Active Harmonic Filtration (AHF)

Installation

Maintenance

Remote Monitoring

What is Active Harmonic Filtration?

Active Harmonic Filtration is basically an inverter based harmonic current source that measures the magnitude and phase of the load current harmonics.

Active Harmonic Filtration via the use of  Active Filter control, synthesises the load harmonic currents but phase shifts them by 180°. This harmonic anti-phase current is injected into the system and combines with the load current to create a supply current that has a much-reduced level of harmonic distortion.

The principal of operation is shown graphically in the illustration.

What Effects Do Harmonics Have?

  • Excessive heating in cables (skin effect)
  • Premature failure of power supplies
  • Premature failure of power factor correction capacitors
  • Overheating of non-k rated transformers
  • Nuisance tripping of peak-sensing breakers
  • Noise in comms / data systems (where there is no segregation)
  • Overheating of three-phase motors
  • Mechanical damage to three-phase motors
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What can be done about Harmonics?

Following on from an harmonics analysis of the sites supply, Active Harmonic Filtration (AHFs) can be implemented to help minimise the distortion.

Active Harmonic Filtration works by putting harmonics back into the electrical system in an equal and opposite measure to the existing harmonics. Active Harmonic Filtration Equipment can be designed to target all harmonics or just the harmonics that are causing a specific issue to site.

As part of the load and harmonic analysis report we can provide a complete, no-obligation quotation for installing Active Harmonic Filtration as required.

If you wish to arrange a week long load and harmonic analysis please feel free to contact us.

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AHF
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Active Harmonic Filtration – Servicing

AHF
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Already Have Active Harmonic Filtration?

In order to maintain the effectiveness of your Active Harmonic Filtration regular servicing is critical for keeping your site energy performance at its best.

During our servicing we make sure that the filter is correctly calibrated to the sites current load requirements and that internal components are not showing any signs of deuteration or overheating.

Ventilation will be checked and fan filters changed as required. Software updates can be implemented for Active Harmonic Filtration modules and HMI displays.

Find out how we can help take care of the annual servicing of your Active Harmonic Filtration equipment. As part of the service, we offer free reminders for scheduling maintenance visits so that they’re never missed. Contact us to see if we’ve been to your site before and when your service is next due.

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Meet Our Partner – Comsys

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PFC Engineering Ltd has partnered with Active Filter Manufacture Comsys to bring you state-of-the-art Active Harmonic Filtration solutions.

Founded in 2001 by a small group of Swedish engineers, today Comsys is a well-established and rapidly growing company with Active Dynamic Filters being their number one innovation since the start.

Combined with PFC Engineerings’ 50+ years in the Power Quality industry we aim to provide sustainable energy solutions custom-made for your site’s requirements, saving you money and helping to reduce your site’s Harmonic Distortion levels.

Latest News – Active Harmonic Filtration

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Active Harmonic Filter Installation – Alloa, Scotland

Initial Site Condition The existing Power Factor Correction (PFC) system at the site was rated at 300 kVAr, configured in three stepped stages. On inspection, the following conditions were recorded: Step 1: Operating at ~55% capacity,…
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Installation of 2 Revcon 200A Active harmonic filters in central London

We were contacted to investigate the increasing harmonic distortion at a large office building in the centre of London, following sites ongoing modernisation plan. After carrying out a week-long Power Quality Analysis, we noticed that while…
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100A Harmonic Filter Install at Magistrates Court

During a planned upgrade of this site's main LV Panel, it was recommended that some Filtering equipment be installed to help reduce the site background Harmonics. We were then approached to find a solution, and upon review of all the site's…
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Revcon Harmonic Filter Install

During the annual Power Factor Correction maintenance at a large Salad Factory in the south of England, it was found that the standard PFC on site was failing.   An instantaneous load and check carried out by on service engineer show…
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Active Harmonic Filter With PFC Install at Recycling Plant

A recent catastrophic failure of a 200kVAr Power Factor Correction unit on the main incoming supply at Large Recycling Centre has raised concerns that the quality of the supply may in some way be compromised, resulting in this failure.   In…
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Active Harmonic Filter Installation – Cardiff

We recently carried out the second phase of our Active harmonic filter installations at a large insulation manufacturer in Cardiff.   This supply now consists of 3 x 180amp P300-180/690V units connected in a Master/Slave/Slave configuration…
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PFC & AHF Commissioning Ireland

During a recent trip to Ireland, we carried out the commissioning of 6 Active Harmonic filters and 3 new Power Factor Correction units at a large horticultural manufacturing site. All the equipment had been shipped to the site and installed…
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Active Harmonic Filter Replacement

We are contacted by an insurance business that occupies a large commercial building in central Ipswich regarding the failure of an Active Harmonic Filter on one of the LV supplies. We already carry out the annual Power Factor maintenance…
Active Harmonic Filter
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Active Harmonic Filter Installation

Harmonic levels at a large grain storage and drying factory had, over the past few years, crept slowly up in distortion eventually leading to some major equipment failures. This increase was also having a detrimental effect on the Power Factor…

Active Harmonic Filtration FAQs

Active Harmonic Filtration is basically an inverter based harmonic current source that measures the magnitude and phase of the load current harmonics. The Active Harmonic Filtration Equipment injects compensation current that are the exact opposite to cancel out the load behaviour.

Harmonics in an electrical system mean that current and voltage are distorted and deviate from sinusoidal waveforms.

Harmonics are produced by an electrical load that draws current not directly proportional to the voltage referred to as Non-linear loads. An example of this type of load include:

  • Inverter drives
  • DC Drives
  • Uninterruptable power supplies (UPSs)
  • IT Equipment

Yes, subject to available space, the Active Harmonic Filtration components can be custom built into any existing panels on site in a ‘plug & play’ style installation.

Active Harmonic Filtration Equipment comes in a variety of output sizes and a full site survey and analysis will need to be carried out prior to any new installation. This can be carried out by PFC Engineering Ltd and on completion we will provide you with a full detailed site loading report along with any recommendation and quotations required.

During a annual service of your Active Harmonic Filtration some of the main tests we carried out are:

  • Insulation resistance of power cables
  • Fuse checks
  • Full physical tightness check of all terminals
  • Full clean out of equipment cubicle and vents
  • Full function tests of HMI
  • Check the operation of Fans and quality of filter elements
  • Site Load survey with and without filter in circuit
  • Review of all harmonic set points
  • Event log review
  • Thermal Check
Any questions? Please get in contact, we would love to hear from you.
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