Design of Fuzzy Coordinated PI Controller for Supercapacitor in Large Scale Wind Farm

This paper presents a controller using fuzzy coordinated PI for improving the dynamic performance of supercapacitor (SC) coupled to doubly fed induction generator (DFIG) through a buck-boost converter (DC-DC converter) during disturbances in large scale wind farm. The DC-DC converter is connected at the DC-link of the back-to-back converter of DFIG. The main objective of this study is to improve the performance of SC storage technology with fuzzy tuned PI supervision rather than traditional control. It aims to meet the expectations of various scenarios for a wind speed function and different types of system faults, to keep stable the DC bus voltage and output power. This paper studies single-phase, double-phase, and three-phase faults, and studies the effect of the fault duration and location. The paper also studies different function types of wind speed variation such as real, extreme, and step-change wind speed. The results of fuzzy coordinated PI control are compared with classic PI control. This comparison shows that fuzzy PI controller performed better than the PI controller.