A structure of an exciter with a function of a sub-exciter

Abstract

The application discloses a kind of exciter structures with auxiliary exciter function, it is related to exciter technical field, to solve the technical problem of current technology in which external equipment is used as initial starting device, system is prone to difficult independent start condition, and auxiliary excitation stability is insufficient, including stator.The application is provided with auxiliary excitation winding assembly, when rotor rotates, auxiliary excitation rotor winding cuts the magnetic field to generate initial alternating current, without relying on external power supply, it can independently start excitation process, so that main excitation system does not need additional starting excitation device, after starting, the magnetic shield prevents the influence of main excitation strong magnetic field on auxiliary excitation winding, to ensure that alternating current is continuously and smoothly output to main excitation system.The application is provided with auxiliary excitation winding assembly and magnetic shield, without relying on external power supply, it can independently start excitation process, so that main excitation system does not need additional connection other starting excitation device, and after magnetic field starts, it also does not affect the stability of auxiliary exciter.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of exciter, more particularly to an exciter structure with a function of auxiliary exciter. BACKGROUND

[0002] The exciter is a key equipment for providing excitation current for the rotor of a synchronous machine (such as a synchronous generator or a synchronous motor), and its core function is to control the terminal voltage, reactive power output and operating stability of the motor by adjusting the rotor magnetic field strength, which is a core auxiliary equipment in the fields of power system and industrial driving.

[0003] However, in the prior art, the start of the generator excitation system often relies on an external power supply to provide initial excitation, and an independent start excitation device (such as an auxiliary excitation transformer or an external DC power supply) needs to be additionally configured, resulting in a complex system structure and an increased equipment size. In addition, the initial excitation process needs to be connected through an external line, which not only increases the line loss and fault risk, but also has the problem of start response lag - when the external power supply is interrupted or the start device fails, the excitation system cannot start independently, which seriously affects the reliability of the generator. In addition, some traditional excitation systems do not have a dedicated auxiliary excitation winding assembly, and the three-phase balance of the initial excitation current is difficult to guarantee, which easily leads to excitation output fluctuation and further affects the stable operation of the main excitation system. These defects make the existing excitation system have obvious shortcomings in independence, compactness and anti-interference ability, and it is difficult to meet the needs of scenes with high requirements for start efficiency and operating stability. After starting, the strong magnetic field of the main excitation will interfere with the auxiliary excitation, affecting the stability of the work. In view of this, we propose an exciter structure with a function of auxiliary exciter. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, adapt to the actual needs, and provide an exciter structure with a function of auxiliary exciter to solve the technical problems that the existing technology relies on external devices as initial start devices, the system is prone to fail to start independently, and the auxiliary excitation has insufficient stability.

[0005] To solve the above technical problems, the present application provides the following technical scheme: an exciter structure with a function of auxiliary exciter, comprising a stator and a rotor designed inside the stator.

[0006] A plurality of main excitation stator windings are embedded in the equidistant annular inside of the stator, and a plurality of permanent magnets are embedded in the equidistant annular inside of the front end of the stator.

[0007] A plurality of main excitation rotor windings are wound on the equidistant annular outside of the rotor, a rotary rectifier is installed at the tail end of the rotor, and the output end of the rotary rectifier is connected with a plurality of main excitation rotor windings, a cavity is provided at the head end of the rotor, and an auxiliary excitation winding assembly is provided in the cavity.

[0008] The auxiliary excitation winding assembly comprises a plurality of auxiliary excitation rotor windings connected to the input end of the rotating rectifier;

[0009] The main excitation rotor winding is used to generate a rotating main magnetic field after being supplied with direct current, cutting the main excitation stator winding to generate excitation current for the main generator;

[0010] The auxiliary excitation rotor winding is used to cut the magnetic field of the permanent magnet when rotating to generate initial alternating current into the rotating rectifier;

[0011] The rotating rectifier is used to convert alternating current into direct current and supply the main excitation rotor winding with the direct current;

[0012] The auxiliary excitation rotor winding is connected with a magnetic shield, and the magnetic shield is arranged in the cavity. The head end of the magnetic shield extends to the outside of the cavity, and the head end of the magnetic shield is located in the same horizontal plane as the permanent magnet. A plurality of hollow flow guide structures are arranged equidistantly on the outer wall of the head end of the magnetic shield.

[0013] Preferably, the plurality of main excitation stator windings are connected in any one of a triangle or a star, and the plurality of auxiliary excitation rotor windings are connected in a star.

[0014] Preferably, the polarities of adjacent permanent magnets are alternately arranged, and the plurality of permanent magnets are located in the non-main excitation stator winding region of the stator.

[0015] Preferably, the magnetic shield comprises an outer layer in contact with the main excitation stator winding, a middle layer, and an inner layer close to the auxiliary excitation rotor winding. The outer layer is used to attenuate the strong magnetic field generated by the main excitation rotor winding. The middle layer is used to absorb the residual magnetic field passing through the outer layer. The inner layer is used to enable the weak signal of the permanent magnet magnetic field to smoothly penetrate along the low-magnetic-resistance path of the inner layer and reach the auxiliary excitation rotor winding.

[0016] Preferably, the middle layer is divided into an outer segment, a middle segment, and an inner segment. The thicknesses of the outer segment, the middle segment, and the inner segment are the same. The magnetic permeability μ of the outer segment, the middle segment, and the inner segment gradually increases between 1.05 and 1.15.

[0017] Preferably, a deformation layer is installed between the outer layer and the middle layer. The deformation layer is made of a magnetically sensitive shape memory alloy. The deformation layer has an initial state and a deformed state. The initial state is a circular ring, and the deformed state is a hexagonal structure with each edge concave inward in the middle. The deformation layer is used to enter the deformed state from the initial state after being excited by a magnetic field, thereby generating directional contraction, driving the outer layer to deform slightly inward, reducing the gap between the outer layer and the middle layer, and increasing the penetration resistance of the strong magnetic field. At the same time, the small wrinkles generated by the contraction scatter the strong magnetic field lines, further reducing the penetration rate.

[0018] Preferably, the hollow flow guide structure comprises flow guide windows corresponding to the positions of the permanent magnets and a magnetic field flow guide layer, the flow guide windows are in the shape of a sector, and a resin layer is arranged in the flow guide windows.

[0019] Preferably, the inner wall of the tail end of the magnetic shield is provided with a spiral flow guide structure, the spiral flow guide structure comprises spiral flow guide grooves arranged below the flow guide windows and non-magnetic magnetically conductive paste arranged in the spiral flow guide grooves, and the magnetic permeability of the non-magnetic magnetically conductive paste is between mu1.1 and 1.15.

[0020] Compared with the prior art, the application has the following beneficial effects:

[0021] 1. The auxiliary excitation winding assembly is arranged, the auxiliary excitation rotor winding and the permanent magnet form an initial excitation unit, the adjacent permanent magnets are arranged alternately in opposite polarities to generate a stable magnetic field, when the rotor rotates, the auxiliary excitation rotor winding cuts the magnetic field to generate initial alternating current, the alternating current of the auxiliary excitation rotor winding is converted into direct current by the rotary rectifier, and then the direct current is directly input into the main excitation rotor winding to provide a continuous excitation current for the main excitation rotor winding, thereby forming a closed-loop cooperative mechanism of "auxiliary excitation power generation-rectification-main excitation excitation", after starting, the magnetic shield prevents the main excitation strong magnetic field from affecting the auxiliary excitation winding, and ensures that alternating current is continuously and stably output to the main excitation system. The auxiliary excitation winding assembly and the magnetic shield are arranged, so that the excitation process can be started autonomously without relying on an external power supply, the main excitation system does not need to be additionally connected to other starting excitation devices, and the stability of the auxiliary excitation machine is not affected after the magnetic field is started.

[0022] 2. The magnetic shield with the three-layer composite structure can effectively attenuate the strong magnetic field generated by the main excitation rotor winding, and prevent the strong magnetic field from diffusing to the auxiliary excitation area; the middle layer can layer by layer absorb the residual magnetic field penetrating the outer layer, and avoid interfering with the auxiliary excitation winding; and the inner layer forms a low-magnetic-resistance path, thereby ensuring that the weak magnetic field of the permanent magnet penetrates to the auxiliary excitation rotor winding smoothly, and when the outer layer and the middle layer are stimulated by an external strong magnetic field, the deformation layer between the outer layer and the middle layer shrinks, drives the outer layer to deform inward, reduces the gap between the outer layer and the middle layer, and increases the penetration resistance of the strong magnetic field. The three-layer structure and the deformation structure: the outer layer intercepts the strong magnetic field, the middle layer eliminates residual interference, and the inner layer ensures effective magnetic field transmission, and when the deformation structure is stimulated by a strong magnetic field, the penetration resistance can increase with the increase of the magnetic field in a certain range, thereby avoiding the interference of the main excitation strong magnetic field on the auxiliary excitation, ensuring that the weak magnetic field required by the auxiliary excitation reaches stably, and significantly improving the operation stability of the excitation system.

[0023] 3、The hollow flow guide structure of the head end of the magnetic shield, the forty fan-shaped flow guide windows correspond to the positions of the permanent magnets one by one, align with the magnetic field source, and ensure that the magnetic field generated by the permanent magnet can act on the area of the auxiliary excitation rotor winding; the fan-shaped structure adapts to the magnetic field diffusion characteristics, expands the magnetic field receiving area while reducing the edge loss, the resin layer in the flow guide window is a non-magnetic material, which can avoid shielding or distortion of the magnetic field, and ensure that the magnetic field is transmitted according to the natural path; the embedded aluminum foil magnetic field flow guide layer utilizes the high conductivity and low magnetic resistance characteristics of aluminum to direct the dispersed magnetic field lines to the auxiliary excitation rotor winding, and strengthens the magnetic field cutting strength. The hollow flow guide structure of the present application reduces the loss of the permanent magnet magnetic field when penetrating the magnetic shield, and the initial current induced by the auxiliary excitation winding is more stable, providing more reliable input for the rotary rectifier.

[0024] 4、The spiral flow guide structure of the inner wall of the tail end of the magnetic shield, the non-magnetic magnetic conductive paste filled in the spiral flow guide groove, the spiral structure located below the flow guide window can receive the permanent magnet magnetic field introduced from the upper flow guide window, and the path design of the spiral flow guide groove prolongs the magnetic field action distance, while the non-magnetic magnetic conductive paste can stabilize the magnetic field distribution and reduce the scattering loss of the magnetic field in the transmission process. The spiral flow guide structure of the present application makes the magnetic field entering through the head end flow guide window flow in an orderly manner along the spiral path, and more uniformly acts on the auxiliary excitation rotor winding, cooperates with the rotary cutting action, and makes the initial alternating current output more stable. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the present application;

[0026] Figure 2 It is a structural schematic diagram of the stator of the present application;

[0027] Figure 3 It is a structural schematic diagram of the rotor and auxiliary excitation winding assembly of the present application;

[0028] Figure 4 It is a structural schematic diagram of the rotor of the present application;

[0029] Figure 5 It is a structural schematic diagram of the bottom of the rotor of the present application;

[0030] Figure 6 It is a structural schematic diagram of the auxiliary excitation winding assembly of the present application;

[0031] Figure 7 It is a structural schematic diagram of the auxiliary excitation winding assembly of the present application;

[0032] Figure 8 It is a structural schematic diagram of the internal structure of the magnetic shield of the present application;

[0033] Figure 9 It is a structural schematic diagram of the magnetic field flow guide layer of the present application;

[0034] Figure 10 Structure diagram of the magnetic shield of the application;

[0035] Figure 11 Structure diagram of the initial state of the deformation layer of the application;

[0036] Figure 12 Structure diagram of the deformed state of the deformation layer of the application.

[0037] Explanation of the reference numerals in the drawings:

[0038] 1, stator; 2, rotor; 3, auxiliary excitation winding assembly;

[0039] 101, main excitation stator winding; 102, permanent magnet;

[0040] 201, main excitation rotor winding; 202, rotating rectifier; 203, cavity;

[0041] 301, auxiliary excitation rotor winding; 302, magnetic shield; 303, hollow flow guide structure; 304, spiral flow guide structure;

[0042] 3021, outer layer; 3022, middle layer; 3023, inner layer; 3024, deformation layer;

[0043] 3031, flow guide window; 3032, magnetic field flow guide layer;

[0044] 3041, spiral flow guide groove; 3042, non-magnetic magnetic conductive paste. DETAILED DESCRIPTION

[0045] Example 1, as Figures 1 to 7As shown, the application relates to a structure of an exciter with a function of a sub-excitation exciter, which comprises a stator 1 and a rotor 2 designed in the inside of the stator 1; ten main excitation stator windings 101 are embedded in the inside of the stator 1 in equidistant annular shape, and ten permanent magnets 102 are embedded in the inside of the front end of the stator 1 in equidistant annular shape; six main excitation rotor windings 201 are wound on the outside of the rotor 2 in equidistant annular shape, a rotary rectifier 202 is installed at the tail end of the rotor 2, the output end of the rotary rectifier 202 is connected with the six main excitation rotor windings 201, a cavity 203 is arranged at the head end of the rotor 2, and a sub-excitation winding assembly 3 is arranged in the cavity 203; the sub-excitation winding assembly 3 comprises three sub-excitation rotor windings 301, and the three sub-excitation rotor windings 301 are connected to the input end of the rotary rectifier 202; the main excitation rotor windings 201 are used to generate a rotating main magnetic field after being supplied with direct current, cut the main excitation stator windings 101 to generate excitation current for supplying a main generator; the sub-excitation rotor windings 301 are used to cut the magnetic field of the permanent magnets 102 when rotating to generate initial alternating current into the rotary rectifier 202; and the rotary rectifier 202 is used to convert alternating current into direct current and supply the main excitation rotor windings 201.

[0046] The ten main excitation stator windings 101 are connected in any one of a triangle or a star shape, and the three sub-excitation rotor windings 301 are connected in a star shape.

[0047] The main excitation stator windings 101 are made of enameled copper wire, the main excitation rotor windings 201 are made of thin enameled wire, and the sub-excitation rotor windings 301 are made of thick flat copper wire.

[0048] The polarities of adjacent permanent magnets 102 are alternately arranged, and the ten permanent magnets 102 are all located in the non-main excitation stator winding 101 region of the stator 1.

[0049] The sub-excitation rotor windings 301 are connected with a magnetic shield 302, the magnetic shield 302 is arranged in the cavity 203, the head end of the magnetic shield 302 extends to the outside of the cavity 203, the head end of the magnetic shield 302 is located in the same horizontal plane as the permanent magnet 102, and a plurality of hollow flow guide structures are arranged on the outer wall of the head end of the magnetic shield in equidistant annular shape.

[0050] The sub-excitation rotor windings 301 cut the magnetic field generated by the permanent magnets 102 when rotating, according to the electromagnetic induction law, a closed conductor generates an induced electromotive force when cutting a magnetic induction line in a magnetic field, and generates initial alternating current. The polarities of adjacent permanent magnets are alternately arranged to ensure that the direction of the magnetic field changes periodically, so that the induced current presents three-phase alternating characteristics; the sub-excitation rotor windings are connected in a star shape, and the neutral line of the star-shaped connection is used to offset the zero sequence component in the balanced action of the three-phase current, so as to ensure the stability of the initial alternating current.

[0051] When the main excitation rotor winding 201 is connected to a direct current, a magnetic field is generated around the current according to Ampere's law, the magnetic field strength is proportional to the current, and a rotating main magnetic field is generated; the magnetic field cuts the main excitation stator winding 101, and excitation current for the main generator is generated again through electromagnetic induction, forming a closed loop of "auxiliary excitation power generation rectification main excitation excitation output current", and the essence is multiple conversion and transmission of electromagnetic energy.

[0052] The head end of the magnetic shield extends to the outside of the cavity 203 and is located at the same horizontal plane as the permanent magnet 102, so that the magnetic field of the permanent magnet can directly act on the auxiliary excitation area covered by the magnetic shield, and the magnetic field loss caused by spatial misalignment is avoided.

[0053] The auxiliary excitation winding assembly 3 is provided, the auxiliary excitation rotor winding 301 and the permanent magnet 102 form an initial excitation unit, the adjacent permanent magnets 102 are alternately arranged to generate a stable magnetic field, when the rotor 2 rotates, the auxiliary excitation rotor winding 301 cuts the magnetic field to generate an initial alternating current, and the excitation process can be started independently without relying on an external power supply, and the alternating current of the auxiliary excitation rotor winding 301 is converted into direct current by the rotating rectifier 202, and then directly input into the main excitation rotor winding 201 to provide continuous excitation current for the latter, forming a closed loop cooperation mechanism of "auxiliary excitation power generation rectification main excitation excitation", so that the main excitation system does not need an additional starting excitation device, after starting, the magnetic shield 302 prevents the strong magnetic field of the main excitation from affecting the auxiliary excitation winding, and ensures that the alternating current is continuously and stably output to the main excitation system. The auxiliary excitation winding assembly 3 and the magnetic shield 302 are provided, the excitation process can be started independently without relying on an external power supply, the main excitation system does not need to be connected to other starting excitation devices, and the stability of the auxiliary excitation machine is not affected after the magnetic field is started.

[0054] It is worth noting that, as shown in Figures 10 to 12 The magnetic shield 302 includes an outer layer 3021 in contact with the main excitation stator winding 101, a middle layer 3022 and an inner layer 3023 close to the auxiliary excitation rotor winding 301, the outer layer 3021 is made of stainless steel material, and the magnetic permeability μ of the outer layer 3021 is between 1.02-1.05, the outer layer 3021 is used to attenuate the strong magnetic field generated by the main excitation rotor winding 201, the middle layer 3022 is made of stainless steel and nickel-based alloy powder, the middle layer 3022 is used to absorb the residual magnetic field passing through the outer layer 3021, and the inner layer 3023 is made of nickel-based alloy and epoxy resin coating, the inner layer 3023 is used to make the weak signal of the magnetic field of the permanent magnet 102 penetrate along the low magnetic resistance path of the inner layer 3023 smoothly, and reach the auxiliary excitation rotor winding 301.

[0055] The middle layer 3022 is divided into an outer section, a middle section and an inner section, the thicknesses of the outer section, the middle section and the inner section are the same, the proportions of the nickel-based alloy powder in the outer section, the middle section and the inner section gradually increase, and the magnetic permeability mu of the outer section, the middle section and the inner section gradually increases between 1.05-1.15.

[0056] The proportion of the nickel-based alloy body in the inner layer 3023 is 90%-95%, and the magnetic permeability mu is between 1.2-1.25, and the proportion of the epoxy resin coating is 5%-10%, and the epoxy resin coating is coated on the inner surface of the nickel-based alloy.

[0057] The deformed layer 3024 is installed between the outer layer 3021 and the middle layer 3022, the deformed layer 3024 is made of a magnetic sensitive shape memory alloy, the deformed layer 3024 has an initial state and a deformed state, the initial state is a circular ring, the deformed state is a hexagonal structure, and the middle of each side is concave inward, the deformed layer 3024 is used to enter the deformed state from the initial state after being excited by a magnetic field, thereby generating directional contraction, driving the outer layer to deform inward, reducing the gap between the outer layer 3021 and the middle layer 3022, and increasing the penetration resistance of the strong magnetic field; at the same time, the small wrinkles generated by the contraction scatter the strong magnetic field lines, further reducing the penetration rate.

[0058] When the deformed layer 3024 contracts, it will drive the outer layer 3021 to deform inward, reducing the gap between the outer layer 3021 and the middle layer 3022. According to the principle of magnetic resistance, when the magnetic field penetrates the material, the magnetic permeability of the gap air or non-magnetic medium is much lower than that of the solid material, and the reduction of the gap means that the proportion of the low magnetic permeability region in the magnetic field penetration path is reduced, and the overall magnetic resistance is increased, thereby significantly improving the penetration resistance of the strong magnetic field and weakening the propagation of the strong magnetic field to the auxiliary excitation area.

[0059] The small wrinkles generated by the contraction of the deformed layer 3024 will form a non-uniform structure on the surface of the outer layer. When the strong magnetic field lines contact the non-uniform surface, scattering, reflection and other phenomena occur, similar to the diffuse reflection of light on a rough surface, resulting in disorder of the propagation direction of the magnetic field lines, energy is dispersed and consumed, further reducing the penetration rate of the strong magnetic field.

[0060] The application can effectively attenuate the strong magnetic field generated by the main excitation rotor winding 201 through the three-layer composite magnetic shield 302, prevent it from spreading to the auxiliary excitation area, and can layer by layer absorb the remaining magnetic field penetrating the outer layer 3021 to avoid interference with the auxiliary excitation winding. The inner layer 3023 forms a low magnetic resistance path to ensure that the weak magnetic field of the permanent magnet 102 penetrates to the auxiliary excitation rotor winding 301 smoothly. When the outer layer 3021 and the middle layer 3022 are stimulated by the external strong magnetic field, the deformation layer 3024 between the outer layer 3021 and the middle layer 3022 shrinks, drives the outer layer 3021 to deform inward, reduces the gap between the outer layer 3021 and the middle layer 3022, and increases the penetration resistance of the strong magnetic field. The three-layer structure and the deformation structure of the application can intercept the strong magnetic field, eliminate residual interference, and ensure effective magnetic field transmission. When the strong magnetic field is stimulated, the deformation structure shrinks, the penetration resistance increases with the increase of the magnetic field in a certain range, which avoids the interference of the main excitation strong magnetic field on the auxiliary excitation and ensures the stable arrival of the weak magnetic field required by the auxiliary excitation, and significantly improves the operation stability of the excitation system.

[0061] Further, as shown in Figures 6 to 9 The hollow flow guide structure 303 includes a flow guide window 3031 and a magnetic field flow guide layer 3032. Forty flow guide windows 3031 correspond to the positions of ten permanent magnets 102. The flow guide window 3031 is a fan-shaped structure, and a glass fiber reinforced epoxy resin layer is arranged in the flow guide window 3031. The glass fiber reinforced epoxy resin layer is a non-magnetic material, and the magnetic field flow guide layer 3032 is embedded on the glass fiber reinforced epoxy resin layer, and the magnetic field flow guide layer 3032 is made of aluminum foil.

[0062] The hollow flow guide structure 303 can effectively prevent the strong magnetic field of the main excitation system from passing through while allowing the weak magnetic field of the permanent magnet to pass through. The core reason lies in the synergistic effect of the spatial alignment design and the overall magnetic shielding system, which is as follows:

[0063] The flow guide window 3031 of the hollow flow guide structure corresponds to the position of the permanent magnet 102 at the front end of the stator one by one, and the permanent magnet 102 is located in the non-main excitation stator winding area of the stator. The strong magnetic field of the main excitation system is mainly generated by the main excitation rotor winding 201, and its action area is concentrated in the main body area inside the stator where the main excitation stator winding 101 is located, which is separated from the non-main excitation area where the permanent magnet 102 is located in space. Therefore, the main propagation path of the strong magnetic field is not aligned with the flow guide window, which reduces the possibility of the strong magnetic field passing through the flow guide window from the source.

[0064] The outer layer 3021 and the middle layer 3022 of the magnetic shield are the core structures for blocking strong magnetic fields: the outer layer 3021 attenuates strong magnetic fields through the low magnetic permeability characteristic μ1.02-1.05, and the middle layer 3022 absorbs the remaining strong magnetic fields that penetrate the outer layer 3021 through the magnetic permeability increasing design μ1.05-1.15. Even if the window has no solid magnetic shielding material, the strong magnetic field has been greatly weakened by the two layers of structure before penetrating the outer layer 3021 and the middle layer 3022 to reach the window, and the residual strength is extremely low, making it difficult to effectively transmit to the auxiliary excitation rotor winding 301 through the window.

[0065] The magnetic field guide layer 3032 in the guide window uses low magnetic resistance characteristics to direct and guide the weak magnetic field generated by the permanent magnet to the auxiliary excitation rotor winding, reducing the loss of the weak magnetic field at the window; and for the small amount of residual strong magnetic field that may reach the window, due to the lack of directional guidance, the strong magnetic field is distributed randomly and is different from the directivity of the weak magnetic field, which will cause scattering loss due to the window edge effect, further reducing its ability to penetrate to the auxiliary excitation area.

[0066] The hollow guide structure 303 at the head end of the magnetic shield 302 has forty fan-shaped guide windows 3031 corresponding to the positions of the permanent magnets 102, aligning with the magnetic field source, ensuring that the magnetic field generated by the permanent magnets 102 can concentrate on the auxiliary excitation rotor winding 301 area; the fan-shaped structure adapts to the magnetic field diffusion characteristics, expanding the magnetic field receiving area while reducing edge loss, the resin layer in the guide window 3031 is a non-magnetic material, which can avoid shielding or distortion of the magnetic field, and ensure that the magnetic field is transmitted along the natural path; the aluminum foil magnetic field guide layer 3032 embedded therein uses the high electrical conductivity and low magnetic resistance characteristics of aluminum to direct and guide the dispersed magnetic field lines to the auxiliary excitation rotor winding 301, strengthening the magnetic field cutting strength. The hollow guide structure 303 of the present application reduces the loss of the magnetic field of the permanent magnet 102 when penetrating the magnetic shield 302, and the initial current induced by the auxiliary excitation winding is more stable, providing more reliable input for the rotary rectifier 202.

[0067] Further, as shown in Figures 7 to 8 The tail end inner wall of the magnetic shield 302 is provided with a spiral guide structure 304, which includes a spiral guide groove 3041 and a non-magnetic magnetic paste 3042. The spiral guide groove 3041 is arranged below the guide window 3031, and the non-magnetic magnetic paste 3042 is arranged in the spiral guide groove 3041. The non-magnetic magnetic paste 3042 is made of 85%-90% epoxy resin and 10%-15% ferrite powder, and the magnetic permeability of the non-magnetic magnetic paste 3042 is between μ1.1-1.15.

[0068] The application is filled with non-magnetic magnetic paste 3042 in the spiral flow guide groove 3041, and the spiral structure below the flow guide window 3031 can receive the magnetic field of the permanent magnet 102 introduced from the upper flow guide window 3031, and the path design of the spiral flow guide groove 3041 prolongs the magnetic field action distance, and the non-magnetic magnetic paste 3042 can stabilize the magnetic field distribution and reduce the scattering loss of the magnetic field in the transmission process. The application makes the magnetic field entering through the head end flow guide window 3031 flow along the spiral path in an orderly manner, more uniformly acts on the auxiliary excitation rotor winding 301, cooperates with the rotating cutting action, and makes the initial alternating current output more stable.

[0069] The application discloses the preferred embodiment, but is not limited to this, and the person skilled in the art can easily understand the spirit of the application according to the above-mentioned embodiment, and make different inferences and changes, as long as not departing from the spirit of the application, all within the protection scope of the application.

Claims

1. An exciter structure that also functions as a secondary exciter, characterized in that, It comprises a stator (1) and a rotor (2) designed inside the stator (1); The inner equidistant annular of the stator (1) is embedded with a plurality of main excitation stator windings (101), and the inner equidistant annular of the front end of the stator (1) is embedded with a plurality of permanent magnets (102); The outer equidistant annular of the rotor (2) is wound with a plurality of main excitation rotor windings (201), the tail end of the rotor (2) is provided with a rotating rectifier (202), and the output end of the rotating rectifier (202) is connected with a plurality of main excitation rotor windings (201), and the head end of the rotor (2) is provided with a cavity (203), and the cavity (203) is provided with a secondary excitation winding assembly (3); The secondary excitation winding assembly (3) comprises a plurality of secondary excitation rotor windings (301), and a plurality of secondary excitation rotor windings (301) are connected to the input end of the rotating rectifier (202); The secondary excitation rotor winding (301) is connected with a magnetic shield (302), and the magnetic shield (302) is arranged in the cavity (203), the head end of the magnetic shield (302) extends to the outside of the cavity (203), and the head end of the magnetic shield (302) is located in the same horizontal plane with the permanent magnet (102), a plurality of hollow flow guide structures (303) are arranged in the equidistant annular of the outer wall of the head end of the magnetic shield (302), and the hollow flow guide structures (303) are used to enable the weak magnetic field to pass through and block the strong magnetic field; The polarities of adjacent permanent magnets (102) are alternately arranged, and a plurality of permanent magnets (102) are located in the non-main excitation stator winding (101) region of the stator (1); The magnetic shield (302) comprises an outer layer (3021) in contact with the main excitation stator winding (101), a middle layer (3022) and an inner layer (3023) close to the secondary excitation rotor winding (301), the outer layer (3021) is used to attenuate the strong magnetic field generated by the main excitation rotor winding (201), the middle layer (3022) is used to absorb the remaining magnetic field passing through the outer layer (3021), and the inner layer (3023) is used to enable the weak signal of the permanent magnet (102) magnetic field to smoothly penetrate along the low magnetic resistance path of the inner layer (3023) and reach the secondary excitation rotor winding (301).

2. The exciter structure having a function of a sub-exciter according to claim 1, characterized by A plurality of main excitation stator windings (101) are connected in any one of a triangle or a star, and a plurality of secondary excitation rotor windings (301) are connected in a star.

3. The exciter structure having a function of a sub-exciter according to claim 1, characterized by The middle layer (3022) is divided into an outer section, a middle section and an inner section, the thicknesses of the outer section, the middle section and the inner section are the same, and the magnetic permeability μ of the outer section, the middle section and the inner section gradually increases between 1.05-1.

15.

4. The exciter structure having a function of a sub-exciter according to claim 1, characterized by The deforming layer (3024) is made of magnetic sensitive shape memory alloy, has an initial state and a deformed state, the initial state is a circular ring, the deformed state is a hexagonal structure, and the middle part of each side is inwardly recessed, the deforming layer (3024) is used for entering the deformed state from the initial state after being excited by a magnetic field, thereby generating directional contraction, driving the outer layer to be slightly deformed inward, reducing the gap between the outer layer (3021) and the middle layer (3022), and increasing the penetration resistance of the strong magnetic field; meanwhile, the small wrinkles generated by the contraction scatter the strong magnetic field lines, and the penetration rate is further reduced.

5. The exciter structure having a function of a sub-exciter according to claim 1, characterized by The hollow flow guide structure (303) comprises flow guide windows (3031) and a magnetic field flow guide layer (3032), a plurality of flow guide windows (3031) correspond to positions of the plurality of permanent magnets (102), the flow guide windows (3031) are in a fan-shaped structure, the flow guide windows (3031) are provided with resin layers, and the magnetic field flow guide layer (3032) is embedded on the resin layers.

6. The exciter structure having a function of a sub-exciter according to claim 5, characterized by The tail end inner wall of the magnetic shield (302) is provided with a spiral flow guide structure (304), the spiral flow guide structure (304) comprises spiral flow guide grooves (3041) and non-magnetic magnetic conductive paste (3042), the spiral flow guide grooves (3041) are arranged below the flow guide windows (3031), the non-magnetic magnetic conductive paste (3042) is arranged in the spiral flow guide grooves (3041), and the magnetic permeability of the non-magnetic magnetic conductive paste (3042) is between μ1.1-1.15.

Images