FR

F. Raimondi

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An effective magnetic control strategy for monopile during post-upending lowering under wave loads

In response to the transition toward sustainable energy production, offshore wind farms are increasingly being developed in deeper and more challenging marine environments. This shift necessitates larger and heavier turbine structures. To address these challenges, innovative installation approaches are being explored that aim to enhance efficiency, improve positioning accuracy, and maintain high safety standards.

This thesis explores the development and application of magnetic, non-contact control strategies for monopile installation during offshore wind turbine deployment. In particular, the research focuses on designing an effective control method that utilizes dipoles magnetic forces to regulate the motion of a partially submerged monopile during its lowering phase.

To achieve this, a dynamic model of the crane-monopile system was developed based on a double pendulum configuration. This model incorporated both wave-induced loads and the progressive submersion of the monopile, with hydrodynamic forces calculated using Airy wave theory and Morison’s equation. This setup enabled a realistic assessment of how magnetic interaction behaves under typical and realistic environmental and operational conditions.

The system’s dynamic behavior was investigated both analytically, where feasible, via eigenvalue analysis, and numerically through time-domain simulations. These analyses considered the combined effects of wave loading and submersion depth on the response of the system. A proportional-derivative (PD) controller was implemented to govern dipole-dipole magnetic interactions, enabling active control of the monopile’s motion. The model also accounted for nonlinearities present in magnetic forces and hydrodynamic drag.

Through this control framework, the magnetic moment required to maintain system stability was quantified. However, it became evident that force magnitude alone does not fully determine control effectiveness. Therefore, different design parameters, particularly the horizontal spacing between magnets, their vertical positioning along the monopile and the dipole moments, were systematically evaluated to identify configurations that optimize control performance.

Compared to conventional installation methods, the proposed non-contact magnetic control strategy offers several distinct advantages. It does not depend on mechanical attachment to the monopile or active human intervention, which reduces potential damage and improves operational safety. Furthermore, it enables more precise and distributed control, as magnetic actuators can be placed at multiple locations along the monopile, enhancing the system’s ability to counteract dynamic responses.

Overall, this research contributes to the broader understanding of magnetically controlled systems and supports the development of more advanced methods for offshore wind turbine foundation installation. ...
This design report outlines a preliminary masterplan for developing a sustainable village in Patagonia, Argentina, addressing the unique challenges of remote living within a sensitive natural landscape. The project centres on creating a resilient, socially sustainable community that coexists harmoniously with its environment. A key objective is to assess multiple sustainable options for essential infrastructure, encompassing energy supply, accessibility, water and wastewater management, and other critical systems.
The report begins with an exploration of the site’s distinctive environmental conditions, informed by a two-week site visit, as well as an analysis of key stakeholders, including residents, tourists, and potential investors. This groundwork establishes both community needs and environmental constraints, forming the guiding principles for the design. The preliminary masterplan then proposes practical solutions to meet these requirements, including infrastructure development such as jetties for enhanced accessibility, a hybrid renewable energy system to support off-grid living, and water and waste management systems that minimise ecological impact.
The proposed design is evaluated for economic feasibility, ensuring the village can support sustainable eco-tourism and community growth over the long term. This project could be used as an example for future developments in rural areas by prioritising sustainability for all social, environmental and economic aspects. This preliminary masterplan aims to contribute to ongoing research on environmentally conscious and socially inclusive development in challenging environments. ...