Spacial
Feature
1
Pursing DAIHEN Value
Advancing into the market for wireless power transfer systems
We have developed revolutionary products incorporating
DAIHEN proprietary technology for the market for wireless
power transfer systems. These innovative devices are drawing
attention as integral to the evolving social infrastructure.
Wireless power transfer systems incorporate a technology for literally sending electricity without the need for electric
wires. They are being used to charge mobile phones and are employed in induction heating (IH) cooking appliances,
but until recently this technology was limited to small power transfer systems positioned in close proximity. However, in
2006, the Massachusetts Institute of Technology (MIT) succeeded in supplying power to an object more than several
meters away, all at once extending the potential for application development. DAIHEN has developed dedicated RF
generator systems that can efficiently supply large amounts of electricity and is working toward commercialization in
the market for wireless power transfer systems, which is attracting growing attention worldwide.
Wireless power transfer systems are expected to target the field of social infrastructure
Wireless power transfer systems are attracting attention
because they are now capable of sending larger amounts of
power to a remote location than has been possible
conventionally. This technology now has the potential to
supply large quantities of electricity without electric wires.
One application is recharging of electric vehicles. For
example, being able to supply power while the vehicle is
moving or stopped at a traffic signal raises the possibility of
using smaller batteries or traveling extended distances. In
addition, wireless battery charging when a vehicle is parked
eliminates the inconvenience of repeatedly connecting a
power cord. If this technology is applied to a railway,
infrastructure such as overhead wires for supplying power to
the train become unnecessary, greatly reducing railway
construction costs.
Thanks to MIT’s successful experiment, the scope of
application of wireless power transfer systems, conventionally
limited to small household appliances, is about to be
extended to social infrastructure. As a result, competition in
the development of technologies and methods for the design
of wireless power transfer systems is heating up between
companies possessing the relevant technologies.
Innovations made possible with wireless power transfer systems
Power
transferred to
a moving
vehicle
Meeting the challenge of fusing DAIHEN’s
unique technology
While DAIHEN is primarily a manufacturer of transformers, we
also produce RF generators and have accumulated the power
conversion technology and RF-related technology required for the
generators of wireless power transfer systems. Therefore,
following the success of the MIT experiment, we focused on the
development of the generators required for wireless power
transfer systems, as they hold the potential for a promising new
business utilizing DAIHEN technologies.
Immediately following the start of this initiative, we succeeded
in developing a power transfer system utilizing the same magnetic
field resonance method as used by MIT in our experimental
facilities, which we assembled through trial and error. Thereafter,
we explored theoretical and practical applications.
We launched our efforts in 2013 by establishing the relevant
division. By April 2014, we had developed and introduced a power
generation system (1 kW 13.56 MHz) for research purposes.
The characteristics of the RF generator system for DAIHEN’s
wireless power transfer system are provided below.
❶ Provides high efficiency at low cost.
❷ Accommodates “position gap” between power
transmission equipment and power receiving equipment.
❸ Power transmission and receiving devices feature
compact designs.
Transformer
Power
Transmission &
Distribution Products
Business Segment
○ Power conversion technology
○ Power receiving and
RF
generator
distribution facilities
○ High-power & high-efficiency
inverter technology
Advanced
Component
Business Segment
○ RF-related
technology
○ Sensor
technology
RF Generator System
Target of Power Transfer
13.56 MHz transmission
coil
Electrical
outlet
Receiving circuit
Power
50/60 Hz
Power
receiving
coil
Battery
9
CSR Report 2014
Nagaoka University of Technology
Wireless transmission
of power
RF
generator
system
Developed
by DAIHEN
Power
transmission
coil
Joint research on supplying power
while in motion
Power
receiving
coil
High-efficiency
RF rectifying
circuit
Power
receiving circuit
Subject to power supply
Electric vehicles,
household appliances, etc.
Battery
Joint research on
high-efficiency transmission
Tokyo University
Industrial PV inverter
Welding
machine
Welding &
Mechatronics
Business Segment
○ Inverter
technology
○ System design
technology
Industrial
robot
DAIHEN introduces an RF generator system for a wireless
power transfer system incorporating proprietary technology.
A magnetic field is created when electricity flows through a coil (winding). When a second coil is placed in this
magnetic field, electricity flows to this coil. This phenomenon, called “electromagnetic induction,” was discovered by
British physicist Michael Faraday in the 19th century.
DAIHEN’s principal product line, transformers, as well as the wireless power transfer system currently in
development, both employ this principle of electromagnetic induction. Although transformers have a core and the
wireless power transfer system does not utilize a core, both rely on the principle of electromagnetic induction.
Joint research on power receiving circuitry
Nara Institute of Science
and Technology
Semiconductor
transfer robot
Wireless power transfer systems
We are currently working on commercialization of a
wireless power transfer system by utilizing a generator
system for research that we developed in cooperation with
universities and companies conducting research on wireless
power transfer systems. Of course, wireless power transfer
systems have applications beyond electric cars. In addition,
the variety of potential applications includes medical devices
as well as transportation equipment such as a railroads and
automatic guided vehicles.
Therefore, in order improve transmission efficiency further
and increase the ease of application, we are promoting
research collaboration between industry and academia on
power receiving circuitry, high-efficiency transmission, and
supplying power while in motion.
As a manufacturer of power generation
systems, DAIHEN offers high-power
kilowatt-class RF generators.
RF matching
box
Multiple
simultaneous
power
transfers
Promoting collaborative research with
application to electric vehicles
RF generator system
for research
(1 kW 13.56 MHz)
Popularizing our parallel 2-track method
As electric vehicles become more popular, the market for wireless power transfer systems will likely become very
promising in the future. This has inspired many companies to participate in this market, and competition in the development
of wireless power transfer systems is already under way. While the various approaches in use have both good points and
bad points, when we describe the wireless power transfer system in one phrase, the “parallel 2-track method” that DAIHEN
has adopted is advantageous and has become popular for the easy installation of its facilities and its transmission efficiency,
which is not readily affected by the positional relation.
Technology for controlling a high-powered RF generator is indispensable for our parallel 2-track
method, and DAIHEN has a track record of years of successful development of RF generators. Our
Group boasts many superior engineers that give us a great advantage in this area.
Currently, a large-scale shielded room is under construction that
will enable running tests of electric vehicles; it is scheduled to be
Yasuaki Tatsuta
completed by the end of the year. In cooperation with automakers and
Department of High Frequency
universities, we will promote technological development toward future
Technology Development
Research & Development Division
commercialization of a power supply system for electric cars.
CSR Report 2014
10