This research work proposes a modified sine cosine algorithm (mSCA) to optimize the parameters of a multistage fractional-order PD-PI (MSFOPD-PI) controller for load frequency control of an isolated AC microgrid. Microgrid considered here is a cluster of renewable energy sources like photovoltaic (PV), wind turbine generators (WTG) which diverges from their optimal operating point due to change in its environment. Initially, the performance of proposed mSCA algorithms is compared with the original sine cosine algorithm (CSA) well as other techniques like Crow search algorithm (CSA), Artificial bee colony (ABC), Cuckoo Search (CS), Gravitational search algorithm (GSA), Dragonfly (DA) and Genetic algorithm (GA) techniques using benchmark test functions reported in the literature. In the next stage, proposed mSCA is applied to optimize MS FOPD-PI controller parameters under different fluctuating scenarios of source and load. To demonstrate the supremacy of the proposed MS FOPD-PI controller the performances are compared with conventional PID, PI and I controllers. A sensitivity analysis is made by varying the system parameters to justify the controller's robustness.

中文翻译：

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改进正弦余弦优化多级FOPD-PI控制器用于孤岛微电网系统负载频率控制的性能分析

这项研究工作提出了一种改进的正弦余弦算法 (mSCA)，以优化多级分数阶 PD-PI (MSFOPD-PI) 控制器的参数，用于隔离交流微电网的负载频率控制。这里考虑的微电网是一组可再生能源，如光伏 (PV)、风力涡轮发电机 (WTG)，由于环境的变化而偏离其最佳运行点。首先，将提出的 mSCA 算法的性能与原始正弦余弦算法 (CSA) 以及其他技术，如 Crow 搜索算法 (CSA)、人工蜂群 (ABC)、布谷鸟搜索 (CS)、引力搜索算法 (GSA) 进行比较、蜻蜓 (DA) 和遗传算法 (GA) 技术使用文献中报告的基准测试函数。在下一阶段，提出的 mSCA 用于在不同的源和负载波动情况下优化 MS FOPD-PI 控制器参数。为了证明所提出的 MS FOPD-PI 控制器的优越性，将性能与传统的 PID、PI 和 I 控制器进行了比较。通过改变系统参数来进行灵敏度分析，以证明控制器的稳健性。