Design and Installation of Active Filters for Power Quality Improvement for Water Treatment Plants

This paper presents a simple of active power filters (APF) design techniques to minimize harmonic distortion and improve power factor caused by a harmonic source such as variable-frequency drives (VFDs) using 12-pulse converters. A method is finding the maximum rating of active power filter to minimize voltage and current harmonic distortion at a load bus where it is desired to maintain the displacement power factor at a desired level constraining the compensator value, which would create resonance condition. The water treatment plants require the operation of many parallel-connected VFDs on the same bus, such as a system significantly increases the power quality problems. The purpose of APF is sufficient to eliminate the harmonic currents, balance currents of the ac line input and increase power factor. The results show that the APF are a very appropriate solution for most typical harmonic problems, unbalanced current and power factor correction.