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Frijsenborg biogas plant

ADF P300 installation biogasplantIn Denmark, Wefri A/S, which oversees the historic estates of Frijsenborg and Wedellsborg, seeks to create a closed ecosystem that is not a burden on the climate. Therefore, they use locally produced raw materials and recycle all their agriculture and forestry resources. As part of the recycling process, there is a biogas plant at Frijsenborg. When Frijsenborg’s power supply company detected high levels of harmonics which was above limit set, Danfoss Drives service partner, Styreg, was hired to measure the harmonic distortion and advise Frijsenborg on the best solution.

As a temporary solution, Styreg installed an ADF P100 150A Filter to reduce the harmonic current. Meanwhile, Danfoss calculated the filter size, and the customer installed a container and a new switchboard for the filter connection. Styreg then installed two ADF P300 360A and one ADF P300 120A on the transformer, and CTs were connected for multi-master operation.

“Comsys Active Dynamic Filters (ADF) were commissioned during low production of biogas to reduce the THDi below the 5,6% limit set by the power supply company. Everything went smoothly, which is one of the many reasons why we always recommend Comsys Active Dynamic Filters to our partners. Next week we are finetuning the filters at max production of biogas.”

– Kim Tonsberg Kristensen, Styreg ApS

To meet the increased demand of our Active Dynamic Filters (ADF) we are opening a new manufacturing facility in a city on another continent. This is an important step in our commitment to give the best possible service to our partners and customers.

We will not reveal where quite yet, but maybe you can find it out in below video? 


It is important to Comsys that our partners and customers are confident that our products meet the standards required for their projects. Since 2018 our Active Dynamic Filters (ADF) have been certified by DNV. Now we are thrilled to announce that we can also offer Lloyds Register type approval for ADF P100, ADF P300, ADF P200 and the PPM 300 for system integration purposes.

This type of approval certificate confirms that our ADF’s comply with recognised industry quality standards and that they are in full compliance with the LR rules, which shortens the lead time and hassle for our Lloyds customers.

 Lloyds type approval website 01

About Lloyd’s Register:
Lloyd’s Register started out in 1760 as a marine classification society. Today, they are one of the world’s leading providers of professional services for engineering and technology. Their aim is to improve safety and increase the performance of critical infrastructures for clients in over 75 countries worldwide.

Port of Visby

Shore-to-ship power supply installations are a vital part of reducing emissions in ports. When ships connect to a land-based power supply, they can stop their auxiliary engines and drastically reduce emissions, noise, and vibrations.

To materialize a shore-to-ship connection, both the shore connection and the ship have to be compatible. In Europe, most countries use 50 Hz net frequency while ships typically use 60 Hz net frequency. Therefore, a frequency converter must transform the power and bridge this difference. When installing a frequency converter, the power conversion problem is solved, but unfortunately, there is also an increase in harmonic distortion.

An Active Dynamic Filter (ADF) can remove harmonic distortion. The filter detects and analyzes distortions so it can precisely inject a compensation current that eliminates the harmonics. The reduction of harmonic current can increase the transformer lifetime while reducing heat losses and total current in the wires.

In 2019 Actemium was contracted for a 2x 1.8 MW 10.7kV shore connection project for three berths in Port of Visby, Sweden. CG Drives & Automation (Emotron) delivered a 12-pulse power converter to the project, and Comsys supplied a unit of ADF that removed harmonics generated by the systems frequency converter even further!

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