Enhancing the performance of grid-connected DFIG systems using prescribed convergence law

Area of Science:

• Electrical Engineering
• Renewable Energy Systems
• Control Theory

Background:

• Wind energy conversion systems (WECS) face challenges with conventional control methods like super-twisting algorithm (STA), integral backstepping control (IBCS), and first-order sliding mode control (1-SMC) due to the chattering phenomenon.
• Doubly-fed induction generator (DFIG) based WECS require robust control for efficient power regulation.

Purpose of the Study:

• Introduce a novel high-order prescribed convergence law control (HO-PCL) strategy for WECS.
• Address limitations of existing control methods, specifically the chattering issue.
• Enhance dynamic response by improving response time and minimizing power error in active and reactive power regulation.

Main Methods:

• Development and application of the HO-PCL strategy to the rotor-side converter of a DFIG-based WECS.
• Comparative analysis using MATLAB/Simulink simulations and hardware-in-the-loop (HIL) testing.
• Performance evaluation against proportional-integral (PI) controller, 1-SMC, and IBCS.

Main Results:

• HO-PCL reduced stator current total harmonic distortion by 94.01% (vs. PI), 91.05% (vs. 1-SMC), and 85% (vs. IBCS).
• Response time was reduced by 99.25% (vs. PI), 98.96% (vs. 1-SMC), and 93% (vs. IBCS).
• Significant improvements in power ripple and overshoot were observed compared to other strategies.

Conclusions:

• The HO-PCL strategy offers a robust and effective solution for WECS control.
• It overcomes the chattering phenomenon and enhances dynamic performance.
• HO-PCL demonstrates potential for advancing control methodologies in wind power systems.