Replacement of Synchronous Generator by Virtual Synchronous Generator in the Conventional Power System

Virtual synchronous generator (VSG) has been proposed to mimic the synchronous generator in terms of voltage establishment and provision of virtual inertia from electric energy storage. It thus facilitates increased power electronics connected renewable penetration while maintaining the system stability. Besides virtual inertia, a well-functioning VSG also includes frequency droop control and voltage regulation, which corresponds to the turbine governor and automatic voltage regulation in the synchronous generator (SG). This leads to the question of whether such a VSG can fully replace the SG in the conventional power system and achieve 100% power electronics generation penetration. This paper tries to answer this question by first comparing SG and VSG and then replacing all of the SG by VSG in the IEEE 39-bus system under the assumption of the infinite electric energy storage capacity. The results verify that the VSG has the same function as SG and the system remains stable under 100% VSG penetration.