Electro-magnetically enhanced current interrupter

• US 20060119996A1
• Filed: 01/27/2006
• Published: 06/08/2006
• Est. Priority Date: 11/06/2003
• Status: Active Grant

• Current Assignee: Pratt & Whitney Canada Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Pratt & Whitney Canada Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Dooley, Kevin Allan
• Granted Patent: US 7,315,228 B2
• Time in Patent Office: Days
• US Class Current: 361/19
• CPC Class Codes: H01H 2085/386 with magnetic or electrodynamic arc-blowing
• CPC Class Codes: H01H 85/06 characterised by the fusible material H01H85/11 takes precedence
• CPC Class Codes: H01H 85/38 Means for extinguishing or suppressing arc by powder filling H01H85/18; by mechanical tension applied to fusible member H01H85/36

Abstract

The present invention provides an apparatus and method of interrupting the current in a circuit wherein the magnetic pressure induced by current flow through a conductor causes the conductor to flow and thereby open the associated circuit. Magnetic pressure may be derived from Lorenz equations. Gravity is not relied upon to cause the conductor material to flow. The invention may be used in circuits having high currents relative to conductor size and material selection.

Claims

1. A method of providing a current interrupter having at least a conductor adapted to be physically altered to thereby open an associated circuit when a threshold current from the circuit passes through the conductor, the method comprising the steps of:

selecting a conductor material, the material having a flow temperature above which the conductor flows;

selecting a conductor cross-section area; and

determining said threshold current,

wherein the threshold current is sufficient to raise a conductor temperature to at least the flow temperature at a location corresponding to the cross-section area, and wherein the threshold current induces sufficient pressure in the conductor to cause a sufficient amount of the conductor material to cause an open circuit.

2. The method of claim 1 further comprising the step of selecting said induced pressure to at least overcome a pressure loss associated with the conductor flowing.

3. A method of providing a current interrupter comprising the steps of:

a) selecting an interrupter configuration having a conductor;

b) selecting a material for the conductor, a cross-sectional area for the conductor and a desired threshold current at which current interruption is desired;

c) determining a temperature above which the conductor is in a flowable state;

d) determining a magnetic pressure associated with the threshold current passing through the conductor;

e) determining a pressure required to cause the conductor to flow in the interrupter configuration when the conductor is in the flowable state;

f) comparing the magnetic pressure with the pressure required to determine if the magnetic pressure exceeds the pressure required; and

then

g) providing an interrupter according to the selections made in steps a) and b),

wherein in step f) if the magnetic pressure does not exceed the pressure required then at least one of steps a) and b) and at least one of steps c), d) and e) and at least step f) are iterated until a condition that the magnetic pressure exceeds the pressure required is met, and wherein the condition is met before step g) is performed.

4. A method of interrupting a current in a circuit when a threshold current passes through a conductor of the circuit, the method comprising the steps of:

providing a conductor made of a conductor material;

providing a current through the conductor, wherein the current is sufficient to raise the conductor temperature to a temperature at which the conductor material flows, and wherein the current is sufficient to induce a pressure large enough to cause the conductor to flow and thereby interrupt the circuit.

5. A method of interrupting a current in a circuit when a threshold current passes through a conductor of the circuit, the method comprising the steps of:

providing a threshold current through the conductor;

providing a flowable state to the conductor; and

providing sufficient magnetic pressure in the conductor to cause the conductor flow accordingly and thereby interrupt the circuit, wherein the magnetic pressure is induced by current passing through the conductor.

6. The current interrupter of claim 5 wherein the magnetic pressure exceeds 0.1 psi.

7. The current interrupter of claim 6 wherein the magnetic pressure exceeds 0.5 psi.

8. The current interrupter of claim 7 wherein the magnetic pressure exceeds 1 psi.

9. The method of claim 5, wherein the step of providing the threshold current causes an associated temperature rise in the conductor, and wherein the temperature rise causes the step of providing the flowable state to the conductor.

10. The method of claim 5 wherein material from the flowing conductor is captured in a reservoir.

11. The method of claim 5, wherein the conductor flows substantially independent of a gravitational effect on the flowable conductor.

12. A method of providing a current interrupter for a circuit, the method comprising the steps of:

determining a desired threshold current;

selecting a conductor material having a flow temperature above which the conductor will flow;

selecting a conductor cross-sectional size;

determining a magnetic pressure associated with the threshold current, the conductor material and the conductor cross-sectional size;

determining a threshold conductor temperature resulting from the threshold current passing through the conductor material;

ensuring the conductor threshold temperature exceeds the conductor flow temperature; and

ensuring that the magnetic pressure is sufficient when the threshold current passes through the conductor to thereby force the conductor material to flow to interrupt the circuit.