Hierarchical Hybrid Non-Delay Decoupling Parallel Method for Electromagnetic Transient Simulation of DC-Collector Offshore Wind Farms

• • For a 96-turbine DC-collector offshore wind farm, the proposed hierarchical hybrid decoupling achieves an 11.99x speedup over the detailed model (simulation time reduced from 2.04×10^5 s to 1.7×10^4 s), whereas series-only and parallel-only decoupling yield only 8.77x and 6.22x speedups, respectively. This 36.7% improvement over series-only decoupling directly translates to reduced computational cost for real-time hardware-in-the-loop testing. • • The method maintains high accuracy: MAE for a-phase voltage Va is 0.1011 p.u., and RMSE is 0.6318 p.u.; for output active power Pout, MAE is 0.0616 p.u. and RMSE is 0.0877 p.u. These errors are within acceptable bounds for control and protection system validation, ensuring that decoupling does not compromise simulation fidelity. • • Scalability is demonstrated across wind farm sizes: speedup increases monotonically with turbine count—2.76x for 4 turbines, 4.65x for 12, 8.96x for 40, and 11.99x for 96—indicating that the hierarchical hybrid method becomes increasingly advantageous for large-scale farms, where detailed simulation becomes computationally prohibitive (2.04×10^5 s for 96 turbines). • • The hybrid method outperforms single-strategy decoupling: at 96 turbines, it achieves 11.99x speedup versus 8.77x (series-only) and 6.22x (parallel-only), a 36.7% and 92.8% relative improvement, respectively. This validates the layered integration of MATE and its dual as a superior approach for complex series-parallel topologies, reducing matrix size and enabling synchronous partition solving.