A permanent magnet generator with stable output voltage

Abstract

This invention relates to a permanent magnet generator with stable output voltage, belonging to the field of permanent magnet generator technology. It includes a housing, a rotor core, and six circumferentially evenly arranged permanent magnets. The rotor core consists of spoke bridges, an outer yoke, and an inner yoke. The spoke bridges, outer yoke, and inner yoke together enclose six independent fan-shaped cavities. Each fan-shaped cavity is equipped with a set of elastic magnetic conductive components. This invention uses the centrifugal force generated by rotor rotation as power, and through the cantilever elastic deformation of the long magnetic conductive elastic arm, it converts the speed change into a progressive adjustment of the rotor's internal magnetic reluctance. By sequentially conducting two leakage magnetic branches (primary and secondary), it achieves excitation magnetic field control over a wide speed range. Unlike existing single-path, single-stage magnetic reluctance adjustment methods, it expands the magnetic reluctance adjustment range without increasing the rotor's radial dimension, while simultaneously meeting the excitation strength requirements under low-speed conditions and the voltage stabilization depth under high-speed conditions.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet generator technology, specifically to a permanent magnet generator with stable output voltage. Background Technology

[0002] Permanent magnet generators are widely used in various power generation scenarios due to their simple structure, high power density, and lack of external excitation. A conventional permanent magnet generator mainly consists of a casing, stator windings, rotor core, and circumferentially arranged permanent magnets. The rotor core connects the inner and outer yokes through a spoke structure. The excitation flux provided by the permanent magnets passes through the rotor magnetic circuit, crosses the air gap, and links with the stator windings, realizing the conversion of mechanical energy into electrical energy.

[0003] In operating scenarios with large speed fluctuations, the excitation flux of the permanent magnet is constant and cannot be adjusted. The induced electromotive force of the generator is positively correlated with the speed, and the output voltage will increase with the increase of speed. Usually, a corresponding voltage stabilization circuit is required to ensure the stability of the output indicators. The existing centrifugal voltage stabilization is a common technical route for permanent magnet generators. The magnetic reluctance adjustment corresponds to the displacement of the magnetic conductor. If a wider speed fluctuation range is to be adapted, the travel of the magnetic conductor needs to be increased, which will correspondingly increase the radial dimension of the rotor. If the structure is kept compact, the adjustable range of magnetic reluctance is limited, making it difficult to simultaneously meet the excitation intensity requirements under low-speed conditions and the voltage stabilization depth under high-speed conditions.

[0004] To address the aforementioned issues, innovative design based on existing methods is urgently needed. Summary of the Invention

[0005] The purpose of this invention is to provide a permanent magnet generator with stable output voltage, in order to solve the problems mentioned in the background art, which are that if a wider range of speed fluctuations is to be adapted, the travel of the magnetic conductor needs to be increased, which will correspondingly increase the radial dimension of the rotor; if the structure is kept compact, the range of adjustable magnetic reluctance is limited. The technical solution of this invention provides a solution that is significantly different from the existing technology, which is too simplistic.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a permanent magnet generator with stable output voltage, comprising a housing, a rotor core, and six permanent magnets evenly arranged circumferentially. The rotor core is composed of a spoke bridge, an outer yoke, and an inner yoke. The spoke bridge, the outer yoke, and the inner yoke together enclose six independent fan-shaped cavities. Each fan-shaped cavity is provided with a set of elastic magnetic conductive components for adjusting the effective working magnetic flux ratio. Each set of the elastic magnetic conductive components includes a base, a long magnetic conductive elastic arm, and a short magnetic conductive elastic arm; One end of the base is located in the inner yoke of the rotor core, and the other end of the base extends to the center of the fan-shaped cavity. The first end of the long magnetically conductive elastic arm is installed on the base away from the inner yoke, and the tail end of the long magnetically conductive elastic arm is connected to a spring, and the other end of the spring is connected to a concave clamping plate. The concave plate is slidably connected to the tail end of the long magnetically conductive elastic arm. The long magnetically conductive elastic arm has its own centripetal pre-bending stress, and in its natural state, the arm body retracts towards the base.

[0007] Preferably, the end of the base facing the inner yoke is integrally formed into an arc-shaped clamping plate, and the base and the arc-shaped clamping plate are stamped from a high-permeability elastic alloy. The arc-shaped clamping plate is interference-fitted with the outer periphery of the inner yoke.

[0008] Preferably, the short magnetically conductive elastic arm is mounted on one side of the first end of the long magnetically conductive elastic arm, and the tail end of the short magnetically conductive elastic arm faces the inner wall of the outer periphery of the fan-shaped cavity.

[0009] Preferably, the concave plate faces the radial sidewall of the spoke bridge as the working surface. When the long magnetic elastic arm opens outward, the working surface fits against the sidewall of the corresponding spoke bridge, connecting the spoke bridge and the base, and adding a leakage magnetic branch.

[0010] Preferably, as the long magnetically conductive elastic arm gradually opens outward, the concave plate and the spoke bridge gradually attach and compress the spring, while the short magnetically conductive elastic arm gradually attaches to the inner wall of the corresponding fan-shaped cavity, connecting the outer yoke and the base, and increasing the secondary leakage magnetic branch path.

[0011] Preferably, the angle between the axis of the short magnetically conductive elastic arm and the axis of the long magnetically conductive elastic arm is 75°~105°.

[0012] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses the centrifugal force generated by rotor rotation as power, and transforms the speed change into a progressive adjustment of the rotor's internal magnetic reluctance through the cantilever elastic deformation of the long magnetic elastic arm. By sequentially conducting the first and second leakage magnetic branches, it achieves excitation magnetic field control over a wide speed range. Unlike the existing single-path single-stage magnetic reluctance adjustment method, it can expand the magnetic reluctance adjustment range without increasing the rotor's radial dimension, while taking into account the excitation intensity requirements under low-speed conditions and the voltage stabilization depth under high-speed conditions, thus adapting to a wider range of speed fluctuation scenarios.

[0013] 2. This invention relies on the long magnetically conductive elastic arm and concave clamping plate of the elastic magnetic conductive component to form a continuous linkage between the two-stage leakage magnetic branch and the speed change. During the entire process of speed increase and decrease, the magnetic reluctance inside the rotor changes smoothly with the speed, thereby continuously adjusting the excitation magnetic field and avoiding the instantaneous fluctuation of output voltage caused by single-stage step magnetic reluctance change, ensuring the stability of the power supply voltage and the power supply quality. It can achieve stable voltage operation without additional electrical control and sensing components, simplifying the overall system structure of the generator and improving the reliability of equipment operation and environmental adaptability. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a side sectional view of the overall structure of the present invention; Figure 3 This is a schematic diagram of the rotor core structure of the present invention; Figure 4 This is a main sectional view of the overall structure of the present invention; Figure 5 This is a schematic diagram of the elastic magnetic conductive component of the present invention under stress. Figure 6 This is a schematic diagram of the concave card plate and the long magnetic elastic structure of the present invention.

[0015] In the diagram: 1. Housing; 2. Rotor core; 21. Spoke bridge; 22. Outer yoke; 23. Inner yoke; 3. Permanent magnet; 4. Fan-shaped cavity; 501. Base; 502. Long magnetic elastic arm; 503. Short magnetic elastic arm; 504. Spring; 505. Concave clamping plate; 506. Arc-shaped clamping plate. Detailed Implementation

[0016] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0017] Please see Figures 1-6 The present invention provides a technical solution: a permanent magnet generator with stable output voltage, including a housing 1, a rotor core 2, and six permanent magnets 3 evenly arranged in the circumferential direction. The rotor core 2 is composed of a spoke bridge 21, an outer yoke 22, and an inner yoke 23. The spoke bridge 21, the outer yoke 22, and the inner yoke 23 together enclose six independent fan-shaped cavities 4. The casing 1 serves as the support base for the entire machine and houses the stator windings. The inner yoke 23, outer yoke 22, and spoke bridge 21 of the rotor core 2 together form the main magnetic circuit of the rotor and enclose six fan-shaped cavities 4. The permanent magnet 3 provides constant excitation by being magnetized radially along the circumference. The main magnetic flux is conducted through the spoke bridge 21 and linked with the stator windings to generate electricity. The fan-shaped cavities 4, as high magnetic resistance regions of the air, force the magnetic flux to concentrate in the main magnetic circuit at the rated speed, ensuring the excitation intensity.

[0018] In one embodiment of the present invention, a set of elastic magnetic conductive components is provided in each sector-shaped cavity 4 to adjust the effective working magnetic flux ratio; each set of elastic magnetic conductive components includes a base 501, a long magnetic conductive elastic arm 502, and a short magnetic conductive elastic arm 503; one end of the base 501 is located in the inner yoke 23 of the rotor core 2, and the other end of the base 501 extends to the center of the sector-shaped cavity 4; the first end of the long magnetic conductive elastic arm 502 is installed at the end of the base 501 away from the inner yoke 23, and the tail end of the long magnetic conductive elastic arm 502 is connected to a spring 504, and the other end of the spring 504 is connected to a concave shape The concave clamping plate 505 is slidably connected to the tail end of the long magnetically conductive elastic arm 502. The long magnetically conductive elastic arm 502 has its own centripetal pre-bending stress, and in its natural state, the arm body retracts towards the base 501. The end of the base 501 facing the inner yoke 23 is integrally formed into an arc-shaped clamping plate 506. The base 501 and the arc-shaped clamping plate 506 are stamped from a high magnetic permeability elastic alloy. The arc-shaped clamping plate 506 is interference-fitted with the outer periphery of the inner yoke 23. The short magnetically conductive elastic arm 503 is installed on one side of the head end of the long magnetically conductive elastic arm 502, and the tail end of the short magnetically conductive elastic arm 503 faces the outer periphery of the fan-shaped cavity 4. The motion assembly consisting of the long magnetically conductive elastic arm 502, the concave clamping plate 505, and the short magnetically conductive elastic arm 503 rotates with the rotor core 2. The whole assembly is subjected to a radially outward centrifugal force F1, which is proportional to the square of the rotational speed. At the same time, it is subjected to a centripetal restoring force in three directions: the centripetal pre-bending stress F2 of the long magnetically conductive elastic arm 502 itself, and the magnetic attraction force F3 of the permanent magnet 3 on the magnetically conductive assembly. When the generator speed is less than or equal to the rated speed, the centrifugal force F1 ≤ F2 + F3, and the long magnetically conductive elastic arm 502 remains in a natural state of retracting towards the base 501. At this time, air gaps exist between the concave clamping plate 505 and the side wall of the spoke bridge 21, and between the short magnetically conductive elastic arm 503 and the inner wall of the outer yoke 22. Both stages of leakage magnetic branches are disconnected, the rotor internal magnetic resistance is at its minimum value, the excitation magnetic field strength is at its maximum value, and the generator output voltage quickly reaches the rated value as the speed increases. When the generator speed is greater than the rated speed, the centrifugal force F1 > F2 + F3, and the long magnetically conductive elastic arm 502 remains in a natural state of retracting towards the base 501. 2. The base 501 is elastically deformed outward with the outer end as the fulcrum, which drives the concave clamping plate 505 to approach and fit against the side wall of the spoke bridge 21. After fitting, the air gap at this position disappears. The spoke bridge 21 forms a circumferential first-order leakage magnetic branch through the concave clamping plate 505, the long magnetic elastic arm 502 and the base 501. The magnetic resistance inside the rotor increases and the excitation magnetic field strength decreases accordingly, which offsets the increase in induced electromotive force caused by the increase in speed and keeps the output voltage stable. Among them, the elastic deformation of the long magnetic elastic arm 502 is positively correlated with the magnitude of the centrifugal force, and the voltage regulation process is smooth.

[0019] In one embodiment of the present invention, the radial sidewall of the concave clamping plate 505 facing the spoke bridge 21 is the working surface. When the long magnetically conductive elastic arm 502 opens outward, the working surface adheres to the sidewall of the corresponding spoke bridge 21, connecting the spoke bridge 21 and the base 501, and adding a first-level leakage magnetic branch. When the long magnetically conductive elastic arm 502 gradually opens outward, the concave clamping plate 505 and the spoke bridge 21 gradually adhere to each other and compress the spring 504. At the same time, the short magnetically conductive elastic arm 503 gradually adheres to the inner wall of the outer periphery of the corresponding fan-shaped cavity 4, connecting the outer yoke 22 and the base 501, and adding a second-level leakage magnetic branch path. The angle between the axes of the short magnetically conductive elastic arm 503 and the long magnetically conductive elastic arm 502 is 75°~105°.

[0020] When the generator speed continues to increase and exceeds the first-level voltage regulation range, the centrifugal force F1 further increases, and the long magnetic elastic arm 502 continues to bend outward. After the concave clamping plate 505 is circumferentially limited by the spoke bridge 21, it slides along the arm of the long magnetic elastic arm 502 towards the tail end and squeezes the spring 504, while simultaneously driving the short magnetic elastic arm 503 to swing outward until the tail end of the short magnetic elastic arm 503 adheres to the inner wall of the outer yoke 22 of the rotor core 2. After adhering, a radial secondary leakage magnetic branch is formed between the base 501 and the outer yoke 22 through the short magnetic elastic arm 503, further increasing the magnetic resistance inside the rotor and the excitation. As the magnetic field strength continues to decrease, the output voltage remains stable over a wider range of high speeds. When the speed drops, the centrifugal force F1 decreases, and under the combined resetting action of F2 and F3, the short magnetic elastic arm 503 and the concave clamp 505 sequentially detach from the contact surface, the two-stage leakage magnetic branches disconnect one after the other, and the excitation magnetic field gradually recovers, maintaining a stable output voltage. The angle between the short magnetic elastic arm 503 and the long magnetic elastic arm 502 ensures that when the secondary leakage magnetic branch is conducting, the tail end of the short magnetic elastic arm 503 forms a stable surface contact with the inner wall of the outer yoke 22, ensuring the magnetic conductivity of the leakage magnetic path.

[0021] Working principle: The motion assembly consisting of the long magnetically conductive elastic arm 502, the concave clamping plate 505, and the short magnetically conductive elastic arm 503 rotates with the rotor core 2. The whole assembly is subjected to a radially outward centrifugal force F1, which is proportional to the square of the rotational speed. At the same time, it is subjected to three centripetal restoring forces: the centripetal pre-bending stress F2 of the long magnetically conductive elastic arm 502 itself, and the magnetic attraction force F3 of the permanent magnet 3 on the magnetically conductive assembly. When the generator speed is less than or equal to the rated speed, the centrifugal force F1 is less than or equal to F2 and F3. The long magnetic elastic arm 502 remains in a natural state of being drawn towards the base 501. At this time, there are air gaps between the concave plate 505 and the side wall of the spoke bridge 21, and between the short magnetic elastic arm 503 and the inner wall of the outer yoke 22. Both leakage magnetic branches are disconnected, the internal magnetic resistance of the rotor is at its minimum value, the excitation magnetic field strength is at its maximum value, and the generator output voltage quickly reaches the rated value as the speed increases. When the generator speed is greater than the rated speed, the centrifugal force F1 is greater than F2 + F3. The long magnetic elastic arm 502 elastically deforms outward with the outer end of the base 501 as the fulcrum, driving the concave clamping plate 505 to approach and fit against the side wall of the spoke bridge 21. After fitting, the air gap at this position disappears, and the spoke bridge 21 forms a circumferential first-order leakage magnetic branch through the concave clamping plate 505, the long magnetic elastic arm 502 and the base 501. The magnetic resistance inside the rotor increases, and the excitation magnetic field strength decreases accordingly, offsetting the increase in induced electromotive force caused by the increase in speed, so that the output voltage remains stable. When the generator speed continues to increase and exceeds the first-level voltage regulation range, the centrifugal force F1 increases further, and the long magnetic elastic arm 502 continues to bend outward. After the concave plate 505 is circumferentially limited by the spoke bridge 21, it slides along the long magnetic elastic arm 502 towards the tail end and squeezes the spring 504, while simultaneously driving the short magnetic elastic arm 503 to swing outward until the tail end of the short magnetic elastic arm 503 adheres to the inner wall of the outer yoke 22 of the rotor core 2. After adhering, a radial secondary leakage magnetic branch is formed between the base 501 and the outer yoke 22 through the short magnetic elastic arm 503, the magnetic resistance inside the rotor further increases, the excitation magnetic field strength continues to decrease, and the output voltage remains stable in a wider high-speed range. When the rotational speed drops, the centrifugal force F1 decreases. Under the combined reset action of F2 and F3, the short magnetic elastic arm 503 and the concave plate 505 successively detach from the contact surface, the two-stage leakage magnetic branches are disconnected one after another, the excitation magnetic field gradually rises, and the output voltage remains stable.

[0022] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A permanent magnet generator with stable output voltage, comprising a housing (1), a rotor core (2), and six permanent magnets (3) evenly arranged circumferentially, wherein the rotor core (2) is composed of a spoke bridge (21), an outer yoke (22), and an inner yoke (23), the spoke bridge (21), the outer yoke (22), and the inner yoke (23) together enclosing six independent fan-shaped cavities (4), characterized in that: Each of the aforementioned sector-shaped cavities (4) is provided with a set of elastic magnetic conductive components for adjusting the proportion of effective working magnetic flux; Each set of the elastic magnetic conductive components includes a base (501), a long magnetic conductive elastic arm (502), and a short magnetic conductive elastic arm (503). One end of the base (501) is disposed in the inner yoke (23) of the rotor core (2), and the other end of the base (501) extends to the center of the fan-shaped cavity (4); The first end of the long magnetically conductive elastic arm (502) is installed on the base (501) at the end away from the inner yoke (23), and the tail end of the long magnetically conductive elastic arm (502) is connected to a spring (504), and the other end of the spring (504) is connected to a concave clamping plate (505). The concave plate (505) is slidably connected to the tail end of the long magnetic elastic arm (502). The long magnetic elastic arm (502) has its own centripetal pre-bending stress, and in its natural state, the arm body retracts towards the base (501).

2. A permanent magnet generator with stable output voltage according to claim 1, characterized in that: The base (501) is integrally formed with an arc-shaped clamping plate (506) at one end facing the inner yoke (23). The base (501) and the arc-shaped clamping plate (506) are stamped from a high-permeability elastic alloy. The arc-shaped clamping plate (506) is interference-fitted with the outer periphery of the inner yoke (23).

3. A permanent magnet generator with stable output voltage according to claim 1, characterized in that: The short magnetically conductive elastic arm (503) is installed on one side of the head end of the long magnetically conductive elastic arm (502), and the tail end of the short magnetically conductive elastic arm (503) faces the inner wall of the outer periphery of the fan-shaped cavity (4).

4. A permanent magnet generator with stable output voltage according to claim 3, characterized in that: The concave plate (505) faces the radial sidewall of the spoke bridge (21) as the working surface. When the long magnetic elastic arm (502) opens outward, the working surface fits the sidewall of the corresponding side spoke bridge (21), connecting the spoke bridge (21) and the base (501), and adding a first-level leakage magnetic branch.

5. A permanent magnet generator with stable output voltage according to claim 4, characterized in that: When the long magnetically conductive elastic arm (502) gradually opens outward, the concave card plate (505) and the spoke bridge (21) gradually attach and compress the spring (504), and the short magnetically conductive elastic arm (503) gradually attaches to the inner wall of the corresponding fan-shaped cavity (4), connecting the outer yoke (22) and the base (501), thus increasing the secondary leakage magnetic branch path.

6. A permanent magnet generator with stable output voltage according to claim 5, characterized in that: The angle between the axes of the short magnetic elastic arm (503) and the long magnetic elastic arm (502) is 75°~105°.

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