Heuristic methods for the optimisation of MV distribution networks operation and planning

Most MV power distribution networks are normally operated radially. However, more or less, there are always interconnecting facilities between adjacent feeders of the same or neighboring HV/MV substations. The facilities of modern distribution control centres enable the maximum exploitation of the existing MV networks by proper selection of their configuration. An effective reconfiguration strategy takes advantage of the behaviour of the loads and has two main targets: (i) to reduce the power system energy losses; and (ii) to relieve the overloads in the network by 'load balancing'. Other optimisation criteria can also be applied. Moreover the problem of optimal expansion planning can be considered as the selection of network configurations, for successive years, that minimises the total cost (investments, losses, etc.) during the study period while satisfying operational constraints. Because of the complexity of MV distribution networks, heuristic methods are the most suitable for this problem. In this paper, an heuristic method for optimum expansion planning and the relevant software is presented and applied in a typical 20 kV distribution network.