Comparison of Voltage Stability Indices Based on Synchronized PMU Measurements

Abstract

The need for reliable information about the status of electrical power systems is an increasingly relevant concern within the current trend of electrification and deployment of power electronics-based devices. In this scenario, methods of realtime monitoring of power system long-term voltage stability using synchronized phasor measurements play an important role. This paper conducts the assessment and comparison of three well-established approaches to this issue, based solely on local measurements, in terms of different types of loads, line disconnection events, placement of monitoring devices and presence of noise in the synchronized measurements. The comparative analyses are derived from dynamic simulation data of a 3-bus test system as well as of the IEEE 9-bus network, both modelled in the open-source Python-based power system simulator DynPSSimPy. Results focus on the robustness and accuracy of each method in detecting the point of maximum power transfer, showing their advantages and drawbacks under different system conditions.