Relief of the supply network by compensating the harmonic reactive power

REO – energy in its purest form

REO is a leading manufacturer of inductive components and systems. Since its foundation in 1925, the adjustment of current and voltage, the development and
manufacture of inductors and the elimination of disturbances have played a central role in the company’s core business. Today, its extensive know-how is reflected in a wide range of chokes in the input, intermediate and output stages of modern convertor techology.

Nevertheless, it is new ideas and in particular a high development potential that sets REO apart and allows the realization of systems with the highest reliability. With our standard products as well as with customer-specific solutions we serve markets in the field of drive technology, railway technology, renewable energies or electromobility.

Chokes of REO

  • Extensive product range
  • Manufacturing according to DIN EN 60931-1 and all EMC-relevant standards, e.g. EN 55011 and 61800-3
  • UL-certified products
  • Personal technical advice
  • Customer-specific solutions
  • REOplus: REO speaks your language – with worldwide sales offices and production facilities, REO is always close to its customers and can therefore react quickly, efficiently and cost-effectively.
  • All products are developed and tested according to DIN VDE 0565.

Our strengths – your advantage

Our experience in railway technology, which goes far beyond the requirements of “normal”
drive technology, enables us to develop highly efficient components that work reliably and over
the long term even under extreme conditions.

As a manufacturer of test systems, REO is an expert in quality and has its own test facilities which, thanks to their modular design, can simulate real-life conditions and thus serve optimum product development. Our technical experts ensure that you are not alone when buying or developing chokes – we offer you various services, such as measuring the chokes or our on-site service, which determine the exact technical conditions and enable us to offer you an economically and technically flawless solution.

With development, production and sales facilities in Europe, Asia and North America, we can react quickly on site and support you in the early stages of your projects with development and manufacturing expertise.


Mains choke

A line reactor relieved the supply network by compensating the harmonics reactive power, The harmonics are greatly reduced.

The conditional by the operating principle of rectification very high current peak is attenuated by the inductance by more than 60 %.

Harmonic Filter

REO harmonic filters are used for reducing the THD (Total Harmonic Distortion).
The harmonic currents are greatly suppressed, so that a THD is achieved by less than 5 % (as in UPS systems) .
Further reducing reactive power through a harmonic filter (e.g. REOWAVEpassive) and save up to 30% energy.

DC-Link chokes

A DC reactor relieves the supply network by compensating the harmonics reactive power. Similar to a line choke, the DC-link choke acts as a passive component and helps to reduce harmonics and relieve the supply network. The DC choke attenuates also the peak load current of the DC link capacitors.

DV/Dt – Chokes/Filter

REO dv/dt chokes and filters attenuate due to their structure the voltage rise to acceptable values.

For short cable lengths between inverter and motor a dv/dt choke limits the increase speed to less than 1000 V/μs, which is sufficient for most motors and standards.

Motor chokes

Reduction of symmetric and asymmetric flow distortions, which are generated at the connecting line between the inverter and the motor due to the fast switching of the power semiconductors.
These disturbances can affect the performance of the engine by loud noises, and in extreme cases, by overheating. Here, a conventional motor choke can help.

Sinusoidal filter

Sinusoidal output voltage for your frequency converter

Advantages of REO Sinus filter :
– Output voltage is sinusoidal
– Also suitable for very long motor cables
– Shielded motor cable is not required
– The efficiency of the overall system is increased
– Reduce motor noise and eddy current losses

Buck converter chokes

The buck converter choke as an inductive passive component in the power supply and in power electronics is used to attenuate unwanted frequencies or for saving energy and storage.

Advantages of the buck converter inductor:

– Use in the kHz range possible
– Equal strength or higher power in smaller construction
– Significantly lower weight


Air chokes are used when a particularly high linearity is required. By its relatively simple structure, they are not only compact, but also very stable.

– No saturation effects
– High linearity L (i)
– Very good mechanical resistance
– No hysteresis

Test chokes

Inductive loads are usually specially designed for an application and with reference to the applicable norms. These standards detail the tests required but also the test setups and procedures. The inductances are specially adapted to the area of application so an optimal solution may be provided.

Inductive load units are used when power supply systems or other test specimens, such as switches, contacts or frequency converters have to be loaded with a standardized effective andreactive power.

Liquid-cooled chokes

With the help of liquid cooling losses are derived specifically about the cooling circuit and not in the environment.

By use of liquid cooling, the temperatures in the components can be reduced greatlyie less stress for the insulation materials and longer life.

Train chokes

REO has set itself the task of helping to ensure that trains are safer today and in the future. With special chokes for rail technology, we ensure that a safe operation is possible and EMC problems are eliminated at source.

Thus, voltage changes, short circuits and other phenomena that occur in dealing with electricity, does not endanger crew members and passengers. Compliance with international standards such as EN 45545 or EN 60310, the use of the latest technologies and decades of experience make REO a strong partner.

Air chokes

Air chokes are used when a particularly high linearity is required. By its relatively simple structure, they are not only compact, but also very stable.

– No saturation effects
– High linearity L (i)
– Very good mechanical resistance
– No hysteresis

Individual solutions

Are you looking for an individual solution? No problem! Our REO experts will be happy to answer any questions you may have.