Analys av risk för utmattningsskader på högspänningskablar vid fogning till havs
Typ
Examensarbete på grundnivå
Program
Maskinteknik 180 hp (högskoleingenjör)
Publicerad
2023
Författare
El-Zein, Alexander Hani
Parviz, Erfan
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Global conditions have forced humanity to look for new methods to generate renewable
energy. At the forefront of this innovation is NKT HV Cables AB in Karlskrona with the
promising as well as effective method to generate electricity through wind turbines in areas
named Offshore wind turbine parks. Large quantities of electricity are produced through wind
turbines that are located at sea which need transportation to land via high voltage cables. To
maximize this energy production, more and more wind turbines are located further out at sea
which means that high voltage cables need to be jointed on a vessel at sea.
The jointing operation can take several days, during this process, the cable is hanging from
the vessel which can cause damage. Waves and movement of the vessel can cause bending
motions along the cable which can be problematic for a longer period. It is necessary to
ensure that no critical damage is induced on these high voltage cables as it can cost the
company not only precious time but also a lot of money.
NKT has developed a new sensor that can monitor bending variations during a jointing
operation.
The goal of this thesis is to develop the process and provide graphs used by data from the
sensor, that can be analyzed and finally discuss the possible damage. MATLAB is used in
order to produce the plots and graphs.
25 plots are presented at the result chapter which show the curvature variations in x and y
axis and how the cable bends for one hour surveillance. Rainflow diagram is also presented in
this chapter which indicates the number of cycles and corresponding curvature variation.
The result and the effect of these cycles and variations is discussed in the last chapter. The
accuracy of the result and method is discussed as well. Further, a conclusion and judgement
to determine if the result is useful and valid, and whether NKT has been able to achieve their
objectives with the project and if the cable has been damaged to a dangerous level.