Offshore Wind Power System Resonance Stability: Modelling, Analysis, and Methods Comparison

The resonance risks are high in offshore wind power systems (OWPSs) due to the capacitive effect of submarine cables and the negative resistance effect (NRE) of wind turbines. The s-domain node admittance matrix (s-NAM) method is suitable for OWPS resonance stability analysis, but its relationship with the widely used Nyquist and NRE methods in the frequency domain is unclear. To analyze resonance stability accurately, this paper builds impedance models for common OWPS components and compares three analysis methods. The case study of a practical OWPS shows that the three methods are consistent in qualitatively assessing resonance stability; they differ in quantitatively identifying resonance frequency but are close in low-damping modes and identical in the undamped system.