957 / 2019-04-30 21:58:08

Combining Protection Security with Post-fault Stability Assessment using a Rotor Angle Stability Index

Dynamic Stability Assessment (DSA),Protection Coordination,Protection Security Assessment (PSA),Rotor Angle Stability Index (ROI),Selectivity

Analyzes of past blackouts have shown that protection systems played a significant role. Faulty tripping of protection relays can lead to cascading tripping and wide-area interruptions of the power grid. Protection Security Assessment (PSA) is an automated and system-wide approach to simulate and assess the performance of a protection system. Running fault simulations through the system are carried out and the response of all protection relays are evaluated. Main criteria are selectivity, sensitivity and fault clearing time.
Considering those criteria, the behavior of the protections relays in Turkey, which tripped during the blackout in 2015, would be assessed as good. This case shows that the post fault behavior must not be neglected and therefore the transient stability of the whole system has to be simulated.
The proposed method is based on PSA but uses time series simulations to additionally assess the system security through a rotor angle stability index.