The latest member of the Alstom very high-speed train
family - the AGV - undergoes its first dynamic tests

No less than fifteen engineers from various Alstom Transport
manufacturing sites will take it in turn to perform tests on
the AGV prototype until September 2008. The AGV will travel
nearly 60,000 km fitted with over two thousand sensors during
the four months of tests. The measurements and data compiled
will be transmitted and analyzed by the Alstom engineering
departments, which will suggest the necessary adjustments and
modifications for the train to be validated.



In 2003 Alstom decided to anticipate market needs with the
launch of a fourth-generation very high-speed train. The new
train was designed to meet a specific challenge: to provide a
one-level range of trains to complete its , with higher
performance levels and reliability along with controlled costs
and thus offer operators a concrete advantage in terms of
safety, comfort, environmental protection and controlled
running costs. Alstom has drawn on over thirty years experience
in very high-speed applications to design and develop the
train, opting for a radically new approach in the railway
industry: financing the AGV entirely from its own resources,
without fixed customer specifications. It quickly proved
essential to produce a prototype for use in "actual size"
checks of the simulations and computer modelling produced by
engineering departments and design offices. The 7-car prototype
serves as a real laboratory on wheels, and is now configured
entirely for the needs of the dynamic test campaign being
conducted at Velim. Only two cars are fitted with seats, with
the five other cars entirely fitted out for test purposes: the
first two provide a work station for the engineers, the third
houses the generator supplying electricity to the measuring
instruments, the fourth acts as a spare parts store for the
train and the fifth is the living area.



In line with the Alstom Transport industrial plan, the
components used in the first AGV have been designed and
developed at the company's various Centres of Excellence:
Tarbes for the traction drive, Le Creusot for the bogies,
Villeurbanne for the control electronics, Ornans for the
traction motors and La Rochelle for the body structure and the
trainset layout. This was also the logic behind the first crash
tests in Reischoffen and the first climatic chamber
measurements in La Rochelle. The test programme was launched in
La Rochelle with a series of static and low-speed measurements
and validations after assembly and production of the trainset.
Only the main functions, like the traction drive steering, the
pantograph raising and lowering controls, and the door opening
and closing, were checked under two voltages (25 kV and 3000
V). A few additional checks, such as managing the main circuit
breaker and commissioning batteries and auxiliary voltage
selectors, were also made when the train first began running,
at up to 40 km/h.


A very high-speed validation programme

The Velim Rail Test Centre speed track is 13 km long and is one
of only a handful worldwide where trains are permitted to
travel at 200 km/h. With a Czech driver trained in La Rochelle
at the controls, the AGV will be subject to a lengthy test
programme until September, firstly at reduced speed then at
gradually increasing speeds of up to 200 km/h. Although these
tests are being performed at a lower speed than the AGV's
design speed (360 km/h in commercial operation), they
nevertheless provide a very accurate picture of the dynamic
behaviour of both the train and most of its components.



The measurements carried out by the Alstom engineers will focus
on the wheel-rail dynamics, i.e. the quality of the contact
between these two elements. Extremely difficult to model using
computers, these tests involve checking the vibration level
perceived by the passengers by placing sensors on the bogies
and inside the trainset. For the AGV, the first very high-speed
train entirely made up of articulated cars, this also involves
checking the dynamic behaviour of the trainset.



The Alstom engineers will also be examining the
pantograph-catenary pairing. Installed at the first passageway
between cars, the pantograph is particularly vulnerable to
disturbance caused by the train nose. Roof-mounted cameras will
film the force produced by the pantograph on the catenary at
various speeds and its ability to collect the current. In
particular, the number and duration of electric arcs will
provide the experts with information on the adjustments to be
made. The pressure of the pantograph on the catenary can be
adjusted continuously with a fully-operated system.



The AGV's innovative new synchronous permanent magnetic motors
carry the latest developments in power electronics, allowing
them to operate under the four types of electric voltage found
in Europe: 1500, 3000, 15000 volts and, more widely used in the
rest of the world, 25000 volts. Very precise development is
necessary for these motors and the traction drive motor to
operate under these voltages. Their operation is monitored to
control wheelslip during start up and locking of wheels when
braking. Electronic systems regulate the physical phenomena as
they do in modern automobiles.



All the train's functional elements are validated dynamically
at Velim, following the same programme as the static tests in
La Rochelle. This involves testing over a hundred functions
controlled from the driver's cab with the train operating
normally and in degraded mode: controlling pantographs, voltage
selections, inside and outside lighting, air-conditioning and
circuit breaker closure. These tests will also be used to check
that the procedure for feeding information back to the driver
should an item of train equipment malfunction is satisfactory.


The AGV braking system is one of its most complex elements. Its
dimensioning is also an essential safety factor which is very
precisely regulated. It is therefore tested under extreme
conditions, in emergency situations, in normal and degraded
mode, under normal and reduced adhesion conditions, all at a
variety of speeds between 30 km/h and 200 km/h. One test causes
the train to brake on a section of rail made slippery with
soapy water, simulating phenomena such as the presence of
leaves on the track. Measuring the train's stopping distances
will identify necessary adjustments. One reason for the
complexity of the AGV braking system is the fact that it
combines a rheostatic brake with a regenerative brake. Any
power generated by the motors during braking not consumed by
the train can be sent to the national grid. This system, which
requires numerous adjustments, will also be validated at Velim.


AGV is a means of transport in line with sustainable
development requirements, producing very low greenhouse gas
emissions. It emits a mere 2.2 g/km/passenger, i.e. thirteen
times less than a bus (30 g), 50 g less than an automobile (115
g) and seventy times less than a airplane (153 g) . Although
the aerodynamic drag, one of the train components with the
highest consumption, can be simulated fairly accurately in a
wind tunnel, it is important nevertheless to check its
conformity under actual conditions. The Alstom engineers will
check the aerodynamic coefficient (Cx) of the AGV.



Reduced sound nuisance was another environmental aspect the
Alstom engineers focused on when designing the AGV, with the
aim of maintaining the acoustic comfort at 360 km/h at the same
level as that of its competitors at 300 or 320 km/h. The
acoustic tests at Velim will involve arranging microphones, in
accordance with the standards in force, the length of the test
track to measure the noise emitted as the train passes.
Reducing aerodynamic and train movement noise has also been
studied meticulously with the aim of ensuring the comfort of
passengers and drivers alike. Microphones installed at
different heights in the cab, the cars and the passageways
between cars can simulate seated or standing passenger noise
perception.



Following the dynamic test campaign at Velim, the AGV will
embark on new test sessions in France taking it to its maximum
commercial speed of 360 km/h. During 2009 it will also travel
on the Italian rail network as part of the approval process for
delivering trainsets ordered by NTV . The new Italian transport
company has placed a firm order for 25 trainsets (with ten on
option), together with a thirty-year maintenance contract.
Delivery of the first production trains will commence in 2010.



About Alstom Transport

With the focus on sustainable transport, Alstom Transport
develops and offers the most complete range of systems,
equipment and services on the rail market. Alstom Transport is
capable of managing an entire transport system, from rolling
stock to signalling and infrastructure, as well as offering
turnkey solutions. Alstom Transport recorded a 39% increase in
orders for the 2007-2008 financial year, with turnover up 4%
compared with the previous year.


Press contact

Laurent Gerbet - Tel. + 33 1 41 66 92 83


laurent.gerbet@transport.alstom.com


Internet site:

www.transport.alstom.com