Islanding and Resynchronization Procedure of a University Campus Microgrid

Abstract

During the last decade, microgrids are attracting a significant attention due to their numerous advantages. Amongst them, the most important one is their ability to operate either in grid-connected or in islanded (autonomous) mode. However, the transition between the two modes can be challenging in terms of maintaining the stability and integrity of the microgrid. In this paper, an optimization-based islanding methodology is developed to ensure a timely and smooth transition from the grid-connected to the islanded mode. This is achieved through shedding loads, by defining the generation level of the photovoltaics (energy spill) and by regulating the charging/discharging rate of batteries. A resynchronization method is also presented along with the requirements that need to be satisfied for the smooth reconnection of the microgrid back to the main grid. The effectiveness of the proposed approach is demonstrated through simulation results for the events of surplus energy production, and excess energy demand of the microgrid.

Optimal Energy Management and Scheduling of a Microgrid in Grid-Connected and Islanded Modes

“…The primary and secondary control levels consider droop controls and coordination methods respectively [5]. Examples of novel secondary controller methodologies responsible for ensuring the stable operation and the smooth transition of the microgrid between the grid-connected and islanded modes are proposed in [6] and [7], respectively. Tertiary control level represents the microgrid's highest control level and it is responsible for managing its power flows in order to maintain an economically optimal operation of the system [8].…”

“…Note that the proposed scheduling algorithm will be executed every time the microgrid changes mode (grid-connected or islanded) in order to identify the optimal energy management for the system. In the meantime, the method presented in [7] will ensure a smooth transition and it will keep the system stable until the proposed scheme applies all the necessary modifications.…”

Microgrid Application in Algeria Saharian Remote Areas

“…The microgrid system is modelled first in Matlab/Simulink/SimPowerSystems software, and then it will be compiled with the e-MEGAsim simulation of the RT-LAB platform [2,6,7], which improves the simulation of increasingly large systems with real-time performance on multiple CPUs (Figures 13 and 14).…”

“…On the other hand, winds in the same area are frequent and strong. Rainfall is distributed in irregular manner along the year [1,2].…”

Resilient and Immune by Design Microgrids Using Solid State Transformers

“…The possibility of mitigating on short to medium term a match between production and consumption during the post-disconnection moment (when starting to work in islanding operation mode) are discussed in recent works [33]. In this case, the under investigation micro-grid was considering a diesel generator as a master in order to keep the stability of the microgrid while the photovoltaic (PV) and storage was in a grid or generator follower mode.…”