Further investigations on a phasor measurement-based algorithm utilized for voltage instability awareness

This paper further investigates the strengths and weaknesses of the algorithm first proposed in [1]. The algorithm estimates the Thevenin-equivalent parameters from an EHV bus. As a tutorial, the paper assesses the performance of the algorithm applied to a very simple electric circuit. The performance of the algorithm is compared to a recursive least square algorithm with noisy measurements. At the end, the algorithm is applied to a long-term voltage instability scenario and to a marginally stable scenario in the Nordic 32 benchmark system.