Performance enhancement using terminal synergetic approach-based back-to-back converter current control for grid connected PMVG wind energy conversion system under diverse operating conditions

This study presents a terminal synergetic approach-based current control scheme for power converters in grid-connected permanent magnet vernier generator-based wind energy conversion systems. Traditional wind energy conversion system converter current control strategies encounter challenges related to slow convergence, chattering, susceptibility to mismatched system parameters, and sudden input perturbations that severely impact the desired control response. To address this, an integral-type terminal synergetic current control is proposed with a modified macro variable to ensure a better dynamic response. The modified macro variable in the proposed integral-type terminal synergetic current control augments the convergence rate of the steady-state error to zero and derives a chattering-free smooth dq-axes output voltages. Additionally, an integral-adaptive mismatched disturbance observer is integrated into the control scheme to accurately attenuate uncertain disturbances, leading to significant reductions in grid current harmonics and permanent magnet vernier generator torque pulsations. Also, the appropriate Lyapunov function is utilized to derive and guarantee the stability conditions of the presented integral-type terminal synergetic current control. Finally, the proposed scheme is verified in a 5 kW permanent magnet vernier generator-based wind energy conversion system simulation and laboratory experimental prototype. Besides, the effectiveness of the presented integral-type terminal synergetic current control over the existing PI and sliding mode approaches is verified through simulation and experimental comparative results.