Coordinated control for low voltage ride through in PMSG wind turbines

This work proposes a control strategy for permanent magnet synchronous generator (PMSG) based wind energy conversion systems (WECSs) to improve low voltage ride through (LVRT) capabilities. The nonlinear relationship between the generator speed and DC-link voltage is considered by using feedback linearisation. To support the grid during LVRT, the DC-link voltage is controlled by the machine side converter (MSC). The kinetic energy stored in the wind turbine inertia is used to compensate for lower voltage. Further, pitch angle control is used to ensure stable operation, and to guarantee the rotor speed does not exceed the rated value. A simulation of a 2MW PMSG wind turbine is conducted to validate the proposed control strategy.