ACTIVE HARMONIC FILTERS
Harmonic currents occur in power networks due to non-linear loads, such as computers, frequency converters and UPS equipment. Among other things, the harmonic currents increase losses and cause malfunctions in electrical devices. When the level of harmonics in the network is so high that it may cause disruptions, a harmonic filter is required.
ACTIVE HARMONIC FILTERS
Harmonic currents occur in power networks due to non-linear loads, such as computers, frequency converters and UPS equipment. Among other things, the harmonic currents increase losses and cause malfunctions in electrical devices. When the level of harmonics in the network is so high that it may cause disruptions, a harmonic filter is required.
POWER QUALITY ASSURANCE
The active harmonic filter is designed for networks with a high level of harmonics to dynamically improve the quality of the electricity. An active filter is a particularly effective solution when there are a number of harmonic frequencies in the network (5th, 7th, 9th,…, 19th,…). In addition, the levels of harmonics may vary. The active filter generates an opposite current for each harmonic current, thus neutralising harmful harmonics. Additionally, the active harmonic filter enhances both the inductive and capacitive power factors. A suspected high level of harmonics can be confirmed with measurements.
PROPERTIES OF ACTIVE HARMONIC FILTERS
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Compensation current 400 - 400 A
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Modular construction also allows for compensation currents above 400 A
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3 or 4 wire version
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Voltage 200 - 690 V
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50/60 Hz
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Temperature 40°C without derating. 55°C with derating
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Air or water cooling system
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IP30, if necessary up to IP54
Harmonics
A functioning electric current and voltage should follow a sine wave pattern (BLACK). Some electrical devices cause distortions in the sine wave of the power network supplying the device. These distortions in the sine wave are called harmonics. Harmonics occur as multiples of the base wave frequency (DIFFERENT COLOURS). Harmonics compound into the base wave, causing a distorted sine wave (RED).
Sources of harmonics
Known sources of harmonics include frequency converters, switched-mode power supplies, thyristor switches, home and office electronics, UPS equipment, LED lights, and discharge lamps.
Harm
The harm caused by harmonics include increased disturbances in the power network and to the devices of electricity users, as well as in the reduced capacity of the equipment. Harmonics also cause faulty meter readings as well as malfunctions to automation equipment and protective relays.
