Resistive fault current limiter
AssigneeAmerican Superconductor Corporation
InventorsSwarn S. Kalsi, Gregory L. Snitchler
Life of this patent
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Abstract
An electric coil includes bifilar pancake coils electrically connected to an adjacent pancake coil so that current flowing in adjacent turns of adjacent pancake coils flows in opposite directions at all radial region of the coil assembly. The superconducting fault current limiter is configured to provide a minimized inductance and low resistance in a normal state of operation. On the other hand, when a fault current exceeds a predetermined threshold, the resistance increases to a level sufficient for limiting the flow of fault current to a desired level until a circuit breaker connected within the electrical system opens the circuit.
Claims31
A coil assembly having a longitudinal axis, the coil assembly comprising a plurality of bifilar pancake coils disposed in a stack arrangement along the longitudinal axis, each coil including a first pair of conductive winding sections joined along an innermost radial region of the coil, wound together, one over the other, radially outward and around the longitudinal axis, each pancake coil electrically connected to an adjacent pancake coil so that current flowing in adjacent turns of adjacent pancake coils flows in opposite directions at all radial regions of the coil assembly.
A fault current limiter assembly comprising:
- a support structure having a central axis and a plurality of support members, each having a longitudinal axis radially spaced a predetermined distance from the central axis;
- and
- a plurality of coil assemblies, each disposed along a corresponding one of the longitudinal axis of the support members, each including:
- a plurality of bifilar pancake coils disposed in a stack arrangement along the longitudinal axis, each coil including a first pair of conductive winding sections joined along an innermost radial region of the coil, wound together, one over the other, radially outward and around the longitudinal axis, each pancake coil electrically connected to an adjacent pancake coil so that current flowing in adjacent turns of adjacent pancake coils flows in opposite directions at an outermost radial region of the coil assembly.
A method of providing a fault current limiting coil having a longitudinal axis, the method comprising:
- positioning a plurality of bifilar pancake coils in a stack arrangement along the longitudinal axis of the fault current limiting coil, each pancake coil including a first pair of conductive winding sections joined along an innermost radial region of the coil, wound together, one over the other, radially outward and around the longitudinal axis;
- and
- electrically connecting adjacent pancake coils so that current flowing in adjacent turns of adjacent pancake coils flows in opposite directions.
Dependencies are inferred from the claim text.