Compound slot wedge structure for inhibiting rotor eddy current of two-axis excitation phase modifier and two-axis excitation motor

Abstract

The application provides a composite slot wedge structure for inhibiting rotor eddy current of a two-axis excitation phase modifier and a two-axis excitation motor, and belongs to the technical field of two-axis excitation motors. Compared with a traditional slot wedge structure, the two-axis excitation motor adopts a double-layer composite slot wedge structure of a hard bakelite slot wedge and an aluminum bronze slot wedge, so that the two-axis excitation motor has the damping capacity and the ability of reducing eddy current at the same time, can guarantee the damping and oscillation inhibition capacity of the two-axis excitation motor, and can also run asynchronously with a large slip. The inertia support capacity of the two-axis excitation motor is improved, and the frequency stability of a power system is guaranteed. A multi-branch path ventilation groove is alternately connected by single branches and double branches, the winding heat dissipation area is significantly increased, and the turn conductor heat dissipation coefficient is improved. The stepped auxiliary slot ventilation groove and the unequal outlet diameters of the hard bakelite slot wedge are beneficial to improving the air flow distribution uniformity in each radial ventilation groove and reducing the rotor winding axial thermal imbalance.

Description

Technical Field

[0001] This invention relates to the field of dual-axis excitation motor technology, specifically to a composite slot wedge structure for suppressing eddy currents in the rotor of a dual-axis excitation phase shifter and a dual-axis excitation motor. Background Technology

[0002] The rise of new energy sources, primarily wind and solar power, has drastically altered the grid's structure and operational characteristics. Synchronous generators, which possess strong transient voltage support and overload capacity, have been largely replaced by new energy power generation, resulting in a significant shortage of dynamic reactive power. A single AC fault in a core area can trigger global voltage instability, posing a significant challenge to voltage stability. Synchronous condensers are widely used at the UHVDC transmission and receiving ends, playing a crucial role in suppressing DC commutation failures and improving system voltage stability.

[0003] However, based on the current capacity ratio of synchronous condensers to new energy power generation at 1:5, the increase in the inertia constant H of the new energy source is 0.5~0.6s. It is generally considered that a system inertia constant H less than 2s indicates a severe inertia deficiency; therefore, the inertia support capability of synchronous condensers needs improvement. Simultaneously, due to the limitation of zero minimum excitation current, the leading-phase non-functionality of synchronous condensers is far inferior to that of lagging-phase non-functionality during forced excitation, resulting in insufficient ability to suppress system overvoltage. The new dual-shaft excitation synchronous motor (hereinafter referred to as "dual exciter") is a special type of synchronous motor that operates synchronously under normal conditions and can operate asynchronously at variable speeds as needed under fault conditions.

[0004] However, the inertia increase of a dual-shaft exciter motor is achieved through active changes in its own rotational speed, and its inertial support capability depends on its allowable slip range and duration. Inertia support requires the motor to have the capability for asynchronous operation with large slip over long periods. During asynchronous operation, high-intensity eddy currents and localized high temperatures are generated on the rotor core surface and in the damping windings, severely impacting motor operating safety. Therefore, how to reduce rotor eddy current losses while ensuring the asynchronous operation capability of the dual-shaft exciter motor is a key problem that needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a composite slot wedge structure for suppressing eddy currents in the rotor of a dual-axis excitation synchronous condenser and a dual-axis excitation motor. To ensure high-speed asynchronous operation capability, the non-conductive properties of the hard bakelite slot wedge are utilized to reduce the generation of eddy currents within the wedge. Simultaneously, to ensure transient operation capability, a composite slot wedge, formed by tenon and mortise joints between the hard bakelite and aluminum bronze slot wedges, is proposed to provide damping. Finally, radial ventilation grooves are created within the hard bakelite and aluminum bronze slot wedges to dissipate heat from the rotor windings, reducing the motor temperature and ensuring the safe and reliable operation of the dual-axis excitation motor. This invention solves at least one of the technical problems existing in the aforementioned background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a composite slot wedge structure for suppressing eddy currents in a dual-axis excitation phase-shifting rotor, comprising a deep-slot rotor core, wherein the deep-slot rotor core is uniformly provided with multiple axial secondary slot ventilation grooves; a rotor winding is provided within the secondary slot ventilation grooves; a wedge-shaped pad is provided on the outer side of the rotor winding, an aluminum bronze slot wedge is provided on the outer side of the wedge-shaped pad, and a hard bakelite slot wedge is provided on the outer side of the aluminum bronze slot wedge; the aluminum bronze slot wedge and the hard bakelite slot wedge are connected by a T-shaped tenon and mortise structure; the ends of each aluminum bronze slot wedge are connected by conductive end rings to form a damping circuit; the wedge-shaped pad is uniformly provided with two rows of radially arranged wedge-shaped pads. The ventilation channels are provided with two rows of radial ventilation channels for the aluminum bronze slot wedges and two rows of radial ventilation channels for the hard bakelite slot wedges. The two rows of radial ventilation channels for the wedge pads, the two rows of radial ventilation channels for the aluminum bronze slot wedges, and the two rows of radial ventilation channels for the hard bakelite slot wedges are interconnected. The rotor winding is provided with multiple multi-path ventilation channels, which are alternately connected by single-radial ventilation channels and double-radial ventilation channels. One end of each multi-path ventilation channel is a single-radial ventilation channel connected to the secondary slot ventilation channel, and the other end is a double-radial ventilation channel connected to the two radial ventilation channels for the wedge pads.

[0008] As a further limitation of the first aspect of the present invention, the deep groove rotor has an elongated groove shape, and the ratio of groove depth to groove width is between 10 and 12.

[0009] As a further limitation of the first aspect of the present invention, the hard bakelite groove wedge is made of a non-magnetic, non-conductive insulating material.

[0010] As a further limitation of the first aspect of the present invention, the aluminum bronze groove wedge is made of a conductive material.

[0011] As a further limitation of the first aspect of the present invention, the thickness of the aluminum bronze groove wedge is adjustable, taking into account both the transient operation capability and asynchronous operation capability of the dual-axis phase shifter.

[0012] As a further limitation of the first aspect of the invention, the thickness of the hard bakelite groove wedge is greater than the penetration depth Δ of the eddy current:

[0013] ;

[0014] Where f is the frequency, μ is the magnetic permeability of aluminum bronze, and σ is the electrical conductivity of aluminum bronze.

[0015] As a further limitation of the first aspect of the present invention, the number of the winding multi-path ventilation groove, the wedge pad ventilation groove, the aluminum bronze groove wedge ventilation groove, and the hard bakelite groove wedge ventilation groove are equal.

[0016] As a further limitation of the first aspect of the present invention, the secondary ventilation channel is in the form of a stepped structure, that is, the cross-sectional area of ​​the secondary channel decreases in a stepped manner from the end to the center of the shaft.

[0017] As a further limitation of the first aspect of the present invention, the outlet of the hard bakelite groove wedge ventilation channel has an unequal diameter, that is, the outlet diameter gradually decreases from the end to the center of the shaft.

[0018] In a second aspect, the present invention provides a dual-axis excitation motor, including a composite slot wedge structure as described in the first aspect for suppressing eddy currents in the rotor of a dual-axis excitation phase modulator.

[0019] The beneficial effects of this invention are as follows: Compared to traditional slot wedge structures, this invention employs a double-layer composite slot wedge structure using hard bakelite slot wedges and aluminum bronze slot wedges, giving it both damping capability and eddy current reduction capability. This ensures the damping and oscillation suppression capabilities of the dual-shaft exciter motor, while also allowing for high-speed asynchronous operation. It improves the inertia support capability of the dual-shaft exciter motor, ensuring frequency stability of the power system. The use of multi-branch radial ventilation channels with alternating single and double branches significantly increases the winding heat dissipation area and improves the heat dissipation coefficient of the turn conductors. Furthermore, the unequal outlet diameters of the stepped secondary slot ventilation channels and the hard bakelite slot wedges help improve the uniformity of airflow distribution within each radial ventilation channel, reducing axial thermal imbalance of the rotor windings.

[0020] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of the invention. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the circumferential-radial structure of the composite slot wedge structure for suppressing eddy currents in the rotor of a dual-axis excitation phase modulator as described in an embodiment of the present invention.

[0023] Figure 2 This is a cross-sectional schematic diagram of the composite slot wedge structure axial-radial ventilation system for suppressing eddy currents in the rotor of a dual-axis excitation phase modulator, as described in an embodiment of the present invention.

[0024] Figure 3 This is a three-dimensional cross-sectional view of the composite slot wedge structure for suppressing eddy currents in the rotor of a dual-axis excitation phase shifter, as described in an embodiment of the present invention.

[0025] Figure 4This is a flowchart illustrating the preparation process of the composite slot wedge structure hard bakelite material for suppressing eddy currents in the rotor of a dual-axis excitation phase modulator, as described in an embodiment of the present invention.

[0026] The components are: 1. Deep slot rotor core; 2. Hard bakelite slot wedge; 3. Aluminum bronze slot wedge; 4. T-shaped tenon and mortise; 5. Under-wedge pad; 6. Secondary slot ventilation groove; 7. Single radial ventilation groove; 8. Double radial ventilation groove; 9. Under-wedge pad radial ventilation groove; 10. Aluminum bronze slot wedge radial ventilation groove; 11. Hard bakelite slot wedge radial ventilation groove; 12. Rotor winding. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0028] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0029] It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as here.

[0030] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or groups thereof.

[0031] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0032] In the description of this specification, 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0033] In the description of this specification, the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this technology 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 technology.

[0034] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of these terms in this art according to the specific circumstances.

[0035] To facilitate understanding of the present invention, the present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. However, the specific embodiments do not constitute a limitation on the embodiments of the present invention.

[0036] Those skilled in the art should understand that the accompanying drawings are merely schematic diagrams of embodiments, and the components in the drawings are not necessarily essential for implementing the present invention.

[0037] This invention provides a composite slot wedge structure for suppressing eddy currents in a dual-axis excitation phase-modulation rotor. The structure includes a deep-slot rotor core, hard bakelite slot wedges, aluminum bronze slot wedges, T-shaped tenons, rotor windings, under-wedge spacers, secondary slots, multi-path directional ventilation grooves in the windings, ventilation grooves in the under-wedge spacers, ventilation grooves in the aluminum bronze slot wedges, and ventilation grooves in the hard bakelite slot wedges. The rotor slots are elongated deep slots with a height-to-width ratio between 10 and 12. The hard bakelite slot wedges are made of non-magnetic and non-conductive insulating material, while the aluminum bronze slot wedges are made of conductive material; the two are tightly connected by three T-shaped tenons. The thickness of the hard bakelite slot wedges should be greater than the penetration depth of the eddy currents, and the ends of each aluminum bronze slot wedge are connected by end rings. The windings employ multi-path ventilation grooves, i.e., alternating single-radial and double-radial ventilation grooves. The secondary slot ventilation grooves are connected to the multi-path directional ventilation grooves in the windings, the under-wedge spacer ventilation grooves, the aluminum bronze slot wedge ventilation grooves, and the hard bakelite slot wedge ventilation grooves. This double-layer composite slot wedge structure can reduce eddy current losses and improve slip during asynchronous operation of the dual-axis excitation synchronous condenser. In addition, the multi-path ventilation grooves in the windings, the aluminum bronze slot wedge ventilation grooves, and the hard bakelite slot wedge ventilation grooves help to dissipate rotor heat and reduce temperature.

[0038] Example 1

[0039] Combination Figures 1 to 3 As shown, this embodiment provides a composite slot wedge structure for suppressing eddy currents in a dual-axis excitation phase modulator rotor, including a deep-slot rotor core 1. The deep-slot rotor core 1 has multiple axial secondary slot ventilation grooves 6 evenly distributed. A rotor winding 12 is disposed within each secondary slot ventilation groove 6. A wedge-shaped pad 5 is disposed on the outer side of the rotor winding 12, and an aluminum bronze slot wedge 3 is disposed on the outer side of the wedge-shaped pad 5. A hard bakelite slot wedge 2 is disposed on the outer side of the aluminum bronze slot wedge 3. The aluminum bronze slot wedge 3 and the hard bakelite slot wedge 2 are connected by a T-shaped tenon and mortise structure 4. The end of each aluminum bronze slot wedge is connected by a conductive... The end rings are connected to form a damping circuit; the wedge pads are evenly provided with two rows of radial ventilation grooves 9, the aluminum bronze slot wedges are evenly provided with two rows of radial ventilation grooves 10, and the hard bakelite slot wedges are evenly provided with two rows of radial ventilation grooves 11; the two rows of radial ventilation grooves of the wedge pads, the two rows of radial ventilation grooves of the aluminum bronze slot wedges, and the two rows of radial ventilation grooves of the hard bakelite slot wedges are correspondingly connected to each other; the rotor winding is provided with multiple multi-path ventilation grooves, which are alternating single radial ventilation grooves 7 and double radial ventilation grooves 8 (such as combined). Figure 1As shown, in this embodiment, the innermost end of the multi-path ventilation ditch is a single radial ventilation ditch, connected to the secondary trough ventilation ditch. The other end of this single radial ventilation ditch connects to two radial ventilation ditches via a transverse ventilation ditch, forming a double radial ventilation ditch. These two parallel radial ventilation ditches then connect to another single radial ventilation ditch via a transverse ventilation ditch. Through this structure, the outermost ends are ultimately connected to two radial ventilation ditches, each connected to a radial ventilation ditch of a wedge-shaped pad. Each multi-path ventilation ditch has a single radial ventilation ditch at one end, connecting to the secondary trough ventilation ditch, and a double radial ventilation ditch at the other end, connecting to a radial ventilation ditch of a wedge-shaped pad.

[0040] The deep-slot rotor has a slender slot shape, with a slot depth to width ratio between 10 and 12. The hard bakelite slot wedges are made of non-magnetic, non-conductive insulating material. Hard bakelite refers to a hard and brittle thermosetting plastic made by hot pressing phenolic resin as a base material with fillers. The composition includes 40% phenolic resin, 42% wood flour, 6% hexamethylenetetramine, 8% talc, 2% stearic acid, 1.5% magnesium oxide, and 0.5% colorant. It has high mechanical strength, is tough and wear-resistant, and dimensionally stable, capable of withstanding the enormous centrifugal force and vibration of a high-speed rotating rotor. It does not melt at high temperatures, and its long-term operating temperature can reach over 160℃. Its short-term temperature resistance is even better, meeting the temperature rise requirements during motor operation. In this embodiment, the insulating part of the composite slot wedge is made of hard bakelite, achieving the following technical effects: Eddy current suppression at its source: Utilizing its non-magnetic and non-conductive nature, the circuit for eddy currents induced by the high-frequency alternating magnetic field inside the slot wedge is directly cut off, fundamentally reducing additional losses and localized overheating caused by eddy currents. Ensuring high-slip asynchronous operation capability: The reduction of eddy currents means a decrease in the additional damping torque caused by eddy currents, thereby ensuring the rapid response and stability of the rotor magnetic circuit under high-slip operation conditions.

[0041] The aluminum bronze channel wedge is a conductive material, a high-strength, functional copper alloy with aluminum as the main alloying element. The parameters of the aluminum bronze are as follows: Aluminum (Al): 9.5 ~ 11.0% - Core function: Forms a high-strength α+β phase, improving heat resistance; Iron (Fe): 3.5 ~ 5.5% - Core function: Refines grains, improving fatigue resistance and wear resistance; Nickel (Ni): 3.5 ~ 5.5% - Core function: Improves high-temperature stability and enhances corrosion resistance; Copper (Cu): Balance - Core function: Matrix, ensuring good electrical and thermal conductivity.

[0042] In this embodiment, the aluminum bronze slot wedge is combined with hard bakelite through a mortise and tenon structure, achieving the following technical effects: Constructing a reliable damping circuit: As a conductive component, it forms a composite structure together with the insulating part of the hard bakelite. During motor transients (such as power grid short circuits or impact loads), it can induce current, generating strong damping torque, effectively suppressing rotor oscillation and ensuring the transient stability and dynamic response capability of the motor. Functional heat dissipation under high strength: Aluminum bronze itself has good thermal conductivity, and radial ventilation grooves can be opened inside it without affecting structural strength. Heat is first transferred from the rotor winding to the highly thermally conductive aluminum bronze slot wedge, and then carried away by cooling gas through the ventilation grooves, solving the heat dissipation bottleneck of high power density motors. Structural synergy and functional integration: Utilizing mortise and tenon connections, the three major functions of insulation (hard bakelite), conductive damping (aluminum bronze), and heat dissipation (ventilation grooves) are integrated into one, ensuring structural integrity while avoiding the risk of loosening at the interface of different materials.

[0043] In specific implementation, the thickness of the aluminum bronze groove wedge is adjustable, taking into account both the transient and asynchronous operation capabilities of the dual-axis phase shifter.

[0044] The thickness of the hard bakelite groove wedge is greater than the penetration depth Δ of the eddy current:

[0045] ;

[0046] Where f is the frequency, μ is the magnetic permeability of aluminum bronze, and σ is the electrical conductivity of aluminum bronze.

[0047] The number of the winding multi-path ventilation grooves, wedge-shaped spacer ventilation grooves, aluminum bronze slot wedge ventilation grooves, and hard bakelite slot wedge ventilation grooves are equal. The secondary slot ventilation grooves are stepped, meaning that the cross-sectional area of ​​the secondary slot decreases in a stepped manner from the end to the shaft center. The outlet of the hard bakelite slot wedge ventilation groove has an unequal diameter, meaning that the outlet diameter gradually decreases from the end to the shaft center.

[0048] Example 2

[0049] In this embodiment 2, a dual-axis excitation motor is provided, including a composite slot wedge structure for suppressing eddy currents in the rotor of a dual-axis excitation synchronous condenser. This structure includes a deep-slot rotor core, hard bakelite slot wedges, aluminum bronze slot wedges, T-shaped tenons, rotor windings, under-wedge spacers, secondary slots, multi-path ventilation grooves for the windings, ventilation grooves for the under-wedge spacers, ventilation grooves for the aluminum bronze slot wedges, and ventilation grooves for the hard bakelite slot wedges. The deep-slot rotor core has a slender slot shape, with a slot depth to slot width ratio between 10 and 12. The hard bakelite slot wedges are made of non-magnetic and non-conductive insulating material, while the aluminum bronze slot wedges are made of conductive material. The hard bakelite slot wedges and the aluminum bronze slot wedges are tightly connected by three T-shaped tenons. The thickness of the hard bakelite slot wedges should be greater than the eddy current penetration depth Δ, obtained using the formula described in embodiment 1. The ends of each aluminum bronze slot wedge are connected by conductive end rings to form a damping circuit. The rotor winding is placed in a deep slot, and the under-wedge spacer is placed between the aluminum bronze slot wedge and the rotor winding. Multi-path ventilation grooves are formed inside the rotor winding, with alternating single-radial and double-radial ventilation grooves. The under-wedge spacer ventilation groove is formed inside the under-wedge spacer, the aluminum bronze slot wedge ventilation groove, and the hard bakelite slot wedge ventilation groove. The secondary slot ventilation groove is connected to the multi-path ventilation groove, the under-wedge spacer ventilation groove, the aluminum bronze slot wedge ventilation groove, and the hard bakelite slot wedge ventilation groove. The number of multi-path ventilation grooves, under-wedge spacer ventilation grooves, aluminum bronze slot wedge ventilation grooves, and hard bakelite slot wedge ventilation grooves are equal, and their size and quantity ensure that the rotor has good cooling performance while meeting electromagnetic performance and mechanical strength requirements.

[0050] The secondary ventilation channel is stepped, meaning that the cross-sectional area of ​​the secondary channel decreases in a stepped manner from the end to the center of the shaft, and the number of steps can be set preferentially; the outlet of the hard bakelite channel wedge ventilation channel has unequal diameters, meaning that the outlet diameter gradually decreases from the end to the center of the shaft, and this can be set preferentially; the thickness of the aluminum bronze channel wedge is adjustable, taking into account both the transient and asynchronous operation capabilities of the dual-axis synchronous condenser, and this can be set preferentially.

[0051] Example 3

[0052] In this embodiment 3, a dual-axis excitation motor is provided, including a composite slot wedge structure for suppressing eddy currents in the rotor of the dual-axis excitation synchronous condenser. This composite slot wedge structure, employing a double-layer composite slot wedge structure of hard bakelite slot wedges and aluminum bronze slot wedges, simultaneously possesses damping capability and eddy current reduction capability, ensuring the damping and oscillation suppression capabilities of the dual-axis excitation motor while allowing for large-speed asynchronous operation. This improves the inertia support capability of the dual-axis excitation motor and ensures the frequency stability of the power system.

[0053] The composite slot wedge structure for suppressing eddy currents in the rotor of the dual-axis excitation phase shifter described in this embodiment is as follows: Figure 1As shown, the structure includes: a deep-slot rotor core 1, a hard bakelite slot wedge 2, an aluminum bronze slot wedge 3, a T-shaped tenon 4, a rotor winding 12, a wedge under-slot pad 5, an auxiliary slot 6, a multi-path ventilation groove 7-8 for the winding, a wedge under-slot ventilation groove 9, an aluminum bronze slot wedge ventilation groove 10, and a hard bakelite slot wedge ventilation groove 11.

[0054] The deep-slot rotor 1 has a slender slot shape, with a slot depth to width ratio between 10 and 12. The hard bakelite slot wedge 2 is made of non-magnetic and non-conductive insulating material, while the aluminum bronze slot wedge 3 is made of conductive material. The hard bakelite slot wedge 2 and the aluminum bronze slot wedge 3 are tightly connected by three T-shaped tenons 4.

[0055] The thickness of the hard bakelite slot wedge 2 should be greater than the penetration depth of the eddy current, obtained by the formula in Example 1. The ends of each aluminum bronze slot wedge 3 are connected by conductive end rings to form a damping circuit. The rotor winding 12 is placed in the deep slot 1, and the under-wedge pad 5 is placed between the aluminum bronze slot wedge 3 and the rotor winding 12. The multi-path ventilation grooves 7-8 of the winding are opened inside the rotor winding, with single radial ventilation grooves 7 and double radial ventilation grooves 8 alternately connected. The under-wedge pad ventilation groove 9 is opened inside the under-wedge pad 5, the aluminum bronze slot wedge ventilation groove 10 is opened inside the aluminum bronze slot wedge 3, and the hard bakelite slot wedge 11 ventilation groove is opened inside the hard bakelite slot wedge 2. The secondary slot ventilation groove 6 is connected to the multi-path ventilation grooves 7-8 of the winding, the under-wedge pad ventilation groove 9, the aluminum bronze slot wedge ventilation groove 10, and the hard bakelite slot wedge ventilation groove 11.

[0056] The number of the multi-branch path ventilation grooves, the under-wedge pad ventilation grooves 9, the aluminum bronze slot wedge ventilation grooves 10, and the hard bakelite slot wedge ventilation grooves 11 are equal. Their size and quantity enable the rotor to have a good cooling effect while meeting electromagnetic performance and mechanical strength requirements, and can be preferably configured. The multi-branch path ventilation grooves include alternating single radial ventilation grooves 7 and double radial ventilation grooves 8.

[0057] The secondary ventilation channel 6 is stepped, meaning that the cross-sectional area of ​​the secondary channel decreases in a stepped manner from the end to the center of the shaft, and the number of steps can be preferably set. The outlet of the hard bakelite groove wedge ventilation channel 11 has an unequal diameter, meaning that the outlet diameter gradually decreases from the end to the center of the shaft, and this can be preferably set.

[0058] The thickness of the aluminum bronze groove wedge 3 is adjustable, taking into account both the transient and asynchronous operation capabilities of the dual-axis camera, and can be set by optimization.

[0059] Compared to traditional structures, this invention employs a double-layer composite slot wedge structure using hard bakelite slot wedges and aluminum bronze slot wedges. This structure simultaneously provides damping and reduces eddy currents, ensuring the damping and oscillation suppression capabilities of the dual-shaft exciter motor while allowing for high-speed asynchronous operation. It also improves the inertia support capacity of the dual-shaft exciter motor, ensuring power system frequency stability. The use of multi-branch radial ventilation channels with alternating single and double branches significantly increases the winding heat dissipation area and improves the heat dissipation coefficient of the turn conductors. Furthermore, the unequal outlet diameters of the stepped secondary slot ventilation channels and the hard bakelite slot wedges help improve the uniformity of airflow distribution within each radial ventilation channel, reducing axial thermal imbalance of the rotor windings.

[0060] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that, based on the technical solutions disclosed in the present invention, various modifications or variations that can be made by those skilled in the art without creative effort should be included within the scope of protection of the present invention.

Claims

1. A composite slot wedge structure for suppressing eddy currents in a dual-axis excitation phase modulator rotor, comprising a deep-slot rotor core, wherein the deep-slot rotor core is uniformly provided with a plurality of axial secondary slot ventilation grooves; rotor windings are disposed within the secondary slot ventilation grooves; characterized in that, The rotor winding is provided with a wedge-shaped pad on its outer side, an aluminum bronze slot wedge on its outer side, and a hard bakelite slot wedge on its outer side. The aluminum bronze slot wedge and the hard bakelite slot wedge are connected by a T-shaped tenon and mortise structure. The ends of each aluminum bronze slot wedge are connected by conductive end rings to form a damping circuit. The wedge-shaped pad has two rows of radial ventilation grooves evenly distributed, the aluminum bronze slot wedge has two rows of radial ventilation grooves evenly distributed, and the hard bakelite slot wedge has two rows of radial ventilation grooves evenly distributed. The two rows of radial ventilation grooves of the wedge-shaped pad, the two rows of radial ventilation grooves of the aluminum bronze slot wedge, and the two rows of radial ventilation grooves of the hard bakelite slot wedge are interconnected. The rotor winding is provided with multiple multi-path ventilation grooves, which are alternating single-radial ventilation grooves and double-radial ventilation grooves. One end of each multi-path ventilation groove is a single-radial ventilation groove connected to a secondary slot ventilation groove, and the other end is a double-radial ventilation groove connected to two wedge-shaped pad radial ventilation grooves respectively.

2. The composite slot wedge structure for suppressing eddy currents in a dual-axis excitation phase-shifting rotor according to claim 1, characterized in that, The deep-slot rotor has a slender slot shape, with a slot depth to slot width ratio between 10 and 12.

3. The composite slot wedge structure for suppressing eddy currents in a dual-axis excitation phase-shifting rotor according to claim 1, characterized in that, The hard bakelite groove wedge is made of non-magnetic and non-conductive insulating material.

4. The composite slot wedge structure for suppressing eddy currents in a dual-axis excitation phase-shifting rotor according to claim 1, characterized in that, The aluminum bronze groove wedge is made of conductive material.

5. The composite slot wedge structure for suppressing eddy currents in a dual-axis excitation phase-shifting rotor according to claim 1, characterized in that, The thickness of the aluminum bronze groove wedge is adjustable, taking into account both the transient and asynchronous operation capabilities of the dual-axis phase shifter.

6. The composite slot wedge structure for suppressing eddy currents in a dual-axis excitation phase-shifting rotor according to claim 5, characterized in that, The thickness of the hard bakelite groove wedge is greater than the penetration depth Δ of the eddy current: ； Where f is the frequency, μ is the magnetic permeability of aluminum bronze, and σ is the electrical conductivity of aluminum bronze.

7. The composite slot wedge structure for suppressing eddy currents in a dual-axis excitation phase-shifting rotor according to claim 1, characterized in that, The number of the winding multi-path ventilation grooves, wedge pad ventilation grooves, aluminum bronze slot wedge ventilation grooves, and hard bakelite slot wedge ventilation grooves are equal.

8. The composite slot wedge structure for suppressing eddy currents in a dual-axis excitation phase-shifting rotor according to claim 1, characterized in that, The secondary ventilation channel is stepped, meaning that the cross-sectional area of ​​the secondary channel decreases in a stepped manner from the end to the center of the shaft.

9. The composite slot wedge structure for suppressing eddy currents in a dual-axis excitation phase-shifting rotor according to claim 1, characterized in that, The outlet of the hard bakelite grooved wedge ventilation channel has an unequal diameter, that is, the outlet diameter gradually decreases from the end to the center of the shaft.

10. A dual-shaft excitation motor, characterized in that, Including the composite slot wedge structure for suppressing eddy currents in the rotor of a dual-axis excitation phase modulator as described in any one of claims 1-9.

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