Publication: Improved energy management strategy for an autonomous microgrid considering battery and partial shutdown using optimization techniques
Date
2025-03-05
Authors
Haider Jouma Touma
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Abstract
The intermittency of energy generation from renewable energy sources like solar and wind can result in the total output energy of solar Photovoltaics (PV) and Wind Turbines (WTs) exceeding the load demand. The excess energy is stored in Battery Energy Storage (BES). However, if the BES becomes fully charged, the surplus energy is dissipated via dump load to protect the BES against overcharging. One of the predominant energy management strategies (EMS) for the autonomous microgrid in the previous literature is the common rule-based EMS which often results in a significant wasted energy and requires a considerable size of dump load. Therefore, this research proposes and develops an Improved Rule-Based Energy Management System (IRB-EMS) for the autonomous microgrid, considering complementary BES and partial shutdown of WTs. The partial shutdown of WTs curbs the excess energy and as a result the wasted energy and the size of the required dump load are remarkably reduced. The complementary BES increases the entire storage capacity, hence, the Power Supply Deficiency (PSD) is noticeably reduced. Moreover, the running time of the Diesel Generator (DG) is considerably reduced, leading to a substantial decrease in fossil fuel consumption and CO2 emissions. Whale Optimization Algorithm (WOA) and Grey Wolf Optimizer (GWO) were implemented in Matlab to optimize the generation size of the autonomous microgrid. To demonstrate the feasibility of the proposed IRB-EMS, two cases of autonomous microgrids were investigated. The obtained results indicate that the proposed IRB-EMS is more feasible than the common rule-based EMS. In the first case, the proposed IRB-EMS achieved a more affordable Cost of Electricity (COE) with a value of 0.249 USD/kWh, compared to 0.287 USD/kWh for the common rule-based EMS. From a reliability perspective, the proposed IRB-EMS significantly improved the PSD to 15.1%, compared to 27.15% for the common rule-based EMS. Looking at it from an environmental standpoint, the CO2 emissions of the DG were significantly reduced to 9746.88 kg/year with the proposed IRB-EMS, as opposed to 13967.36 kg/year with the common rule-based EMS. The maximum wasted energy was reduced to 50.96 kWh with the proposed IRB-EMS, while it was 86.68 kWh with the common rule-based EMS. It's worth mentioning that similar improvements were achieved for the second case.
Description
2024