The present invention relates to a device which is capable of controlling magnetic action, and an electric generator including the same, and more particularly, to an electric generator which may control magnetic action between a rotor and an armature of the electric generator in response to a fluctuation in the motive power supplied to a rotor shaft and a fluctuation in the load of electricity induced from the electric generator, thus to compensate for such fluctuations with voltage variation, and induce constant electricity by frequency, and parts for the same.
An electric generator is a device configured to convert mechanical and thermal energy into electrical energy. In general, the electric generator includes a rotor shaft for receiving a rotational force from a prime mover; an electric generator case in which parts of the electric generator are installed to protect the same; a rotor installed about the rotor shaft and including permanent magnets or field windings for generating a magnetic field; an exciter for supplying electricity to the field windings; an armature (i.e., stator) magnetized by the magnetic field generated from the permanent magnets of the rotor and including windings for linking the same; bearings for rotatably supporting both end portions of the rotor shaft; a lubrication device for supplying lubricant to the bearings; a ventilation and cooling device for removing heat generated from the electric generator and the like.
In the electric generator, as the rotor shall that receives mechanical rotational energy rotates together with the rotor in which unipolar, non-polar (slot portion) and other polarities are partitioned on an outer circumference thereof by interlocking with the rotation of the rotor shaft, alternating magnetic action occurs on the armature that surrounds the outer circumference of the rotor by an inner circumference thereof with a gap therebetween. Electromagnetic waves are generated in the windings buried in an armature magnetic iron core by the alternating magnetic flux formed in the armature magnetic iron core due to electromagnetic interaction. The waves are alternately induced in the windings, and frequency and voltage of the alternating current electricity are determined by an alternating cycle of the rotor.
A fluctuation in the motive power generating mechanical energy and a fluctuation in the electric load directly affect an operation of the electric generator. Operation speed and output of the electric generator primarily depend on the operation of the prime mover that provides the motive power to the electric generator. In addition, a fluctuation in the load using electricity generated from the electric generator also directly affects the operation of the electric generator.
According to the theory of electromagnetism, when an electric current flows through a rotating conductor, the Lorentz force naturally occurs, which acts in a direction opposite to the rotational direction. Accordingly, as the the rotor of the electric generator rapidly rotates in order to induce electricity with a high frequency and voltage, the Lorentz force that obstructs the rotation of the electric generator is increased in proportion thereto.
Thereby, the output of the electric generator is increased or decreased depending on a change in the motive power. On the other hand, the Lorentz force that obstructs the operation of the electric generator is proportionally increased or decreased depending on the fluctuation in the load using the electricity generated from the electric generator. That is, if a magnitude of the motive power supplied to the electric generator is changed the Lorentz force that obstructs the rotation of the electric generator is also increased or decreased in proportion thereto. The increase or decrease in the Lorentz force and the magnitude of the power induced by the electric generator are relative to each other, and the magnitude of the motive power, the load and the Lorentz force are closely related to the change in the rotation speed of the rotor shaft.
Thereby, in order to induce more electricity from the electric generator, grater mechanical energy should be supplied from the prime mover to the electric generator to cancel the Lorentz force that obstructs the rotation of the rotor shaft.
Accordingly, when the rotation speed of the motive power supplied to the electric generator is changed or the magnitude of the load using the electricity generated from the electric generator is changed, the rotor frequency and the armature frequency of the electric generator are changed, such that unstable magnetic action occurs between the rotor and the armature, and thereby electricity with unstable voltage and frequency is induced from the electric generator. In particular, when using wind energy with a large change in a wind speed as the motive power, if the wind speed is weak, the permanent magnets attached to the rotor strongly attract the core of the stator, and the rotor does not rotate at all or rotates weakly due to the brake phenomenon. Thereby, when weak wind below a certain wind speed blows, that is, the motive power provided for power generation is decreased to a predetermined magnitude or less, power generation is completely stopped.
For this reason, in order to supply stable electricity to a power system or an electricity consumer, electricity with irregular frequency and unstable voltage should be treated to a current having the rated frequency and rated voltage through a frequency converter and a transformer. In particular, it is easy to control the voltage, but the frequency conversion process requires high equipment costs and is complex, as well as a large amount of energy is wasted during the rectification process.
In consideration of the above-described problems, Korean Patent Registration Publication No. 10-1136817 proposes a permanent magnet generator having a moving type rotor.
In the above prior art, the generator is configured in such a way that, as the rotor moves in an axial direction according to the rotational force of the rotor shaft, parallel planes of the permanent magnet of the rotor and the armature core facing the same vary. When the rotational force is reduced, the rotor is moved so that only a portion of each of the permanent magnet and the armature core face each other, thereby controlling so that the brake action due to the attractive force of the permanent magnet of the rotor can be minimized. Therefore, since the rotor can be rotated to generate electricity even with an external force equal to or less than a certain rotational force, power generation efficiency is improved.
However, the above prior art with the above-described advantages has various disadvantages in terms of the structure. When considering a moving distance of the rotor to control the magnetic action from the maximum to the minimum (a minimum condition for the magnetic action is a state in which the rotor and armature core are shifted as much as possible, and they only partially correspond to each other at the end), the length of the electric generator should be increased to almost several times or more, such that the size of the device is increased. In addition, it is unreasonable to configure the rotor that should be rotated with being fixed to the shaft so as to be able to slide in the axial direction and move the rotor by adopting a spline key structure to the shaft, and maintenance may be difficult. In particular, there is plenty of room for vibration and friction which will be generated due to weight bias. In addition, since a pneumatic cylinder is used as a means for moving the rotor, it is difficult to precisely move the rotating rotor to a correct position in a lateral direction.
As another problem, not only a centrifugal force acts on the rotating rotor, but also a mutual attraction with the armature acts thereon, such that the movement of the rotor in the lateral direction is not preferable. When supplying lubricant to the spline, the armature is contaminated by the supplied lubricant, and fires may occur. As foreign matters are trapped between the gaps, various problems such as ignition due to heat generation and a reduction in the efficiency of magnetic action may occur.
In addition, it is difficult to apply the conventional electric generator to a large-capacity electric generator, and moreover, it is technically difficult to move the rotor with being rotated at a high speed. Further, it is more difficult to apply the conventional electric generator to a high-speed rotor type electric generator, because a service life of the device is significantly reduced due to the induced noise and vibration.
(Patent Document 1) Korean Patent Registration Publication No. 10-1136817
Accordingly, in consideration of the above-mentioned circumstances, it is an object of the present invention to provide an electric generator which allows the magnitude of mutual magnetic action between a rotor and an armature to be self-adjusted in the electric generator against a fluctuation in a motive power or a fluctuation in an electric load, such that the magnitude of an induced electromotive force is controlled to compensate, with voltage variation, for amounts of the fluctuation in the motive power and the fluctuation in the electric load and to induce electricity with a uniform frequency from the electric generator, while stabilizing the prime mover or load devices, and parts optimized for the same.
Accordingly, the electric generator of the present invention not only performs functions such as an efficient governor and a productive braking device for controlling an operation of the prime mover, but also has utility capable of appropriately taking measures against outlet reactance due to an increase or decrease in the electric load.
Another object of the present invention is to provide an electric generator which has a compact size, high energy conversion, energy saving and efficiency, is easy to manage, and contributes to stably maintaining a power supply and demand system, and parts optimized for the same,
To achieve the above objects, according to an invention of claim 1, there is provided a magnetic iron piece used in a rotor of an electric generator, the magnetic iron piece for a rotor including: a body having a U-shaped cross section and extending in a. longitudinal direction, wherein both side walls of the body facing each other have protrusions and recesses of a concave-convex structure formed at upper ends thereof in a square shape, and the protrusions of the concave-convex structure form rotor magnetic poles, and the recesses form rotor non-magnetic sections, such that the rotor magnetic poles and the rotor non-magnetic sections are alternately and repeatedly provided.
According to an invention of claim 2, first permanent magnets of a first permanent magnet set may be inserted into first slots concavely formed inside the U-shaped of the magnetic iron piece, the rotor magnetic poles and the rotor non-magnetic sections may accommodate the first permanent magnets installed therein with a size corresponding to heights thereof, and the first permanent magnets may be arranged so that their N and S poles are expressed by contacting each of inner wall surfaces on both sides of the magnetic iron piece, and all polarities of the N and S poles face the same direction.
According to an invention of claim 3, the upper end of the rotor magnetic pole, which is the protrusion, may include magnetic pole concentration parts (head parts) having jaws protruding beyond a wall thickness of the magnetic iron piece, and the first permanent magnets disposed in the rotor magnetic pole may be installed to be caught and supported by the jaws of the magnetic pole concentration parts.
According to an invention of claim 4, there is provided a rotor mounted on a rotor shaft of an electric generator, the rotor for an electric generator including: a rotor frame fixed to the rotor shaft so as to rotate together with the rotor shaft; a plurality of first grooves formed at a predetermined interval over an entire circumference of the rotor frame and extending in an axial direction; and a rotor magnetic iron piece according to claim 2 in which a portion of an each lower end of a U-shaped body is inserted and mounted in the first grooves, wherein second slots are formed in the gap between the rotor magnetic iron pieces, and second permanent magnets of a second permanent magnet set are inserted in the second slots in the same size and manner as the first permanent magnet set, and the second permanent magnets are arranged so as to have the same polarity as that of the first permanent magnets with a wall surface of the rotor magnetic iron piece interposed therebetween.
According to an invention of claim 5, the rotor frame may be formed of an assembly of a plurality of divided unit bodies, and protective covers may be fastened to both sides of the assembly by bolts.
According to an invention of claim 6, the plurality of divided unit bodies may be coupled to each contact surface thereof through concave and convex coupling parts having a circular or polygonal shape corresponding to each other in a male and female coupling manner.
According to an invention of claim 7, there is provided a magnetic iron piece used for an armature of an electric generator, the magnetic iron piece for an armature including: wherein both side walls of the body facing each other have protrusions and recesses of a concave-convex structure formed at upper ends thereof in a square shape, and the protrusions of the concave-convex structure form armature magnetic poles, and the recesses form armature non-magnetic sections, such that the armature magnetic poles and the armature non-magnetic sections are alternately and repeatedly provided, and after each bobbin is fitted to both side walls forming the U-shaped cross section, coils are wound around the bobbin to form armature windings.
According to an invention of claim 8, there is provided an armature installed so as to surround an outer circumference of a rotor mounted on a rotor shaft of an electric generator with a gap therebetween, the armature for an electric generator including: an armature frame manufactured in a non-magnetic hollow cylindrical shape and installed so as to surround the outer circumference of the rotor; a plurality of second grooves formed in an inner circumference of the armature frame at a predetermined interval over an entire circumference thereof and extending in the axial direction; and an armature magnetic iron piece according to claim 7 in which a portion of an each lower end of a U-shaped body is inserted and mounted in the second grooves.
According to an invention of claim 9, the armature frame may be formed of a single cylindrical body or an assembly of a plurality of divided ring-shaped bodies, LM guide rails may be installed in a plurality of portions on an outer circumference of the armature frame to have a predetermined phase angle in an axial direction, the LM guide rails may be configured to guide a linear movement in the axial direction along the guide of LM guide bearings provided on an inner surface of an electric generator case, and prevent rotation of the armature frame in a circumferential direction, and the LM guide rails may be used as a fastening means of the plurality of divided ring-shaped bodies.
According to an invention of claim 10, a space between the armature windings of the armature magnetic iron piece may be insulated.
According to an invention of claim 11, side frame members may be fastened to both opened sides of the cylindrical armature frame by bolts, and sleeves for rotatably supporting the rotor shaft may be provided at centers of the side frame members, and the sleeves may be mounted to slide along the rotor shaft within a predetermined distance range.
According to an invention of claim 12, there is provided an electric generator including: a rotor shaft connected to the rotor shaft of a power source by a clutch coupling; a rotor for an electric generator according to any one of claims 4 to 6, which is mounted on the rotor shaft to be rotatable together therewith; and an armature for an electric generator according to any one of claims 8 to 10 which is installed concentrically so as to surround an outer circumference of the rotor of an electric generator predetermined gap therebetween, is installed to allow movement within a predetermined interval range in an axial direction of the rotor, and has protrusions and recesses of a concave-convex structure having the same length as the protrusions and recesses of a concave-convex structure of the rotor corresponding thereto; an electric generator case which surrounds an outer circumference of the armature for an electric generator to protect the same; a linear motor configured to move the rotor through a mechanism capable of being advanced or retracted in the axial direction; a speed sensor configured to detect a rotation speed of the rotor shaft or a power meter configured to measure output voltage and frequency of the electric generator; and a controller configured to control and drive the linear motor based on information detected from the speed sensor or the power meter, wherein the controller controls the linear motor so that the armature is moved to a first position in a direction in which a corresponding length between an armature magnetic pole tip and a rotor magnetic pole tip is decreased at the beginning of driving the electric generator or when a driving speed of a prime mover is decreased, and conversely, controls the linear motor so that the armature is moved to a third position in a direction in which the corresponding length between the armature magnetic pole tip and the rotor magnetic pole tip is increased when the driving speed of the prime mover is increased.
According to an invention of claim 13, side frame members may be fastened to both opened sides of the cylindrical armature frame of the armature by bolts, and sleeves (bearing housing) for rotatably supporting the rotor shaft may be provided at centers of the side frame members, and the sleeves may be mounted to slide along the rotor shaft within a predetermined distance range.
According to an invention of claim 14, a movement distance of the armature in the axial direction may correspond to a width of a protrusion or a width of a recess of the armature magnetic iron piece.
According to an invention of claim 15, the controller may control the movement distance of the armature in the axial direction based on rotation speed information detected by the speed sensor or output voltage and frequency information of the electric generator detected by the power meter.
According to an invention of claim 16, the upper end of the rotor magnetic pole, which is the protrusion of the rotor magnetic iron piece, may include magnetic pole concentration parts (head parts) having jaws protruding beyond a wall thickness of the magnetic iron piece, and first permanent magnets of a first permanent magnet set and second permanent magnets of a second permanent magnet set, which are respectively disposed in the first slots and the second slots, may be installed to be caught and supported by the jaws of the magnetic pole concentration parts with being in contact with the rotor magnetic pole.
According to an invention of claim 17, in the armature and the rotor, the recess forming the non-magnetic section may have a length formed longer than the length of the protrusion forming the magnetic pole.
According to an invention of claim 18, the power source driving the electric generator may be any one of wind energy, hydraulic energy, thermal energy, engine driving power, and steam energy.
According to an invention of claim 19, the first permanent magnets of the first permanent magnet set buried in the first slots of the rotor magnetic iron piece may be installed vertically in a protrusion section and horizontally in a recess section, may be formed to match the protrusion and the recess of the square concave-convex structure formed on the upper portion of the magnetic iron core forming wall members on both sides, and may be fixed in close contact by a metal adhesive so that the same poles face the magnetic iron core.
According to an invention of claim 20, a center guide provided in the bearing housing of an end shield may be formed in a polygonal shape, and polygonal sleeves or linear bearings may be installed at centers of the side frames installed at both ends of the armature, thereby supporting the armature so as to be linearly reciprocated.
According to an invention of claim 21, the groove of the armature frame on which the LM guide rails may be mounted is configured to form an exhaust passage in the axial direction.
According to an invention of claim 22, exhaust passages extending in the axial direction may be formed on an outer surface of the armature frame between the plurality of LM guide rails.
Since the electric generator of the present invention employs a device for controlling the magnetic action, a fluctuation in the output of the prime mover and a fluctuation in the electric load are compensated by an increase or decrease in voltage through the adjustment of the magnetic action, and electricity with a prescribed frequency may be induced. Accordingly, it is possible to induce electricity with the prescribed frequency from an induction electric generator without an excitation system, and the electric generator may perform the same role as a braking device for controlling the prime mover and a governor for efficiently managing the operation of the prime mover, as well as it is possible to play a role in effectively coping with the fluctuation in the electric load. Accordingly, there is provided an electric generator having high energy conversion efficiency, high energy efficiency of a prime mover and an electric system, and is capable of saving energy. Specifically, the following effects are expected in the electric generator of the present invention.
Hereinafter, configurations of the present invention will be described with reference to the accompanying drawings.
An electric generator 10 of the present invention has a hollow cylindrical electric generator case 11 in which parts are mounted to protect the same. The electric generator case 11 includes corrugations formed on an outer side for cooling, and covers 11a and 11b which cover both sides thereof to form a part of the case 11 so as to protect the internal parts, and these covers are fastened to both sides of the case body by using a fastening means such as bolts.
In addition, a rotor 12 and an armature 13 are installed in the case 11. The rotor 12 includes a rotor shaft 14 at a center thereof. Herein, the rotor 12 is coupled to the rotor shaft 14 by a key, and is configured to rotate together with the rotor shaft 14. One end of the rotor shaft 14 extending outward through the cover 11a is connected to a shaft 15a of a prime mover 15, which is a power source, via a clutch coupling 15b. Therefore, the electric generator is configured to receive a rotational driving force of the prime mover 15 through the shaft 15a and the rotor shaft 14, and convert mechanical energy into electrical energy.
The rotor shaft 14 is rotatably supported by bearings 16 and 16a provided in bearing housings 17 and 17a, and the covers 11a and 11b for protecting the bearing housings 17a are fixed to the both opened sides of the electric generator case 11 with bolts. The armature 13 is installed on an inner circumference of the electric generator case 11 so as to surround an outer circumference of the rotor 12. The electric generator case 11 is formed in a size having a predetermined clearance 18 (movement allowable space L1 of the armature) so that the armature 13 installed therein can linearly reciprocate within a predetermined distance L1 in an axial direction.
In addition, linear motion bearings for guiding an axial movement of the armature 13, that is, linear motion (LM) guide mechanisms 19: 19a and 19b, are formed on the inner circumference of the electric generator case 11 and the outer circumference of the armature 13 in multiple rows in a direction parallel to the rotor shaft 14. Therefore, the LM guide mechanism 19 helps the armature 13 to smoothly reciprocate and linearly move in the axial direction within the predetermined clearance 18 (L1) inside the electric generator case 11. Accordingly, the armature 13 is configured in such a way that rotation in a circumferential direction is prevented, and movement in the axial direction within the predetermined clearance 18 (L1) is allowed, thus to allow a relative position with the rotor 12 to be changed.
Although not shown in the drawings to avoid complexity, an oil supply device is provided on one side of each of the covers 11a and 11b for lubrication and cooling of the bearings 16. The electric generator case 11 has exhaust ports formed on one side thereof for discharging the heated air to an outside to cool the internal parts when an internal temperature is increased. Support members 20 are installed at lower end portions of the electric generator case 11, and the support members 20 are preferably formed as levelers so as to prevent vibration and adjust a level, if possible. In addition, optionally, a flywheel for imparting an inertial force to the rotor 12 and a fan for cooling heat dissipated from the electric generator in contact with the flywheel may be mounted between the outside of the electric generator case 11 and the clutch coupling 15b.
As such, the rotor magnetic iron piece 23 extending in the radial direction perpendicular to the rotor shaft has rotor magnetic poles 25 as protrusions and rotor non-magnetic sections 26 as recesses, which are alternately formed at upper ends on both sides that define the first slots 27 in the axial direction in a form of the rectangular concave-convex structure. The rotor non-magnetic sections 26 are formed by cutting and removing the material on the upper portions of the magnetic iron piece by press punching at a predetermined interval. In addition, a first permanent magnet set 29 having a plurality of first permanent magnets shown in
The first permanent magnet set 29 includes first permanent magnets which have a shape close to a substantially rectangular parallelepiped shape buried in the first slots 27 of the rotor magnetic iron piece 23 (however, the shape, size, and height of the magnet are manufactured to depend on the shape of an inner surface of the first slot), and are arranged with the same pole facing the same direction (hereinafter, the first permanent magnet set referring to the entire first permanent magnet is denoted by a representative reference numeral 29, the first permanent magnets installed in the rotor magnetic poles as the protrusions are denoted by a reference numeral 29a, and the first permanent magnets installed in the rotor non-magnetic sections as the recesses are denoted by a reference numeral 29b). For example, the first permanent magnets 29a are installed in the rotor magnetic poles 25, which are the protrusions, aligned with heights of the head parts 28, and the first permanent magnets 29b are installed in the rotor non-magnetic sections 26, which are the recesses, aligned with heights of upper portions of wall surfaces 26a and 26b, such that they are buried close to the inner surface of the rotor magnetic iron piece 23. At this time, as shown in
Meanwhile, the second permanent magnet set 31 includes second permanent magnets which are buried in the second slots 30 formed between the adjacent rotor magnetic iron pieces 23 by continuously installing in the circumferential direction at a predetermined interval t1 from each other in the same shape, size, and arrangement method as those of the first permanent magnet set 29 (hereinafter, the second permanent magnet set referring to the entire second permanent magnet is denoted by a representative reference numeral 31, and high second permanent magnets vertically installed in the second slots in contact with the rotor magnetic poles as the protrusions are denoted by a reference numeral 31a, and low second permanent magnets installed horizontally in contact with the rotor non-magnetic sections as the recesses are denoted by a reference numeral 31b, wherein the size and shape thereof depend on those of the second slots). The first permanent magnet set 29 buried in the first slot 27 and the second permanent magnet set 31 buried in the second slot 30 are disposed so that the same polarities correspond to each other with the wall surface of the rotor magnetic iron piece 23 interposed therebetween. For example, if the polarity of the first permanent magnets 29a and 29b of the first permanent magnet set 29 in contact with the other side wall surfaces 25b and 26b of the magnetic iron piece is S pole, the polarity of the second permanent magnets 31a and 31b of the second permanent magnet set 31 in contact with the other side wall surfaces 25b and 26b is S pole (or otherwise N pole, if the polarity is N pole), so that the first and second permanent magnets are arranged with the same polarity in contact with each other. In addition, the first permanent magnet set 29 is installed vertically in the rotor magnetic poles 25, and the second permanent magnet set 31 is installed horizontally in the rotor non-magnetic sections 26, and then firmly and closely adhered to each other using a metal adhesive. Further, after the first permanent magnet set and the second permanent magnet set are buried and fixed in the first and second slots, respectively, it is necessary to suppress oxidation by preventing moisture and foreign matters from contacting, and to prevent a loss due to friction and heat generation. For this reason, it is preferable to coat these permanent magnets with a non-conductive metal or synthetic resin material having corrosion resistance and abrasion resistance.
When the permanent magnets are arranged and installed in the method as described above, a strong S-polar magnetic field is concentrated and projected through the upper end portions of the wall surfaces of the iron piece in contact with the same polarities of the N and N poles, particularly the head parts 28a having a function to increase concentration, and a strong N-polar magnetic field is concentrated and projected through the upper end portions of the wall surfaces of the iron piece in contact with the same polarity of the S and S poles, particularly the head parts 28b having a function to increase concentration. Thus, compared to the case where only a conventional single polarity is projected, a magnetic field which is almost twice as large is projected through each of the head parts 28a and 28b. As a result, both the S pole and the N pole may be used due to the arrangement structure of the rotor magnetic iron piece 23 and the first and second permanent magnet sets 29 and 31, such that availability of the magnets is high and a separate shielding structure is not required due to the structure. Therefore, a volume of the rotor 12 may be greatly reduced.
Accordingly, the rotor magnetic iron piece 23, the first slot 27, the second slot 30, and the first and second permanent magnet sets 29 and 31 form a rotor yoke. At this time, the circumferential ring-shaped assemblies of the plurality of rotor magnetic poles 25, which are protrusions, form a rotor magnetic pole tip 32, and the ring-shaped assemblies of the rotor non-magnetic sections 26, which are recesses, form a rotor non-magnetic portion 33. As a result, the rotor magnetic pole tip 32 and the rotor non-magnetic portion 33 alternately arranged in a ring shape have a difference in outer diameter in the axial direction. However, when employing an electromagnet rotor rather than the permanent magnet, the magnetic pole tip and the non-magnetic portion may be formed by winding field windings around a plurality of rotor magnetic poles 25 which are protrusions.
An armature frame 34 is made of a non-magnetic material in a hollow cylindrical shape, is accommodated on the inner circumference of the electric generator case 11, and is installed to surround the outer circumference of the rotor 12. The armature frame 34 may be formed as a single hollow cylindrical body. However, as shown in the drawings, it is preferable to form a single cylindrical body by fabricating and assembling a plurality of divided ring-shaped bodies 34a to 34j (representative reference numeral is denoted by 34) for the convenience of processing. As such, when the armature frame 34 is fabricated and assembled with divided ring-shaped bodies 34a to 34j, air circulation passages for discharging heat generated inside the armature 13 to the outside are formed on contact interfaces with each other, or it is easy to implement an internal structure having a complex curvature in the divided ring-shaped body, and thus there is an advantage in that it is easy to manufacture.
As shown in the cross-sectional view of
When the electric generator is operated, heat is generated due to friction with air according to high-speed rotation of the rotor, current generation of rotor field windings, and linkage of armature windings corresponding thereto, etc. Therefore, for cooling, exhaust passages 37a are formed in the inner circumference of the electric generator case on both sides in a direction parallel to the shaft, in which the LM guide rails 19a are provided, and communicate with an exhaust port provided on the side of the electric generator case, thereby performing a heat dissipation function. In addition, a clearance exists in a groove portion in which the LM guide rail 19a is mounted, and the clearance forms an exhaust passage 37b in the axial direction, thereby performing a similar heat dissipation function.
As shown in
In the armature magnetic iron piece 38 shown in
In the cross-sectional shape of the armature magnetic iron piece and the armature shown in
As such, when n armature magnetic iron pieces are arranged on the inner circumference of the armature frame, armature windings are provided in n*2 magnetic iron cores placed on both sides of each of the n magnetic iron pieces. Therefore, n*2 multi-pole multi-phases are formed in the armature, which are connected as an overlapping winding, wave winding, open type winding, closed type winding, annular winding, and high phase winding, etc., thereby leading them to an output terminal.
In addition, in order to prevent the armature winding 42 from being cut or damaged due to a linear reciprocating movement of the armature 13, it is preferable to provide an extra winding in a form of a spring at an end portion of the armature winding.
As shown in
As shown in
In order to set a speed at which the rotor shaft 14 should rotate, set a frequency to be induced from the armature 13, and share information between the prime mover and the load control system, the controller 49 includes a control panel (not shown). A storage battery 50 is mounted in the electric generator case 11 or provided near the electric generator so that the speed sensor 48, the controller 49, and the linear motor 46 are supplied with direct current power and may be used as a load device that increases or decreases the magnitude of the Lorentz force. In addition, the power generation system includes an inverter 51 for converting AC electricity induced from the electric generator 10 into DC in order to store the electricity in the storage battery 50.
According to the power generation system including the electric generator of the present invention, the rotor shaft 14 is connected to the shaft 15a of the prime mover 15 through the clutch coupling 15b to obtain rotational power from the prime mover 15, AC electricity is induced at the armature windings 42 of the armature 13 by the rotation of the rotor 12 and the generated AC electricity is output through the output terminal provided in the electric generator case 11. The electricity output as described above is supplied to the electricity customer after the voltage is regulated at a constant level through an automatic voltage regulator 52. At this time, in order to be able to increase or decrease the Lorentz force when the power supplied from the prime mover 15 to the rotor shall 14 is excessively large, or the load of the electric device using the electrical enemy converted by the electric generator 10 is sharply reduced, the electric generator system may have a separate load device, and includes a load control system for controlling a system connection that receives information from the controller 49 in order to perform a co-operation with the electric generator 10 or the load of the electricity consumer.
Hereinafter, an operation process of the electric generator 10 according to the present invention will be described in detail with reference to
When power generation starts, first, in a state in which the shaft 15a of the prime mover and the rotor shaft 14 are connected to each other by a clutch coupling 15b provided in these shafts, the prime mover 15 (this prime mover may be an engine, a wind power generation unit, or other hydropower generation units, etc.) is driven, and as the prime mover 15 is driven, the rotor shaft 14, which has received the rotational power, rotates.
However, at the beginning of power generation when the prime mover 15 starts to drive, it takes time until the electric generator 10 is normally operated due to the stopping inertial force. In addition, excessive force is applied at the early stage of power generation, such that an excessive overload is applied to the prime mover and electric generator system. At the initial stage of power generation, the rotation speed of the rotor shaft 14 is low, such that the controller 49 controls the linear motor 46 in advance to move the armature 13 in the axial direction to a position shown in
As such, when the magnetic pole tip of the armature and the non-magnetic portion of the rotor (like the non-magnetic portion of the armature and the magnetic pole tip of the rotor) are positioned to face each other, the electromagnetic action interacting between the two tips is minimized. Therefore, when the prime mover 15 is driven, an operation is started in a driving state in which the load of the electric generator is minimal, that is, almost no load. Accordingly, an excessive overload is not applied to the prime mover 15 at the beginning of the start, such that the rotation speed is rapidly increased to reach the rated rotation speed. When the rotation speed of the prime mover 15 is gradually increased, the controller 49 controls so as to move the armature 13 in a direction in which an overlapping amount of the armature magnetic pole tip 43 and the rotor magnetic pole tip 32 is increased in proportion to the increased rotation speed (the armature is moved from the state of
As such, when the rotation speed of the rotor shaft 14 is lower than a prescribed rotation speed, the armature 13 is moved to reduce the magnetic action range, thereby reducing the load applied to the driven prime mover 15. Accordingly, the operating state of prime mover 15 may quickly and smoothly enter the prescribed rotation speed. During the initial operation of the prime mover connected to the electric generator, in accordance with the command of the controller 49 based on the information detected by the speed sensor 48, it is controlled so that the armature 13 of the electric generator 10 is automatically moved to the first position where the magnetic action range is minimum (see
As such, at the time of normal operation conditions in which the prime mover 15 and the electric generator 10 are normally operated under the design load, as shown in
When the rotor 12 rotates in the states shown in
Conversely, when the detected rotation speed is increased, the controller 49 drives the linear motor 46 and controls so as to move the armature 13 in a direction in which the magnetic action range is increased, that is, in a direction in which the corresponding length of the armature magnetic pole tip 43 and the rotor magnetic pole tip 32 is increased (that is, by controlling so as to move the armature from the first position or the second position to the third position), such that the load applied to the operation of the prime mover and the electric generator may be increased to output a greater amount of electricity.
According to the control system of the present invention, the rotor and the armature are constantly linked only when the rotor shaft rotates at a constant speed, such that electricity with a constant frequency may be induced from the electric generator. For example, even if a wind power in a wind power generator is severely fluctuated, the rotation speed of the rotor shaft is constantly maintained by controlling the load of the electric generator according thereto, such that it is possible to stably produce power with a constant frequency without difficulty.
A specific advantage of the present invention is that the rotor magnetic poles 25, which are the protrusions of the rotor 12, and the rotor non-magnetic sections 26, which are recesses, are alternately arranged in the axial direction, and in response thereto, the protrusions of the armature magnetic pole 43a and the recesses of the armature non-magnetic section 44a of the armature 13 are also alternately arranged, such that the range of movement amount of the armature 13 is set as small as the width of the protrusion (corresponding to the length of L1) to cover the severe change range of the motive power and wide frequency fluctuation. Accordingly, there is an advantage that the size of the electric generator does not have to be so large.
In addition, the permanent magnets are buried in the first slots, which are a space formed in the center of the U-shaped magnetic iron piece, and the second slots, which are a space formed between the magnetic iron pieces arranged adjacent to the magnetic iron pieces, such that there is no separate space or shield to block polarity. Therefore, since the alternation is not made rapidly, the magnetic action process in which the rotor magnetic pole and the armature magnetic pole meet and interact is smoothly performed, and the multi-pole configuration of the rotor is easily achieved.
In addition, n first slots are provided by arranging n rotor magnetic iron pieces in n first grooves provided in a direction parallel to the rotor shaft on the outer circumference of the rotor frame, and n second slots are formed between the rotor magnetic iron pieces arranged adjacent to each other. As a result, 2×n rotor magnetic iron cores protrude, and 2×n first and second slots are sunk to form a yoke, thereby forming 2×n multi-pole rotors.
As another advantage of the present invention, in the U-shaped structure of the magnetic iron piece, since residual magnetism is mutually transferred to the magnetic iron core on the opposite side, hysteresis due to the residual magnetism that cannot be converted into electric charge does not occur.
Meanwhile, as the load using electricity induced from the electric generator 10 is increased or decreased, the magnitude of the Lorentz force is also increased or decreased in proportion to the load, and the force acts on the electric generator 10 to cause a slip frequency in the armature 13. Thereby, the frequency of the electricity induced from the armature has a difference from the alternating frequency of the rotor 12. Therefore, it is preferable that the speed sensor 48 for detecting the rotation speed of the rotor shaft 14 is used, and the detected results are utilized as information to check the operation state between the prime mover 15 and the electric generator 10. In addition to the speed sensor 48, when adding a power meter 55 for measuring the frequency and voltage of electrical energy converted by the electric generator in real time, for example, a sensor that detects a fluctuation in the frequency or voltage of electricity induced from the output terminal in real time, etc. detection information of the added sensor is used together with the detection information of speed sensor 48 to control the power generation system so that electricity with a prescribed frequency is induced from the output terminal against the fluctuation in the motive power or the fluctuation in the load amount, such that the system is highly effective. In particular, the ring-shaped gaps formed by the recesses between the armature and the rotor naturally act as a passage for heat dissipation, such that a high-speed and high-efficiency electric generator may be implemented. Further, by simply resetting the frequency on the control panel of the controller, it is possible to induce electricity with a frequency suitable for use by the electricity consumer.
In addition, by operating the storage battery 50 or a separate load device 53, not only the operation of the electric generator 10 but also the operation of the prime mover 15 and the operation of the separate load device may be stabilized. Furthermore, information is provided to the operation control system of the prime mover so as to increase or decrease the output of the motive power, and information is provided to the load control system 54 so as to execute prevention of load short circuit or load sharing. Therefore, organic safe operation and energy efficiency may be achieved in such a co-operation environment.
On the other hand, the Lorentz force proportional to the magnitude of the load using the electricity induced from the electric generator 10 acts on the armature 13 of the electric generator 10, thereby generating an armature slip frequency. Therefore, the controller 49 controls so as to move the armature 13 to the correct position based on the information detected by the power meter 55 (for example, a sensor for measuring an output voltage or frequency, and the speed sensor, etc.) at the output terminal in consideration of even armature slip frequency, such that the problem of the armature slip frequency may be solved, and electrical energy with a precise prescribed frequency may be induced.
Accordingly, the controller 49 detects the frequency and voltage information of the electricity output from the electric generator 10 by the power meter 55, in addition to the speed sensor 48 that detects the rotation speed of the rotor shaft 14, and of course, it may be possible to control the movement of the armature 13 based on each of these information or integrated information.
Meanwhile, although not specifically shown in the drawing, according to the configuration of another embodiment of the present invention, when the electric generator has a small size, it may be configured in such a way that, without being necessary to provide linear bearings and guide rails on the inner circumference of the electric generator case and the outer circumference of the armature frame, a center guide provided in the bearing housing is formed in a polygonal shape, and polygonal sleeves or linear bearings are installed in the center of the side frames installed at both ends of the armature, such that the armature can be supported by these sleeves or bearings so as to be linearly reciprocated.
While the present invention has been described with reference to the preferred embodiments, these embodiments are intended to illustrate the present invention, and are not intended to limit the same, as well as it would be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the present invention. Thereby, the scope of the present invention is not limited to the above-described embodiments, and will be defined by the appended claims as well as their equivalents.
10: Electric generator
11: Electric generator case
11
a, 11b: Left and right covers of case
12: Rotor
13: Armature
14: Rotor shaft
15: Prime mover
16, 16a: Bearing
17. 17a: Bearing housing
18: Clearance (moving space L1)
19: LM guide mechanism
19
a: LM guide rail
19
b: LM guide bearing
20: Support member
21: Rotor frame
22: Protective cover
23: Magnetic iron piece
24: First groove
25: Rotor magnetic pole
26: Rotor non-magnetic section
27: First slot
28: Magnetic pole concentration part (head part)
29: First permanent magnet set
30: Second slot
31: Second permanent magnet set
32: Rotor magnetic pole tip
33: Rotor non-magnetic portion
34: Armature frame
35: Second groove
36: Side frame
37
a: Exhaust passage
37
b: Exhaust passage
38: Armature magnetic iron piece
39: Armature magnetic iron core (side wall)
40: First slot
41: Second slot
42: Armature winding
43: Armature magnetic pole tip
44: Armature non-magnetic portion
43
a: Armature magnetic pole
44
a: Armature non-magnetic section
45: Separation space
46: Linear motor
47: Power transmission mechanism
18: Speed sensor
49: Controller
50: Storage battery
51: Inverter
52: Automatic voltage regulator
53: Separate load device
54: Load control system
55: Electrical measurement sensor
56: Concave and convex coupling part
57: Step portion
t1, t2: Gap (space)
Number | Date | Country | Kind |
---|---|---|---|
10-2018-0132504 | Oct 2018 | KR | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/KR2019/014112 | 10/25/2019 | WO | 00 |