Analytical Calculation of the Instantaneous Power in a Current Carrying Superconducting Tube With ${J}_{C}({B})$

B Douine,J Leveque,D Netter,K Berger,J.E Pienkos

doi:10.1109/tasc.2008.2000906

Abstract

To use high-Tc superconductors for alternating current transport, it is important to evaluate AC losses. The influence of Jc ( B ) on the self field losses in a superconductive tube fed by a transport current in incomplete penetration is studied for two reasons. First, superconducting power cables have a geometry that resembles a tube and second, for high-temperature superconductors, the variation of Jc ( B ) is important especially for low magnetic fields like self field. An analytical calculation of the distribution of the magnetic field B ( r , t ) by using a linearized law Jc ( B ) is presented. From B ( r , t ) one deduces J ( r , t ) and E ( r , t ) . The analytical expressions of those were used to calculate the analytical instantaneous power p ( t ). The losses in the superconducting tube are the average value of p ( t ) . They are numerically calculated and compared with the measurements taken on a sample whose characteristic Jc ( B ) was previously measured. With the linear model, the calculated losses are closer to the measured losses than for the Bean model, but the Jc ( B ) identification remains the main problem.

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