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- Beyene, Yared Bekele, et al.
(författare)
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On the design and optimization of distributed energy resources for sustainable grid-integrated microgrid in Ethiopia
- 2023
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 48:78, s. 30282-30298
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a study that focuses on alleviating the impacts of grid outages in Ethiopia. To deal with grid outages, most industrial customers utilize backup diesel generators (DG) which are environmentally unfriendly and economically not viable. Grid integration of hybrid renewable energy systems (HRES) might be a possible solution to enhance grid reliability and reduce environmental and economic impacts of utilizing DG. In this study, an optimization of grid integrated HRES is carried out for different dispatch and control strategies. The optimal power supply option is determined by performing comparative analysis of the different configurations of grid integrated HRES. The result of the study shows that grid integrated HRES consisting of photovoltaic and wind turbine as renewable energy sources, and battery and hydrogen as hybrid energy storage systems is found to be the optimal system to supply the load demand. From the hydrogen produced on-site, the FC generator and FCEVs consume 143 620 kg/yr of hydrogen which is equivalent to 394 955 kg/yr gasoline fuel consumption. This corresponds to saving 1 184 865 kg/yr of CO2 emissions and 605 703 $/yr revenue. Besides, this system yields 547 035.4 $/yr revenue by injecting excess electricity to the grid. The study clearly shows the economic and environmental viability of this new technology for implementation.& COPY; 2023 The Author(s). Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC. This is an open access article under the CC BY license (http://creativecommons.org/ licenses/by/4.0/).
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| 2. |
- Beyene, Yared Bekele, et al.
(författare)
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On Virtual Complex Impedance Droop Control of VSC-Based Islanded Microgrids
- 2023
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Ingår i: Proceedings of 2023 IEEE PES Innovative Smart Grid Technologies Europe, ISGT EUROPE 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- This paper investigates the droop control techniques used to ascertain the proper sharing of active and reactive power of multiple VSCs in an islanded microgrid. The dynamic model of the system control loops is performed in a dq rotating reference frame. The droop control loop is analyzed, taking into account the inductive nature of the output impedance of the microgrid due to the inductor of the filter and coupling inductor. To minimize the circulating current that flows between parallel VSC, a virtual complex impedance loop is included in the proposed controller. In order to avoid the stability problem occurring at the resonant frequency of the LCL filter, a parallel resistor is added to the LCL filter capacitor. For both equal and proportional power-sharing strategies, the proposed controller can achieve accurate power-sharing with an excellent dynamic performance of the system. The simulation results are presented to reveal the accurate performance of the proposed controller.
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