Fabrication of a Scaled MgB2 Racetrack Demonstrator Pole for a 10-MW Direct-Drive Wind Turbine Generator

Abstract

Abstract-Field windings made of MgB2 wires or tapes are considered for their potential to reduce volume, weight and cost of large offshore wind turbine generators. To gain experience of how to use this relatively new material in full-scale generators, tests of different winding methodologies and techniques are needed. In this paper, we describe in detail the steps used to wind a racetrack coil with a length of 1 m and a width of 0.5 m out of 4.5 km of MgB2 superconducting tape. The width corresponds to a full-scale pole of a 10 MW generator, whereas the length of the straight section is shorter than the corresponding full-scale pole. The coil was built up of 10 double pancake coils. Each double pancake coil was wet-wound using a semi-automatic winding process, where Stycast 2850 was applied directly to the MgB2 tape without any other dedicated electrical insulation. The strengths and weaknesses of the winding process are discussed and compared to the dry-winding method. 

Evaluation of a solid nitrogen impregnated MgB2 racetrack coil

“…In fact, more powerful turbines are required to raise wind power production and to minimize overall cost per unit generated energy from a windmill [2]. To meet this demand, off-shore wind turbine generators of up to 10-MW capacity with superconducting technology are being considered [3][4][5][6][7][8][9][10][11][12][13].…”

“…Several reviews have been published on the use of different types of superconductors for wind turbine application [6,15]. Among the commercially available superconductors, magnesium diboride (MgB2) with critical temperature (Tc) of 39 K has good potential to employ in rotating machines [6,10,12,13,16]. This is mainly due to its performancecost ratio A c c e p t e d M a n u s c r i p t at around 20 K compared to high-temperature superconductors (HTS), and its availability in long piece-lengths [6,14,17].…”

“…The INWIND.EU project, funded under the FP7 framework, reported the design and winding aspects of an MgB2 racetrack coil for a direct-drive 10-MW wind turbine generator pole [2,8,13]. Sarmiento et al reported the design and evaluation of a fullscale MgB2 coil (one double pancake) for the 10-MW SUPRAPOWER wind turbine generators [10].…”

“…In fact, more powerful turbines are required to raise wind power production and to minimize overall cost per unit generated energy from a windmill [2]. To meet this demand, off-shore wind turbine generators of up to 10 MW capacity with superconducting technology are being considered [3][4][5][6][7][8][9][10][11][12][13]. Superconducting windings can produce strong magnetic fields due to their ability to carry high current without any loss compared to copper (Cu) conductors.…”

“…Later, the same group also fabricated several racetrack coils using fully formed MgB 2 wires for the development of a 2 MW superconducting turbogenerator cooled by liquid hydrogen [22]. One of the coils fabricated using monofilamentary MgB 2 wire attained I c of 260 A in self-field at 20 K. The INWIND.EU project, funded under the FP7 framework, reported the design and winding aspects of an MgB 2 racetrack coil for a direct-drive 10 MW wind turbine generator pole [2,8,13]. Sarmiento et al reported the design and evaluation of a full-scale MgB 2 coil (one double pancake) for the 10 MW SUPRAPOWER wind turbine generators [10].…”