Optimal Placement of TCSC by Sensitivity Methods Using PSAT

The increase in power demand has forced the power system to operate closer to its stability limit. Voltage instability and line overloading have become challenging problems due to the strengthening of power system by various means. The nature of voltage stability can be analyzed by the production, transmission and consumption of reactive power. One of the major causes of voltage instability is the reactive power unbalancing which occurs in stressed condition of power system. And also in deregulated electricity market, it may always not be possible to dispatch all of the contracted power transactions due to congestion of the transmission corridors. The ongoing power system restructuring requires an opening of unused potentials of transmission system due to environmental, right-of-way and cost problems which are major hurdles for power transmission network expansion. So Flexible AC transmission system (FACTS) devices play an important role in improving the performance of a power system by improving the voltage profile and removing the congestion in the transmission lines, but these devices are very costly and hence need to be placed optimally in power system. FACTS device like thyristor controlled series compensator (TCSC) can be employed to reduce the flows in heavily loaded lines, resulting in a low system loss and improved stability of network. In this paper, a method based on real power performance index and reduction of total system VAR power losses has been proposed to decide the optimal location of TCSC. The effectiveness of the proposed method is demonstrated on IEEE 6-bus power system.