The Traction Department at JST Transformateurs designs and manufactures a complete range of :

• Traction Transformers :
  • Mono- or multi-system, mono or bi-frequency : AC (25/15kV), AC/DC(3/1.5kV), 16.67 Hz, 50 Hz or 60 Hz;
  • Rating up to 10 MVA (no technological limitations);

  and/or,

• Winding/Traction inductors :
  • Filtration;
  • Smoothing.

Example of a transformer (on crate) EMU

For all types of trains: High-speed trains (TGV), Locomotives, Rail motor vehicles (Electrical Multiple Unit), Regional trains, and Subways. These transformer-inductors are designed for box mounting, under the floorboards or on the roof. They often integrate refrigeration and have been developed in close collaboration with a partner to be adapted to a train to provide a “Plug and Play” type of solution.

In 50 years, JST Transformateurs has delivered more than 3,000 traction transformers all around the world (Europe, USA, India, etc.)

We use shell technology for traction transformers and inductors since they provide the following advantages :

• Reduced mass: A very compact transformer with reduced oil volume;
• Natural resistance to short-circuits, vibrations, and mechanical impact: Stress transmitted to the tank;
• Uniform cooling of the winding: uniform oil flow;
• Flexibility in dimensions : all 3 dimensions of the active part can be fixed independantly one from eachother;
• Decoupling between secondary windings: no electrical influence between windings;
• Electromagnetic compatibility (EMC): no field radiated outside the tank; and,
• High reliability: The result of 50 years of return of experience.

• JST Transformateurs is the exclusive designer of successive generations of the main transformers used in French high-speed trains (TGV) for the SNCF: TGV PSE/TGV A/TGV R/TGV Duplex synchronous/TGV Duplex asynchronous.
• Reduction of mass and volume allocated to the transformer by using :
  • Aluminium tanks (20 years return of experience);
  • High thermal class : H and hybrid;
  • Cobalt magnetic circuitry.
• Modernization or increase in power of existing trains :
  • Our shell-type technology can meet the need for an increase in power or for the modernization of a traction chain when the new transformer must remain within the pre-existing volume and mass. Application: Modernization of a traction chain. Revamping of a rail motor vehicle transformer for Metro-North USA (13x2000 kVA in 1993, and then a second series of 48 units).
• Technology suited to the rising needs of the market :
  • Development of the multi-system transformer market in Europe : the application of our new development allows drastic weight reduction (see above);
  • Shell technology is the solution for the requirements of traction chains using a high number of secondary windings (6, 8, 10), particularly those with an odd numbers of windings with very strict decoupling requirements.