Hybrid PI–modified-super-twisting control for DFIG wind turbine power converters

Abstract

This work aims to control the DFIG-based wind turbine conversion system by proposing an advanced control scheme for both the rotor-side and grid-side power converters to control power flow, maintain DC-link voltage stability, and enhance current quality. The proposed approach combines PI control with a modified super-twisting controller based on a smooth tangent hyperbolic. A PID-type sliding surface is introduced to improve robustness while further reducing chattering effects. The reference active power is generated by a mechanical control system using a PI controller applied to the turbine rotational speed. The stability of the system is analytically studied by using Lyapunov theory. To prove the effectiveness of the proposed control strategy, comparisons with other control techniques reported in the literature are carried out under various operating conditions. Simulation results obtained using MATLAB/Simulink confirm the improved performance and the effectiveness of the proposed approach.