Error field measurement method and apparatus

Abstract

An error field measurement method and apparatus. The error field measurement method comprises: acquiring an electromotive force of a poloidal field coil that is collected by a sensor (102); acquiring test data of a calibration test performed on an error field measurement system, and on the basis of the electromotive force and the test data, determining a calibration test result (104); when the calibration test result indicates that the test has passed, acquiring a voltage sensor signal of the poloidal field coil, and on the basis of the voltage sensor signal and the electromotive force, determining a poloidal magnetic flux of the poloidal field coil (106); and on the basis of the poloidal magnetic flux, determining an error field measurement result of a toroidal field coil (108). A poloidal field coil is used to measure an error field, and there is no need to introduce extra hardware components, thereby reducing the hardware cost and the measurement complexity. Meanwhile, since the poloidal field coil is precisely manufactured and accurately positioned, it is ensured that the cross-section of the poloidal field coil can be precisely oriented in a poloidal direction, thereby achieving accurate and reliable data during a measurement process, and thus improving the accuracy of error field measurement.

Description

Error field measurement method and device

[0001] This application claims priority to Chinese Patent Application No. 202411914222.4, filed on December 24, 2024, entitled "Method and Apparatus for Measuring Error Field", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of nuclear fusion technology, and in particular to error field measurement methods and apparatus. Background Technology

[0003] The toroidal field coils of a tokamak device can generate a toroidal magnetic field. However, due to factors such as positional errors in the toroidal field coils, the generated magnetic field is not entirely circumferential and also includes a poloidal component, which is called the error field. Since the absolute value of the magnetic field generated by the toroidal field coils is much larger than that generated by the poloidal field coils, this error field may have a considerable impact on the original poloidal magnetic field configuration, thus requiring evaluation of the error field.

[0004] Currently, magnetic flux loops are commonly used to measure poloidal magnetic flux. However, this method is not suitable for measuring error fields because the poloidal component of the magnetic field of the loop coil is very small (about 1 / 1000 times) relative to its dominant circumferential component. Therefore, even a slight positional error in the flux loop (ideally, the flux loop only has a poloidal cross-sectional area, but due to the positional error, there will be a net circumferential cross-sectional area) will result in the measurement of the circumferential magnetic flux, thus masking the desired error field poloidal flux. Summary of the Invention

[0005] In view of this, embodiments of this application provide an error field measurement method. One or more embodiments of this application also relate to an error field measurement device to address the technical deficiencies existing in the prior art.

[0006] According to a first aspect of the embodiments of this application, an error field measurement method is provided, comprising:

[0007] Acquire the electromotive force of the poloidal field coil collected by the sensor;

[0008] Acquire test data for calibration testing of the error field measurement system, and determine the calibration test results based on the electromotive force and test data;

[0009] If the calibration test result indicates that the test has passed, the voltage sensor signal of the poloidal field coil is acquired, and the poloidal magnetic flux of the poloidal field coil is determined based on the voltage sensor signal and the electromotive force. The voltage sensor signal is obtained by discharging the circumferential field coil.

[0010] The error field measurement results of the circumferential field coil are determined based on the pole magnetic flux.

[0011] According to a second aspect of the embodiments of this application, an error field measuring device is provided, comprising:

[0012] The first acquisition module is configured to acquire the electromotive force of the poloidal field coil collected by the sensor;

[0013] The first determining module is configured to acquire test data for calibration testing of the error field measurement system, and determine the calibration test results based on the electromotive force and the test data.

[0014] The second determining module is configured to acquire the voltage sensor signal of the poloidal field coil when the calibration test result indicates that the test has passed, and determine the poloidal magnetic flux of the poloidal field coil based on the voltage sensor signal and the electromotive force, wherein the voltage sensor signal is obtained based on the discharge operation of the circumferential field coil;

[0015] The third determining module is configured to determine the error field measurement results of the circumferential field coil based on the pole magnetic flux.

[0016] An embodiment of this application provides an error field measurement method, comprising: acquiring the electromotive force (EMF) of a poloidal field coil collected by a sensor; acquiring test data for calibration testing of the error field measurement system, and determining the calibration test result based on the EMF and the test data; if the calibration test result indicates that the test has passed, acquiring the voltage sensor signal of the poloidal field coil, and determining the poloidal magnetic flux of the poloidal field coil based on the voltage sensor signal and the EMF, wherein the voltage sensor signal is obtained based on a discharge operation on the circumferential field coil; and determining the error field measurement result of the circumferential field coil based on the poloidal magnetic flux. Measuring the error field of the circumferential field coil using the poloidal field coil in a tokamak device eliminates the need for additional hardware components, reducing hardware costs and measurement complexity. Furthermore, because the poloidal field coil is precisely manufactured and accurately positioned, its cross-section is precisely along the poloidal direction, ensuring accurate and reliable data during the measurement process and improving the accuracy of the poloidal magnetic flux and error field measurement results. Attached Figure Description

[0017] Figure 1 is a flowchart of an error field measurement method provided in an embodiment of this application;

[0018] Figure 2 is a schematic diagram of a tokamak device provided in one embodiment of this application;

[0019] Figure 3 is a schematic diagram of the connection between a sensor and a poloidal field coil according to an embodiment of this application;

[0020] Figure 4 is a schematic diagram of the connection between another sensor and a poloidal field coil provided in one embodiment of this application;

[0021] Figure 5 is a schematic diagram of a circuit model provided in an embodiment of this application;

[0022] Figure 6 is a schematic diagram of the measurement results of poloidal magnetic flux provided in an embodiment of this application;

[0023] Figure 7 is a schematic diagram of the deformation of another circumferential field coil provided in one embodiment of this application;

[0024] Figure 8 is a schematic diagram of the deformation of a circumferential field coil according to an embodiment of this application;

[0025] Figure 9 is a schematic diagram of an error field measurement device provided in one embodiment of this application. Detailed Implementation

[0026] Many specific details are set forth in the following description to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below.

[0027] The terminology used in one or more embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of one or more embodiments of this application. The singular forms “a,” “the,” and “the” used in one or more embodiments of this application and in the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” used in one or more embodiments of this application refers to and includes any or all possible combinations of one or more associated listed items.

[0028] It should be understood that although the terms first, second, etc., may be used to describe various information in one or more embodiments of this application, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first may also be referred to as second without departing from the scope of one or more embodiments of this application, and similarly, second may also be referred to as first. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination."

[0029] Furthermore, it should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in one or more embodiments of this application are all information and data authorized by the user or fully authorized by all parties. Moreover, the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and corresponding operation entry points are provided for users to choose to authorize or refuse.

[0030] First, the terms and concepts involved in one or more embodiments of this application will be explained.

[0031] Tokamak: A device that uses a strong magnetic field to confine high-temperature plasma within a toroidal space, designed to simulate the nuclear fusion reaction conditions inside the sun in order to achieve controlled nuclear fusion.

[0032] A toroidal field (TF) coil is a coil that surrounds a tokamak device. The toroidal field coil generates a toroidal magnetic field that confines the plasma within a toroidal path. The cross-section of the toroidal field coil is circumferential and responds to the toroidal magnetic flux.

[0033] A poloidal field (PF) coil is a coil located outside the vacuum chamber of a tokamak and can be called a vertical field coil. The poloidal field coil generates a poloidal magnetic field, which can control the shape, position, and vertical stability of the plasma. The cross-section of the poloidal field coil is along the poloidal direction and responds to the poloidal magnetic flux.

[0034] A flux loop is a coil without a power source that is coaxial and parallel to the poloidal field coil. The cross section of the flux loop is along the poloidal direction, and it generates an electromotive force in response to changes in the poloidal magnetic flux.

[0035] Error Fields: Theoretically, a circumferential field coil generates a circumferential magnetic field. However, due to factors such as shape errors in the circumferential field coil, a poloidal magnetic field component is generated. This poloidal magnetic field component is called the error field of the circumferential field coil.

[0036] In traditional methods, the poloidal magnetic flux generated by the toroidal field coils of a tokamak device can be measured using a flux loop. The physical principle of the measurement process is electromagnetic induction: the electromotive force (EMF) in a loop is equal to the rate of change of the magnetic flux enclosed by that loop. By measuring the EMF and integrating over time, the magnetic flux value at the corresponding time can be obtained. However, this method is not suitable for measuring error fields because the poloidal component of the magnetic field of the toroidal field coil is extremely small (approximately 1 / 1000 times) compared to its dominant toroidal component. Therefore, even a slight positional error in the flux loop (ideally, the flux loop only has a poloidal cross-sectional area, but due to its positional error, it will have a net toroidal cross-sectional area) will result in the measurement of the toroidal magnetic flux, thus masking the desired error field poloidal flux. In other words, when measuring the error field, the signal in the above method mainly depends on the shape error of the flux loop, rather than the shape error of the toroidal field coil. In practical applications, the deformation of the toroidal field coil can also be directly measured, and then the error field can be calculated in the forward direction. However, this method is expensive and cumbersome. For objects such as toroidal field coils that are large in size but have small deformation, it requires the use of very expensive laser tracker equipment and special environmental setup, resulting in extremely high measurement costs and complexity.

[0037] To address the aforementioned issues, this application proposes a scheme for measuring the error field using a poloidal field coil. When measuring the magnetic flux of the toroidal field coil's error field, it is crucial to ensure the accurate positioning of the flux loop, with its cross-section precisely aligned with the poloidal direction. The poloidal field coil of a tokamak device is precisely manufactured and accurately installed (e.g., the installation process can be verified using a laser tracker, with an error less than 0.1 mm). Therefore, the poloidal field coil can function as a "double" flux loop to measure the error field. Specifically, the electromotive force (EMF) of the poloidal field coil is acquired by a sensor; test data for calibration of the error field measurement system is acquired, and the calibration test result is determined based on the EMF and test data; if the calibration test result indicates a pass, the voltage sensor signal of the poloidal field coil is acquired, and the poloidal magnetic flux of the poloidal field coil is determined based on the voltage sensor signal and the EMF, wherein the voltage sensor signal is obtained by discharging the toroidal field coil; and the error field measurement result of the toroidal field coil is determined based on the poloidal magnetic flux.

[0038] It is worth noting that because the poloidal field coil is accurately positioned, the data obtained during the measurement process are reliable. Furthermore, the poloidal field coil is multi-turn, providing a high signal-to-noise ratio. Simultaneously, since the poloidal field coil is a readily available component in the tokamak device, no additional measurement equipment is required, reducing hardware costs and measurement complexity. The measurement scheme proposed in this application can relatively accurately evaluate the error field of the circumferential field coil and is applicable to any tokamak device.

[0039] This application provides an error field measurement method and also relates to an error field measurement device, which will be described in detail in the following embodiments.

[0040] Referring to Figure 1, Figure 1 shows a flowchart of an error field measurement method provided in an embodiment of this application, which specifically includes the following steps:

[0041] Step 102: Obtain the electromotive force of the poloidal field coil collected by the sensor.

[0042] It should be noted that during error field measurement, the magnitude of the error field, measured in poloidal magnetic flux, as well as the positional error and shape deformation of the circumferential field coils that cause the error field, can be measured. A sensor is a device capable of detecting or responding to specific physical, chemical, or biological phenomena and converting this information into measurable signals (usually electrical signals). Referring to Figure 2, Figure 2 shows a schematic diagram of a tokamak device according to an embodiment of this application. The tokamak device includes a toroidal vacuum chamber, a poloidal field coil, a circumferential field coil, and an ohmic field coil. The circumferential field coil surrounds the tokamak device. The poloidal field coils are distributed outside the toroidal vacuum chamber. The toroidal vacuum chamber is the site for plasma current generation and maintenance, and by providing a high vacuum environment and supporting a complex magnetic confinement system, efficient generation and stable control of the plasma current can be ensured.

[0043] In practical applications, there are various ways to obtain the electromotive force (EMF) of the poloidal field coil acquired by the sensor, and the specific method is selected according to the actual situation. This application does not limit this method in any way. In one possible implementation of this application, the voltage value acquired by the sensor can be read directly, and the EMF of the poloidal field coil can be determined based on the voltage value. In another possible implementation of this application, when the poloidal field coil is of the series type, and multiple signal lines are connected in series with a ground wire, only one signal line can be directly twisted with the ground wire, while the remaining signal lines will form a large toroidal area. This additional toroidal area will respond to the toroidal magnetic flux of the toroidal field coil, causing interference to the measurement. Therefore, the EMF of the poloidal field coil acquired by the sensor can be obtained according to the coil type of the poloidal field coil.

[0044] In one embodiment of this application, the acquisition of the electromotive force of the poloidal field coil collected by the sensor may include the following steps:

[0045] Obtain the coil type of the poloidal field coil;

[0046] Based on the coil type, the electromotive force of the poloidal field coil acquired by the sensor is obtained.

[0047] It should be noted that the coil type is a classification of poloidal field coils based on their connection relationships. Coil types include non-series and series types. Non-series poloidal field coils are those with independent power supplies; each coil has its own independent power source, and there is no direct electrical connection between them. Non-series poloidal field coils have characteristics including, but are not limited to, the following: Independent current: Each poloidal field coil can independently control the magnitude and direction of its current, facilitating individual adjustment and optimization. Flexible control: The operating parameters of each poloidal field coil can be precisely adjusted as needed to achieve complex magnetic field configurations. Series poloidal field coils are those connected in series, forming a continuous circuit where all coils share the same power source. Characteristics include, but are not limited to, the following: Consistent current: The current in all poloidal field coils is equal, as the current is the same throughout a series circuit. Voltage distribution: The sum of the voltages across the poloidal field coils equals the power supply voltage. Simple structure: Only one power source is needed to drive all poloidal field coils, simplifying power supply configuration and control systems.

[0048] In practical applications, when obtaining the electromotive force (EMF) of the poloidal field coil acquired by the sensor, depending on the coil type, if the coil type is not series-connected, the EMF of the poloidal field coil acquired by the second sensor is obtained. This second sensor is a power sensor. If the coil type is series-connected, it indicates that there is a series relationship between the poloidal field coils. To obtain the EMF of a single poloidal field coil, an additional voltage sensor (first sensor) must be added. When adding the additional first sensor, first locate the grounding point of the series-connected poloidal field coils and use it as the common point for all voltage sensors. Then, connect it sequentially to the ribbon cable of each poloidal field coil, ensuring that each signal line can be twisted to the ground wire, and keeping the first sensor away from the poloidal field coil.

[0049] By applying the solution of this application embodiment, the electromotive force of the poloidal field coil collected by the sensor is obtained according to the coil type, thereby realizing the acquisition of electromotive force according to specific circumstances, ensuring the accuracy of electromotive force, and making the solution proposed in this application embodiment applicable to any tokamak device.

[0050] In one embodiment of this application, obtaining the electromotive force of the poloidal field coil collected by the sensor according to the coil type may include the following steps:

[0051] When the coil type is series type, the electromotive force of the poloidal field coil collected by the first sensor is obtained. The first sensor and the poloidal field coil share a common ground. A target resistor is connected in series on the ground wire of the poloidal field coil. The two ends of the target resistor are connected to the target ground wire. The target ground wire is twisted with a voltage signal line that is not twisted with the ground wire. The target resistance is greater than the resistance of the wire.

[0052] Referring to Figure 3, which shows a schematic diagram of the connection between a sensor and a poloidal field coil according to an embodiment of this application, there is an 80Ω resistor on the ground wire, and the signal line, ground wire, and sensor are connected. For two poloidal field coils that are connected in series, since the number of signal lines (two) and ground wire (one) is not equal, only one signal line and ground wire can be directly twisted together, and the other signal line will form an additional toroidal area.

[0053] Referring to Figure 4, which shows a schematic diagram of the connection between another sensor and a poloidal field coil according to an embodiment of this application, there is an 80Ω resistor on the ground wire, and the signal line, ground wire, and sensor are connected. To eliminate the additional toroidal area, a target resistor can be connected in series on the ground wire. The target resistor can be 10-100Ω. A target ground wire is led out from both ends of the target resistor, so that the target ground wire wraps around the additional toroidal area (closely following the poloidal field coil wiring and twisted with the signal line), thereby canceling out the additional toroidal area.

[0054] By applying the scheme of this application embodiment, the target ground wire is twisted with a voltage signal line that is not twisted with the ground wire, creating a new, controlled small loop. The magnetic field generated by this loop can interact with the magnetic field generated by the original larger loop, effectively canceling the magnetic field in the original loop, reducing the induced electromotive force and the noise caused therefrom, and ensuring the accuracy of the electromotive force.

[0055] Next, an experiment was conducted to select the target resistor value. Referring to Figure 5, Figure 5 shows a schematic diagram of a circuit model provided in one embodiment of this application. The large-loop electromotive force U1 represents the electromotive force including the additional toroidal area, and the small-loop electromotive force U2 represents the electromotive force excluding the additional toroidal area. R1 represents the target resistor, R2 represents the wire resistance, and R0 represents the voltmeter resistance. The experimental objective was to select R1 and R2 such that the voltage across the voltmeter is close to U2. The circuit equation for this system is shown in the following formula (1), where I0 represents the voltmeter current:

[0056] Assuming the resistance R0 of the voltmeter is much greater than R1 and R2, then the following formula (2) is obtained:

[0057] It is evident that the condition for I0R0 to be approximately equal to U2 requires the simultaneous satisfaction of the following formulas (3) and (4):

[0058] In practical applications, the electromotive force generated by the toroidal area is usually not much larger than the stray electromotive force of the poloidal coil. Therefore, U1 is approximately several times U2. On the other hand, since R2 is the resistance of the wire and its resistance is very small, R1 only needs to be several times larger than the resistance of the wire. However, considering contact resistance, etc., preferably, R1 is much larger than R2, but much smaller than R0, such as 10-100Ω.

[0059] Step 104: Obtain test data for calibration testing of the error field measurement system, and determine the calibration test results based on the electromotive force and test data.

[0060] It should be noted that the error field measurement system includes measurement components such as sensors, ammeters, voltmeters, and amplifiers. Calibration testing refers to the process of adjusting or verifying the accuracy of measuring instruments, equipment, or systems using a series of known standards to ensure that their output truly reflects the measured physical quantity. Calibration testing not only ensures the accuracy of measurement results but also identifies and corrects deviations or errors in the system, thereby improving the reliability and consistency of measurement data. Test data is the data used in the calibration testing process. Test data includes at least one of the following: the test current of the active coil and the test current change index of the active coil. The test current change index refers to the change in current per unit time, reflecting the rate of change of current over time.

[0061] In practical applications, there are various ways to obtain test data for calibration testing of the error field measurement system, and the specific method chosen depends on the actual situation. This application does not impose any limitations on this method. In one possible implementation, test data for calibration testing of the error field measurement system sent by a user can be received. In another possible implementation, test data for calibration testing of the error field measurement system can be read from other data acquisition devices or databases.

[0062] Furthermore, there are various ways to determine the calibration test results based on the electromotive force and test data, and the specific method should be selected according to the actual situation. This application does not limit this method in any way. In one possible implementation of this application, the poloidal field coil includes an active coil and a passive coil, the electromotive force is the electromotive force of the passive coil, and the test data includes the test current change index of the active coil. The magnetic flux change index can be determined based on the test current change index; the calibration test results are determined according to the electromotive force and the magnetic flux change index.

[0063] In another possible implementation of this application, the poloidal field coil includes an active coil and a passive coil, the electromotive force is the electromotive force of the passive coil, and the test data includes the test current of the active coil; the determination of the calibration test result based on the electromotive force and the test data may include the following steps:

[0064] Based on the test current, determine the magnetic flux change index;

[0065] The calibration test results are determined based on the electromotive force and magnetic flux change indicators.

[0066] It should be noted that the magnetic flux change index describes the change in magnetic flux through a closed loop or area per unit time. The magnetic flux change index reflects the rate of change of the magnetic field over time. Calibration test results include pass and fail. If the calibration test is passed, it indicates that the current error field measurement system is accurate and can output the true measured physical quantity. If the calibration test fails, it indicates that the current error field measurement system is inaccurate and cannot output the true measured physical quantity. In this case, the error field measurement system can be adjusted, and the adjusted error field measurement system can be recalibrated until the calibration test result indicates a pass. An active coil is a coil powered by an external power source and controlled to generate a specific magnetic field. The main function of an active coil is to generate and adjust the magnetic field to achieve precise control over the shape, position, and other parameters of the plasma. Active coils include, but are not limited to, the following characteristics: Controllable current: The current can be precisely adjusted by the control system to generate the required magnetic field strength and direction. Dynamic adjustment: The current can be changed in real time according to experimental needs, thereby dynamically adjusting the magnetic field. High-precision power supply: Each active coil is usually equipped with an independent high-precision power supply to ensure the stability and adjustability of the current. A passive coil is a coil that is not directly powered by an external power source, but rather relies on the induced current generated by changes in plasma or other magnetic fields to operate. It is primarily used to provide additional magnetic field support, especially to enhance magnetic field stability under certain specific conditions. Passive coils have, but are not limited to, the following characteristics: No external power source: They do not require an external power supply and rely on electromagnetic induction to generate current. Adaptive characteristics: They automatically respond to changes in the surrounding environment, providing additional magnetic field support.

[0067] In practical applications, when calibrating an error field measurement system based on electromotive force (EMF) and test data, a known test current can be applied to a pair of active coils. Based on this test current, the current change index can be determined, and further, the magnetic flux change index in space can be determined. The calibration test result is then determined based on the EMF and magnetic flux change index. Specifically, the relationship between the EMF and magnetic flux change index should satisfy the condition that the magnetic flux change index on the passive coil equals the EMF. Therefore, if the EMF does not equal the magnetic flux change index, the calibration test result is determined to be a failure; if the EMF equals the magnetic flux change index, the calibration test result is determined to be a success.

[0068] By applying the scheme of this application embodiment, the calibration test results are determined based on the electromotive force and magnetic flux change indicators, thereby accurately calibrating the error field measurement system and ensuring that subsequent error field measurements can be performed only after the error field measurement system has passed the test.

[0069] Step 106: If the calibration test result indicates that the test has passed, acquire the voltage sensor signal of the poloidal field coil, and determine the poloidal magnetic flux of the poloidal field coil based on the voltage sensor signal and the electromotive force. The voltage sensor signal is obtained by discharging the circumferential field coil.

[0070] It should be noted that the voltage sensor signal is obtained based on the discharge operation of the toroidal field coil. In one embodiment of this application, to ensure that the discharge operation can cover different operating conditions and provide sufficient information for subsequent data analysis, a series of discharge experiments of different intensities can be performed on the toroidal field coil. For example, the current magnitude of the toroidal field coil can be divided into at least three groups (e.g., low, medium, and high levels), and the voltage sensor signal on the corresponding poloidal field coil can be recorded. The voltage sensor signal of the poloidal field coil can reflect the change in electromotive force induced by the poloidal field coil. The poloidal magnetic flux of the poloidal field coil refers to the magnetic flux through a specific area of ​​the magnetic field generated by the poloidal field coil, which can be called the error poloidal magnetic flux.

[0071] In practical applications, there are various ways to determine the poloidal flux of the poloidal field coil based on the voltage sensor signal and electromotive force. The specific method is selected according to the actual situation, and this application does not limit this method. In one possible implementation of this application, the zero-point drift of the voltage sensor signal can be directly eliminated to obtain the target signal; the poloidal flux of the poloidal field coil is then determined based on the target signal.

[0072] In another possible implementation of this application, since the signal gain coefficient of the poloidal field coil may not be 1, the signal gain coefficient of the poloidal field coil can be incorporated into the process of determining the poloidal magnetic flux. That is, the above-mentioned determination of the poloidal magnetic flux of the poloidal field coil based on the voltage sensor signal and electromotive force may include the following steps:

[0073] Based on the electromotive force, determine the signal gain coefficient of the poloidal field coil;

[0074] Eliminate zero-point drift of the voltage sensor signal to obtain the target signal;

[0075] The poloidal flux of the poloidal field coil is determined based on the target signal and the signal gain coefficient.

[0076] It should be noted that the signal gain coefficient refers to the proportional relationship between the sensor's output voltage and the electromotive force (EMF) of the poloidal field coil. Signal gain coefficient = EMF / flux change index. Zero drift refers to the phenomenon where, even without an input signal or when the output should ideally be zero, the sensor or measurement system still has a non-zero output value, and this value changes slowly with time, temperature, or other environmental conditions. Zero drift affects the accuracy of measurement results.

[0077] In practical applications, when eliminating the zero-point drift of the voltage sensor signal, the full-time average value of each voltage sensor signal can be subtracted, as shown in the following formula (5). By eliminating the zero-point drift of the voltage sensor signal, it can be ensured that the integrated result only reflects the real magnetic flux change and does not include any static bias.

[0078] Where V'(t) represents the target signal, V(t) represents the voltage sensor signal, and T represents the entire measurement time period.

[0079] Furthermore, when determining the poloidal flux of the poloidal field coil based on the target signal and signal gain coefficient, the target signal can first be integrated, and then the result of the integration and the signal gain coefficient can be used to determine the magnetic flux measured on each poloidal field coil. Finally, the magnetic flux on each poloidal field coil is obtained by dividing the magnetic flux by the number of turns of each coil. Here, the magnetic flux is the product of the total magnetic flux through a closed loop or coil and the number of turns of that loop. The magnetic flux is used to reflect the degree of coupling between the magnetic field and the coil. The calculation process of the magnetic flux is shown in the following formula (6), and the calculation process of the poloidal flux is shown in the following formula (7):

[0080] Where ψ represents the magnetic flux linkage, V'(t) represents the target signal, and G represents the signal gain coefficient. This represents the poloidal magnetic flux, and N represents the number of turns in each poloidal field coil.

[0081] The solution proposed in this application eliminates zero-point drift of the voltage sensor signal during the determination of the pole flux, thereby improving the accuracy of the pole flux.

[0082] In one embodiment of this application, before determining the error field measurement result of the circumferential field coil based on the pole magnetic flux, the following steps may be included:

[0083] Obtain the circumferential current of the circumferential field coil collected by the ammeter;

[0084] Based on the pole magnetic flux, determine the error field measurement results of the circumferential field coil, including:

[0085] When the pole flux is determined to be the error field flux based on the circumferential current, the error field measurement result of the circumferential field coil is determined according to the pole flux.

[0086] It should be noted that after determining the pole magnetic flux, it is possible to check whether the amplitude of the magnetic flux signal is proportional to the magnitude of the toroidal current of the toroidal field coil. If so, it indicates that the measured pole magnetic flux is indeed the flux of the error field, and further analysis can be performed to determine the measurement result of the error field of the toroidal field coil based on the pole magnetic flux. If not, it indicates that the measured pole magnetic flux is not the flux of the error field.

[0087] In practical applications, when checking whether the amplitude of the magnetic flux signal is proportional to the magnitude of the toroidal current of the toroidal field coil, a graph can be plotted showing the magnetic flux corresponding to different toroidal field coil current levels to observe whether a linear relationship exists. If a linear relationship exists, it indicates that the pole magnetic flux is the flux of the error field; if no linear relationship exists, it indicates that the measured pole magnetic flux is not the flux of the error field, and the reasons why the pole magnetic flux is not the flux of the error field can be analyzed. The reasons why the pole magnetic flux is not the flux of the error field can be analyzed from the following aspects: Hardware connection problems: Check whether all electrical connections are correct, including but not limited to sensor wiring and grounding. Sensor failure: Confirm that the voltage sensor used is not damaged or its performance has degraded. Interference sources: Investigate whether external electromagnetic interference has affected the measurement results. Data analysis errors: Review the data processing steps to ensure that all calculations are performed as expected.

[0088] The solution proposed in this application determines whether the pole flux is an error field flux by using the circumferential current, thereby ensuring the accuracy of the pole flux and laying the foundation for determining the subsequent error field measurement results.

[0089] Step 108: Determine the error field measurement results of the circumferential field coil based on the pole magnetic flux.

[0090] In practical applications, there are various methods to determine the error field measurement results of the circumferential field coil based on the pole flux. The specific method is selected according to the actual situation, and this application does not limit this approach. In one possible implementation of this application, after obtaining the pole flux of each pole field coil, the pole flux can be directly determined as the error field measurement result of the coil. In another possible implementation of this application, the cause of the error field can be determined based on the magnitude of the pole flux, that is, what positional error or deformation of the circumferential field coil caused the error field, and the cause of the error field can be determined as the error field measurement result.

[0091] The solution proposed in this application utilizes the poloidal field coil in a tokamak device to measure the error field of the circumferential field coil, eliminating the need for additional hardware components and reducing hardware costs and measurement complexity. Furthermore, the precise fabrication and accurate positioning of the poloidal field coil ensures its cross-section is precisely aligned with the poloidal direction, resulting in accurate and reliable measurement data and improving the accuracy of both the poloidal flux and error field measurement results.

[0092] In one embodiment of this application, determining the error field measurement result of the circumferential field coil based on the pole magnetic flux may include the following steps:

[0093] Using the poloidal flux, the equivalent circumferential current of the circumferential field coil is determined, wherein the simulated poloidal flux obtained by simulating the equivalent circumferential current is matched with the poloidal flux.

[0094] The error field measurement results of the circumferential field coil are determined based on the equivalent circumferential current.

[0095] In practical applications, there is a simple correlation between toroidal current and poloidal flux: a positive current is surrounded by a positive poloidal flux, which increases closer to the source. Therefore, it can be determined that there should be a positive equivalent toroidal current near the poloidal field coil where a positive magnetic flux is measured, and vice versa. Based on this, the equivalent toroidal current can be deduced from the poloidal flux: try placing positive and negative currents in the toroidal field coil outline and adjust repeatedly until the simulated poloidal flux obtained by trying to place positive and negative currents in the toroidal field coil outline matches (basically matches) the poloidal flux, thus obtaining the equivalent toroidal current of the toroidal field coil.

[0096] By applying the solution of this application embodiment, the error field measurement results of the circumferential field coil can be determined based on the equivalent circumferential current, which can accurately determine the cause of the error field and improve the comprehensiveness of the error field measurement.

[0097] Referring to Figure 6, which illustrates a schematic diagram of a poloidal flux measurement result according to an embodiment of this application, the horizontal axis of Figure 6 represents the large radius coordinate (R / m), with coordinate values ​​including 0.2, 0.6, 1, and 1.2. R represents the radial distance (i.e., the large radius) from the geometric center of the tokamak device to a point, and m represents the length unit "meter". The vertical axis represents the height coordinate (Z / m), with coordinate values ​​including -0.15, -1, -0.5, 0, 0.5, 1, and 1.5. Z represents the height or position along the axial direction of the tokamak device, typically used to describe the position of a point in the circumferential field coil in the vertical direction, and m represents the length unit "meter". The black squares in Figure 6 represent multiple poloidal field coils, and each black square corresponds to a value representing the magnitude of the simulated poloidal flux, such as -0.35.

[0098] Referring to Figure 7, which illustrates a schematic diagram of another poloidal flux measurement result provided in an embodiment of this application, the horizontal axis of Figure 7 represents the large radius coordinate (R / m), with coordinate values ​​including 0.2, 0.6, 1, and 1.2. R represents the radial distance (i.e., the large radius) from the geometric center of the tokamak device to a point, and m represents the length unit "meter". The vertical axis represents the height coordinate (Z / m), with coordinate values ​​including -0.15, -1, -0.5, 0, 0.5, 1, and 1.5. Z represents the height or position along the axial direction of the tokamak device, typically used to describe the position of a point in the toroidal field coil in the vertical direction, and m represents the length unit "meter". The black squares in Figure 7 represent multiple poloidal field coils, each corresponding to a value representing the magnitude of the simulated poloidal flux. After placing an equivalent toroidal current in the toroidal field coil, a positive and negative current pair (-50KA and 50KA) appears at the loop of the toroidal field coil, indicating that the toroidal field coil has not tilted.

[0099] In one embodiment of this application, the error field measurement result includes the cause of the error field; the above-mentioned determination of the error field measurement result of the loop field coil based on the equivalent loop current may include the following steps:

[0100] Obtain the attribute information of the circumferential field coil;

[0101] The torsion angle of the circumferential field coil is determined based on the equivalent circumferential current and property information.

[0102] If the torsion angle does not meet the standard for the circumferential field coil, the cause is determined to be deformation of the circumferential field coil.

[0103] It should be noted that the attribute information of the toroidal field coil refers to information related to the toroidal field coil itself. The attribute information of the toroidal field coil includes the toroidal circumference, number of turns, coil radius, and single-turn current. The toroidal circumference refers to the total length of the closed path formed by the toroidal field coil around the plasma. The number of turns refers to the number of turns of the wire wound in the toroidal field coil. The coil radius refers to the distance from the center of the toroidal field coil to the center of the wire. The single-turn current refers to the current intensity flowing through each turn of the wire in the toroidal field coil. Toroidal field coil standards refer to a series of specifications used to ensure that the toroidal field coil meets specific performance and safety requirements during design, manufacturing, and operation. For example, a toroidal field coil standard is that the torsion angle is zero. If the torsion angle is not zero, it is determined that the torsion angle does not meet the toroidal field coil standard, indicating that the toroidal field coil has deformed. If the torsion angle is zero, it indicates that the toroidal field coil has not deformed.

[0104] In practical applications, when determining the torsion angle of the circumferential field coil based on the equivalent circumferential current and attribute information, the torsion angle is obtained based on the circumferential deformation and the coil radius. The circumferential deformation is obtained based on the equivalent circumferential current, circumferential circumference, number of coil turns, and single-turn current. The circumferential deformation is the single-turn deformation of the circumferential field coil. The relationship between the equivalent circumferential current and the circumferential deformation is shown in the following formula (8), and the relationship between the torsion angle, the circumferential deformation, and the coil radius is shown in the following formula (9): θ×r=δ (9)

[0105] Where I1 represents the single-turn current, n represents the number of turns of the circumferential field coil, δ represents the circumferential deformation, C represents the circumferential circumference, I2 represents the equivalent circumferential current, θ represents the torsion angle, and r represents the coil radius of the circumferential field coil.

[0106] Referring to Figure 8, which shows a schematic diagram of the deformation of a circumferential field coil according to an embodiment of this application, the solid line in Figure 8 represents the deformation of the circumferential field coil, the dashed line represents the theoretical position of the circumferential field coil without deformation, and the distance between the dashed line and the solid line represents the circumferential deformation.

[0107] By applying the solution of this application embodiment, the cause of the error field can be accurately determined by using the torsion angle to determine whether the circumferential field coil has deformed.

[0108] In one embodiment of this application, the error field measurement result includes the cause of the error field; the above-mentioned determination of the error field measurement result of the loop field coil based on the equivalent loop current may include the following steps:

[0109] When the equivalent circumferential current is in the same direction, the cause is determined to be the tilting of the circumferential field coil.

[0110] It should be noted that if the equivalent circumferential current is a positive and negative current pair, it can be determined that the circumferential field coil has not tilted; if the equivalent circumferential current is in the same direction, such as both being positive or both being negative, it can be determined that the circumferential field coil has tilted, resulting in an error field.

[0111] By applying the solution of this application embodiment, the cause of the error field can be accurately determined by determining whether the circumferential field coil is tilted based on the direction of the equivalent circumferential current.

[0112] Corresponding to the above-described error field measurement method embodiments, this application also provides an error field measurement device embodiment. Figure 9 shows a schematic diagram of the structure of an error field measurement device provided in one embodiment of this application. As shown in Figure 9, the device includes:

[0113] The first acquisition module 902 is configured to acquire the electromotive force of the poloidal field coil collected by the sensor;

[0114] The first determining module 904 is configured to acquire test data for calibration testing of the error field measurement system, and determine the calibration test results based on the electromotive force and the test data;

[0115] The second determining module 906 is configured to acquire the voltage sensor signal of the poloidal field coil when the calibration test result indicates that the test has passed, and determine the poloidal magnetic flux of the poloidal field coil based on the voltage sensor signal and the electromotive force, wherein the voltage sensor signal is obtained based on the discharge operation of the circumferential field coil.

[0116] The third determining module 908 is configured to determine the error field measurement results of the circumferential field coil based on the pole magnetic flux.

[0117] In one embodiment, the first acquisition module 902 is further configured to acquire the coil type of the poloidal field coil; and acquire the electromotive force of the poloidal field coil collected by the sensor according to the coil type.

[0118] In one embodiment, the first acquisition module 902 is further configured to acquire the electromotive force of the poloidal field coil collected by the first sensor when the coil type is a series type. The first sensor and the poloidal field coil share a common ground. A target resistor is connected in series on the ground wire of the poloidal field coil. The two ends of the target resistor are connected to the target ground wire. The target ground wire is twisted with a voltage signal line that is not twisted with the ground wire. The target resistance is greater than the resistance of the wire.

[0119] In one embodiment, the poloidal field coil includes an active coil and a passive coil, the electromotive force is the electromotive force of the passive coil, and the test data includes the test current of the active coil; the first determining module 904 is further configured to determine the magnetic flux change index based on the test current; and determine the calibration test result based on the electromotive force and the magnetic flux change index.

[0120] In one embodiment, the second determining module 906 is further configured to determine the signal gain coefficient of the poloidal field coil based on the electromotive force; eliminate the zero-point drift of the voltage sensor signal to obtain the target signal; and determine the poloidal magnetic flux of the poloidal field coil according to the target signal and the signal gain coefficient.

[0121] In one embodiment, the device further includes: a second acquisition module configured to acquire the circumferential current of the circumferential field coil collected by the ammeter; and a third determination module 908 further configured to determine the error field measurement result of the circumferential field coil based on the polar magnetic flux when the polar magnetic flux is determined to be the error field magnetic flux based on the circumferential current.

[0122] In one embodiment, the third determining module 908 is further configured to determine the equivalent circumferential current of the circumferential field coil using the pole flux, wherein the simulated pole flux obtained by simulating the equivalent circumferential current matches the pole flux; and to determine the error field measurement result of the circumferential field coil based on the equivalent circumferential current.

[0123] In one embodiment, the error field measurement result includes the cause of the error field; the third determining module 908 is further configured to acquire the attribute information of the circumferential field coil; determine the torsion angle of the circumferential field coil based on the equivalent circumferential current and attribute information; and determine the cause of the error field coil as deformation of the circumferential field coil if the torsion angle does not meet the standard of the circumferential field coil.

[0124] In one embodiment, the error field measurement result includes the cause of the error field; the third determining module 908 is further configured to determine that the cause is the tilting of the circumferential field coil when the equivalent circumferential current is in the same direction.

[0125] The solution proposed in this application utilizes the poloidal field coil in a tokamak device to measure the error field of the circumferential field coil, eliminating the need for additional hardware components and reducing hardware costs and measurement complexity. Furthermore, the precise fabrication and accurate positioning of the poloidal field coil ensures its cross-section is precisely aligned with the poloidal direction, resulting in accurate and reliable measurement data and improving the accuracy of both the poloidal flux and error field measurement results.

[0126] The above is a schematic scheme of an error field measuring device according to this embodiment. It should be noted that the technical solution of this error field measuring device and the technical solution of the error field measuring method described above belong to the same concept. For details not described in detail in the technical solution of the error field measuring device, please refer to the description of the technical solution of the error field measuring method described above.

[0127] The foregoing has described specific embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0128] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the embodiments of this application are not limited to the described order of actions, because according to the embodiments of this application, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the embodiments of this application.

[0129] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0130] The preferred embodiments disclosed above are merely illustrative of this application. This application does not exhaustively describe all details, nor does it limit the invention to the specific embodiments described. Clearly, many modifications and variations can be made based on the content of the embodiments of this application. These embodiments are selected and specifically described in this application to better explain the principles and practical applications of the embodiments of this application, thereby enabling those skilled in the art to better understand and utilize this application. This application is limited only by the claims and their full scope and equivalents.

Claims

1. A method for measuring an error field, comprising: Acquire the electromotive force of the poloidal field coil collected by the sensor; Acquire test data for calibration testing of the error field measurement system, and determine the calibration test results based on the electromotive force and the test data; If the calibration test result indicates that the test has passed, the voltage sensor signal of the poloidal field coil is acquired, and the poloidal magnetic flux of the poloidal field coil is determined based on the voltage sensor signal and the electromotive force, wherein the voltage sensor signal is obtained based on the discharge operation of the circumferential field coil; as well as The error field measurement result of the circumferential field coil is determined based on the poloidal magnetic flux.

2. The method according to claim 1, wherein, The acquisition of the electromotive force of the poloidal field coil collected by the sensor includes: Obtain the coil type of the poloidal field coil; and Based on the coil type, the electromotive force of the poloidal field coil acquired by the sensor is obtained.

3. The method according to claim 2, wherein, The step of obtaining the electromotive force of the poloidal field coil acquired by the sensor according to the coil type includes: When the coil type is series type, the electromotive force of the poloidal field coil collected by the first sensor is obtained, wherein the first sensor and the poloidal field coil share a common ground, a target resistor is connected in series on the ground wire of the poloidal field coil, the two ends of the target resistor are connected to the target ground wire, the target ground wire is twisted with a voltage signal line that is not twisted with the ground wire, and the target resistance is greater than the resistance of the wire.

4. The method according to claim 1, wherein, The poloidal field coil includes an active coil and a passive coil, the electromotive force is the electromotive force of the passive coil, and the test data includes the test current of the active coil. The determination of the calibration test result based on the electromotive force and the test data includes: Based on the test current, determine the magnetic flux change index; and The calibration test results are determined based on the electromotive force and the magnetic flux change index.

5. The method according to claim 1, wherein, The determination of the poloidal magnetic flux of the poloidal field coil based on the voltage sensor signal and the electromotive force includes: Based on the electromotive force, the signal gain coefficient of the poloidal field coil is determined; Eliminate the zero-point drift of the voltage sensor signal to obtain the target signal; and The poloidal flux of the poloidal field coil is determined based on the target signal and the signal gain coefficient.

6. The method according to claim 1, wherein, Before determining the error field measurement result of the circumferential field coil based on the pole magnetic flux, the method further includes: Obtain the circumferential current of the circumferential field coil collected by the ammeter; The step of determining the error field measurement result of the circumferential field coil based on the poloidal magnetic flux includes: When the poloidal flux is determined to be the error field flux based on the circumferential current, the error field measurement result of the circumferential field coil is determined according to the poloidal flux.

7. The method according to claim 1, wherein, The step of determining the error field measurement result of the circumferential field coil based on the poloidal magnetic flux includes: Using the poloidal flux, the equivalent circumferential current of the circumferential field coil is determined, wherein the simulated poloidal flux obtained by simulating the equivalent circumferential current matches the poloidal flux; and The error field measurement result of the circumferential field coil is determined based on the equivalent circumferential current.

8. The method according to claim 7, wherein, The error field measurement results include the reasons for the generation of the error field; The step of determining the error field measurement result of the circumferential field coil based on the equivalent circumferential current includes: Obtain the attribute information of the circumferential field coil; Based on the equivalent circumferential current and the attribute information, the torsion angle of the circumferential field coil is determined; and If the torsion angle does not meet the standard for the circumferential field coil, the cause is determined to be deformation of the circumferential field coil.

9. The method according to claim 7, wherein, The error field measurement results include the reasons for the generation of the error field; The step of determining the error field measurement result of the circumferential field coil based on the equivalent circumferential current includes: When the equivalent circumferential current is in the same direction, the cause is determined to be the tilting of the circumferential field coil.

10. An error field measuring device, comprising: The first acquisition module is configured to acquire the electromotive force of the poloidal field coil collected by the sensor; The first determining module is configured to acquire test data for calibration testing of the error field measurement system, and determine the calibration test result based on the electromotive force and the test data; The second determining module is configured to, when the calibration test result indicates that the test has passed, acquire the voltage sensor signal of the poloidal field coil, and determine the poloidal magnetic flux of the poloidal field coil based on the voltage sensor signal and the electromotive force, wherein the voltage sensor signal is obtained based on a discharge operation on the circumferential field coil; as well as The third determining module is configured to determine the error field measurement result of the circumferential field coil based on the poloidal magnetic flux.

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