Bounding method based on generalised real power distribution factors

An efficient bounding method for distribution network contingency screening is presented. It is based on the use of generalised real power distribution factors capable of modelling the effects of single and multiple topological contingencies, also including bus splits and bus joins deriving from circuit breaker operation. The proposed bounding method consists in identifying the main reclosing paths for the incremental power change. Power flow limits are evaluated for the branches belonging to an interest area centred around the contingency location. The interest area is expanded until the amount of power reclosing through not yet examined branches (boundary flow) falls under a preselected threshold value. Distribution factors are used both in branch flow limit checking and in the computation of the boundary flow. Validation of the proposed method was achieved by extensive testing on both the IEEE 118-bus network and actual systems of Italian, European and North American origin