Conductivity Modeling and Subsynchronous Oscillation Analysis of Multi-VSGs System

Considering the flexible integration of renewable energy, the multiple virtual synchronous generators (multi-VSGs) system provides favorable not only inertia but damping support to the new power network. Meanwhile, Sub-synchronous oscillation becomes more likely in a system with multi-VSGs. The research presents an approach to depicting the VSG’s active power and frequency control loops to a two-terminal conductance network, and the multi-VSGs’s dynamic response is analyzed. With the node matrices, it can be deduced that the sub-synchronous oscillation is influenced not only by the power references of the VSGs, but also by the interactions among different VSGs. The multi-VSGs’s comprehensive simulation model is developed with MATLAB software. The results of the simulation validate the accuracy and effectiveness of the theoretical analysis.