Transient stability enhancement of single machine infinite bus system

In large power system generators are requires to maintain synchronism with grid in order to provide standard service to customer utilization. Long distance AC transmission is often subjected to stability problems which affect the transmission capacity. Thyristor controlled series compensator (TCSC) is an important device in FACTS family then it is widely recognized as an effective and economical means to solve the power system stability problem. The variable impedance capability of TCSC is used as series compensator in transmission system for enhancing the transient stability. For obtaining the varying impedance, controllers based speed deviation namely bang-bang and non-linear controller are used. The simulation results show that variable impedance provides improvement in transient stability limit compared with fixed impedance TCSC. Also among the two controllers, non-linear controller provides an improving damping of power system oscillations. To validate the performance of this scheme, the simulation studies are carried out on a single machine infinite bus system using MATLAB.