Low voltage ride through(LVRT) research of DFIG

Nowadays Doubly Fed Induction Generator (DFIG) is used in variable speed wind power plants extensively. Doubly fed induction generator (DFIG) has many advantages such as low cost, reduced losses with an improved efficiency, variable speed operation and improved active and reactive power control capabilities. Since variable speed operation, output of total energy is much more,so capacity utilization is improved and cost of energy is reduced. But it is very sensitive to grid disturbance/fault for DFIG, especially the voltage dip. Since the doubly-fed induction generator (DFIG) has been widely used in wind energy conversion, the low voltage ride through (LVRT) technology of the DFIG has been investigated extensively in recent times. This paper focuses on the Asymmetrical fault ride-through capability of doubly fed induction generator (DFIG). The paper also provides an overview on the interaction between variable-speed DFIG and the power system subjected to disturbances. The dynamic behaviour of DFIG wind turbines during Asymmetrical grid faults is simulated and assessed.