The centralized construction of renewable energy bases in desert areas and the long-distance transmission of electricity to the load centers represent a key strategy for developing and utilizing renewable energy in China. The dynamic interaction and coupling between the devices within the renewable energy bases can easily result in broadband oscillation problems

posing challenges to the safe and stable operation of the system. Existing research mainly focuses on the analysis of oscillation mechanisms and suppression methods at the level of a single machine or a station

with less attention given to oscillation risk assessment at the level of renewable energy bases. This paper proposes a multi-port screening method to predict and evaluate potential oscillation risks at the renewable energy base level. First

a broadband impedance sub-band fitting method is introduced based on the vector fitting algorithm

and a frequency domain network model and a dual-input and dual-output feedback system are established for the system. Next

a system stability evaluation method and indicators considering the right half-plane poles of the open-loop transfer function are proposed

and a screening method for the oscillation risk of the multi-station considering the system's operation modes is proposed. Finally

an electromagnetic transient model of a typical renewable energy base is established

and the effectiveness of the proposed method is validated through case studies.