Stability and interaction analysis of grid-forming Type IV wind turbines

The global shift to renewable energy, especially wind power, is critical for achieving carbon-neutral power systems but poses challenges to grid stability due to reduced system inertia from inverter-based resources. Grid-forming (GFM) control modes are emerging as key solutions to these stability issues. Given the vast potential of wind energy, ensuring that wind turbine generators (WTGs) comply with GFM control standards is essential. This paper explores GFM capabilities in Type IV WTGs, focusing on the interactions between grid-side and machine-side control dynamics. A simplified small-signal model is developed to efficiently analyse the direct coupling between active power and DC-link control, highlighting how GFM parameters like droop and inertia, along with the DC controller bandwidth, affect system stability. Time-domain simulations validate the proposed tuning guidelines and reveal distinct WTG response characteristics at different wind speeds during grid contingencies. These insights lay the groundwork for robust GFM control designs, essential for a stable integration of wind turbines into high-renewable power systems.