Comparative evaluation of modelling methods for TCSC in optimal power flow studies

This paper presents a comparative evaluation of optimal power flow analysis incorporating Thyristor controller Series compensator using both variable reactance and firing angle model. In reactance model the TCSC is modeled as a variable reactance and in firing angle model nodal admittance matrix is firing angle dependent, which then incorporated into the existing optimal power flow algorithm. The reactance value of the TCSC is taken as the state variable in the former model and the firing angle is taken as the state variable in the later model. A comparative evaluation is carried out in terms of bus voltage, angle, power flow, active power loss and power generation cost for both variable reactance model and Firing Angle model which is validated on 5 bus test system and IEEE 30 bus test system using Newton´s method.