Modes of public transport such as high-speed trains, city transit systems (metro, trams, trolleybuses…) and freight trains and also diesel electric locomotives provide the ideal solution to meet the increased demand for more mobility whilst helping to fight pollution and traffic congestion. Power electronics is essential to driving and controlling energy in these systems. LEM transducers provide control and protection signals to power converters and inverters that regulate energy to the electric motors (for propulsion) and to the auxiliaries (for air-conditioning, heating, lighting, electrical doors, ventilators etc). New requirements are continuously emerging in the railway industry, such as the demand for energy measurement, track objects monitoring and a need to constantly improve maintenance infrastructures.

Key Features

  • Isolated current and voltage measurement with instantaneous current or voltage output.
  • Non-contact or with integrated bus bar, or clip-on current measurement from 0.1 A to 20 000 A.
  • High voltage measurement from 10 V to 6,400 V.
  • High modularity offered in the various designs for a high level of mounting flexibility. Large options available for the possible secondary connections inspired by the railway market need.
  • High performances reached (accuracy from 0.2% to 2.7%, short response time from few ns to several μs).
Type Current Range Technology Power Supply Output Accuracy TA
LTC Series 350 - 1000 A Closed Loop ±15...24V 100...200mA 0.3% -40...+85°C
LF Series 100 - 2000 A Closed Loop ±12...24V 100...200mA 0.2...0.4% -40...+85°C
DVL Series 50 - 2000 A IDS ±15...24V 50mA 0.5% -40...+85°C
DV Series 1000-4200 V IDS ±15...±24V 50mA 0.3% -40...+85°C

IDS - Insulting Digital Technology

IDS - Insulting Digital Technology

Typical applications of LEM products:

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

A complete range of accurate, reliable and galvanically-isolated transducers for the measurement of current from 0.1A to 20,000A and voltage from 10V to 6,400V provides control and protection signals on-board as well as for trackside applications.

Global systems for propulsion of the mining trucks are quite similar to the ones used for diesel-electric railway locomotives. Inverter control is the key for the suiting trucks propulsion. Current and voltage transducers are accountable for the right control.

LEM transducers are CE marked in recognition of their electromagnetic compatibility and their compliance to EMC standards. Their reference standard is EN 50155 for the electrical performance and environmental constraints as well as EN 50124-1 for creepage and clearance distances design versus the required insulation levels.

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