Power System Stability Improvements Through Grid Forming Inverters for Systems with High Penetration of Grid Following Inverters

The power transmission system is rapidly changing due to the integration of renewable sources such as wind and solar power. However, these additions are converter-based hence their behavior is different from traditional synchronous generator-based power systems. In addition, the majority of the converters are grid-following inverters and a high share of grid-following inverters can have adverse effects on the power system stability. To mitigate the adverse effects, a new concept called grid-forming inverters is emerging. This paper studies the ability of the grid-forming inverters to maintain the power system stability under high inverter-based resource scenarios up until 100% inverter-based resource share. The research identified that the two-area Kundur model is stable up to 50% grid following inverter share and with the use of a sufficient share of grid-forming inverters, the system can reach up to 100% inverter-based resource share. Furthermore, the location sensitivity of the grid-forming inverter and the effects of different power flow scenarios at high inverter-based resource share were studied.