In this paper the authors discuss the transient
performance of a DSP-based power active filter, when
subjected to sudden changes on both the instantaneous
reactive power and oscillating active power demanded by
a three-phase AC/DC rectifier, whose firing angle moved
transiently from one value to another. A voltage source
AC/DC inverter fed, either by a constant DC source, or
by a previously charged DC capacitor, acts as a main
compensator device for the active filter, whose transient
performance was investigated under the action of these
two types of DC vottage sources.
Digital simulation and laboratory tests demonstrated that
under the action of a constant DC source, the DSP- based
active filter performed complete harmonic current
sttppressh, and instantaneous reactive a d osciktirtg
active power compensation, under all circumstances of
firing angle variations. When the active filter is supplied
by a DC capacitor, a partial compensation is achieved,
that improves when the amount of instanttaneotts reactive
power becomes larger than the instantaneous oscillating
active power.