Cable Model Order Reduction for HVDC Systems Interoperability Analysis

In order to predict the stability of cable-based offshore Voltage Source Converter High Voltage Direct Current (VSC HVDC) systems, an accurate cable model is needed to represent the characteristics of the transmission system. This paper presents a model consisting of cascaded pi-sections with multiple longitudinal parallel branches, allowing for a detailed representation in the frequency domain. Furthermore, a cable model order reduction for system interoperability studies is proposed based on the identification of interacting modes. Simulation results demonstrate how a classical cascaded pi-model is unable to accurately represent the interacting modes and show how the state-space representation of the proposed cable model can be reduced whilst preserving an accurate representation of the converter interactions.