Soft Computing Techniques for Optimal Capacitor Placement - Complex System Modelling and Control Through Intelligent Soft Computations - page 587

To achieve these targets, and supplying the reactive power locally, it is necessary
to place the capacitor optimally in the distribution system. Several methods have
been developed, to place the capacitors optimally. These methods guide the dis-
tribution companies to obtain the (i) candidate buses for OCP, and (ii) size of the
capacitors. The objective of the OCP involves continuous (power and energy loss)
and discontinuous (Capacitor sizes), objectives. Such types of problems are termed
as mixed integer type problems. Several techniques have been proposed to solve the
capacitor placement problem. However, the solutions obtained using the soft
computing techniques are optimal as compared to that obtained using other
techniques.
This chapter aims to show the application of the soft computing techniques to
solve the optimal capacitor placement problem (OCP). In Sect. 2 , the structure of
the electric power distribution system is discussed along with the role of capacitors
in them. Section 3 presents the modelling of capacitor in distribution system and the
approach to solve the problem. A discussion on the classical approaches and soft
computing techniques used to solve the problem are illustrated in Sect. 4 . The
results for the application of the soft computing techniques are discussed in Sect. 5 .
Finally, the conclusions are drawn in Sect. 6 .

2 Electric Power Distribution System

The electric power system is divided into three parts, viz., generation, transmission,
and distribution, as shown in Fig. 1 Typically, the distribution system starts with
distribution substation, fed by one or more sub-transmission lines. However, in
some cases, the distribution substation is fed directly from the high-voltage trans-
mission line. These substations serve as one or more primary feeders. Largely, these
feeders are radial in nature, i.e., there is only one path for the power to flow from

the distribution substation to the user as shown in Fig. 2 (Kresting 2002 ; Gonen
1986 ). Further, the distribution system is divided into primary and secondary dis-
tribution system. The high capacity substations located at outskirts of the populous
area are connected via primary distribution system, whereas small substations to
supply the consumers are connected through secondary distribution.

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Fig. 1 Power system components (Kresting 2002 )