Most of the mentioned filtering techniques have common drawback of higher cost compared to Passive Filtering techniques. Consequently, the harmonic filtering techniques to a large extent are still the most commonly used techniques for current harmonics mitigation of 6-pulse front-end diode rectifier application.
We have developed an efficient Passive Filter, which can suit many such similar loads. Since all filter components are passive they are rugged, maintenance free, reliable and low cost. Moreover, the filter implementation procedure is relatively easy.
With simple structure, our Passive Filters have been extensively used for VFD harmonic mitigation. No involvement of electronic circuits, hardware and complicated control algorithms. Hence, our Passive Harmonic Filters are relatively inexpensive means for eliminating current harmonics distortion and improving the system power factor. Because of these two in one improvement our broad band filters usually have edge over the other effective filtering methods.
Readings on 75 KW Filter connected to 75 KW VFD
(Voltage THD was 2.8% for the following readings)
Original THD-I 31%
** Other ratings on request