- Kanagawa Institute of Technology
- At Itako Lab. we are engaged in research on new controls for new energy
systems—primarily solar photovoltaic
and fuel cell power generation systems.
We also perform electronic analysis of the tone of classical guitars and
other musical instruments.
- ■Fields of specialization
- • Power Electronics Control
- • Musical acoustic engineering
- Visiting scientist, Technical University of Braunschuweig (Germany)
- Academic society affiliations
- The Institute of Electrical Engineers of Japan
- The Institute of Electrical Installation Engineers of Japan
- Japan Solar Energy Society
- Society of Instrument and Control Engineers
- The Electrochemical Society of Japan
- Society of Advanced Science
- FY2014: 20th ICEE Best Paper Award
- FY2013: 61st Electrical Science and Engineering Promotion Award (formerly
OHM Technology Award),
from The Promotion Foundation for Electrical Science and Engineering
- FY2010: 21st Paper Encouragement Award, from The Institute of Electrical
Installation Engineers of Japan
- Major articles(Journal)
- Relating to new energy
- “Proposal for Active PV Array to Improve System Efficiency During Partial
“Monitoring and Suppression of Typical Hot-Spot Phenomenon Resulting
from Low-Resistance Defects in PV string”,
IEEE Journal of Photovoltaics,Vol.8,Issue:6,pp.1809~1817(2018)
- Musical acoustics
- “Investigation of a New evaluation method (Octave factor) for Guitar
tones using FFT analysis” Journal of Advanced Science, Vol. 33, 33101-1～33101-5(2021)on
of optimum shape for an acoustic guitar by electroanalysys of tone quality”,
The Journal of the Acoustical Society of America 131, 3470 (2012)
- Patents awarded
- Japan: 8 patents in solar photovoltaic and fuel cell power generation
- America: 2 patents in solar photovoltaic power generation
- India: 1 patent in solar photovoltaic and fuel cell power generation
- China: 1 patent in solar photovoltaic power generation
- External funding
- Public funds
- Grants-in-Aid for Scientific Research(JSPS), Grants from Kanagawa Prefecture,
Japan Science and Technology Agency (JST),
and other entities
- Private enterprise
- Extensive research performed jointly with or commissioned by large, medium-size,
and small enterprises,
and under research grants
- Domestic and overseas consulting
- Public service record
- Member, Challenges Research Evaluation Section Committee, Executive Council,
Kanagawa Institute of Industrial Science and Technology
- Visiting scientist, Kanagawa Institute of Industrial Science and Technology
- Main lectures
- “High-efficiency control methods for solar photovoltaic and fuel cell power
Era Reform Council, July 3, 2018 (First Members’ Office Building of
the House of Representatives)
- “Research on maximum efficiency point detection (MEPD) of fuel cells”
10th Energy Creation, Collection, and Conservation Forum, KANAGAWA Industry
by Environment network Sagamihara Incubation Center Ltd. (SIC), March
8, 2016 (Kanagawa)
- “Introduction to power conditioner for solar photovoltaic system—Achievement
of high-efficiency solar photovoltaic system”
Japan Research Institute for New Systems of Society, July 21, 2014 (Tokyo)
- “Development of high-efficiency power conditioner for grid-connected solar
photovoltaic system” (lecture)
JST recommended seeds, New Technology Presentation Meeting
Japan Science and Technology Agency sponsorship, March 4, 2013 (Tokyo)
- “Energy creation and solar photovoltaic power generation” (Keynote lecture)
KSP, Inc., February 3, 2012 (Yokohama)
- “New MPPT control for solar photovoltaic systems”
The Institute of Electrical Engineers of Japan sponsorship, December
5, 2011 (Keio University)
- Research on New MPPT Control in Solar Photovoltaic Power Generation
- The operating point of a solar cell varies with the insolation intensity,
and other conditions, and control that enables operation at the most efficient
known as MPPT control, is therefore necessary.
In our laboratory, we perform research on a new MPPT control method
to eliminate the shortcomings of existing MPPT control.
If a shadow falls on a solar cell array of a solar photovoltaic system
or its panels face
in different directions, the output characteristics relative to the solar
cell voltage exhibit multiple peaks.
The MPPT algorithm of the existing P&O method poses the problem of
low peak point selection
and a consequent sharp reduction in output.
To eliminate this problem, we have developed a new scanning technique
that has enabled a new MPPT control method.
This new method can quickly read the I-V characteristics of the solar cell
for effective determination
and tracking of the maximum power point.
A power conditioning system (PCS) using this scanning principle in a household
solar photovoltaic system is marketed
by Hitachi Appliances, Inc. under the Hitachi brand.
Dragonwake Technology Co. Ltd. has also begun to market an MPPT controller
for a battery charger
that applies this scanning technique.
With this controller, the multiple peaks of output power caused by partial
shadowing or differing directions of solar cells
are scanned, the highest peak is detected and operation proceeds at that
substantially increasing the power output over that obtained by the conventional
- Research on Diagnosis Method of Hot Spots in Solar Cells
- A hot spot is one cause of solar cell module malfunction.
It involves a defect in a cell that causes a high partial or entire cell
in the event of a prolonged cell shadowing, which may cause
cell surface resin deformation or breakage and thus pose a risk of fire.
In our laboratory, we have applied the physical principles involved
in the related crystal defect (low-resistance defect) to develop
a new self-reverse current (SRC) test method for simple diagnosis of hot spots
This method can be used to identify a defective panel before it is incorporated.
It is simpler to perform than the existing method, which uses an infrared
The figure below shows defect detection in cells 21 and 23, on the monitor
of the test instrument developed at our laboratory.
- Research on System for Real-time Detection and Prevention of Hot Spots
in Solar Photovoltaic Systems
- In our laboratory, we have developed a new system for real-time detection and prevention of hot spots on panels.
This system, which involves scanning by an internal power conditioning
represents a new method for detecting solar cell abnormalities from periodically
measured I-V characteristics.
The system calculates the conductance of the low-resistance defect from
string I-V characteristics
to detect the occurrence of a hot spot and simultaneously prevent heat
generation while obtaining maximum output
by transferring the PCS operating point to a position where heat generation
does not occur.
In the figure below, the thermographs on the left and right show the images
obtained with the conventionl system
and the new system, respectively.
As can be seen, a hot spot occurs and the temperature rises to 115°C with
the conventional system,
but the temperature remains at the usual 32°C with the new system.
- Research on Active PV Arrays
- To control the maximum power point tracking (MPPT)
using power conditioning systems (PCSs),
the algorithm known as the P&O method can usually be used,
but if two or more peaks in the power output characteristic relative to
the solar cell voltage occur in the event of partial shadowing,
combined use, or differing directions of the panels,
the lower peak may be selected with a consequent sharp decline
Inter-string mismatching may also occur
if the optimum operating conditions differ between strings due to
partial shadowing or other impediments, thus making it impossible to
obtain operation at the maximum power point with MPPT control
To solve this problem, we propose an active PV array
which connects a unit to each panel on the input side of the existing PCS
in the emplaced PV system.
This allows us to obtain that can perform aggregation of power, which is
the sum of the maximum power of all panels
at the arbitrarily set voltage point of the array.
With this system, it is possible to select with certainty the maximum power
point despite partial shadowing or other impediments,
and thereby sharply increase the power generation efficiency even with
a PCS using a conventional P&O method.
- Research on High-efficiency Control of Fuel Cells
- A fuel cell is a power generation system that uses hydrogen as the energy
with heat and water as the only waste products of the power generation.
The hydrogen can be obtained, moreover, by electrolysis of water powered
by solar cells.
It is accordingly a clean method of power generation.
In our laboratory, we have developed a maximum efficiency point detection
method using the scanning technique that we developed for
solar photovoltaic systems, and applied it to fuel cells to reduce
hydrogen consumption and enable efficient operation of fuel cells.
- Research on Power Electronics Control
- In any electrical instrument, power control is obtained by semiconductor
power electronics control.
For semiconductor switching, the voltage, current, or another parameter
and feed back to cause generation of a PWM signal, generally using a microcomputer.
In our laboratory, we are engaged in research on control technologies
in a comprehensive range with various conversion circuits using microcomputers.
- Research on Electronic Analysis of the Tone of Musical Instruments
- Among classical guitars, for example, cheap instruments clearly
differ in tone from traditional high-quality ones.
In our laboratory, we perform electronic analysis of the tone
of musical instruments, for effective use of cheap materials
to produceinstruments that approach high-quality
instruments in tone.
- 1030 Shimo-ogino Atsugi Kanagawa 243-0292 Japan
- Kanagawa Institute of Technology, Itako Lab.
Project research support section
email@example.com(to Itako Lab.)