MOJTABA KHEDERZADEH - Department of Electrical Engineering, Power and Water Institute of Technology, Tehran Iran

Transient, small-signal and voltage stability are normally treated separately in a power system. This is mainly to their diverse nature. This paper describes the use of a common measure in the form of load increase to determine the proximity of small-signal instability and/or transient instability to voltage collapse. The loading at which the system reaches (or has reached) instability (transient and/or small signal), as compared with the. loading required for voltage collapse, provides a unified measure of the system stability. Results of the tests carried out on the IEEE 39 buses sample system are reported in the paper.

Voltage Stability, Small Signal Stability, Transient Stability, Dynamic Stability, Stability Index