Abstract
This article presents several innovative methods to mitigate frequency deviations in hybrid renewable power grids (HRPGs) with high penetration of renewable energy sources (RESs). Two models of the HRPGs are considered: the first model is a two-area power grid that combines three conventional power plants and two RESs in each area, while the second model is the IEEE 39-bus system. The tie-line is connected in series with a unified power flow controller (UPFC). The first method introduces an approach in the secondary control loop (SCL), where a fuzzy logic controller is cascaded with an Integral-Tilt-Derivative (I-TD) controller (Fuzzy I-TD). Additionally, the performance of the Fuzzy I-TD controller is compared with other approaches, such as Fuzzy Proportional-Integral-Derivative (Fuzzy-PID) and Fuzzy Integral-Proportional-Derivative (Fuzzy I-PD). The second strategy integrates the Fuzzy I-TD controller in the SCL along with controlled energy storage systems (ESSs), such as plug-in electric vehicles (PEVs). The parameters of the strategies are optimized using a recent metaheuristic algorithm known as the Sea Horse Optimizer (SHO) under different operating conditions. A comprehensive investigation is conducted to validate the effectiveness of the Fuzzy I-TD controller and the Fuzzy I-TD controller with PEVs in HRPGs. The Fuzzy I-TD controller significantly reduces frequency and tie-line deviations in the SCL by 82.7% and 97.01%, respectively, when compared to the Fuzzy I-PD and Fuzzy-PID controllers. Moreover, the Fuzzy I-TD with PEVs reduces frequency fluctuations by 40% compared to the Fuzzy I-TD alone in the SCL. The results demonstrate that the presented strategy is efficient and effective for HRPGs.