Alternative investment strategies for improving distribution system reliability by using representative networks

The regulation of distribution network monopolies has been shifted from asset-based to performance-based, and continues to encourage performance improvement in terms of quality of service provided to customers. In addition to improving the quality of service, such a shift should be carried out in a cost-effective way. In order to achieve this, a general methodology is needed to compare the reliability performance with alternative investment strategies. Therefore, the last years have witnessed increasing interest towards development of analysis capability and tools that enables to adequately assess network performance and to evaluate benefits of alternative distribution network investment strategies. The enormous diversity of topologies, customer densities, and protection levels of the feeders in real distribution systems has been a major obstacle for strategic planning activities. In order to simplify the decision-making processes needed for distribution network planning, a specific model has been previously implemented. Within this model, a large number of real feeders are grouped by similar characteristics into a simplified network. More specifically, so-called Representative Networks (RNs) are calculated using easily manageable and accessible high-level information that is extracted from real feeders´ databases reflecting reliability performance of group of real feeders with a great accuracy. This work illustrates how RNs can be used to assess the impact that performance-driven investment strategies will have in terms of reliability improvement at a strategic level. The representative network parameters are quantified based on the different investment scenarios (or a combination of investment scenarios). The methodology has been validated using real data from several Distribution Network Operators.