Introducing a new index to investigate voltage stability of power systems under actual operating conditions

Voltage stability is one of the most important issues in power systems. Voltage collapse is a problem that occurs in heavily loaded power systems. To prevent voltage collapse in power networks, a relatively accurate estimation of system operating conditions is necessary. A new voltage stability index is presented in this paper based on the P-V curve analysis. Mathematical equations of P-V curves are extracted and the proposed Power System Voltage Stability Index (PSVSI) is defined based on the distance between the operating point and saddle point on the P-V curve. The performance of the proposed voltage stability index is compared with the most important voltage stability indices in different power system conditions. Moreover, voltage stability margin is detected by using the modal analysis method to evaluate the obtained results.