Analysis and mitigation of participation factors weak robustness in direct-drive wind farms connected to VSC-HVDC system

The participation factors of close sub-synchronous oscillation modes in direct-drive wind farms connected to VSC-HVDC system are greatly affected by parameter perturbations. This affects the damping controller optimal configuration. In light of the issue, participation factors weak robustness is revealed with the matrix perturbation method, and its negative impact on damping controllers is explained. Then, the participation factors weak robustness phenomenon and its hazards are analyzed. Finally, a mitigation method of participation factors weak robustness is proposed. PSCAD/EMTDC simulations are conducted to verify the analysis results.