Enhancing Grid-Connected DFIG’s LVRT Capability Using Dandelion Optimizer Based the Hybrid Fractional-Order PI and PI Controlled STATCOM
Abdallah Fouad, Hossam Kotb, Kareem M. AboRas, H.B. Elrefaie, Mohammed Alqarni, Abdullah M. Baqasah, Ahmed H. Yakout
Abstract
This study aims to improve the low-voltage ride-through (LVRT) capabilities of wind power plants (WPPs) during various types of grid faults, such as line-to-ground (L-G), double line-to-ground (LL-G), line-to-line (L-L), and three-phase-to-ground (LLL-G) faults. The paper proposes an enhanced cascaded Fractional-Order Proportional-Integral and Proportional-Integral (FOPI-PI)-controlled static synchronous compensator (STATCOM). The Dandelion Optimizer (DO), a novel optimization approach, is employed to fine-tune the STATCOM being studied. The DO optimizer was selected for its exceptional performance and robustness. The efficacy of the DO algorithm was assessed in comparison to three well-established methods such as the Water Cycle Approach (WCA), the Particle Swarm Optimizer (PSO), and a novel hybrid technique that combines WCA and PSO. The analysis focuses on two test systems: the 9MW wind power plant connected to an infinite bus system over a 30 km transmission line, and the IEEE 39 bus system. The results are displayed using MATLAB (R2018b) using time-domain simulation. The suggested system monitors multiple LVRT metrics, including WPP active and reactive power, voltage, and speed as well as DC link capacitor voltage. Upon conducting a comparative analysis, it was found that both the proposed cascaded (FOPI-PI) and conventional PI controller-based DO outperform other methods, such as the PI controller-based WCA algorithm, PSO optimizer, and even a combination WCA/PSO algorithm. The findings indicate that the FOPI-PI controller demonstrates superior performance compared to the PI controller. When the 9MW system has a fault, the recommended FOPI-PI controller restricts the voltage drop of the WPP to specific percentages. Specifically, the voltage drop is limited to 3% for L-G faults, 5% for L-L faults, 6% for LL-G faults, and 10% for LLL-G faults. Finally, the performance of wind power plants is much improved by adopting the proposed FOPI-PI controller optimized by DO in comparison to all other controllers in various test scenarios.