High energy dissipation harmonic filter reactor
AssigneeBBA Canada Limited
InventorsPatrick E. Burke, Norbert Pewny
Life of this patent
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Abstract
An air core inductor having mounted thereon a band of material of selected characteristics providing only an electromagnetically coupled resistance that reflects back into the windings of the inductor for filtering applications.
Claims22
A device for use in electrical power distribution systems and capable of handling high power levels comprising:
- (a) an air core open ended cylindrical coil unit having a plurality of helical coil windings of insulated conductor each beginning at one end of said unit and ending at an opposite end thereof;
- (b) a multi-arm spider unit, comprising a plurality of arms radiating outwardly from a central hub, located at at least one of said opposite ends of the cylindrical coil unit, said coil windings at said end being connected to selected arms of the spider unit associated therewith;
- (c) an electromagnetically coupled resistance element for said coil comprising a band of resistive material circumscribing a portion of said coil unit and spaced radially therefrom.
- (d) band mounting means retaining said band in fixed spaced relation relative to said coil unit;
- and
- (e) means electrically insulating said band from said coil windings, said resistance element being operative solely by electromagnetic coupling with said coil windings lowering the quality factor Q of said coil unit at a selected frequency, or band of frequencies higher than the power system operating frequency.
A filter arrangement, for a power transmission system having a power system operating frequency, comprising an LC circuit wherein the inductor of said LC circuit is an air core reactor having a resistance element operative solely by direct electromagnetic coupling with coil windings of said reactor for lowering the quality factor Q of the reactor at a selected frequency or band of frequencies higher than said power system operating frequency, said resistance element conductively insulated from the inductor.
A filter system for an electrical power distribution installation comprising a first parallel connected LC arrangement connected in series with a second serially arranged LC arrangement each of which is of predetermined capacity and wherein the inductor of each LC arrangement is an air core reactor having a resistance element, operative solely by electromagnetic coupling with said reactor, said resistance element being a band of resistance material radially spaced from the inductor associated therewith to dissipate predetermined energy, said coupling being responsive to selected predetermined frequencies lowering the quality factor Q of the reactor at said selected predetermined frequencies.
An electrical filter capable of handling high energy levels comprising:
- (a) an open-ended tubular air core reactor having opposite ends and at least one coil winding beginning at one of said opposite ends and an ending at the other of said opposite ends;
- (b) at least one band of selected resistive material arranged in a closed loop encircling a selected portion of said tubular reactor, each said band having a width in a direction lengthwise of the tubular reactor that is substantially greater than its total thickness which is perpendicular to said lengthwise direction;
- and
- (c) means supporting each said band at a position radially spaced from said reactor and electrically insulated from said windings, each said band of material providing a resistance for the reactor and operative only by direct electromagnetic coupling with each said winding for lowering the quality factor Q of the reactor at a selected frequency, or band of frequencies, higher than a power system frequency of a power distribution system in which it is used.
Apparatus for use in an AC power transmission system comprising:
- an air core reactor unit,
- a resistance for said reactor operative solely by electromagnetic coupling therewith,
- said resistance comprising a metallic element electrically isolated from coil windings of said reactor and positioned in magnetic coupling with said windings, and
- means mounting said metallic element on said reactor in spaced relation therewith for dissipating large quantities of heat from said metallic element without adversely damaging said reactor,
- said metallic element being responsive to electro-magnetic fields generated by coil windings of said reactor by inducing, during use, at a selected frequency or band of frequencies higher than a power frequency of the power transmission system, I.sup.2 R losses that reflect back into said windings causing the quality factor Q of the said reactor to be lowered at said selected higher frequency.
In an air core reactor unit for an electrical power distribution system, the reactor unit having a coil winding therein, the improvement comprising:
- a resistance element for dissipating power and reducing a quality factor Q of said coil winding in a predetermined frequency range greater than a predetermined operating frequency of the power distribution system,
- said resistance element radially spaced apart from said coil winding,
- an insulator for electrically insulating said resistance element from said coil winding,
- said resistance element being electrically connected to said coil winding only inductively by direct electromagnetic coupling of an electromagnetic field generated by said coil winding to said resistance element,
- whereby a current is induced in said resistance element through said electromagnetic coupling to generate I.sup.2 R losses in said resistance element in said predetermined frequency range, said losses being inductively coupled to said coil winding.
Dependencies are inferred from the claim text.