This paper presents a novel approach to incorporate a grid forming capability into a grid-following voltage source converter, while maintaining the high-bandwidth current control capability that is typical of such a converter. The approach uses the resonator outputs of a stationary frame current regulator as a virtual flux estimation of the converter output voltage, and integrates this estimation into an electrical model of a virtual synchronous generator without requiring integration and derivative operations. The generator and converter models are then combined to achieve a robust grid-forming response under grid islanding conditions, without requiring direct grid-side voltage measurements. The proposed strategy is validated using a detailed switching simulation model of the converter and its control processes.
