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LEM Solutions

LEM solutions for electrical measurements

This catalogue summarizes the most common LEM product offerings for industrial, railway, high accuracy, and automotive

measurements.

LEM is the market leader in providing innovative and high quality solutions for measuring electrical parameters. Its core products

- current and voltage transducers - are used in a broad range of applications including drives & welding, renewable energies &

power supplies, traction, high precision, conventional and green vehicle businesses.

With higher accuracy and speed, the feedback signal from LEM transducers enables smoother control and energy consumption

reduction of many electrical systems.

At the heart of … ELEVATORS

In most lifts installed worldwide, LEM transducers prevent the doors closing on passengers. They keep the cabin stable when

people enter, and ensure that the lift rides smoothly by adjusting the torque of the motor.

At the heart of … RENEWABLE ENERGIES

LEM transducers, specifically designed for renewable power systems, control the flow and waveform of energy sent to the grid

from photovoltaic and other renewable energy systems. They measure the current to help the windmills and solar installations to

work at their maximum efficiency.

At the heart of … TRACTION

Regardless of whether a train is powered by diesel or electricity, traction is provided by electric motors driven by inverters

that are relying on LEM transducers to measure, optimize and adjust the power that is sent to the motors, improving both

performance and reliability.

At the heart of … HIGH PRECISION APPLICATIONS

The quality of the image provided by MRI scanners is linked directly to the accuracy of the current measurement.

The current transducer used has a direct impact on the image and if the transducer is not precise enough this will lead to a

blurred and illegible image. LEM current transducers set a standard for accuracy and are the most precise industrial products

in the market today. The transducers provide levels of stability and precision, at about 1–3 parts per million, which makes them

references in calibration test benches or in laboratories.

At the heart of … AUTOMOTIVE

In electric and hybrid vehicles, LEM transducers monitor energy levels to and from the battery and are critical in the control of

the electric motors.

It is our business to support you with both standard and customized products to optimize your application.

DRIVES & WELDING MARKET

RENEWABLE ENERGIES & POWER SUPPLIES MARKETS

Today, the transducer market has two main technology drivers: first, the desire for a greater degree of comfort and finer

regulation, and second, the need to save energy. This means that more and more applications that used to be mechanical are

changing to fully electronic control which provides increased reliability, improved regulation and higher energy efficiency.

Today, about 15 % of all motors have an inverter control. This inverter can save 50 % of the total energy consumed, which is a

huge potential for savings.

The inverter control used in these newer systems requires reliable, accurate current measurement to enable engineers to

develop a system with isolated current measurement directly on the motor phases.

Energy savings is the key word today and this includes the exploitation of the wind and the sun as alternate energies. To use

these renewable sources, in the most profitable way in terms of energy efficiency, the use of power electronics is a must and is

essential to drive and control energy in industrial applications. Modern systems are becoming more complex and require precise

coordination between the power semiconductors, the system controller, mechanics, and the feedback sensors. Transducers

provide the necessary information from the load to fulfill that function. We can compare the use of transducers to adding “eyes”

to the system.

They can supply the “brain” of the system, in real time, with information regarding the condition of the controller.

LEM products are already used among a broad spectrum of power electronics applications such as industrial motor drives,

UPS, welding, robots, cranes, cable cars, ski lifts, elevators, ventilation, air-conditioning, power supplies for computer servers,

and telecom.

This trend towards more involved power electronics happens in a general manner in the industrial world, for example, in lighting,

domestic appliances, computers and telecom applications. Power electronics increases efficiency by delivering the correct type

of power at the most efficient voltage, current and frequency.

TRACTION & TRACKSIDE MARKET

Today, high speed trains, city transit systems (metro, trams, and trolleybuses) and freight trains are the solutions against

pollution and interstate traffic immobility, and provide a significant energy savings.

Power electronics is essential to drive and control energy in these transportation systems.

LEM has been the market leader in traction power electronics applications and development for the last 40 years and leverages

this vast experience to supply solutions for isolated current and voltage measurements.

LEM transducers provide control and protection 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, ventilation, etc.). This includes the

incoming monitoring of the voltage network (changing by crossing European borders) to make the power electronics work

accordingly.

Although this is true for on-board applications, LEM has also provided the same control and protection signals for wayside

substations.

The rail industry is under constant changes and evolution. As a recent example, the privatization of the rail networks raised

new requirements for which LEM provides: the onboard monitoring of power consumption (EM4T II Energy Meter), solutions to

trackside applications, rail maintenance and the monitoring of points (switches) machines or signaling conditions with some new

transducers families.

LEM is always available to assist in adapting to these evolving technical applications.

Four decades of railway experience have contributed to establishing LEM as the market leader with worldwide presence to serve

you and provide the efficient, safe and reliable operation of the railways.

HIGH PRECISION MARKET

Certain power-electronics applications require such high performance in accuracy, drift and/or response time that is necessary

to switch to other technologies to achieve these goals. The validation of customer equipment is made through recognized

laboratories using high-performance test benches supported by high-technology equipment including extremely accurate

current transducers. These transducers are still in need today for such traditional applications but are more and more in demand

in high-performance industrial applications, specifically medical equipment (scanners, MRI, etc.), precision motor controllers,

and metering or accessories for measuring and test equipment. LEM has been the leader for years in producing transducers

with high performance and competitive costs for these markets. The 2009 acquisition of the Danish company, Danfysik ACP

A/S, as being the world’s leader in the development and manufacturing of very-high precision current transducers, reinforced

this position.

To achieve this challenging target of accuracy and performance, LEM’s current transducers for the high precision market use an

established and proven technology, the Fluxgate technology deployed in different alternatives.

Thanks to this technology, we can claim accuracies in the parts per million (PPMs) of the nominal magnitude and is

representative of the performance achieved.

The high-accuracy product range covers transducers for nominal current measurements from 12.5 A to 24 kA while providing

overall accuracies at ambient temperatures (25°C) of only a few PPM. Thermal offset drifts are extremely low, only a few PPM

per Kelvin (K).