Article

Distribution system reliability enhancement using optimal capacitor placement

Dept. of Electr. Eng., Sharif Univ. of Technol., Tehran
IET Generation Transmission & Distribution (impact factor: 1.2). 10/2008; DOI:10.1049/iet-gtd:20070515
Source: IEEE Xplore

ABSTRACT Failure statistics of most utilities indicate that distribution systems make the greatest individual contribution to the unavailability of supply to customers. Optimal capacitor placement in distribution systems has a number of advantages such as reducing losses, improving voltage profile, improving power factor and so on. The conventional objective function of the optimal capacitor placement consists of the total cost of losses and investments. Since capacitors supply reactive loads locally, they improve the load-carrying capability of the lines and therefore play the same role as redundant lines. Thus, optimal capacitor placement can also improve the reliability indices of a distribution system. Therefore two new objective functions are defined here. The first one is defined as the sum of reliability cost and investment cost. The second is defined by adding the reliability cost, cost of losses and investment cost. The latter is a comprehensive objective function which is the resultant of the conventional and reliability-based objective functions. This problem is solved using a particle swarm optimisation-based algorithm. The effectiveness and applicability of the proposed approach are examined using a distribution network.

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Keywords

advantages
 
capacitors supply reactive loads
 
comprehensive objective function
 
conventional
 
conventional objective function
 
distribution system
 
distribution systems
 
Failure statistics
 
greatest individual contribution
 
lines
 
load-carrying capability
 
new objective functions
 
optimal capacitor placement
 
particle swarm optimisation-based algorithm
 
proposed approach
 
redundant lines
 
reliability indices
 
reliability-based objective functions
 
total cost
 
unavailability