Low voltage ride through capability enhancement of PMSG-based wind turbine

This paper investigates the control and operation of permanent magnet synchronous generator (PMSG)-based wind generation systems employing the full-scale frequency converter under network fault conditions. The factors inducing the oscillations of DC-link voltage of the full-scale frequency converter during grid voltage dips are analyzed. A novel control strategy is proposed to suppresses the DC-link voltage oscillations and enhance the low voltage ride-through (LVRT) capability of PMSG-based wind turbine. The generator-side converter is controlled to maintain a stable DC-link voltage, while the grid-side converter is controlled to provide a dynamic coordinated control for the active and reactive power output according to the grid voltage amplitude variations during grid faults. The simulation results implemented in Matlab/Simulink show that the proposed control strategy not only improves the stability of PMSG by means of suppressing the DC-link voltage oscillation, but also provides a dynamic reactive power support to restraint the disturbance of the grid voltage. (5 pages)