Patent NZ-598388-A (NZ)
Title: Method and apparatus for protecting power systems from extraordinary electromagnetic pulses
Inventor: BIRNBACH CURTIS A
IPC: H01H83/10
Filed: 2010-03-09
Abstract: A bidirectional high-voltage cold-cathode field-emission bi-directional vacuum electron tube, comprises a) a cylindrical inner electrode encircled by a first cylindrical grid, in turn encircled by a second cylindrical grid, in turn encircled by a cylindrical outer electrode; the inner and outer electrodes and the first and second grids sharing a common main axis; b) the inner and outer cylindrical electrodes respectively functioning bidirectionally, as either a field emission cathode or an anode, depending on the instantaneous polarity of the signal applied across the electrodes; c) the radial spacing from the inner electrode to the first grid is such as to create therebetween a circular waveguide supporting the transverse electromagnetic mode; and the spacing between the second grid and the outer electrode is such as to create therebetween a circular waveguide supporting the transverse electromagnetic mode; and d) the radial spacing between the first grid and the second grid is sufficient to prevent flashover between the first and second grids at an intended operating voltage. A method and an apparatus for preventing an extraordinary electromagnetic pulse from reaching and rendering inoperative a magnetic-winding containing component of an electrical power system are disclosed. The component is located in a conductive path of the system that receives the pulse and the apparatus comprises a) means for detecting the presence of the pulse in the conductive path prior to the pulse reaching and rendering inoperative the electrical component; and b) means for diverting the pulse around the electrical component by creation of a low inductance, high current capacity short-circuit across the electrical component so as to thereby collapse the magnetic field in the winding before the pulse can reach and render the electrical component inoperative. A method and an apparatus for preventing an extraordinary electromagnetic pulse from reaching and rendering inoperative an electrical component of an electrical power system that is normally at a DC voltage, which component is located in a conductive path of the system that receives the pulse are disclosed. The apparatus comprises, a) means for detecting the presence of the pulse in the conductive path prior to the pulse reaching and rendering inoperative the electrical component; and b) means for diverting the pulse around the electrical component by creation of a unidirectional low inductance, high current capacity short-circuit across the electrical component, before the pulse can reach and render the electrical component inoperative. The low inductance, high current capacity short-circuit comprises i) a high-voltage cold-cathode field-emission vacuum electron tube including a cylindrical inner electrode, at least one cylindrical grid encircling the inner electrode, and a cylindrical outer electrode encircling the at least one grid; the inner and outer electrodes and the at least one grid sharing a common main axis; ii) the radial spacing from either the inner electrode or the outer electrode to an adjacent grid is such as to create therebetween a circular waveguide supporting the transverse electromagnetic mode. The low inductance, high current capacity short-circuit can also comprises a switch mounted on an self-supporting insulated conductor formed from an elongated conductor having a cross section along the length of the conductor that defines a flat rectangular solid with radiused edges; and d) one end of the self-supporting conductor is connected to earth ground.