Comparative Analysis of PMU Based Corridor Voltage Stability Indices and Enhanced Approach

This paper provides the comparative analysis including concepts, validation and limitations of four different synchrophasor measurement based corridor voltage stability indices (VSI) namely: a) Thevenin based equivalent, b) Area Equivalent, c) Power Equivalent and d) Radial Equivalent and Independent (REI) equivalent. To validate these four approaches, continuation power flow solutions are used as a benchmark and equivalent 2-port network is developed for the corridor buses. Moreover, a threshold methodology is proposed for Area, Power and REI based equivalents to facilitate better operator awareness. An enhanced algorithm is proposed to take into account impact of nearest Q-limits for hybrid approach using measurement from phasor measurement units (PMUs) and minimal model information for corridor VSI.