MECHANICALLY VARIABLE HIGH POWER INDUCTOR FOR TESTING CAPACITIVE LOADS SUCH AS HIGH VOLTAGE ELECTRICAL POWER TRANSMISSION CABLES

摘要

1336740 Inductors HIPOTRONICS Inc 23 Dec 1970 [29 Dec 1969] 61250/70 Heading HIT In a large inductor 10 comprising two U- shaped core members 12, 14 and electrical windings 16, the gap 82 between the core members is varied by raising and lowering the upper member 12 using a two-speed drive operating four lead screws 24, 26, 28, 30. The core members are clamped between pairs of iron beams 36 but with insulating sleeves on the clamping bolts 40 and insulating layers of fibreboard between the inside faces of the beams and the laminations. Low friction screw feed assemblies 42 include nut members 44 secured to sprockets 48 which are chain driven from a worm gear 54, the worm 70 being driven through either a low- or high-speed clutch (72, 72SP1/SP) by an electric motor (60, Fig. 4, not shown). A microswitch 90 (Fig. 5) stops the motor when the upper core member and the lead screws are fully raised, a second microswitch 92 slows the drive speed below a predetermined gap size to take account of the non-linear inductance variation with gap size, and a third microswitch 94 stops the motor when the gap has closed and the lead screw drive assembly begins to travel up the screw. Means 81 for adjusting the chain tension is provided, and whole inductor is supported by a rigid steel frame 18 which may be submerged in cooling oil. The inductor in the embodiment is rated at 3000 KVA, has an upper core member weighing 5000 lbs. and may be used when testing large capacitive loads to obtain resonance in the testing circuit.