A New Analytical Method for Optimal Sizing and Sitting of Type-IV DG in an Unbalanced Distribution System Considering Power Loss Minimization

This paper presents a new analytical method which is derived from a basic power flow equation and then modified for an unbalanced feeder for optimal sizing and sitting of Type-IV DG (A DG which supply active power and in return consume reactive power) at a large scale in an unbalanced distribution system. Introducing a DG that requires reactive power possesses some serious concern with power quality and this situation becomes more venerable when DG is connected in an unbalanced feeder. This is done by identifying the power loss at each node and a new power economy factor which represents exact power loss formulae in terms of economy is formulated for unbalanced feeders considering power loss minimization technique. Further, it is then minimized to acquire the optimal sizing and sitting of DG. For validating the results, IEEE 34 and 123 bus systems unbalanced system was used and it has been found that the proposed method shows significant power loss reduction in the distribution system.