FAULT RIDE-THROUGH CAPABILITY AND DAMPING IMPROVEMENT IN DFIG

Doubly-fed induction generator wind turbine is susceptible to faults and requires crowbar protection. When the crowbar is triggered, the rotor is short circuited over the crowbar impedance. Then, the doubly-fed induction generator operates as a squirrel-cage induction generator that tends to absorb large amount of reactive power from the grid during fault, potentially causing a voltage drop. This paper, therefore, proposes the use of doubly-fed induction generator based lowvoltage-ride-through scheme including crowbar, rotor-side converter, grid-side converter and power system stabilizers. In this way, the transient stability and damping of the electro-mechanical oscillations of a grid-connected doubly-fed induction generator is obtained. The simulation results highlight that the proposed control scheme improves the operation of doubly-fed induction generator during faults. The investigation is realized by comparing the performance of doubly-fed induction generator system with and without the low-voltage-ride-through and damping control scheme