Computation of TCSC reactance and suggesting criterion of its location for ATC improvement

Deregulation of power system has brought major changes in the system operation and control. When open access is made available to the market players, one or more lines in the transmission network could be overloaded, thereby causing congestion. Congestion management can be achieved by improving available transfer capability (ATC) of the network. FACTS devices such as TCSC and UPFC have proven their utility for ATC improvement. The active power flow control can be done more effectively by these devices. Their design and installation need the determination of changes in parameters for maintaining the desired power flow in the line causing congestion. This paper proposes a new approach for determination of changes in the reactance of TCSC, required for achieving the desired transfer capability. Sensitivity analysis is used for computing the changes in line flow of the lines with and without TCSC. Also a suitable criterion with a mathematical model for computation of reactance is proposed for selection of a line for the installation of TCSC. Through the results, it is shown that ATC is improved to a specified value by the installation of TCSC in the selected line which has the reactance as computed by the proposed method.