Development, Analysis and Application of a Voltage Stability Index for online Monitoring

Abstract

Growing demand for electricity and the modernization of power systems in challenging markets has led to power systems running near to their stable limits. Consistent monitoring and control of power systems is therefore urgently required. Voltage stability indices help to determine the current operation of a power system, forecast potential changes to the system's existence and determine a long-term pattern of growth under predefined circumstances. A new normalized voltage stability measure called the P-index, robust and based on strong theoretical foundations, is proposed in this project then after few modifications a different voltage stability index called Q-index is proposed. Also, the generator reactive power limit is a key factor in voltage instability. When the field or armature current limit becomes active, the generator reactive power limit becomes voltage dependent. Further, careful examination of generator reactive power characteristics, reveals the effect of generator reactive power capability on system voltage stability. The analysis of application of the P-index, Q-index and implication of generator reactive limits on IEEE 14 bus system is carried out.