Overview of AHF

ZDDQ Active Harmonic Filter(APF/AHF for short) is a perfect comprehensive solution to power quality problems with power grid such as harmonic wave(can filter 2nd to 50th harmonic interference completely), reactive power, and 3 phase load unbalance.

Active Harmonic Filter is connected in parallel in power grid, to detect the harmonic wave in power grid in real time, generate the reverse-phase compensation current through the converter, and dynamically filter the harmonic wave in power grid. The operation of AHF is unaffected by power grid structure and load type, and it will not produce harmonic oscillation with the system, thus perfectly realizing harmonic wave control of various loads.

Active Harmoinc Filter can also realize dynamic reactive compensation, and control the capacitor switching, to improve the power factor of power grid. Meanwhile, AHF has the function of controlling the 3 phase load current unbalance, thus comprehensively solving various power quality problems with power grid.

Active Harmonic Filter module	Rack type AHF panel

Specification of AHF

Email us hanson@chinazddq.com,or click Active Harmonic Filter Datasheet to download details.

AHF principles

Active Harmonic Filter is connected in parallel with non-linear loads, and uses one set of current transformers (CT) to detect the load current. It calculates each order harmonic current , and then generates a compensating current with the same amplitude but opposite phase angles to the detected harmonic current, which cancels out the original load harmonics.
The AHF not only eliminates harmonic current from the load side, but it also mitigates harmonic voltage caused by harmonic currents. The AHF system can also improve power factor (PF) and correct load imbalances in the power system.

Active Harmonic FIlter Principle	Active Harmonic Filter Interface

AHF Benefits

■Ultra-fast reactive power compensation(Inductive and capacitive).

■Harmonic Compensation up to 50th harmonic(Individual selectable).

■Load balancing between phases and unloaded neutral wire.

■Flicker compensation.  

■Reduce overheating/Redue nuisance tripping/Reduce overloading/ Reduce equipment failure.

■Improve Reliability.    

■Compact Design and Modular system.

■Grid resonance detection.

■User-friendly HMI menu operation.

■Ethernet and ethercat system for interconnection.

■High performance and reliability.

■Insensitive to network/grid condisitons.

■Simple installation.

Quality Test Room of Active Hamronic Filter	active harmoic filter aging and reliability test

AHF application

■Industrial installations with a set of non-linear loads representing more than 500kVA (variable-speed drives, UPSs, rectifiers, etc.)

■Installations requiring power-factor correction.

■Installations where voltage distortion must be reduced to avoid disturbing sensitive loads

■Installations where current distortion must be reduced to avoid overloads

Following are typical application industries of Active Harmonic Filter.