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High speed: TGV POS prepares to enter service

01 Dec 2006

In readiness for the opening of TGV Est next June, Alstom is delivering multi-system TGV POS power cars equipped for operation in Germany and Switzerland. The latest addition to the TGV family features a powerful new transformer and regenerative braking. Laurent Charlier reports from Belfort

BY THE END of 2007, SNCF will have a fleet of 19 TGV POS (Paris - Ost Frankreich Süd Deutschland) trainsets based at the new Technicentre Est Européen at Pantin, operating over the first section of the high speed line between Paris and Strasbourg as far as Baudrecourt.

Each set will be formed of eight refurbished TGV Réseau trailers (RG 11.05 p685), marshalled between two TGV POS power cars of which Alstom Transport is supplying 38 for €233m under a contract signed on January 30 2003 and an option for eight additional power cars exercised in 2005.

The three-system power cars are equipped to operate at 25 kV 50 Hz in France and Luxembourg, at 15 kV 16 2/3 Hz in Germany and Switzerland and at 1·5 kV DC on conventional routes in western and southern France. The main challenge for the rolling stock engineers has been to meet the more demanding traction and braking performance required for operation at up to 320 km/h in France and 300 km/he_SFlbin Germany, while at the same time maintaining compatibility with earlier builds of TGV and ensuring that the number of changes are minimised to smooth the approvals process in each country where the new trains will operate.

These requirements have led to the TGV POS power car retaining the same mechanical structure and aerodynamic profile as its Thalys and Duplex predecessors, while some minor modifications to mechanical parts have been made such as adapting the reduction gear in the drive chain for 320 km/h and fitting electromagnetic track brakes for operation in Germany.

The only TGVs to operate in Germany under 15 kV to date are the four-system Thalys PBKA trainsets, equipped with synchronous traction motors and a GTO-based drive. TGV POS features a new drive with 3·3 kV IGBTs and asynchronous motors, the electrical equipment taking up less room but developing more power. The IGBT modules have been tried and tested in Alstom's BB 427000 and BB 437000 Prima freight locos for SNCF, with Palix modules supplying the traction motors and Cadix modules feeding auxiliary equipment. Reliability is enhanced by individual traction motor control, as a fault will lead to the loss of power from only one motor compared to the loss of two on previous TGV power cars where motors on the same bogie are controlled as a pair.

Compared to a Thalys trainset, limited to 250 km/h on high speed lines in Germany, the TGV POS is 5·5% more powerful under 25 kV but produces 84·8% more power under 15 kV (Table I). Weighing 10 tonnes, the transformer specially developed for TGV POS is rated at 4 830 kVA under 25 kV and 3 882 kVA under 15 kV.

Multi-system capability

Each TGV POS power car is equipped with two CX type pantographs, one with a bow 1 450 mm wide for 15 kV in Switzerland and 25 kV in France and Luxembourg. Specially developed for operating at up to 300 km/h in Germany, the second has two independent bows and would also be used under 1·5 kV DC in France. It was tested on the German high speed network in May and June 2006. The power cars are equipped for both rheostatic and regenerative braking, making POS the second member of the TGV family (after KTX for South Korea) to be able to return current to the overhead wire where conditions allow.

To operate at up to 160 km/h on conventional routes in Germany where the LZB train protection system has not been installed, electromagnetic track brakes are fitted on the rear bogie of each power car and the adjacent trailer bogie. As well as TVM 430 and ETCS Level 2, the trainsets are equipped with BRS and KVB for operation in France, the German Indusi/PZB and LZB signalling systems as well as Signum/Integra and ZUB for Switzerland. The Tornad train management system is fitted, enabling TGV POS to work in multiple with Réseau, Duplex and PBKA trainsets.

Testing of the first pre-series power cars took place between January 2003 and July 2004. A pre-series trainset was sent to the Velim test track in the Czech Republic before undertaking trials on the French network. Acceptance trials in Germany began in the spring of 2006, followed in August by testing in Switzerland and Luxembourg. With the first series-built power cars delivered at the end of July, the first series trainset was due to take part in these trials lasting until October 2007.

SNCF should have 15 POS trainsets for the opening of the first section of TGV Est on June 10 2007, with the remaining four to be delivered by November next year. According to the provisional timetable, they will operate 14 return trips a week between Paris and Stuttgart, as well as 19 return trips to Basel or Zürich. From winter 2007 they will also run to München. DB will operate 15 return services a week between Frankfurt and Paris with ICE3M trainsets.

The TGV POS power cars represent the latest stage in high speed rolling stock development by Alstom. With its AGV concept, Alstom is pushing the concept even further and is now at work on the next generation of high speed train which will carry 30% more passengers at up to 350 km/h. A seven-car prototype is due to emerge at the end of 2007.

  • CAPTION: The ETCS driver-machine interface screen is prominent in the centre of the cab display
  • CAPTION: A combined transformer has been developed to accept 25 kV 50 Hz and 15 kV 16 2/3 Hz power supplies
  • CAPTION: Fig 1. Tractive effort curves for a TGV POS set with half-worn wheels, operating on all three voltages. When running under 25 kV trainset is rated to achieve 320 km/h on level track with only six of its eight motors working
  • CAPTION: Fig 2. Dynamic braking performance TGV POS is able to regenerate on 25 kV and 15 kV overhead lines full rheostatic braking is provided for 1·5 kV DC operation and in the absence of line receptivity