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The focus of this study was to analyze offshore wind power’s future options and maximum value creation for Åland, covering the most feasible solutions for exporting of green electricity, feasibility of hydrogen production and transmission, alternative strategies, and steps for developing offshore wind-based business in Åland, as well as assessment of risk and opportunities and propose next steps for Åland with offshore wind. Beside this study, a review of existing offshore wind power was made as a master’s thesis. The large wind farm areas F4 and F6 in the northern side of Åland with capacity of about 4 GW and annual generation of 20 TWh turned out to be the most feasible when considering transmission of electricity. Åland wind farms locate in the area, where the farm connection could provide possible basis for interconnection of two power systems, too. The additional cost for a solution where energy transmission from wind farm could be done to both Finland and Sweden is approximately +5 €/MWh compared to the solution where wind capacity is realized only to one direction. The green hydrogen potential for the region is about 18 TWh (12 TWh North, 6 TWh South). For reference, Finland’s annual natural gas consumption is about 24 TWh. Hydrogen production at sea and pipeline transmission to continental Finland is estimated to be about 20% cheaper compared with alternative case based on electricity transmission to continent and conversion to hydrogen onshore. Comparing the electricity and hydrogen as products, electricity creates less interdependencies because the available grid offers access to electricity market. However, in the beginning, transmission of hydrogen is tied to one-to-one connections, which makes parties dependent on each other’s. Identification of potential hydrogen customers and applications is necessary for successful implementation. The proposed road map is to finish preliminary studies and go into development of wind farm in the area F6. During the development of the wind farm, uncertainties related to market for electricity, hydrogen and P2X products, as well as regulation for hydrogen and P2X, will decrease. Publishers version

A method is presented for tooltip tracking in active magnetic bearing (AMB) spindle applications. The proposed tool tracking approach uses control of the AMB air gap to achieve the desired tool position. A μ-synthesis-based controller is designed for the AMBs with the goal of robustly minimizing the difference between the tool reference and estimated tool position. In such a way, the model-based control approach concurrently addresses the tracking problem and the inability to directly measure real-time tool position in the presence of machining disturbances. To ensure the tractability of the control problem, a model of the desired tracking dynamics is included in the plant. The method is demonstrated on a high-speed AMB boring spindle. To confirm the tool tracking capability, characteristic part geometries are traced including stepped, tapered, and convex profiles. Tool tracking is demonstrated for the rotating AMB spindle in the range of 90 μm. Also, static and dynamic external loading is applied to the spindle tool location to confirm the disturbance rejection ability of the closed-loop system.

This paper presents the practical results of the design analysis, commissioning, identification, sensor calibration, and tuning of an active magnetic bearing (AMB) control system for a laboratory gas blower. The presented step-by-step procedures, including modeling and disturbance analysis for different design choices, are necessary to reach the full potential of the prototype in research and industrial applications. The key results include estimation of radial anda xial disturbance forces caused by the permanent magnet (PM) rotor and a discussion on differences between the unbalance forces resulting from the PM motor and the induction motor in the AMB rotor system.

In this paper, the state-of-the-art AMB controller structure, with an outer centralize dposition control loop with reference currents and inner current control loops, is replaced with an outer control loop with force references and inner flux control loops. The linearization of the for ceactuators and different control schemes of the centralized outer control for the radial suspension are considered. The operation of the proposed control under a zero bias is verified by simulations. The proposed control solution can achieve a dynamic performance comparable with that of a controller with the classical bias current.