A novel active three phase AC-voltage conditioning scheme for suppressing power line distortions

Power electronic and other nonlinear loads connected to a power grid cause severe higher harmonic line distortions. This requires additional filtering expenditure to suppress voltage and current harmonics in the feeding lines. So far, this filtering is mostly implemented by passive filters connected between line and load. Active filtering schemes have been used for current harmonics suppression. This paper focuses on a solution where the power line voltages are conditioned such that higher voltage harmonics are suppressed by an active power electronic filter. The control strategy has been designed to instantaneously balance voltage overshoot with deficiency. The scheme presented here allows for reshaping of the AC-line voltage to any desired shape. It is shown that this scheme is capable of suppressing line voltage harmonics for an example power electronic load. The simulations were performed using SIMPLORER/sup (R)/.