Solution for traction application

Modes of public transport such as high-speed trains, city transit systems and freight trains provide the ideal solution to meet the increased demand for more mobility whilst helping to fight pollution and traffic congestion. Power electronics is essential for driving and controlling energy in these systems.

For both electric or diesel trains, traction is provided by electric motors driven by inverters that rely on LEM transducers to measure, optimize and adjust the power sent to the motors, improving performance and reliability.


Main applications for Traction


Energy drive and control

LEM transducers provide control and protection signals to power converters and inverters that regulate energy both to the electric motors (for propulsion) and to the auxiliaries (for air-conditioning, heating, lighting, electrical doors, ventilators, etc).

Voltage networks vary from one country to another. LEM transducers monitor them closely to ensure power electronics work accordingly.

Global systems for propulsion of mining trucks are similar to the ones used for diesel-electric railway locomotives. Current sensors and voltage sensors enable inverter control which is essential for the efficient propulsion of trucks.

  • Main converter for urban transportation systems (metros - trams – trolleybuses),
  • Inverters, converters, rectifiers
  • Auxiliary power units
  • Circuit breaker, for transformers, DC link
  • Energy metering
  • Rolling stock heavy traction, diesel electric
  • Mining trucks

Products for traction

LEM traction application schema

DVC 1000-P


Certificates and standards

Compliance with the highest industry standards

LEM products and processes comply with reference standards in the industry:

• CE marking of LEM transducers in recognition of their electromagnetic compatibility

• EN standards for traction-based applications:
- EN 50155 for the electrical performances, environmental and safety constraints
- EN 50121-3-2 for EMC

• RoHS compliant

• ISO TS 16949 certification of all production and development centers (Switzerland and China)

• IRIS certification :
- Geneva Head Office since September 2007 (LEM Switzerland SA)
- Beijing production sites since 2008 (LEM Electronics China Co. Ltd)
- Sofia production site since 2016 (LEM Bulgaria EOOD)

Quality products and services: our priority

Based on our deep knowledge of applications and current measurement technologies, LEM develops both catalog and customized products which can be perfectly tailored to meet your needs in terms of performance, space requirement and cost.

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