Voltage stability indices for stability assessment: a review

ABSTRACT

Right through the past eras, behind numerous shutdowns voltage instability was the cause. Assessment of system voltage consistently ensures safe operation. Predominantly, voltage instability is caused by operating transmission line under heavy stress, deficiency in reactive power and characteristics of load at low voltages. A few methods were used in VS (voltage stability) analysis, amongst which voltage stability index calculation is more predominant one. To have a healthier understanding, this paper is concerned with the review of the key methodologies usually used to find voltage stability indices (VSI) in Potential of Electric System (PES). More than a few VSIs have been listed to compute the voltage collapse proximity, maximum loadability, voltage stability margin, identify weakest bus, contingency screening and ranking, identifying weak regions in terms of reactive power deficiency, reactive power margin, identifying and locating critical branch and areas, estimating and evaluating the system stability margin and eliminating data inconsistency in PMU measurements. More or less the indices are computationally costly, and others are told not to accomplish as estimated in all circumstances.

KEYWORDS:

• Energy systems
• power systems
• review

Disclosure statement

No potential conflict of interest was reported by the authors.