Design and Implementation of Hybrid Active Power Filter

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ABSTRACT
This paper deals with a hybrid active power filter
with injection circuit (IHAPF). This paper concluded
that the stability of the IHAPF based on detection
supply current is superior to that of others. To
minimize the capacity of IHAPF, an adaptive fuzzy
dividing frequency-control method,.The generalized
integrator is used for dividing frequency integral
control, while fuzzy arithmetic is used for adjusting
proportional-integral coefficients timely. The
simulation results shows that the new control method
is not only easy to be calculated and implemented,
but also very effective in reducing harmonics.


INTRODUCTION
Hybrid active filters for harmonic-current filtering
Two types of hybrid active filters for harmoniccurrent
filtering of nonlinear loads were proposed in
1988 and in 1990, respectively. Figure 1.8 and Fig.
1.9 show the simplified circuit configurations of the
hybrid active filters. The two hybrid filters are based
on combinations of an active filter, a three-phase
transformer (or three single-phase transformers), and
a passive filter consisting of two single tuned filters to
the 5th- and 7th-harmonic frequencies and a secondorder
high-pass filter tuned around the 11th-harmonic
frequency


Topology of the Novel Hybrid Active PowerFilter

The parallel HAPF has the advantages of easy
installation and maintenance and can also be made
just by transformation on the PPF installed in the
grid. Fig. 1 shows a PHAPF that is in use now. To
reduce the power of APFs, a PPF has been designed
for some certain orders of harmonics


Fuzzy Inference System
Fuzzy inference is the process of
formulating the mapping from a given input to an
output using fuzzy logic. The mapping then provides
a basis from which decisions can be made, or patterns
discerned. The process of fuzzy inference involves all
of the pieces that are described in the previous
sections: membership functions, fuzzy logic
operations, and if-then rules.