Impact of TCSC on measured impedance by MHO distance relay on 400 kV Algerian transmission line in presence of phase to earth fault

Abstract EN

This paper presents a study on the performances of distance relays setting in high voltage 400 kV in Eastern Algerian transmission networks at Sonelgaz Group (Algerian Company of Electricity and Gas) compensated by series Flexible AC.

Transmission System (FACTS) i.e Thyristor Controlled Series Capacitor (TCSC).

The facts are used for controlling transmission voltage, power flow, reactive power, and damping of power system oscillations in high power transfer levels.

The direct impacts of TCSC insertion on the total impedance of a protected transmission line (ZAB) and measured impedance (Zseen) by MHO distance relay are investigated in presence of phase to earth fault with fault resistance (RF) varied between 0 to 100 Ω.

The modified parameters of the protected transmission line have been calculated in order to improve the performances of distance relay protection to prevent circuit breaker nuisance tripping.

The simulation results performed in MATLAB software show the direct impact of TCSC when inserted in the midline transmission line on the measured impedance.

More, the effects of the RF and injected voltage VTCSC on the short-circuit calculation parameters and Zseen are presented.