A new algorithm for fault location in series compensated transmission lines with TCSC

• Compensated transmission lines with Thyristor Controlled Series Capacitor (TCSC).
• Time domain modeling of a transmission line and the TCSC.
• Fault section identification in series compensated transmission lines.
• Fault location estimation in series compensated transmission lines.

In this paper a new algorithm for accurate fault location in advanced series compensated transmission lines with Thyristor Controlled Series Capacitor (TCSC) is presented. Time domain modeling of a transmission line and the TCSC system are used in the proposed algorithm. This algorithm consists of two subroutines considering faults in the line sections i.e. in front of TCSC and behind it. Subroutines selection in the algorithm is performed by using a parameter known as the Fault Section Indicator (FSI). FSI is, in fact, the virtual resistance of the TCSC measured during the first cycle of fault inception. The one-cycle FSI trend indicates the faulty section, and an accurate method is adopted for fault location estimation. Extensive simulations were carried out using ATP-EMTP software on a 400 kV, 300 km transmission system with the TCSC installed in the middle of the line. The results confirm the capability of the FSI parameter for correct identification of faulty section and the accuracy of the proposed fault location algorithm.