Ageing and Lifetime of Medium Voltage ROV Umbilical Cables
S. shah (TU Delft - Electrical Engineering, Mathematics and Computer Science)
M. Ghaffarian Niasar – Mentor (TU Delft - High Voltage Technology Group)
P. Vaessen – Graduation committee member (TU Delft - High Voltage Technology Group)
A. Shekhar – Graduation committee member (TU Delft - DC systems, Energy conversion & Storage)
Evert van Veldhuizen – Mentor (DeRegt Cables)
Auguste Sans – Mentor (DeRegt Cables)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Remotely operated vehicles (ROV) are used for the inspection, maintenance and repair of submarine and offshore cables, subsea exploration, and rescue operations. ROVs are powered by umbilical cables, which have to withstand electrical, mechanical, and thermal stresses. This thesis investigates the effect of repetitive bending on the insulation properties of ROV umbilical cables for medium voltage.
Umbilical cables with XLPE, polypropylene, and HDPE insulation were mechanically aged using a cyclic bend-over-sheave setup, after which the dielectric properties were analysed using electrical breakdown tests and several diagnostic tests, such as partial discharge analysis.
The cables with XLPE and HDPE insulation showed delamination of the conductor–insulation interface, which resulted in increased partial discharge activity, a reduced breakdown voltage, and a significantly decreased lifetime. For HDPE, the lifetime power law exponent 𝑛 dropped from 18 to 9 after 23,000 cycles of mechanical ageing. Polypropylene, on the other hand, did not show delamination but an increase in dielectric-bounded cavities with mechanical ageing.