A Mathematical Model for the Scheduling of Virtual Microgrids Topology into an Active Distribution Network

Fernando García-Muñoz,Francisco Díaz-González,Cristina Corchero

doi:10.3390/app10207199

Abstract

This article presents a method based on a mathematical optimization model for the scheduling operation of a distribution network (DN). The contribution of the proposed method is that it permits the configuration and operation of a DN as a set of virtual microgrids with a high penetration level of distributed generation (DG) and battery energy storage systems (BESS). The topology of such virtual microgrids are modulated in time in response to grid failures, thus minimizing load curtailment, and maximizing local renewable resource and storage utilization as well. The formulation provides the load reduced by bus to balance the system at every hour and the global probability to present energy not supplied (ENS). Furthermore, for every bus, a flexibility load response range is considered to avoid its total load curtailment for small load reductions. The model has been constructed considering a linear version of the AC optimal power flow (OPF) constraints extended for multiple periods, and it has been tested in a modified version of the IEEE 33-bus radial distribution system considering four different scenarios of 72 h, where the global energy curtailment has been 27.9% without demand-side response (DSR) and 10.4% considering a 30% of flexibility load response. Every scenario execution takes less than a minute, making it appropriate for distribution system operational planning.

Highlights

The concept of resilience has been increasingly used in the literature related to distribution networks (DN) with high penetration levels of distributed energy resources (DER), with an interest in providing greater autonomy and flexibility in the face of unexpected power generation situations [1]
The concept of virtual microgrids (VM) with dynamic boundaries has begun to emerge as an alternative for increasing the resilience of conventional DNs [5,6] based on the IEEE Standard 1547.4 [7], which establishes that the reliability and operation of DNs can be improved by dividing the DN into multiple “isolated systems”
The sizing and location of the DERs have been separately obtained using the algorithm presented in our previous work [13], considering a connected-grid system because an autonomous network, i.e., the energy, is provided 100% by DERs; it is not a proper case of study to observe the capability of the active distribution network (ADN) to form sub-systems when the grid fails

Summary

Introduction

The concept of resilience has been increasingly used in the literature related to distribution networks (DN) with high penetration levels of distributed energy resources (DER), with an interest in providing greater autonomy and flexibility in the face of unexpected power generation situations [1]. In this context, microgrids (MG) play a relevant role in the transition process to smart grids because they offer an electrical structure that allows for improving the monitoring and management control of the renewable resources on. The work in [10] considers the paradigm of a dynamic MG as a mechanism to continuously partition a DN based on the balance between electricity generation and demand

Methods

Results

Discussion

Conclusion