Validation of a Simplified Thermal Model for 525 kV HVDC Cables via Finite Element Analysis

Inhalt:
The transition to renewable energy sources intensifies the need for efficient and flexible power system operations. Thermal reserves of high-voltage direct current (HVDC) cables can expand the provision of curative system management measures as a new degree of freedom. This study presents the validation of a simplified analytical thermal model for a 525 kV HVDC underground cable, by comparing it to a detailed numerical model employing the Finite Elements Method (FEM) is implemented. The FEM model accounts for radial heat transfer and incorporates realistic cable geometry, material parameters, and boundary conditions derived from international standards. Comparative simulations support secure operational planning by revealing that the analytical model provides conservative temperature estimates, especially within typical soil thermal resistance ranges. Deviations at extreme conditions suggest correction factors for enhanced precision. The findings confirm the analytical model’s robustness and justify its integration into real-time system operations. The study emphasises the potential of utilising thermal reserves in HVDC infrastructure, contributing to grid optimisation and reduced Redispatch costs. Future research will address dynamic soil properties and optimised trench environments to refine thermal modelling.