Review on Control Strategies of VC-DFIG.

With the increasing proportion of wind turbines, the characteristics of low inertia and weak damping of power grid become more obvious, which brings new challenges to the smooth operation of power grid. Traditional current-controlled strategy is difficult to obtain accurate grid synchronization information in weak power grid by using phase-locked loop. Based on voltage-controlled, power balance equation is constructed to obtain synchronization angle, which has good operation performance in weak power grid. For this reason, firstly, the outer loop synchronous mode and the inner loop control structure were classified to study the voltage-controlled structural deformation. Then, for the weak power grid scenario, the impedance/admittance modeling was combined to analyze the stability of the voltage-controlled weak power grid. And the strategy of suppressing medium-high frequency oscillation in the complex power grid scenario was proposed. At the same time, the field operation test of high-power voltage-controlled doubly-fed induction generations (DFIG) was introduced. Finally, the development direction of voltage-controlled was pointed out to provide reference for the follow-up research. [ABSTRACT FROM AUTHOR]