Non-interruptible power supply systems

A three phase generator capable of generating alternating electrical current of a constant selected frequency and a substantially constant selected voltage, in combination, a support frame, a driving means on the support frame, a rotatable shaft with a hollow cylindrical shell attached thereto and supported by the frame for rotational movement by the driving means, three spaced field cores of high permeability soft magnetic material attached to the inner surface of the cylindrical shell, each field core having a central cylindrical aperture coaxial with the shaft with a layer of permanent magnetic material applied to the surface of the cylindrical aperture, a fourth exciter field core applied to the inner surface of the cylindrical shell, the exciter field core comprising high permeability soft magnetic material having a cylindrical aperture coaxial with the shaft and a layer of permanently magnetized hard magnetic material applied to the surface of the aperture, an elongated member supported by the frame and extending into the shell, four slotted stator cores of a high permeability soft magnetic material and each having an outer cylindrical surface smaller than and matching the cylindrical apertures in the four field cores, the four slotted stator cores being held by the elongated member so that each stator core is aligned in operative juxtaposed position with respect to a field core, the slotted stator core juxtaposed with the exciter field core having exciter windings in the slots for generating A.C. exciter potential when the permanently magnetized exciter field core rotates about it, each of the other three slotted stator cores having a first pair of slots with an excitation coil therein, at least one other pair of slots substantially diametrically opposite to said first pair of slots with a modifying winding therein, a supplementing winding placed in slots at about 60.degree. and about 240.degree. in a clockwise direction from the excitation coil, and potential output windings disposed in each stator, the potential output windings comprising (a) sets of primary windings of which one set is wound in slots on one side of the diameter passing through the excitation coil and the other set is wound in slots on the other side of said diameter, the primary windings in each of the three stator cores producing single phase A.C. potential in operation, and (b) sets of leading windings wound in slots other than said first pair of slots so as to produce single phase A.C. potential that leads the A.C. potential of the primary windings of the same stator by from about 110.degree. to 115.degree., but the single phase potentials of the leading windings being synchronized with the single phase A.C. of another primary winding, the output leads of the primary winding of each stator being connected in series with the output leads of the leading winding of one of the other stators with which it is in synchronism, the combined potential outputs from the three potential output windings comprising three phase A.C. with low total harmonic distortion, electrical control means supplying A.C. derived from the exciter windings and A.C. from the supplementing windings to each excitation coil in such timed relation and of such magnitude that the magnetic field thereof will cause a pattern of magnetic poles to be formed with a high initial remanent magnetic density in each of the layers of permanent magnetic material in the said three spaced field cores juxtaposed to each of the stator cores whereby to generate A.C. of the selected frequency in the potential output windings at an initial voltage, the electrical control means also supplying, in response to the initial voltage of the A.C. in the potential output windings differing from the selected voltage, electrical A.C. to the modifying windings of a magnitude such that a magnetic flux is generated therein that will modify the initial remanent flux density in the previously formed pattern of magnetic poles so that the potential output windings reacting with this modified flux density presented by the pattern of magnetic poles in the rotating field cores will generate an A.C. of a substantially constant desired voltage and a substantially constant frequency.

In a non-interruptible power supply system to furnish A.C. of a substantially constant selected frequency and of a substantially constant voltage, in combination, a motor connected to a first source of electrical current which source is subject to (a) occasional total power interruptions for prolonged periods, (b) brief power interruptions lasting up to several seconds during which the motor will keep rotating due to its inertia, and (c) voltage irregularities including excess and subnormal voltages during which the motor will continue rotating, an independent auxiliary prime mover enabling rotation of the motor in the event of the (a) prolonged total power interruptions, a first control means responsive to a total power interruption from the first source lasting more than a predetermined period of seconds to cause the auxiliary prime mover to begin functioning, to disconnect the motor from the first source after a selected time period elapses and to connect the motor to the auxiliary prime mover to cause the motor to rotate, said first control means also being responsive to resumption of power flow from the first source of electrical current to disconnect the auxiliary prime mover from the motor, to cause the auxiliary prime mover to cease operating and to connect the motor again to the first source, a constant frequency-constant voltage A.C. generator being connected to and driven by the motor, the generator comprising a plurality of rotatable fields and a cooperating stationary wound armature associated with each field, each rotating field comprising a core high permeability soft magnetic material with a cylindrical face having an applied layer of permanent magnetic material thereon, each stationary wound armature comprising a slotted core of high permeability soft magnetic material with a cylindrical surface juxtaposed and operatively aligned with the cylindrical face of an adjacent field, each slotted armature core having an excitation coil in a first pair of adjacent slots and capable of being energized with A.C. to develop a magnetic flux of sufficient strength to produce in the juxtaposed layer of permanent magnet material a pattern of magnetization comprising north and south magnetic poles as it rotates past the excitation coil, potential output generating windings in other slots in each armature to provide for a two pole armature, modifying windings in at least two slots in each armature core at a point substantially diametrically opposite to the said first pair of slots, supplementing windings wound between at least two slots located at about 60.degree. and 240.degree. clockwise of the first two slots, at least one other exciter field core of high permeability soft magnetic material with a cylindrical face having a layer of permanently magnetized permanent magnetic material applied thereto and rotatably driven by the motor, and an associated slotted exciter stator with exciter windings in slots in a cylindrical surface juxtaposed and conforming to the cylindrical face of the exciter field core whereby to generate an exciter A.C. as the exciter field core rotates with respect to the exciter stator, and second electrical control means for receiving the exciter A.C. and supplying therefrom a predetermined A.C. of selected frequency and of a suitable magnitude to the excitation coil in each armature along with electrical current developed in the supplementing winding thereof to enable it to magnetize the layer of permanent magnet material in the juxtaposed field core to assume a desired pattern of magnetization at an initial high remanent flux density, the second electrical control means also comparing the voltage in the potential output windings generated when the thus magnetized field cores rotate with respect to the stators, with a standard voltage and, when they are not substantially the same, supplying sufficient electrical current to the modifying winding to develop a sufficient level of modifying magnetic flux to change the initial remanent flux in the layer of permanent magnetic material to a different remanent flux level such that it will induce the desired standard voltage in the potential output windings.

In a three phase A.C. generator capable of generating A.C. of a substantially constant selected frequency and substantially constant selected voltage, in combination, a driving motor subject to variations in speeds in operation, a shaft rotated by the motor, a cylindrical shell attached to the shaft, three main field cores of soft magnetic material of high magnetic permeability attached to the inside walls of the shell, each main field core having a cylindrical aperture coaxial with the axis of the shaft with a layer of permanent magnetic material of high magnetic memory applied to the cylindrical surface of each aperture, the exposed surface of the layer of magnetic material being coaxial and cylindrical, a fourth exciter field core of soft magnetic material of high permeability also attached to the inside walls of the cylindrical shell and having a cylindrical aperture therein with a layer of hard magnetic material permanently magnetized into a series of poles, lining the surface of the aperture and having an expose cylindrical surface coaxial with the shaft, a frame supporting the motor, the shaft and shell for rotation thereon, a fixed support member on the frame having a portion extending into the cylindrical shell and projecting into the cylindrical apertures of the field cores, three slotted main stators with cylindrical outer surfaces carried by the fixed support member and positioned with a cylindrical outer surface of each stator operatively juxtaposed with respect to the cylindrical aperture and the layer of magnetic material of each main field core, the slotted stators comprising soft magnetic material of high permeability, each stator having a first pair of adjacent slots with an excitation coil therein, a second pair of slots at a point diametrically opposite the first pair of slots with a modifying winding therein, complementing windings wound in slots at 60.degree. and 240.degree. clockwise from the first pair of slots, and potential output windings in the remaining slots in each stator core to provide for a two pole armature, a fourth slotted excitor stator carried by the fixed support member and having a cylindrical surface in juxtaposition with the cylindrical surface of the exciter field core having the layer hard magnetic material permanently magnetized into a selected pattern of north and south magnetic poles, an exciting winding in the slots of the exciter stator which will generate an exciting A.C. when the exciter field core is rotated with respect thereto, electrical control means for directing the flow of a desired frequency A.C. derived from the exciter A.C. to the excitation coils in each of the three main stators, and the A.C. electrical output of the supplementing windings also being applied to the excitation coil by means of a resonant circuit therewith, the total A.C. supplied to the excitation coils being of such a magnitude that each of the excitation coils will cause the layer of permanent magnet material in the immediately juxtaposed main field core to assume a desired pattern of magnetization at a high initial remanent flux density, the potential output windings when reacting with the magnetic field of the so magnetized layer in each stator generating single phase A.C. of the same frequency as the A.C. supplied to the excitation coil, the voltage of the potential output windings being compared by the electrical control means with a desired standard voltage and any difference causing the electrical control means to supply a controlled A.C. to the modifying windings to set up a magnetic flux sufficient to modify the initial remanent flux density of the pattern of magnetization of the layer of permanent magnet material in the juxtaposed field core to a level that will induce in the potential output windings of each stator an A.C. of the desired voltage.

In a control system for controlling the output of an A.C. generator having at least one field core of soft magnetic material with a cylindrical surface carrying a layer of permanent magnetic material thereon, a cooperatively juxtaposed wound slotted armature rotatable with respect to the field core, the armature being of soft magnetic material having at least two slots with an excitation coil therein, other slots with a modifying winding therein, and other slots with primary windings for generating an A.C. potential when the armature and field core rotate with respect to each other, the control system comprising transformer means having a primary winding supplied with relatively high frequency A.C. and secondary windings supplying high frequency A.C. to a plurality of controllably energizable semiconductor devices connected in a circuit with means supplying precisely timed control pulses thereto, the controllable semiconductor devices effecting full wave rectification of the high frequency A.C. to produce successive precisely timed half cycle positive and negative pulses of lower frequency A.C., each pulse thereof comprising a plurality of fully rectified half waves of the high frequency A.C., the lower frequency A.C. so produced being conducted to a resonant circuit comprising the excitation coil, an inductance and a capacitor, the lower frequency A.C. flowing through the excitation coil producing timed pulses of successive north and south pole magnetic flux that magnetize the layer of permanent magnetic material as it rotates past the excitation coil to a pattern of north and south magnetic poles with an initial remanent flux density, the rotation of the so-patterned magnetic layer with respect to the primary windings in the armature generating an A.C. potential of a frequency substantially identical with the frequency of the A.C. applied to the excitation coil, means for comparing the A.C. generated in the primary windings with a selected potential, and means responsive to any difference in potential operative to convey a porportional amount of timed lower frequency A.C., from the output of the semiconductor devices to the modifying windings, to develop therein pulses of magnetic flux sufficient to change the initial remanent flux density in the magnetic pattern present in the layer of permanent magnetic material, to a new remanent flux density, such that the primary windings will generate substantially the selected potential.

In an A.C. electrical generator capable of generating A.C. of a substantially constant selected frequency and a substantially constant selected voltage, having a first support means carrying at least one power field core and an exciter field core, the power field core and the exciter field core each comprising a body of high permeability soft magnetic material and having a circular surface with an applied layer of magnetizable permanent magnetic material thereon, the applied layer of permanent magnetic material on the exciter field core being magnetized to a pattern of north and south magnetic poles, a second support means carrying slotted and wound armature cores equal to the number of the field cores and each being juxtaposed and operatively aligned with a field core, each armature comprising a body of high permeability soft magnetic material with a circular surface close to and concentric with the circular surface of its juxtaposed field core, means for rotating one of the support means with respect to the other whereby the wound armature juxtaposed with respect to the exciter field core will generate an A.C. potential as the magnetized layer with north and south magnetic poles moves with respect to it, the improvement comprising providing a plurality of windings in each juxtaposed with a power field core wherein the plurality of windings comprises:

• (a) an excitation coil energizable with A.C. in a first pair of slots, the excitation coil producing a pattern of north and south magnetic poles in the layer of permanent magnetic material in the juxtaposed power field core as it rotates,
• (b) a supplementing winding in selected other slots for generating an A.C. as the so-magnetized layer moves with respect to the armature, A.C. so generated is supplied to the excitation coil, and
• (c) power output windings in other slots for generating A.C. potential as the magnetized field core rotates with respect to the armature,
• and electrical control means to supply the excitation coil with A.C. derived from the A.C. from the exciter armature combined with the A.C. from the supplementing winding to enable the excitation coil to produce a sufficiently strong magnetic field to cause the layer of permanent magnetic material juxtaposed with it to form a desired pattern of north and south magnetic poles at a desired level of magnetic remanence whereby to enable the power output windings to generate A.C. potentials of the selected constant frequency and the selected constant voltage.