A Rare-Earth Free Magnetically Geared Generator for Direct-Drive Wind Turbines

Zeinali, Reza
Keysan, Ozan
A novel Vernier type magnetically geared direct-drive generator for large wind turbines is introduced in this paper. Conventional Vernier-type machines and most of the direct-drive wind turbine generators use excessive amount of permanent magnet, which increases the overall cost and makes the manufacturing process challenging. In this paper, an electrically excited (PM_less) claw-pole type Vernier machine is presented. This new topology has the potential of reducing mass and cost of the generator, and can make the construction easy in manufacturing and handling. Analytical designs are verified using 3D finite-element simulations and several designs are evaluated to find the optimum design for a 7.5 MW, 12 rpm wind turbine application. It is shown, that the required torque can be achieved with an outer diameter of 7.5 m, and with a mass of 172 t (including the structural mass). The proposed generator is compared with commercial direct-drive generators, and it is found that the proposed generator has the highest torque density with 34.7 kNm/t.


An open source tool to estimate mass and efficiency of wind turbine power take-off systems
Keysan, Ozan (2013-12-01)
This paper presents mass and efficiency estimations for wind turbine drive-train components. Data from literature and commercial catalogues are collected to obtain trend lines for each component. Different gearbox and generator types are investigated as well as the bearing and the low-speed shaft. An open-source tool is presented to compare different power take-off options in terms of weight and efficiency. The datasets and the user interface made available as an open source tool and can be accessed at GitHub.
A Transverse Flux High Temperature Superconducting Generator Topology for Large Direct Drive Wind Turbines
Keysan, Ozan (2012-01-01)
The cost and mass of an offshore wind turbine power-train can be reduced by using high-temperature superconducting generators, but for a successful commercial design the superconducting generator should be as reliable as its alternatives. In this paper, we present a novel transverse flux superconducting generator topology which is suitable for low-speed, high-torque applications. The generator is designed with a stationary superconducting field winding and a variable reluctance claw pole motor for simplifie...
A micro power generator with planar coils on parylene cantilevers
Sari, Ibrahim; Balkan, Raif Tuna; Külah, Haluk (2008-06-25)
In this paper an electromagnetic vibration based micro power generator is presented. The proposed generator is composed of parylene cantilevers on which planar coils are fabricated. The system uses external vibrations to generate power by virtue of the relative motion between the cantilevers and a magnet. The parameters of the micro generator have been optimized for maximum output and it has been fabricated in micro scale. Initials tests show that 8.75 mV could be obtained from the proposed generator at a v...
A Modular Superconducting Generator for Offshore Wind Turbines
Keysan, Ozan; Mueller, Markus A (2013-05-01)
In this study, a new claw-pole type transverse flux superconducting generator topology is presented. The machine has a stationary superconducting field winding, which eliminates electrical brushes and cryocouplers. The machine is specifically designed for low-speed high torque applications such as large offshore wind turbines. The proposed machine is robust and has a modular structure.
A direct drive permanent magnet generator design for a tidal current turbine SeaGen
Keysan, Ozan; Markus, Mueller (2011-05-15)
In this study, the feasibility of a direct-drive permanent magnet generator for a tidal turbine power take-off system, namely MCT's SeaGen - the world's first full scale commercial tidal turbine- has been investigated. The investigated PM generator topology is called C-GEN which is an air-cored axial-flux generator developed in the University of Edinburgh. The C-GEN is prior to conventional PM generators by absence of magnetic attraction forces between rotor and stator, absence of cogging torque, ease of ma...
Citation Formats
R. Zeinali and O. Keysan, “A Rare-Earth Free Magnetically Geared Generator for Direct-Drive Wind Turbines,” ENERGIES, pp. 0–0, 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/48135.