Eco-friendly generator using multi-phase winding-active driving motor

Abstract

The present invention relates to a linear generator in which a stator having multi-phase winding and a motor for independently controlling a mover are combined with a free-piston engine (FPE) internal combustion engine. The eco-friendly generator, according to the present invention, has a relatively simple structure in terms of mechanical aspects, thereby having high reliability and durability, and a very high fuel / energy efficiency compared to weight and volume, and also having high output. In addition, the motor may implement strong spring and damper functions, thereby implementing an eco-friendly generator that does not require a separate physical spring and damper.

Description

Eco-friendly generator using multi-phase winding-active drive motor

[0001] The present invention relates to an eco-friendly generator, and more particularly, to an eco-friendly generator having a high-output, high-efficiency electric motor and an internal combustion engine that utilizes eco-friendly fuel, by combining a linear generator with a Free-Piston Engine (FPE) internal combustion engine and an electric motor composed of multi-phase windings for both the stator and the mover.

[0002] While a piezoelectric engine consists of a piston and crankshaft to generate power, a free piston engine (FPE) is an internal combustion engine that is not restricted by the mechanical connection between the piston and crankshaft. Because there is no crank to restrict piston movement, FPE engines experience less mechanical friction loss. Furthermore, FPEs can freely adjust the piston compression ratio, enabling them to convert chemical energy into electrical energy with greater efficiency than rotary automotive engines. Furthermore, FPEs can operate as eco-friendly generators, using various energy sources (fuels) such as compressed air, biofuel (alcohol), hydrogen, and gasoline.

[0003] However, conventional linear alternators primarily utilize permanent magnet motors as generators, which have limited output. Furthermore, these linear alternators require additional mechanical structures, such as springs and dampers, increasing mechanical complexity and, consequently, weight and volume.

[0004] The purpose of the present invention to solve the above problems is to provide a high-efficiency, eco-friendly generator by fusing a generator / motor that actively drives a stator and a mover having multiple phase windings with an internal combustion engine.

[0005] As an implementation example for achieving the above object, according to one embodiment of the present invention, a linear generator includes a stator including a multi-phase winding, a mover including the multi-phase winding and spaced apart from the stator by a predetermined interval, and a control unit independently controlling a first magnetic field of the stator and a second magnetic field of the mover, wherein the control unit independently controls the first magnetic field and the second magnetic field so that the first magnetic field of the stator and the second magnetic field of the mover are coupled to each other; and an internal combustion engine including at least one cylinder, at least one piston coaxially aligned with the cylinder and freely moving within the cylinder, and at least one combustion chamber defined by the piston and the cylinder for combusting fuel.

[0006] Accordingly, the following effects are expected through the means of solving the above-mentioned problem.

[0007] An eco-friendly generator according to the present invention is implemented by integrating a generator / motor that actively drives a stator and a mover with multi-phase windings with an FPE. This eco-friendly generator has a relatively simple mechanical structure, thus achieving high reliability and durability, and achieving an eco-friendly generator with very high output and energy conversion efficiency relative to its weight and volume. In addition, the eco-friendly generator according to the present invention can achieve a high energy yield and a wide energy harvesting range. The electric motor can implement strong spring and damper functions, thereby enabling the implementation of an eco-friendly generator that does not require separate physical springs and dampers.

[0008] FIG. 1 is a block diagram of a linear motor among electric motors according to one embodiment of the present invention.

[0009] FIG. 2 is a first schematic conceptual diagram of a generator utilizing an electric motor according to one embodiment of the present invention.

[0010] FIG. 3 is a second schematic conceptual diagram of a generator utilizing an electric motor according to one embodiment of the present invention.

[0011] FIG. 4 is a schematic third conceptual diagram of a generator utilizing an electric motor according to one embodiment of the present invention.

[0012] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. The advantages and features of the present invention, as well as the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the attached drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in various forms. Rather, the embodiments introduced herein are provided to ensure that the disclosure is thorough and complete and to sufficiently convey the spirit of the present invention to those skilled in the art, and the present invention is defined solely by the scope of the claims. In addition, like reference numerals refer to like elements throughout the specification.

[0013] The terminology used herein is for the purpose of describing embodiments only and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise. The words “comprises” and / or “comprising” used in this specification do not exclude the presence or addition of one or more other components, steps, operations, and / or elements, as mentioned in the specification. In addition, since it is according to a preferred embodiment, reference numerals presented according to the order of description are not necessarily limited to that order. In addition, in this specification, when a certain component or part is mentioned, it means that other components or parts may also be additionally included if necessary.

[0014] The descriptions and examples provided herein are presented for illustrative purposes only and are not intended to limit the scope of the appended claims. This specification should be considered illustrative of the principles of the invention and is not intended to limit the claimed embodiments and / or the spirit and scope of the invention. Those skilled in the art will recognize that modifications to the invention will be apparent to those skilled in the art to suit their particular applications.

[0015] In addition, the embodiments described herein will be described with reference to cross-sectional views and / or plan views, which are ideal examples of the present invention. In the drawings, the thicknesses of films and regions are exaggerated for effective explanation of the technical contents. Therefore, the shape of the illustrative drawings may be modified due to manufacturing techniques and / or tolerances, etc. Accordingly, the embodiments of the present invention are not limited to the specific shapes shown, but also include changes in shapes produced according to the manufacturing process. For example, an etched region shown at a right angle may be rounded or have a shape with a predetermined curvature. Therefore, the regions illustrated in the drawings have schematic properties, and the shapes of the regions illustrated in the drawings are intended to illustrate specific shapes of regions of the device and are not intended to limit the scope of the invention.

[0016] The technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0017] Fig. 1 is a block diagram of a linear motor among electric motors according to one embodiment of the present invention. In Fig. 1, a generator according to one embodiment of the present invention utilizes a multi-phase winding-active drive electric motor (200) including a stator (210), a mover (220), and a control unit (230).

[0018] The stator (210) and the mover (220) of the multi-phase winding-active drive electric machine (200) each include multi-phase windings (211, 221) and are formed spaced apart from each other by a predetermined interval (d). The control unit (230) independently controls the first magnetic field of the stator (210) and the second magnetic field of the mover (220). By controlling the direction of the current flowing in the multi-phase winding, a magnetic field is formed by the current, and by controlling the current flowing in the multi-phase winding, the speed or direction of the magnetic field can be controlled.

[0019] The control unit (230) can control the first magnetic field and the second magnetic field by controlling the first current applied to the multi-phase winding (211) of the stator (210) and the second current applied to the multi-phase winding (221) of the mover (220). In addition, the control unit (230) can individually control the phase and amplitude of the first current and the second current.

[0020] The control unit (230) can control the first magnetic field of the stator (210) and the second magnetic field of the mover (220) to be coupled to each other at the initial stage of driving the electric motor (200). The control unit (230) can control the movement directions of the first magnetic field and the second magnetic field to be in the same direction or in opposite directions.

[0021] The multi-phase windings (211, 221) arranged in a linear array can be applied to a linear generator / motor. In addition, the array can have a periodic arrangement structure, so that it can also be applied to a rotary electric machine.

[0022] A small air gap exists between the stator and the motor, allowing the motor to move freely while maintaining a constant air gap relative to the stator. When current flows through the stator's polyphase windings, a periodic magnetic field is generated within the air gap by the stator's polyphase windings. Similarly, when current flows through the motor's polyphase windings, a periodic magnetic field is generated within the air gap by the motor's polyphase windings.

[0023] When the multi-phase windings of the stator are excited by a sinusoidal input current having an appropriate phase difference, a moving magnetic field is generated within the air gap, and when the multi-phase windings of the mover are excited by a sinusoidal input current having an appropriate phase difference, a moving magnetic field is generated within the air gap.

[0024] When a mover moves with respect to a stator at a constant speed, a moving magnetic field generated by a constant current flowing through the polyphase windings of the mover moves as the mover moves. The sinusoidal current flowing through the polyphase windings of the mover generates a moving magnetic field in the direction of movement of the mover. As the mover moves, the moving magnetic field generated by the mover within the air gap moves at a speed determined by the combination of the speed of the moving magnetic field and the speed of the mover. In other words, the speed of the magnetic field generated by the mover within the air gap is the sum or difference of the speed of the mover and the speed of the moving magnetic field.

[0025] The polyphase windings constituting the stator and the mover include two or more individual windings, which generate a periodic magnetic field within the air gap when current flows therethrough. The polyphase windings have an integer multiple of a spatial period or period. When there are two or more phase windings, the second winding is positioned offset by a fixed angle (phase distance) with respect to the first winding. For example, in the case of a two-phase winding, the offset may be 1 / 4 of a period (or 90 electrical degrees), and in the case of a three-phase winding, the offset may be 1 / 6 of a period (or 60 electrical degrees).

[0026] By supplying current to the windings, the total magnetic field generated by all the windings becomes the vector sum of the magnetic fields generated by the currents flowing through each winding. Changing the phase and amplitude of the current flowing through the windings can alter the phase and amplitude of the overall magnetic field.

[0027] The number of spatial periods of the magnetic fields generated by the stator and the mover can be the same. The magnetic fields generated by the mover and the stator, respectively, are controlled to maintain a magnetic field locking state. At this time, the magnetic field generated by the mover maintains a defined phase relationship with the magnetic field generated by the stator, and they repel or attract each other. As the phase of the current flowing in the multi-phase winding of the stator changes, the phase current of the mover changes while maintaining a defined phase relationship with the phase current of the stator. At this time, as the phase of the stator current changes, the magnetic field pattern generated by the stator shifts within the air gap. As the magnetic field generated by the stator shifts, the magnetic field generated by the mover also shifts to maintain field locking.

[0028] If the moving magnetic field of the stator and the moving magnetic field of the mover move in opposite directions and at the same speed, the mover moves at twice the speed of the moving magnetic field of the stator. On the other hand, if the moving magnetic fields move in the same direction and at the same speed, the mover remains stationary.

[0029] When an external force pushes or pulls the motor in the opposite direction of its movement, mechanical power is transmitted to the motor. When the motor is moved by an external force, a small phase shift occurs in the currents flowing in the multiphase windings of the motor and stator. This external force balances the forces generated by the moving elements, driven by the magnetic field and current.

[0030] By independently controlling the phase currents of the stator and the motor, an electric motor according to one embodiment of the present invention can have a wide operating range and reduce response time. Furthermore, compared to electric motors including permanent magnets, the electric motor according to one embodiment of the present invention can flow a larger current, generating greater force and output, while also optimizing efficiency. Furthermore, the electric motor according to one embodiment of the present invention has a fast response speed, making it easy to ensure safety during operation.

[0031] A generator (100) including an electric motor according to one embodiment of the present invention is a generator capable of controlling very large power without a gearbox. Furthermore, since no physical gears are present, it is highly reliable and energy efficient.

[0032] FIG. 2 shows a first schematic conceptual diagram of an eco-friendly generator (100) in which a multi-phase winding-active drive motor (200) is integrated according to one embodiment of the present invention.

[0033] In Fig. 2, a cylinder (240) is provided within a generator (100). A piston (250) is provided within the cylinder (240). The piston (250) has a constant diameter that is slightly smaller than the inner diameter of the cylinder (240), but allows the piston (250) to move freely in the axial direction of the cylinder (240). Meanwhile, the piston (250) is aligned coaxially with the cylinder (240). In addition, a combustion chamber (260) for combusting fuel is provided on one side of the cylinder (240). The combustion chamber (260) has various volumes depending on the position of the piston (250) within the cylinder (240).

[0034] The cylinder (240) is preferably symmetrical about the axis of travel of the piston (250). Although cylinders having other geometric shapes, such as square or rectangular cross-section pistons, could potentially be used to practice the present invention, an arrangement having circular cross-section pistons is preferred.

[0035] The combustion chamber (260) has an intake opening (271), an exhaust opening (272), a fuel injection device (273), and a spark plug (270) arranged at the end of the movement path of the piston (250). Meanwhile, the positions of the spark plug (270), the intake opening (271), the exhaust opening (272), and the fuel injection device (273) are shown as examples to explain one embodiment of the present invention, and such arrangement is not limited thereto.

[0036] Meanwhile, the combustion chamber (260) may further include an oxidizer injection device (not shown) to omit the air intake process, thereby eliminating the intake opening (271). At this time, the oxidizer includes oxygen and air, and the ratio of oxygen / air and fuel is controlled by the controller according to the required output.

[0037] Meanwhile, the spark plug (270) according to one embodiment of the present invention may be replaced with an automatic ignition method depending on the fuel being injected.

[0038] Hereinafter, the power generation process of an eco-friendly generator (100) according to one embodiment of the present invention will be exemplarily described, but this is not intended to limit the scope of the present invention.

[0039] A generator (100) according to one embodiment of the present invention is composed of two strokes: an intake / exhaust stroke and a compression / explosion stroke.

[0040] First, in the intake and exhaust stroke, the piston (250) moves to the BDC (Bottom Dead Center, the state where the combustion chamber has the largest volume) of the combustion chamber (260) of the cylinder (240), and the intake opening (271) and the exhaust opening (272) are opened to supply new air to the combustion chamber (260) and simultaneously discharge the combusted mixed air. At this time, in the eco-friendly generator (100) according to one embodiment of the present invention, the multi-phase winding-active drive electric machine (200) operates as a linear motor.

[0041] Next, in the compression-explosion-expansion stroke, the piston (250) propelled by the electric motor (200) compresses air and moves to the TDC (Top Dead Center, the state where the volume of the combustion chamber is the smallest) of the combustion chamber (260), while the intake opening (271) and the exhaust opening (272) are closed and the air inside the combustion chamber (260) is compressed. At this time, after the air inside the combustion chamber (260) is compressed using the electric motor (200) according to one embodiment of the present invention, fuel is injected into the combustion chamber (260) through the fuel injector (273), and after the fuel and oxidizer (air) are mixed, combustion of the mixture is initiated by the spark plug (270). Thereafter, the mixture inside the combustion chamber (260) is combusted to generate heat and oxides, and the piston (250) is pushed by expansion caused by the heat and oxides inside the combustion chamber (260). At this time, the electric motor (200) according to one embodiment of the present invention operates as a generator and produces electricity until expansion stops.

[0042] The fuel used in the eco-friendly generator (100) according to one embodiment of the present invention may be an eco-friendly fuel such as biofuel or hydrogen, but is not limited thereto. Furthermore, depending on the fuel used in the eco-friendly generator (100) according to one embodiment of the present invention, the structure of the generator (100) described above may be partially modified, and the power generation operation process may also be modified accordingly.

[0043] Meanwhile, the eco-friendly generator (100) according to one embodiment of the present invention may further include a control means (not shown) capable of controlling the piston (250) moving speed and the expected compression ratio of air and fuel, output, ignition timing, etc., which affect the power generation efficiency. That is, since the stator (210) and the mover (220) of the electric machine (200) according to one embodiment of the present invention are actively driven, the speed and acceleration of the electric machine (200) can be controlled to dynamically set the TDC and BDC to optimize efficiency, and the ignition timing can also be adjusted to increase the combustion efficiency of air and fuel.

[0044] In addition, an electric motor (200) according to one embodiment of the present invention operates as a linear motor that reciprocates, and can store energy by compressing air using a free-piston engine and generate electricity by utilizing the stored compressed air. In other words, it is possible to use eco-friendly renewable energy to store compressed air in a tank and generate electricity by utilizing the stored compressed air.

[0045] FIG. 3 shows a second schematic conceptual diagram of an eco-friendly generator (100) in which a multi-phase winding-active drive motor (200) is integrated according to one embodiment of the present invention.

[0046] In Fig. 3, opposed pistons (251, 252) are provided within a cylinder (240) of a generator (100). The pistons (251, 252) have a constant diameter that is slightly smaller than the inner diameter of the cylinder (240), but allows the pistons (251, 252) to move freely along the length of the cylinder (240). Meanwhile, the pistons (251, 252) are coaxially aligned with the cylinder (240). Meanwhile, a combustion chamber (260) for combusting fuel is provided at the center of the cylinder (240). An intake opening (271), an exhaust opening (272), and a spark plug (270) including a fuel injector (273) are arranged in the combustion chamber (260). Meanwhile, the positions of the spark plug (270), intake opening (271), exhaust opening (272), and fuel injection device (273) are shown as examples to explain one embodiment of the present invention, and are not limited to this arrangement. In addition, the spark plug (270) according to one embodiment of the present invention may be excluded in the case of automatic ignition.

[0047] A generator (100) according to one embodiment of the present invention operates similarly to the generator (100) of the first concept illustrated in FIG. 2. Meanwhile, the power generation operation process may also be changed depending on the fuel and structure used in the eco-friendly generator (100) according to one embodiment of the present invention.

[0048] FIG. 4 shows a schematic third conceptual diagram of an eco-friendly generator (100) in which a multi-phase winding-active drive motor (200) is integrated according to one embodiment of the present invention.

[0049] In Fig. 4, a single piston (255) is provided with dual pistons combined in a sealed cylinder (240) within a generator (100), the ends of which are connected to an electric motor (200). The piston (255) is slightly smaller than the inner diameter of the cylinder (240), but has a constant diameter that allows the piston (255) to move freely along the length of the cylinder (240). Meanwhile, the piston (255) is connected to separate combustion chambers (263, 265). Meanwhile, a mechanical linkage device (not shown) may connect the two pistons to ensure symmetrical piston behavior.

[0050] A generator (100) according to one embodiment of the present invention operates in a manner similar to that described above. Furthermore, the power generation operation process may vary depending on the fuel and structure used in the eco-friendly generator (100) according to one embodiment of the present invention.

[0051] Meanwhile, this type of opposing piston engine has advantages in terms of system balance and vibration compared to other types of free piston engines, and can have high scavenging efficiency due to reduced heat transfer loss due to the absence of a cylinder head.

Claims

1. Including electric motors and internal combustion engines, The above electric motor, A stator comprising multi-phase windings; A mover including a multi-phase winding and spaced apart from the stator by a predetermined interval; and Including a control unit that independently controls the first magnetic field of the stator and the second magnetic field of the mover, The control unit independently controls the first magnetic field and the second magnetic field while maintaining the first magnetic field of the stator and the second magnetic field of the mover coupled to each other, The above internal combustion engine, At least one cylinder; At least one piston coaxially aligned with the cylinder and moving within the cylinder; and A linear generator characterized by including at least one combustion chamber for burning fuel within a space formed by the piston and the cylinder.

2. In paragraph 1, The above control unit, A linear generator characterized in that the first magnetic field and the second magnetic field are controlled by controlling the first current applied to the multi-phase winding of the stator and the second current applied to the multi-phase winding of the mover.

3. In paragraph 2, The above control unit, A linear generator characterized in that the phase and amplitude of the first current and the second current are individually controlled.

4. In paragraph 1, The above combustion chamber, A linear generator characterized by including at least one opening 5. In paragraph 4, The above opening is, A linear generator, characterized by comprising at least one intake opening.

6. In paragraph 4, The above opening is, A linear generator, characterized in that it further comprises at least one oxidizer injection device.

7. In paragraph 4, The above opening is, A linear generator, characterized by comprising at least one exhaust opening.

8. In paragraph 1, The above combustion chamber, A linear generator, characterized in that it comprises at least one spark plug.

9. In paragraph 8, The above spark plug, A linear generator, characterized in that it further comprises at least one fuel injector.

10. In paragraph 1, The above pistons are composed of a pair, The above combustion chamber It is formed by the space formed by the above cylinder and the pair of above pistons, Each of the above pair of pistons, A linear generator characterized in that it is coupled to the electric motor at one end distant from the combustion chamber.

11. In paragraph 10, The above combustion chamber, A linear generator characterized in that it is disposed between the pair of pistons.

12. In paragraph 11, The above combustion chamber, A linear generator characterized in that when the pair of pistons approach each other, the volume decreases, and when they move away from each other, the volume increases.

13. In paragraph 1, The above piston, A linear generator characterized by two pistons having a single piston structure.

14. In paragraph 13, The above combustion chamber, A linear generator characterized by comprising two combustion chambers separated by the piston.

15. In paragraph 14, The above combustion chamber, A linear generator characterized in that as the volume of one combustion chamber increases in the direction of movement of the piston, the volume of the other combustion chamber decreases.

16. In paragraph 14, Each of the two above separated combustion chambers, A linear generator characterized by comprising at least one opening.

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