Damping type linear generator, design method and damping control method

Abstract

The application provides a damping type linear generator, a design method and a damping control method, and belongs to the field of rail transit. The damping type linear generator comprises a superconducting coil, an 8-shaped coil and a damping type current collection coil. The damping type current collection coil is arranged in the superconducting coil shell on both sides of the superconducting motorized magnetic suspension train bogie, is used for collecting the energy of the air gap harmonic magnetic field of the 8-shaped coil, and directly supplies power to the on-board electrical equipment and the battery after rectification and filtering, and generates electricity by using the harmonic magnetic field in the train system. The damping type current collection coil is also used for receiving the stable current injected from the on-board power converter converted from the battery. At this time, the damping type current collection coil simulates the superconducting coil magnetic field to generate additional electromagnetic damping force, so as to reduce the vibration amplitude of the bogie in high-speed operation and improve the stability of the superconducting motorized magnetic suspension train in operation. The application improves the stability of the bogie in the operation of the magnetic suspension train.

Description

Technical Field

[0001] This invention belongs to the field of rail transit, specifically relating to a damped linear generator, its design method, and its damping control method. Background Technology

[0002] Superconducting electric maglev trains operate at stable speeds exceeding 500 km / h. When the train is levitated, using a pantograph for power supply increases the probability of electrical grid fires due to frictional heat generation, and also poses risks such as wire breaks and pantograph damage. Furthermore, foreign objects frequently dangle from the overhead contact lines due to weather conditions, causing train shutdowns. Therefore, superconducting electric maglev trains generally employ contactless power supply methods, such as harmonic linear generators.

[0003] In existing technologies, when harmonic linear generators are used to power superconducting electric maglev trains, the inherent damping of the superconducting electric maglev at high speeds is very small. Current perturbations and uneven air gaps caused by the bending deformation of the track bridge make the vehicle prone to bumps and vibrations during operation, affecting passenger comfort. Furthermore, superconducting electric maglev trains experience various complex operating conditions during operation, such as… Figure 1 As shown, there are five non-stationary operating conditions caused by translation and rotation along the x-axis of the running direction, the y-axis of the guiding direction, and the z-axis of the suspension direction: lateral offset, suspension vibration, lateral roll, yaw, and pitch. Although the vibration amplitude can be reduced by adding a secondary damping device between the bogie and the car body, the damping effect is not good when dealing with the complex operating conditions mentioned above, resulting in low passenger comfort. In addition, to achieve the damping effect and improve passenger comfort, it is necessary to design and optimize the structure of the linear generator based on the maglev train. However, since the linear generator is installed on both sides of the bogie and runs synchronously with the superconducting coil, it can only generate electricity using the air gap harmonic magnetic field. The air gap magnetic field is a complex function related to the running speed, time, structural parameters, electrical parameters, and spatial position of the superconducting electric maglev vehicle, the output characteristics of the superconducting coil and the figure-eight coil. Therefore, the structure of the collector coil and the output characteristics of the linear generator are closely related to the harmonics of the air gap magnetic field, making the structural design of the linear generator difficult and limiting the optimization of the structural design to a certain extent. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, the present invention aims to provide a damped linear generator, a design method, and a damping control method. By optimizing the arrangement, position design, and connection of the collector coils in the generator through the damping characteristics of the generator's magnetic field, a damped collector coil and a corresponding damped linear generator are obtained. By controlling the charging and discharging between the battery and the linear generator, the stability of the bogie in the operation of the maglev train is improved, and the ride comfort is enhanced.

[0005] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0006] In a first aspect, embodiments of the present invention provide a damped linear generator, the linear generator comprising a superconducting coil, a figure-eight coil, and a damped current collector coil; wherein...

[0007] The damping current collector coil is installed inside the superconducting coil shell on both sides of the bogie of the superconducting electric maglev train. It is used to collect the energy of the harmonic magnetic field of the air gap of the figure-eight coil and directly power the on-board electrical equipment and battery of the superconducting electric maglev train after rectification and filtering. It generates electricity by utilizing the harmonic magnetic field in the superconducting electric maglev train's own system.

[0008] The damping current collector coil is also used to receive the stable current converted from the on-board battery by the on-board power converter and injected into the damping current collector coil. At this time, the damping current collector coil simulates the magnetic field of the superconducting coil to generate additional electromagnetic damping force, thereby reducing the vibration amplitude of the bogie when running at high speed and improving the stability of the superconducting electric maglev train.

[0009] In a preferred embodiment of the present invention, the arrangement structure of the damped current collector coil is based on the arrangement of the UVW three-phase standard current collector coil. The electrode pitch between the VW phases remains unchanged, and two identical U-phase coils u and u′ are arranged on both sides of the VW phases, ensuring that a set of uVWu′ three-phase current collector coils can still obtain a sine wave. At this time, the adjacent sets of uVWu′ current collector coils, due to the magnetic field of the superconducting range they cover being opposite in direction to the previous set, are connected in reverse to generate a magnetic field opposite to the previous set of damped coils. The electrode pitch between the u and -u, u′ and -u′, V and -V, and W and -W phase current collector coils remains equal to the actual superconducting electrode pitch τ. sx Damped current collector coils can simulate the magnetic field of superconducting coils by injecting stable current, thereby generating additional induced electromotive force in the figure-eight coil and increasing the electromagnetic damping of the system.

[0010] Secondly, embodiments of the present invention also provide a design method for a damped linear generator as described above, the design method comprising the following steps:

[0011] Step S1: Using the spatial harmonic method, the magnetic field of the superconducting coil is decomposed into Fourier components to obtain the y-axis component of the magnetic induction intensity of the superconducting coil.

[0012] Step S2: Using the definitions of magnetic induction intensity, induced electromotive force, and circuit principles, the magnetic induction intensity B of the figure-eight coil is obtained. ey The expression for (x,y,z);

[0013] Step S3: The maximum harmonic order of the air gap magnetic field is 2k-1, derived from the magnetic induction intensity formula of the figure-eight coil.

[0014] Step S4: Install the damped collector coil on the outer shell of the superconducting coil, and keep the fundamental component of the air gap magnetic field and the damped collector coil stationary; place a set of collector coils within two maximum harmonic order periods, and satisfy the predetermined relationship between the pole pitch of the damped collector coil and the pole pitch of the u-phase coil in the damped linear collector coil to obtain the UVW three-phase sine wave.

[0015] Step S5, based on the magnetic induction intensity B of the figure-eight coil ey The magnetic flux density B of the figure-eight coil obtained from the expression (x,y,z) ey The expression for (x,y,z) can be used to obtain the induced electromotive force U of a single damped collector coil using the definition of induced electromotive force. c (x,y,z); Let the expected power output of the linear generator be P. According to the definition of current density, the current density of a single-turn coil is obtained.

[0016] Step S6: Determine the wire type based on the single-turn coil current density, and specify the wire diameter and the number of turns of the UVW three-phase collector coil;

[0017] Step S7: Keep the geometric center point of the collector coil at the same horizontal position as the figure-eight coil.

[0018] In a preferred embodiment of the present invention, the y-axis component B of the magnetic induction intensity of the superconducting coil sy (x,y,z) is:

[0019]

[0020] In equation (1), the series n and m are both odd numbers, δ is the number of superconducting coils, and G s =λC s f s , λ=(k sx 2 +k sz 2 ) 1 / 2 C s =8μ0N s I s / τ x τ z f s =sin(k) sx ·a s / 2)·sin(k sz ·b s / 2) / k sx k sz k sx=nπ / τ x k sz =mπ / τ z Vacuum permeability μ0 = 4π × 10 -7 Wb / (A·m), N s and I s These represent the number of turns of the superconducting coil and the injected current, τ, respectively. x and τ z Let τ be the pole distances of the superconducting coil in the x-axis and y-axis directions, respectively, and let their values ​​satisfy: τ x >>τ sx ;τ z >>b s a s τ represents the equivalent length of the superconducting coil along the x-axis; sx b represents the true pole distance of the superconducting coil along the x-axis. s denoted as the equivalent length of the superconducting coil along the z-axis.

[0021] As a preferred embodiment of the present invention, the magnetic induction intensity B of the figure-eight coil ey The expression for (x,y,z) is:

[0022]

[0023] In equation (2), ε is the number of “8” coils, and P e =4kμ0λN e f e / τ sx τ sz The maximum current I of the εth “8” coil at time t εmax =(-1) δ-1 Z e F e The impedance Z of the figure-eight coil e =jnωN e / (jnωL e +R e ), F e =G e ·[cos(k sz z eB )-cos(k sz z eU )]e -λye G e =4f e G s f e =sin(k) sx ·a e / 2)·sin(k sz ·b e / 2) / k sx ksz ; k is the ratio of the superconducting coil pole pitch to the figure-eight coil pole pitch, and k≠1, N e L represents the number of turns of the figure-eight coil. e and R e These are the self-inductance and resistance of the figure-eight coil, respectively. e and b e These are the equivalent lengths of the figure-eight coil on the x-axis and z-axis, respectively. eU and z eB These represent the z-coordinates of the upper and lower individual figure-eight coils, respectively, on the y-axis. e The coordinates of the figure-eight coil on the y-axis.

[0024] In a preferred embodiment of the present invention, in step S4, the pole spacing τ of the damped collector coil is... cx The following relationship must be satisfied to obtain the UVW three-phase sine wave:

[0025]

[0026] The pole pitch τ of the u-phase coil in a damped linear collector coil cu Satisfy the following formula:

[0027]

[0028] In equation (4), a cv and a cu e represents the equivalent length of the VW phase and uu′ phase coils, respectively. cv and e cu Let e ​​be the cross-sectional length of the VW phase and uu′ phase coils, respectively, and let e be the cross-sectional length of the coils. cv =N cv D c / K c e cu =N c u D c / K c N cv and N cu D represents the number of turns of the VW phase and uu′ phase coils, respectively. c K represents the wire diameter. c is the fill factor of the collector coil.

[0029] In a preferred embodiment of the present invention, the induced electromotive force U of a single damped collector coil in step S5 is... c (x,y,z) is:

[0030]

[0031] In equation (5), G c | 2k-1=128k 2 μ0N c N e ωI εmax | 2k-1 f e | 2k-1 (f cU | 2k-1 -f cB | 2k-1 )λ| 2k-1 / τ sx τ s z k sx | 2k-1 = (2k-1)π / τ sx ,λ| 2k-1 =(k sx | 2k-1 2 +k sz 2 ) 1 / 2 I εmax | 2k-1 =(-1) δ Z e G e | 2k-1 f e | 2k-1 =sin(k) sx | 2k-1 ·a e / 2)sin(k sz ·b e / 2) / k sx | 2k-1 k sz f cU | 2k-1 =sin(k) sx | 2k-1 ·a c / 2)sin(k sz ·b cU / 2) / k sx | 2k-1 k sz f cB | 2k-1 =sink sx | 2k-1 ·a c / 2)sin(k sz ·b cB / 2) / k sx | 2k-1 k sz z cU and z cB Let b be the coordinates of the center points of the upper and lower collector coils on the z-axis. cUand b cB These are the lengths of the upper and lower collector coils along the z-axis, respectively.

[0032] In a preferred embodiment of the present invention, the single-turn coil current density J is:

[0033]

[0034] In equation (6), S is the cross-sectional area of ​​a single collector coil. This refers to the power factor of the power supply line.

[0035] Thirdly, embodiments of the present invention provide a damping control method for a damped linear generator, wherein the method is implemented using a damped linear generator designed as described above;

[0036] First, the damped current collector coil is installed inside the casing of the superconducting coil according to the designed connection method, position design and arrangement structure of the current collector coil, to obtain a damped linear generator;

[0037] Next, perform the following steps:

[0038] Step S21: The damped linear generator uses the harmonic magnetic field of the figure-eight coil to convert AC power into DC power through the rectification stage to power the vehicle-mounted electrical equipment and the battery.

[0039] Step S22: Real-time determination of the battery charge status; when the battery status is determined to be in a discharging state, stop supplying power to the battery and proceed to step S23.

[0040] In step S23, the battery supplies a stable DC current to the damped current collector coil via a converter, thereby generating additional electromagnetic force and enhancing the electromagnetic stiffness of the bogie.

[0041] In a preferred embodiment of the present invention, in step S22, the charging and discharging conditions of the battery are first determined by its state of charge (SOC):

[0042]

[0043] In equation (7), Q r Q represents the remaining battery capacity. rated The battery is at its rated power. The battery's state of charge is related to its terminal voltage V. bat Closely related to the battery's terminal voltage, when the battery's charge level is in the range of 20% to 80%, the change in the battery's terminal voltage is relatively gradual. Judging the battery's charge level helps determine the battery's charging and discharging conditions.

[0044] During battery charging and discharging, firstly, AC power is converted into DC power through rectification and filtering, which can then directly power the vehicle's electrical equipment. Secondly, by collecting the battery's terminal voltage and current, the battery's state of charge is estimated. The terminal voltage V is set according to different battery types. When the battery's state of charge is below 20%, switch S is closed. c Disconnect switch S d The battery enters charging mode; when the battery charge is above 80%, switch S is disconnected. c Close switch S d The battery enters a discharging state.

[0045] The technical solutions provided in the embodiments of the present invention have the following beneficial effects:

[0046] The damped linear generator, design method, and damping control method provided in this invention enable contactless power supply to superconducting electric maglev trains without the need for additional damping devices in existing systems. This effectively enhances the electromagnetic stiffness of the bogie, successfully overcoming the technical challenges of onboard power supply safety and inherent damping deficiencies in superconducting electric maglev trains. By accurately simulating the magnetic field distribution of the superconducting coil and optimizing the current collector coil structure, additional electromagnetic damping force is provided to the bogie, significantly improving the instability that may occur when the vehicle faces complex operating conditions, thereby enhancing the overall system's operational stability. Simultaneously, utilizing the principle of electromagnetic induction, an autonomous power supply function is achieved without relying on external power supply equipment, thus avoiding the technical limitations and bottlenecks of traditional mechanical transmission devices and complex control systems. Furthermore, the method is universally applicable and can be extended to various types of contactless harmonic linear generators, serving as a core component of their damping adjustment systems, demonstrating strong application potential and value.

[0047] Of course, implementing any product or method of the present invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0049] Figure 1 This is a schematic diagram of the superconducting magnetic levitation principle in existing technology;

[0050] Figure 2 This is a schematic diagram of the damped linear generator structure in an embodiment of the present invention;

[0051] Figure 3 This is a schematic diagram of the standard collector coil topology of the high-speed magnetic levitation linear generator in an embodiment of the present invention;

[0052] Figure 4 This is a schematic diagram of the damped collector coil topology of the high-speed magnetic levitation linear generator in an embodiment of the present invention;

[0053] Figure 5 This is a schematic diagram of the standard collector coil topology designed in an embodiment of the present invention;

[0054] Figure 6 This is a schematic diagram of the damped collector coil topology designed in an embodiment of the present invention;

[0055] Figure 7 This is a schematic diagram of the damped collector coil structure design in an embodiment of the present invention;

[0056] Figure 8 This is a schematic diagram of the V-phase damping current collector coil connection structure in an embodiment of the present invention;

[0057] Figure 9 This is a functional schematic diagram of a damped linear generator in an embodiment of the present invention;

[0058] Figure 10 This is a functional schematic diagram of a damped linear generator in an embodiment of the present invention;

[0059] Figure 11 This is the equivalent circuit of the storage battery in the embodiment of the present invention;

[0060] Figure 12 This is a schematic diagram of the battery charging and discharging structure in an embodiment of the present invention. Detailed Implementation

[0061] After discovering the aforementioned problems, the inventors of this application conducted a detailed study of existing harmonic linear generators and related technologies for maglev trains. The study found that integrating a superconducting electric magnetic levitation linear generator into the vehicle's bogie structure not only provides efficient power generation but also utilizes an electromagnetic mechanism that generates a significant damping effect during train operation. This damping effect effectively absorbs and mitigates irregular excitations from the track and vehicle body vibrations under various operating conditions, thereby significantly enhancing the overall rigidity of the vehicle structure. However, optimizing the arrangement of the current collector coils and injecting current into the coils to simulate the magnetic field of the superconducting coils to provide additional damping force requires coordinating the power generation performance of the linear generator with the current-carrying limit of the coils themselves. Furthermore, it is necessary to minimize changes to the airflow width to avoid increasing the risk of collisions between the train and the lateral track walls. This makes the control strategy and structural design optimization of the damped linear generator highly challenging.

[0062] It should be noted that the defects in the above-mentioned prior art solutions are all the result of the inventors' practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed by the embodiments of the present invention in the following text should be the inventors' contributions to the present invention.

[0063] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can also be combined with each other.

[0064] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, the terms "first," "second," "third," "fourth," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0065] After the above in-depth analysis, the embodiments of the present invention provide a damped linear generator, a design method, and a damping control method. By effectively utilizing the inherent electromagnetic damping characteristics of the linear generator, the structural stiffness of the vehicle bogie is significantly enhanced, thereby greatly improving the train's driving stability and ride comfort during high-speed operation. The damped linear generator provides a contactless power supply system for the superconducting electric maglev train and enhances the damping of the train under complex operating conditions. The present invention places damped current collector coils on both sides of the superconducting electric maglev train bogie. On the one hand, by collecting the energy of the harmonic magnetic field of the air gap of the figure-eight coil, after rectification and filtering, it can directly power the on-board electrical equipment and batteries of the superconducting electric maglev train. By using the harmonic magnetic field in the superconducting electric maglev train's own system for power generation, the redundancy of the equipment is greatly reduced, saving economic costs. On the other hand, the battery injects a stable current into the damped current collector coil through a power converter, simulating the magnetic field of the superconducting coil to generate additional electromagnetic damping force, thereby reducing the vibration amplitude of the bogie during high-speed operation and improving the stability of the superconducting electric maglev train during high-speed operation under complex operating conditions. Therefore, this invention, through precise design of the spatial arrangement of the current collector coils, ensures maximum damping efficiency, matching the needs of different vehicle models and operating conditions, and achieving more precise dynamic stability control. Compared to traditional superconducting electric magnetic levitation vehicles, the bogie system of this invention not only significantly improves driving stability but also holds promise for energy recovery and utilization through the power generation function of linear generators, promoting the green and sustainable development of rail transit systems.

[0066] like Figure 2 As shown, the damped linear generator includes a superconducting coil, a figure-eight coil, and a damped collector coil. The damped collector coil is installed inside the superconducting coil housing on both sides of the bogie of the superconducting electric maglev train. It is used to collect the energy of the harmonic magnetic field in the air gap of the figure-eight coil and directly power the on-board electrical equipment and battery of the superconducting electric maglev train after rectification and filtering. It generates electricity by using the harmonic magnetic field in the superconducting electric maglev train's own system, which greatly reduces equipment redundancy and saves costs.

[0067] The damping current collector coil is also used to receive the stable current converted from the vehicle battery by the on-board power converter and injected into the damping current collector coil. At this time, the damping current collector coil simulates the magnetic field of the superconducting coil to generate additional electromagnetic damping force, thereby reducing the vibration amplitude of the bogie when running at high speed and improving the stability of the superconducting electric maglev train, especially the stability when running at high speed under complex conditions.

[0068] In one specific embodiment, the arrangement structure of the damped current collector coil will be as follows: Figure 3The arrangement of the UVW three-phase standard collector coils shown is optimized. In the case of a standard UVW three-phase collector coil arrangement, to ensure the collector coils can obtain a three-phase sine wave for convenient power supply to vehicle-mounted electrical equipment and batteries using a rectifier, the electrode spacing τ of the collector coils is optimized. cx This should be related to the maximum harmonic order of the air gap magnetic field to ensure that the linear generator can output maximum power. Therefore, when optimizing the coil layout, such as... Figure 4 As shown, keeping the polar distance between phases V and W constant is still τ. cx Two identical U-phase coils, u and u′, are arranged on either side of the VW phases, ensuring that a set of uVWu′ three-phase collector coils can still generate a sinusoidal wave. Since the magnetic field of the superconducting range covered by the adjacent uVWu′ collector coils is opposite in direction to the previous set, they are connected in reverse to generate a magnetic field opposite to that of the previous set of collector coils. This maintains the pole pitch between the u and -u, u′ and -u′, V and -V, and W and -W phase collector coils equal to the actual superconducting pole pitch τ. sx Thus, the damped current collector coil can simulate the magnetic field of a superconducting coil by injecting a stable current, thereby generating an additional induced electromotive force in the figure-eight coil and increasing the electromagnetic damping of the system.

[0069] As can be seen from the above, this embodiment optimizes the traditional collector coil into a damped collector coil, rearranges the space of the UVW three-phase coils and changes the connection method in the damped collector coil, so that by injecting current into the coil, it can provide additional electromagnetic damping force from the collector coil to the vehicle bogie without changing the power generation capacity of the collector coil.

[0070] Based on the provided damped linear generator, the present invention also provides a design method for a damped linear generator, the method comprising the following steps:

[0071] Step S1: Using the spatial harmonic method, perform Fourier decomposition on the magnetic field of the superconducting coil to obtain the y-axis component B of the superconducting coil's magnetic induction intensity. sy (x,y,z) is:

[0072]

[0073] In equation (1), the series n and m are both odd numbers, δ is the number of superconducting coils, and G s =λC s f s , λ=(k sx 2 +k sz 2 ) 1 / 2 C s =8μ0N s Is / τ x τ z f s =sin(k) sx ·a s / 2)·sin(k sz ·b s / 2) / k sx k sz k sx =nπ / τ x k sz =mπ / τ z Vacuum permeability μ0 = 4π × 10 -7 Wb / (A·m), N s and I s These represent the number of turns of the superconducting coil and the injected current, τ, respectively. x and τ z Let τ be the pole distances of the superconducting coil in the x-axis and y-axis directions, respectively, and let their values ​​satisfy: τ x >>τ sx (The actual pole distance of the superconducting coil along the x-axis); τ z >>b s (Equivalent length of the superconducting coil on the z-axis), a s Let be the equivalent length of the superconducting coil along the x-axis. Clearly, once the electrical and structural parameters of the superconducting coil are determined, the y-axis component B of the superconducting coil's magnetic flux density... sy It is only related to the spatial location of the sampling point.

[0074] Step S2: Using the definitions of magnetic induction intensity, induced electromotive force, and circuit principles, the magnetic induction intensity B of the figure-eight coil is obtained. ey The expression for (x,y,z) is:

[0075]

[0076] In equation (2), ε is the number of “8” coils, and P e =4kμ0λN e f e / τ sx τ sz The maximum current I of the εth “8” coil at time t εmax =(-1) δ-1 Z e F e The impedance Z of the figure-eight coil e =jnωN e / (jnωL e +R e ), F e =G e ·[cos(ksz z eB )-cos(k sz z eU )]e -λye G e =4f e G s f e =sin(k) sx ·a e / 2)·sin(k sz ·b e / 2) / k sx k sz ; k is the ratio of the superconducting coil pole pitch to the figure-eight coil pole pitch, and k≠1, N e L represents the number of turns of the figure-eight coil. e and R e These are the self-inductance and resistance of the figure-eight coil, respectively. e and b e These are the equivalent lengths of the figure-eight coil on the x-axis and z-axis, respectively. eU and z eB These represent the z-coordinates of the upper and lower individual figure-eight coils, respectively, on the y-axis. e Let be the y-coordinate of the figure-eight coil. Clearly, once the electrical and structural parameters of the figure-eight coil, as well as its positional relationship with the superconducting coil, are determined, the magnetic flux density B of the figure-eight coil is... ey (x,y,z) is only related to the spatial location of the sampling point and the sampling time.

[0077] Step S3: The maximum harmonic order of the air gap magnetic field is 2k-1, derived from the magnetic induction intensity formula of the figure-eight coil.

[0078] Step S4: Install the damped current collector coil on the outer shell of the superconducting coil, keeping the fundamental component of the air gap magnetic field stationary with respect to the damped current collector coil; Figure 5 As shown, a set of collector coils is placed within two maximum harmonic order periods, and the pole pitch τ of the damped collector coils is... cx The following relationship must be satisfied to obtain the UVW three-phase sine wave:

[0079]

[0080] At the same time, such as Figure 6 As shown, the pole pitch τ of the u-phase coil in the damped linear collector coil cu Satisfy the following formula:

[0081]

[0082] In equation (4), a cv and a cue represents the equivalent length of the VW phase and uu′ phase coils, respectively. cv and e cu Let e ​​be the cross-sectional length of the VW phase and uu′ phase coils, respectively, and let e be the cross-sectional length of the coils. cv =N cv D c / K c e cu =N c u D c / K c N cv and N cu D represents the number of turns of the VW phase and uu′ phase coils, respectively. c K represents the wire diameter. c is the fill factor of the collector coil.

[0083] As can be seen from formula (4), the pole pitch τ of phase u coils cu The design of the parameters is closely related to the number of turns of the UVW three-phase collector coil and the selection of conductors.

[0084] Step S5, the magnetic induction intensity B of the figure-eight coil is obtained according to formula (2). ey The expression for (x,y,z) can be used to obtain the induced electromotive force U of a single damped collector coil using the definition of induced electromotive force. c (x,y,z) is:

[0085]

[0086] In equation (5), G c | 2k-1 =128k 2 μ0N c N e ωI εmax | 2k-1 f e | 2k-1 (f cU | 2k-1 -f cB | 2k-1 )λ| 2k-1 / τ sx τ s z k sx | 2k-1 = (2k-1)π / τ sx ,λ| 2k-1 =(k sx | 2k-1 2 +k sz 2 ) 1 / 2 I εmax |2k-1 =(-1) δ Z e G e | 2k-1 f e | 2k-1 =sin(k) sx | 2k-1 ·a e / 2)sin(k sz ·b e / 2) / k sx | 2k-1 k sz f cU | 2k-1 =sin(k) sx | 2k-1 ·a c / 2)sin(k sz ·b cU / 2) / k sx | 2k-1 k sz f cB | 2k-1 =sink sx | 2k-1 ·a c / 2)sin(k sz ·b cB / 2) / k sx | 2k-1 k sz z cU and z cB Let b be the coordinates of the center points of the upper and lower collector coils on the z-axis. cU and b cB Let be the lengths of the upper and lower collector coils along the z-axis, respectively. Assuming the expected power output of the linear generator is P, then according to the definition of current density, the current density J of a single-turn coil can be obtained as:

[0087]

[0088] In equation (6), S is the cross-sectional area of ​​a single collector coil. This refers to the power factor of the power supply line.

[0089] Step S6: According to formula (6), the wire type can be determined, and then the wire diameter and the number of turns of the UVW three-phase collector coil can be determined.

[0090] Step S7, as follows Figure 7 As shown, the geometric center of the collector coil is kept at the same horizontal position as the figure-eight coil.

[0091] In this step, it can also be seen from formula (5) that the magnitude of the induced electromotive force of a single collector coil is related to the coordinates and lengths of the center points of the upper and lower collector coils along the z-axis, because the induced electromotive force of the collector coil is generated by cutting the air gap magnetic field. Therefore, on the one hand, the lengths b of the upper and lower collector coils along the z-axis... cU and b cB The magnetic induction intensity of the figure-eight coil should be determined by calculating formula (2). On the other hand, the height of the superconducting shell should also be considered to make the best use of the coverage of the magnetic field of the figure-eight coil, while not affecting the mechanical installation of the superconducting shell.

[0092] In a specific application example, the damped collector coil can further improve the power generation capacity of the linear generator through structural improvements and optimizations. Preferably, since the magnetic fields of the upper and lower coils of the figure-eight coil are in opposite directions, the collector coil should also be designed as a figure-eight structure with the upper and lower coils reversed to improve the power generation capacity of the linear generator. Furthermore, since the magnetic fields of the left and right sides of the figure-eight coils are also in opposite directions, in order to improve the ability to cope with complex operating conditions, such as… Figure 8 As shown, taking the V-phase coil as an example, the damping type collector coil should be a structure in which the upper and lower coils on the left and right sides are connected in opposite directions. This connection method will not change the power generation capacity of the collector coil, and at the same time, it can enhance the electromagnetic force of the bogie according to the transformation characteristics of the magnetic field.

[0093] Based on the designed damping current collector coil, this embodiment of the invention also provides a damping control method for a damped linear generator. The method is implemented using the designed damping current collector coil. First, the damping current collector coil is installed inside the casing of the superconducting coil according to the designed connection method, position design, and arrangement structure, thus obtaining a damped linear generator; secondly, as... Figure 9 As shown, perform the following steps:

[0094] Step S21: The damped linear generator uses the harmonic magnetic field of the figure-eight coil to convert AC power into DC power through the rectification stage to power the vehicle's electrical equipment and the battery.

[0095] Step S22: Real-time determination of the battery charge status; when the battery status is determined to be in a discharge state, stop supplying power to the battery and proceed to step S23.

[0096] In this step, to fully utilize the linear generator's power generation and damping functions, the control circuit should be able to switch the linear generator's operating state in a timely manner. Different operating states of the linear generator correspond to the charging or discharging states of the battery. The first step in determining the battery's charging and discharging status is to assess its State of Charge (SOC), i.e.:

[0097]

[0098] In equation (7), Q r Q represents the remaining battery capacity. rated The battery is at its rated power. The battery's state of charge is related to its terminal voltage V. bat Closely related, such as Figure 10 As shown, the battery terminal voltage changes to some extent with the battery state of charge. When the state of charge is in the range of 20% to 80%, the change in battery terminal voltage is relatively gradual. This indicates that the battery's operating characteristics are relatively stable within this range. By utilizing this characteristic of the battery, the battery state of charge can be determined, thereby determining the battery's charging and discharging conditions.

[0099] The battery is charged and discharged using the constant current method. Compared to the constant voltage method, the constant current method charges faster, but overcharging can occur later due to the rise in battery voltage. Therefore, the switching of charging states should be consistent with the changes in battery terminal voltage to avoid damage to the battery due to overcharging. Figure 11 As shown, an equivalent circuit model of the battery is established. When constant current charging and discharging is performed, the battery's electric current E... p It can be represented as:

[0100]

[0101] In equation (8), I p R is the charging and discharging current. p R is the ohmic resistor of the battery. d R is the diffusion resistance. k For dynamic resistance, τ d =R d C d , τ k =R k C k As mentioned earlier, the battery's state of charge (SOC) and terminal voltage V... bat Related, when the charging and discharging current I p At a certain time, through the battery-powered E p The detection can reflect changes in the battery's charge state, thereby altering the battery's charging and discharging conditions.

[0102] The structure and principle of the battery charging and discharging system are as follows: Figure 12 As shown, taking the U-phase collector coil as an example, firstly, the AC power is converted into DC power through rectification and filtering, which can then directly power the vehicle's electrical equipment. Secondly, by collecting the battery's terminal voltage and current, the battery's state of charge is estimated using formula (8), and the settings are adjusted according to different battery types. Figure 10 The terminal voltage V shown indicates that when the battery's charge level is below 20%, switch S is closed. cDisconnect switch S d The battery enters charging mode. When the battery charge is above 80%, switch S is disconnected. c Close switch S d The battery enters a discharging state.

[0103] In step S23, the battery supplies a stable DC current to the damped current collector coil via a converter, thereby generating additional electromagnetic force and enhancing the electromagnetic stiffness of the bogie.

[0104] As can be seen from the above technical solutions, the damped linear generator, design method, and damping control method provided by the embodiments of the present invention enable equipment that can supply power to superconducting electric maglev trains without adding additional damping devices to existing systems, and effectively enhance the electromagnetic stiffness of the bogie. This successfully overcomes the technical challenges of onboard power supply safety and inherent damping inadequacy in superconducting electric maglev trains. By accurately simulating the magnetic field distribution of the superconducting coil and optimizing the structure of the current collector coil, additional electromagnetic damping force is provided to the bogie, significantly improving the instability that may occur when the vehicle faces complex operating conditions, thereby enhancing the overall system's operational stability. Simultaneously, utilizing the principle of electromagnetic induction, an autonomous power supply function is achieved without relying on external power supply equipment, thus avoiding the technical limitations and bottlenecks brought about by traditional mechanical transmission devices and complex control systems. Furthermore, the method is universal and can be widely applied to various types of contactless harmonic linear generators as a core component of their damping adjustment systems, demonstrating strong application potential and value.

[0105] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed, and is not intended to limit the scope of the claimed invention, but merely to illustrate preferred embodiments of the invention. Those skilled in the art should understand that the scope of the invention is not limited to the specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A design method for a damped linear generator, characterized in that, The damped linear generator includes a superconducting coil, a figure-eight coil, and a damped current collector coil; wherein... The damping current collector coil is installed inside the superconducting coil shell on both sides of the bogie of the superconducting electric maglev train. It is used to collect the energy of the harmonic magnetic field of the air gap of the figure-eight coil. After rectification and filtering, it directly supplies power to the on-board electrical equipment and batteries of the superconducting electric maglev train. It generates electricity by utilizing the harmonic magnetic field in the superconducting electric maglev train's own system. The damping current collector coil is also used to receive the stable current converted from the vehicle battery by the vehicle power converter and injected into the damping current collector coil. At this time, the damping current collector coil simulates the magnetic field of the superconducting coil to generate an additional electromagnetic damping force. The design method includes the following steps: Step S1: Using the spatial harmonic method, the magnetic field of the superconducting coil is decomposed into Fourier components to obtain the y-axis component of the magnetic induction intensity of the superconducting coil. Step S2: Using the definitions of magnetic induction intensity, induced electromotive force, and circuit principles, the magnetic induction intensity B of the figure-eight coil is obtained. ey The expression for (x,y,z); Step S3: The maximum harmonic order of the air gap magnetic field is 2k-1, derived from the magnetic induction intensity formula of the figure-eight coil. Step S4: Install the damped collector coil on the outer shell of the superconducting coil, and keep the fundamental component of the air gap magnetic field and the damped collector coil stationary; place a set of collector coils within two maximum harmonic order periods, and satisfy the predetermined relationship between the pole pitch of the damped collector coil and the pole pitch of the u-phase coil in the damped linear collector coil to obtain the UVW three-phase sine wave. Step S5, based on the magnetic induction intensity B of the figure-eight coil ey The expression for (x,y,z) is used to obtain the induced electromotive force U of a single damped collector coil using the definition of induced electromotive force. c (x,y,z); Let the expected power output of the linear generator be P. According to the definition of current density, the current density of a single-turn coil is obtained. Step S6: Determine the wire type based on the single-turn coil current density, and specify the wire diameter and the number of turns of the UVW three-phase collector coil; Step S7: Keep the geometric center of the collector coil at the same horizontal position as the figure-eight coil.

2. The design method for a damped linear generator according to claim 1, characterized in that, The arrangement of the damped current collector coils is based on the arrangement of the UVW three-phase standard current collector coils. The electrode pitch between the VW phases remains constant, and two identical U-phase coils, u and u', are arranged on either side of the VW phases, ensuring that a set of uVWu' three-phase current collector coils can still generate a sine wave. At this time, adjacent sets of uVWu' current collector coils, due to the magnetic field of the superconducting range they cover being opposite in direction to the previous set, are connected in reverse to generate a magnetic field opposite to that of the previous set of damped coils. The electrode pitch between the u and -u, u' and -u', V and -V, and W and -W phase current collector coils remains equal to the actual superconducting electrode pitch τ. sx Damped current collector coils can simulate the magnetic field of superconducting coils by injecting stable current, thereby generating additional induced electromotive force in the figure-eight coil and increasing the electromagnetic damping of the system.

3. The design method for a damped linear generator according to claim 1, characterized in that, B, the y-axis component of the magnetic induction intensity of the superconducting coil sy (x,y,z) is: (1) In equation (1), the series n and m are both odd numbers, δ is the number of superconducting coils, and G s = λC s f s , λ = (k sx 2 +k sz 2 ) 1 / 2 C s =8μ0N s I s / τ x τ z f s = sin(k sx ·a s / 2)·sin(k sz ·b s / 2) / k sx k sz k sx = nπ / τ x k sz = mπ / τ z Vacuum permeability μ0 = 4π × 10 -7 Wb / (A·m), N s and I s These represent the number of turns of the superconducting coil and the injected current, τ, respectively. x and τ z Let a be the pole pitch of the superconducting coil along the x-axis and z-axis, respectively. s τ represents the equivalent length of the superconducting coil along the x-axis; sx b represents the true pole distance of the superconducting coil along the x-axis. s Let τ be the equivalent length of the superconducting coil along the z-axis, and its value satisfies: x >> τ sx ;τ z >> b s .

4. The design method for a damped linear generator according to claim 3, characterized in that, The magnetic flux density B of the figure-eight coil ey The expression for (x,y,z) is: (2) In equation (2), ε is the number of "8" coils, and P e = 4kμ0λN e f e / τ sx τ sz The maximum current I of the εth "8" coil at time t εmax =(-1) δ-1 Z e F e The impedance Z of the figure-eight coil e = jnωN e / (jnωL e +R e ), F e = G e ·[cos(k sz z eB )-cos(k sz z eU )]e -λye G e = 4f e G s f e = sin(k sx ·a e / 2)·sin(k sz ·b e / 2) / k sx k sz ; k is the ratio of the superconducting coil pole pitch to the "8" coil pole pitch, and k ≠ 1, N e L is the number of turns of the figure-eight coil. e and R e These are the self-inductance and resistance of the figure-eight coil, respectively. e and b e These are the equivalent lengths of the figure-eight coil on the x-axis and z-axis, respectively. eU and z eB These are the z-coordinates of the upper and lower individual figure-eight coils, respectively, on the x-axis and y-axis. e The coordinates of the figure-eight coil on the y-axis.

5. The design method for a damped linear generator according to claim 4, characterized in that, In step S4, the pole spacing τ of the damped collector coil cx The following relationship must be satisfied to obtain the UVW three-phase sine wave: (3) The pole pitch τ of the u-phase coil in a damped linear collector coil cu Satisfy the following formula: (4) In equation (4), a cv and a cu These are the equivalent lengths of the VW phase and uu´ phase coils, respectively, e cv and e cu Let e ​​be the cross-sectional length of the VW phase and uu´ phase coils, respectively, and let e be the cross-sectional length of the coils. cv =N cv D c / K c e cu =N cu D c / K c N cv and N cu The numbers of turns for the VW and uu´ phase coils are respectively, D c K represents the wire diameter. c is the fill factor of the collector coil.

6. The design method for a damped linear generator according to claim 5, characterized in that, In step S5, the induced electromotive force U of a single damped collector coil c (x,y,z) is: (5) In Equation (5), G c | 2k-1 = 128k 2 μ0N c N e ωI εmax | 2k-1 f e | 2k-1 (f cU | 2k-1 -f cB | 2k-1 )λ| 2k-1 / τ sx τ sz ; k sx | 2k-1 = (2k - 1)π / τ sx ,λ| 2k-1 = (k sx | 2k-1 2 +k sz 2 ) 1 / 2 ,I εmax | 2k-1 =(-1) δ Z e G e | 2k-1 ,f e | 2k-1 = sin(k sx | 2k-1 ·a e / 2)sin(k sz ·b e / 2) / k sx | 2k-1 k sz ,f cU | 2k-1 = sin(k sx | 2k-1 ·a c / 2)sin(k sz ·b cU / 2) / k sx | 2k-1 k sz ,f cB | 2k-1 = sink sx | 2k-1 ·a c / 2)sin(k sz ·b cB / 2) / k sx | 2k-1 k sz ; z cU and z cB Let b be the coordinates of the center points of the upper and lower collector coils on the z-axis. cU and b cB These are the lengths of the upper and lower collector coils along the z-axis, respectively.

7. The design method for a damped linear generator according to claim 6, characterized in that, The current density J of a single-turn coil is: (6) In equation (6), S is the cross-sectional area of ​​a single collector coil, and cosφ is the power factor of the power supply line.

8. A damping control method for a magnetic levitation train, characterized in that, The method is implemented by a damped linear generator designed according to any one of the design methods in claims 2-7; First, the damped current collector coil is installed inside the casing of the superconducting coil according to the designed connection method, position design and arrangement structure of the current collector coil, to obtain a damped linear generator; Next, perform the following steps: Step S21: The damped linear generator uses the harmonic magnetic field of the figure-eight coil to convert AC power into DC power through the rectification stage to power the vehicle-mounted electrical equipment and the battery. Step S22: Real-time determination of the battery charge status; when the battery status is determined to be in a discharging state, stop supplying power to the battery and proceed to step S23. In step S23, the battery supplies a stable DC current to the damped current collector coil via a converter, thereby generating additional electromagnetic force and enhancing the electromagnetic stiffness of the bogie.

9. The damping control method for a magnetic levitation train according to claim 8, characterized in that, In step S22, the charging and discharging conditions of the battery first determine its state of charge (SOC): (7) In equation (7), Q r Q represents the remaining battery capacity. rated The battery is rated to light up; the battery's state of charge and its terminal voltage V bat Closely related to the battery's terminal voltage, when the battery's charge level is within the range of 20% to 80%, the change in the battery's terminal voltage is relatively gradual. Judging the battery's charge level helps determine the battery's charging and discharging conditions. During battery charging and discharging, firstly, AC power is converted into DC power through rectification and filtering, which can then directly power the vehicle's electrical equipment. Secondly, the battery's state of charge is estimated by collecting the battery's terminal voltage and current. The terminal voltage V is set according to different battery types. When the battery's state of charge is below 20%, switch S is closed. c Disconnect switch S d The battery enters the charging state; When the battery charge is above 80%, disconnect switch S. c Close switch S d The battery enters a discharging state.

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