Voltage stability assessment by fast time domain simulation and interior-point optimal power flow

The paper describes the use of fast time domain simulation and optimal power flow tools for voltage stability assessment, aiming at increasing the voltage stability margin of a power system for a given operating condition and network topology. First, the fast time simulator is applied to analyze the most critical contingencies that can occur in the system. Then, a modal analysis is performed in order to determine the participation factor of each generator and load in the voltage instability. These participation factors are then used to define a priority list for the optimal power flow tool to re-dispatch the active power generation and minimize the load shedding. The proposed methodology is tested on the New England test system and on a reduced system derived from the Brazilian South-Southeast system.