Power quality considerations on shunt/series current and voltage conditioners

The paper presents the basic concepts of power quality considerations, especially when current, voltage or both present nonsinusoidal waveforms. The use of shunt compensator for current harmonic or unbalance compensation or the use of series compensator for voltage harmonic or unbalance compensations is discussed. Then the advantage of using hybrid passive and active power filter is also discussed. The association of shunt and series active filter composing the UPQC (universal power quality conditioner) which can guarantee perfect voltage and current harmonic compensation is presented. As a result of the generalization of the concept of the UPFC (unified power flow controller) associated with the concept of UPQC, the UPLC (universal active power line conditioner) is presented, which can compensate voltage and current harmonics as well as control the power flow in a transmission line.