Diagnosis Tools

Voltage Collapse Contingency Selection *More*

VCCS searches for single and double contingencies with a predisposition to either producing cascading voltage instability or local voltage instability by simulating a set of 500,000-1,000,000. It then determines those equipment outages that have no solution using snapsnots approximating a quasi dynamic simulation followed by a four step diagnostic for separating voltage instability and loadflow convergence for each simulated contingency. *More*

Contingency Vulnerable Areas / Loadpockets *More*

CVA determines all subnetworks within a given region of interest and buffer zone that can experience voltage instability. All areas composed of subsets of subnetworks that can experience cascading voltage instability are also identified. The subset of these areas that experience voltage instability for contingencies identified by VCCS are also determined and are called loadpockets. The contingencies that produce voltage instability in each loadpocket are also identified. *More*

Voltage Collapse Propagation and Protection Assessment *More*

Branches with emergency thermal limit violations and buses with emergency voltage limit violations at the point of non-solution can indicate potential branch and generator outage contingencies that would propagate the voltage instability for contingencies that have no dynamic simulation approximation. Buses with significant voltage decline at the Boundary Case Solution for these CVVS contingencies indicate critical voltage levels that warn of cascading voltage instability, motor protection actions, Under Voltage Load Shedding actions, and generator protection actions. The critical voltages at the point of non-solution are needed for design of protection controls. *More*

Voltage and Thermal Security Assessment *More*

Determines single and double equipment outages with thermal and /or voltage limit violations for the 500,000 1,000,000 outages that solved or are close to voltage instability to determine those that have thermal limit and voltage limit violations. These contingencies are reported in a MUST Table for preventive actions to relieve these security violations. *More*