Optimal Location of FACTS Devices by Evolutionary Programming Based OPF in Deregulated Power Systems

This paper presents an Evolutionary Programming (EP) based approach for solving the optimal
power flow with Flexible Alternating Current Transmission (FACTS) device to eliminate
transmission line congestion in deregulated power system. Congestion in the transmission lines is
one of the technical problems that appear particularly in the deregulated environment. In the
deregulated power industry, private power producers are increasing rapidly to meet the increase
demand. The purpose of the transmission network is to pool power plants and load centres in order
to supply the load at a required reliability, maximum efficiency and at lower cost. As power
transfer increases, the power system becomes increasingly more difficult to operate and insecure
with unscheduled power flows and higher losses. The objective of FACTS devices is to control
power flow so that it flows through the designated routes, increase transmission line capability to
its maximum thermal limit, and improve the security of transmission system with minimal
infrastructure investment and environmental impact. Thyristor Controlled Series capacitor (TCSC)
is an emerging FACTS device used in this paper to reduce the congestion. The proposed approach
introduces performance index parameter to locate TCSC optimally for relieving the congestion. In
congestion management, the objective function is nonlinear. Hence an EP based approach is
applied to solve the Optimal Power Flow (OPF) problem. IEEE 14 bus system is considered to
demonstrate the suitability of this algorithm and the results are appreciably good.