Development of Contact-Loss
Measuring System Using Ultraviolet
Ray Detection
Pantograph Catenary Interaction Framework for Intelligent Control
December 8th ,2011
Amiens, France
Takamasa HAYASAKA
Railway Technical Research Institute
Railway Technical Research Institute
Table of Contents
1. Motivation
Contact loss, measurement, conventional
system and technical issues
2. Development Japanese Contact-Loss
Measuring System
Development of new measuring system
3. Verification Tests and Results
Verification test of the new measuring system
4. Summery and Future plane
Railway Technical Research Institute
Feature of Japan and Japanese Railway Network
Feature of Japan
Distance：3,000km
Area：380,000 km2
Population：128,000,000
Aomori
Feature of Japanese Railway Network
All Railways：10,000km
High-speed railway：2,400km
福
島
Osaka
Kagoshima
Tokyo
Since many people live along
railway, railway companies pay
attention to noise generation.
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Influence of Contact-loss
What is problem by contact-loss?
At the moment of arc discharge
occurring and extinction, it generates
noise.
moreover
Current collecting materials take a
damage during arc discharge.
Contact wire
Pantograph head
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Prevent Contact-loss
We make an effort to prevent contact-loss.
In other words, we are trying to improve current collecting character.
For example,
Shape
Air Conditioning
unit
Developing new types of
overhead contact system
Developing new types of
pantograph system
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Necessity of Contact-loss Measurement
We need those researches to prevent contact losses, however,
we also need to know where contact losses occur,
for preventing unusual wear of current collecting material.
Contact-loss is measured in various situations such as
certification of a new line, line test for a new type train
set, inspection of overhead contact wire and so on.
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How to Measure Contact-loss
There are some measurement ways to detect arc light. One
example of the measurement for arc light detection system
installed on a train is shown below.
Pantograph
Acquisition device
Contact wire
Acceptor
detector
Optical fiber
・Optical fiber and acceptor are fixed on the train roof.
・The optical fiber is connected to a detector installed in the train.
・The detector is connected to data acquisition system.
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Conventional System to Detect Arc Light
Arc light consists of some optical wave lengths, though, the ways of arc
light detection are two types from view points of optical wave length.
One is ultraviolet rays detection, the other is visible rays detection.
There is the difference in optical fiber of these systems.
Output
Ultraviolet rays detecting system
Ultraviolet rays
Visible rays
Infrared rays
Quartz optical fiber Interference Detector
Arc light
filter
Output
Visible rays detection system
Ultraviolet rays
Visible rays
Infrared rays
Plastic optical fiber
Detector
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Japanese Conventional System to Detect Arc Light
In Japan, railways company used to the visible rays detection systems.
But the system has a disadvantage that it can not measure arc light in
daytime.
So, they hoped to adopt the ultraviolet rays detection system.
However, also the ultraviolet rays detection system has a disadvantage
that it uses quartz optical fibers.
Optical fibers
Transmittable
wave length
Handling
Price
Quartz
All wave length
Bad
High
Plastic
Visible rays,
infrared rays
Good
Low
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Development of New System
In development of Japanese contact-loss measuring system using
ultraviolet ray detection, we tried adopting plastic optical fibers that can
not transmit ultraviolet rays.
In other words, we decided to use the visible rays detection system for
development of contact-loss measuring system using ultraviolet ray
detection.
If we can transform ultraviolet rays to visible rays in front of plastic
optical fibers, we can use the system for contact-loss measuring system
using ultraviolet ray detection.
Transform
Output
Ultraviolet rays
Visible rays
Infrared rays
Plastic optical fiber
Detector
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How to Transform Wavelength
We developed a wavelength transformer that transforms
ultraviolet rays to visible rays.
Wavelength transformer
Ultraviolet
ray
Visible
rays
Plastic optical
fiber
Interference filter
Wavelength
transformer
Fluorescent glasses
If we attach the transformer to plastic optical fiber’s acceptor, we can detect
ultraviolet rays using visible rays detection system.
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Detectable Wavelength
320-335 nm
Wavelength (nm)
20
透過率 %
200-240 nm
Transmissibility (%)
Relativity intensity
Arc light has various wavelength, though, there are special
wavelength ranges that has strong intensity.
So, we developed the interference filter that can transmit light of
200-240nm.
10
0
200
250
波長 [nm]
300
Wavelength (nm)
We adopted a fluorescent glasses
developed by Dr. Sawanobori [7].
Fluorescent glasses
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Angular Characteristic
Output ratio
The system has an output change with an angle deviation of light
incidence.
This result is the output ratio when light incidence deviates from
vertical line against acceptance surface.
When light goes straight to
acceptor, the output is 1.
But when the light deviates from
vertical line, the output become
a little small against vertical
line’s output.
Angle (degree)
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Output by Short Time Arc
Output voltage of
Output voltage of
the system
(V)
UVTA (V)
Voltage of between
Voltage of between
contacts (V)
electric
electric contacts(V)
This is whether the system can detect short time arc. We made an
arc generator to test it.
20
The test condition is 50V and 100 A.
15
10
This is the voltage of between
electrodes.
5
0
94 μsec
5
This is the output of the system.
4
3
2
The system can detect short time arc.
1
0
0
0
0.1
0.0001
0.2
0.0002
0.3
0.0003
0.4
0.0004
Time (sec)
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Verification Test
After tests of basic characteristics of the system, we verified the
system by two tests, laboratory and on-board test.
Rotating
disk
Pantograph
In laboratory verification,
We used the equipment
with rotating disk and
pantograph.
In on-board test,
We used a inspection car
in Shinkansen.
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Result of Verification Test
This is the result of on-board test. The test car has two pantographs.
The pantograph of car number 5 is taking large current while the
pantograph of car number 12 is losing contact.
Arc detector is detecting arc light until the current crosses zero.
Car No.5
Current
Car No.12
Current
Car No.5 Arc
detector
Car No.12
Arc detector
Time (s)
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User of This System in Asia
We tested the system step-by-step. Now, the users of the system is
gradually increase.
Shinkansen’s
inspection car
Low speed
railway’s
inspection car
High speed
railway’s test car
High speed
railway’s
inspection car
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Summary
 We developed contact-loss measuring system
using ultraviolet ray detection.
 In the system, although plastic optical fiber
can not transmit ultraviolet rays, we adopted it.
 We made a transformer that can transform
ultraviolet rays to visible rays.
 The systems were verified in some tests.
 Now, the system is being used in many railway
companies.
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Future Plan
We also research arc phenomena between contact wires and contact
strips. In the research, we are trying to solve the wearing mechanism
by arcing.
Arc trace of Contact wire
Arc trace of Contact strips
The amount of wear by arc are proportional
to energy between electrodes.
So, if we can measure the energy at a distance
from electrodes, we can estimate the amount of
wear. The system can measure energy of light.
We will show the relation between arc light
energy and amount of wear.
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Thank you for your attention
ご清聴ありがとうございます
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Rotation
disk
160μs
Detector
0.08 V
Light source
Rotating disk：1500rpm
0.04ms/div
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0.15,0.3, 0.6Ω
50 V
Contact wire
Contact strip
Thyrister
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