A two-level model to define the energy procurement contract and daily operation schedule of microgrids

Abstract

A two-level energy management model that integrates energy procurement contract, operation scheduling under uncertainty, and demand response for connected microgrids is presented in this paper. It provides a framework for managing microgrid operations efficiently by prioritizing renewable over non-renewable generation. In this way, it is possible to size/measure both battery system and diesel generators reserves for overcoming forecast errors of both renewable generation and non-deferrable load demand; and this also enables deferrable load managing. A flexible chance-constraints-based mathematical programming model is also proposed, which can be used as an optimization model at both levels of the energy management model for defining an optimal energy procurement contract based on energy market trade policies and for generating an optimal daily operation schedule based on the energy contract. Furthermore, a new criterion for chance-constraints modeling based on historical minimum/maximum values is proposed. This modeling is intended to consider a high percentage of potential scenarios that may take place during execution. The percentage of presumed cases is estimated from simulation results.