SHUNT PROTECTION FOR SUPERCONDUCTING MAGLEV MAGNETS
Abstract Closely coupled, short-circuited shunt coils are proposed for quench protection of super-conducting Maglev magnets which use high resistance, matrix composite conductors. It is shown that, by suitable design, the shunts can reduce ac losses and that the changing currents during magnet energization or vehicle lift off and landing can be tolerated.
Superconducting windings with parallel connected sections
A theoretical treatment of superconducting magnets with parallel connected sections has been performed. The method and results of calculation and optimization of magnet geometric and electromagnetic parameters is described. It is shown that by selecting the dimensions of sections with due regard for the superconductor critical current dependence on the magnetic field the conductor consumption can be markedly reduced. Main regularities of the quenching process in a sectioned winding are found. It is shown that segmentation improves the reliability of winding, especially in the case when the normal zone is localized in one section of the magnet. Criteria of segmented magnet reliability based on the parameters of constituent modules are found.
Measurement of ac losses in multifilament super-conducting wires at frequencies between 1 and 100 Hz
Abstract Calorimetric measurements of the losses of a superconducting coil wound from a moderately twisted multifilamentary superconducting wire have been made with a coil current consisting of a direct current and a superimposed ac component at frequencies between 1 and 100 Hz. There exists a frequency range where the loss per cycle decreases with increasing frequency. Magnetization measurements on a sample of the multi-filament wire in an applied inductance B = B s + B 0 sin ω t confirmed the results of the calorimetric measurements and indicated that with increasing frequency the flow of magnetic flux into and out of the composite during a cycle becomes more and more diminished.