A new computationally efficient index for loadability limit studies

This paper presents the Load Increase Index, which is a new computationally efficient loadability limit index derived from the continuation power flow method. The continuation pouter flow is a well-known procedure for identif ying the maximum loading point of a static power system network. The propos ed index: is a byproduct of the continuation pourer flow, and may be obtain ed with little extra computational effort while yielding considerable infor mation about the distance to the critical loading point. This paper also pr esents the mathematical relationship of the proposed index to two other com monly used voltage stability indices: the smallest singular value of the lo adflow Jacobian and the determinant of the loadflow Jacobian. The proposed index: has been verified on numerous test systems of various sizes.