An eddy current braking system and maglev train

Abstract

The application provides a kind of eddy current braking system and magnetic suspension train, it is related to magnetic suspension train technical field.The system includes eddy current braking controller and multiple electromagnet units distributed along guide rail direction, each unit contains first and second electromagnet and corresponding control switch distributed in sequence, and the units are connected in series;Eddy current braking controller dynamically adjusts the number of electromagnet units put into according to required braking force and real-time collected parameters such as vehicle speed and air gap, through control switch state, realizes the continuous adjustable of braking force.The application can effectively solve the problem of nonlinearity, step and large disturbance of speed and air gap of traditional eddy current braking system, which leads to discontinuous braking, and improves the stability and comfort of train braking.

Description

Technical Field

[0001] This invention relates to the field of magnetic levitation train technology, specifically to an eddy current braking system and a magnetic levitation train. Background Technology

[0002] Maglev trains are a new type of train without wheels and gear transmission mechanisms. Due to the train's levitated state, the mechanical contact friction between the train and the track disappears, allowing the train to reach very high speeds. Its braking method is difficult to employ using conventional physical braking; instead, non-contact eddy current braking is typically used. The basic principle of eddy current braking is as follows: when the brake moves relative to the track, it generates a magnetic field. According to the principle of electromagnetic induction, the changing magnetic flux induces a voltage current. The magnetic field generated by this current is opposite to the excitation magnetic field. The combined effect is that the magnetic field at the front end of the core in the direction of travel is weakened, while the magnetic field at the rear is strengthened, thus reducing the vertical force and forming a horizontal component force in the opposite direction of travel—this force is the braking force.

[0003] In terms of control strategy, existing systems typically employ a graded current regulation method, where the brake controller has several preset fixed current levels, each corresponding to a braking force level. When the onboard braking unit issues a braking command, the controller can only output the corresponding stepped current according to the preset level. At this time, the electromagnetic braking system will generate a step-like braking force, causing the train to experience a noticeable jerk during braking. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide an eddy current braking system and a magnetic levitation train to provide a braking scheme capable of smooth braking.

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

[0006] An eddy current braking system includes: an eddy current braking controller and N electromagnet units, wherein N is a positive integer not less than 2;

[0007] The N electromagnet units are distributed sequentially between the train's suspension frame along the guide rail direction;

[0008] The N electromagnet units are connected in series, wherein the negative terminal of the excitation power supply of the upstream electromagnet unit is connected to the positive terminal of the excitation power supply of the downstream electromagnet unit. Each electromagnet unit includes: a first electromagnet, a second electromagnet, a first control switch, and a second control switch; the first end of the first electromagnet is connected to the positive terminal of the excitation power supply of the electromagnet unit through the second control switch, and the second end of the second electromagnet is connected to the second end of the first electromagnet; the first end of the second electromagnet is connected to the positive terminal of the excitation power supply of the electromagnet unit through the first control switch, and the first end of the second electromagnet is also connected to the negative terminal of the excitation power supply; the first electromagnet and the second electromagnet are arranged in the same direction in the first direction, and when the first electromagnet and the second electromagnet are energized, the magnetism at both ends of the electromagnet unit is the same;

[0009] The eddy current brake controller is used to control the number of electromagnet units engaged after receiving the required braking force sent by the vehicle brake control unit, by controlling the first control switch and the second control switch in each of the electromagnet units, so that the engaged electromagnet units generate the required braking force.

[0010] Optionally, in the above-mentioned eddy current braking system, N is an even number, wherein N / 2 adjacent electromagnet units are distributed between the first suspension frame and the second suspension frame, and the remaining electromagnet units are distributed between the second suspension frame and the third suspension frame, wherein the first suspension frame, the second suspension frame, and the third suspension frame are three adjacent suspension frames.

[0011] Optionally, in the above-mentioned eddy current braking system, the electromagnet unit further includes:

[0012] Unit control board, switch driver board, and data acquisition board;

[0013] The unit control board is used to acquire the switch control command sent by the eddy current brake controller, forward the switch control command to the switch drive board, acquire the acquisition result of the data acquisition board, and send the acquisition result to the eddy current brake controller.

[0014] The switch driver board is used to drive the conduction state of the first control switch and the second control switch based on the acquired switch control command;

[0015] The data acquisition board is used to detect the working status data of the electromagnet unit.

[0016] Optionally, in the above-mentioned eddy current braking system, the data acquisition board includes:

[0017] At least one of voltage acquisition board, gap acquisition board, and temperature acquisition board;

[0018] The voltage acquisition board is used to acquire the voltage across the first electromagnet and the second electromagnet.

[0019] The gap acquisition plate is used to acquire the gap between the first electromagnet, the second electromagnet and the side rail;

[0020] The temperature acquisition board is used to acquire the temperature of the first electromagnet and the second electromagnet.

[0021] Optionally, in the above-mentioned eddy current braking system, the number of electromagnet units engaged is controlled by controlling the first and second control switches in each of the electromagnet units, so that the engaged electromagnet units generate the required braking force, including:

[0022] Obtain the required braking force sent by the vehicle's braking control unit;

[0023] The actual value of the total braking force provided by all electromagnet units in the eddy current braking system is obtained. The actual value of the braking force of a single electromagnet unit is calculated based on the train speed, the air gap between the electromagnet and the guide rail, and the excitation current of the electromagnet.

[0024] Calculate the difference in braking force between the required braking force and the actual braking force value;

[0025] The number of electromagnet units to be engaged or disengaged is calculated based on the braking force difference and the maximum braking force that a single electromagnet unit can provide.

[0026] Based on the number of electromagnet units to be put in or cut out, select and control the corresponding electromagnet units to be put in or cut out.

[0027] Optionally, in the above-described eddy current braking system, the eddy current braking controller is further used for:

[0028] The target value of the supporting capacitor voltage is calculated based on the total number of electromagnet units currently in operation, as well as the excitation voltage reference allocated to the electromagnets. The higher the total number of electromagnet units currently in operation, the higher the target value of the supporting capacitor voltage.

[0029] The supporting capacitor voltage is adjusted in a closed loop based on the target value and the measured value of the supporting capacitor voltage, and the excitation voltage of the electromagnet is adjusted in a closed loop based on the excitation voltage reference and the measured value of the excitation voltage.

[0030] Optionally, in the above-mentioned eddy current braking system, the eddy current braking controller is further used to acquire the temperature signal, current signal, and fault status information of the electromagnet unit in the activated state, and to determine whether it is necessary to maintain the electromagnet unit in the activated state based on the temperature signal, current signal, and fault status information.

[0031] Optionally, in the above-mentioned eddy current braking system, the eddy current braking controller is further configured to: generate a pool of available electromagnet units based on the temperature signal, current signal, and fault status information; and send a warning message indicating insufficient braking capacity to the vehicle braking control unit when the number of electromagnet units in the pool of available electromagnet units is less than the total number of electromagnet units required to be deployed.

[0032] A magnetic levitation train, comprising the eddy current braking system described in any one of the above claims.

[0033] Optionally, the above-mentioned maglev train is equipped with an eddy current braking system on each side, and the two eddy current braking systems are symmetrically distributed.

[0034] Therefore, this application provides an eddy current braking system and a magnetic levitation train. This solution employs N electromagnet units connected in series, with each unit capable of independent switching. Thus, by controlling the number of operational units, the total braking force exhibits a linear variation with the number of units, effectively solving the problems of discontinuous braking force adjustment and response lag caused by the nonlinear relationship between current and force in traditional eddy current braking. Since each electromagnet unit includes a first electromagnet and a second electromagnet with identical magnetic properties and distributed in the same direction, this structure enhances the local magnetic field strength and improves the unit current braking force under low-speed conditions, overcoming the deficiency of insufficient braking force in the low-speed range of existing technologies. Because the eddy current braking controller can precisely control the number of operational units according to real-time operating conditions, it avoids the severe impact and energy waste caused by high-current full-power operation, thus significantly improving the smoothness of the braking process, passenger comfort, and the system's energy efficiency. The series connection of each unit ensures the consistency of current across all operational units, simplifies the control logic, and improves the system's robustness in complex electromagnetic environments. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0036] Figure 1 An overall framework diagram of the eddy current braking system provided in the embodiments of this application;

[0037] Figure 2 This is a schematic diagram of the structure of the electromagnet unit provided in the embodiments of this application;

[0038] Figure 3A schematic diagram of the magnetic distribution of the electromagnet in the electromagnet unit provided in this application embodiment after being energized;

[0039] Figure 4 A schematic diagram of the protection logic of the unit control board provided in the embodiments of this application;

[0040] Figure 5 A flowchart illustrating a method for calculating and controlling the number of electromagnet units based on braking force difference, provided in an embodiment of this application.

[0041] Figure 6 This is a schematic diagram of the structure of the eddy current braking controller provided in the embodiments of this application;

[0042] Figure 7 A schematic diagram of the control principle of each control switch in the eddy current braking controller provided in the embodiments of this application; Detailed Implementation

[0043] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] like Figure 1As shown, this embodiment provides an eddy current braking system, which includes an eddy current braking controller 10 and N electromagnet units 20. The N electromagnet units 20 are sequentially distributed between the train's suspension frames along the guide rail direction. Specifically, the N electromagnet units 20 constitute the execution terminal of the eddy current braking system, arranged along the train's travel direction (i.e., the guide rail direction) and installed in the space between adjacent suspension frames. This layout fully utilizes the mechanical structural space between the suspension frames, allowing the electromagnet units 20 to be arranged as close as possible to the guide rail surface, thereby maximizing magnetic coupling efficiency. N is a positive integer not less than 2, meaning the system contains at least two electromagnet units 20. Through modular quantity configuration, the total number of electromagnet units 20 can be flexibly adjusted according to the train's axle load, braking power requirements, and installation space; for example, it can be 12 or even more. This embodiment does not impose any special limitation on this. The N electromagnet units 20 are connected in series, wherein the negative excitation power interface of the upstream electromagnet unit 20 is connected to the positive excitation power interface of the downstream electromagnet unit 20. In this embodiment, the electromagnet units 20 are electrically connected in series, meaning the negative terminal of the excitation power supply of the preceding unit is electrically connected to the positive terminal of the excitation power supply of the following unit. It should be understood that, to achieve this series connection, the electromagnet units 20 are physically connected via high-voltage cables or busbars, and the connection path should be as short as possible to reduce stray inductance and resistance loss.

[0045] See Figure 2 Each electromagnet unit 20 includes a first electromagnet T1, a second electromagnet T2, a first control switch S1, and a second control switch S2. Specifically, a single electromagnet unit 20, as an independently controllable minimum magnetic pole module, integrates two electromagnet coils and two control switches. The first electromagnet T1 and the second electromagnet T2 are the core components for generating the excitation magnetic field, typically consisting of an iron core and a coil wound around the iron core. The first control switch S1 and the second control switch S2 are the key actuators for controlling whether the electromagnet unit 20 is connected to the excitation circuit. Their specific implementation can be a mechanical switch such as a contactor, which is not limited in this application.

[0046] The first end of the first electromagnet T1 is connected to the positive terminal of the excitation power supply of the electromagnet unit 20 via the second control switch S2, and the second end of the second electromagnet T2 is connected to the second end of the first electromagnet T1. In this circuit structure, the first electromagnet T1 and the second control switch S2 are connected in series to the positive terminal of the power supply, while the second electromagnet T2 is connected to the first electromagnet T1 at its end, forming a specific circuit topology. Specifically, the first and second ends of the first electromagnet T1 refer to the two terminals of its coil winding, respectively. The second control switch S2, as the first gate of the switching control, is connected in series in the power supply circuit of the first electromagnet T1 to control the on / off state of this branch.

[0047] The first end of the second electromagnet T2 is connected to the positive terminal of the excitation power supply of the electromagnet unit 20 via the first control switch S1, and the first end of the second electromagnet T2 is also connected to the negative terminal of the excitation power supply. In this embodiment, the connection point of the first end of the second electromagnet T2 constitutes a key node inside the unit, which is connected to one end of the first control switch S1 and the negative terminal of the excitation power supply, respectively. When the first control switch S1 and the second control switch S2 are in different state combinations, the path and direction of the current flowing through the first electromagnet T1 and the second electromagnet T2 can be controlled, thereby achieving precise regulation of the working state of the electromagnet unit 20. For example, in one embodiment, by controlling the first control switch S1 to be closed and the second control switch S2 to be open, the current flows through the positive terminal of the power supply, through the first control switch S1 into the second electromagnet T2, and then flows back to the negative terminal of the power supply through the first electromagnet T1, so that the electromagnet unit 20 is in the working state. In one embodiment, by controlling the first control switch S1 to open and the second control switch S2 to close, the second electromagnet T2 and the first electromagnet T1 are short-circuited, and the current directly passes through the electromagnet unit 20 and enters the downstream electromagnet unit 20. In another embodiment, by controlling the first control switch S1 to open and the second control switch S2 to open, the series branch is broken, and each electromagnet unit 20 does not work.

[0048] The first electromagnet T1 and the second electromagnet T2 are distributed in the same direction in the first direction, and when the first electromagnet T1 and the second electromagnet T2 are energized, the magnetism at both ends of the electromagnet unit 20 is the same, and the magnetism at both ends of each electromagnet is as follows: Figure 3 As shown. Specifically, the first direction refers to the direction of rail extension or train travel. The first electromagnet T1 and the second electromagnet T2 are arranged sequentially in physical space along this direction, and their winding directions or current inflow directions are configured such that the magnetic poles they generate after being energized have the same polarity. For example, Figure 2 As shown, if the lower end of the first electromagnet T1 is the N pole, then the lower end of the second electromagnet T2 is also the N pole, thus forming a polarity along the guide rail direction as shown in the diagram. Figure 3The magnetic field distribution is shown. Its magnetic field distribution characteristics can be described by the Biot-Savart law for a current flowing through it. The magnetic induction intensity produced by the coil at a certain point in space. With current It is directly proportional to the square of the distance and inversely proportional to the square of the distance. The typical relationship can be expressed as follows: ,in, Magnetic flux density The permeability of free space, For excitation current, It is a current element vector. Let be the position vector of the current element pointing to the field point. This formula shows that by controlling the excitation current... The size and direction of the magnetic field directly determine the magnetic flux density. The strength and polarity of the force affect the magnitude of the braking force.

[0049] The eddy current brake controller 10 is communicatively connected to the on-board brake control unit 00 to acquire the required braking force sent by the on-board brake control unit 00. After acquiring the required braking force, it controls the number of electromagnet units 20 engaged by controlling the first control switch S1 and the second control switch S2 in each electromagnet unit 20, so that the engaged electromagnet units 20 generate the required braking force. As the decision-making core of the entire braking system, the eddy current brake controller 10 is connected to the on-board brake control unit 00 through the on-board network and receives the required braking command containing the magnitude of the required braking force. After receiving the command, the eddy current brake controller 10 calculates the target number of electromagnet units 20 that need to be engaged, based on feedback parameters such as the current train speed and air gap. Subsequently, the controller sends drive signals to a corresponding number of electromagnet units 20, controlling the opening of the first control switch S1 and the closing of the second control switch S2 within each unit. This controls the closing of the first control switch S1 and the opening of the second control switch S2 in other electromagnet units 20, keeping the electromagnets in the unselected units 20 in a short-circuit state, while allowing current to flow through the electromagnets in the selected units 20. Through this discrete unit switching control, the system achieves graded adjustment of the total braking force. The number of electromagnet units put in is 20. The relationship between them can be approximated as: ,in, The actual number of electromagnet units deployed is 20. For a single electromagnet unit 20 at the current vehicle speed and air gap The reference braking force generated by the action.

[0050] The working process and principle of the above scheme are as follows: When the train needs to brake, the eddy current brake controller 10 first receives the required braking force signal from the on-board brake control unit 00, and collects the train's running speed and the air gap state between the electromagnet and the guide rail in real time. The controller calculates the optimal number and specific number of the electromagnet units 20 required to generate the required braking force based on a preset control algorithm or mapping table. Subsequently, the controller outputs control commands to the selected electromagnet units 20, causing their first control switch S1 to open and their second control switch S2 to open, thereby connecting the excitation power supply to the first electromagnet T1 and the second electromagnet T2 of that unit. At this time, the excitation current flows through the electromagnet coil, generating a strong magnetic field in the iron core. This magnetic field passes through the air gap and acts on the surface of the guide rail. Due to the relative motion between the train and the guide rail, the changing magnetic field induces eddy currents inside the guide rail. According to Lenz's law, the magnetic field generated by these eddy currents interacts with the original magnetic field, generating a braking force opposite to the direction of train movement. In the unselected electromagnet units 20, the first control switch S1 is closed and the second control switch S2 is open. By dynamically adjusting the number of units in operation, the total braking force output by the system changes accordingly, thereby achieving real-time tracking of the required braking force.

[0051] The above-described scheme employs N electromagnet units 20 connected in series, with each unit capable of independent switching. Therefore, by controlling the number of operational units, the total braking force exhibits a linear variation with the number of units, effectively solving the problems of discontinuous braking force adjustment and response lag caused by the nonlinear relationship between current and force in traditional eddy current braking. Since each electromagnet unit 20 includes a first electromagnet T1 and a second electromagnet T2 with identical magnetic properties and distributed in the same direction, this structure enhances the local magnetic field strength and improves the unit current braking force under low-speed conditions, thus overcoming the deficiency of insufficient braking force in the low-speed range of existing technologies. Because the eddy current brake controller 10 can precisely control the number of operational units according to real-time operating conditions, it avoids the severe impact and energy waste caused by high-current full-power operation, thus significantly improving the smoothness of the braking process, passenger comfort, and the system's energy efficiency. The series connection of each unit ensures the consistency of current across all operational units, simplifies the control logic, and improves the system's robustness in complex electromagnetic environments.

[0052] In another alternative embodiment, this application provides a distribution pattern of the electromagnet units 20. For example... Figure 1 As shown, N is an even number, and N / 2 adjacent electromagnet units 20 are distributed between the first suspension frame (1# suspension frame) and the second suspension frame (2# suspension frame). The remaining electromagnet units 20 are distributed between the second suspension frame and the third suspension frame (3# suspension frame). The first suspension frame, the second suspension frame and the third suspension frame are three adjacent suspension frames.

[0053] Specifically, this distribution method evenly distributes an even number of electromagnet units 20 into two adjacent suspension frame sections. The first half of the electromagnet units 20 are arranged in the space between the first and second suspension frames, while the latter half are arranged in the space between the second and third suspension frames. The first, second, and third suspension frames are arranged sequentially along the train's direction of travel, collectively forming the physical structure supporting the car body. This symmetrical spatial layout design fully utilizes the available longitudinal installation space between adjacent suspension frames, resulting in a more balanced distribution of the eddy current braking system under the car body. By distributing the electromagnet units 20 across two independent sections, problems such as excessively strong local magnetic fields, concentrated heat generation, and excessive local structural stress caused by concentrating all electromagnet units 20 between a single suspension frame are effectively avoided. This helps optimize the longitudinal weight distribution and center of gravity of the car body. Furthermore, this distribution method, combined with the unified scheduling of the eddy current brake controller 10, enables coordinated control or independent switching of the two sections of electromagnet units 20, thereby providing a more uniform distribution of braking force during train braking, reducing pitch vibration and head-nodding motion of the car body during braking, and improving the smoothness of the train braking process and ride comfort.

[0054] Through the above technical solution, this application achieves an optimized layout of the electromagnet units 20 in a multi-suspension frame structure. Since N is an even number and evenly distributed across two adjacent sections, the hardware resources of the two braking sections are symmetrical, allowing the eddy current brake controller 10 to flexibly allocate the number of electromagnet units 20 operating in the two sections according to actual braking requirements. This layout not only solves the physical constraint problem of arranging a large number of electromagnet units 20 within the limited space at the bottom of the vehicle body, but also provides a certain degree of redundancy and fault tolerance for the system through physical partitioning and isolation. For example, when some electromagnet units 20 in one section fail, the electromagnet units 20 in another section can still provide basic braking force, thereby significantly improving the overall safety and reliability of the high-speed maglev train's eddy current braking system.

[0055] Further reference Figure 2 The illustration shows a specific structure of the electromagnet unit 20 described above in this application. The electromagnet unit 20 includes: a unit control board 21, a switch drive board 22, and a data acquisition board.

[0056] The unit control board 21 is used to acquire the switching control commands sent by the eddy current brake controller 10 and forward them to the switch drive board 22. It also acquires the data acquisition results from the data acquisition board and sends these results to the eddy current brake controller 10. Alternatively, it can further analyze the acquisition results to determine the available status (available / unavailable) of the electromagnet unit 20, the electromagnet status (engaged / disengaged), the electromagnet voltage and current, the gap, the communication status of each board, the communication status of the unit control board 21, the switch status (open / closed), the power supply status, overvoltage, overcurrent, abnormal engagement, overheating, and other data, and then send this data to the eddy current brake controller 10. Simultaneously, the unit control board 21 can also protect the electromagnet unit 20 based on this data; for details, see [link to relevant documentation]. Figure 4 After receiving the switch control command for controlling the operation of the electromagnet unit 20, it controls the first control switch S1 and the second control switch S2 to perform a cut-in operation (the second control switch S2 is closed and the first control switch S1 is open). Then, it acquires the voltage across the first electromagnet T1 and the second electromagnet T2 and determines whether there is voltage applied to the first electromagnet T1 and the second electromagnet T2. If there is no voltage applied, it controls the first control switch S1 and the second control switch S2 to perform a cut-out operation (the second control switch S2 is open and the first control switch S1 is closed). When there is voltage applied, it performs overcurrent detection and temperature detection on the first electromagnet T1 and the second electromagnet T2 in real time. When overcurrent or overheating is detected, it controls the first control switch S1 and the second control switch S2 to perform a cut-out operation. At the same time, it detects the power module in the electromagnet unit 20 to determine whether the power module is normal. When the power module is abnormal, it also needs to control the first control switch S1 and the second control switch S2 to perform a cut-out operation. When controlling the first control switch S1 and the second control switch S2 to perform a cut-in or cut-out operation, it needs to simultaneously inform the eddy current brake controller 10 of this operation.

[0057] The switch driver board 22 is used to drive the conduction state of the first control switch S1 and the second control switch S2 based on the acquired switch control command, so as to perform a cut-in or cut-out operation.

[0058] The data acquisition board is used to detect the working status data of the electromagnet unit 20.

[0059] Each module in the eddy current braking system described in the above embodiments can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0060] Furthermore, the electromagnet unit 20 may also include a power board 1124, which is connected to the vehicle power supply and is used to convert the output voltage of the vehicle power supply into the rated voltage of each power module in the electromagnet unit 20 and to supply power to each power module.

[0061] Further, see Figure 2 The data acquisition board includes at least one of the following: voltage acquisition board 231, gap acquisition board 232, and temperature acquisition board 233.

[0062] Among them, voltage acquisition board 231 is used to acquire the voltage or current at both ends of the first electromagnet T1 and the second electromagnet T2 respectively; gap acquisition board 232 is used to acquire the gap between the first electromagnet T1, the second electromagnet T2 and the side rail; temperature acquisition board 233 is used to acquire the temperature of the first electromagnet T1 and the second electromagnet T2.

[0063] By setting up the voltage acquisition board 231, the terminal voltage of the coil in the electromagnet unit 20 can be monitored in real time, thereby reflecting the on / off state of the excitation circuit and the change in coil impedance. By setting up the gap acquisition board 232, the size of the air gap between the electromagnet and the side rail can be accurately obtained. This data can be used to correct the braking force calculation model to compensate for the braking force fluctuation caused by air gap disturbance. By setting up the temperature acquisition board 233, the temperature of the electromagnet body can be monitored in real time to prevent equipment damage due to overheating and to provide data support for the prediction of the electromagnet's lifespan. The combined use of one or more of the above acquisition boards can provide multi-dimensional status feedback for the eddy current brake controller 10, significantly improving the accuracy of the braking force closed-loop control and the safety of the system.

[0064] One possible implementation is, such as Figure 5 The diagram shows a flowchart of a method for calculating and controlling the number of electromagnet units deployed based on the braking force difference, according to an embodiment of this application. This method controls the number of deployed electromagnet units 20 by controlling the first control switch S1 and the second control switch S2 in each electromagnet unit 20, thereby enabling the deployed electromagnet units 20 to generate the required braking force. The method further includes:

[0065] Step S501: Obtain the required braking force sent by the vehicle braking control unit 00.

[0066] The eddy current brake controller 10 is connected to the train's onboard brake control unit (BCU) via a communication interface board 15, receiving braking commands from the BCU in real time. This braking command represents the required braking force, the value of which is calculated by the BCU based on the train's current operating status, track conditions, driver instructions, or the train operation control curve of the automatic driving system. The required braking force characterizes the target deceleration force level required for the train to maintain a predetermined speed curve or to stop safely within a specified distance. The eddy current brake controller 10 uses this required braking force as a given input to the outer loop control system, serving as a reference for subsequently adjusting the number of electromagnet units 20 engaged and the magnitude of the excitation current.

[0067] Step S502: Obtain the actual value of the total braking force provided by all electromagnet units 20 in the eddy current braking system. The actual value of the braking force of a single electromagnet unit 20 is calculated based on the train speed, the air gap between the electromagnet and the guide rail, and the excitation current of the electromagnet.

[0068] Since eddy current braking force is a non-contact force and cannot be directly measured by physical sensors, this embodiment uses real-time calculation to obtain the actual value of the total braking force. The eddy current brake controller 10 obtains the real-time operating parameters of each engaged electromagnet unit 20 from the data acquisition board, specifically including the train speed. The air gap formed between the electromagnet pole face and the side rail and the excitation current flowing through the electromagnet coil .

[0069] For a single electromagnet unit 20, a calculation model for the actual value of the braking force is established based on the principle of electromagnetic induction and the physical characteristics of eddy current braking. This process can be formally expressed as the following functional relationship:

[0070]

[0071] In the formula, Indicates the first The actual value of the braking force generated by each electromagnet unit 20; This represents the relative permeability of an electromagnet; Indicates the permeability of free space; Indicates the distance between adjacent magnetic poles of the same polarity; Indicates the orbital conductivity; Indicates the diameter of the vortex region; Indicates the number of turns of a coil for a pair of magnetic poles; This represents the excitation current in the coil; This indicates the speed of the braking magnetic pole relative to the side rail; Indicates the length of the magnetic circuit in the iron core; This indicates the gap between the electromagnet and the side rail; This represents the conversion parameter, which is usually set to 1.5.

[0072] Based on the above formula, the braking force of all electromagnet units 20 currently in the eddy current braking system is calculated, and the actual braking force values ​​of each in-operation electromagnet unit 20 are summed to obtain the total actual braking force currently provided by the eddy current braking system. The actual value of the total braking force serves as a feedback signal, reflecting the current physical output level of the braking system in real time. , … This represents the distance between the same polarity magnetic poles of adjacent electromagnet units 20. As can be seen from the above formula, the magnitude of the eddy current braking force is affected by many factors, including the excitation current in the coil. It is proportional to the square of the velocity. and the gap between the electromagnet and the side rail The relationship is non-linear and proportional to the magnetic poles applied. If the distance between magnetic poles of the same polarity remains constant, the relationship is linear.

[0073] Step S503: Calculate the difference between the required braking force and the actual braking force.

[0074] The control principle of eddy current braking is to calculate the appropriate required braking force based on information such as the train's current speed, position, and the state of the electromagnets, so that the train can reliably stop at the designated stopping area with a safe and comfortable deceleration. After obtaining the required braking force... and actual value of total braking force Then, subtract these two quantities to calculate the difference in braking force. The calculation logic is as follows: This braking force difference quantifies the deviation between the actual braking force obtained by the train and the target braking force. If the braking force difference is positive, it indicates that the current braking force is insufficient, and the number of electromagnet units 20 needs to be increased or the excitation current needs to be increased; if the braking force difference is negative, it indicates that the current braking force exceeds the demand, and there is a risk of over-braking, so the number of electromagnet units 20 needs to be reduced; if the braking force difference is within the preset allowable error range, the current state of electromagnet units 20 is maintained. This step realizes the key link of precise closed-loop control of braking force, and provides direct quantitative basis for subsequent dynamic adjustment.

[0075] Step S504: Calculate the number of electromagnet units 20 that need to be engaged or disengaged based on the braking force difference and the maximum braking force that a single electromagnet unit 20 can provide.

[0076] To eliminate the braking force difference, the braking force difference is combined with... and the maximum braking force that a single electromagnet unit 20 can provide under the current operating conditions. Calculate the number of electromagnet units 20 that need adjustment. Calculate the maximum braking force of a single electromagnet unit 20. Also affected by train speed and air gap The effect of this can be calculated based on the calculation model in step S402 when the excitation current reaches its rated maximum value.

[0077] The required number of electromagnet units 20 to be inserted or cut out The calculation process, for example, uses an up-rounding function to ensure sufficient braking force reserve and avoid braking force shortages due to insufficient quantity. This logic can be expressed as:

[0078]

[0079] In the formula, This represents the floor function. When the calculation result... When the result is positive, it indicates that the corresponding number of electromagnet units 20 need to be engaged; when the result is negative, its absolute value indicates the number of electromagnet units 20 that need to be cut off. Through this calculation step, the system can determine the minimum number of physical unit adjustments required to achieve the target braking force, thereby minimizing the number of switching actions and extending the equipment life while ensuring braking requirements.

[0080] Step S505: Based on the number of electromagnet units 20 to be put in or cut out, select and control the corresponding electromagnet units 20 to be put in or cut out.

[0081] After determining the number of electromagnet units 20 that need adjustment, a specific switching control strategy is executed. First, the current health status of all electromagnet units 20 is queried, and those in a usable state (no overheating, no overcurrent, and normal communication) are selected as a candidate pool. If an electromagnet unit 20 needs to be activated, the corresponding number of electromagnet units 20 are selected from the candidate pool according to a preset strategy (e.g., polling balancing strategy, priority activation of low-temperature zones strategy, or nearest-neighbor switching strategy), and activation commands are sent to the unit control boards 21 of these electromagnet units 20. Upon receiving the command, the unit control board 21 controls the first control switch S1 to open and the second control switch S2 to close, connecting the electromagnet unit 20 to the excitation main circuit. If an electromagnet unit 20 needs to be deactivated, the corresponding number of units are selected from the currently activated electromagnet units 20, a deactivation command is sent, and the first control switch S1 is closed and the second control switch S2 is opened, removing the electromagnet unit 20 from the excitation main circuit. Through the above selection and control actions, the eddy current braking system dynamically adjusts the number of electromagnet units 20 involved in the operation, so that the total braking force output can quickly follow and stabilize near the required braking force, realizing the continuous adjustment and smooth output of braking force.

[0082] Through the above steps, the eddy current braking system establishes a complete closed-loop link from demand braking force acquisition, actual braking force feedback calculation, difference analysis, quantity decision-making to final execution control. This link utilizes the discrete switching characteristics of the electromagnet unit 20, combined with real-time braking force estimation based on a physical model, to achieve fine-tuning of the nonlinear eddy current braking force. This control method not only solves the problem of stepped changes in braking force caused by traditional fixed-gear current control, but also maintains the stability and accuracy of braking force output under dynamic conditions such as train speed fluctuations and changes in suspension gap by adaptively increasing or decreasing the number of electromagnet units 20, thereby significantly improving the smoothness and comfort of the high-speed maglev train braking process.

[0083] Eddy current brake controller 10 is also used to provide excitation current to the electromagnet unit, see [link to relevant documentation]. Figure 6 In this embodiment, the eddy current braking controller 10 may specifically include: a power supply board 11, a control board 12, a drive board 13, a data acquisition board 14, a communication interface board 15, an interleaved parallel boost converter circuit 16, an electromagnet excitation modulation circuit 17, a first capacitor C1, and a second capacitor C2.

[0084] The interleaved parallel boost converter circuit 16 includes a first inductor L1, a second inductor L2, a third inductor L3, a fourth inductor L4, a first switch Q1, a second switch Q2, a third switch Q3, a fourth switch Q4, a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The first ends of the first inductors L1 to L4 are connected to the vehicle DC power supply. The first ends of the first diode D1 and the first switch Q1 are connected to the second end of the first inductor L1. The first ends of the second diode D2 and the second switch Q2 are connected to the second end of the second inductor L2. The first ends of the third diode D3 and the third switch Q3 are connected to the second end of the third inductor L3. The first ends of the fourth diode D4 and the fourth switch Q4 are connected to the second end of the fourth inductor L4. The control terminals of the first switches Q1 to Q4 are connected to the driver board 13.

[0085] The electromagnet excitation modulation circuit 17 includes a fifth switch Q5, a sixth switch Q6, a seventh switch Q7, and an eighth switch Q8. The first terminals of the fifth switch Q5 and the eighth switch Q8 are connected to the second terminals of the first diode D1 to the fourth diode D4. The first terminal of the seventh switch Q7 is connected to the second terminal of the fifth switch Q5. The first terminal of the sixth switch Q6 is connected to the second terminal of the eighth switch Q8. The control terminals of the fifth switch Q5, the sixth switch Q6, the seventh switch Q7, and the eighth switch Q8 are connected to the drive board 13. The fifth switch Q5 and the seventh switch Q7 serve as the positive output interface of the excitation current, and the eighth switch Q8 and the sixth switch Q6 serve as the negative output interface of the excitation current.

[0086] The first terminal of the first capacitor C1 is connected to the vehicle DC power supply, and the second terminal of the first capacitor C1 is grounded. The first terminal of the second capacitor C2 is connected to the second terminal of the first diode D1 to the fourth diode D4, and the second terminal of the second capacitor C2 is grounded.

[0087] The power input terminal of the power board 11 is connected to the vehicle DC power supply, and the output interface is connected to the power terminals of the control board 12, the drive board 13, the acquisition board 14, and the communication interface board 15.

[0088] The control board 12 is connected to the drive board 13, the acquisition board 14 and the communication interface board respectively;

[0089] The communication interface board is also connected to the vehicle-mounted brake control unit 00 and each electromagnet unit, and is used to realize data interaction between the vehicle-mounted brake control unit 00 and the electromagnet unit 20 and the control board 12.

[0090] When the eddy current brake controller 10 is working, the power supply board 11 uses the vehicle's DC power supply, which is converted and supplied to the drive board 13, control board 12, acquisition board 14, and communication interface board 15. The power supply is monitored for overvoltage and undervoltage, and the monitoring signals are transmitted to the control board 12 through the acquisition board 14. The drive board 13 receives commands from the control board 12 and drives the first to eighth switches Q8 in the interleaved parallel boost converter circuit 16 and the electromagnet excitation modulation circuit 17. Simultaneously, it collects the status of each switch, including switching status, overvoltage, overcurrent, overtemperature, and communication status. Figure 6 As shown in the circuit diagram, all drive signals issued by the driver board 13 are isolated, and the isolation voltage is not less than U. C1 and U C2 The main circuit data collected by acquisition board 14 includes U in the figure. C1 I C1 U C2 I Q1 I Q2 I Q3 I Q4 I + The corresponding signals of the I- and UT nodes are collected and the data is sent to the control board 12 (the control board 12 controls Q1~Q4 through PWM, controlling the upper I...). c2 Inner ring, U c2 The outer loop, based on feedback, achieves U through PID control. c2 Stable control. IQ1~IQ4 detection, with equalization control added to the current loop to balance the four currents and balance the power of the branches. Regarding the control of the electromagnets, the outer loop controls the electromagnet voltage UT, and the inner loop controls the electromagnet current. PID control is used to control the electromagnet voltage. This is a mature solution. The communication interface board 15 connects to the control board 12, completing communication with the vehicle braking control unit 00 and each electromagnet unit 20. In the above circuit structure, the front stage includes C1, C2, L1, Q1, L2, Q2, L3, Q3, L4, and Q4 in an interleaved parallel structure to boost the vehicle DC power supply voltage. The rear stage includes C2, Q5, Q6, Q7, and Q8 to modulate the excitation current of the electromagnets.

[0091] In an optional embodiment, this application also provides a closed-loop regulation mechanism for the voltage of the supporting capacitor (C2) and the excitation voltage. The mechanism includes: calculating a target value for the supporting capacitor voltage based on the total number of electromagnet units 20 currently in operation, and an excitation voltage reference allocated to the electromagnets, wherein the more electromagnet units 20 currently in operation, the higher the target value of the supporting capacitor voltage; performing closed-loop regulation of the supporting capacitor voltage based on the target value and the measured value of the supporting capacitor voltage; and performing closed-loop regulation of the excitation voltage of the electromagnets based on the excitation voltage reference and the measured value of the excitation voltage.

[0092] The determination of the target value of the supporting capacitor voltage follows the principle of voltage margin, that is, the target voltage level is dynamically adjusted according to the total number of electromagnet units 20 currently in operation. The more electromagnet units 20 are in operation, the higher the required target value of the supporting capacitor voltage needs to be, aiming to reserve sufficient dynamic adjustment margin to cope with the inductor voltage drop demand generated when the excitation current rapidly builds up. This calculation process can be formally expressed as:

[0093]

[0094] In the formula, This represents the target value of the supporting capacitor voltage (the voltage of the second capacitor C2), i.e. The given value; This indicates the total number of electromagnet units 20 that need to be deployed at the current moment. This value comes from the theoretical calculation value of the array calculation module. This represents the target excitation current, corresponding to the desired excitation intensity of the system; This represents the equivalent resistance of a single electromagnet unit 20; This represents the voltage margin coefficient, which can be set to, for example, between 1.1 and 1.3. This coefficient is used to meet the inductor voltage drop requirements during dynamic current regulation. By establishing a positive correlation between the target value of the supporting capacitor voltage and the number of electromagnets engaged, it is possible to effectively avoid the instantaneous drop in the supporting capacitor voltage caused by the simultaneous engagement of a large number of electromagnets, thereby maintaining a constant output voltage of the preceding DC-DC converter.

[0095] Based on this, such as Figure 7 The diagram shown is a block diagram of the closed-loop control system for eddy current braking multi-electromagnet array. The voltage loop error is then calculated. , It is the real-time measured voltage of capacitor C2, that is The measured value.

[0096] The voltage loop output is used as the reference value for the inner current loop. The error of the inner current loop is calculated as follows:

[0097] ,in isI Q1 - I Q4 The measured current value at the location, i.e. The measured value, yes The corresponding target value.

[0098] Current error signal The signal is fed into control board 12, generating corresponding drive pulses to control switching transistors Q1~Q4, ultimately stabilizing the capacitor voltage of C2 for tracking. This provides a stable DC bus voltage for the electromagnet excitation circuit.

[0099] See Figure 7 During the above process, while determining the target value of the supporting capacitor voltage, the eddy current brake controller 10 allocates the excitation voltage reference to the activated electromagnet unit 20. The excitation voltage reference, serving as the given signal for the inner loop control system, directly determines the final voltage level across the electromagnet coil, forming the basis for precise electromagnet control. Subsequently, the eddy current brake controller 10 applies the calculated target value of the supporting capacitor voltage and the excitation voltage reference to the dual-loop regulation strategy, executing the control logic of the outer voltage loop and the inner excitation voltage loop respectively. Specifically, the on / off states of Q5~Q8 directly adjust the excitation voltage of the electromagnet coil, rapidly adjusting the excitation current to achieve a fast braking force response. Voltage closed-loop error calculation: , It is the actual voltage across the electromagnet, that is Measured value The reference voltage across the electromagnet is the setpoint voltage for the electromagnet, and the voltage deviation is... The output is sent to control board 12, which outputs corresponding drive signals to control the on / off states of switching devices Q5~Q8. The relationship between the electromagnet's excitation voltage and current is as follows: D is output from the inner loop of the Q5~Q8 electromagnet voltage, which is the PWM duty cycle output by the regulator; I is the electromagnet current; R is the 20-volt resistor of the electromagnet unit.

[0100] In the above scheme, the closed-loop regulation of the supporting capacitor voltage belongs to the voltage outer loop part of the voltage-current dual inner loop control structure, and is executed by the voltage loop controller inside the eddy current braking controller 10. The acquisition board 14 monitors and acquires the measured value of the supporting capacitor voltage in real time, and the controller in the control board 12 calculates the deviation between the measured value and the target value of the supporting capacitor voltage. The deviation signal is input to the proportional-integral-derivative (PID) controller for calculation, and the output of the PID controller is used as the setpoint of the current inner loop. Based on the setpoint, the duty cycle of the drive signal of the power switches (Q1 to Q4) in the front-stage interleaved parallel structure is adjusted, thereby changing the current flowing through the inductors (L1 to L4), and finally realizing the dynamic adjustment of the supporting capacitor voltage, so that it accurately tracks and stabilizes near the target value, providing a stable and reliable DC bus voltage for the subsequent excitation circuit.

[0101] The closed-loop regulation of the electromagnet excitation voltage is the direct execution link of the electromagnet control, and is executed by the excitation voltage loop controller inside the eddy current brake controller 10. The controller in the control board 12 acquires the measured value of the excitation voltage across the electromagnet in real time and compares it with the allocated excitation voltage reference. Based on the difference between the two, the excitation voltage loop controller generates the corresponding control command, modulating the on and off timing of the subsequent power switches (Q5 to Q8), that is, adjusting the duty cycle of the pulse width modulation (PWM) waveform. This regulation method can quickly change the average voltage applied across the electromagnet coil, thereby precisely controlling the rate of change of the excitation current and achieving rapid response and stable output of the braking torque. The relationship between the electromagnet excitation voltage and current satisfies ,in For PWM duty cycle, This refers to the electromagnet current. This closed-loop regulation ensures that the excitation voltage remains at the set reference value even when the supporting capacitor voltage fluctuates or the load changes, guaranteeing the braking force output accuracy and response speed of the eddy current braking system.

[0102] The aforementioned closed-loop voltage regulation mechanism effectively solves the voltage oscillation problem caused by sudden load changes during the switching of multiple electromagnet arrays. The dynamic boosting strategy of the supporting capacitor voltage and the precise closed-loop control of the excitation voltage work together to create a stable power supply environment, enabling the aforementioned array switching commands to be executed reliably and ensuring the safety and smoothness of the train braking process.

[0103] In another optional embodiment, the method further includes: the eddy current brake controller 10 acquiring the temperature signal, current signal, and fault status information of the electromagnet unit 20 in the engaged state; and determining whether it is necessary to maintain the electromagnet unit 20 in the engaged state based on the temperature signal, current signal, and fault status information.

[0104] During the operation of the eddy current braking system, the eddy current braking controller 10 monitors the electromagnet unit 20 in the activated state in real time to construct a fault identification and protection decision-making mechanism based on multi-dimensional state data. The acquired temperature signal, current signal, and fault state information together constitute a parameter set characterizing the health status of the electromagnet unit 20. Among them, the temperature signal reflects the heat accumulation of the electromagnet coil and magnetic core, which is used to prevent the insulation material from aging or burning due to overheating; the current signal is used to monitor the working status of the excitation circuit to identify short circuit or overload abnormalities; the fault state information serves as a comprehensive status indicator, covering the communication status, power supply status, and physical status of the switching devices of each board (such as the switch driver board 22 and data acquisition board) within the unit. By continuously acquiring the above signals, the eddy current braking controller 10 can grasp the dynamic operating condition of each operating electromagnet unit 20 in real time, providing a data basis for subsequent state maintenance judgment.

[0105] Based on the collected multi-dimensional status data, the eddy current brake controller 10 executes the logic to determine whether to maintain the electromagnet unit 20 in the engaged state. Specifically, it compares the real-time collected temperature signal with a preset temperature threshold. If the detected temperature signal exceeds the preset temperature safety upper limit (e.g., the maximum operating temperature allowed by the coil insulation material), it determines that the electromagnet unit 20 has an overheating risk and must be immediately switched off to prevent thermal runaway. At the same time, it monitors the current signal in real time. If the current signal is abnormal, such as a sharp rise exceeding the preset current overload threshold, or the current is zero under normal instructions but the bus voltage is normal, indicating a circuit break, it determines that the electromagnet unit 20 has an electrical fault. In addition, it analyzes the various status words contained in the fault status information. If it receives fault codes such as abnormal engagement, overvoltage, undervoltage, or communication loss reported from the unit control board 21, it directly identifies them as serious faults.

[0106] When any one or more of the temperature signal, current signal, and fault status information indicate that the electromagnet unit 20 is in an abnormal state, the eddy current brake controller 10 determines that it is not necessary to maintain the electromagnet unit 20 in the engaged state and immediately triggers the protection control logic, outputting a cut-off command to disconnect the excitation circuit of the unit. Conversely, if all signals are within the normal safety threshold range and there is no fault indicator, the electromagnet unit 20 is determined to be in good condition, maintaining its current engaged state and allowing it to continue participating in the output of eddy current braking force. This dynamic judgment mechanism based on multi-dimensional real-time signals achieves refined protection of the electromagnet unit 20, effectively isolating faulty units and preventing local faults from spreading to the entire braking system, thereby ensuring continuous supply of braking force while improving the safety and reliability of system operation.

[0107] In one possible implementation, this application also provides an eddy current braking controller 10 for generating a pool of usable electromagnet units 20 and performing a braking capacity insufficiency determination. This function is a further processing logic after the electromagnet unit 20 is evaluated based on the temperature signal, current signal, and fault state information of the above embodiments. Specifically, the process includes:

[0108] First, a pool of 20 usable electromagnet units is generated based on temperature signals, current signals, and fault status information.

[0109] The eddy current braking controller 10 uses the temperature signal, current signal, and fault status information collected and analyzed in the aforementioned steps to execute the resource pool construction process. The specific construction logic includes: traversing all electromagnet units 20 under the jurisdiction of the eddy current braking system, checking the status flag bit of each unit one by one; if the temperature signal of a certain electromagnet unit 20 does not exceed the preset overheat threshold, the current signal does not show a short circuit or overcurrent phenomenon, and the fault status information shows no communication abnormalities or insulation faults in the hardware circuit, then the identifier (such as ID number) of that electromagnet unit 20 is written into the available electromagnet unit 20 pool; conversely, if any of the above indicators are abnormal, then the electromagnet unit 20 is excluded from the pool. Through this screening mechanism, the available electromagnet unit 20 pool accurately reflects the set of physical entities currently capable of normal excitation operation at any given time, providing a reliable execution basis for subsequent braking force allocation.

[0110] Secondly, when the number of electromagnet units 20 in the available electromagnet unit 20 pool is less than the total number of electromagnet units 20 required to be put in, a warning message indicating insufficient braking capacity is sent to the vehicle braking control unit 00.

[0111] The eddy current brake controller 10 executes supply and demand matching judgment and alarm logic. The total number of electromagnet units 20 required is a theoretical value calculated based on the current train speed, suspension clearance, and the required braking force issued by the on-board brake control unit 00. The controller compares the actual number of units in the available electromagnet unit pool with this total number in real time. If the available number in the pool is sufficient, the normal braking control process is maintained; if the number of electromagnet units 20 in the available electromagnet unit pool is less than the total number of electromagnet units 20 required, it indicates that the current system's healthy hardware resources cannot meet the physical requirements for generating the target braking force. At this time, the eddy current brake controller 10 immediately generates and encapsulates a warning message indicating insufficient braking capacity. This warning message is sent to the on-board brake control unit 00 through the on-board communication network to trigger the degraded operation strategy of the entire vehicle braking system or activate backup braking means (such as friction braking or skid braking), thereby ensuring that the train can still stop safely when emergency braking capacity is limited, avoiding safety hazards caused by insufficient braking force due to blindly executing braking commands.

[0112] The aforementioned technical features work synergistically to achieve real-time perception and quantitative management of the braking system's hardware health status by establishing a dynamically updated pool of 20 available electromagnet units. Furthermore, by comparing available resources with theoretical requirements and triggering alarms, a fault-oriented safety protection mechanism is established. This mechanism can promptly detect capacity gaps and notify the upper-level control system to adjust strategies when a fault occurs in the braking system, thereby ensuring the operational safety and reliability of the eddy current braking system under fault conditions.

[0113] In yet another embodiment, this application also provides a magnetic levitation train, which includes an eddy current braking system. The eddy current braking system is any one of the eddy current braking systems described in the above embodiments.

[0114] The eddy current braking system, a core component of the maglev train's braking system, is integrated into the train's body structure. Specifically, the eddy current braking system is fixed to the train's suspension frames via mechanical mounting interfaces and connected to the train's onboard power system via electrical connection lines to obtain the necessary electrical energy. Simultaneously, the eddy current braking system is connected to the train's onboard braking control unit 00 via a communication bus to receive braking commands and provide system status feedback. During maglev train operation, when the onboard braking control unit 00 issues a braking request, the eddy current braking system dynamically adjusts the number of operational electromagnet units 20 and the excitation current based on parameters such as the train's speed and suspension gap, thereby generating precise and controllable eddy current braking force to achieve efficient and smooth braking of the train.

[0115] Through the above technical solution, this application realizes the application of an eddy current braking system with continuously adjustable, high response speed, and layered safety protection characteristics to maglev trains. Due to the adoption of this eddy current braking system, maglev trains can overcome the problems of graded adjustment of braking force, response lag, and significant influence from speed and clearance in traditional eddy current braking schemes. This significantly improves the braking performance and braking smoothness of the train at different speed ranges, especially at high speeds. Simultaneously, it enhances the safety redundancy and fault tolerance of the braking system, ensuring the operational safety and passenger comfort of the maglev train.

[0116] In another optional embodiment, this application provides a braking system configuration for both sides of a maglev train. This configuration involves equipping each side of the maglev train with an eddy current braking system. Specifically, the two eddy current braking systems are symmetrically distributed on each side of the maglev train.

[0117] The aforementioned maglev train is equipped with an eddy current braking system on each side, meaning that a complete eddy current braking device is independently installed on both the left and right sides of the train's direction of travel. Each eddy current braking system includes an independent eddy current braking controller 10, an array of electromagnet units 20, and corresponding power supply and control circuits, capable of independently receiving commands from the onboard braking control unit 00 and executing braking operations. This dual-side independent configuration design allows the left and right sides to simultaneously generate equal and opposite braking forces during braking, effectively balancing the lateral load on the train body.

[0118] The two eddy current braking systems are symmetrically distributed, meaning that the installation positions of the left and right eddy current braking systems on the car body are mirror images of each other about the longitudinal centerline of the train. Specifically, the distribution range of the left and right eddy current braking systems along the length of the train, their vertical distance from the centerline of the car body, and the arrangement of each electromagnet unit 20 are all consistent. This symmetrical layout ensures that the braking torques generated on both sides can cancel each other out when the system is working, avoiding lateral swaying or attitude deviation of the car body due to lateral braking. For example, when the train performs emergency braking on a straight section, the eddy current braking controllers 10 on both sides receive the same braking command synchronously, control the same number of electromagnet units 20 to work, generate the same braking force, and thus ensure that the car body decelerates smoothly along a straight line.

[0119] Through the above technical solution, this application achieves a balanced dual-sided configuration of the braking system for maglev trains. By employing the technical means of symmetrically setting independent eddy current braking systems on both sides of the train, the technical problems of lateral force imbalance, vehicle body deflection, and increased track side wear that may be caused by single-sided braking are solved, thereby achieving the technical effects of eliminating lateral interference forces, improving safety during high-speed cornering, and extending the service life of the track and electromagnets.

[0120] For ease of description, the above system is described by dividing it into various modules based on their functions. Of course, in implementing this invention, the functions of each module can be implemented in one or more software and / or hardware components.

[0121] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to the descriptions in the method embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0122] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0123] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0124] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0125] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An eddy current braking system, characterized in that, include: Eddy current braking controller and N electromagnet units, where N is a positive integer not less than 2; The N electromagnet units are distributed sequentially between the train's suspension frame along the guide rail direction; The N electromagnet units are connected in series, wherein the negative terminal of the excitation power supply of the upstream electromagnet unit is connected to the positive terminal of the excitation power supply of the downstream electromagnet unit. Each electromagnet unit includes: a first electromagnet, a second electromagnet, a first control switch, and a second control switch; the first end of the first electromagnet is connected to the positive terminal of the excitation power supply of the electromagnet unit through the second control switch, and the second end of the second electromagnet is connected to the second end of the first electromagnet; the first end of the second electromagnet is connected to the positive terminal of the excitation power supply of the electromagnet unit through the first control switch, and the first end of the second electromagnet is also connected to the negative terminal of the excitation power supply; the first electromagnet and the second electromagnet are arranged in the same direction in the first direction, and when the first electromagnet and the second electromagnet are energized, the magnetism at both ends of the electromagnet unit is the same; The eddy current brake controller is used to control the number of electromagnet units engaged after receiving the required braking force sent by the vehicle brake control unit, by controlling the first control switch and the second control switch in each of the electromagnet units, so that the engaged electromagnet units generate the required braking force.

2. The eddy current braking system according to claim 1, characterized in that, N is an even number, wherein N / 2 adjacent electromagnet units are distributed between the first suspension frame and the second suspension frame, and the remaining electromagnet units are distributed between the second suspension frame and the third suspension frame. The first suspension frame, the second suspension frame, and the third suspension frame are three adjacent suspension frames.

3. The eddy current braking system according to claim 1, characterized in that, The electromagnet unit also includes: Unit control board, switch driver board, and data acquisition board; The unit control board is used to acquire the switch control command sent by the eddy current brake controller, forward the switch control command to the switch drive board, acquire the acquisition result of the data acquisition board, and send the acquisition result to the eddy current brake controller. The switch driver board is used to drive the conduction state of the first control switch and the second control switch based on the acquired switch control command; The data acquisition board is used to detect the working status data of the electromagnet unit.

4. The eddy current braking system according to claim 3, characterized in that, The data acquisition board includes: At least one of voltage acquisition board, gap acquisition board, and temperature acquisition board; The voltage acquisition board is used to acquire the voltage across the first electromagnet and the second electromagnet. The gap acquisition plate is used to acquire the gap between the first electromagnet, the second electromagnet and the side rail; The temperature acquisition board is used to acquire the temperature of the first electromagnet and the second electromagnet.

5. The eddy current braking system according to claim 1, characterized in that, The number of electromagnet units engaged is controlled by controlling the first and second control switches in each of the electromagnet units, so that the engaged electromagnet units generate the required braking force, including: Obtain the required braking force sent by the vehicle's braking control unit; The actual value of the total braking force provided by all electromagnet units in the eddy current braking system is obtained. The actual value of the braking force of a single electromagnet unit is calculated based on the train speed, the air gap between the electromagnet and the guide rail, and the excitation current of the electromagnet. Calculate the difference in braking force between the required braking force and the actual braking force value; The number of electromagnet units to be engaged or disengaged is calculated based on the braking force difference and the maximum braking force that a single electromagnet unit can provide. Based on the number of electromagnet units to be put in or cut out, select and control the corresponding electromagnet units to be put in or cut out.

6. The eddy current braking system according to claim 1, characterized in that, The eddy current braking controller is also used for: The target value of the supporting capacitor voltage is calculated based on the total number of electromagnet units currently in operation, as well as the excitation voltage reference allocated to the electromagnets. The higher the total number of electromagnet units currently in operation, the higher the target value of the supporting capacitor voltage. The supporting capacitor voltage is adjusted in a closed loop based on the target value and the measured value of the supporting capacitor voltage, and the excitation voltage of the electromagnet is adjusted in a closed loop based on the excitation voltage reference and the measured value of the excitation voltage.

7. The eddy current braking system according to claim 6, characterized in that, The eddy current braking controller is also used to acquire the temperature signal, current signal and fault status information of the electromagnet unit in the activated state, and to determine whether it is necessary to maintain the electromagnet unit in the activated state based on the temperature signal, current signal and fault status information.

8. The eddy current braking system according to claim 7, characterized in that, The eddy current brake controller is also used to: generate a pool of available electromagnet units based on the temperature signal, current signal and fault status information; and send a warning message of insufficient braking capacity to the vehicle brake control unit when the number of electromagnet units in the pool of available electromagnet units is less than the total number of electromagnet units to be put into operation.

9. A magnetic levitation train, characterized in that, Includes the eddy current braking system according to any one of claims 1-8.

10. The magnetic levitation train according to claim 9, characterized in that, The magnetic levitation train is equipped with an eddy current braking system on each side, and the two eddy current braking systems are symmetrically distributed.

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