Analysis of the Impact of Control Modes of Grid-Forming Inverters in 100% Renewable Energy System on System's Small-Signal Stability

Future 100% Renewable energy power systems will be complex, with many grid-following and grid-forming power electronic devices. When the grid is disturbed, grid-forming inverters support system frequency and voltage. Different grid-forming control strategies impact small-signal stability, so selection criteria for control methods under different operating conditions are needed. This paper models a 100% renewable energy power system with both grid-following and grid-forming devices through mathematical modeling. Using small-signal analysis, it evaluates the impacts of droop control and virtual synchronous control of grid-forming inverters on system stability.