الفهرس 
صفحة العنوانOnly 14 pages are availabe for public view
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Abstract
ABSTRACT
Improving microgrids’ stability is a dispensable issue, especially as inverter-based renewable energy sources (RESs) become more widely used, which are distinguished by their zero-inertial response and inherently sporadic power generation. These two distinctive features can deteriorate the microgrid’s stability, especially for isolated ones. Energy storage systems (ESS), power electronics, and control approaches are used to address the stability challenges. Using a single technology of ESS with its limitations may fail to fulfill both the requirements of high-power and high-energy. Therefore, a hybrid energy storage system (HESS) made up of two different technologies is employed. This study uses the commonly used combination consisting of a supercapacitor (SC) and a battery storage system (BSS). The proposed microgrid consists of a photovoltaic generation system (PVG), a diesel generator (DG), HESS, and load. The HESS is controlled by the virtual synchronous generator controller (VSG) technique, which imitates the performance of a conventional synchronous generator.
This study is mainly divided into two parts. The first part of the study optimizes the constant parameters of the virtual synchronous generator controller (OCP-VSG) using the particle swarm optimization (PSO) technique. This technique is utilized to control the HESS, improving the frequency stability response of the proposed microgrid. The frequency response under this control technique is compared to its response under other techniques. To compare different controllers, several disturbances such as load variation, solar irradiance variation, and grid following/forming contingencies are carried out. Eventually, the first part investigates the battery storage system performance with/without the supercapacitor under different disturbances.
In the second part, the adapted inertia constant of virtual synchronous generator control based on the bang-bang technique (BB-AH-VSG) is used for the microgrid’s frequency stability enhancement and compared with CP-VSG. It also proposes an adapted inertia constant and an adapted damping coefficient of virtual synchronous generator control based on using the bang-bang technique (BB-AHD-VSG).
The adapted inertia constant (H) with constant virtual damping coefficient (D) based on the bang-bang control for the microgrid’s frequency stability enhancement is used and compared with the CP-VSG. In addition, the bang-bang control is modified to adapt the D alongside the adaptive H, and the system response is investigated and compared with the conventional adaptive H technique. To compare different controllers, several disturbances are applied to the microgrid, including load variation, solar irradiance variation, and grid following/forming contingencies.