### Abstract

In this paper, a new and generalized model for the optimal operation of microgrids is presented. The proposed mathematical model considers both operational modes, either grid-connected (GC) and islanded (IS) modes. First, a mixed integer non-linear programming (MINLP) formulation is introduced, modeling the microgrid as an unbalanced ac three-phase electrical distribution system (EDS), comprising distributed generator (DG) units, battery systems (BSs) and wind turbines (WTs). In GC mode, the frequency and the voltage magnitude references are imposed by the main grid at the point of common couple (PCC), while in IS mode, it is assumed that the DG units operate with droop control. Additionally, a set of convexification procedures are introduced in order to approximate the original MINLP model into a new convex formulation that can be solved using commercial solvers. The proposed model has been tested in a 25-bus microgrid for different scenarios, including one where a degradation of the voltage magnitude reference is observed. Results shows that the proposed model is able to properly define the operational mode of the microgrid, based on the technical constraints of the system.

Original language | English |
---|---|

Journal | I E E E Transactions on Smart Grid |

Volume | 10 |

Issue number | 5 |

Pages (from-to) | 5032-5045 |

ISSN | 1949-3053 |

DOIs | |

Publication status | Published - Sep 2019 |

### Fingerprint

### Keywords

- convex optimization
- droop control
- Energy storage
- Frequency control
- grid-connected operation
- islanded operation
- Mathematical model
- Microgrids
- optimal power flow.
- Planning
- Reactive power
- Voltage control

### Cite this

*I E E E Transactions on Smart Grid*,

*10*(5), 5032-5045. https://doi.org/10.1109/TSG.2018.2873411

}

*I E E E Transactions on Smart Grid*, vol. 10, no. 5, pp. 5032-5045. https://doi.org/10.1109/TSG.2018.2873411

**A Generalized Model for the Optimal Operation of Microgrids in Grid-Connected and Islanded Droop-Based Mode.** / Vergara, Pedro P.; Rey, Juan M.; Lopez, Juan C.; Rider, Marcos J.; da Silva, Luiz C.P.; Shaker, Hamid R.; Jorgensen, Bo N.

Research output: Contribution to journal › Journal article › Research › peer-review

TY - JOUR

T1 - A Generalized Model for the Optimal Operation of Microgrids in Grid-Connected and Islanded Droop-Based Mode

AU - Vergara, Pedro P.

AU - Rey, Juan M.

AU - Lopez, Juan C.

AU - Rider, Marcos J.

AU - da Silva, Luiz C.P.

AU - Shaker, Hamid R.

AU - Jorgensen, Bo N.

PY - 2019/9

Y1 - 2019/9

N2 - In this paper, a new and generalized model for the optimal operation of microgrids is presented. The proposed mathematical model considers both operational modes, either grid-connected (GC) and islanded (IS) modes. First, a mixed integer non-linear programming (MINLP) formulation is introduced, modeling the microgrid as an unbalanced ac three-phase electrical distribution system (EDS), comprising distributed generator (DG) units, battery systems (BSs) and wind turbines (WTs). In GC mode, the frequency and the voltage magnitude references are imposed by the main grid at the point of common couple (PCC), while in IS mode, it is assumed that the DG units operate with droop control. Additionally, a set of convexification procedures are introduced in order to approximate the original MINLP model into a new convex formulation that can be solved using commercial solvers. The proposed model has been tested in a 25-bus microgrid for different scenarios, including one where a degradation of the voltage magnitude reference is observed. Results shows that the proposed model is able to properly define the operational mode of the microgrid, based on the technical constraints of the system.

AB - In this paper, a new and generalized model for the optimal operation of microgrids is presented. The proposed mathematical model considers both operational modes, either grid-connected (GC) and islanded (IS) modes. First, a mixed integer non-linear programming (MINLP) formulation is introduced, modeling the microgrid as an unbalanced ac three-phase electrical distribution system (EDS), comprising distributed generator (DG) units, battery systems (BSs) and wind turbines (WTs). In GC mode, the frequency and the voltage magnitude references are imposed by the main grid at the point of common couple (PCC), while in IS mode, it is assumed that the DG units operate with droop control. Additionally, a set of convexification procedures are introduced in order to approximate the original MINLP model into a new convex formulation that can be solved using commercial solvers. The proposed model has been tested in a 25-bus microgrid for different scenarios, including one where a degradation of the voltage magnitude reference is observed. Results shows that the proposed model is able to properly define the operational mode of the microgrid, based on the technical constraints of the system.

KW - convex optimization

KW - droop control

KW - Energy storage

KW - Frequency control

KW - grid-connected operation

KW - islanded operation

KW - Mathematical model

KW - Microgrids

KW - optimal power flow.

KW - Planning

KW - Reactive power

KW - Voltage control

U2 - 10.1109/TSG.2018.2873411

DO - 10.1109/TSG.2018.2873411

M3 - Journal article

AN - SCOPUS:85054478476

VL - 10

SP - 5032

EP - 5045

JO - I E E E Transactions on Smart Grid

JF - I E E E Transactions on Smart Grid

SN - 1949-3053

IS - 5

ER -