A Novel Online Fuzzy Control Method of Static VAR Compensation
for
an Effective Reactive Power
Control of Transmission Lines
ABSTRACT:
The Flexible AC Transmission System (FACTS) technology is a promising technology to achieve complete deregulation of Power System i.e.
Generation, Transmission
and Distribution as the
complete individual units.
FACTS is based on power electronic devices,
used to
enhance the existing
transmission capabilities in
order to make the transmission
system flexible and independent in operation. The loading capability of transmission
system can
also be enhanced nearer to its thermal limit without affecting the stability. Complete closed-loop
smooth control
of reactive power can
be achieved using shunt connected FACTS
devices. Static VAR Compensator (SVC) is one of the shunt connected FACTS devices, which
can be utilized for the
purpose of reactive power compensation. As the
Intelligent FACTS devices make them adaptable, it is emerging
as the
present state
of the art technology. This
paper presents the design and simulation of the Fuzzy logic control to vary firing angle of SVC in order to achieve
better, smooth
and adaptive control
of reactive power in transmission
systems. The design, modeling and simulations are carried
out for the
λ/8 Transmission line by placing
the compensation at the receiving end (load
end) and the results obtained demonstrates
the effectiveness of
the proposed method.
KEYWORDS:
1. Fuzzy Logic
2. FACTS and SVC
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:
Fig. 1.Structure of
fuzzy logic controller..
Fig.2. Single Phase equivalent
circuit and fuzzy logic control structure of SVC.
This
paper presents an “online Fuzzy control scheme for SVC” and it can be concluded
that the use of fuzzy controlled SVC (FC-TCR) compensating device with the
firing angle control is continuous, effective and it is a simplest way of
controlling the reactive power of transmission line. It is observed that SVC device was able to compensate both over
and under voltages. Compensated voltages are shown in Fig. 17 and Fig. 18. The
use of fuzzy logic has facilitated the closed loop control of system, by designing
a set of rules, which decides the firing angle given to SVC to attain the
required voltage. With MATLAB simulations [4] [5] and actual testing it is observed
that SVC (FC-TCR) provides an effective reactive power control irrespective of
the load variations.
REFERENCES:
1.
Narain. G. Hingorani, “Understanding FACTS, Concepts and
Technology
Of flexible AC Transmission Systems”, by IEEE Press USA.
2.
Bart Kosko,
“Neural Networks and Fuzzy Systems
A Dynamical
Systems Approach
to Machine Intelligence”, Prentice-Hall of India New Delhi, June 1994.
3.
Timothy J Ross, “Fuzzy
Logic with Engineering
Applications”, McGraw-Hill, Inc, New York, 1997.
4.
Laboratory Manual for Transmission line and
fuzzy Trainer Kit Of Electrical Engineering Department NIT Warangal.
5. SIM Power System User
Guide Version 4 MATLAB Manual
