1. Frequency regulation in a small, isolated hybrid microgrid using decentralised control with energy storage devices.
- Author
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Mahdi, Athraa H. and Majeed, Wafaa S.
- Subjects
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ENERGY storage , *RENEWABLE energy sources , *MICROGRIDS , *SYNCHRONOUS generators , *FUEL cells , *PHOTOVOLTAIC cells , *FREQUENCY stability - Abstract
Renewable sources commonly have deficits in their momentum of inertia; thus, their increased penetration of isolated micro-grids may have a detrimental effect on frequency stability on these systems. This article thus aimed to design a decentralised control system for a microgrid equipped with static sources of renewable energy in order to adjust service levels for certain sources such as batteries, supercapacitors, and fuel cells to regulate the frequency. A microgrid was simulated to determine the initial level of inertial deficit, and the required amount of static renewable energy then sourced based on a newly proposed mathematical formula. To evaluate the effectiveness of the proposed methodology, the electric sources of the microgrid included a conventional synchronous generator, photovoltaic solar cells, and fuel cells as major sources of energy, with the batteries and supercapacitors in the system considered as support sources. The mathematical model was developed using MATLAB Simulink software in order to measure the simulated digital inertia in the system and to develop economic and environmental analyses in two primary cases: low and high penetration levels of renewable energies. The effectiveness of the proposed control system was then tested under various additional cases, with mathematical formulae used to measure the inertial deficits and the possibility of compensation. The results showed that the decentralisation approach was not limited to enabling all generation sources to provide active energy input while ensuring frequency stability, but also reduced the level of activation energy required to reach a state of stability, thus allowing all generating units work comfortably without any high electrical pressure. This work also contributed to determining the value of the inertia deficiency of the hybrid network and the amount of energy taken from energy storage devices as determined by the decentralised control circuit, a process applied to the batteries, supercapacitors, and fuel cells. This energy compensates for the inertial deficiency, thus increasing the value of the inertia constant and improving the frequency response. In case 1, with primary frequency control and inertia control, the inertia constant increased by 51% from that in the case with no controller, whereas in case 2 the increase in inertia constant was 80%. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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