Active Harmonic Filter (AHF) is used for centralized harmonic suppression in a power system. Active Harmonic Filter in chennai is an IGBT based power electronics device. It uses IGBT and inverter technology.

It actively eliminates 100% harmonic distortion and reacts instantly to varying or Non linear loads. This is done by injecting additional currents as required in order to cancel the harmonic components of the non-linear loads.

Harmonics are unwanted frequency components and unbalance in terms of uneven power distribution between the phases in the electrical network.

Harmonics are produced by electronic loads which draw currents in a "chopped" manner and the current drawn by these non-linear loads are non-sinusoidal in nature. The level of harmonics is usually expressed as a ratio called Total Harmonic Distortion,

THD% = (RMS value of all harmonics) / (RMS value of the fundamental) in %.

The harmonic currents passing through linear loads generate harmonic distortion in the voltage wave shape, which will depend on both the nature of the harmonic currents and the impedance of the grid and loads. The harmonics norms in India, consistent with international standards like IEEE 519, have been fixed by the Central Electricity Authority (CEA) in their Technical Standards for Connectivity to the Grid Regulations, 2007. The regulations stipulate that the total harmonic distortion for voltage at the connection point shall not exceed 5% with no individual harmonic higher than 3% and the total harmonic distortion for current drawn from the transmission system at the connection point shall not exceed 8%. Now Power Utilities like TNEB have started levying penalties on consumers not only for low power factor but also when harmonics exceed the CEA norms.

Harmonic currents result in power that can't be used and which also takes up electrical system capacity. Large quantities of harmonics can lead to malfunctioning of the system that results in downtime and increase of the operating costs.

Harmonics are a problem for a wide number of business sectors and the costs are high and rising as the number of disturbances are increasing and modern production equipment is becoming more sensitive to these disturbances.

Every consumer of Electricity Board at 415 V should possess, who experience harmonic related issues such as:

  • Overload
  • Malfunction in control circuitry
  • Heavy application of electronic drives
  • Nuisance Tripping & mis-coordination of relays
  • Over heating of system components

Passive harmonic filters operate mainly on a fixed or stepped basis using passive elements. All these solutions suffer from the same drawbacks – they add losses, are installation specific and have no ability to adapt to or follow dynamic load changes.

The Active harmonic filter eliminate loss creating behaviors such as harmonics, flicker, voltage variations, resonances and reactive energy using a highly dynamic, step less digitally controlled compensation and filtering approach. By continuously monitoring the network and injecting exactly the right amount of compensation current – at exactly the right time – the most efficient and accurate solution to any power quality problem can be achieved.

This approach enables the current waveform to be restored instantaneously, the current consumption to be lowered and changes in load or installation conditions to be fully compensated at all times

For modern facilities, where load and network change constantly, this solution not only represents an opportunity, but is a necessity.
Cost reductions and efficiency improvements are major themes across all industries. As refinement becomes more and more all-embracing, further quick and easy improvements are difficult to identify. Optimization of the electrical network is an important but often overlooked area with significant potential. Active Harmonic filter technology lets you capitalize on:

  • Fewer production disturbances
  • Lower energy costs
  • Increased equipment lifetime
  • No penalty charges for reactive power or harmonic distortion
  • Increased network capacity leads to lesser investment needs
  • Lower operating costs
  • May release governmental tax reliefs
The Active Harmonic filter comes in useful when technical problems arise. Machinery and equipment connected to the same network might inflict disturbances on each other, causing low quality or reduced production performance. Connection of additional equipment drains transformer capacity and can turn power distribution into a bottleneck. By solving technical problems and freeing capacity, AHF allow for improved efficiency and optimal production conditions:

  • Fast enough to follow today's dynamic loads (response time < 1 ms)
  • Automatically adapts to changes in load or installation
  • Improves overall power factor
  • Eliminates resonance problems
  • Load balancing
  • Reduces heat and wear on motors, drives and other equipment
  • Frees power supply capacity
  • Allows for leaner specification of feeding gear

Linear Load examples

  • Incandescent Lamps
  • Motors
  • Transformers
  • Capacitors
Non-Linear Load Examples

  • VFD for Motors, AHU
  • UPS with SCR Rectifier
  • Computers
  • CFL, Mercury, Sodium and LED Lamps
  • Rectifiers
  • Induction Furnaces

  • Commercial installations with a set of non-linear loads representing less than 500 kVA (variable-speed drives, UPSs, office equipment, etc.)

    • Offices and commercial buildings
    • Hospitals, Malls
    • Data Centers
    • Printing Industry
    • Textile, Steel, Oil and Cement Industry
    • IT parks
    • Automotive Industry and Process plants

  • Installations where current and voltage distortion must be reduced to avoid overloads or Penalty.

Active Harmonic filters in chennai are available in capacity from 30Amp onwards.

Contact us for load study and power audit at your premises for a greener power solution…..