Designing reliable and resilient smart low-voltage grids

Abstract

The electric power grid is a critical infrastructure that delivers electricity from power generation sources to consumers. At this time, renewable and distributed sources of electricity as well as new technologies that introduce large loads are significantly changing load profiles in low-voltage grids. This trend calls for reassessing the structure of low-voltage grids to examine if they can safely accommodate the new load profiles. The future smart grid will also rely on information and communications networks to support decentralized power distribution. The information and communications network nodes may depend on the grid for power supply, leading to bidirectional interdependence between the two types of networks that could affect the reliability of the power grid.This paper focuses on the problem of enhancing the reliability of future low-voltage grids by improving their structure and dealing with their interdependence with information and communications networks. The paper investigates the structural features of a low-voltage grid and assesses their influence on the ability of the grid to handle new load profiles. Concepts from complex networks theory are used to derive relevant structural metrics that characterize the structural properties of low-voltage grids and performance metrics are proposed to assess their operational performance. Several low-voltage networks are analyzed under various loading scenarios to observe the influence of structural metrics of a low-voltage grid on its operational metrics. Based on this analysis, a constraint programming formulation is proposed for the cost-optimal and robust structural design of a low-voltage grid. In addition, a design algorithm is proposed that considers the interdependence of information and communications network nodes on power grid nodes to increase the reliability of the grid.