Founded in 1950 to design and manufacture power converters for electrochemical applications, in 1974 FRIEM started producing rectifier units for railway, metro and tram lines.

Complete rail power-conversion systems

FRIEM is able to provide complete power conversion systems, including MV switchgears, special transformers, power converters, high-current DC isolators, and power-factor improvement and harmonic filter systems.

High-power converters

Thanks to continual investment in research and development, FRIEM is a world leader in the design and manufacture of high-power converters (diodes, thyristors or IGBTs) equipped with the most advanced digital regulations and protections.

Traction rectifiers

FRIEM’s traction rectifiers fully comply with IEC or ANSI/IEEE standards and the most stringent standards for heavy traction service.

FRIEM designs compact and modern rectifiers that provide an extremely high level of efficiency and reliability. The service continuity required by the rectifiers for traction applications led FRIEM to focus on the “redundancy” of main components, considering the application of semiconductors’ N-1 design as standard.

Easy-maintenance traction rectifiers

In accordance with the request for easy-maintenance traction rectifiers, FRIEM has developed a complete line of rectifier units with a fully withdrawable power section.

Control system for traction rectifiers

The standardisation of PLCs in FRIEM’s design has made protection and control equipment extremely flexible and capable of being installed locally, in a separate section of the rectifier cubicle, or remotely.

Our traction rectifiers meet all necessary safety standards: all materials inside the rectifier are flameproof and do not emit dangerous gases in the case of fire.

High-efficiency traction rectifiers

FRIEM’s unique design for its traction rectifiers’ power sections (involving semiconductors’ heat-sink and current conductors), means our rectifiers offer:

  • High efficiency, thanks to the reduced losses
  • High withstand capacity for short-circuiting, thanks to a robust structure
  • Production continuity and long operational life, achieved through a low operating temperature
  • Reliability and reduced maintenance

Traction rectifier operating characteristics

The operating characteristics of our traction rectifiers are as follows:

  • Connection: bridge / double bridge (series or parallel)
  • Type: diode, thyristor or IGBT
  • Cooling: natural air, forced air or water-to-air
  • DC output voltage: up to 3,300V
  • DC output current: up to 5,000A
  • Pulses: six or 12
  • Standards: IEC 60146 and ANSI/IEE

Traction rectifier design characteristics

The design characteristics of our traction rectifiers are as below:

  • Semiconductor (N-1) redundancy
  • Metal-enclosed fixed or withdrawable power section
  • Interphase reactor for 12-pulse double bridges in parallel
  • Up to NEMA4x (standard IP41) protection degree
  • High-accuracy metering systems
  • Automatic control combined with PLC and electronic boards
  • Transformer control
  • Local and/or remote control
  • Serial communication for interface with DCS (Modbus, Profibus DP, Ethernet, FMS or Datahighway Plus protocols)
  • Alarm and trip message history

Rail power converter installation, commissioning, start-up and maintenance

Thanks to its team of specialised technicians and a network of local service concessionaries, FRIEM can provide technical support for assistance, installation, commissioning and start-up all over the world.

When assistance is required, an immediate remote analysis of the problem often leads to an extremely fast and effective solution. Furthermore a quick and reliable on-site intervention can be guaranteed within 24 hours if there is an emergency.