Design and Analysis of 10 MW Class HTS Exciting Double Stator Direct-Drive Wind Generator With Stationary Seal

The superconducting (SC) generators are expected to have a promising application for offshore wind generation due to the merits of high power density and high efficiency over the conventional generators. In this paper, a 10-MW conceptual high temperature superconducting (HTS) exciting double stator direct-drive wind generator (HTS-DSDDG) with the stationary seal is proposed and investigated. The proposed HTS-DSDDG has two spatially independent stators: to place HTS field windings and copper armature windings, respectively. Thus, it realizes the stationary seal of the cooling system and removes brushes and slip rings and the other additional excitation device; hence offering the advantages of the high reliability and the low operation & maintenance cost. The main design considerations and the initial design specifications of the 10 MW HTS-DSDDG are given in detail. Furthermore, the electromagnetic characteristics of the HTS- DSDDG under no-load, rated load, and three-phase short-circuit fault conditions are analyzed by the finite element method (ELM). Subsequently, its size, weight, and cost are compared with the existing conceptual 10 MW wind generators. The results reveal that the HTS-DSDDG has excellent electromagnetic performances, such as good sinusoidal voltage, low cogging torque, and torque ripple; besides, its output power per volume is twice than that of the permanent magnet direct-drive generator (PMDDG), being comparable to that of the existing conceptual MgB2-HTS direct-drive generators.