A superconducting reactor on-line inspection method and device for loss of field detection

Abstract

The application relates to a superconducting reactor charged inspection method and device for quench detection, and belongs to the field of reactor maintenance. The method comprises the following steps: during the operation of a superconducting reactor to be detected, a magnetic sensor is attached to the outer wall of the superconducting reactor to perform real-time measurement of a magnetic field, and the magnetic sensor is moved along the direction with the largest magnetic field increasing gradient to locate the maximum value position of the magnetic field in each region of the superconducting reactor, so that preliminary estimation of the quench position is realized; when the preliminary estimation indicates that the quench position exists, the magnetic field is measured by arranging magnetic sensors at multiple positions of the superconducting reactor, and the electromagnetic coefficient matrix is determined according to the superconducting coil parameters of the superconducting reactor and the positions of the magnetic sensors, so that the current size of the superconducting coil group corresponding to the branch at the position of the magnetic sensor is calculated, thereby realizing accurate positioning of the quench position. Compared with the prior art, the application can realize detection with fewer magnetic sensors, can greatly reduce the cost, and can reduce the installation complexity and potential hidden dangers.

Description

Technical Field

[0001] This invention relates to the field of live inspection technology for superconducting reactors, and in particular to a method and apparatus for live inspection of superconducting reactors for quench detection. Background Technology

[0002] like Figure 2 As shown, a superconducting reactor consists of three main parts: the equipment body, the refrigeration system, and the detection and protection system. The equipment body includes superconducting windings, bushings, solid insulation, liquid nitrogen, and a Dewar (i.e., a vacuum thermostat or vacuum insulation tube). The basic unit of the superconducting winding is a superconducting coil. Multiple superconducting coil units are arranged in a ring in the horizontal direction to form one phase winding of the reactor. The three-phase windings are stacked vertically in the Dewar and immersed in liquid nitrogen, maintaining the temperature at the operating temperature (below 77K). The outside is at room temperature, so the outer shell generally uses a double-layer vacuum insulation Dewar. The Dewar structure includes an outer cylinder and an inner cylinder, with multiple layers of insulation material filled between the outer and inner cylinders and a vacuum evacuated. For example, invention publication number CN119252594A discloses a compact three-phase superconducting hollow reactor.

[0003] In the superconducting state, the coil has essentially zero resistance, and the current is primarily determined by the inductance. Once the superconducting layer loses its superconductivity, the resistance instantly changes from zero to very high, forcing the current to flow through the metal layers in the strip (copper encapsulation layer, stabilizing layer, etc.), increasing the overall resistance of the strip. The current is then determined by both the inductance and resistance, thus decreasing the current.

[0004] The superconducting coil units of the reactor are electrically connected in parallel. If a localized quench occurs in the strip of one coil unit, the current in the other parallel coil units will increase. Since the AC loss of the superconducting strip is closely related to the current, an increase in current leads to a significant increase in loss, which in turn increases the reactor's losses. When the total loss exceeds the cooling power output of the chiller, the internal temperature of the reactor cannot be maintained at the operating temperature, causing the entire reactor to quench due to overheating. Therefore, timely monitoring of quenching in each coil strip is crucial for the safe operation of the superconducting reactor.

[0005] When a coil fails to quench, the magnetic field around it changes, and the change is greater the closer the coil is to the quenching coil. Therefore, to determine if a coil has failed by detecting the magnetic field, the magnetic sensor needs to be as close as possible to the quenching coil to accurately locate it. This requires deploying many magnetic sensors to ensure close proximity to each coil, resulting in high cost and complex installation. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art by providing a method and apparatus for live inspection of superconducting reactors for quench detection, which uses fewer magnetic sensors for quench detection, thereby reducing costs, installation complexity, and potential hazards.

[0007] The objective of this invention can be achieved through the following technical solutions: A live-line inspection method for superconducting reactors for quench detection includes the following steps: During the operation of the superconducting reactor under test, a magnetic sensor is attached to the outer wall of the superconducting reactor to measure the magnetic field in real time. The magnetic sensor is moved along the direction of the largest increase in magnetic field gradient to locate the maximum value of the magnetic field in each region of the superconducting reactor and to make a preliminary estimate of the quench position. When the quench location is initially estimated, magnetic sensors are set at multiple locations of the superconducting reactor to measure the magnetic field. Based on the superconducting coil parameters of the superconducting reactor and the positions of the magnetic sensors, the electromagnetic coefficient matrix is ​​determined to calculate the current magnitude of the superconducting coil group corresponding to the location of the magnetic sensor, thereby achieving precise location of the quench location.

[0008] Furthermore, in the initial estimation process, if the magnetic field detected by the magnetic sensor increases, but the magnetic field detected by the magnetic sensor does not show an increasing trend when the magnetic sensor moves on the outer wall of the superconducting reactor, then it is considered that the change in magnetic field is caused by external factors and no quenching phenomenon has occurred.

[0009] Furthermore, the superconducting reactor is provided with branches of multiple superconducting coil groups.

[0010] Furthermore, during the precise location of the quench failure, the number of magnetic sensors used is no less than the number of circuits in the superconducting coil group; The equation for calculating the current magnitude of the superconducting coil assembly is as follows: In the formula, ~ The parameters within the electromagnetic coefficient matrix are determined by the parameters of the superconducting coils and the position of the magnetic sensor, where n is the number of paths in the superconducting coil group. I 1 ~I n The magnitude of the current flowing through each superconducting coil group. B 1~ B n The magnitude of the magnetic field is measured by the magnetic sensor corresponding to each superconducting coil group.

[0011] Furthermore, during the precise location of the quench failure, the number of magnetic sensors used is no less than the number of superconducting coils minus one; the method also includes acquiring the current flowing through the superconducting toroidal hollow reactor. I ; The equation for calculating the current magnitude of the superconducting coil assembly is as follows: In the formula, ~ The parameters within the electromagnetic coefficient matrix are determined by the parameters of the superconducting coils and the position of the magnetic sensor, where n is the number of paths in the superconducting coil group. I 1 ~I n The magnitude of the current flowing through each superconducting coil group. B 1~ B n-1 The magnitude of the magnetic field is measured by the magnetic sensor corresponding to the n-1 superconducting coil group.

[0012] Furthermore, the current flowing through the superconducting toroidal hollow reactor... I The measurements were obtained through the Rogowski coil at the bushing of the superconducting toroidal hollow reactor.

[0013] Furthermore, the electromagnetic coefficient matrix is ​​obtained by performing simulation calculations on the relationship between branch current and magnetic field magnitude in the superconducting reactor under test.

[0014] Furthermore, during the precise location of the quench failure, magnetic sensors are set up based on the location of the maximum magnetic field in each region of the superconducting reactor.

[0015] Furthermore, during the process of measuring the magnetic field magnitude using a magnetic sensor, the method adjusts the measurement result based on the shielding efficiency of the two metal layers inside the superconducting reactor. The expression for calculating the final magnetic field magnitude of the magnetic sensor is as follows: In the formula, Bcal is the final magnetic field magnitude of the magnetic sensor, and Bmea is the measured magnetic field value of the magnetic sensor. 1 represents the shielding efficiency of the inner cylinder of the superconducting reactor. 2 represents the shielding rate of the outer cylinder of the superconducting reactor.

[0016] Furthermore, when measuring the partial discharge signal using a magnetic sensor; or when calculating the inductance by measuring the voltage and current of the superconducting reactor in real time, and determining that the inductance change amplitude is greater than a preset inductance change threshold, a preliminary estimate of the quench position is made.

[0017] Furthermore, both the magnetic sensor and the superconducting reactor are connected to a processor via wireless communication for information exchange.

[0018] The present invention also provides a live inspection device for superconducting reactors for quench detection, comprising a memory and a processor, wherein the memory stores a computer program, and the processor calls the computer program to execute the steps of the method described above.

[0019] Compared with the prior art, the present invention has the following advantages: (1) This invention proposes to realize two-stage quench position detection of superconducting reactors by using magnetic sensors. In the first stage of preliminary estimation, magnetic sensors are attached to the outer wall of the superconducting reactor to measure the magnetic field and move towards the direction with the largest magnetic field gradient to obtain the position of the largest magnetic field, thereby initially determining whether there is a quench. After determining that there is a quench, multiple magnetic sensors are set up to measure the magnetic field simultaneously, and the current of the superconducting coil group of each branch is calculated based on the electromagnetic coefficient matrix to realize accurate estimation of the quench position. The overall scheme realizes detection with fewer magnetic sensors, which can significantly reduce costs, installation complexity and potential hazards.

[0020] (2) The present invention also considers that changes in the magnetic field caused by external factors will cause distortion of the quench detection results of this scheme. If it is determined that the magnetic field detected by the magnetic sensor increases, but the magnetic field detected by the magnetic sensor does not show an increasing trend when the magnetic sensor moves on the outer wall of the superconducting reactor, it is considered that the change in the magnetic field is caused by external factors, thus improving the accuracy of quench detection.

[0021] (3) In view of the influence of the Dewar structure of the superconducting toroidal hollow reactor on the magnetic sensor, the present invention corrects the magnetic field measurement values ​​of each part of the magnetic sensor in different regions, thereby further improving the accuracy of the quench detection of the present invention. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating a live inspection method for superconducting reactors used for quench detection, provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of a superconducting reactor provided in the background art of this invention; Figure 3 This is a three-dimensional magnetic field diagram of a toroidal inductor winding with a timeout provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of a three-dimensional horizontal cross-section of the magnetic field of a toroidal inductor winding with a timeout failure provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the magnetic field contour lines on the Dewar surface of a one-way timeout superconducting reactor provided in an embodiment of the present invention. Detailed Implementation

[0023] 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 with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0026] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed during use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] It should be noted that 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. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0028] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but can be slightly tilted.

[0029] Example 1 like Figure 1 As shown, this embodiment provides a live-line inspection method for superconducting reactors for quench detection, including the following steps: S1: During the operation of the superconducting reactor under test, a magnetic sensor is attached to the outer wall of the superconducting reactor to measure the magnetic field in real time. The magnetic sensor is moved along the direction of the largest increase in magnetic field gradient to locate the maximum value of the magnetic field in each region of the superconducting reactor and to make a preliminary estimate of the quench position. S2: When the quench location is initially estimated, magnetic sensors are set at multiple locations of the superconducting reactor to measure the magnetic field. Based on the superconducting coil parameters of the superconducting reactor and the location of the magnetic sensors, the electromagnetic coefficient matrix is ​​determined to calculate the current magnitude of the superconducting coil group corresponding to the location of the magnetic sensor, thereby achieving precise location of the quench location.

[0030] Specifically, in the preliminary estimation of the quench position in step S1, one or more high-performance magnetic sensors can be configured. By manually or with a robotic arm inspecting the outside of the reactor, the magnetic sensors are attached to the outer wall of the Dewar and moved to detect the quench coil, thus realizing a portable live detection mode.

[0031] Taking a four-channel parallel configuration as an example, if one channel experiences a quench, the current decreases rapidly, even dropping to zero. This results in a decrease in the magnetic field inside the coil and an increase in the magnetic field outside the coil. Figure 3 As shown in Figure 4.

[0032] As the magnetic sensor moves along the outer wall of the Dewar flask, it measures the magnetic field in real time. By moving along the direction of maximum magnetic field gradient, it finds the location of the strongest magnetic field, thus pinpointing the quenching coil. Figure 5 As shown.

[0033] Preferably, since there may be multiple maximum points, the surface of the Dewar can be roughly inspected first to find several areas with larger magnetic fields, and then the magnetic field maximum value of each area can be found.

[0034] Optionally, a "fixed installation + inspection and supplementation" mode can be adopted - basic magnetic sensors are fixedly arranged on the outer wall of the Dewar according to phase, with 3-4 sensors per phase to cover the entire magnetic field. At the same time, portable magnetic detection equipment is configured to accurately locate the quench position through live inspection when a suspicious signal appears.

[0035] Preferably, in the preliminary estimation process, if the magnetic field detected by the magnetic sensor increases, but the magnetic field detected by the magnetic sensor does not show an increasing trend when the magnetic sensor moves on the outer wall of the superconducting reactor, then it is considered that the change in magnetic field is caused by external factors and no quenching phenomenon has occurred.

[0036] During the precise location of the quench position in step S2, considering that the equivalent inductance of the superconducting reactor changes when the coil quenches, the inductance can be calculated by measuring the voltage and current of the reactor in real time. If the inductance changes significantly, the magnetic sensor inspection process is triggered, and the quench position is precisely located through live inspection.

[0037] That is, when the ultrasonic sensor detects a partial discharge signal, it triggers the magnetic sensor inspection process—based on the preliminary area of ​​partial discharge, it controls the magnetic sensor to move and scan on the outer wall of the corresponding reactor, and accurately locates the quench position through live inspection.

[0038] In the specific precise positioning process, multiple magnetic sensors inspected by humans or robotic arms can calculate the current magnitude of each branch, thereby monitoring the specific development process of quenching.

[0039] Taking an n-way parallel configuration as an example, the current flowing through each branch is as follows: I 1 ~I n Then the magnetic field of each sensor B 1~ B n The result can be obtained by calculation using the following formula: In the formula, ~ The parameters within the electromagnetic coefficient matrix are determined by the parameters of the superconducting coils and the position of the magnetic sensor, where n is the number of paths in the superconducting coil group. I 1 ~I n The magnitude of the current flowing through each superconducting coil group. B 1~ B n The magnitude of the magnetic field is measured by the magnetic sensor corresponding to each superconducting coil group.

[0040] Electromagnetic coefficient matrix ~ The relationship between branch current and magnetic field magnitude is obtained through prior simulation calculations of the superconducting reactor under test.

[0041] Therefore, according to B 1~ B n and s 11 ~s nn It can be calculated I 1 ~I n This allows us to determine which specific coil branch has lost overrun.

[0042] Preferably, during the precise location of the quench failure, the number of magnetic sensors used is no less than the number of superconducting coil groups minus one; the method also includes acquiring the current flowing through the superconducting toroidal hollow reactor. I That is, the sum of the currents flowing through each branch. It can be achieved by using the magnetic fields of n-1 sensors to calculate the current magnitude of n branches.

[0043] The equation for calculating the current magnitude of the superconducting coil assembly is as follows: In the formula, ~ The parameters within the electromagnetic coefficient matrix are determined by the parameters of the superconducting coils and the position of the magnetic sensor, where n is the number of paths in the superconducting coil group. I 1 ~I n The magnitude of the current flowing through each superconducting coil group. B 1~ B n-1 The magnitude of the magnetic field is measured by the magnetic sensor corresponding to the n-1 superconducting coil group.

[0044] Therefore, it can be calculated that I 1 ~I n This allows us to determine which specific coil branch has lost overrun.

[0045] Optionally, the current carrying capacity of the superconducting toroidal air-core reactor... I The measurements were obtained through the Rogowski coil at the bushing of the superconducting toroidal hollow reactor.

[0046] The principle for selecting sensor locations is to distribute them as widely as possible. In the process of accurately locating the quench point, magnetic sensors are set according to the locations of the maximum magnetic field values ​​in each region of the superconducting reactor.

[0047] Preferably, during the process of measuring the magnetic field magnitude using a magnetic sensor, the method adjusts the magnetic field magnitude measurement result based on the shielding ratio of the two metal layers inside the superconducting reactor; That is, the magnetic sensor is located outside the Dewar breaker. Considering that the Dewar structure will provide some shielding for the magnetic field, the shielding effect of the two layers of metal needs to be taken into account. Let the shielding rate be... 1. 2 (0 < 1<1, 0< 2<1), the measured value of the magnetic sensor is Bmea, and the calculation expression for the final magnetic field magnitude of the magnetic sensor used to determine quench loss is: In the formula, Bcal is the final magnetic field magnitude of the magnetic sensor, and Bmea is the measured magnetic field value of the magnetic sensor. 1 represents the shielding efficiency of the inner cylinder of the superconducting reactor. 2 represents the shielding rate of the outer cylinder of the superconducting reactor.

[0048] Preferably, when the partial discharge signal is measured by a magnetic sensor, or when the inductance is calculated by real-time measurement of the voltage and current of the superconducting reactor and the change in inductance is determined to be greater than a preset inductance change threshold, a preliminary estimate of the quench position is then made.

[0049] Optionally, both the magnetic sensor and the superconducting reactor are connected to a processor via wireless communication for information exchange, such as the exchange of voltage, current, and partial discharge information.

[0050] Optionally, the live inspection device can be adapted to the testing needs of multiple superconducting reactors. The same set of equipment can be used for multiple reactors, which is suitable for scenarios with multiple reactor clusters and can significantly reduce costs.

[0051] Example 2 This embodiment provides a live inspection device for superconducting reactors for quench detection, including a memory and a processor. The memory stores a computer program, and the processor calls the computer program to execute the steps of the live inspection method for superconducting reactors for quench detection as described in Embodiment 1.

[0052] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A live-line inspection method for superconducting reactors for quench detection, characterized in that, Includes the following steps: During the operation of the superconducting reactor under test, a magnetic sensor is attached to the outer wall of the superconducting reactor to measure the magnetic field in real time. The magnetic sensor is moved along the direction of the largest increase in magnetic field gradient to locate the maximum value of the magnetic field in each region of the superconducting reactor and to make a preliminary estimate of the quench position. When the quench location is initially estimated, magnetic sensors are set at multiple locations of the superconducting reactor to measure the magnetic field. Based on the superconducting coil parameters of the superconducting reactor and the location of the magnetic sensors, the electromagnetic coefficient matrix is ​​determined to calculate the current magnitude of the superconducting coil group corresponding to the location of the magnetic sensor, thereby achieving precise location of the quench location. The superconducting reactor has multiple branches of superconducting coil groups. During the precise location of the quench failure, the number of magnetic sensors used is no less than the number of circuits in the superconducting coil group; the equation for calculating the current magnitude of the superconducting coil group is: In the formula, ~ The parameters within the electromagnetic coefficient matrix are determined by the parameters of the superconducting coils and the position of the magnetic sensor, where n is the number of paths in the superconducting coil group. I 1 ~I n The magnitude of the current flowing through each superconducting coil group. B 1~ B n The magnitude of the magnetic field is measured by the magnetic sensor corresponding to each superconducting coil group; Alternatively, during the precise location of the quench failure, the number of magnetic sensors set is not less than the number of paths of the superconducting coil group minus 1; the method further includes obtaining the current flowing through the superconducting toroidal hollow reactor. I The equation for calculating the current magnitude of the superconducting coil assembly is as follows: In the formula, ~ The parameters within the electromagnetic coefficient matrix are determined by the parameters of the superconducting coils and the position of the magnetic sensor, where n is the number of paths in the superconducting coil group. I 1 ~I n The magnitude of the current flowing through each superconducting coil group. B 1~ B n-1 The magnitude of the magnetic field measured by the magnetic sensor corresponding to the n-1 superconducting coil group; The superconducting toroidal hollow reactor has a current carrying capacity of 100%. I The measurement is obtained through the Rogowski coil or current transformer at the bushing of the superconducting toroidal hollow reactor.

2. The method for live-line inspection of a superconducting reactor for quench detection according to claim 1, characterized in that, In the initial estimation process, if the magnetic field detected by the magnetic sensor increases, but the magnetic field detected by the magnetic sensor does not show an increasing trend when the magnetic sensor moves on the outer wall of the superconducting reactor, then it is considered that the change in magnetic field is caused by external factors and no quenching phenomenon has occurred.

3. The live-line inspection method for superconducting reactors for quench detection according to claim 1, characterized in that, The electromagnetic coefficient matrix is ​​obtained by performing a simulation calculation on the relationship between the branch current and the magnetic field magnitude of the superconducting reactor under test. In the process of accurately locating the quench point, magnetic sensors are set up according to the location of the maximum magnetic field in each region of the superconducting reactor.

4. The live-line inspection method for superconducting reactors for quench detection according to claim 1, characterized in that, The method adjusts the magnetic field measurement results based on the shielding ratio of the two metal layers inside the superconducting reactor during the magnetic field magnitude measurement process using a magnetic sensor. The expression for calculating the final magnetic field magnitude of the magnetic sensor is as follows: In the formula, Bcal is the final magnetic field magnitude of the magnetic sensor, and Bmea is the measured magnetic field value of the magnetic sensor. 1 represents the shielding efficiency of the inner cylinder of the superconducting reactor. 2 represents the shielding rate of the outer cylinder of the superconducting reactor.

5. A live-line inspection method for superconducting reactors for quench detection according to claim 1, characterized in that, When measuring the partial discharge signal using a magnetic sensor; or when calculating the inductance by measuring the voltage and current of a superconducting reactor in real time, and determining that the inductance change is greater than a preset inductance change threshold, a preliminary estimate of the quench position is made.

6. A live-line inspection method for superconducting reactors for quench detection according to claim 1, characterized in that, Both the magnetic sensor and the superconducting reactor are connected to the processor via wireless communication for information exchange.

7. A live-line inspection device for superconducting reactors for quench detection, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program, and the processor invokes the computer program to perform the steps of the method as described in any one of claims 1 to 6.

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