Virtual synchronous control for doubly-fed induction generator(DFIG)is a promising control technique to provide frequency and voltage support when DFIG is integrated to power grid. Existing virtual synchronous control strategy for DFIG mainly focuses on mimicking the electromechanical dynamic behavior of synchronous generator

while paying little attention to the control strategy during electromagnetic transient process. This paper firstly analyzes the fault characteristics of virtual synchronous control based DFIG during asymmetrical grid faults

and reveals the major flaws of existing virtual synchronous control strategy

that is

incapability of limiting the fault current and oscillations of electromagnetic torque of DFIG. Then

a voltage compensation virtual synchronous control strategy for DFIG is proposed. The main principle is compensating the fault components of the control voltage of rotor side converter to weaken the influence of the fault components of electromotive force in rotor windings

and therefore suppressing the overcurrent in DFIG rotor. Finally

simulation analysis is given to compare the performances of existing and proposed virtual synchronous control strategies

which validates that the proposed virtual synchronous control strategy can not only maintain the advantage of providing inertial support

but also effectively limit the overcurrent in DFIG rotor and the oscillations of electromagnetic torque. Therefore

the possibility for DFIG can be improved to implement fault ride-through during asymmetrical grid faults.