The increasing use of modern power electronic apparatus (drives, uninterruptible power supplies, etc.) produces nonlinear current and thus loads the network with harmonics. The capacitance of the power capacitor forms a resonant circuit in conjunction with the feeding transformer. Experience shows that the self-resonant frequency of this circuit is typically between 250 and 500 Hz, i.e. in the region of the 5th and 7th harmonics. Typical loads requiring harmonic filtering include 6 pulse drives (AC / DC), 3 phase UPS, frequency converters
Active Harmonic Filters
With L&T’s active harmonic filters, reduce your THD levels to within IEEE/CEA limits. These filters are IGBT-based power converters. This filter injects negative of the harmonic current resulting in practically no harmonic distortion. Phase balancing and power factor correction is also achieved.
Reactors – Harmonic Filtering
Detuned harmonic filters are the series combination of a reactor and power capacitor. This filter offers higher impedance for high frequency harmonics. This prevents harmonic resonance and amplification.