Influence of Virtual Inertia and Virtual Damping Distribution on Frequency Stability and Small-Signal Stability

In the gradual transition from traditional thermal power units to variable renewable generation (VRG), the reduced inertia associated with VRG can pose challenges to frequency stability. To deal with this matter, the implementation of virtual inertia control is introduced, instilling analogous inertial characteristics in VRG and bolstering frequency support. However, this method introduces uncertainties in mitigating small-signal stability issues, potentially impacting the system’s resilience to small disturbances. This study investigates the impact of virtual inertia along with virtual damping allocation on the frequency stability coupled with small-signal stability of a multi-machine power system dominated by renewable energy sources. The manuscript proposes a model and methodology for optimizing the allocation of virtual inertia as well as virtual damping to augment small-signal stability. Initially, models for frequency response and small-signal stability are formulated. Subsequently, a particle swarm algorithm is applied to tailor the virtual inertia as well as virtual damping parameters for each VRG unit. Ultimately, the proposed optimization approach’s effectiveness and reliability are confirmed via time-domain simulations.