Power losses are an important phenomenon in 2nd type superconductors. Precise evaluation ofpower losses in superconducting coils is crucial for the design of novel machines such assuperconducting motors or generators. Although AC losses are relatively easy to measurewith electrical methods, it is more difficult to measure power losses in the DC mode, inducedby varying external magnetic fields, such as occur in a real operating environment. Especiallythe problematic one could be the direct-drive wind generator, where several elementsintroduce nonsynchronous disturbances to the magnetic fields. Modelling had been carriedout by numerous authors1-4 in order to estimate the power losses in 2G HTS coils undervarious external DC or ripple fields; however experimental work in the area is less commondue to the difficulty of conducting experiments and special equipment requirements. In thispaper, power losses are experimentally measured by the calorimetric method.
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