Voltage Stability Based on a Novel Critical Bus Identification Index

The incessant occurrence of voltage collapse which shows in either partial or total blackout due to insufficient reactive power in a power system among other factors has of recent posed a great threat and concerned to power system utilities. This paper presents a voltage collapse critical bus index (VCCBI) method for the prediction of a weak bus in a power system. First, the voltage deviation of each load bus is computed at each reactive power load variation. Next, we computed for the VCCBI of each load bus by dividing the sum of the voltage deviation at each load bus by the product of the total sum of the step size and the maximum loadability of each load bus. Comparative analysis of the suggested VCCBI method is also done with the traditional voltage collapse proximity index (VCPI) and the L-Index. Result obtained shows that the approach based on VCCBI will be of great benefits as details information as may be needed by the power system utilities for the planning and operation of the system are obtained.