Static Security Assessment of Large Power Systems Under Contingency Cases

The rapid expansion of the power system network, increasing power demand and integration of renewable energy resources have made the power system vulnerable to outages. A power system should be in a secure state under normal and contingency conditions. An uncontrollable and cascading outage may lead to a partial or complete blackout. To avoid these catastrophic events, security assessment of N-1 and N-2 contingencies is very essential. The static security assessment (SSA) is computationally burdensome and requires a fast calculation methodology or strategies to assess the critical contingencies and appropriate remedial actions. This paper proposes a conjugate gradient method (CGM) based strategy for efficient contingency screening and ranking. The proposed method has been tested on standard IEEE-9, 118 bus system and 246 bus Northern Regional Power Grid (NRPG) network of Power Grid Corporation of India Limited (PGCIL). Results are compared with the various linear equation (LE) solver-based methods to show the computational benefits in the N-1 and N-2 SSA of the large power system.