Superconducting magnet operation monitoring system and design method

Abstract

This invention discloses a superconducting magnet operation monitoring system and design method, belonging to the field of safety monitoring technology. The system includes a superconducting magnet placed inside a Dewar flask. The superconducting magnet is connected to a subsystem. The vacuum Dewar flask and a molecular pump unit are connected via a bellows, with a solenoid valve mounted on the bellows. The subsystem, power supply, solenoid valve, and molecular pump unit are all connected to a monitoring host. The monitoring host runs system software. The underlying software architecture includes equipment control modules mapped at the software level for the subsystem, power supply, solenoid valve, Dewar flask, and molecular pump unit. By integrating the equipment control modules corresponding to each functional module into the software framework, when the actual physical equipment changes, only simple modifications to the underlying equipment control modules are needed to integrate the new equipment into the system, achieving a universal monitoring system.

Description

Technical Field

[0001] This invention relates to the field of superconducting magnet safety operation monitoring technology, specifically to a superconducting magnet operation monitoring system and design method. Background Technology

[0002] Superconducting magnets are widely used in scientific research, medical fields, and even defense due to their small size, high current density, and zero resistance. There are various types of superconducting magnets, including large superconducting magnets cooled by liquid helium forced flow, closed-loop nuclear magnetic resonance superconducting magnets, small and medium-sized dry magnets cooled by refrigeration mechanisms, small and medium-sized superconducting magnets cooled by liquid helium immersion, and small and medium-sized high-temperature superconducting magnets cooled by liquid nitrogen.

[0003] Superconducting magnets need to operate at 4.5K (low-temperature superconductivity) or 77K (high-temperature superconductivity). During operation, a vacuum system and a cryogenic system are required to maintain the low-temperature vacuum environment. Experiments also require the simultaneous and coordinated operation of power supply systems, quench detection systems, temperature monitoring systems, and other related systems. While there are various types of control equipment for superconducting magnets, these devices can be broadly categorized into eight types: superconducting magnets, cold-shielded Dewars, cryogenic equipment, vacuum equipment, power supply equipment, quench detection equipment, data acquisition equipment, and control system equipment.

[0004] To address the operational requirements of superconducting magnets, many system solutions have been proposed, such as:

[0005] (1) The invention patent application with publication number CN110989359A proposed "a control system based on deep learning", which uses the model after deep learning to control the operation of a superconducting magnet. However, this method ignores a problem: deep learning requires a large amount of normal and quench failure operation data as sample data for model training. However, the superconducting magnet has a large amount of stored energy during operation, and each quench failure may damage the magnet. Moreover, the operation of the superconducting magnet is generally not allowed to quench or should be avoided as much as possible. Therefore, it is difficult to obtain actual sample data and requires the control system to have a higher safety margin.

[0006] (2) The article “Development of a temperature monitoring system for superconducting magnets of the EAST device” published in Engineering Technology II on May 31, 2021, proposed a low-temperature monitoring system for superconducting magnets based on PLC and Lakeshore equipment. However, this system is only applicable to low-temperature monitoring of the EAST device and is not applicable to other magnet systems.

[0007] (3) The article "Design of Monitoring System for ECRH Superconducting Magnet Device" published in the journal Nuclear Electronics and Detection Technology on June 20, 2017, proposed a monitoring and control system that utilizes computer network technology and fiber optic isolation technology. The interface is designed using the graphical programming software LabVIEW, which allows for the setting of parameters such as superconducting magnet current and voltage, and remote real-time monitoring of the status of the superconducting magnet and its hardware. However, this system is only applicable to the control of the ECRH device and lacks universality.

[0008] (4) The article “Design and Research of Diagnostic Control System for CSMC Magnet Test Platform” published in Engineering Technology II on June 1, 2020 proposes a distributed large superconducting magnet operation monitoring system based on EPICS architecture. However, due to the complexity of the system, it is not suitable for the operation control of small and medium-sized superconducting magnets.

[0009] In summary, the current superconducting magnet operation monitoring system has two problems: (1) The system is part of the superconducting magnet operation monitoring system or is the system itself. The system is customized according to the superconducting magnet and has good matching with its target device, but it does not have universality; (2) The modules in the system are heavily coupled, the modules are not replaceable, and the compatibility with new equipment is poor. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to provide a superconducting magnet operation monitoring system with good versatility.

[0011] The present invention solves the above-mentioned technical problems through the following technical means:

[0012] On one hand, the present invention proposes a superconducting magnet operation monitoring system, the system comprising: a superconducting magnet placed inside a vacuum Dewar, the superconducting magnet being connected to a subsystem and a power supply, the vacuum Dewar being connected to a molecular pump unit via a bellows, the bellows being equipped with an electromagnetic vacuum valve, and the subsystem, the power supply, the electromagnetic vacuum valve, and the molecular pump unit being connected to a monitoring host.

[0013] The monitoring host runs system software. The upper layer of the system software architecture is the user control interface, the middle layer includes the device control module, and the lower layer includes the subsystem, the power supply, the electromagnetic vacuum valve, the vacuum Dewar, and the molecular pump unit. The subsystem control module, power supply control module, electromagnetic valve control module, vacuum unit control module, and molecular pump control module are mapped to the subsystem at the software level.

[0014] This invention divides the actual operating monitoring system into functional modules, maps the actual operating physical system to the software level, and obtains the device modules corresponding to each functional module as the bottom layer of the system software. The user interface is used as the top layer of the software framework, and the background functional modules are used as the middle layer. The integrated software framework corresponds to the monitoring system. When the actual operating physical equipment changes, only simple modifications are needed to the device control module corresponding to the bottom physical equipment to integrate the new equipment into the system, thus realizing the universality of the superconducting magnet operation monitoring system.

[0015] Furthermore, the subsystem includes a quench detection system, a data acquisition system, and a cryogenic refrigerator. The quench detection system and the data acquisition system are respectively connected to the superconducting magnet via cables. The cryogenic refrigerator is connected to the superconducting magnet via a cooling helium inlet / outlet pipe. The power supply is connected to the superconducting magnet via a current lead.

[0016] The subsystem control module includes a quench detection and protection module, a data acquisition and control module, and a cooling control module.

[0017] Furthermore, a message queue module is provided between the middle layer and the bottom layer of the system software. The message queue module is used to parse the message instructions sent by the modules in the middle layer into operation instructions for the device modules in the bottom layer.

[0018] Furthermore, the intermediate layer also includes a data acquisition module, a fault diagnosis module, and an operation log module.

[0019] Furthermore, the control module includes:

[0020] The first control unit is used to send instructions to the solenoid valve control module so that the solenoid valve control module controls the solenoid vacuum valve to open.

[0021] The second control unit is used to send commands to the vacuum unit control module so that the vacuum unit control module controls the mechanical pump to be turned on;

[0022] The parameter acquisition unit is used to acquire the vacuum degree parameters of the vacuum Dewar.

[0023] The third control unit is used to send instructions to the molecular pump control module according to the vacuum parameter, so that the molecular pump control module controls the opening of the molecular pump unit;

[0024] The fourth control unit is used to send instructions to the refrigeration control module so that the refrigeration control module controls the opening of the cryogenic refrigerator.

[0025] Furthermore, the formula for calculating the vacuum degree parameter is as follows:

[0026]

[0027] Where δt=t2-t1, Pvc(t1) is the vacuum level parameter of the vacuum Dewar at time t1. Let t1 be the rate of change of vacuum level, and Pvc(t2) be the vacuum level parameter of the vacuum Dewar at time t2.

[0028] The third control unit is used to ensure that Pvc(t2) >= Pv critical At that time, a command is sent to the molecular pump control module to cause the molecular pump control module to control the opening of the molecular pump unit, Pv critical This represents the ultimate vacuum level during normal operation.

[0029] Furthermore, the data acquisition module includes:

[0030] The first acquisition unit is used to acquire the vacuum level of the vacuum Dewar using the vacuum unit control module;

[0031] The second acquisition unit is used to acquire the temperature of the lower end of the superconducting magnet using the cooling control module.

[0032] The control module also includes:

[0033] The judgment unit is used to allow superconducting state testing when the vacuum degree is greater than 9E-4Pa and the temperature at the lower end of the superconducting magnet is lower than 5K.

[0034] The fourth control unit is used to send instructions to the power control module to cause the power supply to output current I;

[0035] The monitoring unit is used to monitor the terminal voltage of the superconducting magnet and cut off the power supply when the superconducting magnet is in a non-superconducting state.

[0036] On the other hand, the present invention also proposes a design method for a superconducting magnet operation monitoring system, the method comprising:

[0037] The superconducting magnet operation monitoring system is divided into functional modules, resulting in multiple functional modules.

[0038] The behaviors implemented by the multiple functional modules are abstracted into methods, and the parameters of the multiple functional modules are abstracted into attributes;

[0039] The device control instructions corresponding to the multiple functional modules are encapsulated into their corresponding methods, which serve as the underlying modules of the software framework of the superconducting magnet operation monitoring system.

[0040] The software framework is integrated using the underlying module, upper layer, and middle layer. The middle layer is the background working module, and the upper layer is the user interface.

[0041] Furthermore, the intermediate layer and the underlying module communicate through a message queue module.

[0042] The advantages of this invention are:

[0043] (1) This invention divides the actual operating monitoring system into functional modules and maps the actual operating physical system at the software level to obtain the device modules corresponding to each functional module as the bottom layer of the system software. The user interface is used as the top layer of the software framework, and the background functional modules are used as the middle layer. The software framework corresponding to the monitoring system is integrated. When the actual operating physical equipment changes, only simple modifications are needed to the device control module corresponding to the bottom physical equipment to integrate the new equipment into the system, thus realizing the universality of the superconducting magnet operation monitoring system.

[0044] (2) This invention integrates a message queue module between the middle layer and the bottom layer of the system software framework. The message queue module is used to parse the message instructions sent by the background function module in the middle layer into operation instructions for the device control module in the bottom layer. The message queue module decouples the upper layer and the bottom layer of the system software framework. The specific control instructions of the upper layer system are encapsulated into string commands and passed to the designated device control module through the message queue module. The device control module parses the corresponding command and calls the corresponding method to achieve the final control of the physical device. This solves the problems of severe coupling between modules in the system, lack of module replaceability, and poor compatibility with new devices.

[0045] (3) In order to achieve the operating environment conditions of the superconducting magnet, a long vacuuming and cooling time is required. This invention proposes a one-click cooling function, which can automatically perform vacuuming and cooling and superconducting state testing on the superconducting magnet system without manual intervention, greatly saving labor and time costs.

[0046] (4) In order to save energy, the present invention will shut down the vacuum unit after the vacuum level reaches the standard during the operation of the magnet. When the vacuum level rises to the set threshold, the vacuum unit will be turned on again to perform vacuuming operation, so as to realize automatic control of the vacuum level of the superconducting magnet Dewar.

[0047] (5) By monitoring the compensated terminal voltage, the power supply can be quickly cut off when the magnet is in a non-superconducting state, thereby reducing the temperature rise of the magnet.

[0048] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0049] Figure 1This is a structural diagram of the superconducting magnet operation monitoring system in the first embodiment of the present invention;

[0050] Figure 2 This is a schematic diagram of the functional modules of the system software framework in the first embodiment of the present invention;

[0051] Figure 3 This is a flowchart of the one-click cooling process in the first embodiment of the present invention;

[0052] Figure 4 This is a flowchart of the vacuum control process in the first embodiment of the present invention;

[0053] Figure 5 This is a flowchart of the superconducting state test in the first embodiment of the present invention;

[0054] Figure 6 This is a flowchart of the design method for the superconducting magnet operation monitoring system in the second embodiment of the present invention;

[0055] Figure 7 This is an overall flowchart of the design method for a superconducting magnet operation monitoring system in the second embodiment of the present invention. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0057] like Figures 1 to 2 As shown in the figure, an embodiment of the present invention proposes a superconducting magnet 1 operation monitoring system. The system includes: a superconducting magnet 1 placed in a vacuum dewar 2, the superconducting magnet 1 being connected to a subsystem and a power supply 6, the vacuum dewar 2 being connected to a molecular pump unit 7 via a bellows 14, the bellows 14 being equipped with an electromagnetic vacuum valve 9, and the subsystem, the power supply 6, the electromagnetic vacuum valve 9, and the molecular pump unit 7 being connected to a monitoring host 8.

[0058] The monitoring host 8 runs system software. The upper layer of the software system architecture is the user control interface, the middle layer includes the device control module, and the lower layer includes the subsystem, the power supply 6, the electromagnetic vacuum valve 9, the vacuum Dewar 2, and the molecular pump unit 7. The subsystem control module, power supply control module, electromagnetic valve control module, vacuum unit control module, and molecular pump control module are mapped at the software level.

[0059] In this embodiment, the actual operating monitoring system is divided into functional modules, and the actual operating physical system is mapped at the software level to obtain the device modules corresponding to each functional module, which serve as the bottom layer of the system software. The user interface is used as the top layer of the software framework, and the background functional modules are used as the middle layer. The software framework corresponding to the monitoring system is integrated. When the actual operating physical device changes, only simple modifications are needed to the device control module corresponding to the bottom-level pre-physical device to integrate the new device into the system, thus realizing the universality of the superconducting magnet 1 operation monitoring system.

[0060] In one embodiment, the subsystem includes a quench detection system 3, a data acquisition system 4, and a cryogenic refrigerator 5. The quench detection system 3 and the data acquisition system 4 are respectively connected to the superconducting magnet 1 via cables. The cryogenic refrigerator 5 is connected to the superconducting magnet 1 via a cooling helium inlet / outlet pipe 12. The power supply 6 is connected to the superconducting magnet 1 via a pure copper current lead 13. The subsystem control module includes a quench detection protection module, a data acquisition control module, and a refrigeration control module.

[0061] The quench detection system is used to measure the rate of change of voltage and current at the voltage terminal of the superconducting magnet connector in real time using a voltage probe. When the voltage at a certain part after compensation exceeds 1V within 200ms, it is determined that the magnet has quenched. At this time, the quench detection system will send an alarm signal to the power supply system to notify the power supply system to cut off the power and connect the protection circuit.

[0062] The data acquisition system is used to monitor the temperature of various components inside the Dewar. It measures the temperature of the magnet and refrigerated parts using a PT100 or Cernox low-temperature temperature sensor, converts the temperature signal into an analog voltage signal within ±1V, and then converts the analog voltage signal into a digital signal through the analog-to-digital converter module of the data acquisition system. Finally, through a specific conversion formula, the digital signal is converted into the actual temperature, thereby realizing the monitoring of the temperature of each component.

[0063] It should be noted that the subsystem structure in this embodiment is only an example, and those skilled in the art can set up specific subsystem structures according to actual needs.

[0064] Specifically, the quench detection system 3 is connected to the superconducting magnet 1 via the quench detection signal cable 10, the data acquisition system 4 is connected to the superconducting magnet 1 via the data acquisition signal cable 11, and the monitoring host 8 is connected to the power supply 6, the molecular pump unit 7, the quench detection system 3, the data acquisition system 4, the cryogenic refrigerator 5, and the electromagnetic vacuum valve 9 via the digital communication cable 15. The monitoring system requires coordination and cooperation between the various modules to complete the experimental operation of the superconducting magnet 1.

[0065] In one embodiment, a message queue module is provided between the middle layer and the bottom layer of the system software. The message queue module is used to parse message instructions sent by the modules in the middle layer into operation instructions for the device modules in the bottom layer.

[0066] In this embodiment, a message queue is used to decouple the upper and lower layers of the system. The specific control instructions of the upper layer system are encapsulated into string commands and passed to the designated module through the message queue. The module parses the corresponding command and calls the corresponding method to achieve the final control of the physical device.

[0067] The middle layer and the bottom layer are decoupled through message queues, thus maintaining the independence between the two layers. When physical devices change, only simple modifications are needed to the corresponding device modules at the bottom layer to integrate the new devices into the monitoring system.

[0068] In one embodiment, the intermediate layer further includes a data acquisition module, a fault diagnosis module, and an operation log module.

[0069] The data acquisition module is used to collect various parameters such as temperature, voltage, vacuum, molecular pump speed, and inlet and outlet water temperature of the refrigeration unit during the operation of the magnet. On the one hand, it provides users with real-time and historical operating data services, and on the other hand, it provides data support for fault analysis and maintenance.

[0070] The fault diagnosis module is used to evaluate the magnet's operating status in real time by extracting historical and real-time data from the data acquisition module. For example, if the vacuum level gradually increases and the molecular pump starts more frequently during magnet operation, it indicates a problem with the Dewar seal, requiring the user to be alerted for maintenance. The module can also determine whether the refrigerator's operating efficiency has decreased by monitoring the magnet's cooling rate, thus prompting the user to inspect the refrigerator.

[0071] The operation log module is used to record user operations and automatic system operations, which helps maintenance engineers diagnose the fault when the equipment malfunctions.

[0072] It should be understood that the background function modules set up in the middle layer are not limited to the function modules described in this embodiment, and this embodiment does not make specific limitations.

[0073] In one embodiment, the control module includes:

[0074] The first control unit is used to send instructions to the solenoid valve control module so that the solenoid valve control module controls the solenoid vacuum valve 9 to open.

[0075] The second control unit is used to send commands to the vacuum unit control module so that the vacuum unit control module controls the mechanical pump to be turned on;

[0076] The parameter acquisition unit is used to acquire the vacuum degree parameters of the vacuum Dewar 2;

[0077] The third control unit is used to send instructions to the molecular pump control module according to the vacuum parameter, so that the molecular pump control module controls the opening of the molecular pump unit 7;

[0078] The fourth control unit is used to send instructions to the refrigeration control module so that the refrigeration control module controls the opening of the cryogenic refrigerator 5.

[0079] like Figure 3 As shown, the monitoring system features a one-button cooling mode. The control module in the middle layer of the system software framework first controls the opening of the solenoid valve control module between the vacuum Dewar 2 and the vacuum pump, and then starts the mechanical pump to perform primary vacuuming of the Dewar. Since the vacuum level is poor at this stage, directly starting the molecular pump unit 7 would damage the molecular pump. According to the system design, the vacuum level of the Dewar is automatically monitored at this time. When the vacuum level is higher than 10E-2Pa, the control module controls the molecular pump unit 7 to perform secondary vacuuming through the molecular pump control module. When the vacuum level is detected to be higher than 10E-4Pa, it indicates that the vacuum level of the Dewar is good and the cooling stage can begin. At this time, the monitoring host 8 remotely controls the cryogenic refrigerator 5 to start via digital signals and monitors the inlet and outlet pressures and cooling water temperature of the refrigerator. After entering the cooling stage, the monitoring system uses the data acquisition module to monitor and record the temperature of the superconducting magnet 1 and the cold screen, and judges the state of the superconducting magnet 1 based on the temperature. If the temperature reaches the required operating temperature for the magnet, the superconducting state test process begins. If the superconducting state test fails, cooling continues, and the superconducting state test is repeated after a certain interval. If the superconducting state test passes, it means the magnet has entered the superconducting state, and the one-click cooling process for the magnet is complete.

[0080] To achieve the operating environment conditions of the superconducting magnet 1, a long vacuuming and cooling process is required. This embodiment proposes a one-click cooling function, which can automatically perform vacuuming and cooling and superconducting state testing on the superconducting magnet 1 system without manual intervention, greatly saving labor and time costs.

[0081] In one embodiment, the formula for calculating the vacuum degree parameter is:

[0082]

[0083] Where δt=t2-t1, Pvc(t1) is the vacuum level parameter of the vacuum Dewar at time t1. Let t1 be the rate of change of vacuum level, and Pvc(t2) be the vacuum level parameter of the vacuum Dewar at time t2.

[0084] The third control unit is used to calculate the vacuum level at time t2 in advance at time t1, when Pvc(t2)>=Pv critical At that time, a command is sent to the molecular pump control module to cause the molecular pump control module to control the opening of the molecular pump unit 7, Pv critical This represents the ultimate vacuum level during normal operation.

[0085] It should be noted that when the Dewar flare is well-sealed, the vacuum level changes very slowly, and can be considered to change linearly over an hour. In this case, Pvc(t2) ≈ Pv(t2), where Pv(t2) is the actual vacuum level of the Dewar flare. Even when the sealing condition is relatively poor, Pvc(t2) > Pv(t2), meaning that Pvc(t2) has a certain margin relative to Pv(t2). Therefore, Pvc(t2) is used for control. Let the ultimate vacuum level during normal operation be Pv. critical When Pvc(t2) is calculated to be greater than or equal to Pv at time t1 critical At this time, the molecular pump unit 7 is started.

[0086] Since the molecular pump unit 7 first needs to evacuate its internal controls, the solenoid valve can only be opened when the vacuum level inside and in the pipeline reaches the Dewar vacuum level. Therefore, the Dewar vacuum is evacuated. Assuming the internal space of the molecular pump and pipeline is small, the evacuation time is within 10 minutes, meaning the molecular pump needs to be started 10 minutes in advance, δt is set to 600 seconds. During actual operation, the system will predict the vacuum level 600 seconds later based on the current vacuum level and the rate of vacuum change. If the vacuum level 600 seconds later does not meet the operational requirements, the molecular pump unit 7 needs to be started immediately to prepare for the evacuation task.

[0087] It should be noted that, to conserve energy, during the operation of superconducting magnet 1, the vacuum unit will be shut down once the Dewar vacuum level reaches the target. Once the vacuum level rises to the set threshold, the vacuum unit will be restarted for evacuation. The specific workflow is as follows: Figure 4 As shown, once the magnet vacuum level reaches the required level, the monitoring system will automatically enter the vacuum maintenance phase. At this time, the electromagnetic vacuum valve 9 will close to ensure the vacuum level inside the Dewar. The monitoring system will continuously monitor the vacuum level parameters. When the vacuum level parameters approach the set threshold, the system will control the mechanical pump to start and monitor the vacuum level of the vacuum bellows 14. When the vacuum level of the vacuum bellows 14 reaches 10E-2 Pa, the system will control the molecular pump to start. When the vacuum level of the vacuum bellows 14 is close to that of the magnet Dewar, the electromagnetic vacuum valve 9 between the Dewar and the bellows 14 will open. When the Dewar vacuum level reaches 5E-4 Pa, the electromagnetic vacuum valve 9 between the Dewar and the bellows 14 will close, and the molecular pump will also be turned off. After the molecular pump stops rotating, the mechanical pump will be turned off. This cycle repeats until the experiment ends.

[0088] In this embodiment, the control module controls the actual physical vacuum unit's automatic control function through the vacuum unit control module. After the system's vacuum level reaches the standard, the vacuum unit is automatically shut down. The module also predicts the changes in vacuum level based on the calculation formula and automatically starts the vacuum unit at the appropriate time. This simplifies user operation and significantly reduces energy consumption during experimental operation.

[0089] In one embodiment, the data acquisition module includes:

[0090] The first acquisition unit is used to acquire the vacuum degree of the vacuum Dewar 2 using the vacuum unit control module;

[0091] The second acquisition unit is used to acquire the temperature of the lower end of the superconducting magnet 1 using the cooling control module;

[0092] The control module also includes:

[0093] The judgment unit is used to allow superconducting state testing when the vacuum degree is greater than 9E-4Pa and the temperature at the lower end of the superconducting magnet 1 is lower than 5K.

[0094] The fourth control unit is used to send instructions to the power control module to cause the power supply 6 to output current I;

[0095] The monitoring unit is used to monitor the terminal voltage of the superconducting magnet 1 and cut off the power supply 6 when the superconducting magnet 1 is in a non-superconducting state.

[0096] It should be noted that, as Figure 5 As shown, when superconducting magnet 1 enters the superconducting state, its resistance becomes zero. At this time, the resistance across the magnet is only the very small resistance of the superconducting junction, which is typically below 10E-8Ω. If a 2A current is applied to superconducting magnet 1 and the terminal voltage is below 200mV, it indicates that the magnet has entered the superconducting state. However, since superconducting magnet 1 is a large energy storage inductor with an inductance ranging from 0.1-10H, the terminal voltage during excitation... If the excitation rate is too fast, the generated induced terminal voltage will exceed the voltage judgment threshold, causing misjudgment of the magnet's state. Therefore, this embodiment monitors the rate of change of current. Given the magnet's inductance, when the current changes, the system automatically calculates the induced electromotive force (EMF), subtracts the calculated EMF from the directly measured terminal voltage, and then compares it with the voltage threshold to assess whether the magnet has entered the superconducting state. The specific implementation workflow is as follows:

[0097] When the superconducting state test is initiated, the monitoring system first determines whether the Dewar vacuum level and the temperature at the lower end of the superconducting magnet 1 meet the requirements. If the vacuum level is higher than 9E-4 Pa and the temperature at the lower end of the magnet is lower than 5K, the superconducting state test is permitted. At this time, the monitoring system controls the actual power supply 6 to output a current with a maximum value not exceeding 2A via the power control module, and monitors the terminal voltage of the superconducting magnet 1. If the superconducting magnet 1 is in the superconducting state, the compensated terminal voltage should be very small, and the voltage change du should be approximately equal to the loop resistance R multiplied by the current change d. i Normally, monitoring the voltage change (du) is sufficient. By monitoring the compensated terminal voltage, the power supply can be quickly cut off when the magnet is in a non-superconducting state, thereby reducing the magnet's temperature rise.

[0098] In addition, such as Figure 6 As shown in the figure, this invention also proposes a design method for a superconducting magnet operation monitoring system, the method comprising the following steps:

[0099] S10. The superconducting magnet operation monitoring system is divided into functional modules, resulting in multiple functional modules;

[0100] S20. Abstract the behaviors implemented by the multiple functional modules into methods, and abstract the parameters of the multiple functional modules into attributes;

[0101] S30. Encapsulate the device control instructions corresponding to the multiple functional modules into their corresponding methods, and use them as the underlying modules of the software framework of the superconducting magnet operation monitoring system.

[0102] S40. The software framework is integrated using the underlying module, upper layer and middle layer, wherein the middle layer is the background working module and the upper layer is the user operation interface.

[0103] In this embodiment, the first step is to divide the designed monitoring system into functional modules, for example, dividing the system into... Figure 1The multiple modules shown should be divided according to the principle of independence, meaning each module has its own core function and independent behavior, and there should be no overlap between modules. The second step is to abstract each module, abstracting the behaviors that a module can perform into methods. The input parameters of a method are the indicators or parameters required for the module to execute the action, and the return value is the actual return indicator or parameter of the system after the module executes the action. Specific parameters possessed by a module are abstracted into attributes, which can be public or private. When a module wants to expose a certain parameter, the attribute is set to a public attribute; otherwise, it is set to a private attribute. The third step is to perform concrete implementation operations on the abstracted module objects, that is, to encapsulate the actual equipment control instructions into the object's methods. The actual equipment can be a PLC, temperature controller, temperature monitor, power supply, level gauge, refrigeration unit, etc. When a method is called, the module object sends the corresponding control instructions to the corresponding equipment, thereby controlling the equipment's operation. The fourth step is system integration, which integrates the aforementioned bottom-level modules with the upper-level and middle-level modules. The upper-level modules can be designed according to specific needs without worrying about the development of the underlying system. The upper-level system can be a regular user interface, a comprehensive measurement and control platform, or a big data automated control system, etc. The middle-level modules are back-end functional modules, which can be designed according to actual needs.

[0104] In one embodiment, such as Figure 7 As shown, the intermediate layer and the underlying module communicate through a message queue module.

[0105] This embodiment decouples the upper and lower layers of the system through message queues. The specific control instructions of the upper-layer system are encapsulated into string commands and passed to the designated modules through message queues. The modules parse the corresponding commands and call the corresponding methods. Finally, the physical devices can be controlled by sending data to the lower-layer modules through network message queues or local message queues using agreed-upon control commands.

[0106] It should be noted that the following example illustrates the design process of a monitoring system:

[0107] Taking a vacuum unit as an example, its functions include vacuum level monitoring, mechanical pump start / stop, molecular pump start / stop, molecular pump speed adjustment, and molecular pump operating status query. The vacuum unit can be considered an object with attributes including vacuum level and operating status, and methods including mechanical pump start, mechanical pump stop, molecular pump start, molecular pump stop, and molecular pump speed adjustment. When the monitoring system needs to start the molecular pump, it simply calls the "Molecular Pump Start" method of the vacuum unit object.

[0108] Add the actual control instructions for the vacuum unit to the method. For example, the molecular pump start instruction is "02062000000883FF", and the communication protocol is Modbus TCP. Then, you only need to call the Modbus TCP communication program in the molecular pump start method to send the "02062000000883FF" instruction to the vacuum unit. At this point, the object design of the vacuum unit control module is completed, and communication control with the actual molecular pump is realized. Then the upper-level system can control the vacuum unit through the vacuum unit control module.

[0109] However, if the upper-level system directly calls the lower-level method, it will also cause coupling between systems. A decoupling module, the message queue, is implemented between the upper and lower layers. The upper-level module only needs to send message commands to the message queue. Through the message queue module, the commands are parsed into operation instructions for the device objects. For example, when the system needs to start the molecular pump, the upper-level control system first sends the command "VacuuSystem.OpenMolecularPump" to the message queue through the control module. The message queue then parses this command, first using the "." symbol to segment the command, obtaining the target system name "VacuuSystem" and the control command "OpenMolecularPump" for the target system. The message queue then forwards the control command to the vacuum unit control module, which calls its method to start the molecular pump, thus ultimately achieving the task of starting the molecular pump. Other subsystems are designed in a similar way, and will not be elaborated further here.

[0110] Once all subsystem objects have been abstracted and encapsulated, the upper-level system can control each module through message queues, thereby achieving overall system coordination and control. When any subsystem or device changes, only minor modifications to the methods within the object are needed to re-adapt.

[0111] In one embodiment, the one-button cooling function of the monitoring system is achieved by the control system coordinating the vacuum unit, chiller, solenoid valve, vacuum gauge, and control system. The control principle is as follows: the control system sends an "OPEN" string command to the solenoid valve control module via the equipment control module. The solenoid valve control module controls the PLC's digital I / O port, setting the digital level to a high level, at which point the electromagnetic vacuum valve opens. Then, the control module sends a "MechanicalPumpOpen" string command to the vacuum unit control module. The vacuum unit control module, based on Modbus TCP commands, sends a hexadecimal control command "020620000007C3FB" to the vacuum unit via the network port. Upon receiving the command, the vacuum unit starts the mechanical pump. The vacuum level is detected by a vacuum gauge, which, as part of the vacuum unit, is controlled by the vacuum unit control module. The vacuum unit control module sends the command "02031000000440FA" to the vacuum unit every 0.5 seconds, receives its return value, parses it, and obtains the vacuum parameters. When the molecular pump needs to be started, the control module sends the command "OpenMolecularPump" to the vacuum unit control module, which in turn sends the command "02062000000883FF" to the vacuum unit. At this point, the molecular pump begins operation. When the refrigerator needs to be started, the control module sends the command "OpenCryoRefrigerator" to the refrigerator via a message queue. Upon receiving the command, the refrigerator control module controls the PLC's digital I / O port to set the refrigerator control I / O digital level port to a high bit, at which point the refrigerator begins operation.

[0112] The design method for the superconducting magnet monitoring system proposed in this embodiment abstracts each subsystem and encapsulates each subsystem into a control module. Control of each subsystem is achieved by sending commands to the control module. A message queue is used to decouple the upper and lower layers of the system. The upper-layer system development and runtime do not require knowledge of the specific implementation of the lower-layer system, and vice versa, allowing independent development and operation of both layers. When adding or replacing subsystems or devices, if the device control module object already exists, the existing model can be directly copied. If it is a new module device, control of the new device can be achieved by adding or modifying the control module. When building a new superconducting magnet monitoring system, only the control instructions of the underlying control module need to be modified to achieve system portability. Therefore, the system has excellent scalability and portability.

[0113] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0114] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0115] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A superconducting magnet operation monitoring system, characterized in that, The system includes: a superconducting magnet placed inside a vacuum Dewar, the superconducting magnet being connected to a subsystem and a power supply, the vacuum Dewar being connected to a molecular pump unit via a bellows, the bellows being equipped with an electromagnetic vacuum valve, and the subsystem, the power supply, the electromagnetic vacuum valve, and the molecular pump unit being connected to a monitoring host. The monitoring host runs system software. The upper layer of the system software architecture is the user control interface, the middle layer includes the device control module, and the lower layer includes the subsystem, the power supply, the electromagnetic vacuum valve, the vacuum Dewar, and the molecular pump unit. The subsystem control module, power supply control module, electromagnetic valve control module, vacuum unit control module, and molecular pump control module are mapped to the subsystem at the software level.

2. The superconducting magnet operation monitoring system as described in claim 1, characterized in that, The subsystem includes a quench detection system, a data acquisition system, and a cryogenic refrigerator. The quench detection system and the data acquisition system are respectively connected to the superconducting magnet via cables. The cryogenic refrigerator is connected to the superconducting magnet via a cooling helium inlet / outlet pipe. The power supply is connected to the superconducting magnet via a current lead. The subsystem control module includes a quench detection and protection module, a data acquisition and control module, and a cooling control module.

3. The superconducting magnet operation monitoring system as described in claim 1, characterized in that, A message queue module is provided between the middle layer and the bottom layer of the system software. The message queue module is used to parse the message instructions sent by the modules in the middle layer into operation instructions for the device modules in the bottom layer.

4. The superconducting magnet operation monitoring system as described in claim 2, characterized in that, The intermediate layer also includes a data acquisition module, a fault diagnosis module, and an operation log module.

5. The superconducting magnet operation monitoring system as described in claim 4, characterized in that, The device control module includes: The first control unit is used to send instructions to the solenoid valve control module so that the solenoid valve control module controls the solenoid vacuum valve to open. The second control unit is used to send commands to the vacuum unit control module so that the vacuum unit control module controls the mechanical pump to be turned on; The parameter acquisition unit is used to acquire the vacuum degree parameters of the vacuum Dewar. The third control unit is used to send instructions to the molecular pump control module according to the vacuum parameter, so that the molecular pump control module controls the opening of the molecular pump unit; The fourth control unit is used to send instructions to the refrigeration control module so that the refrigeration control module controls the opening of the cryogenic refrigerator.

6. The superconducting magnet operation monitoring system as described in claim 5, characterized in that, The formula for calculating the vacuum degree parameter is as follows: Where δt=t2-t1, Pvc(t1) is the vacuum level parameter of the vacuum Dewar at time t1. Let t1 be the rate of change of vacuum level, and Pvc(t2) be the vacuum level parameter of the vacuum Dewar at time t2. The third control unit is used to ensure that Pvc(t2) >= Pv critical At that time, a command is sent to the molecular pump control module to cause the molecular pump control module to control the opening of the molecular pump unit, Pv critical This represents the ultimate vacuum level during normal operation.

7. The superconducting magnet operation monitoring system as described in claim 4, characterized in that, The data acquisition module includes: The first acquisition unit is used to acquire the vacuum level of the vacuum Dewar using the vacuum unit control module; The second acquisition unit is used to acquire the temperature of the lower end of the superconducting magnet using the cooling control module. The control module also includes: The judgment unit is used to allow superconducting state testing when the vacuum degree is greater than 9E-4Pa and the temperature at the lower end of the superconducting magnet is less than 5K. The fourth control unit is used to send instructions to the power control module to cause the power supply to output current I; The monitoring unit is used to monitor the terminal voltage of the superconducting magnet and cut off the power supply when the superconducting magnet is in a non-superconducting state.

8. A design method for a superconducting magnet operation monitoring system, characterized in that, The method includes: The superconducting magnet operation monitoring system is divided into functional modules, resulting in multiple functional modules. The behaviors implemented by the multiple functional modules are abstracted into methods, and the parameters of the multiple functional modules are abstracted into attributes; The device control instructions corresponding to the multiple functional modules are encapsulated into their corresponding methods, which serve as the underlying modules of the software framework of the superconducting magnet operation monitoring system. The software framework is integrated using the underlying module, upper layer, and middle layer. The middle layer is the background working module, and the upper layer is the user interface.

9. The design method of the superconducting magnet operation monitoring system as described in claim 8, characterized in that, The intermediate layer and the underlying module communicate with each other through a message queue module.

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