Superconducting winding are enabling for the development of the highest power density motors and generators for aircraft use. Some of the most promising materials are YBCO coated conductors, with their $T_{c}$ of 90 K, and useful operational range up to 77 K. NASA has preliminary designs for motors with Cu stators and coated conductor based rotor coils, and is considering the type of coil assembly for the YBCO windings. A key aspect of any YBCO coil is how to protect the coil from quench in the case of the initiation of a normal zone. The growth of the normal zone is several orders of magnitude lower than that of LTS conductors, increasing the potential for coil damage. On the other hand, the much larger minimum quench energy (MQE) makes these events much less likely. The use of a no insulation (NI) method to protect again such damage has been implemented in a number of solenoidal type coils, where a relatively low layer-to-layer contact resistance allows for current redistribution and coil protection in the case of a normal zone. Here we consider its application to racetrack coils. We have modelled a coated conductor wound racetrack coil and investigated its current sharing using finite element methods. A small defect 1 mm in length is assumed in the YBCO, and the level of current sharing is explore as a function of interlayer contact resistance. A clear transition from a high level of current sharing to a low level of current sharing is seen with the change in contact resistance.


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    Title :

    Influence of Electrical Turn-to-Turn Sharing on Quench Protection in Superconducting Coils for Very High Power Density Motors for Hybrid-Electric Aircraft


    Contributors:


    Publication date :

    2019-08-01


    Size :

    7779307 byte




    Type of media :

    Conference paper


    Type of material :

    Electronic Resource


    Language :

    English