OTM System Application Study (OTM-SAS).

Descriptions

The Carbon Trust is working on a major technology accelerator initiative focussed on reducing the cost of energy (GBP/MWh) from offshore wind by more than 10 %. The Offshore Wind Accelerator (OWA) is funding large-scale research, development and demonstration (RD&D) projects to unlock technological barriers to advance the industry, and thereby accelerate its development so that significant carbon emissions reductions are achieved. Projects have been selected based on their potential impact on the cost of offshore wind farms and on their ability to deliver operational improvements in the short to medium term. This initiative has been structured as a funding collaboration between the Carbon Trust and a number of international energy companies active in offshore wind farm development.A novel High-Voltage Alternating Current (HVAC) transmission solution was presented by ABB under the name of ‘Distributed AC Power Collection’ and by Siemens under the name of ‘Offshore Transformer Module (OTM)’. The 2 solutions strip an Offshore Substation Platform (OSP) down to its bare essentials and places the transmission assets (transformer and switchgear) on wind turbine generator substructures. Multiple modules can then be utilised to create the desired capacity for the grid connection of Offshore Wind Farms (OWF). Beatrice Offshore Windfarm Ltd. has adopted the OTM solution and will run a separate project (‘OTM Discretionary Project’) within the Offshore Wind Accelerator programme which will focus on the detailed development of the novel transmission solution. The specifications for the Beatrice OWF will serve as baseline for this study and will be further refined as the Front-End Engineering Design (FEED) for the Beatrice OWF progresses. It is expected that within the provided basis of design the Contractor will receive detailed analysis and findings from the Beatrice OWF project FEED study and this will be the starting point for a sensitivity analysis.The primary objectives of the project are to:— Investigate and evaluate opportunities for optimisation in conventional HVAC OSPs for OWF, other than the proposed OTM concepts, which reduce the number of components;— Investigate the feasibility of the OTM concept in OWF transmission projects in a variety of situations and configurations (standalone or part of another grid solution e.g. HVDC);— Compare market available OTM or ‘OTM like’ solutions with focus on their applicability to commercially available state-of-the-art offshore wind turbines;— Investigate the application of the OTM concept in HVDC grid connections and mid-point compensation HVAC 50 Hz.