AGV

The **AGV** (acronym for French: *Automotrice à grande vitesse*) is a standard gauge, high-speed, electric multiple-unit train designed and built by Alstom.

Alstom offers the AGV in configurations from seven to fourteen carriages, seating 245 to 446 persons. The trains are constructed from units comprising three cars (each with one transformer and two traction electronics packages located underneath the cars) and single-car driver-trailers. The maximum commercial speed is 360 km/h.

Design of the train took place through the early 2000s, with a prototype, *"Pegase"*, produced in 2008. Italian transport company NTV ordered 25 trains in 2008 with service that began in 2012.

According to Alstom, the advantages of the AGV are: increased seating area per train length (compared to a single-deck TGV); safety and maintenance advantages of the Jacobs bogie articulation design as well as higher energy efficiency from permanent-magnet synchronous motors.

## History and design

The first design studies relating to the AGV were made in 1998.[3] An AGV design, initially named "TGV 400" was presented in Barcelona in early 2000 as part of Alstom's bid to supply high-speed trains for the Madrid–Barcelona high-speed rail line. Initial specifications were for a train with distributed traction (total power 7.2 MW), seating 359 in a train 180 metres long, with a version including eddy current brakes with a top speed of 350 km/h (220 mph), and a tilting version with a top speed of 320 km/h (200 mph). The design would retain the articulated Jacobs bogie of the TGV.[7]

Unlike the TGV, which was developed in collaboration between Alstom and SNCF, the AGV was developed wholly at Alstom's expense, with European Union rules on state aid limiting the extent of financial collaboration between the state-owned SNCF and Alstom.[8][9] The AGV was promoted in 2002 as a complementary high-speed train to the Duplex, offering higher speeds for less busy train paths,[8] while a double-decker AGV was posited as a future possibility by Alstom.[10]

The new design was the first high-speed train design in modern times that had inter-vehicle articulation and distributed traction.[n 5] The design used Alstom Onix IGBT based traction inverters; the weight reduction associated with IGBT technology allowed an axle load of within 17 tonnes per axle. The trainsets were to be made up of modules of 3-car sets with two powered bogies per module. Each motor bogie had two body-mounted self-ventilated motors, one per axle, rated at 600 kW. The traction electronics used two taps per transformer per module, each powering two parallel connected inverters, with a separate inverter for each motor. There were two carriage designs: the driving control cars, and intermediate cars; and two designs of bogie: powered and unpowered.[10][13]

The initial AGV design incorporated a number of new features: an electrically-activated active suspension (in the transverse direction to movement), used to limit oscillations between car and bogie; and eddy current brakes, fitted to the end bogies. Both technologies had been previously trialled on TGV sets. The carriages were constructed from aluminium alloy as used on the Duplex. The transformers, which weigh 6.5 tonnes, are fitted underneath the end cars, since the presence of the leading bogie allows the mass to be distributed over three instead of two axles. The interior structure was designed to allow easier refurbishment and alteration to the passenger environment. The floor level is kept practically constant throughout the train, including at inter-coach connections.[13][n 3]

By 2005, permanent-magnet synchronous motor technology had become mature enough to use in a commercial product, and was incorporated into the design allowing a bogie-mounted (instead of frame-mounted) traction motor, with higher efficiency and lower overall weight. The 2005 specifications allowed a wider (3 metre) carriage than the TGV, with a correspondingly shorter coach length. Alstom claimed operating and capital costs per seat were the same as a TGV Duplex.[3][9]

In 2007 a modified TGV Duplex, the 'V150', fitted with AGV-type bogies, traction electronics and traction motors (operating at 1 MW[1]) set a new rail speed record of 574.8 km/h (357.2 mph).[14]

The design was complete enough to be frozen by July 2006.[3] It had become formalised at basic train lengths of 7 or 14 cars, with the 3-car modules remaining part of the design. Each 3-car module had either a transformer or one of two traction modules (inverters) located beneath a carriage. Additional trailer vehicles (referred to as 'key' cars) were to extend the train size beyond multiples of three. The train is able to operate under all four European electrification systems, with a top speed specified at 360 km/h (220 mph) under 25 kV electrification, 320 km/h (200 mph) under 15 kV 16⅔ Hz supply, and further reduced to 250 km/h (160 mph) and 200 km/h (120 mph) under 3 kV and 1.5 kV respectively.[1]

The bogies are related to the type used on the TGV trains; in addition to the changes to traction motor type and installation, the bogies are constructed of a high tensile steel, for lighter weight, the bogie wheelbase is 3m as with the TGV. Braking is by rheostatic braking and regenerative braking, in addition to triple disc brakes on trailer bogies for low speed braking. An eddy current brake was not fitted.[1] The train also incorporates a carbon composite as a structural element, forming a U beam which supports the carriage body end on the secondary suspension.[3][n 1]

In January 2008 NTV (Italy) ordered twenty-five eleven-car trains for €650 million for use on the Italian rail network.[15]

The prototype *Pégase* AGV was unveiled in February 2008,[6] by which time Alstom had invested approximately €100 million in the development program.[3]

### Prototypes[edit]

By May 2000 prototype vehicles were being constructed for testing in 2001. Two coaches were constructed; a driving and an intermediate cab, with both trailer and motor bogies; for testing the units were attached to a four car TGV Reseau set.[13] The test train (named "Elisa"[16]) began tests in late 2001; including ride and noise level measurements, as well as testing of a multisystem "Europantograph", designed to work with all four European overhead electrification systems. Dynamic tests included measuring traction motor, braking rheostat, transformer and inverter cooling under high-speed conditions, as well as aerodynamic tests on airconditioning system performance at high speed.[10] Initial tests were complete in May 2002.[8]

By 2004, enabled by the availability of rare-earth magnets with high magnetic strength, Alstom had developed permanent-magnet synchronous motors (PMSM) which were suitable for rail vehicles. They were smaller and had a higher efficiency than asynchronous motors and a higher power-to-weight ratio, as well as having the potential for lower noise levels. The AGV was one of the early applications of the new motor design, using 720 kW prototype motors weighing 730 kg.[5][17] By 2008 the motor's continuous power rating had been respecified to 760 kW.[2][3]

In late 2005 Alstom began the process of constructing a 7-car AGV demonstration train fitted with PMSMs, with half the bogies powered.[9] The demonstration vehicle, named *Pégase* (*Prototype Evolutif Grande vitesse Automotrice Standard Européen*) was assembled at Alstom's La Rochelle plant, with bogies built at Alstom's Le Creusot plant.[18] The prototype was unveiled on 5 February 2008, at La Rochelle, in the presence of president Nicolas Sarkozy.[3][6]

The transformers were mounted in the driving cars, with the other two cars of the three car modules each carrying a traction converter (ONIX 233 water cooled), which also integrate auxiliary converters, the middle 'key' car carried auxiliary equipment under the carriage. The HVAC equipment is mounted on the roof. The internal DC inverter power bus is supplied at 3600 V DC.[2][4]

The unit began a four-month dynamic testing programme at speeds up to 210 km/h on the Velim railway test circuit in the Czech Republic in mid-2008.[19]

Testing over four weekends on the LGV Est high-speed line began in late 2008; the train completed 7500 km of test runs, after which it returned to the Velim test track for tests relating to certification for NTV's trainsets in Italy, including SCMT safety system integration.[20]

In 2010 the AGV test train began testing in Italy, reaching 300 km/h (190 mph) on the Rome-Naples high-speed line. Dynamic tests were completed by March 2010.[21]

## Avelia

In 2008 the President of Alstom Transport, Philippe Mellier, stated that an 'AGV Duplex' would be developed, and would become Alstom's double deck train offer (for SNCF) after the TGV 2N2.[31] In June 2011 Les Échos reported that Alstom was developing a new high speed train, "AGV II" with a top speed of between 380 and 400 km/h (240 and 250 mph), to be available as a single and a double deck version. The design was to utilise power/traction equipment in a single unit (locomotive) as previously used in the TGV design, rather than distributed traction.[32] The traction locomotive design was thought to be aimed in part at orders from SNCF as early as 2014/5 or post 2015.[32][33]

In 2015 Alstom and ADEME (*Agence de l'environnement et de la maîtrise de l'énergie*) formed a joint venture, 'SpeedInnov', with the aim of developing the next generation high speed train for France.[34]

In October 2015 the technology was grouped into the series of *Avelia* branded products for Alstom's high-speed trains, consisting of the existing Pendolino, Euroduplex and AGV offers.[35] At that time NTV bought 8 Pendolino high-speed trains with the *Avelia Pendolino* having a maximum speed of 250 km/h.[35] In August 2016 Amtrak and Alstom announced that the Avelia Liberty trainset had been chosen to replace the existing Bombardier-Alstom Acela Express trainsets on the Northeast Corridor between Boston and Washington, D.C. via New York City and Philadelphia.[36][37] The Avelia Liberty will combine Pendolino active tilting at a speed up to 300 km/h and it can reach a maximum speed of 350 km/h without tilting like the AGV basis.

The cooperation with the SNCF led into a contract for 100 Avelia Horizon double deck trains in August 2018.[38] These trains have a top speed of 350 kilometres per hour (220 mph) as well.