ON-LINE VOLTAGE STABILITY ASSESSMENT OF POWER SYSTEMS-BLACK BOX MODELING APPROACH

The management of power systems has become more difficult than earlier because power systems are operated closer to security limits, environmental constraints restrict the expansion of transmission network, the need for long distance power transfers has increased and fewer operators are engaged in the supervision and operation of power systems. Voltage instability has become a major concern in many power systems and many blackouts have been reported, where the reason has been voltage instability.