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 power flow is a well-known procedure for identifying the maximum loading point of a static power system network. The proposed index is a byproduct of the continuation power flow, and may be obtained with little extra computational effort while yielding considerable information about the distance to the critical loading point. This paper also presents the mathematical relationship of the proposed index to two other commonly used voltage stability indices: the smallest singular value of the loadflow Jacobian and the determinant of the loadflow Jacobian. The proposed index has been verified on numerous test systems of various sizes