A robust STATCOM control to augment LVRT capability of fixed speed wind turbines

In this paper, we propose an algorithm to design a robust output feedback controller for a static synchronous compensator (STATCOM) to enhance the low-voltage ride-through (LVRT) capability of fixed-speed wind turbines equipped with induction generators. The wind generator is a highly nonlinear system, and in this paper it is modelled as a linear part plus a nonlinear part. The nonlinear part is written as the Cauchy remainder term in Taylor series expansion; this enables us to use the bound of this term in robust control design. Large disturbance simulations demonstrate that the proposed controller enhances voltage stability as well as transient stability of induction generators during low voltage ride through transients and thus enhances the LVRT capability.