Thermal, electrical and magnetic behaviour of a superconducting winding

We have developed a digital computation of the time dependences of losses and of the temperature in a composite, and in a flat braided cable, submitted to any space and time-variations of the magnetic induction and to any time-variations of current and of cooling conditions. Experimental and calculated losses, in the case of a composite submitted to a rotating magnetic induction, are in good agreement within about 5 % to 10 %. This digital computation have also been used to design an optimum flat braided cable for the rotor of a 250 MW superconducting A.C. generator which may undergo a cleared short circuit followed by a fault elimination without quenching. Time variations of the ratio of the current to the critical one, of the temperature and of the losses in the cable during the fault are presented.