Stability and Sensitivity Analysis of Multi-Vendor, Multi-Terminal HVDC Systems

Multi-terminal HVDC projects are increasingly developed in recent years to enhance the flexibility of energy transmission. Differing from point-to-point systems, it is more challenging design multi-terminal system and ensure stable interoperability among converter especially when converters manufactured different vendors. Although impedance-based stability analysis allows for analyzing such systems based on black-box models, still difficult utilize those models identify root cause potential instability. To tackle this challenge, paper proposes a multi-level sensitivity approach using frequency-domain functions criterion. The proposed method differs classical state-space or transfer-function as purely impedance models. Case studies four-terminal carried out measurement PSCAD, through which most sensitive station can be identified. theory analyzed results finally validated by electromagnetic transient simulations.