Impact of VSG on SSR of Turbine Generator

With the increasing penetration of renewable energy in power systems, researchers have proposed the virtual synchronous generator (VSG) control scheme to emulate the inertial characteristics of real synchronous machines (SM) to improve frequency stability because of the difference of grid-connected inverters from traditional synchronous generators. VSGs have an oscillation phenomenon similar to real SMs when disturbances occur, and will also interact with SMs due to power exchange as well as frequency and angle synchronization. In this case, how the existence of VSG affects the phenomenon of subsynchronous resonance (SSR) is an important issue. This article focuses on the impact of a VSG interconnected with a turbine generator with multi-mass shaft (MMS-TG). Results show that VSG will change the oscillatory modes of the TG and damp the oscillation under faults.