Browsing by Keyword "Wind energy"
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Item Analysis of loss of life of dry-type WTSU transformers in offshore wind farms(2020) Etxegarai, A.; Valverde, V.; Eguia, P.; Perea, E.; DIGITAL ENERGYCurrently, dry-type transformers are commonly installed as wind turbine step-up (WTSU) transformers, especially in offshore wind farms. Due to their low flammability and resistance to moisture, their performance is optimal in offshore platforms. Nonetheless, their thermal-electrical degradation must be carefully considered given the special wind and weather conditions in marine environments. The present paper studies the thermal aging of dry-type WTSU transformers in offshore wind farms considering the most thermally stressed location i.e. the winding hot-spot. The estimation of the transformer lifetime consumption introduced in this work can be applied in the framework of digital twins for diagnostic and prognostic monitoring purposes The thermal degradation study is based on a typical offshore load profile and includes the analysis of the impact of several transformer characteristics and operating conditions. As a result of the analysis, it can be concluded that lower temperature insulations, forced air cooling systems, a lower mean winding temperature rise and cool ambient temperatures lead to decreased loss of life values. Also, the present work suggests the suitability of considering thermal degradation studies as an optimal sizing factor for offshore WTSU given the low ambient temperatures in marine environment and the low capacity factors.Item NAUTILUS-DTU10 MW Floating Offshore Wind Turbine at Gulf of Maine: Public numerical models of an actively ballasted semisubmersible: Public numerical models of an actively ballasted semisubmersible(2018-10-10) Galván, J; Sánchez-Lara, M J; Mendikoa, I; Pérez-Morán, G; Nava, V; Rodríguez-Arias, R; RENOVABLES OFFSHORE; Tecnalia Research & InnovationThis study presents two numerical multiphysics models of the NAUTILUS-10 floating support structure mounting the DTU10 MW Reference Wind Turbine at Gulf of Maine site, and analyses its dynamics. With the site conditions and the FAST model of the onshore turbine as the starting point, the floating support structure: tower, floating substructure with its corresponding active ballast system and station keeping system, was designed by NAUTILUS. The numerical models were developed and the onshore DTU wind energy controller was tuned to avoid the resonance of the operating FOWT by TECNALIA, in the framework of H2020 LIFES50+ project. This concept and its subsystems are fully characterised throughout this paper and implemented in opensource code, FAST v8.16. Here, the mooring dynamics are solved using MoorDyn, and the hydrodynamic properties are computed using HydroDyn. Viscous effects, not captured by radiation-diffraction theory, are modelled using two different approaches: (1) through linear and quadratic additional hydrodynamic damping matrices and (2) by means of Morison elements. A set of simulations (such as, decay, wind only and broadband irregular waves tests) were carried out with system identification purposes and to analyse the differences between the two models presented. Then, a set of simulations in stochastic wind and waves were carried out to characterise the global response of the FOWT.Item Risk Assessment of a Wind Turbine: A New FMECA-Based Tool With RPN Threshold Estimation: A New FMECA-Based tool with RPN threshold estimation(2020) Catelani, Marcantonio; Ciani, Lorenzo; Galar, Diego; Patrizi, Gabriele; Tecnalia Research & InnovationA wind turbine is a complex system used to convert the kinetic energy of the wind into electrical energy. During the turbine design phase, a risk assessment is mandatory to reduce the machine downtime and the Operation & Maintenance cost and to ensure service continuity. This paper proposes a procedure based on Failure Modes, Effects, and Criticality Analysis to take into account every possible criticality that could lead to a turbine shutdown. Currently, a standard procedure to be applied for evaluation of the risk priority number threshold is still not available. Trying to fill this need, this paper proposes a new approach for the Risk Priority Number (RPN) prioritization based on a statistical analysis and compares the proposed method with the only three quantitative prioritization techniques found in literature. The proposed procedure was applied to the electrical and electronic components included in a Spanish 2 MW on-shore wind turbine.Item Study of Useful Life of Dry-Type WTSU Transformers(2020-06) Etxegarai, A.; Valverde, V.; Eguia, P.; Perea, E.; DIGITAL ENERGYDry-type transformers are rapidly becoming popular as wind turbine step-up (WTSU) transformers, especially in offshore wind farms. Cast resin transformers are not flammable and are also resistant to moisture. However, their thermalelectrical degradation must be carefully analysed given the special conditions of wind farm installations. The present paper studies the remaining useful life (RUL) calculation of dry-type WTSU transformers based on the most thermally stressed location i.e. the winding hot-spot. The estimation of the loss of life of the transformer can be used for diagnostic and prognostic monitoring purposes in the framework of digital twins. The methodology is then applied to a typical WTSU load profile and the impact of several transformer characteristics and operating conditions are compared to the reference case.