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.
AC-losses in multifilamentary superconductors at technical frequencies
Multifilamentary superconductors exposed to an alternating field of small amplitude but in the technical frequency range as in a rotor of a superconducting generator show a characteristic dependence of losses on frequency. Shielding of the conductor by the induced currents is shown to be relevant. In a twisted cylindrical multifilamentary conductor the shielding currents are calculated and formulas for the hysteretic loss and eddy current loss are given as function of frequency and time constant τ of the conductor. It is shown, that a long twist length can give lower losses than a short one.
Flat guidance schemes for magnetically levitated high‐speed guided ground transport
A magnetically levitated high‐speed vehicle requires a noncontact guidance system. Guideway configurations are discussed, and the possibility of achieving guidance from a flat surface is investigated. A vehicle with electrodynamic suspension and linear synchronous motor propulsion carries superconducting magnets which may be used for guidance purposes. Eight possible ``flat'' guidance mechanisms are examined. It is shown that the interaction between vehicle‐borne magnets and levitation strips or linear synchronous motor (LSM) windings cannot provide adequate restoring forces. Additional conductors are therefore required for guidance. The use of either vertically mounted rectangular loops or horizontally mounted null‐flux (NF) loops under either the levitation magnets or propulsion magnets is therefore examined. The most promising system involves the interaction between propulsion magnets and horizontal NF loops, with the interaction between propulsion magnets and the edges of the levitation strips providi...