Ohm driving method and system for composite coil of copper conductor tokamak

Abstract

The invention discloses a composite coil ohm driving method of a copper conductor Tokamak, and belongs to the technical field of Tokamak magnetic field control. Giving a forming field coil discharge scheme with a zero field by taking a polar magnetic field at a geometric center as zero as a reference; measuring the ring voltage distribution on the wall of the vacuum chamber during breakdown by using an array formed by a plurality of single turns, compensating the eddy current on the wall by using a shaping field coil on the basis of the principle of minimum weighted ring voltage, and finally realizing that the vacuum chamber is in a zero field state during the breakdown period; during the plasma current driving period, the influence of the eddy current on the wall of the vacuum chamber on the plasma current measurement is compensated by measuring the current of the external coil; according to the method, original current distribution is not damaged during current driving by combining a distribution matrix of coil driving current, decoupling is carried out through mutual inductance matrixes among different coils, and cooperative control over the multiple coils is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of Tokamak magnetic field control, and in particular to an ohmic driving method and system for a composite coil of a copper conductor Tokamak. Background Art

[0002] Magnetic confinement nuclear fusion uses magnetic fields to confine high-energy plasma, allowing the ions inside to overcome Coulomb potential and fuse under the action of high temperature and high pressure. It is the most promising method for the peaceful use of thermonuclear fusion energy. Among the many types of magnetic confinement nuclear fusion devices, the tokamak device is the type of device closest to commercial fusion. The tokamak device is mainly used to obtain clean energy in the future. The magnetic field of the device is composed of toroidal magnetic field and poloidal magnetic field. The toroidal magnetic field is mainly generated by toroidal field coils, while the poloidal magnetic field is jointly generated by the plasma current in the plasma and the poloidal field coils outside the plasma. The plasma current is the basis of the tokamak magnetic confinement fusion plasma confinement. The poloidal field coil is composed of an ohmic coil and a forming field coil. The entire discharge process of the Tokamak is as follows: first, by rapidly changing the current in the Ohm coil and the forming field coil, a very strong ring voltage is formed in the inner area of ​​the vacuum chamber to break down the working gas, and a plasma is formed through the "avalanche effect". This stage is the plasma breakdown stage. During this stage, a very strong toroidal electric field must be generated in the vacuum chamber through electromagnetic induction, and the area where the plasma exists in the vacuum chamber must be in a zero field state during the "avalanche effect", that is, the polar magnetic field is almost zero, so as to greatly reduce the plasma loss during the "avalanche effect"; then comes the plasma current driving stage, during which the plasma current must be accurately controlled. Measurement and effective control. When measuring the plasma current, the magnetic field generated by the external coil, eddy currents on the vacuum chamber wall, etc. around it will seriously interfere with the measurement results. Therefore, to accurately measure the conductive gas current in the vacuum chamber, it is necessary to effectively deduct the influence of the external coil current and the eddy currents on the vacuum chamber wall. In addition, the plasma current distribution has a crucial influence on the operating state of the device and the macroscopic parameters of the plasma. Therefore, when driving the plasma current, it is necessary to consider not only the driving ability of the overall current, but also the influence of the current driving process on the plasma current distribution, or to keep the current distribution as unchanged as possible.

[0003] like Figure 1As shown, in a traditional copper conductor tokamak, the ohmic coil is composed of a central solenoid coil and multiple coils. The ohmic field coil is in a natural zero field state, that is, the coil will not generate a polar magnetic field in the central area of ​​the vacuum chamber. Moreover, the ohmic coil and the forming field coil are decoupled and can work independently of each other. The ohmic coil is used exclusively for driving the plasma current, and the forming field coil is used exclusively for controlling parameters such as the plasma shape. Traditional ohmic coil driving technology has the following disadvantages: First, the large number of coils increases the cost of device design, manufacturing and installation, and thus leads to complex coil / lead / cooling / support structure and great difficulty in maintenance; second, there is often a position conflict between the dispersed ohmic coils and the forming field coils, resulting in a close distance between the two, which not only brings about the problem of electrical insulation between the coils, but also the mutual electromagnetic force between these coils is huge. For a device with a megaampere plasma current, the mutual electromagnetic force often reaches thousands of tons, further deteriorating the implementation of coil support and posing a huge challenge to the safe operation of the coil; third, due to the increase in the actual number of turns of the ohmic coil and the increase in inductance, the control response rate of the coil power supply is reduced, the voltage level of the power supply is increased, and under the same current, the dispersed coils provide negative volt-seconds, which reduces the driving ability of the plasma current.

[0004] In response to the engineering problems faced by the above-mentioned traditional copper conductor tokamak forming field coils, the HL-3 tokamak device adopts a composite coil layout design, that is, the ohmic field coil only retains the central solenoid to efficiently drive the plasma current; the forming field coil needs to perform multiple tasks such as forming zero field, compensating eddy currents, and assisting in driving plasma current. Therefore, this design layout is called a composite coil layout. Figure 2 As shown, the poloidal field coil of the device is only composed of a central solenoid 2 and a plurality of shaping field coils 3. Among them, the central solenoid 2 is installed in the position closest to the high field side in the toroidal field coil 5, which is conducive to improving the driving ability of the plasma current. The shaping field coil 3 is distributedly installed in the cavity of the toroidal field coil 5, and is very close to the vacuum chamber 4 in structure. It has a strong control ability over the key parameters such as the shape and position of the plasma, and also provides plasma driving ability to a certain extent; the vacuum chamber 4, on the basis of ensuring the position of the coil, occupies the remaining space in the toroidal field coil 5 as much as possible to obtain a plasma with higher parameters; the toroidal field coil 5 provides the most important magnetic field for the confinement of the plasma in the device. The overall number of coils of the tokamak device with a composite coil layout is reduced, which makes it easier to implement the engineering of the poloidal field coil, and the magnetic field generated by the poloidal field coil is better in localization, which is more conducive to the implementation of plasma control, so that the tokamak device has a compact structure, high operating parameters, and great potential for improving plasma quality.

[0005] In the layout of the composite coil, the existence of the central solenoid will greatly interfere with the formation of the zero field, and the eddy current generated by the toroidal voltage on the vacuum chamber wall during plasma breakdown will also destroy the zero field, as well as the complex situations such as the strong coupling between the central solenoid and the forming field coil. Therefore, conventional control technology cannot be applied to the coordinated control scenario of this type of composite coil. Therefore, it is urgent to study a coordinated control method suitable for this type of composite coil to quickly and effectively realize the ohmic drive of the composite coil on the copper conductor tokamak device. Summary of the invention

[0006] Plasma control on a copper conductor tokamak with a composite coil layout faces the following challenges: the need to coordinate the generation of a zero field by each poloidal field coil (consisting of a central solenoid and multiple forming field coils) during the discharge breakdown phase; the need to accurately measure the plasma current during plasma current drive; the need to decouple the strongly coupled poloidal field coils and coordinately drive the plasma current; and the need to maintain the current distribution of the conductive gas in the vacuum chamber unchanged. The present application proposes a composite coil ohmic drive method and system for a copper conductor tokamak. The present application provides a shaped field coil discharge scheme with a zero field based on the distribution of magnetic fields generated by each shaped field coil and a central solenoid in a vacuum chamber region, taking the poloidal magnetic field at the geometric center as zero as a benchmark; an array composed of multiple single turns is used to measure the ring voltage distribution on the vacuum chamber wall during breakdown, and the eddy current on the wall is compensated by the shaped field coil based on the principle of minimum weighted ring voltage, so as to finally achieve a zero field state for the vacuum chamber during the breakdown period; during the plasma current driving period, the present application measures the influence of the composite coil current and the eddy current on the vacuum chamber wall on the plasma current measurement, and obtains the accurate value of the plasma current after deducting the above factors; based on the distribution of the plasma current, a distribution matrix of the poloidal field coil driving current is constructed to achieve driving current without destroying the original current distribution, and decouples through the mutual inductance matrix between different poloidal field coils to achieve effective control of the poloidal field coil, thereby driving the plasma current.

[0007] This application is implemented through the following technical solutions:

[0008] A composite coil ohmic driving method for a copper conductor tokamak, comprising:

[0009] According to the pre-configured current ratio of each forming field coil and the central solenoid, the central solenoid and each forming field coil are coordinated to ensure that the vacuum chamber is in a zero field state during plasma breakdown;

[0010] During the plasma current driving period, a plasma current measurement signal is acquired in real time, and the plasma current measurement signal is compensated by using the toroidal field coil current, the forming field coil current and the vacuum chamber eddy current to obtain a plasma current real signal;

[0011] According to the deviation value between the real signal of the plasma current and the expected signal of the plasma current, the total amount of ring voltage feedback control required for the plasma region is obtained based on the feedback control of the deviation value, and the feedback control amount of the central solenoid and each forming field coil is determined in combination with the allocation matrix and the decoupling matrix;

[0012] The total amount of ring voltage feedforward control required for the plasma region is calculated according to the plasma current expected signal, and the feedforward control amount of the central solenoid and each forming field coil is determined in combination with the allocation matrix and the decoupling matrix;

[0013] The feedback control amount of the central solenoid and each forming field coil is linearly superimposed with the corresponding feedforward control amount to obtain the control amount of the central solenoid and each forming field coil, and the central solenoid and each forming field coil are coordinated and controlled accordingly to achieve stable driving of the plasma current;

[0014] The allocation matrix is ​​used to ensure that the distribution of plasma current does not change when the coordinated control of the central plasma and each forming field coil is achieved; and the decoupling matrix contains the decoupling information of the central solenoid and each forming field coil.

[0015] In a second aspect, the present application proposes a composite coil ohmic drive system for a copper conductor tokamak, comprising:

[0016] A zero field module, wherein the zero field module is configured to: coordinately control the central solenoid and each forming field coil according to a pre-configured current ratio of the central solenoid and each forming field coil to ensure that the vacuum chamber is in a zero field state during plasma breakdown;

[0017] A measurement compensation module, wherein the measurement compensation module is configured to: during the plasma current driving period, acquire a plasma current measurement signal in real time, and compensate the plasma current measurement signal by using a toroidal field coil current, a forming field coil current, and a vacuum chamber eddy current to obtain a plasma current true signal;

[0018] A feedback control module, wherein the feedback control module is configured to: obtain the total amount of ring voltage feedback control required for the plasma region based on the deviation value between the real signal of the plasma current and the expected signal of the plasma current, and determine the feedback control amount of the central solenoid and each forming field coil in combination with the allocation matrix and the decoupling matrix;

[0019] A feedforward control module, wherein the feedforward control module is configured to: calculate the total amount of ring voltage feedforward control required for the plasma region according to the plasma current expected signal, and determine the feedforward control amount of the central solenoid and each forming field coil in combination with the allocation matrix and the decoupling matrix;

[0020] and an execution module, wherein the execution module is configured to: linearly superimpose the feedback control amount of the central solenoid and each forming field coil with the corresponding feedforward control amount to obtain the control amount of the central solenoid and each forming field coil, and coordinately control the central solenoid and each forming field coil accordingly to achieve stable driving of the plasma current;

[0021] The allocation matrix is ​​used to ensure that the distribution of plasma current does not change when the coordinated control of the central solenoid and each forming field coil is achieved; the decoupling matrix contains the decoupling information of the central solenoid and each forming field coil.

[0022] In a third aspect, the present application proposes an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0023] The present application proposes a composite coil ohmic drive method and system for a copper conductor tokamak. The ohmic drive mainly relies on a central solenoid, and the forming field coil can also provide ohmic drive capability to a certain extent. Compared with the traditional copper conductor tokamak driven by ohmic coils, the present application can transfer the control weight to other coils with ohmic drive capability when a certain coil is abnormal or fails. The plasma current can still be driven smoothly within a certain time range, which reserves enough time for taking soft landing shutdown measures and ensures the safe operation of the device.

[0024] The present application proposes an ohmic drive method and system for a composite coil of a copper conductor Tokamak, in which a central solenoid and a forming field coil with ohmic drive capability can all be located within the annular field coil, making the control of the plasma more flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the embodiments of the present application, constitute a part of the present application, and do not constitute a limitation on the embodiments of the present application. In the drawings:

[0026] Figure 1 It is a schematic diagram of the layout of the conventional plasma current driving coil;

[0027] Figure 2 This is a flow chart of the plasma current driving method according to an embodiment of the present application;

[0028] Figure 3 A schematic diagram of the layout of the plasma current drive coil used in the embodiment of the present application;

[0029] Figure 4 This is a principle block diagram of the plasma current driving system of an embodiment of the present application;

[0030] Figure 5 The plasma current driving method proposed in the embodiment of the present application is used to achieve a driving effect of a plasma current of 1MA.

[0031] Reference numerals and corresponding component names:

[0032] 1-Ohm coil, 2-central solenoid, 3-forming field coil, 4-vacuum chamber wall, 5-toroidal field coil, 6-divertor, 7-sector connector. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with examples and drawings. The illustrative implementation scheme of the present application and its description are only used to explain the present application and are not intended to limit the present application.

[0034] Example:

[0035] The ohmic field coils on the traditional copper conductor tokamak produce a natural zero field in the central area, and this zero field is largely decoupled from other forming field coils, so there is no need to consider the zero field problem during the breakdown stage. However, in the case of a composite coil layout, the central solenoid will interfere with the formation of the zero field to a great extent. For this reason, multiple forming field coils need to work together with the central solenoid to form and maintain the zero field, and the current in each coil changes synchronously to generate a toroidal electric field. When the plasma breaks down, the toroidal voltage reaches tens of volts, which can drive eddy currents of hundreds of thousands of amperes on the vacuum chamber wall, which is enough to destroy the zero field. Therefore, the eddy currents on the vacuum chamber wall must be compensated. What is more complicated is that although the magnetic field in the vacuum chamber can be regarded as quasi-toroidally symmetrical, the polar distribution is very asymmetric, which leads to uneven polar distribution of eddy currents on the vacuum chamber wall. In addition, the eddy currents on the vacuum chamber wall are driven by the ring voltage, but the differences in different polar positions of the vacuum chamber lead to the existence of time constants in the above current distribution, resulting in nonlinearity, which poses a great challenge to the measurement and compensation of eddy currents. Moreover, in the composite coil layout, each forming field coil and the central solenoid are in a state of strong coupling. The allocation and decoupling control of the functions of each coil are the difficult problems faced by the plasma control system of the composite coil Tokamak device. Based on this, this embodiment proposes an ohmic driving method for a composite coil of a copper conductor Tokamak. The composite coil ohmic driving method proposed in this embodiment uses a central solenoid and multiple forming field coils to collaboratively realize plasma current driving, specifically including: first, during plasma breakdown, based on each forming field coil and the central solenoid, a magnetic field distribution is generated in the vacuum chamber area, and a forming field coil discharge scheme with a zero field is given based on the zero polar magnetic field at the geometric center. An array composed of multiple single turns is used to measure the ring voltage distribution on the vacuum chamber wall during breakdown. Based on the principle of minimum weighted ring voltage, the forming field coil is used to compensate for the eddy current on the vacuum chamber wall, and finally the vacuum chamber is in a zero field state during breakdown; then, during plasma current driving, the forming field current is used to generate a magnetic field distribution in the vacuum chamber area. , the eddy current on the vacuum chamber wall compensates for the measurement signal to obtain an accurate plasma current value, based on the accurate plasma current value and the expected current value, feedback control is performed to obtain the total feedback control amount, based on the total feedback control amount and in combination with the allocation matrix and the decoupling matrix, the feedback control amount on the central solenoid and each forming field coil is obtained, and at the same time, according to the expected current value, the total feedforward control amount is calculated, based on the total feedforward control amount and in combination with the allocation matrix and the decoupling matrix, the feedforward control amount on the central solenoid and each forming field coil is obtained, finally, according to the feedback control amount on the central solenoid and each forming field coil and the corresponding feedforward control amount, the control amount on the central solenoid and each forming field coil is determined, and the coordinated control of the central solenoid and each forming field coil is performed accordingly.

[0036] like Figure 3 As shown, the plasma current driving method proposed in this embodiment specifically includes the following steps:

[0037] Step 100, according to the pre-configured current ratio of each forming field coil and the central solenoid, the central solenoid and each forming field coil are coordinated and controlled to ensure that the vacuum chamber is in a zero field state during plasma breakdown.

[0038] The plasma breakdown process requires that the polar magnetic field in the plasma formation region is very small, that is, a zero field region is formed, otherwise the breakdown plasma will be lost quickly, resulting in breakdown failure. Therefore, in the case of the layout of the composite coil, it is necessary to consider how to coordinate the control of the central solenoid and each forming field coil to ensure that the vacuum chamber is in a zero field state during the plasma breakdown.

[0039] An optional implementation method, taking into account the interference of the central solenoid on the zero field and the destruction of the zero field by the eddy current under the layout of the composite coil, this embodiment first uses multiple forming field coils to compensate the central solenoid, and then adjusts the current waveform of each forming field coil to compensate for the eddy current, thereby determining the optimal ratio of the central solenoid and each forming field coil current to achieve the vacuum chamber in a zero field state during plasma breakdown. The specific process includes:

[0040] Step 101, based on the magnetic field distribution generated by the central solenoid and each forming field coil in the vacuum chamber area, the discharge scheme of the forming field coil with the initial zero field is given with the polar magnetic field at the geometric center of the vacuum chamber area being zero as the benchmark. The specific process is as follows: using a magnetic probe array to measure the magnetic field distribution of the single-pass central solenoid and each forming field coil; based on the Biot-Saffar law, using the finite element analysis method to calculate the magnetic field distribution generated by the central solenoid and each forming field coil; using the measured magnetic field distribution to verify whether the calculated magnetic field distribution meets the requirements (that is, the magnetic field distribution calculated by the finite element analysis method is consistent with the actual or the deviation is within an acceptable range); if so, using the calculated magnetic field distribution of each forming field coil to compensate for the polar magnetic field generated by the calculated central solenoid, and configuring the ratio (ratio) of the current in each forming field coil and the current of the central solenoid with the polar magnetic field in the geometric center of the vacuum chamber being zero as the judgment basis, to form the discharge scheme of the forming field coil with the initial zero field;

[0041] Step 102, using an array composed of multiple single-turn rings to measure the ring voltage distribution on the vacuum chamber wall during breakdown, based on the principle of minimizing the weighted ring voltage, adjusting the initial zero-field forming field coil discharge scheme to compensate for the eddy current on the vacuum chamber wall, and determining the optimal zero-field forming field coil discharge scheme. The specific process is as follows: first, the ring voltage in a certain poloidal region of the vacuum chamber during the plasma breakdown is measured by a single-turn ring, and the self-inductance of the vacuum chamber wall in the region is calculated based on the spatial characteristic information of the single-turn ring. The decay curve of the ring voltage after the breakdown is fitted by an exponential function to obtain the characteristic time of the region, and then the resistance of the region is obtained; multiple single-turn rings can be used to measure the poloidal distribution of inductance and resistance on the vacuum chamber wall; the spatial size of the forming field coil is used to calculate the mutual inductance generated by the forming field coil to the vacuum chamber wall in its adjacent area; based on the measured eddy current distribution of the vacuum chamber wall, the poloidal magnetic flux distribution and time evolution curve required to compensate for the eddy current are inversely calculated, and the evolution curve of the current in each forming field coil is obtained accordingly; the single-turn ring is weighted according to the density of the single-turn ring, and the weighting coefficient is the inverse of the distance between two adjacent single-turn rings. The current waveform of each forming field coil is adjusted with the minimum weighted average value of the single-turn ring as an indicator to obtain the best eddy current compensation effect, thereby determining the forming field coil discharge scheme with the optimal zero field (i.e., the ratio of the forming field coil current to the central solenoid current). In subsequent practical applications, the current ratio of the central solenoid and the forming field coil determined above can be directly used to coordinately control them, so as to achieve a zero-field state in the vacuum chamber during plasma breakdown.

[0042] Step 200, during the plasma current driving period, a plasma current measurement signal is acquired in real time, and the plasma current measurement signal is compensated by using the toroidal field coil current, the forming field coil current and the vacuum chamber eddy current to obtain a plasma current real signal.

[0043] In the case of the layout of the composite coil, considering that the shaping field coil is arranged inside the toroidal field coil and is very close to the vacuum chamber wall, the eddy current on the vacuum chamber wall will seriously affect the measurement of the plasma current. Therefore, in order to obtain an accurate plasma current value, this embodiment compensates the plasma current measurement value to eliminate the influence of external interference on the measurement.

[0044] Specifically, step 200 also includes the following sub-steps:

[0045] Step 201, real-time acquisition of plasma current measurement signal. The plasma current in the tokamak device is usually measured by a Rocco coil, which is inside or outside the vacuum chamber and distributed along the polar direction of the tokamak device. The two ends of the Rocco coil are connected to the input end of the integrator. The original signal measured by the Rocco coil is integrated to obtain the plasma current measurement signal. The output end of the integrator is connected to the acquisition card to obtain the plasma current measurement signal. The plasma current measurement signal is the integral value of the polar magnetic field along the direction of the Rocco coil multiplied by the number of turns of the Rocco coil multiplied by the cross-sectional area of ​​the Rocco coil divided by the integration time.

[0046] Step 202, real-time acquisition of the toroidal field coil current and the currents of each forming field coil, and compensation of the plasma current measurement signal is performed once in combination with the influencing factors corresponding to the toroidal field coil and each forming field coil, to obtain a compensated plasma current measurement signal.

[0047] This step uses the Rocco coil and the integrator to measure the toroidal field coil current and each forming field coil current in real time, that is, a circle of Rocco coil is arranged along the circumference of the toroidal field coil and each forming field coil, and the two ends of the Rocco coil are connected to the input end of the integrator. The original signal measured by the Rocco coil is integrated to obtain the corresponding toroidal field coil or forming field coil current. The measurement principle is the same as that described in the above step 101, and will not be repeated here.

[0048] After the toroidal field coil current and the currents of each forming field coil are obtained in real time, the product of the toroidal field coil current and its influencing factor is taken as the interference current of the toroidal field coil, and the product of the forming field coil current and its influencing factor is taken as the interference current of the forming field coil. It should be noted that there are multiple forming field coils, and of course there are multiple influencing factors. Therefore, the product of the current of the forming field coil and its influencing factor is essentially the sum of the products of the currents of multiple forming field coils and their corresponding influencing factors as the interference current of the forming field coil. The interference currents of the toroidal field coil and the forming field coil are deducted (linearly added or subtracted) from the plasma current measurement signal to obtain the compensated plasma current measurement signal.

[0049] Among them, the influencing factors of the toroidal field coil and the forming field coil are determined specifically as follows: by passing a long-term steady current through the toroidal field coil and the forming field coil separately, that is, under stable field experimental conditions (at this time the central solenoid is not working, and the plasma current measurement value only represents the current generated in the vacuum chamber by the mutual inductance of the toroidal field coil or the forming field coil), by obtaining the ratio between the plasma current measurement value and the corresponding coil current, the corresponding influencing factor is obtained.

[0050] Step 203 , acquiring the eddy current on the vacuum chamber wall in real time, and performing secondary compensation on the compensated plasma current measurement signal in combination with the influence factor of the eddy current to obtain a real plasma current signal.

[0051] In this step, multiple single-turn rings are used to measure the ring voltages at different polar positions on the vacuum chamber wall. The eddy current at the corresponding polar position can be calculated based on the ring voltages obtained by real-time measurement of the single-turn rings and combined with the LR circuit model. The LR circuit model is expressed as:

[0052]

[0053] Among them, R is the resistance of eddy current, L is the self-inductance of eddy current, I is the eddy current, t is the time, and V is the ring voltage.

[0054] After obtaining the eddy currents at different polar positions, the sum of the products of the eddy currents and the corresponding influencing factors is taken as the eddy current interference current. The eddy current interference current is deducted (linearly added or subtracted) from the compensated plasma current measurement signal to obtain the true plasma current signal.

[0055] In an optional implementation, the LR circuit model is determined in the following way: using multiple single-turn rings to measure the ring voltage at different polar positions of the vacuum chamber wall, and using the Biot-Saffar law to calculate the self-inductance of the eddy current at each polar position under the assumption of quasi-circular symmetry. In the experimental case where the forming field coil rapidly reduces the current, the ring voltage measured by the single-turn ring decreases exponentially. The curve of the single-turn ring measurement value after the current of each forming field coil is reduced to zero is exponentially fitted to obtain the index and amplitude of the curve. The self-inductance at different polar positions is multiplied by the corresponding exponent to obtain the resistance of the eddy current in the polar position area. Based on the self-inductance and resistance, the LR circuit model of the eddy current is constructed:

[0056] An optional implementation manner, the influence factor of eddy current is determined specifically as follows: by passing an oscillating current through multiple forming field coils (i.e., in an oscillating field experiment, the central solenoid is not working at this time, i.e., the plasma current measurement value only represents the current generated in the vacuum chamber by the mutual inductance of the toroidal field coil and multiple forming field coils), and measuring the plasma current, toroidal field current, forming field current, and eddy current. The specific measurement method is as described above and will not be elaborated on this time; then, the corresponding forming field current measurement value and toroidal field current measurement value are deducted (linearly added or subtracted) from the plasma current measurement value to obtain the plasma current affected only by eddy currents; finally, based on the plasma current affected only by eddy currents and the measured eddy current, high-dimensional linear fitting is used to obtain the influence factor of eddy currents. Specifically, it can be expressed as:

[0057]

[0058] Where A is the eddy current factor at different polar positions, IP eddy is the plasma current affected only by eddy current at different time points, are the eddy currents at different polar positions and at different time points.

[0059] Step 300, according to the deviation value of the plasma current real signal and the plasma current expected signal, the total amount of ring voltage feedback control required for the plasma region is obtained based on the deviation value feedback control, and the feedback control amount of the central solenoid and each forming field coil is determined in combination with the allocation matrix and the decoupling matrix. The allocation matrix is ​​used to ensure that the distribution of the plasma current does not change when the central solenoid and each forming field coil are coordinated; and the decoupling matrix contains the decoupling information of the central solenoid and each forming field coil.

[0060] After obtaining the real signal of plasma current, it is compared with the expected signal of plasma current to obtain the deviation value between the two, and the PID controller is used to feedback control the deviation value to obtain the total amount of ring voltage control required for the plasma area. It should be noted that the PID controller can adopt a conventional PID controller to achieve the optimal control quantity output by adjusting parameters.

[0061] According to the plasma current driving principle, by changing the current of the central solenoid and each forming field coil, the magnetic flux in the vacuum chamber will change, thereby achieving the purpose of driving the plasma current. The relationship between the total amount of plasma ring voltage control and the voltage control amount of the central solenoid and each forming field coil can be expressed as:

[0062]

[0063] Where, ΔV p is the total amount of plasma ring voltage control; M pc The inverse matrix of ΔV represents the allocation matrix; c It is the voltage control quantity of the central solenoid and each forming field coil.

[0064] In an optional implementation manner, the calculation method of the allocation matrix specifically includes:

[0065] Step 301, discretize the plasma region into a plurality of current loops. For example, discretize the plasma region into 129×129 grids, each grid representing a current loop, which is referred to as Example 1 for ease of description.

[0066] Step 302: The mutual inductance matrix between the central solenoid, each shaping field coil and the plasma current loop is obtained by analyzing the Biot-Saffar law. Taking the above example 1 as an example, a mutual inductance matrix of 17×16641 can be obtained, where 16641 is the number of discrete current loops in the plasma region, and 17 is the number of the central solenoid and the shaping field coil.

[0067] Step 303, the inverse matrix of the mutual inductance matrix between the central solenoid, each forming field coil and the plasma current loop is calculated by an asymmetric inversion algorithm. That is, taking the above example 1 as an example, a 16641×17 inverse matrix can be obtained.

[0068] Step 304, multiply the plasma current distribution by the inverse matrix to calculate the distribution matrix. The distribution matrix can ensure that the distribution of the plasma current will not change when the plasma current changes. The calculation and execution of the distribution matrix reflects the synergy of the central solenoid and each forming field coil when driving the plasma. Among them, the plasma current distribution is obtained by: obtaining the measurement results of the boundary polar magnetic field under steady-state discharge experimental conditions, and using the high-order polynomial fitting of the plasma equilibrium to obtain the plasma current distribution. Specifically, the measurement results of the boundary polar magnetic field can be obtained by multiple boundary magnetic probes. Taking the above example one as an example, the plasma current distribution can be obtained as a row vector of 1×16641.

[0069] Since there is a very strong coupling between the central solenoid and the forming field coil, it is necessary to implement decoupling control between the central solenoid and the forming field coil, that is, when applying voltage to coordinately control the central solenoid and each forming field coil, it is necessary to consider not only the change in the resistance and inductance of the coil itself, but also the effect of the current change of other coils on it. In an optional implementation, the decoupling control process specifically includes:

[0070] Step 305, calculating the mutual inductance matrix between the central solenoid and each shaped field coil by Biot-Saffar law as a decoupling matrix;

[0071] Step 306, based on the total amount of loop voltage feedback control, the allocation matrix and the decoupling matrix, the feedback control amount of the central solenoid and each forming field coil can be obtained. Specifically, the total amount of loop voltage feedback control is multiplied by the allocation matrix and the decoupling matrix to obtain the feedback control amount. It should be noted that the feedback control amount here is the voltage control amount.

[0072] Step 400, based on the plasma current expected signal, calculate the total amount of ring voltage feedforward control required for the plasma region, and determine the feedforward control amount of the central solenoid and each forming field coil in combination with the allocation matrix and the decoupling matrix.

[0073] The plasma circuit equation is expressed as:

[0074]

[0075] Where V is the ring voltage in the plasma region; L p is the plasma self-inductance, which varies with different discharge conditions. However, since its variation range is generally not large, the plasma self-inductance can be estimated in advance. p is the real signal of plasma current; R p is the plasma internal resistance; M pc is the mutual inductance matrix from the plasma region to the poloidal field coil, which can be analytically obtained by the Biot-Saffar law; I c is the current in the poloidal field coil.

[0076] Based on the above equation, according to the expected signal of plasma current and the self-inductance and internal resistance of the plasma region, the total amount of ring voltage feedforward control required by the plasma region can be obtained. According to the total amount of feedforward control, combined with the allocation matrix and decoupling matrix obtained in the above step 300 (i.e., multiplying the total amount of feedforward control with the allocation matrix and the decoupling matrix), the feedforward control amount of the central solenoid and each forming field coil can be calculated. It should be noted that the feedforward control amount is also a voltage control amount.

[0077] In an optional implementation manner, the method for estimating plasma self-inductance specifically includes:

[0078] Step 401, the self-inductance of each current loop of the plasma and the mutual inductance between other current loops are calculated by the Biot-Saffar law to form a mutual inductance matrix. For example, taking the above example 1 as an example, a mutual inductance matrix of 16641×16641 can be obtained, where the diagonal terms are the self-inductance of each current loop and the non-diagonal terms are the mutual inductance between different current loops.

[0079] Step 402, using the parallel inductance model to calculate the self-inductance of the plasma region. The self-inductance calculation equation of the conductive gas region is expressed as:

[0080] L p =1 / (I pr M IP -1 [1])

[0081] Among them, I pr is the current distribution of the conductive gas, M IP is the mutual inductance matrix, [1] represents an n×1 column vector (all values ​​are 1), and n is the number of central solenoids and shaping field coils.

[0082] In an optional embodiment, the internal resistance of the plasma region can be determined by measuring the ratio of the ring voltage of the plasma region to the plasma current. Under stable discharge experimental conditions, the plasma region is mainly affected by resistance, so the internal resistance of the plasma region can be directly determined by the above method.

[0083] Step 500, linearly superimpose the feedback control quantity of the central solenoid and each forming field coil with its corresponding feedforward control quantity to obtain the control quantity of the central solenoid and each forming field coil, and coordinately control the central solenoid and each forming field coil accordingly to achieve smooth driving of the plasma current.

[0084] It should be noted that there is no sequential execution relationship between step 400 and steps 100 to 300, but a parallel execution relationship, that is, step 400 can be executed first, or later, or simultaneously.

[0085] The conventional copper conductor Tokamak plasma drive completely relies on the complex structure of the ohmic coils, and the ohmic coils at different positions are connected in series. If any link is abnormal, the plasma current cannot be driven smoothly, and may even induce rupture instantly, threatening the safe operation of the device. In the plasma current driving method proposed in this embodiment, the central solenoid and the forming field coil are controlled separately, and they work together to maintain the zero field state during the plasma breakdown and the smooth driving of the plasma current. That is, the central solenoid and the forming field coil can provide a certain degree of ohmic driving capability. Therefore, even if a certain coil fails, the control weight can be transferred to other coils with ohmic driving capability, and the plasma current can still be driven smoothly within a certain time range. Sufficient time can be reserved for taking soft landing shutdown measures to ensure the safe operation of the device.

[0086] Based on the same technical concept as above, this embodiment also proposes a composite coil ohmic drive system for a copper conductor Tokamak, such as Figure 4 As shown, the composite coil ohmic drive system proposed in this embodiment specifically includes:

[0087] The zero field module is configured to: coordinately control the central solenoid and each forming field coil according to the pre-configured current ratio of each forming field coil and the central solenoid to ensure that the vacuum chamber is in a zero field state during plasma breakdown. The configuration process of the current ratio of the central solenoid and each forming field coil is as described in the above step 100, and will not be repeated here.

[0088] The measurement compensation module is configured to: acquire the plasma current measurement signal in real time during the plasma current driving period, and compensate the plasma current measurement signal by using the toroidal field coil current, the forming field coil current and the vacuum chamber eddy current to obtain the plasma current true signal.

[0089] Feedback control module, the feedback control module is configured as follows: according to the deviation value of the real signal of the plasma current and the expected signal of the plasma current, based on the feedback control of the deviation value, the total amount of ring voltage feedback control required for the plasma area is obtained, and the feedback control amount of the central solenoid and each forming field coil is determined in combination with the allocation matrix and the decoupling matrix. Among them, the allocation matrix is ​​used to ensure that the distribution of the plasma current does not change when the coordinated control of the central solenoid and each forming field coil is realized; and the decoupling matrix contains the decoupling information of the central solenoid and each forming field coil. It should be noted that the specific implementation process of the feedback control module is as described in the above step 300, which will not be repeated here.

[0090] A feedforward control module is configured to calculate the total amount of ring voltage feedforward control required for the plasma region according to the plasma current expected signal, and determine the feedforward control amount of the central solenoid and each forming field coil in combination with the allocation matrix and the decoupling matrix. It should be noted that the specific implementation process of the feedforward control module is as described in the above step 400, which will not be repeated here.

[0091] And, an execution module, which is configured to: linearly superimpose the feedback control quantity of the central solenoid and each forming field coil with the corresponding feedforward control quantity to obtain the control quantity of the central solenoid and each forming field coil, and coordinately control the central solenoid and each forming field coil accordingly to achieve smooth driving of the plasma current.

[0092] In an optional implementation manner, the measurement compensation module further includes:

[0093] A signal acquisition unit is configured to acquire in real time a plasma current measurement signal, a toroidal field coil current, currents of each forming field coil and an eddy current.

[0094] The first compensation unit is configured to: compensate the plasma current measurement signal once according to the toroidal field coil current and the currents of each forming field coil, and in combination with the influencing factors corresponding to the toroidal field coil and each forming field coil, to obtain a compensated plasma current measurement signal.

[0095] And, a second compensation unit is configured to: perform secondary compensation on the compensated plasma current measurement signal according to the eddy current on the vacuum chamber wall and in combination with the influence factor of the eddy current to obtain a true plasma current signal.

[0096] It should be noted that the specific implementation process of each module unit in the compensation module is as described in the above steps 201 to 203, and will not be repeated here.

[0097] The plasma current driving method proposed in this embodiment is used to drive the plasma current of the HL-3 device, and the plasma current is obtained. Figure 5 The results of the HL-3 device 4077 gun discharge experiment are shown. During the HL-3 device 4077 gun discharge experiment, breakdown, plasma current formation and early climb were achieved through the central solenoid and the forming field coil using the composite coil driving technology. In the figure, IP_VV_2M represents the true value of the plasma current, Vloop_2M represents the ring voltage applied to the plasma, I_CS1_2M represents the central solenoid discharge current, I_PF6B_1 and I_PF6A_1 represent the discharge current of a group of forming field coils PF6B and PF6A respectively, and I_PF8B_1 and I_PF8A_1 represent the discharge current of a group of forming field coils PF8B and PF8A respectively.

[0098] As can be seen from the figure: the technology of plasma current drive achieved by coordinated control of the central solenoid and the forming field coil can achieve stable drive of plasma current of one million amperes, and keep the polar magnetic field voltage at zero during the drive process. It can be seen that the plasma current drive method proposed in this embodiment reduces the number of overall coils of the tokamak device and the difficulty of engineering implementation compared to the ohmic drive technology used in the traditional copper conductor tokamak device, and can effectively achieve stable drive of plasma current. In addition, the central solenoid is mainly used to provide ohmic drive, and its current variation range is the largest, ranging from +60kA to about -40kA. Moreover, during the time period of 0.6 to 0.8 s, the current of the central solenoid is always zero, and no ohmic driving capability is provided. If the ohmic coil driving method of the traditional copper conductor tokamak is used, the plasma current will drop rapidly or even break at this time. However, by adopting the plasma current driving method proposed in this embodiment, when the central solenoid cannot provide the ohmic driving capability, the control weight of the ohmic driving is transferred to the other two groups of forming field coils. By changing the current size of the forming field coil during the time period of 0.6 to 0.8 s, not only the smooth rise of the plasma current is maintained, but also a stable divertor configuration discharge of one million amperes is achieved.

[0099] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0100] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0101] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0102] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0103] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only the specific implementation method of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A composite coil ohmic driving method for a copper conductor Tokamak, characterized in that: include: According to the pre-configured current ratio of each forming field coil and the central solenoid, the central solenoid and each forming field coil are coordinated to ensure that the vacuum chamber is in a zero field state during plasma breakdown; During the plasma current driving period, a plasma current measurement signal is acquired in real time, and the plasma current measurement signal is compensated by using the toroidal field coil current, the forming field coil current and the vacuum chamber eddy current to obtain a plasma current real signal; According to the deviation value between the real signal of the plasma current and the expected signal of the plasma current, the total amount of ring voltage feedback control required for the plasma region is obtained based on the feedback control of the deviation value, and the feedback control amount of the central solenoid and each forming field coil is determined in combination with the allocation matrix and the decoupling matrix; The total amount of ring voltage feedforward control required for the plasma region is calculated according to the plasma current expected signal, and the feedforward control amount of the central solenoid and each forming field coil is determined in combination with the allocation matrix and the decoupling matrix; The feedback control amount of the central solenoid and each forming field coil is linearly superimposed with the corresponding feedforward control amount to obtain the control amount of the central solenoid and each forming field coil, and the central solenoid and each forming field coil are coordinated and controlled accordingly to achieve stable driving of the plasma current; The allocation matrix is ​​used to ensure that the distribution of plasma current does not change when the coordinated control of the central plasma and each forming field coil is achieved; and the decoupling matrix contains the decoupling information of the central solenoid and each forming field coil.

2. The ohmic driving method of a composite coil of a copper conductor Tokamak according to claim 1, characterized in that: The configuration process of the current ratio of the central solenoid and each forming field coil specifically includes: Based on the magnetic field distribution generated by the central solenoid and each forming field coil in the vacuum chamber area, a forming field coil discharge scheme with an initial zero field is given with the poloidal magnetic field at the geometric center of the vacuum chamber area being zero as a reference; An array composed of multiple single-turn rings is used to measure the ring voltage distribution on the vacuum chamber wall during breakdown. Based on the principle of minimizing the weighted ring voltage, the discharge scheme of the forming field coil with the initial zero field is adjusted to compensate for the eddy current on the vacuum chamber wall, and the discharge scheme of the forming field coil with the optimal zero field is determined.

3. The ohmic driving method of a composite coil of a copper conductor Tokamak according to claim 2, characterized in that: The formation process of the initial zero-field forming field coil discharge scheme specifically includes: The magnetic field distribution when measuring the single-pass central solenoid and each shaped field coil is measured using a magnetic probe array; Based on the Biot-Saffar law, the magnetic field distribution generated by the central solenoid and each forming field coil is calculated using the finite element analysis method; Use the measured magnetic field distribution to verify whether the calculated magnetic field distribution meets the requirements. If yes, continue with the subsequent steps; otherwise, return to the previous step and recalculate; The calculated magnetic field distribution of each forming field coil is used to compensate for the calculated polar magnetic field generated by the central solenoid. The ratio of the current in each forming field coil and the central solenoid current is configured based on the judgment that the polar magnetic field in the geometric center area is zero, forming a forming field coil discharge scheme with an initial zero field.

4. The ohmic driving method of a composite coil of a copper conductor Tokamak according to claim 2, characterized in that: The formation process of the optimal zero-field forming field coil discharge scheme specifically includes: The ring voltage in a certain polar region of the vacuum chamber during plasma breakdown is measured by a single-turn ring, and the self-inductance of the vacuum chamber wall in the region is calculated based on the spatial characteristic information of the single-turn ring. The decay curve of the ring voltage after breakdown is fitted using an exponential function to obtain the characteristic time of the region, and then the resistance of the region is obtained; multiple single-turn rings can be used to measure the polar distribution of inductance and resistance on the vacuum chamber wall; The mutual inductance of the shaped field coil to the vacuum chamber wall in the vicinity thereof is calculated by using the spatial dimensions of the shaped field coil; Based on the measured eddy current distribution of the vacuum chamber wall, the poloidal magnetic flux distribution and time evolution curve required to compensate the eddy current are inversely calculated, and the evolution curve of the current in each forming field coil is obtained accordingly; The single-turn loops are weighted according to their density. The weighting coefficient is the inverse of the distance between two adjacent single-turn loops. Taking the minimum weighted average value of the single-turn loops as an indicator, the current waveform of each forming field coil is adjusted to obtain the best eddy current compensation effect, thereby determining the forming field coil discharge scheme with the optimal zero field.

5. The ohmic driving method of a composite coil of a copper conductor Tokamak according to claim 1, characterized in that: The calculation method of the allocation matrix specifically includes: Discrete the plasma region into a number of current loops; The first mutual inductance matrix between the central solenoid, each shaped field coil and the plurality of current loops is obtained by analyzing the Biot-Saffar law; Obtaining an inverse matrix of the first mutual inductance matrix by calculating through an asymmetric inversion algorithm; The plasma current distribution is multiplied by the inverse matrix to calculate the allocation matrix.

6. The ohmic driving method for a composite coil of a copper conductor Tokamak according to claim 5, characterized in that: The decoupling matrix is ​​specifically a mutual inductance matrix between the central solenoid and each forming field coil calculated by the Biot-Saffar law; The feedback control quantities of the central solenoid and each forming field coil can be obtained by multiplying the total loop voltage feedback control quantity with the allocation matrix and the decoupling matrix.

7. The ohmic driving method for a composite coil of a copper conductor Tokamak according to claim 5, characterized in that: The decoupling matrix is ​​specifically a mutual inductance matrix between the central solenoid and each forming field coil calculated by the Biot-Saffar law; The feedforward control amount of the central solenoid and each forming field coil can be obtained by multiplying the total amount of the loop voltage feedforward control with the allocation matrix and the decoupling matrix.

8. The ohmic driving method for a composite coil of a copper conductor Tokamak according to claim 7, characterized in that: The calculation method of the total amount of loop voltage feedforward control specifically includes: Calculating the total amount of ring voltage feedforward control required for the plasma region according to the plasma current expected signal and the self-inductance and internal resistance of the plasma region; The method for estimating the self-inductance of the plasma region specifically includes: The self-inductance of each current loop and the mutual inductance with other current loops are calculated by Biot-Saffar law to form a second mutual inductance matrix, wherein the diagonal items of the second mutual inductance matrix are the self-inductance of each current loop, and the non-diagonal items are the mutual inductances between different current loops; The self-inductance of the plasma region is calculated using a parallel inductance model; The method for estimating the internal resistance of the plasma region specifically includes: Under stable discharge experimental conditions, measuring the ring voltage of the plasma region and the plasma current; The ratio of the ring voltage to the plasma current in the plasma region is obtained as the internal resistance of the plasma region.

9. The ohmic driving method for a composite coil of a copper conductor Tokamak according to any one of claims 1 to 8, characterized in that: The method of compensating the plasma current measurement signal by using the toroidal field coil current, the poloidal field coil current and the vacuum chamber eddy current specifically includes: Acquire plasma current measurement signals in real time; Acquire the toroidal field coil current and each forming field coil current in real time, and compensate the plasma current measurement signal once in combination with the influencing factors corresponding to the toroidal field coil and each forming field coil, so as to obtain a compensated plasma current measurement signal; The eddy current on the vacuum chamber wall is acquired in real time, and the compensated plasma current measurement signal is secondary compensated in combination with the influence factor of the eddy current to obtain the real plasma current signal.

10. The ohmic driving method of a composite coil of a copper conductor Tokamak according to claim 9, characterized in that: The once compensating the plasma current measurement signal specifically includes: Real-time measurement to obtain the toroidal field coil current and each forming field coil current; The product of the toroidal field coil current and its influence factor is used as the interference current of the toroidal field coil, and the sum of the products of the currents of each shaping field coil and their corresponding influence factors is used as the interference current of the shaping field coil; Deducting the interference current of the toroidal field coil and the interference current of the forming field coil from the plasma current measurement signal to obtain a compensated plasma current measurement signal; The method for determining the influence factors of the annular field coil and each of the shaping field coils is: By passing a stable current into the annular field coil and each of the forming field coils separately, and measuring the corresponding toroidal field coil current and each of the forming field coil currents and their corresponding plasma current values; The ratio between the plasma current value and the corresponding coil current is taken as the influence factor of the coil.

11. The ohmic driving method of a composite coil of a copper conductor Tokamak according to claim 9, characterized in that: The secondary compensation of the compensated plasma current measurement signal specifically includes: The ring voltage at different polar positions of the vacuum chamber wall is measured in real time, and the eddy current at the corresponding polar position is calculated by combining the LR circuit model; wherein the LR circuit model characterizes the relationship between the ring voltage and the self-inductance and resistance of the eddy current; The sum of the products of the ring voltage at each polar position and its corresponding influence factor is taken as the interference current of the eddy current; Deducting the interference current of the eddy current from the compensated plasma current measurement signal to obtain the real plasma current signal; The influencing factor of the eddy current is determined as follows: By passing an oscillating current through the plurality of shaping field coils, and measuring corresponding plasma current, toroidal field current, shaping field current and eddy current; Deducting the corresponding shaping field current measurement value and the toroidal field current measurement value from the plasma current measurement value to obtain the plasma current affected only by the eddy current; According to the plasma current only affected by the eddy current and the measured value of the eddy current, the influence factor of the eddy current is obtained by using high-dimensional linear fitting.

12. A composite coil ohmic drive system for a copper conductor tokamak, characterized in that: include: A zero field module, wherein the zero field module is configured to: coordinately control the central solenoid and each forming field coil according to a pre-configured current ratio of the central solenoid and each forming field coil to ensure that the vacuum chamber is in a zero field state during plasma breakdown; A measurement compensation module, wherein the measurement compensation module is configured to: during the plasma current driving period, acquire a plasma current measurement signal in real time, and compensate the plasma current measurement signal by using a toroidal field coil current, a forming field coil current, and a vacuum chamber eddy current to obtain a plasma current true signal; A feedback control module, wherein the feedback control module is configured to: obtain the total amount of ring voltage feedback control required for the plasma region based on the deviation value between the real signal of the plasma current and the expected signal of the plasma current, and determine the feedback control amount of the central solenoid and each forming field coil in combination with the allocation matrix and the decoupling matrix; A feedforward control module, wherein the feedforward control module is configured to: calculate the total amount of ring voltage feedforward control required for the plasma region according to the plasma current expected signal, and determine the feedforward control amount of the central solenoid and each forming field coil in combination with the allocation matrix and the decoupling matrix; and an execution module, wherein the execution module is configured to: linearly superimpose the feedback control amount of the central solenoid and each forming field coil with the corresponding feedforward control amount to obtain the control amount of the central solenoid and each forming field coil, and coordinately control the central solenoid and each forming field coil accordingly to achieve stable driving of the plasma current; The allocation matrix is ​​used to ensure that the distribution of plasma current does not change when the coordinated control of the central solenoid and each forming field coil is achieved; the decoupling matrix contains the decoupling information of the central solenoid and each forming field coil.

13. The composite coil ohmic drive system of a copper conductor Tokamak according to claim 12, characterized in that: The compensation module also includes: A signal acquisition unit, wherein the signal acquisition unit is configured to: acquire in real time a plasma current measurement signal, a toroidal field coil current, currents of each forming field coil, and an eddy current current on a vacuum chamber wall; A first compensation unit, wherein the first compensation unit is configured to: perform a compensation on the plasma current measurement signal according to the toroidal field coil current and the currents of the respective shaping field coils, and in combination with the influencing factors corresponding to the toroidal field coil and the respective shaping field coils, to obtain a compensated plasma current measurement signal; And, a second compensation unit, wherein the second compensation unit is configured to: perform secondary compensation on the compensated plasma current measurement signal according to the eddy current on the vacuum chamber wall and in combination with the influence factor of the eddy current to obtain the plasma current true signal.

14. The composite coil ohmic drive system of a copper conductor Tokamak according to claim 12, characterized in that: The configuration process of the current ratio of the central solenoid and each forming field coil specifically includes: Based on the magnetic field distribution generated by the central solenoid and each forming field coil in the vacuum chamber area, a forming field coil discharge scheme with an initial zero field is given with the poloidal magnetic field at the geometric center of the vacuum chamber area being zero as a reference; An array composed of multiple single-turn rings is used to measure the ring voltage distribution on the vacuum chamber wall during breakdown. Based on the principle of minimizing the weighted ring voltage, the discharge scheme of the forming field coil with the initial zero field is adjusted to compensate for the eddy current on the vacuum chamber wall, and the discharge scheme of the forming field coil with the optimal zero field is determined.

15. The composite coil ohmic drive system of a copper conductor Tokamak according to claim 12, characterized in that: The calculation method of the allocation matrix specifically includes: Discrete the plasma region into a number of current loops; The first mutual inductance matrix between the central solenoid, each shaped field coil and the plurality of current loops is obtained by analyzing the Biot-Saffar law; Obtaining an inverse matrix of the first mutual inductance matrix by calculating through an asymmetric inversion algorithm; The plasma current distribution is multiplied by the inverse matrix to calculate the allocation matrix.

16. The composite coil ohmic drive system of a copper conductor Tokamak according to claim 15, characterized in that: The decoupling matrix is ​​specifically a mutual inductance matrix between the central solenoid and each forming field coil calculated by the Biot-Saffar law; The feedback control quantities of the central solenoid and each forming field coil can be obtained by multiplying the total loop voltage feedback control quantity with the allocation matrix and the decoupling matrix.

17. The composite coil ohmic drive system of a copper conductor Tokamak according to claim 15, characterized in that: The decoupling matrix is ​​specifically a mutual inductance matrix between the central solenoid and each forming field coil calculated by the Biot-Saffar law; The feedforward control amount of the central solenoid and each forming field coil can be obtained by multiplying the total amount of the loop voltage feedforward control with the allocation matrix and the decoupling matrix.

18. The composite coil ohmic drive system of a copper conductor Tokamak according to claim 17, characterized in that: The calculation method of the total amount of loop voltage feedforward control specifically includes: Calculating the total amount of ring voltage feedforward control required for the plasma region according to the plasma current expected signal and the self-inductance and internal resistance of the plasma region; The method for estimating the self-inductance of the plasma region specifically includes: The self-inductance of each current loop and the mutual inductance with other current loops are calculated by Biot-Saffar law to form a second mutual inductance matrix, wherein the diagonal items of the second mutual inductance matrix are the self-inductance of each current loop, and the non-diagonal items are the mutual inductances between different current loops; The self-inductance of the plasma region is calculated using a parallel inductance model; The method for estimating the internal resistance of the plasma region specifically includes: Under stable discharge experimental conditions, measuring the ring voltage of the plasma region and the plasma current; The ratio of the ring voltage to the plasma current in the plasma region is obtained as the internal resistance of the plasma region.

19. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 11 are implemented.

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