2023. Using Solar Photovoltaic Systems, Battery Energy Storage Systems, and Underfrequency Load-Shedding to Improve the Frequency Stability of Power Systems. Al-Rafidain Engineering Journal (AREJ). 28, 1 (Mar. 2023), 165–172. DOI:https://doi.org/10.33899/rengj.2022.136061.1201.