抄録
Since wind power generation systems operate at very low rotation speeds, synchronous generators that apply hightemperature superconductors (HTS) to the field windings provide merits such as significant reductions in size/weight and improved rating/partial load efficiency. In this study, a conceptual structure of the HTS generators with a salient-pole iron rotor and racetrack-shaped HTS field coils was proposed. The electrical designs of the large-scale salient-pole HTS generators were prepared using the design program developed. In the design, operating field current was determined from the allowable HTS coil heat loss, which was calculated using three-dimensional magnetic flux analysis. The influence of magnetic flux density in rotor iron cores and the number of poles on elements of main-generator performance such as generator weight, generator efficiency and the required HTS length were clarified. Furthermore, the suitable stator outer diameter for a given output power was studied in order to obtain satisfactory generator performance. Machine parameters were determined considering these results, and electrical designs of 5-10 MW HTS generators were created under an operating temperature of 77 K.
