P O BOX: 115105, Dubai – UAE
P O BOX: 115105, Dubai – UAE

Active Harmonic Filters (AHF)

Active harmonic filters or simply harmonic filters are devices that suppress the harmonics in the electrical network. Harmonics are higher frequency voltages and currents which are superimposed on the fundamental waveform, creating a distorted wave pattern. Conventional harmonic filters are resonant circuits designed to block the harmonic currents. It mitigates the harmonic flow from the source to the power system. Modern active harmonic filters (AHF) use IGBT technologies for the harmonic reduction. Active harmonic filters will inject equal and opposite harmonics to cancel out harmonics in the system. The distorted waveform will be modified to clean and sinusoidal.

To evaluate the actual harmonic distortion in the system, we carry out onsite power quality and harmonic measurements for detailed analysis. With help of the analysis results the predominant harmonic orders and magnitude of distortion caused by each harmonic order is determined. International standards are followed to validate the total harmonic distortion limits. If the networks total harmonic distortion found above this standards, harmonic reduction methods and solutions will be provided. Active harmonic filters are the most efficient method to rectify the harmonics. With the harmonic analysis results, suitable harmonic filters are designed and recommended.

These following characteristics and functions have been implemented in Active Harmonic filters :
  • Filtering capacity per module of 100 A, capacity per cabinet between 100 A to 400 A (Floor mounted type).
  • Filtering capacity per module of 30 A, 60 A and 100 A (Wall mounted type).
  • Modular design to expand the ratings using small sized rack-modules.
  • Range for installations with 3 wires (3W model) or 4 wires (4W model).
  • Multi-range voltage and dual frequency (50/60 Hz)
  • Reduction of harmonic currents up to the 50th order harmonic (2,500 Hz)
  • Selection of harmonic frequencies to be filtered for maximum filter effectiveness.
  • Power factor correction both inductive and capacitive.
  • Load Balancing/Phase current balancing and reduction of neutral loading (4W model)
  • If higher filtering capabilities are required, the system can be expanded using racks connected in parallel.