Patent EP-2717277-A1 (EP)
Inventor: SCHLENGA KLAUS
IPC: H01F6/00
Filed: 2013-10-02
Abstract: The inductive leakage current limiter comprises a normal-conducting primary coil assembly (2) with coils (3), and a super-conducting short-circuited secondary coil assembly (4). The primary and secondary coil assemblies are coaxially arranged and nested to each other. The primary coil assembly comprises a first and a second coil section. The coils of the first coil section are radially arranged inside the secondary coil assembly, and the coils of the first coil section are radially arranged radially outside the secondary coil assembly. The inductive leakage current limiter comprises a normal-conducting primary coil assembly (2) with coils (3), and a super-conducting short-circuited secondary coil assembly (4). The primary and secondary coil assemblies are coaxially arranged and nested to each other. The primary coil assembly comprises a first coil section and a second coil section. The coils of the first coil section are radially arranged inside the secondary coil assembly, and the coils of the first coil section are radially arranged outside the secondary coil assembly. The secondary coil assembly is arranged between an innermost layer of coils of the first coil section of the primary coil assembly and an outermost layer of coils of the second coil section of the primary coil assembly. The coils of the primary coil assembly are uniformly divided into the first and second coil sections. The secondary coil assembly comprises superconducting, annular closed single-winding coils and first and second coil sections. The first coil section of the secondary coil assembly is radially arranged inside the second coil section of the secondary coil assembly. A normal conducting shunt assembly is radially provided between the first coil section and the second coil section of the secondary coil assembly. The shunt assembly comprises closed shunt rings provided between the first coil section and the second coil section of the secondary coil assembly. An inner shunt ring is electrically connected to the first coil section of the secondary coil assembly, and an outer shunt ring is electrically connected with the second coil section of the secondary coil assembly. The first and second coil sections of the secondary coil assembly have a different number of super-conducting, annular closed sing-winding coils. The primary and secondary coil assemblies are symmetrically rotated with respect to a vertical axis. The first coil section of the primary coil assembly comprises a ferromagnetic core (8). The secondary coil assembly extends in an axial direction as far as the primary coil assembly. The sections of the primary coil assembly extend in the axial direction with different extents. The secondary coil assembly is arranged in a cryostate (5) so that the first and second coil sections of the primary coil assembly and the cryostate are positioned and dimensioned in the secondary coil assembly. Gaps are arranged in the radial direction between opposite sides of the secondary coil assembly. The gaps between the first and second coil sections of the primary coil assembly are less than half of a sum of the primary and secondary coil assemblies. A thickness of the gaps of the primary or secondary coil assembly is arranged in a radial direction. The primary coil assembly has N sections, where N is expressed as given in the specification. The secondary coil assembly has N-1 sections, where N is 3 or 4.