Limitations on the virtual inertia provision from grid-forming-connected renewable energy sources

This paper addresses the limitations of virtual inertia provision from grid-forming interconnected renewable energy sources considering AC grid and resources dynamics. The instantaneous power that the grid-forming can provide is limited by the DC link power availability, which depends on the resource dynamic power capacity and the energy stored in the DC link. Here, an analysis of the maximum virtual inertia a renewable source can provide is presented. From this analysis, a criterion to select the maximum virtual inertia able to be provided from the converter taking into account the time response of the renewable source, the DC link stored energy and the AC network inertia, is derived.