Procedure for Real-Time Assessment of Mid- and Long-Term Voltage Stability of Electric Power Systems Operations

The present article proposes a Real-Time Operation Procedure for Mid and Long-Term Voltage Stability assessment of Electric Power Systems, which aims at determining more accurate estimates of the Voltage Stability Margin (VSM) from three different data sources: synchrophasor measurements, static, and dynamic simulations. A key aspect of the proposed procedure is the conception of two Voltage Stability Indices that establish conditions under which the static simulations no longer provide reliable results when compared to actual measurements, indicating the need to start dynamic simulations, or vice-versa. In this way, the proposed methodology establishes conditions from which it is possible to perform static simulations and achieve computational speed, without losing the precision achievable by the RMS dynamic simulations in the determination of a more realistic VSM. Numerical simulations using the Nordic Test System (an IEEE Benchmark specially tailored for voltage stability studies), show how the proposed approach is capable of providing precise value for the VSM with a significant reduction of computational burden when compared to other methodologies.