A New Planning Model for Distribution Systems

This work presents an efficient algorithm for the static investment planning of large radial distribution systems. It takes into account the fixed costs, concave nonlinearities in the cost functions of all elements and the operational constraints. A concave fixed cost model is used to represent elements with large fixed costs (substations and possibly some feeders) and linear cost functions are assumed for the remaining elements. A branch and bound algorithm is used with bounding criteria dependent on the cost and operational constraints. The fixed costs of the remaining elements is then accounted for through an iterative procedure which modifies the solution of the first step. The validity and efficiency of the model have been tested against published results. Results for a large rural radial system are presented.