Small Signal Stability Analysis of Dispatchable Virtual Oscillator Controlled Inverters with Adaptive Virtual Inertia Control

In this study, the small signal stability analysis of a system including adaptive modified dispatchable virtual oscillator control (dVOC)-based inverter connecting to a synchronous machine(SM) is conducted. Virtual oscillator-based controllers, such as dVOC are promising candidates for controlling the gridforming inverters as they provide faster dynamic response, more accurate synchronization and power sharing among different units. While the conventional dVOC is not able to provide inertial response, modified dVOC overcomes this deficiency. To leverage the advantages of modified dVOC in various cases, the adaptive modified dVOC is used, which its parameter design is critical. Additionally, the fast dynamic of this controller interacts the line as well as SM dynamics. To avoid these issues, in this study, a detailed stability analysis based on the eigenvalue analysis is conducted and the allowable boundary for controller coefficients are determined. Results highlight proper design of adaptive modified dVOC improves the system dynamic and eliminates the stability issues within the interaction of SM and inverter.