Application of LEM transducers in automation and power electronics

Thanks to LEM transducers, it is possible to accurately monitor current and voltage in various energy applications and automation systems, making them indispensable in modern technology. Their popularity stems from high accuracy, reliability, and resistance to electromagnetic interference, which is common in industrial environments. In both direct current (DC) and alternating current (AC) systems, a current transducer allows for energy flow monitoring, system management, and protection of electronic devices.

Operating principle of LEM transducers

LEM transducers operate based on two main current measurement methods:

Hall sensors

They generate a signal proportional to the flowing current based on the magnetic field produced by the conductor. This method allows measurement of both direct current (DC) and alternating current (AC) with galvanic isolation between the measured circuit and the output electronics.

Inductive (transformer) method

It uses the phenomenon of electromagnetic induction and works exclusively for alternating current (AC).

Thanks to these technologies, it is possible to generate an output signal proportional to the flowing current without direct electrical contact with the high-voltage system. This increases work safety and minimizes the risk of component damage in case of overvoltage or system failure.

Construction of LEM transducers

A typical LEM current transducer consists of:

• Current conductor – through which the measured current flows.
• Hall sensor or inductive system – responsible for detecting the magnetic flux.
• Output signal converter – converting the signal into a proportional current or voltage.

Galvanic isolation ensures safety and protects measurement electronics from damage in case of overvoltage.

Types of LEM transducers

A wide range of LEM transducers is available on the market, adapted to various industrial and power electronics applications:

• DC current transducers – monitoring and controlling direct current in power supplies, energy storage systems, and electromobility.
• AC current transducers – used in electric machines, inverters, photovoltaic, and wind systems.
• High-current transducers – up to 1000 A, and even 500 kA in large industrial and energy installations.
• Isolated and shunt transducers – isolated types provide full galvanic separation, while shunts use resistance to measure current, without isolation (for specialized applications).

All types allow real-time current monitoring and generating a signal proportional to the measured value, which is crucial for control and protection of automation and power electronics systems.

Application of LEM transducers in automation

In automation systems, LEM transducers enable precise current measurement in machine and industrial equipment control circuits. They make it possible to:

• Detect overloads and faults in power circuits.
• Optimize energy consumption in production systems.
• Integrate with energy management systems in industrial plants.
• Automatically control motor and drive currents in real time.

In DC applications, such as battery charging, photovoltaic systems, or energy storage, measurement accuracy (typically ±0.5–1%) and high reliability are essential for the safe operation of the entire system.

Application of LEM transducers in power electronics

LEM transducers play a key role in power supplies, converters, and inverters:

• Monitoring current flow in DC and AC circuits and energy storage systems.
• Power control in power electronics systems, increasing energy efficiency.
• Protection against overloads and electromagnetic interference.
• Precise measurements in industrial installations with high current values.

Examples of applications include inverters, switching power supplies, UPS systems, photovoltaic installations, energy storage, and electric vehicles (EVs).

Measurement accuracy and reliability

LEM transducers are characterized by high accuracy, resistance to electromagnetic interference, and long service life. As a result:

• It is possible to precisely monitor current values in high-current circuits and industrial environments.
• Risk of failures is minimized, increasing safety of machines and devices.
• They enable energy quality control, system optimization, and increased energy efficiency.

Practical installation tips

To ensure proper measurement and system reliability, it is worth paying attention to:

• Proper connection of the current conductor – ensures measurement accuracy.
• Minimizing electromagnetic interference – using shielding and proper cable routing.
• Selecting a transducer for the current range – the output signal should be proportional to the energy flow.
• Considering the type of current (AC/DC) – selecting the appropriate measurement technology.
• Compliance with standards – for measurement safety and quality.

Incorrect cable routing, too great a distance from electronic systems, or incorrect range selection can introduce interference or measurement errors.

Summary

LEM transducers are indispensable in automation and power electronics, enabling precise measurement of current and voltage, energy flow monitoring, and increasing the safety and efficiency of systems. Their high accuracy, resistance to interference, and reliability make them suitable for both DC and AC applications, in machines, industrial equipment, energy storage systems, and electromobility.

We offer a wide range of LEM transducers that are ideal for automation and power electronics – see how our solutions can enhance the reliability and performance of your systems.