Primary and secondary double-sided cooperative hybrid excitation linear motor

Abstract

The application discloses a primary-secondary double-side cooperative hybrid excitation linear motor, which comprises a primary mover and a secondary stator, and an electromagnetic air gap is formed between the primary mover and the secondary stator; the primary mover comprises a primary iron core, a primary permanent magnet and a primary armature winding, the primary permanent magnet and the primary armature winding are arranged on the primary iron core; the secondary stator comprises a secondary permanent magnet, a secondary excitation winding and a back iron, the secondary permanent magnet and the secondary excitation winding are arranged on the back iron. Compared with a conventional permanent magnet linear motor, the structure can significantly improve the air gap magnetic flux density under the same excitation current, enhance the overall magnetic field coupling strength of the motor and improve the material utilization, which not only greatly improves the thrust of the motor, but also further improves the suspension stability of the magnetic levitation vehicle. The performance gain is derived from the magnetic circuit superposition effect generated by the double-side cooperative excitation, rather than the traditional simple magnetic circuit regulation mechanism.

Description

Technical Field

[0001] This invention relates to the field of linear motor technology, and in particular to a primary and secondary dual-sided synergistic hybrid excitation linear motor. Background Technology

[0002] Linear motors are widely used in urban rail transit maglev trains due to their advantages such as simple structure, small turning radius, strong climbing ability, and low noise. Examples include the Changsha Airport Line, Beijing S1 Line, Phoenix Tourist Line, and Qingyuan Tourist Line. Maglev trains rely on electromagnetic force to levitate the train on the track and are propelled forward by linear motors. When a linear motor is energized, it generates both thrust and normal force. Conventional induction linear motors and permanent magnet linear motors, when a fixed current is applied to the primary winding, typically cannot achieve adjustable magnetic flux, meaning the generated magnetic field strength, thrust, and normal force are relatively fixed.

[0003] Chinese patent application No. 201010181039.X discloses a complementary modular hybrid excitation linear motor. The motor only adopts a hybrid excitation structure in the primary winding, and the permanent magnet is placed in the magnetic guide teeth between the primary windings. Due to the severe heat generated by the magnetization of the magnetic guide teeth in the primary winding, the temperature of the permanent magnet rises rapidly, and the magnetic properties will be greatly weakened as the temperature rises. The flux linkage change rate is large, which greatly increases the difficulty of motor control.

[0004] Chinese patent application No. 201310584972.5 discloses a tangentially magnetized flux-reverse hybrid excitation linear motor. This motor only adopts a hybrid excitation structure in the primary stage, and the magnetic field generated by the two armature teeth on both sides of the primary module will flow through the middle excitation tooth. The width of the excitation tooth is significantly reduced compared to the armature tooth. At the same time, it does not have two tangential permanent magnets with opposite polarities at the end like the armature tooth, which makes the excitation tooth prone to magnetic saturation.

[0005] Chinese patent application No. 201510251318.1 discloses a dual-sided hybrid excitation linear motor. This motor uses a hybrid excitation structure only in its secondary stage and primarily serves as the air gap adjustment unit in a magnetic levitation system. Attitude adjustment in the X and Y directions is achieved by controlling the secondary excitation current, while the thrust mainly depends on the primary stage. Its control strategy is as follows: by applying a DC excitation current, the excitation magnetic field and normal force on the secondary side are enhanced while the other side is weakened, keeping the total electromagnetic thrust constant. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a primary and secondary dual-sided synergistic hybrid excitation linear motor that is conducive to improving air gap magnetic flux density, enhancing the overall magnetic field coupling strength of the motor and improving material utilization.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A primary and secondary dual-sided coordinated hybrid excitation linear motor includes a primary mover and a secondary stator, wherein an electromagnetic air gap exists between the primary mover and the secondary stator. The primary mover includes a primary iron core, a primary permanent magnet, and a primary armature winding, wherein the primary permanent magnet and the primary armature winding are disposed on the primary iron core; The secondary stator includes a secondary permanent magnet, a secondary excitation winding, and a back iron, wherein the secondary permanent magnet and the secondary excitation winding are disposed on the back iron.

[0008] As a further improvement to the above technical solution: the secondary excitation winding includes an independently controlled primary excitation winding and a secondary excitation winding. The back iron has multiple protruding teeth on the side near the primary iron core. The primary excitation winding is wound around the protruding teeth of the back iron in a first direction, and the secondary excitation winding is wound around the yoke of the back iron in a second direction, the second direction being perpendicular to the first direction.

[0009] As a further improvement to the above technical solution: the positive and negative poles of the secondary permanent magnet are alternately distributed on the protruding teeth of the back iron.

[0010] As a further improvement to the above technical solution: the yoke of the back iron is provided with a groove, and the second-stage excitation winding is disposed in the groove.

[0011] As a further improvement to the above technical solution: both the first-stage excitation winding and the second-stage excitation winding adopt a single-layer concentrated winding.

[0012] As a further improvement to the above technical solution: the primary permanent magnet is embedded in the yoke of the primary iron core.

[0013] As a further improvement to the above technical solution: along the length direction of the primary iron core, the distance between the primary permanent magnet and the two adjacent excitation teeth is equal.

[0014] As a further improvement to the above technical solution: the distance between the top of the primary permanent magnet and the top of the yoke of the primary iron core is equal to the distance between the bottom of the primary permanent magnet and the top of the tooth of the primary iron core, and the primary permanent magnets are equidistantly distributed along the length direction of the primary iron core.

[0015] As a further improvement to the above technical solution: the widths of the excitation teeth of the primary iron core are equal.

[0016] As a further improvement to the above technical solution: the primary armature winding adopts a single-layer concentrated winding.

[0017] Compared with existing technologies, the advantages of this invention are as follows: The primary and secondary dual-sided synergistic hybrid excitation linear motor disclosed in this invention comprises a primary permanent magnet and a primary armature winding in the primary stator, and a secondary permanent magnet and a secondary excitation winding in the secondary stator. Both the primary and secondary stages adopt a synergistic hybrid excitation structure. Compared with conventional permanent magnet linear motors, this structure can significantly improve the air gap magnetic flux density under the same excitation current, enhance the overall magnetic field coupling strength of the motor, and improve material utilization. This not only greatly increases the motor thrust but also further improves the levitation stability of magnetic levitation vehicles. The aforementioned performance gains originate from the magnetic circuit superposition effect generated by dual-sided synergistic excitation, rather than from the traditional simple magnetic circuit adjustment mechanism.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the primary and secondary dual-sided cooperative hybrid excitation linear motor of the present invention.

[0020] Figure 2 This is a top view of the primary iron core in this invention.

[0021] Figure 3 This is a schematic diagram of the magnetic field analysis model of the primary and secondary dual-sided coordinated hybrid excitation linear motor of the present invention.

[0022] Figure 4 This is a schematic diagram of the magnetic flux path of a single phase of the primary and secondary dual-sided coordinated hybrid excitation linear motor of the present invention.

[0023] Figure 5 This is a comparison diagram of the air gap magnetic flux density of the present invention and that of a conventional permanent magnet linear motor.

[0024] Figure 6 This is a comparison diagram of the magnetic flux density distribution cloud map of the present invention and that of a conventional permanent magnet linear motor, wherein (a) is the magnetic flux density distribution cloud map of a conventional permanent magnet linear motor and (b) is the magnetic flux density distribution cloud map of the present invention.

[0025] Figure 7 This is a comparison chart of the thrust of the present invention and a conventional permanent magnet linear motor.

[0026] Figure 8 This is a comparison diagram of the normal force of the present invention and that of a conventional permanent magnet linear motor.

[0027] The labels in the diagram represent: 1. Primary iron core; 2. Primary permanent magnet; 3. Primary armature winding; 4. Secondary permanent magnet; 5. First primary excitation winding; 6. Back iron; 7. Secondary excitation winding. Detailed Implementation

[0028] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] In this invention, unless otherwise explicitly specified and limited, the terms "assembly," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Figure 1 , Figure 2 and Figure 4 An embodiment of the primary and secondary dual-sided cooperative hybrid excitation linear motor of the present invention is shown. The primary and secondary dual-sided cooperative hybrid excitation linear motor of this embodiment includes a primary mover and a secondary stator, and there is an electromagnetic air gap g0 between the primary mover and the secondary stator.

[0033] The primary mover includes: a primary iron core 1, a primary permanent magnet 2, and a primary armature winding 3. The length direction of the primary iron core 1 is taken as the X-axis direction, and the height direction is taken as the Y-axis direction. The effective length of the primary iron core 1 is L2, the effective width is L1, and the tooth width is b. z The groove width is b s The tooth pitch is t z The height of the yoke is h c The tooth height is h sThe yoke has slots for embedding the rectangular primary permanent magnet 2. The primary armature winding 3 is a single-layer concentrated winding, wound around the teeth of the primary iron core 1. The primary permanent magnet 2 is rectangular, with a length of L. z Width is L q Embedded in b s The primary core yoke corresponds to the slot position at a distance of / 2 (i.e., the distance between the primary permanent magnet 2 and the two adjacent excitation teeth is equal), and the distance between the bottom of the primary permanent magnet 2 and the top of the slot is L. k The distance between the top of the primary permanent magnet 2 and the top of the yoke is also L. k They are distributed at equal intervals W along the x-axis.

[0034] The secondary stator includes: a secondary permanent magnet 4, a primary excitation winding 5, a back iron 6, and a secondary excitation winding 7, wherein the height of the back iron 6 is h. z It has protruding teeth and grooves for embedding the excitation winding. The height of the secondary permanent magnet 4 is h. p The width is the same as the width of the convex tooth, which is τ. p The pole spacing is τ, and the positive and negative poles are alternately distributed on the secondary back iron convex teeth. The primary excitation winding 5 adopts a single-layer concentrated winding, which is wound on the back iron convex teeth along the x-axis. The secondary excitation winding 7 adopts a single-layer concentrated winding, which is wound on the back iron yoke along the y-axis.

[0035] The structure of the primary and secondary dual-sided coordinated hybrid excitation linear motor is equivalently represented by a magnetic field analysis model, such as... Figure 3 As shown, from the Maxwell equations (1), we can derive the formulas (2) for calculating thrust, normal force, and magnetic flux.

[0036] (1) (2) in: For thrust, For normal force, air permeability, This refers to the number of turns per phase of the stator winding. This is the primary winding current. p For extreme logarithms, This represents the spatial phase angle between the fundamental wave of the traveling wave magnetomotive force of the primary winding and the fundamental wave of the excitation. sh Represents a hyperbolic sine function. ch Represents the hyperbolic cosine function. J s The primary equivalent surface current density, J m The secondary equivalent surface current density, This is the polar arc coefficient. H pThe magnetic field strength of the secondary permanent magnet. H z The magnetic field strength generated by the two sets of secondary excitation windings. For a pair of lower pole magnetic fluxes, It is the air gap magnetic flux density.

[0039] As can be seen from the formulas for calculating thrust and normal force, once the motor structure and dimensions are determined, a constant current flows through the primary armature winding. ,thrust Normal force The magnetic field strength generated by the two sets of secondary excitation windings H z Furthermore, the addition of two sets of secondary excitation windings can achieve coordinated regulation and control of the air gap magnetic flux density. By adjusting the magnetic flux, the magnetic flux can be achieved. adjust.

[0040] Depend on Figure 4 As can be seen, the magnetic field lines of the primary and secondary dual-sided synergistic hybrid excitation linear motor of the present invention are as follows: N-pole permanent magnet → air gap → primary iron core teeth → primary iron core yoke → primary permanent magnet → primary iron core yoke → primary iron core teeth → air gap → S-pole permanent magnet → back iron convex teeth → back iron yoke → N-pole permanent magnet. The primary permanent magnet and the two sets of excitation windings on the secondary side will enhance the overall magnetic field coupling strength of the motor.

[0041] Taking a 9-slot, 8-pole linear motor as an example, a comparison is made between a conventional permanent magnet linear motor and the primary and secondary dual-side hybrid excitation linear motor of this invention. Both motors have their primary windings connected to... I m =12A, frequency f =120Hz three-phase AC power. Furthermore, in this invention, the primary excitation winding of the dual-side hybrid excitation linear motor is supplied with 1A DC power, and the secondary excitation winding is supplied with 0.5A DC power. Comparison diagrams of the motor's air gap magnetic flux density, magnetic flux density distribution cloud map, thrust, and normal force are obtained, as shown below. Figures 5 to 8 As shown.

[0042] Depend on Figure 5 It is known that the air gap magnetic flux density of a conventional permanent magnet linear motor is 1.05T, while the air gap magnetic flux density of the primary and secondary dual-side hybrid excitation linear motor of this invention is 1.36T. Due to the increase of the primary permanent magnet and the two sets of secondary excitation windings in this invention, the air gap magnetic flux density is increased by 29.5%.

[0043] Depend on Figure 6 It can be seen that, due to the addition of the primary permanent magnet and the two sets of secondary excitation windings in this invention, the magnetic flux density distribution cloud map of the primary and secondary dual-side synergistic hybrid excitation linear motor of this invention is significantly enhanced compared with the overall magnetic field coupling strength of the conventional permanent magnet linear motor, and no saturation phenomenon occurs, which greatly improves the utilization rate of motor materials.

[0044] Depend on Figure 7 It is known that the thrust of a conventional permanent magnet linear motor is 215 N·m, while the air gap magnetic flux density of the primary and secondary dual-side hybrid excitation linear motor of this invention is 280 N·m. Due to the addition of the primary permanent magnet and the two sets of secondary excitation windings, the thrust of this invention is increased by 30.2%.

[0045] Depend on Figure 8 It is known that the normal force of a conventional permanent magnet linear motor is -425 N·m, while the normal force of the primary and secondary dual-side hybrid excitation linear motor of this invention is -463 N·m. Due to the addition of the primary permanent magnet and the two sets of excitation windings in the secondary stage, the normal force of this invention is increased by 8.9%.

[0046] This invention relates to a dual-sided hybrid excitation linear motor with primary and secondary windings. Both the primary and secondary windings comprise independent excitation windings (the primary armature winding 3 serves as the primary excitation winding) and permanent magnets, forming a dual-sided hybrid excitation structure. The primary permanent magnet 2 is rectangular and embedded in b. s The primary core yoke, positioned at a distance of / 2, corresponds to a slot position, thus avoiding the problem of severe overheating of the primary winding magnetization guide teeth, which leads to a rapid increase in the permanent magnet temperature. The distance between the primary permanent magnet 2 and the top of both the slot and the top of the yoke is L. k The magnetic flux is evenly distributed along the x-axis (W-axis), achieving balanced magnetic flux distribution in the left and right regions of the primary core yoke. This avoids the problem of excessively high magnetic flux density on one side of the yoke and premature saturation caused by an offset structure, resulting in a more uniform magnetic flux density distribution in the yoke. The primary core excitation teeth adopt an equal-width design, with a symmetrical and balanced magnetic circuit distribution, preventing local magnetic saturation. The two sets of secondary excitation windings can be independently controlled, achieving coordinated adjustment of magnetic flux, thrust, and normal force. Compared with conventional permanent magnet linear motors, this structure can significantly improve the air gap magnetic flux density under the same excitation current, enhance the overall magnetic field coupling strength of the motor, and improve material utilization. This not only greatly increases the motor thrust but also further improves the levitation stability of the magnetic levitation vehicle.

[0047] The aforementioned performance gain stems from the magnetic circuit superposition effect generated by dual-sided synergistic excitation, rather than from the traditional simple magnetic circuit adjustment mechanism.

[0048] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. A primary and secondary dual-sided coordinated hybrid excitation linear motor, characterized in that: It includes a primary mover and a secondary stator, with an electromagnetic air gap between the primary mover and the secondary stator; The primary mover includes a primary iron core (1), a primary permanent magnet (2) and a primary armature winding (3), wherein the primary permanent magnet (2) and the primary armature winding (3) are disposed on the primary iron core (1); The secondary stator includes a secondary permanent magnet (4), a secondary excitation winding, and a back iron (6), with the secondary permanent magnet (4) and the secondary excitation winding disposed on the back iron (6).

2. The primary and secondary dual-sided coordinated hybrid excitation linear motor according to claim 1, characterized in that: The secondary excitation winding includes an independently controlled primary excitation winding (5) and a secondary excitation winding (7). The back iron (6) has multiple protruding teeth on the side near the primary iron core (1). The primary excitation winding (5) is wound around the protruding teeth of the back iron (6) in a first direction. The secondary excitation winding (7) is wound around the yoke of the back iron (6) in a second direction, which is perpendicular to the first direction.

3. The primary and secondary dual-sided coordinated hybrid excitation linear motor according to claim 2, characterized in that: The positive and negative poles of the secondary permanent magnet (4) are alternately distributed on the protrusions of the back iron (6).

4. The primary and secondary dual-sided coordinated hybrid excitation linear motor according to claim 2, characterized in that: The yoke of the back iron (6) is provided with a groove, and the second-stage excitation winding (7) is provided in the groove.

5. The primary and secondary dual-sided coordinated hybrid excitation linear motor according to claim 2, characterized in that: Both the first-stage excitation winding (5) and the second-stage excitation winding (7) adopt a single-layer concentrated winding.

6. The primary and secondary dual-sided coordinated hybrid excitation linear motor according to claim 1, characterized in that: The primary permanent magnet (2) is embedded in the yoke of the primary iron core (1).

7. The primary and secondary dual-sided coordinated hybrid excitation linear motor according to claim 6, characterized in that: Along the length of the primary iron core (1), the distance between the primary permanent magnet (2) and the two adjacent excitation teeth is equal.

8. The primary and secondary dual-sided coordinated hybrid excitation linear motor according to claim 6, characterized in that: The distance between the top of the primary permanent magnet (2) and the top of the yoke of the primary iron core (1) is equal to the distance between the bottom of the primary permanent magnet (2) and the top of the tooth of the primary iron core (1). The primary permanent magnets (2) are equidistantly distributed along the length direction of the primary iron core (1).

9. The primary and secondary dual-sided coordinated hybrid excitation linear motor according to claim 1, characterized in that: The excitation teeth of the primary iron core (1) have equal widths.

10. The primary and secondary dual-sided cooperative hybrid excitation linear motor according to any one of claims 1 to 9, characterized in that: The primary armature winding (3) adopts a single-layer concentrated winding.

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