Adaptive Frequency-Secure Unit Commitment with Wind-Based Virtual Inertia Support

The declining level of synchronous inertia in renewable-dominated power systems has made frequency security a critical issue in day-ahead scheduling. This paper develops an adaptive frequency-constrained unit commitment framework in which wind power plants provide time-varying virtual inertia according to the commitment-driven shortage of synchronous support. The proposed strategy activates wind-based frequency support only during periods in which the synchronous commitment pattern is insufficient to satisfy prescribed frequency-security requirements. A scheduling model is formulated by jointly coordinating thermal commitment, wind reserve, equivalent inertia, and aggregate frequency-security metrics. Comparative studies based on cold-climate load scenario show that the adaptive strategy avoids over-conservative support allocation and achieves a more effective balance between economic operation and frequency security.