Induced Losses in Non-Magnetically Armoured HVAC Windfarm Export Cables

Presently, IEC 60287-1-1 is used to calculate the ratio of induced loss in a cable’s metal sheath to its conductor loss λ 1 , considering uniform current density in both conductors and sheaths. Although this assumption is reasonable for smaller cables, it becomes questionable for larger cables in close proximity, such as three-core (3C) export cables in Offshore Wind Farm (OWF) projects. The present study employs 2-D Finite Element (FE) models to evaluate how accurate the Standard method for calculating the λ 1 factor is in cables with non-magnetic armour. Their validity is further enhanced by measurements in a 3x1000 mm ² 155 kV unarmoured cable. IEC 60287 appears to overestimate the temperature, particularly for larger conductor sizes, by up to 7°C. Finally, suitable Reductive Factors (RFs) are derived which could improve the accuracy of the IEC method.