Optimal reactive power planning for load margin increase with BFO algorithm

The continuous increase in the demand of load and inadequate scope for expansion of the transmission network has leaded the power systems to operate in stressed setting. By means of the increase in loads the system operating voltage falls down and further any contingency will cause a catastrophe of voltage collapse. The voltage collapse takes place due to the lack of reactive power supply. To avoid this type of situation compensating devices can be used. These are used with optimal sizes as well as at optimal locations. Thus the operating voltage of the system improves and the load margin also increases. The work is carried out in 39- bus New England system with Bacteria Foraging optimisation technique. The optimisation technique is applied after identified weak candidate buses in the system evaluating equivalent node voltage collapse index. The objective function is based on the proposed voltage stability index which takes into account the local equivalent network, which is a simpler and faster approach than the conventional CPF algorithm. The load margin as well as the voltage profile improved with compensation with BFOA.