Artificial intelligence approach to load allocation in distribution substations

Abstract

Based on the set theory and the Prolog programming language, the paper develops methods by which the allocation of loads to the busbars of distribution substations may be determined automatically. Starting from the initial possible allocation of loads to the substation busbar sections, a formulation for load allocation is first developed using set theory. The 'generate evaluate and test' technique and the depth-first search method are then applied to the solution-seeking process. The formulation is implemented and recursive search procedures are derived using the Prolog language. The Prolog software aid developed includes a complete solution generator from which all hypothetical solutions are generated, an evaluator which prunes invalid solutions, and a tester which produces feasible solutions by checking the load allocation constraints related to the firm capacity of the distribution substations. An application of the methods developed is given for two 11 kV interconnected substations which include 5 busbar sections and 10 ring loads. List of principal symbols Symbols in formulationB t = set containing ring loads which may be allocated to busbar section i C, = set containing ring loads which may be allocated to busbar section i and to other busbar sections S t = set containing ring loads which can only be allocated to busbar section i Ri = set containing ring loads which have been allocated to busbar sections j , where; # i p. = power set of a set that contains ring loads which are allocated to busbar section i £, = set containing ring loads which are allocated to busbar section i Qi = set containing all the sets each of which contains all the ring loads that have been allocated to busbar section i A { = set containing ring loads which are to be allocated to busbar section i Symbols for variables in Prolog clauses Ring_id = ring identifier Paper 5528C (P9, C4),

Power distribution planning: a review of models and issues

“…Wong and Cheung (1987) listed several AIExpert system for various power-system applications. They presented a set theory based formulation for load allocation in distribution substation.…”

Models and Procedures for Electric Energy Distribution Planning. A Review

“…In the reviewed papers from the last years, there is a tendency to use evolutionary algorithms [Bouchard et al 1994, Lin et al 1998, Miranda et al 1994, Ramírez-Rosado, Bernal-Agustin 1998, Neimane, Andersson 1999, Skrlec 1996 and expert systems [Chen, Hsu 1989, Hsu, Chen 1990, Wong, Cheung 1987, Dueire, Carvalho 1996, Tumazos 1997] as solution procedures, obtain which have achieved good results with these techniques. Table I is presented as an annex, there the characteristics of each reviewed work is shown.…”

Applications of artificial intelligence and expert systems in power engineering

“…The allocation schemes are normally derived by the operators manually. To assist the operators in solving these allocation problems, a software system developed based on artificial intelligence techniques for allocating loads in distribution substations and a computational algorithm using the best-first search strategy for allocating circuits in subtransmission substations were developed by Wong & Cheung (1987. This work is outlined in the following sections.…”