Differential Coil, Solenoid Type, High Voltage Series Reactor

Abstract

Differential-coil, high-voltage series reactors respond quickly and reliably to current surges in electrical power systems (such as surges caused by shorted or downed lines). The reactors prevent voltage collapse and eliminate the possibility of wide area blackouts (major metropolitan areas or entire states).

We claim: 
     
         1 . An electromechanical short-circuit protector comprising:
 a first terminal and a second terminal, said terminals connected electrically so that a voltage applied across the terminals causes a current to flow from the first terminal to the second terminal;   a first conductive coil connected to the first terminal, said first conductive coil having a first number of turns and generating a first magnetic field when the current flows therethrough;   a second conductive coil connected to the second terminal, said second conductive coil having a second number of turns and generating a second magnetic field when the current flows therethrough, said second conductive coil electrically connected to said first conductive coil; and   a moveable element that is affected by the first magnetic field and the second magnetic field, wherein   an impedance between the first terminal and the second terminal assumes a first value when the current is below a predetermined level, and   the impedance between the first terminal and the second terminal assumes a second value when the current is above a predetermined level.   
     
     
         2 . The electromechanical short-circuit protector of  claim 1  wherein a first winding direction of the first conductive coil is different from a second winding direction of the second conductive coil. 
     
     
         3 . The electromechanical short-circuit protector of  claim 1  wherein the first magnetic field opposes and partially cancels the second magnetic field. 
     
     
         4 . The electromechanical short-circuit protector of  claim 1  wherein the first number of turns is different from the second number of turns. 
     
     
         5 . The electromechanical short-circuit protector of  claim 1 , further comprising:
 a third conductive coil connected to at least one of the first conductive coil and the second conductive coil, said third conductive coil having a third number of turns and wound in a different direction from at least one of the first conductive coil and the second conductive coil.   
     
     
         6 . The electromechanical short-circuit protector of  claim 1 , further comprising:
 a laminated steel frame surrounding the first and second conductive coils.   
     
     
         7 . A differential-coil, solenoid-type, high-voltage series reactor comprising:
 a first conductive coil wound in a first direction around a hollow tubular spool piece defining a winding axis;   a second conductive coil wound in a second, different direction around the winding axis, the first conductive coil connected electrically in parallel with the first conductive coil; and   a moveable magnetically-susceptible slug confined to travel through the hollow tubular spool piece along the winding axis, wherein   the differential-coil, solenoid-type, high-voltage series reactor has a first electrical impedance when the moveable magnetically-susceptible slug is at a first position; and   the differential-coil, solenoid-type, high-voltage series reactor has a second, higher electrical impedance when the moveable magnetically-susceptible slug is at a second, different position, and wherein   a position of the moveable magnetically-susceptible slug depends on a current through the differential-coil, solenoid-type, high-voltage series reactor.   
     
     
         8 . The differential-coil, solenoid-type, high-voltage series reactor of  claim 7  wherein the first conductive coil comprises 22-30 turns, and the second conductive coil comprises a different number of turns than the first conductive coil. 
     
     
         9 . The differential-coil, solenoid-type, high-voltage series reactor of  claim 7  wherein the first conductive coil and second conductive coil are wound from copper wire. 
     
     
         10 . The differential-coil, solenoid-type, high-voltage series reactor of  claim 7  wherein the moveable magnetically-susceptible slug is approximately 18 inches in diameter and approximately 60 inches in length. 
     
     
         11 . The differential-coil, solenoid-type, high-voltage series reactor of  claim 7  wherein the first conductive coil, the second conductive coil, and the moveable magnetically-susceptible slug are of approximately equal length. 
     
     
         12 . The differential-coil, solenoid-type, high-voltage series reactor of  claim 7  wherein moveable magnetically-susceptible slug approximately fills a portion of the hollow tubular spool piece that is surrounded by the first conductive coil.