Improved active power control of virtual synchronous generator for enhancing transient stability

Virtual synchronous generators (VSGs) are widely used as grid-forming control converters in the inverter-dominated power system. Similar to synchronous generators (SGs), there would also be transient instability of VSGs under certain conditions. In this paper, the transient dynamics of VSGs during gird faults are fully investigated based on the large-signal model. It is revealed that the significant deteriorative of active power control loop (APCL) is the main factor on the transient stability of VSGs. Thus, for enhancing transient stability during grid faults, an integrator-based feedback loop is introduced for APCL. Then, an enhanced active power control of VSGs is presented with transient stability enhancement during grid faults. Moreover, the impacts of different integral parameters on the transient stability of VSGs are studied. Finally, the validity of the transient stability enhancement of VSGs is demonstrated by the hardware-in-loop (HIL) results.