Resonance Stability Analysis for Offshore Wind Power Systems Based on s ‐Domain Node Admittance Matrix Method and Impedance Aggregation

ABSTRACT

Offshore wind power is developing rapidly. The high resonance stability risks in offshore wind power systems (OWPSs) caused by submarine cables’ capacitive effect and wind turbines’ negative resistance effect have drawn much attention. The s‐domain node admittance matrix (s‐NAM) method is suitable for analysing resonance stability in OWPSs, while its efficiency is limited by massive high‐order determinant calculations. To improve efficiency, this paper combines impedance aggregation with the s‐NAM method. First, the resonance modes and mode shapes in the impedance aggregated system are analysed, and their partial inheritabilities are discovered. Then, regional observability and linkage are defined to distinguish between global and local resonance modes. Furthermore, a resonance stability analysis strategy for OWPSs based on the s‐NAM method and impedance aggregation is proposed. With this method, the resonance stability analysis for the original complex system can be divided into the ones for several small subsystems with aggregated impedances. Finally, the case studies of a practical OWPS are conducted, whose analytical calculations and simulation verification demonstrate the feasibility of the proposed strategy.