Congestion Management Using Optimal Placement of TCSC in Deregulated Power System

This paper presents a congestion management methodology in deregulated power systems by making use of optimal placement of thyristor controlled series compensators (TCSCs) in transmission network. The problem formulation consists of maximization of social welfare function subject to real and reactive power balance, constant power factor of consumers, transmission congestion (line loading), generators’ capability curve constraints, and bounds on variables. The social welfare function, which customarily comprises of demand benefits minus generation costs, has been modified to include the effect of usage cost of TCSCs. The proposed congestion management methodology takes into account number of potential scenarios of market conditions. The location of TCSCs in power system is decided by making use of integer variables; hence formulation of proposed problem takes the form of Mixed Integer Nonlinear Programming (MINLP) problem. The effectiveness of the proposed methodology is tested on a 5-bus and IEEE 14-bus systems and results obtained are compared with those obtained by existing approaches. It can be concluded that congestion management results obtained with proposed methodology are better than those obtained by existing approaches.