Sensitivity based assessment of transient voltage sags caused by rotor swings

Abstract

Abstract-The paper introduces an approach to investigate voltage sags, which are caused by large generator rotor swings following a transient disturbance. Therefore, the method exploits sensitivities derived from the algebraic network equations. These provide information on the impact of a generator on the voltage magnitude at a load bus and the effect of load variation on the generator's power injection. It is shown that these sensitivities give valuable information to identify critical generator-load pairs and locations for applying preventive control measures.

Uncertainty in real-time voltage stability assessment methods based on Thévenin equivalent due to PMU's accuracy

“…In other methods [4,5,9] the grid transformation coefficients are calculated by using the Thévenin impedance and widely used to represent the generator contribution to each Thévenin voltage as:…”

“…A family of fast assessment methods are being developed in the SOSPO 1 project [1] to achieve a secure operation of complex power systems by using realtime algorithms that rely on PMUs. A number of methods have been developed to achieve those objectives [2][3][4][5][6][7][8][9], based on fast computation of the Thévenin impedances [10] and innovative methodologies.…”

Computation of steady state nodal voltages for fast security assessment in power systems

“…It allows immediate association of contingency assessments with methods as discussed in [17] and [18] where a particular type of instability is detected on basis of Thevenin equivalents.…”

Improved Thévenin equivalent methods for real-time voltage stability assessment

“…Initiatives like NASPI 1 and SOSPO 2 [3] are examples of these efforts. This work is part of the SOSPO project, whose objective is to provide a set of fast stability assessment methods for a power system envisioned to have a high share of wind energy and other fluctuating energy sources [4][5][6][7]. In this scenario, it is foreseen that real-time applications will benefit from the availability synchrophasors technology to cope with the new challenges.…”