Analytically Exact Distributed Voltage Stability Index based on Power Flow Circles
share
The real-time monitoring of long-term voltage stability is the key to wide-area monitoring, protecting and control applications. Although centralized monitoring methods are exact and accurate, they are unscalable, calling for decentralized methods. Unfortunately, current decentralized algorithms are accompanied by approximation errors. Solving this problem, we propose a new distributed voltage stability index (VSI) pertaining to both accuracy and scalability. Specifically, the proposed VSI is calculated at each bus locally only using communication between phasor measurement units (PMUs) at the neighboring buses. In addition to providing VSI at different loading conditions, the newVSI also features the ability for fair comparison at zero loading condition, so that the system operator can identify the most critical bus induced by network topology and branch admittance values. As a byproduct, the VSI can identify the line outage location. The effectiveness of the proposed index is demonstrated successfully with IEEE test systems.
READ FULL TEXT