The Voltage Collapse Problem Based On The Power System Loadability

Abstract

This paper addresses the problem of voltage instability at which the power system reaches its maximum admissible load. A voltage collapse proximity indicator (VCPI) is derived and its performance is investigated. The VCPI is the ratio of the system equivalent impedance to the load equivalent impedance. In this paper, an algorithm for network equivalent impedance is proposed; it employs the PV-PQ sensitivity and "referencing" techniques to determine an equivalent impedance of a multi-machine multi-node power system. The validity and effectiveness of this method is demonstrated with the application of different network configurations ranging from the standard IEEE 14-bus to the realistic 116-bus Qatar power system.