2004 Cigre SCB5 Session Preferential Subject 3 Question 8a Torbjörn Einarsson ABB Sweden

SC B5: PS3, Q 8a How to optimize settings? What methodologies are used to optimize settings for series compensated line application? REAL TIME SIMULATIONS!

Why real time simulations? Real time simulations are very useful tool for the setting verification process Series compensated networks are normally very complicated Analytical method more time consuming Difficult to cover all combinations of fault conditions and the interactions between IED`s and power system when using analytical methods Difficult to foresee all the dynamic behavior when doing the setting calculations Voltage inversion, might cause directionality problem Sub-synchronous oscillations, might cause overreach Verifying the total protection scheme Very good learning process

Example of series compensated network 200 km 130 kV SC 300 km 400 kV 250 km 100 km 400 km 170 km P P 120 km 130 kV 130 kV 130 kV 350 km Equivalent source 130 kV SC Shunt compensator Three-winding power transformer SC Two-winding power transformer Series capacitor with over-voltage protection Shunt reactor P Line protection under test