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Solutions to filter harmonics on power systems

The increasing use of modern power electronics (drives, uninterruptible power supplies, etc.) generates nonlinear currents and thus loads the network with harmonics. The capacitance of the capacitor forms a resonant circuit in conjunction with the power supply transformer. Experience shows that the self-resonant frequency of this circuit is usually in the range of 250 – 350Hz, located in the 5th and 7th harmonic regions. Typical loads that need harmonic filtering include 6 pulses (AC/DC). ), 3-phase UPS, inverter.

Active Harmonic Filters

With BTB Electric’s active harmonic filtering will reduce your THD levels to within IEEE/CEA limits. These filters are IGBT based power converters. This filter injects the negative of the harmonic current resulting in practically no harmonic distortion. Phase equalization and power factor correction are also achieved.


30-900A Active Harmonic filter in 3 phase 3 wire/4wire
Stand-alone & modular units
Response time less than 20 ms
Easy diagnosis of fault conditions with alarms
Easy configuration & parameter monitoring with LCD touch screen HMI
Reactors – Harmonic Filtering

The differential harmonic filter is a series combination of a reactor and a capacitor. This filter provides higher impedance for high frequency harmonics. This prevents resonance and amplifies harmonics.

7% reactors have a slight reduction in harmonics of the 5th order or higher. For industries with drives, converters and other power electronics
14% of reactors have a slight drop in harmonics of 3rd order or more. For IT industry and For industry with high single-phase non-linear loads


Available as 7% (189 Hz) & 14% (134 Hz) detuned filters
Copper & Aluminium wound reactors
Very low operating losses ≤ 5 W/kVAr
High linearity – 1.8 times the rated current
Low noise
Auto-thermal cut-off (1350C)

Date Submitted 10:29 - 31/03/2024 - Updated at: 10:29 AM , 31/03/2024
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