LARGE-SCALE PLANNING MODELS TO ASSESS ECONOMIES OF SCALE IN DISTRIBUTION GRIDS IN THE PRESENCE OF DISTRIBUTED GENERATION

摘要

This paper proposes a method to calculate economy of scale factors in distribution networks based on the use of specifically developed large-scale distribution planning tools. Economy of scale factors are defined as the ratio between incremental distribution network costs, investment plus operational costs, and incremental demand, both increments expressed in per unit. These factors are used by regulators for setting regulated revenues to distribution companies in future years, or in prospective policy studies when the need for network infrastructures is calculated, for instance in the presence of different scenarios of penetration of distributed generation. Large-scale distribution planning models allow the computation of incremental network costs, grid reinforcement and new substations, in the presence of new customers, load growth, and new distributed generators (DG) connected to distribution grids. Network and substation expansion costs are broken down between customers and DG at each voltage level, permitting to take into account the impacts of DG within each voltage level. Economy of scale factors are calculated within a region supplied by the same company. Results of applying the developed computational method to real distribution grids with significant penetration of DG are presented and compared.