The virtual synchronous generator (VSG) is an effective way to improve the stability of a new power system based on new energy. The VSG applied to inverter-interfaced renewable generation (IIRG) may lose VSG characteristics under unbalanced voltage drops, and may cause generator tripping because of insufficient low-voltage ride-through capability or voltage and current over-limit. This endangers the safe and stable operation of the power system. A new VSG control strategy is proposed in this paper. This method can not only provide system inertia and damping, but also provide active voltage support when there is unbalanced voltage drop, effectively improve the low voltage ride-through capability of VSG, and ensure system stability under disturbance. First, the response characteristics of a traditional VSG with an unbalanced voltage drop are analyzed. Then, an improved control structure based on balanced current is proposed, one which changes the traditional single current loop control of VSG to double current loop control, maintains the inertial damping characteristics of VSG under voltage drop conditions, and realizes the accurate control of positive and negative sequence components. Then, based on the improved control topology, in a safe operational condition of the inverter, the positive and negative sequence reference current setting is optimized to realize VSG active voltage support and current limiting. Finally, based on the Matlab/Simulink simulation platform, the response characteristics of the proposed control strategy in various system operating conditions are verified. This ensures the effectiveness of the method. This work is supported by the National Natural Science Foundation of China (No. 61873159).