Three-phase instantaneous current control of grid-forming wind turbines generators with fault ride-through capability

• Difference equation-based controller enables phase-independent converter control. • Simple parameter design and decoupled control loops enhance engineering practicality. • Enhanced dynamic performance with high robustness against disturbances is achieved. • Phase-decoupled virtual impedance handles both symmetrical/asymmetrical faults. The grid-forming wind turbine generator exhibits synchronous voltage source characteristics, enabling grid voltage construction and frequency regulation. However, coupled control loops lead to degraded dynamic performance, even severely impacting the stability of renewable energy integration systems. To improve the performance mentioned above, a three-phase instantaneous current control method with fault ride-through capability for the grid-forming wind turbine generator is proposed. First, a system of the permanent magnet direct-drive wind turbine generator integrated into a weak grid with the traditional control method is introduced. Next, the three-phase instantaneous current control method with fault ride-through capability is proposed, incorporating a discrete-time control based on difference equations, virtual impedance control via decoupled per-phase compensation, and transient active power control by means of the grid-side converter frequency regulation. Then, a small-signal model of the system including the generator, machine-side converter, and grid-side converter is developed for stability analysis. Finally, extensive simulation results and comparative discussions demonstrate that, compared with traditional and reference methods, the proposed method can avoid additional control algorithms, simplify parameter design, reduce grid-tied harmonics, and mitigate oscillations and overshoot significantly. The method can not only exhibit superior dynamic recovery performance and fault ride-through capability, but also adapt to various grid disturbance scenarios, and furthermore provide a feasible solution for improving grid stability under high renewable energy penetration.