Determination of ATC with PTDF using linear methods in presence of TCSC

Open access to the transmission system places an emphasis on the intensive use of the interconnected network reliably, which requires knowledge of the network capability. Fast, accurate algorithms to compute network capabilities are indispensable for transfer-based electricity markets. Available Transfer Capability (ATC) is a measure of the remaining power transfer capability of the transmission network for further transactions. Transmission System Operators (TSOs) are encouraged to use the existing facilities more efficiently. Most transfer studies involve contingencies and multipattern scenarios that often can only be performed in reasonable time with the use of linear methods. One of the limitations of linear ATC is the error produced by neglecting the effect of reactive power flows in line loading. This paper presents the application of one type of Flexible AC Transmission System (FACTS) device, the Thyristor Controlled Series Compensator (TCSC) to improve the transfer capability of a power system incorporating the reactive power flows in ATC calculations. By redistributing the power flow, the ATC is improved. Studies on a sample IEEE14-bus power system model are presented to illustrate the effectiveness of TCSC device to improve available transfer capacity as well as voltage profile.