Design And Measurement Of A Small Scale High Temperature Superconducting Linear Induction Motor Prototype

Most electric linear drives in the transportation industry nowadays are made of conventional copper wire coils along with the possible aid of ferromagnetic cores. High speeds can be conveniently obtained; however, some drawbacks still remain. The main shortfall of a linear motor, whether it be synchronous or inductive, short stator or long stator, is the magnetic saturation of its ferromagnetic cores which ultimately saturates generation of thrust. Most research has been devoted toward reaching higher and higher thrust densities; however, they mostly aim toward the optimization of its key components such as its coil parameters, winding, positioning and geometry. In contrast, this work focuses on a new concept so that higher thrust densities can be obtained.This work presents the design, construction, computing, experimental testing and data analysis of a linear induction motor that employs a superconducting secondary in the locked-mover state. Given the near zero resistance superconducting properties of the secondary, large amounts of current are able to be induced which are harnessed to generate thrust. The primary of the studied linear motor is a conventional flat, single sided and three-phased made of copper wound coils and a silicon steel armature. The secondary also uses a flat geometry consisting of up to four coils made of2nd generation YBCO coated conductor wire connected in series. Ferromagnetic materials made of iron and Permendur50were also used as cores of the superconducting coils for comparison.The obtained experimental results were better than expected; a maximum thrust of120N was achieved, which was equivalent to a thrust density of123.45N/m, or123x times better than its copper wound counterpart. The slip versus thrust curve was measured to be different than conventional linear motors which Ⅰ explain it by taking into account the capacitive component inherent in Type-Ⅱ superconductors. The evidence obtained from the experiments establish the fact that with the aid of superconducting components, the present thrust density limit in linear motor technology can be far surpassed allowing for the possibility of breaking the present ground speed record of581km/h.