Active Harmonic Filters

An active harmonic filter is a higher sophisticated device to prevent harmonic distortion in a power network. Over the last decade the intensity of the usage of power electronic equipment has caused a dramatic increase of the harmonic disturbances in power systems. Especially the randomly varying amplitudes and harmonic content of the distortion power can make a passive harmonic filter solution become ineffective. Furthermore the load conditions and different configurations nowadays are causing harmonics up to the 50th order. The more sophisticated active filtering concepts operate in such wide frequency ranges, adapting their operation to the resultant harmonic spectrum.

Active harmonic filters (AHF) are power quality devices that permanently monitor the nonlinear load and dynamically provide precisely controlled current. This current has the same amplitude of the harmonic current but is injected in the opposite phase-shift. This cancels out the harmonic currents in the electrical system. As a result, the current supplied by the power source will remain sinusoidal since the harmonics will negate each other and the harmonic distortion is reduced to less than 5% THDi, meeting all standards. In addition, the AHF power electronics platform has been designed to operate at levels that continuously adapt to rapid load variations

• Essentil to reduce harmonic levels under IEEE 519 limits
• Available from 30 to 600 A, 415 & 690 V, 50/60 Hz
• Available in both versions : 3P3W & 3P4W
• Operation modes : Harmonic filtering, power factor correction, and phase balancing

• Programmable selective harmonic elemination
• Interface : RS485 (Modbus RTU), TCP/IP (Ethernet)
• IGBT base power electronic technology
• Neutralizes harmonic currents by phase opposition signals nd th • Capable to filter 2 to 50 harmonic orders

• Ultra fast reaction time : < 200 milisec
• Noise level : < 60 dB
• Switching frequency : 24 kHz
• Control frequency : 48 kHz
• Flicker compensation feature
• Standards : IEEE 519, IEC 61000-3-6, ER G5/4
• Enclosure : IP00
• Ambient temperature : -10 to 50° C
• Power loss : < 3% of rated power
• Humidity : 95% non-condensing
• Cooling : Forced air
• Easy to install and maintenance freE
• Small footprint and low acquisition and life-cycle cost
• Ease of integration
• Unlimited scalabilit
• Efficient commissioning, control and reporting
• In addition to active harmonic filtering active filters can also be used for voltage stabilization, power factor improvement, flicker mitigation and load balancing applications.