Sensitivity Based Thevenin Index for Voltage Stability Assessment Considering N-1 Contingency

TL;DR

This paper introduces a sensitivity-based Thevenin index method for voltage stability assessment that predicts post-contingency conditions and stability margins efficiently, facilitating real-time analysis under N-1 contingencies.

Contribution

It presents a novel approach combining sensitivity analysis and Thevenin index to estimate voltage stability margins considering N-1 contingencies without requiring post-contingency data.

Findings

Accurately predicts voltage stability margins under N-1 contingencies.

Demonstrates efficiency suitable for online implementation.

Validated on IEEE 14-bus system with promising results.

Abstract

This paper proposes an approach to address the voltage stability assessment (VSA) considering N-1 contingency. The approach leverages the sensitivity based Thevenin index (STI) which involves evaluating the Jacobian matrix at current operating condition. Since the N-1 contingency case is hypothetical, there is no information regarding the operating condition after a foreseen contingency. The proposed approach first estimates the post-contingency operating point as well as possible PV-PQ transitions based on the current operating point. Then the STI for each contingency can be predicted using the estimated operating condition. Numerical results based on IEEE 14-bus system demonstrate the accuracy of the proposed approach in predicting the voltage stability margin under contingency. Moreover, the on-line implementation of the proposed approach is promising since it only involves solving several linear equations.