École Nationale Supérieure de
Techniques Avancées

Abstract

Connecting offshore wind farms requires a detailed understanding of the thermal and electrical mechanisms in high-voltage cables, mainly HVAC, used to transport energy. This work proposes a detailed model of the thermal behavior of power cables, incorporating the internal structure of the cable, the different types of losses (Joule effect, dielectric losses, skin and proximity effects, induced currents) and interactions with their environment (soil, water; conduction, convection). An electrical analogy is used to construct an equivalent thermal diagram, enabling dynamic temperature calculation using a matrix method adapted to cylindrical and three-phase geometries. Soil modeling is optimized via exponential discretization of layers, based on local geotechnical properties. Applying the model to real DTS (Distributed Temperature Sensing) data enables the development of robust indicators for detecting cable unearthing, comparing simulated and measured temperatures across the entire link. Several detection methods (fixed thresholds and statistical approach) are compared. Finally, a sensitivity analysis of the main electrical, thermal, and geometric parameters is performed.