT Research Issues and Needs
Summary of Transit WPT Research Issues and Needs Safety Environment Health Economic
Standardize WPT charging infrastructure (frequency, power)
X X X X
for interoperability
Standardize WPT subsystem onboard bus for cost-effective
X X X X
retrofit and integration with legacy vehicles
Develop acceptance testing protocols for WPT transit
systems to verify safe operability, environmental compatibility,
X X
and compliance with applicable standards (SAE, IEEE) and
regulations (FCC, DOT)
Ensure workers and public health and safety for normal WPT
X X
system operations and for malfunction scenarios
Use the FTA Safety Management System (SMS) and failure
X
criticality analysis to compare WPT technology options
Quantify and compare capital, operation and maintenance
costs of WPT transit technology options using Lifecycle cost- X
benefit analysis (LCA)
Develop comparative data on WPT system reliability,
availability, maintainability, safety, health and environmental X X X X
impacts
Identify and develop Best Practices and Training for WPT
system preventive maintenance and safe handling to ensure X X
workers safety
Determine how to prevent, respond to, or mitigate EMI or
leakage EMF adverse impacts on human electronic implants X X X
and on wayside susceptible facilities
Perform scenario analysis of WPT infrastructure vulnerability X
X
to damage from heavy traffic and extreme weather
Since there may be important inherent safety issues associated with different
WPT technologies for both vehicles and infrastructure, a comparative
Failure Mode and Effects Analysis (FMEA) and Hazard Analysis are needed
to identify the safest architecture and operational options. Following this,
acceptance testing of buses or LRVs recharged by IPT (static, or dynamic)
MediaTek at http://www.mediatek.com/_en/wp/wireless%20charging.pdf.
9
See DOE “EV everywhere–a grand challenge in plug-in electric vehicles” at https://www1.eere.
energy.gov/vehiclesandfuels/pdfs/ev_everywhere/ev_everywhere_initial_framing_doc_081512_
final_2.pdf; and “Driving transportation to a cleaner future” at http://www.ksl.com/?sid=27588541.
10
See Wireless Power Consortium technology at http://www.wirelesspowerconsortium.com/
technology/basic-principle-of-inductive-power-transmission.html and Physics Central: Wirelessly
charged electric buses” at http://www.physicscentral.com/explore/action/electric-bus.cfm.
11
Source: www.physicscentral.com/explore/action/electric-bus.cfm.
See postings at www.ipt-technology.com/index.php/en and at http://www.conductix.us/en/
12
products/inductive-power-transfer-iptr.
See electric mobility at http://www.youtube.com/watch?v=OIIIVT0eAZM&list=PLAFBDF9D200
13
FAFED4&index=1.
14
Source: http://www.wampfler.com/index.asp?id=10&plid=474&e1=2&e2=12&lang=E.
Email communication and attachment received from Mathias Wechlin, IPT Global Product
15
Manager, on 1/16/14.
16
Personal communication from M. Wechlin, per footnote 11.
17
See www.olevtech.com.
See: a)“Design of wireless electric power transfer technology: Shaped Magnetic Field in
18
company/10569203/olev-technologies.
presentation at http://www.arpa-e.energy.gov/sites/default/files/documents/files/Wu%20
Wireless%20Power.pdf.
Clarifications regarding WAVE progress through Dec 2013 were received from Michael
26
130910bombardierbeginsoperationofthef.html.
See http://www.greencarcongress.com/2013/08/akasol-providing-li-ion-systems-for-bombardier-
30
primove-wireless-charging.html.
Source: http://primove.bombardier.com/application/bus/.
31
articles/detail/1610.
33
See http://www.qualcomm.com/solutions/wireless-charging/qualcomm-halo.
See “Qualcomm’s HaloIPT brings wireless charging for EVs,” January 2012 at http://phys.org/
34
news/2012-01-qualcomm-haloipt-tech-wireless-evs.html.
Presentation by Dr. Gregorz Ombach, Qualcomm VP Engineering at Qualcomm, “Wireless EV
35
charging, optimum operating frequency selection for power range 3.3. and 6.6 KW” at http://
www.ecce2013.org/documents/2013%20ECCE%20Special%20sessions/SS4/SS4.4_WPT_Ombach.
pdf.
See postings at http://www.witricity.com/ and “Witricity technology: The basics” at www.
36
witricity.com/pages/technology.html.
Aristeidis Karalis, J.D. Joannopoulos, and Marin Soljačić, "Efficient wireless non-radiative
37
mid-range energy transfer," Annals of Physics, Vol. 323, Issue 1, pp 34 – 48, April 27, 2007; Marin
Soljačić, MIT Physics Department http://web.mit.edu/physics/people/faculty/soljacic_marin.
html; and Andre Kurs, Aristeidis Karalis, Robert Moffatt, J. D. Joannopoulos, Peter Fisher, Marin
Soljačić, "Wireless power transfer via strongly coupled magnetic resonances,” Science, Vol. 317. no.
5834, pp. 83 – 86, July 6, 2006.
38
See Applications of Witricity technologies at http://www.witricity.com/pages/applications.html.
Dr. Morris Kesler, WiTricity Corporation, 2013: “Highly resonant wireless power transfer: Safe,
39
http://green.autoblog.com/2010/11/01/delphi-partners-with-witricity-on-automated-wireless-
charging-sy/.
42
See postings at http://www.pluglesspower.com/ for Plugless level 2 EV charging system
See http://www.advancedenergy.org/portal/evse/details.php?id=20&squery=!!mounting=Floor!ul
43
certified=.
44
“Idaho National Laboratory releases test results for Evatran’s Plugless Level 2 charging system”
at http://www.hybrid-ev.com/news/36347/idaho-national-laboratory-releases-test-results-for-
evatrans-plugless-level-2-charging-system.
“Evatran™ completes over 1500 hours of wireless charging trials with high profile fleets” at
45
http://www.pluglesspower.com/evatran-completes-over-1500-hours-of-wireless-charging-trials-
with-high-profile-fleets/.
“Eaton raises the bar in EV charging with its industry-leading DC HyperCharger,” December 9,
46
com/hevo-ev-charging-stations-manhole-covers/29474/.
53
See http://www.ecoupled.com/.
54
See www.powermat.com/about-us/.
See Wireless Charging System for Electric Vehicles at www.ornl.gov/File%20Library/Main%20
55
Nav/.../ID-201102667_FS.pdf.
56
See a) “Wireless charging system for electric vehicles,” Mike Paulus, John Miller, David Sims
at http://web.ornl.gov/adm/partnerships/events/Dec_Spark/Paulus_Wireless%20Power%20
Transmission%20Presentation%20-%20Paulus%20v2.pdf; b) John M. Miller: “ORNL demonstration
of in-motion wireless charging of vehicles,” DOT/RITA, Nov 2012 symposium; c) “ORNL
developments in stationary and dynamic wireless charging,” Dr. John M. Miller, Dr. Omer C.
Onar, Mr. P.T. Jones, September 18, 2013, IEEE 5th Energy Conversion Congress & Exposition,
Special Session: Advances in Wireless Power for Electric Vehicles, http://www.ecce2013.org/
documents/2013%20ECCE%20Special%20sessions/SS3/SS3.4_WPT_Miller_Onar.pdf.
See “FTA FY2011 Sustainability Awards (including TIGGER and Clean Fuels) at www.fta.dot.gov/
57
documents/2011_TIGGER-CF.FINAL.pdf.
58
See “Wayside charging and Hydrogen hybrid bus: extending the range of electric shuttle buses”
at www.fta.dot.gov/documents/FTA_Report_No._0028.pdf.
See WAVE technology details at http://www.waveipt.com/about and http://www.waveipt.com/
59
content/technology
60
See http://www.treehugger.com/clean-technology/long-beach-get-wirelessly-charged-electric-
buses.html; and WAVE news at http://www.waveipt.com/blog/charging-forward-long-beach-
transits-all-electric-bus-program-gets-under-way.
See http://lbbusinessjournal.com/long-beach-business-journal-newswatch/1836-long-beach-
61
transit-staff-finds-problems-with-new-zero-emission-bus-frames-at-chinese-factory.html
See http://www.masstransitmag.com/news/11354120/chinese-firm-may-lose-bus-contract-
62
with-long-beach?utm_source=MASS+NewsViews+Newsletter&utm_medium=email&utm_
campaign=MASS140313002.
63
See http://www.cte.tv/programs.html and http://livegreenhoward.com/land/transportation/.
See http://www.brownsvilleherald.com/news/local/article_7a06ced6-ffd7-11e2-93c2-
64
001a4bcf6878.html?mode=print.
65
See “New proposals, new hurdles for McAllen’s electric bus project,” The Monitor, Oct 8, 2013
at http://www.themonitor.com/news/local/article_be79c73e-2f9e-11e3-91b7-0019bb30f31a.html
66
See list of projects at http://www.fta.dot.gov/grants_14835.html.
67
See http://www.waveipt.com/portfolio.
68
See http://www.nashvillemta.org/amp/pdf/news39.pdf.
See “Wirelessly-powered road-charged electric buses are online!” August 19, 2013, at http://
69
beta.fool.com/bamckenna/2013/08/19/worlds-first-road-charged-electric-buses-are-onlin/43776/,
70
See: a) “In Italy, Electric buses wirelessly pick up their power,” NYTimes.com, May 30, 2012,
at http://wheels.blogs.nytimes.com/2012/05/30/in-italy-electric-buses-wirelessly-pick-up-their-
power/?_r=0; b), “Inductive charging: It’s charged (a few) Italian buses for 10 years now,” June 5,
2012, at www.greencarreports.com/news/1076704_inductive-charging-its-charged-a-few-italian-
buses-for-10-years-now; c) “Italy’s wireless electric buses” at http://www.electricforum.com/
electric-cars/italys-wireless-electric-buses.html.
See “Electric buses test wireless charging in Germany,” 03/14/13, at www.wired.com/
71
n20130910bombardierbeginsoperationofthef.html.
73
See a) “Netherlands: Wireless e-bus charging trials under way,” October 11, 2012, Automotive
World at http://www.automotiveworld.com/analysis/96455-netherlands-wireless-e-bus-charging-
trials-under-way/; and B) “Field trials in the Netherlands: 12-meter electric bus is going to run 288
km a day in regular service with inductive opportunity charging” at http://www.conductix.com/
sites/default/files/downloads/PR_12-10-01_12-meter_Electric_Bus_in_Regular_Service_with_
Inductive_Opportunity_Charging.pdf.
74
Source: http://www.automotiveworld.com/analysis/96455-netherlands-wireless-e-bus-charging-
trials-under-way/.
75
See http://www.electric-vehiclenews.com/2013/05/abb-unveils-wireless-electric-bus-with.html.
See ABB technology can flash-charge bus in 15 seconds, May 31, 2013, at http://www.
76
electronicsnews.com.au/news/abb-technology-can-flash-charge-electric-bus-in-15
See IPT Technology news at www.ipt-technology.com/index.php/en/news-en and www.bbc.
77
co.uk/news/technology-25621426?
See “OLEV Technologies zero emission transportation solutions case studies” at http://olevtech.
78
english/01_about/06_news_01.php?req_P=bv&req_BIDX=10&req_BNM=ed_news&pt=17&req_
VI=4404.
See .http://www.kaist.edu/english/01_about/06_news_01.php?req_P=bv&req_BIDX=10&req_
80
BNM=ed_news&pt=17&req_VI=4404
See “Electric bus with a wireless charging system” at www.greenpacks.org/2008/03/11/electric-bus-
81
with--a-wireless-charging system/; and “Hino’s answer to slow recharging times is to go plugless, but
how efficient?” at www.wired.com/autopia/2008/03/hinos-answer-to/; “Wireless Hino Hybrid a hit
at Haneda” at green.autoblog.com/2008/02/23/wireless-hino-hybrid-a-hit-at-haneda/.
82
“Development and performance evaluation of an electric mini-bus equipped with an inductive
charging system,” T. Pontefract, K. Kobayashi et al. in Proc. FISITA 2012 World Automotive
Congress at linkspringer.com/chapter/10.1007/978-3-642-33741-3_15#page-1; and “Real-world
performance evaluation and optimization of a short-range, frequent charging electric bus system”
at www.f.waseda.jp/kamiya/.
83
See benefits of rail IPT at http://primove.bombardier.com/application/light-rail/.
84
See http://www.dailytelegraph.com.au/news/nsw/sydney8217s-new-light-rail-system-will-feature-
futuristic-wirefree-trams-to-ensure-clutterfree-streets/story-fni0cx12-1226714773633
85
See “New technologies provide alternatives to overhead wires,” April 7, 2010, at http://
greatergreaterwashington.org/post/5445/new-technologies-provide-alternatives-to-overhead-
wires/ and “Fully wireless streetcars feasible soon, but not today,” May 7, 2010, at http://
greatergreaterwashington.org/post/5774/fully-wireless-streetcars-feasible-soon-but-not-today/
and “Light rail without wires,” Transportation Research Board at onlinepubs.trb.org/onlinepubs/
circulars/ec058/15_02_Swanson.pdf.
86
See “Here come the streetcars,” Railway Age, April 08, 2013 at http://www.railwayage.com/
index.php/passenger/light-rail/here-come-the-streetcars.html and “Wireless power systems
enhance global tram projects,” Metro Magazine, May, 2009 at www.metro-magazine.com/article/
story/2009/05/wireless-power-systems-enhance-global-tram-projects.aspx.
87
See www.ipt-technology.com/index.php/en and IPT Rail at http://www.conductix.us/en/products/
inductive-power-transfer-iptr/inductive-power-transfer-iptr-rail.
88
Source: http://www.conductix.us/en/products/inductive-power-transfer-iptr/inductive-power-
transfer-iptr-rail?parent_id=5798.
89
See http://us.bombardier.com/us/press_release_06092011.htm.
90
See http://www.railway-technology.com/projects/bombardier-primove-light-rail-trams-germany/.
See http://us.bombardier.com/us/press_release_03102011.htm.
91
92
Source: http://primove.bombardier.com/application/light-rail/.
93
See http://www.alstom.com/Global/Transport/Resources/Documents/Brochure%20-%20
Infrastructure%20-%20English%20.pdf
94
See http://www.alstom.com/transport/news-and-events/events/uitp-2013-/outdoor-display/aps-
citadis-tours/ and http://www.alstom.com/press-centre/2006/9/Orleans-in-France-selects-Alstom-
for-its-second-tram-line-opting-for-APS-20060918/.
Source: http://invisiblebordeaux.blogspot.com/2011/12/bordeaux-trams-underground-power.
95
html.
See http://w3.siemens.com/smartgrid/global/en/products-systems-solutions/rail-electrification/
96
dc-traction-power-supply/pages/hybrid-energy-storage-system.aspx.
97
See Siemens launches new energy storage systems for trams, April 2009 at http://www.railway-
technology.com/news/news52360.html; and 2009 press release at http://www.siemens.com/press/
en/pressrelease/?press=/en/pressrelease/2009/mobility/imo200903024.htm.
See press release “KAIST develops wireless power transfer technology for high capacity transit,”
98
47 CFR Parts 1, 2, and 15, et al., Human exposure to radiofrequency electromagnetic fields;
Reassessment of exposure to radiofrequency electromagnetic fields limits and policies; Final rule
and proposed rule at http://www.federalregister.com/Browse/AuxData/33AD2CD8-A209-4920-
A6BE-AFC396366B36.
101
See http://www.fcc.gov/encyclopedia/radio-spectrum-allocation.
102
See http://www.fcc.gov/guides/interference-defining-source.
103
See postings at http://transition.fcc.gov/oet/rfsafety/background.html.
104
See ISO 15118-1:2013, Road vehicles—Vehicle to grid communication interface—Part
1: General information and use-case definition at http://www.iso.org/iso/catalogue_detail.
htm?csnumber=55365; and https://www.iso.org/obp/ui/#iso:std:iso-iec:15118:-1:ed-1:v1:en.
105
See IEC TC69 standards for electric road vehicles at http://www.iec.ch/dyn/www/
f?p=103:14:0::::FSP_ORG_ID,FSP_LANG_ID:8538,25.
See J2953/1“Test procedures for the Plug-In Electric Vehicle (PEV) interoperability with Electric
106
task force announces agreement on frequency of operation and power classes for wireless power
transfer for its electric and plug-in electric vehicle guideline,” November 13, 2013, at http://www.
sae.org/servlets/pressRoom?OBJECT_TYPE=PressReleases&PAGE=showRelease&RELEASE_
ID=2296.
108
Theodore Bohn, “PEV charging standards status, including AC, DC and wireless technologies,”
at 2013 SAE/GIM http://www.sae.org/events/gim/presentations/2013/pev_charging_standards_
status.pdf.
See “SAE International Task Force announces agreement on frequency of operation and
109
power classes for wireless power transfer for its electric and plug-in electric vehicle guideline,”
November 13, 2013, at http://www.sae.org/servlets/pressRoom?OBJECT_TYPE=PressReleases&P
AGE=showRelease&RELEASE_ID=2296.
“Update on DE FOA 000667 wireless charging for DE-FOA-000667 wireless charging for
110
electric vehicles,” Jim Francfort, Brent Warr, Richard Carlson, at CERV 2013, Park City, Utah,
February 2013 at http://www1.eere.energy.gov/vehiclesandfuels/avta/pdfs/wireless/cerv_2-13.pdf.
“INL testing results: PLUGLESS TM wireless charging system by Evatran Group Inc. at Plug-In
111
publications/facts/fs304/en/; and the WHO 2010 Research Agenda for Radiofrequency Fields at
http://www.who.int/peh-emf/research/agenda/en/index.html.
116
See http://standards.ieee.org/findstds/standard/1528-2013.html.
Source: “Very-low-frequency and low-frequency electric and magnetic fields associated with
117
electric shuttle bus wireless charging,” Tell RA, Kavet R, Bailey JR, Halliwell J., in Radiation
Protection Dosimetry, September 15, 2013, at http://www.ncbi.nlm.nih.gov/pubmed/24043876
See https://www.osha.gov/SLTC/radiofrequencyradiation/ and NIOSH guidance at http://www.
118
cdc.gov/niosh/topics/emf/.
119
See http://www.acgih.org/tlv/AIHce_Slides_6.pdf.
See Federal Register, Vol. 78 No. 107, June 4, 2013, Federal Communications Commission, 47
120
CFR Parts 1, 2, and 15, “Human exposure to radiofrequency electromagnetic fields; Reassessment
of exposure to radiofrequency electromagnetic fields limits and policies; Final rule and proposed
rule” at http://www.federalregister.com/Browse/AuxData/33AD2CD8-A209-4920-A6BE-
AFC396366B36.
“FCC human and environmental RFR safety regulations and FAQs,” posted at http://www.fcc.
121
process: Question: What rules regulate short distance wireless inductive coupled charging
pads or charging devices?” at https://apps.fcc.gov/oetcf/kdb/forms/FTSSearchResultPage.
cfm?id=41701&switch=P.
See http://www.fda.gov/medicaldevices/deviceregulationandguidance/guidancedocuments/
123
ucm077210.htm.
See http://www.fta.dot.gov/documents/FTA_Report_No._0028.pdf, “Wayside charging and
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hydrogen hybrid bus: Extending the range of electric shuttle buses,” September 2012.
a) “Very-low-frequency and low-frequency electric and magnetic fields associated with electric
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shuttle bus wireless charging,” Tell RA, Kavet R, Bailey JR, Halliwell J., in Radiation Protection
Dosimetry, September 15, 2013, at http://www.ncbi.nlm.nih.gov/pubmed/24043876; and b) “ELF
magnetic fields in electric and gasoline-powered vehicles,” Bioelectromagnetics (BEMS) 34/2, 156-
161 (2013), by Ric Tell, G, Sies, J. Smith, J. Sahl and R. Kavet (EPRI), Bioelectromagnetics, February
2013, 34(2):156-61 at. http://www.ncbi.nlm.nih.gov/pubmed/22532300.
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“Magnetic fields,” DS9200-0030-EN, from Mathias Wechlin, January 16, 2014.
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Source: FTA report 0028 at www.fta.dot.gov/documents/FTA_Report_No._0028.pdf.
See discussion and data in Dr. Morris Kesler, WiTricity Corporation, 2013, “Highly resonant
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system” at .
IEEE 1900.2-2008, “Recommended practice for the analysis of in-band and adjacent band
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“Guide on the use of standards for the implementation of the EMC directive to apparatus," 2009.
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See DOD and other EMI/EMC standards list at http://www.radioing.com/eengineer/military.html.
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See International Electrotechnical Commission (IEC) Standard IEC 62110 ED. 1.0 B:2009,
Electric and magnetic field levels generated by AC power systems—Measurement procedures
with regard to public exposure, and SAE J1113/1, Electromagnetic compatibility measurement
procedures and limits for components of vehicles, boats (up to 15 m), and machines (except
aircraft) (16.6 HZ to 18 GHz).
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See a) “Wirelessly charged electric buses” at www.physicscentral.com/explore/action/electric-
bus.cfm; b) “Charged: What’s up with wireless charging” at http://chargedevs.com, Feb 19, 2013;
c) “Pulling the plug on conventional charging,” Physics Central, 2010, at http://www.physicscentral.
com/explore/action/inductivecharging1.cfm; d)“Companies devise wireless charging for electric
buses,” Wall Street Journal, August 27, 2013, at blogs.wsj.com/digits/2013/08/27/companies-devise-
wireless-charging-for-electric-buses/.
See: “The convenience of wireless charging: It’s just physics.” White paper by M. Estabrook,
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142
Adapted from http://www.eenews.net/stories/1059989839/print).
See “Companies devise wireless charging for electric buses,” WSJ blog, August 27, 2013, at
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http://blogs.wsj.com/digits/2013/08/27/companies-devise-wireless-charging-for-electric-buses/tab/
print/.