Lifetime estimation and performance evaluation for offshore wind farms transmission cables

Abstract

A novel methodology for life estimation and performance evaluation of offshore wind farms high voltage AC export cables is presented. The method applies Dynamic Temperature Prediction (DTP) analysis using a Thermo-Electrical Equivalent model (TEE). Furthermore, it is suggested how the cable lifetime might be inferred based on the accumulated ageing effects. Afterwards, a sensitivity analysis of the seabed temperature variations is performed. Finally, a holistic procedure for calculating more accurately the electrical power losses of the cable is presented. Results show that an important increase of the total installed power, or cross-section reduction, can be achieved compared to traditional sizing methods.

Economic performance of an overplanted offshore wind farm under several commitment strategies and dynamic thermal ratings of submarine export cable

“…However, in this paper, at the first stage, we restrict our study to the subsea section excluding both the landfall section and the junctions. It may be noted that, in HVAC export cables, the conductor temperature usually represents the limiting factor for the transfer capacity rather than other constraints such as voltage swing or surge impedance [77].…”

Optimum sizing of offshore wind farm export cables

“…1) Simulation Setting: Defines the main simulation parameters: i) seabed multilayer definition N (as introduced in [20]), ii) cables lifetime design information: LT des , d des , and F p des , iii) cables catalogue, and iv) geometrical and thermal information of the cables inner layers.…”

“…A Thermo-Electrical Equivalent (TEE) model based on the works [21] and [22] have been developed and calibrated as presented in [20]. The theoretical and practical validation of this model can be found in [16] and [10].…”

“…Temperature varies in time resulting in variation of the conductor and other associated losses (screen, armouring, and dielectric). Consequently, the total losses (T L it ) calculation for a cable t is defined in ( 18) [20].…”

“…The factor (1 + λ 1 + λ 2 ) accounts for the screen and armouring losses, while the constant 3 is for the three-phase system. It is observed that l D T should be between 10 − 20 (depending on cable total length) to achieve a proper computation time-quality balance [20].…”