Reliability of islanded microgrids with stochastic generation and prioritized load

Abstract

The potential to improve distribution system reliability is a primary motivation behind the development and deployment of microgrids. Previous studies have illustrated substantial reliability benefits of dispatchable distributed energy resources (DER). However, more analysis and new evaluation methodologies are needed for microgrids dominated by limited and stochastic distributed generation (SDG). The present paper introduces an evaluation methodology for islanded microgrids that realistically represents stochastic resources and explicitly examines the influence of supply-to-load correlation on reliability. Monte-Carlo simulation is used to model component failure and repair, while historical data is used for the stochastic resource. SDG output is allocated to loads based on a prioritized order that accounts for the dynamic reconfiguration of the microgrid in the case of a local fault. Voluntary load curtailment and its impact on reliability are also examined. Simulation results reveal that the priority order of a given load section on an islanded microgrid with limited SDG determines its dominant cause of interruption and has a major influence on reliability.