Practical Voltage Stability Analysis

Voltage Stability Analysis has become more important as a result of insufficient reactive resources in bulk transmission systems. Usually the objective of Voltage Stability Analysis is to identify the weak regions in terms of reactive power deficiency and determine the critical contingencies and voltage stability margins for various power transfers within regions. This paper presents a practical method to perform Voltage Stability Analysis. A Python tool developed to facilitate contingency screening and PV analysis is described. This paper also addresses issues like voltage stability criteria, cumulative errors of available voltage stability analysis tools, and identification of voltage instability regions, etc. The experiences gained by applying the method on voltage stability studies of a large power system are shared and discussed.