Frequency Stability Assessment of Multiple Virtual Synchronous Generators for Interconnected Power Systems

Virtual inertia control is a promising concept to ensure frequency stability in power systems with high renewable power generation. Supply of virtual inertia is achieved by an inverter based virtual synchronous machine (VISMA), or virtual synchronous generator (VSG), emulating a synchronous generators behavior. The aim of this work is to study the behavior of multiple VISMA in a multi-area interconnected power system. A frequency control model of a three-area power system with virtual inertia control is presented. Based on this model, a scenario simulation study is conducted. The three-area model is compared to a one-area model of equal configuration. It is found, that the dynamic behavior of a multi-area power system can lead to stability issues. The instability causes are investigated. It is proposed that connection stability issues may be resolved by virtual inertia control integrating damping properties. Due to the promising results, potential is seen for further research on a detailed active and reactive power model.