Trafomec Transport Systems applications

Trafomec designs and manufactures Traction Transformers and Electromagnetic Assembly for all types of transport, railway and marine applications, supported by a wealth of experience in the industry proven internationally by a long track record.

Trafomec tailor-made products meet the challenges posed by the physical and operating constraints of the transport, railway and marine environments, meeting the highest customer technical and service requirements.

Main applications for Transport Systems

The TSA (Transport Systems Applications) division in specialized in the design and manufacture of traction transformers and electromagnetic assembly for all types of transport, railway and marine applications.

  • Traction & Propulsion transformers: impregnated, air cooled low/medium voltage transformers and reactors installed on rotary material
  • Traction & Propulsion reactors: incorporated or impregnated, air cooled low/medium voltage reactors for stationary railway
  • Oil cooled reactors: impregnated, oil cooled medium voltage transformers for medium voltage converters installed in rotary material

Railway “on board” system:

  • Filtering DC current from superposed harmonics (Line filter reactors)
  • Filtering AC currents in order to have the right shaped current for the final load (Filter reactors)
  • Others

Railway installation:

  • Filtering DC current from the line (Substation filter reactors)
  • Filtering disturb on the signaling (Rail path reactors – impedance bound)
  • Others

Concentric Air Core reactor

Concentric-Type Air Core reactors

Components used for filtering, di/dt limitation natural or forced switching. The harmonic contents of the current or the need to achieve a high quality factor could requires the use of medium-frequency multitstrand (LITZE) conductors.


Technical information

Nominal value and frequency spectrum as per technical specifications with wide range of solutions. In case of important multistrand internal manufacture of LITZE conductors is also possible

Toroidal Air Core Reactor

Toroidal Air Core Reactors

Toroid coils are suitable alternative to concentric-type coils whenever a low dispersion of flux in air is required.

Nominal Inductance 10 μH Insulation class H
Tolerance -0% +10% Cooling System Forced Air Cooling
Fundamental Current 850A @ 50Hz Ambient Temperature 70°C
Ripple Frequency 300 Hz Protection index IP00
Peak Current 1050 A Dimensions 620x550x140 mm
Operating Voltage 1900 Vpk-pk Weight 36 kg
Rod-type straight core reactor

Reactors with straight Core (Rod-Type)

Reactors used for smoothing or filtering DC currents; preferred to air-type chokes for their smaller size.
Holding sufficiently high residual inductance values even in short circuit conditions

Nominal Inductance 4.7 μH BIL 6 kV
Tolerance -0% +10% Cooling System Forced Air Cooling
Fundamental Current 560A @ 50Hz Ambient Temperature 40°C
Ripple Frequency 60 Hz Protection index IP00
Insulation Class H Dimensions 650x640x660 mm
Nominal Voltage 1500 V Weight 675 kg
Closed core reactor

Reactors with closed Core

Suitable for filtering or smoothing reactors whenever no strict requirements on the linearity for low current values are given. Unlike Rod-Type units, these coils show a very low stray flux.

Nominal Inductance 6.2 μH Losses at 115°C 5500 W
Tolerance -0% +10% No load losses 500 W
Fundamental Current 245A @ 50Hz Cooling System Forced Air Cooling
Insulation class H Ambient temperature 50°C
Nominal Voltage 2400 V Protection index IP00
BIL 6.9 kV Dimensions 490x490x330 mm
Weight 130 kg
Single or three-phase matching transformer

Single or Three-phase Matching Transformers

Matching transformers whose electrical parameters are often very specific (rectangular-shaped voltages, intermittent operation, currents with high harmonic content) are used at the output of converters for auxiliary services.

Voltage Low voltage to low voltage Spectrum Wide frequency
Insulation class H Cooling System Forced Air Cooling
Ambient temperature 75°C Protection index IP00
Weight 100 to 1000 kg
Railway transformer with integrated choke

Railway Transformers

On railway to feed auxiliary services it is necessary to use large transformers. Also available with integrated choke (two components in one).

Primary voltage 800 V Insulation class H
Secondary voltage 480 V Protection index IP05
Primary Current 730 A Temperature 40°C
Secondary Current 1148 A Losses at 115°C 16100 W
Connection Dyn11 Dimensions 960x990x640 mm
Frequency 60 Hz Weight 1660 kg
Isolation voltage 3.2 / 6.75 kV
Line filtering inductor for direct current locomotives

Line Filtering Inductors for DC locomotives

These inductors are mounted on board of Direct Current locomotives. They are intended to reduce the harmonic content of the line current and to limit transients and surges. The construction most commonly encountered is the “straight rod” type with a magnetic shield to catch the stray-flux and meet the EMC requirements.

Nominal inductance 7-21.5 μH Cooling system Forced air cooling
Tolerance 10% Ambient temperature 55°C
Fundamental Current 2300 A Protection index IP00
Insulation class H Air Flow 2 m³/sec
Isolation voltage 22 kV Dimensions 900x1130x980 mm
Losses 120 kW Weight 2400 kg
Line filtering inductor

Line filtering Inductors

These inductors are mounted in series with the traction motor in order to reduce the ripple current and to limit the possible fault currents. These applications require the use of air or straight rod types, the flux being generally captured by a shield.
These reactors are usually built in pairs corresponding to the two traction motors mounted on the same axle of the locomotive.


Technical information

The mechanical aspect is the main issue for this component and Trafomec's technical division has the possibility to shape the iron profiles according to the needs.

Air core inductor with shielded reactor

Air Core inductors with Frame (Shielded reactors)

These components are often used as intermediate circuit chokes in chopper-based power systems. The proposed design puts together the advantages of the air core and the iron core constructions: high residual inductance (good linearity) and low stray flux.

Nominal inductance 12.8 μH Short circuit current 13 kA
Tolerance -0% 10% Losses 22.1 kW
Fundamental Current 670 A Cooling system Forced air cooling
Frequency 300 Hz Ambient Temperature 55°C
Insulation Class H Protection index IP04
Nominal Voltage 1.9 kV Dimensions 400x850x850 mm
Isolation Voltage 7 kV Weight 970 kg
Component with fully insulated Winding

Components with fully insulated Winding

When the presence of water, humidity or condensation cause a deterioration in the insulation of active parts (which are ensured by superficial distances), the windings are manufactured using specially insulated conductors, in order to withstand the full testing voltage.

Nominal inductance 7-21.5 μH Ambient Temperature 55°C
Tolerance -0% 10% Protection index IP00
Fundamental Current 2300 A Air Flow 2 m³/sec
Insulation class H Dimensions 900x1130x980 mm
Isolation Voltage 22 kV Weight 2400 kg
Losses 120 kW
Filtering Choke for Railway Substations

Filtering Chokes for Railway Substations

Downstream to the rectifying installations for railway lines, large DC filtering systems have to reduce all perturbations originating from the rectifiers to prevent interferences with the signaling frequencies in the line; high power reactors are used for this purpose. Working together with Railway Engineers, TRAFOMEC has led the competition with a specific project of air core reactor with aluminum foil winding.

Nominal inductance 6 μH Insulation Class F
DC current 3000 A Protection index IP00
Ripple current Negligible Cooling system Natural air cooling
Fault Current 40 kA Dimensions 1800x1800x1500 mm
Operating Voltage 3000 Vdc Weight at least 3000 kg
DC filtering inductor

DC filtering inductors

This component mounted under frame has been properly working for several years in railway applications in France.

Nominal inductance 9.5 μH case IP20
DC current 900 A Cooling system Natural air cooling
Ripple current 285 A Rate of Flow 0.7 m³/sec
Fault Current 40 kA Pressure drop Δp 150 Pa
Operating Voltage 2000 Vdc Speed 5.6 m/s
Insulation Class H Dimensions 1890x1100x580 mm
Protection index Inductor IP05 Weight 1500 kg
Inductive Connections for Rails and Substations

Inductive Connections for Rails and Substations

Special reactors located between the railway tracks are installed at the end of each section of track, or at each railway substation. These devices, characterized by a mid-winding tap, allow the flow of line current between adjacent sections of tracks or between one section of tracks and the substation. These reactors guarantee the proper operation of power and reception circuits of encoded signals even in the presence of unbalanced line currents between one track and the other. Magnetic components are housed in a fully enclosed cabinet (IP 54) with cooling fins. A special resin guarantees the complete protection of active parts and optimal heat dissipation.

Current 300 A Dimensions 300x555x275 mm Weight 110 kg
Current 500 A Dimensions 370x640x365 mm Weight 220 kg
Current 750 A Dimensions 580x750x540 mm Weight 560 kg
Current 1000 A Dimensions 660x750x690 mm Weight 960 kg
Three-phase air core reactor in railway traction power converters

Three-phase air core reactor for di/dt limitation in railway traction power converters

On traction converters sometimes it is necessary to limit very quick transient of current. With this solution Trafomec has been able to provide the right equipment.

Nominal inductance 25 μH ± 5% Protection index Inductor IP04
DC current 280 A Cooling system Forced air cooling
Fault current 11 kA peak Speed 3 m/sec
Operating Voltage 2000 Vpk-pk Dimensions 260x530x185 mm
Insulation Class H Weight 18 kg
Roof mounted DC Filtering Inductor For Railway Traction

DC Filtering Inductor For Railway Traction (hot weather)

This solution, mounted on top of a train in Australia is exposed to sun-rays, but with the help of a special paint we prevent the risks of UV-rays ageing effects.

Nominal inductance 15 μH Protection index Inductor IP05
DC current 560 A Cooling system Forced air cooling
Linearity 15 μH @ 800 A Rate of Flow 0.7 m³/sec
Ripple current 15 A Pressure drop Δp 150 Pa
Ripple frequency 300 Hz Speed 5.6 m/s
Fault current 6 kA peak Dimensions 860x990x670 mm
Operating voltage 1500 Vdc Weight 1075 kg
Insulation class H
Snowstorm resistant DC Filtering Inductor For Railway Traction

DC Filtering Inductor For Railway Traction (cold weather)

The component mounted on the top of railway coaches is protected with a special epoxy-glass panel. This solution offers protection not just from UV rays, but also from major snow storms and heavy rain.

Nominal inductance 4.7 μH Protection index Inductor IP04
DC current 560 A Cooling system Forced air cooling
Linearity 3.75 μH @ 1100 A Speed 2.7 m/sec
Ripple current 56 A Weight 675 kg
Operating voltage 1500 Vdc Dimensions 650x835x630 mm
DC Filtering Inductor For Railway Traction under-frame

DC Filtering Inductor For Railway Traction (under-frame)

The component is mounted under-frame in railway coaches, using forced cooling; the complete equipment is delivered ready to be mounted.

Nominal inductance 9.5 μH Protection index Inductor IP20
DC current 1100 A Cooling system Forced air cooling
Ripple current 285/10 A Rate of Flow 1 m³/sec
Ripple frequency 100/600 Hz Dimensions 1110x2155x760 mm
Operating voltage 1800 Vdc max Weight 1750 kg
Insulation class H
Single-phase output transformer with built-in reactors

Single-phase output transformer with built-in reactors for auxiliary services

Another important technical solution used by Trafomec: to provide complete waterproofness of these components, a special sealing compound is added on the top and bottom of our coils.

Power rating 85 kVA Protection index Inductor IP04
Primary voltage 1000 V Cooling system Forced air cooling
Secondary voltage 345 V Rate of Flow 500 l/sec
Frequency 50 Hz Pressure drop Δp < 200 Pa
Sh. C. impedance 22% Dimensions 450x380x430 mm
Ambient Temperature 60°C Weight 235 kg
Insulation class H
DC filtering inductor for railway traction converters of light railway vehicles

DC filtering inductor for railway traction converters of light railway vehicles

In Singapore the problem was a reduced stray flux but the engineers at Trafomec provided the solution using a partial screen against the magnetic flux.

Nominal inductance 2.5 μH Protection index Inductor IP05
DC current 205 A Enclosure IP20
Linearity 2.5 μH @ 312 A Cooling system Natural air cooling
Fault current 15 kA peak Mounting Under frame
Operating voltage 1500 V Dimensions 580x580x430 mm
Insulation class H Weight 125 kg
Railway filter for auxiliary services

Railway filters for Auxiliary Services

In China these components mounted under-frame need to be protected against ballast and rocks coming from the railway path. This is our solution: a very compact case IP20 with special paint.

Nominal inductance 5 μH Cooling system Natural air cooling
tolerance ± 5% Ambient temperature 40°C
Fundamental current 900 A Protection index IP24
Insulation class H Dimensions 610x830x480 mm
Isolation voltage 6 kV Weight 420 kg
Nominal voltage 1.8 kV
Small filter for railways

Small Filters On Railway

This component is after mounted in a small filter with capacitors in order to have a right current shape for the customer assembly.

Nominal inductance 0.28 μH Frequency 6 kHz - 10 A
tolerance -0% +10% Ambient temperature 40°C
Fundamental current 130 A Protection index IP00
Insulation class H Dimensions 370x200x350 mm
Isolation voltage 2.5 kV Weight 44 kg
Nominal voltage 1.8 kV
Download TSA brochure