Mechanically variable high reactive power inductor for testing capacitive loads,such as high voltage electrical power transmission cables

Claim 2

An accurately mechanically variable high reactive power inductor for testing large capacitance loads, such as highvoltage electrical power transmission cables, large capacitors, groups of capacitors and the like, comprising a rigid high strength frame defining an inductor spacE, a high reactive power variable inductor located in the inductor space and formed of a magnetic core and an electrical winding magnetically coupled to the core, said magnetic core being formed of upper and lower separable core segments, the lower core segment being stationary and supported by the bottom of the frame and the upper core segment being vertically movably suspended above the lower core segment from the upper part of the frame, a plurality of nonrotating feed screws supporting the upper core segment and extending vertically upward therefrom, low friction feed members interposed between the respective feed screws and the upper frame part and operatively engaging screw threads on the feed screws to produce vertical movement of said feed screws and upper core segment upon rotation of said feed members to control the gap size between the upper and lower core segments, said feed members being arranged to maintain low friction rotating capability under vertically directed forces produced by the weight of the upper core segment and by electromagnetic forces generated between the upper and lower core segments, drive means operatively coupled to each of said feed members for synchronous rotation thereof to simultaneously control the vertical movement of said feed screws, sensing means for sensing a preselected separation of the upper core segment from the lower core segment, and speed control means responsive to said sensing means for correspondingly altering the effective driving speed of said drive means.

Claim 3

The high reactance power accurately variable inductor as claimed in claim 1 wherein said sensing means further includes an enlarged actuator member vertically adjustably mounted on one of said feed screws to move therewith, and a switch mounted to the frame in operative relationship with the path of movement of said enlarged actuator member as said feed screw moves up and down, said speed control means being responsive to said switch.

Claim 4

An accurate mechanically variable high reactive power inductor for testing large capacitance loads, such as high-voltage electrical power transmission cables, large capacitors, groups of capacitors, and the like, in a resonance circuit effectively including the capacitance of the load and the inductance of the inductor, comprising a high strength rigid frame, upper and lower magnetic cores mounted in the frame, said cores being separable to form a variable gap, at least one electrical winding magnetically coupled to the cores to provide a variable inductance which is varied by changing the separation between the cores, nonrotating feed screws connected to the upper core and extending upwardly therefrom, low-friction feed members interposed between the feed screws and the upper portion of the frame and operatively engaging the feed screws to produce vertical movement of the feed screws and upper core upon rotation of the feed members to control gap size between the upper and lower cores, channel-iron clamping elements gripping said upper and lower cores, with said channel elements arranged with the web portion adjacent said cores, V-shaped clamps located in the channels with the open end of the V-shaped clamps facing into the channel to operatively contact the flange and the web of said channel at clamping locations, and bolts interconnecting oppositely located V-shaped clamps to rigidly and securely clamp said cores between the channels to form a rigid high-power variable inductor capable of withstanding large magnetic forces with small deformation.

Claim 5

An accurate mechanically variable high reactive power inductor for testing large capacitance loads, such as high-voltage electrical power transmission cables, large capacitors, groups of capacitors, and the like, in a resonance circuit effectively including the capacitance of the load and the inductance of the inductor, comprising a high strength rigid frame, upper and lower magnetic cores mounted in the frame, said cores being separable to form a variable gap, at least one electrical winding magnetically coupled to the cores to provide a variable inductance which is varied by changing the separation between the cores, nonrotating feed screws connected to the upper core and extending upwardly therefrom, low-friction feed members interposed between the feed screws and the upper portion of the frame and operatively engaging the feed screws to produce vertical movement of the feed screws and upper core upon rotation of the feed members to control gap size between the upper and lower cores, channel-iron clamping elements gripping said upper and lower cores, with said channel elements arranged with the web portion adjacent said cores, V-shaped clamps located in the channels with the open end of the V-shaped clamps facing into the channel to operatively contact the flange and the web of said channel at clamping locations, and bolts interconnecting oppositely located V-shaped clamps to rigidly and securely clamp said cores between the channels to form a rigid high-power variable inductor capable of withstanding large magnetic forces with small deformation.

Claim 6

The mechanically variable high reactive power inductor as claimed in claim 3 wherein said channel-irons are horizontally disposed with said V-shaped clamps being vertically arranged to contact said flanges near the intersection with the web.

Claim 7

In an accurate mechanically variable high reactive power inductor for testing large capacitance loads, such as high-voltage electrical power transmission cables, large capacitors, groups of capacitors, and the like, With an inductor having separable magnetic cores wherein driving means control vertical motion of a movable magnetic core relative to a second magnetic core to form a variable gap for varying the inductance of a winding magnetically coupled to the cores the improvement comprising means for sensing a preselected magnitude of the gap between the first and second cores and speed control means operatively associated with the driving means for reducing the speed of vertical motion of the first core when the size of the variable gap has been reduced to a predetermined size.

Claim 8

In an accurate mechanically variable high reactive power inductor for testing large capacitance loads, such as high-voltage electrical power transmission cables, large capacitors, groups of capacitors, and the like, With an inductor having separable magnetic cores wherein driving means control vertical motion of a movable magnetic core relative to a second magnetic core to form a variable gap for varying the inductance of a winding magnetically coupled to the cores the improvement comprising means for sensing a preselected magnitude of the gap between the first and second cores and speed control means operatively associated with the driving means for reducing the speed of vertical motion of the first core when the size of the variable gap has been reduced to a predetermined size.

Claim 9

The mechanically variable inductor as claimed in claim 5 wherein said speed control means further includes a first shaft rotated by the driving means, first and second clutches, said clutches being alternatively operatively actuated by the sensing means with the inputs of the clutches rotationally driven by said first shaft, a common rotating drive member coupled to the movable core for producing motion thereof, first and second speed determining means respectively operatively driven by the first and second clutches for producing a rotation of said common rotating drive member at respectively high and low speeds.

Claim 10

The mechanically variable inductor as claimed in claim 6 wherein said first and second clutches are coaxially disposed with said first shaft, with said first and second speed determining means comprising first and second sprocket and chain drives with said sprockets selectively sized to provide the predetermined speed levels.

Claim 11

The mechanically variable inductor as claimed in claim 5 and further including means for sensing the closure of the gap between said first and second cores for terminating motion of said movable core by said drive means.

Claim 12

An accurate mechanically variable high reactive power inductor for testing large capacitive loads, such as high-voltage electrical transmission cables, large capacitors, assemblies of capacitors, and the like, comprising a frame, first and second separable magnetic cores mounted on the frame, at least one electrical winding magnetically coupled to the cores, a plurality of feed screws connected to one of said cores and extending upwardly from said one core to produce a controlled separation of the cores to form a variable gap therebetween for varying the inductance of the winding, a plurality of feed members positioned above said one core and operatively interposed between the respective feed screws and the frame, means for simultaneously driving said feed members to produce motion of the feed screws for controlled variation of the gap between the cores with downward motion of said one core producing closure of said gap and a core gap closure sensor operatively engaged with one of said feed members, said core gap closure sensor controlling said driving means and being operatively located to sense axial motion of its associated feed member in an upward direction away from the core upon closure of the gap for stopping said driving means.

Claim 13

An accurate mechanically variable high reactive power inductor for testing large capacitive loads, such as high-voltage electrical transmission cables, large capacitors, assemblies of capacitors, and the like, comprising a frame, first and second separable magnetic cores mounted on the frame, at least one electrical winding magnetically coupled to the cores, a plurality of feed screws connected to one of said cores and extending upwardly from said one core to produce a controlled separation of the cores to form a variable gap therebetween for varying the inductance of the winding, a plurality of feed members positioned above said one core and operatively interposed between the respective feed screws and the frame, means for simultaneously driving said feed members to produce motion of the feed screws for controlled variation of the gap between the cores with downward motion of said one core producing closure of said gap and a core gap closure sensor operatively engaged with one of said feed members, said core gap closure sensor controlling said driving means and being operatively located to sense axial motion of its associated feed member in an upward direction away from the core upon closure of the gap for stopping said driving means.

Claim 14

An accurately mechanically variable high reactive power inductor for testing capacitive loads comprising a rigid high strength frame defining an inductor space, a high reactive power variable inductor located in the inductor space and formed of a magnetic core and at least one electrical winding magnetically coupled to the core, said magnetic core being formed of upper and lower separable core segments, the lower core segment being stationary and supported by the bottom of the frame and the upper core segment being vertically movably suspended above the lower core segment from the upper part of the frame, a plurality of nonrotating feed screws supporting the upper core segment and extending vertically upward therefrom low friction feed members interposed between respective the feed screws and the upper frame part and operatively engaging screw threads on the feed screws to produce vertical movement of said feed screws and upper core segment upon rotation of said feed members to control the gap spacing Between the upper and lower core segments, said feed members being arranged to provide low friction rotating capability under vertically directed forces produced by the weight the upper core segment and by the electromagnetic attraction forces between the upper and lower core segments, drive means operatively coupled to each of said feed members for synchronous rotation thereof to simultaneously control the vertical movement of said feed screws, and speed control means associated with said drive means for slowing the speed of movement of the upper core segment when the spacing between said core segments is reduced below a predetermined level.

Claim 15

An accurately mechanically variable high reactive power inductor for testing capacitive loads comprising a rigid high strength frame defining an inductor space, a high reactive power variable inductor located in the inductor space and formed of a magnetic core and at least one electrical winding magnetically coupled to the core, said magnetic core being formed of upper and lower separable core segments, the lower core segment being stationary and supported by the bottom of the frame and the upper core segment being vertically movably suspended above the lower core segment from the upper part of the frame, a plurality of nonrotating feed screws supporting the upper core segment and extending vertically upward therefrom low friction feed members interposed between respective the feed screws and the upper frame part and operatively engaging screw threads on the feed screws to produce vertical movement of said feed screws and upper core segment upon rotation of said feed members to control the gap spacing Between the upper and lower core segments, said feed members being arranged to provide low friction rotating capability under vertically directed forces produced by the weight the upper core segment and by the electromagnetic attraction forces between the upper and lower core segments, drive means operatively coupled to each of said feed members for synchronous rotation thereof to simultaneously control the vertical movement of said feed screws, and speed control means associated with said drive means for slowing the speed of movement of the upper core segment when the spacing between said core segments is reduced below a predetermined level.

Claim 16

An accurately mechanically variable high reactive power inductor as claimed in claim 10, in which a gap closure sensor is provided for sensing upward motion of one of said feed members occurring upon closure of the gap between the upper vertically movable core segment and the lower stationary core segment.

Claim 17

An accurately mechanically variable high reactive power inductor as claimed in claim 1, in which said sensing means include an enlargement member mounted upon one of said feed screws at a predetermined position and switch means mounted upon said frame at a predetermined position to be actuated by said enlargement member upon occurrence of said preselected separation of said upper core segment from said lower core segment.

Claim 18

An accurate mechanically variable high reactive power inductor for testing large capacitance loads, such as high-voltage electrical power transmission cables, large capacitors, groups of capacitors, and the like, in a resonance circuit effectively including the capacitance of the load and the inductance of the inductor, comprising a high strength rigid frame, upper and lower magnetic core segments mounted in the frame, said core segments being U-shaped and being positioned with the ends of their legs in opposed relationship defining a pair of gaps therebetween, said upper core segment being vertically movable to vary the size of said gaps, a pair of electrical windings surrounding the respective legs of said core segments and the variable gaps to provide a variable inductance which is varied by changing said variable gaps, a pair of clamping elements extending along opposite sides of said upper core segment for ripping said upper core segment, a pair of heavy crossmembers extending across said upper core segment and extending outwardly beyond opposite sides thereof, said heavy crossmembers being secured to said clamping elements, a nonrotating feed screw secured to the outer end of each of said crossmembers and extending upwardly therefrom, low-friction feed members interposed between the respective feed screws and the upper portion of the frame and operatively engaging the feed screws to produce vertical movement of the feed screws and the upper core segment upon rotation of the feed members to control the gap size between the legs of the upper and lower core segments, drive means operatively coupled to each of said feed members for producing simultaneous and equal effective rotation thereof, said drive means being changeable in effective driving speed, sensing means mounted upon the upper portion of the frame and responsive to the vertical movement of one of said feed screws, and said sensing means controlling the effective driving speed of said drive means for increasing said effective driving speed when said one feed screw has moved upwardly a predetermined amount corresponding to a preselected size of said gaps.

Claim 19

An accurate mechanically variable high reactive power inductor for testing large capacitance loads, such as high-voltage electrical power transmission cables, large capacitors, groups of capacitors, and the like, in a resonance circuit effectively including the capacitance of the load and the inductance of the inductor, comprising a high strength rigid frame, upper and lower magnetic core segments mounted in the frame, said core segments being U-shaped and being positioned with the ends of their legs in opposed relationship defining a pair of gaps therebetween, said upper core segment being vertically movable to vary the size of said gaps, a pair of electrical windings surrounding the respective legs of said core segments and the variable gaps to provide a variable inductance which is varied by changing said variable gaps, a pair of clamping elements extending along opposite sides of said upper core segment for ripping said upper core segment, a pair of heavy crossmembers extending across said upper core segment and extending outwardly beyond opposite sides thereof, said heavy crossmembers being secured to said clamping elements, a nonrotating feed screw secured to the outer end of each of said crossmembers and extending upwardly therefrom, low-friction feed members interposed between the respective feed screws and the upper portion of the frame and operatively engaging the feed screws to produce vertical movement of the feed screws and the upper core segment upon rotation of the feed members to control the gap size between the legs of the upper and lower core segments, drive means operatively coupled to each of said feed members for producing simultaneous and equal effective rotation thereof, said drive means being changeable in effective driving speed, sensing means mounted upon the upper portion of the frame and responsive to the vertical movement of one of said feed screws, and said sensing means controlling the effective driving speed of said drive means for increasing said effective driving speed when said one feed screw has moved upwardly a predetermined amount corresponding to a preselected size of said gaps.