The protection of sensitive loads from interharmonic currents using shunt/series active filters

The paper discusses the operation and control algorithms of shunt and series active filters. Performance of each of these filters is studied separately when it is connected to protect sensitive loads in a power distribution system. It is assumed that the distribution system is polluted due to the presence of the loads that may be unbalanced and draw interharmonic currents from the feeder. Separate algorithms have been proposed for the shunt and the series active filters. These are operated such that the voltage waveform at the sensitive load bus terminal is a clean balanced sinusoid. The proposed algorithms are verified through the computer simulation studies using PSCAD/EMTDC software package.