Reconfiguration of radial distribution networks: application of heuristic methods on large-scale networks

Heuristic methods for the reconfiguration of radial distribution networks have been presented by several researchers. The objective of the studies involved is either to minimise resistive line losses during normal operation, or to balance load and relief overloads, e.g. during service restoration procedures. In the paper the two basic strategies employed and the adequate methods developed for both objectives are presented, improved and generalised. An efficient approach to the load balancing problem, using switch exchange operations, is presented. An overall algorithm for the reduction of the size of the network model without decreasing computations accuracy of all methods is also presented. The adequate computer programs are applied on a real, large-scale 20 kV Greek network, for the optimisation of its operation under normal operating conditions and after the occurrence of an outage. General conclusions are drawn regarding the comparison of the two strategies as modelled in the paper and the opportunities network reconfiguration offers for operation improvement