Journals Proceedings

Abstract

To meet an ever-increasing electrical load demand, modern power systems are undergoing numerous changes and becoming more complex from operation, control and stability maintenance standpoints. The major problem that is associated with such a stressed system is voltage instability or collapse. A system is said to enter a state of voltage instability when a disturbance causes a progressive and uncontrollable decline in voltage, which can occur because of the inability of the network to meet the increased demand for reactive power. Therefore, the voltage stability analysis is essential in order to identify the critical buses in a power system i.e., buses which are close to their voltage stability limits and thus enable certain measures to be taken by the operators in order to avoid any incidence of voltage collapse. Based on the basic understanding of voltage collapse and voltage stability analysis, a new index of analyzing static stability is proposed utilizing the power flow solution based on the transmission line impedance and the apparent power at the receiving end. The proposed line stability index has the capability to identify the weakest bus and the weakest line in the interconnected power. Simulations were carried out to validate the proposed index using Western System Coordinate Council (WSCC) 9-bus test system. The results are presented and compared with indices found in literature.