TCSC for Protection of Transmission Line

A grid of transmission lines operating at high or extra high voltages is required to transmit power from generating stations to load. In addition to transmission lines that carry power from source to load, modern power systems are highly interconnected for economic reasons. The large interconnected transmission networks are prone to faults due to the lightning discharges and reduce insulation strength. Changing loads and atmospheric conditions are unpredictable factors. This may cause overloading of lines due to which voltage collapse takes place. All the above said things are undesirable for secure and economic operation of a line. These problems can be eased by providing sufficient margin of working parameters and power transfer, but it is not possible due to expansion of transmission network. Still the required margin is reduced by introduction of fast dynamic control over reactive and active power by high power electronic controllers. Here my seminar explains the discussion on the effect of this device on protection of transmission line. The TCSC is considered as a dynamical device and its transient process is modelled in order to have the response to disturbances based on its own control strategy. It is shown that not only the TCSC affects the protection of its line, but also the protection of adjacent lines would experience problems. The study is done first analytically by using simple models, then the simulated results of power system and the protective relays in Real Time Digital Simulator (RTDS) are used. The results are reviewed for the study of the impact of TSCS on protection of transmission line.