Unveiled on 5 February at the Alstom Transport plant in La Rochelle (France), the AGV has just started its first dynamic tests on the speed track at the Velim Rail Test Centre in the Czech Republic. The test runs at up to 200 km/h, the maximum permitted speed at Velim, will finalize the development phase and validate Alstom's new very high-speed platform in the run-up to final approval.

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.