A novel approach for load margin improvement with optimal location and size of static capacitor using BFO algorithm

Power systems are forced to operate under stressed condition because of continuous increase in load as well as constraints of network expansion and generations. This can lead to voltage instability when it faces further load increase or any contingency in the form of line outage or generator outage. In order to avoid voltage instability VAR compensating devices are employed. These are at optimal location and of optimal size which improve the load margin. This work aims at obtaining optimal size as well as location of compensation in the 39-bus New England system with the help of Bacteria Foraging optimisation and Genetic algorithms. To reduce the computational time the work identifies weak candidate buses in the system, and then picks only two of them to take part in the optimization. The objective function is based on a recently proposed voltage stability index which takes into account the weighted average sensitivity index is a simpler and faster approach than the conventional CPF algorithm. BFA has been found to give better results compared to GA.