A direct method for assessment of overall voltage condition of power system

• Reduction in voltage raises the line losses, thus depressing the bus voltage.
• Tracking weak bus voltages not always give the actual voltage stability condition.
• Monitoring overall power mismatch, the voltage condition of system can be monitored.
• Improper utilization/placing of VAR sources draw system closer to voltage collapse.

One of the reason of stressed power system being driven to voltage instability is the inverse relation between voltage and change in transmission line series loss. This work develops a technique for determining voltage stability of the system employing transmission line loss of a system. The equivalent two-bus model of network is used for assessing the voltage condition of the network. The main feature of technique is to avoid monitoring of individual buses or branches to assess the voltage stability. The objective of the work is to consider the total generation and total demand data available in the control center to predict the overall voltage stability of the system and thus it is suitable for real-time monitoring. The proposed voltage stability monitoring approach has been validated using IEEE 30 bus and Indian Utility 62 bus test system for different practical conditions.