Utility-owned DG units´ impacts on distribution system operation

This paper presents a new paradigm for distribution system operation in the presence of utility-owned distributed generation (DG) sources. The paper proposes the concept of goodness factors for DG units, based on a computation of incremental contribution of DG units to system losses. The incremental contributions of a DG unit to active and reactive power losses in the distribution system are termed as the active/reactive incremental loss indices (ILI). The goodness factors are integrated directly into the distribution system operations model, which is based on an optimal power flow (OPF) framework. This model seeks to minimize the distribution company´s (disco´s) energy costs in the short term taking into account the goodness factor of each DG unit. The disco is assumed to be owner of the DG units and hence is responsible for their scheduling and dispatch. Analysis was carried out considering an 18-bus distribution network extracted from the well-known IEEE-30 bus system.