Objective To address the risks of low inertia, weak damping, and transient instability caused by the grid connection of high-proportion distributed photovoltaic (PV)-wind power clusters, this study investigates multi-time scale coordinated inertia support and transient stability optimization control.

Method A coupling model integrating the microsecond-level response of PV inverters and the millisecond-level virtual inertia of wind turbines was established to overcome the limitations of single-source inertia modeling and achieve multi-source time-scale matching. Furthermore, a three-level control architecture comprising "transient emergency inertia support, dynamic coordinated damping regulation, steady-state optimal dispatch" was constructed, covering full-cycle operation scenarios from fault ride-through to long-term stability.

Result Based on real-time operation data, a multi-objective optimization strategy is designed with the objectives of minimizing inertia support costs and maximizing transient stability, thereby enhancing the adaptive capability of the control system. Case analysis demonstrates that the proposed model can limit the multi-source inertia coordinated response error to within 5%, increase the transient stability margin by over 20%, and shorten the dynamic adjustment time by 30%.

Conclusion This study provides a complete technical pathway of 'analysis-control-optimization' for the grid integration of high-penetration distributed new energy, which holds significant engineering value for enhancing the system's transient stability and multi-time scale operational performance.