A three-stage multi-objective optimization framework for day-ahead interaction between microgrids in active distribution networks considering flexible loads and energy storage systems

Abstract

This paper provides a three-stage framework in which the microgrid strategy for participation in the electricity market is determined by considering economic, technical, and environmental indicators. In the first stage, microgrids do their day-ahead scheduling and submit offers/bids to the independent system operator (ISO). In the second stage, ISO determines the hourly market clearing price (MCP) according to the microgrids' offers/bids and finally, in the third stage, ISO solves the distribution feeder reconfiguration (DFR) problem subject to the power flow constraints. The conditional value at risk (CVaR) method is utilized to deal with uncertainties of demand and renewable energy resources (RER), and the final problem is formulated as a mixed-integer quadratic programming (MIQCP) problem. The proposed model is implemented on a 69-bus distribution system and the results show that the simultaneous presence of electrical energy storage (EES) systems and demand response (DR) program reduces the marginal prices of microgrids and consequently leads to a 19.3% reduction in MCP. The results also illustrate that the reconfigurable topology increases the ISO flexibility and thus leads to an 8.22% reduction in MCP.