Hot cathode filament discharge control method and system and controllable nuclear fusion equipment

Abstract

The invention relates to the technical field of plasma discharge control, in particular to a hot cathode filament discharge control method and system and controllable nuclear fusion equipment, and the method comprises the steps: obtaining a target arc current value and target discharge time of a hot cathode filament, and calculating a voltage feed-forward value of the hot cathode filament according to the target arc current value and the target discharge time; in response to a discharge control instruction of the thermionic cathode filament, calculating a voltage feedback value of the thermionic cathode filament according to the actual arc current value and the target arc current value of the thermionic cathode filament; and controlling the hot cathode filament to discharge according to the voltage feed-forward value and the voltage feedback value. Therefore, the problems that when the hot cathode filament discharges, due to the fact that the thermal inertia of the filament is large and a control method in the related technology is difficult to adapt to parameter changes under different discharge conditions, plasma discharge response is slow, and adaptability is poor are solved.

Description

Technical Field

[0001] This application relates to the field of plasma discharge control technology, and in particular to a hot cathode filament discharge control method, system, and controllable nuclear fusion device. Background Technology

[0002] When an electric current is applied to a thermionic cathode filament, electrons are excited. These electrons collide with hydrogen gas to generate thermionic cathode plasma. However, during discharge, the thermionic cathode filament has a large thermal inertia and cannot adapt to parameter changes under different discharge conditions. Therefore, the thermionic cathode plasma discharge response is slow and has poor adaptability. Summary of the Invention

[0003] This application provides a hot cathode filament discharge control method, system, and controllable nuclear fusion device to solve the problems of slow plasma discharge response and poor adaptability caused by the large thermal inertia of the filament and the difficulty of adapting the control methods in related technologies to parameter changes under different discharge conditions.

[0004] The first aspect of this application provides a hot cathode filament discharge control method, comprising the following steps: obtaining a target arc current value and a target discharge time of the hot cathode filament; calculating a voltage feedforward value of the hot cathode filament based on the target arc current value and the target discharge time; responding to a discharge control command of the hot cathode filament; calculating a voltage feedback value of the hot cathode filament based on the actual arc current value and the target arc current value; and controlling the discharge of the hot cathode filament based on the voltage feedforward value and the voltage feedback value.

[0005] Optionally, the voltage feedforward value of the hot cathode filament is calculated based on the target arc current value and the target discharge time, including: calling a pre-established feedforward control model, which includes a mapping function between the target arc current value and the steady-state voltage and a time compensation function for the hot cathode filament; inputting the target arc current value and the target discharge time into the feedforward control model, and outputting the voltage feedforward value of the hot cathode filament through the feedforward control model.

[0006] Optionally, before calling the pre-established feedforward control model, the method further includes: acquiring first experimental data of the hot cathode filament under different target arc current values, the first experimental data including the steady-state voltage corresponding to each target arc current value; acquiring second experimental data of the hot cathode filament under different target discharge times, the second experimental data including the measured voltage corresponding to each target discharge time; generating a mapping function between the target arc current value and the steady-state voltage based on the first experimental data; generating a time compensation function for the hot cathode filament based on the second experimental data; and establishing a feedforward control model based on the mapping function and the time compensation function.

[0007] Optionally, the voltage feedback value of the hot cathode filament is calculated based on the actual arc current value and the target arc current value, including: calculating the deviation between the actual arc current value and the target arc current value; and calculating the voltage feedback value of the hot cathode filament based on the deviation value.

[0008] Optionally, the voltage feedback value of the hot cathode filament is calculated based on the deviation value, including: inputting the deviation value into the controller of the hot cathode filament, and outputting the voltage feedback value of the hot cathode filament through the controller. The controller includes a differential structure, a filter, and a saturation mechanism. The differential term corresponding to the differential structure acts on the actual arc current value, the filter is used to filter the target arc current value, and the saturation mechanism is used to stop the integral accumulation when the voltage feedback value reaches a preset limit value.

[0009] Optionally, the control formula for the controller is:

[0010] Where u(t) is the output of the controller; e(t) is the deviation between the target arc flow value and the actual arc flow value; and y(t) is the actual arc flow value. This is the proportionality coefficient; The integral coefficient; is the differential coefficient.

[0011] Optionally, controlling the discharge of the hot cathode filament based on the voltage feedforward value and the voltage feedback value includes: calculating a voltage control value based on the voltage feedforward value and the voltage feedback value; and controlling the power supply output voltage of the hot cathode filament based on the voltage control value.

[0012] Optionally, calculating the voltage control value based on the voltage feedforward value and the voltage feedback value includes: obtaining a first weighting coefficient of the voltage feedforward value and a second weighting coefficient of the voltage feedback value, wherein the first weighting coefficient is greater than the second weighting coefficient; calculating a first product of the voltage feedforward value and the first weighting coefficient; calculating a second product of the voltage feedback value and the second weighting coefficient; and calculating the voltage control value based on the first product and the second product.

[0013] A second aspect of this application provides a hot cathode filament discharge control system, comprising: a first calculation module for acquiring a target arc current value and a target discharge time of the hot cathode filament, and calculating a voltage feedforward value of the hot cathode filament based on the target arc current value and the target discharge time; a second calculation module for responding to a discharge control command of the hot cathode filament, and calculating a voltage feedback value of the hot cathode filament based on the actual arc current value and the target arc current value; and a control module for controlling the discharge of the hot cathode filament based on the voltage feedforward value and the voltage feedback value.

[0014] A third aspect of this application provides a controllable nuclear fusion device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the program to implement the hot cathode filament discharge control method as described in the above embodiments.

[0015] Therefore, this application has at least the following beneficial effects: This application embodiment can obtain the target arc current value and target discharge time of the hot cathode filament, calculate the voltage feedforward value of the hot cathode filament based on the target arc current value and target discharge time, and respond to the discharge control command of the hot cathode filament by calculating the voltage feedback value of the hot cathode filament based on the actual arc current value and target arc current value. Thus, the discharge of the hot cathode filament can be controlled according to the voltage feedforward value and voltage feedback value. The feedforward control provides a control quantity, thereby shortening the arc current establishment time and achieving a rapid response of the filament discharge. Furthermore, parameters can be flexibly adjusted according to different discharge conditions, effectively improving adaptability. Therefore, it solves the problems of slow plasma discharge response and poor adaptability caused by the large thermal inertia of the filament and the difficulty of adapting control methods in related technologies to parameter changes under different discharge conditions during hot cathode filament discharge.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a hardware structure diagram of hot cathode filament discharge control according to an embodiment of this application; Figure 2 This is a flowchart of a hot cathode filament discharge control method provided according to an embodiment of this application; Figure 3 This is a schematic diagram illustrating the correspondence between arc flow value and time according to an embodiment of this application; Figure 4 This is a detailed flowchart of hot cathode filament discharge control according to an embodiment of this application; Figure 5 This is a structural diagram of the hot cathode filament discharge control system provided according to an embodiment of this application; Figure 6 This is a schematic diagram of the structure of a controlled nuclear fusion device provided according to an embodiment of this application. Detailed Implementation

[0018] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. Hot cathode filament discharge devices typically need to quickly establish a stable arc current within a few seconds. However, the control methods in related technologies mainly adopt PID (Proportional-Integral-Derivative Control) feedback control. Due to the large thermal inertia of the filament, the response speed is slow, and the arc current establishment usually takes several seconds or even longer, which cannot meet the requirements of rapid discharge. Severe overshoot is prone to occur in the early stage of arc current establishment. For example, when the target arc current is 10 A, the actual arc current may momentarily surge to 17 A before falling back, which may lead to filament overheating and damage or plasma instability. There are various random disturbances during the discharge process. The anti-interference ability of PID in related technologies is poor, resulting in large arc current fluctuations. PID controllers with fixed parameters have poor adaptability and are difficult to cope with parameter changes under different discharge conditions, requiring frequent manual parameter adjustment, etc.

[0019] The hardware architecture for hot cathode filament discharge control includes a control interface, control chassis, filament power supply, arc power supply, filament, and ion source arc chamber, such as... Figure 1 As shown, the control interface is used to set parameters and send commands to the control box. The control box outputs the filament voltage set value to the filament power supply to drive the filament heating. The filament is placed in the ion source arc chamber, and the electrons emitted by it collide with the hydrogen gas in the arc chamber to generate plasma. At the same time, the control box receives the arc flow feedback signal from the arc power supply to realize closed-loop control of the plasma arc flow.

[0020] The PID control formula in related technologies is as follows: e(t) = r(t) y(t)

[0021] Where u(t) is the output of the PID controller; e(t) is the error; r(t) is the set target arc flow value; and y(t) is the actual arc flow value. This is the proportionality coefficient; The integral coefficient; is the differential coefficient.

[0022] As shown in the formula above, when the setpoint r(t) undergoes a step change (from 0 to R), if the controlled variable y(t) has not yet responded, the error e(t) will jump instantaneously from 0 to R. This results in an extremely high spike pulse in the differential term output. Therefore, the filament cannot respond instantaneously due to thermal inertia, but the filament has already output excessive voltage, inevitably leading to a large overshoot. The system needs a long time to recover from the overshoot, resulting in a prolonged settling time.

[0023] The following describes a hot cathode filament discharge control method, system, and controllable nuclear fusion device according to embodiments of this application, with reference to the accompanying drawings. Addressing the problems of slow arc current establishment and large overshoot caused by the thermal inertia of the filament during hot cathode filament discharge, as mentioned in the background art, this application provides a hot cathode filament discharge control method. In this method, the target arc current value and target discharge time of the hot cathode filament are obtained; a voltage feedforward value of the hot cathode filament is calculated based on the target arc current value and target discharge time; in response to the discharge control command of the hot cathode filament, a voltage feedback value of the hot cathode filament is calculated based on the actual arc current value and target arc current value. Thus, the hot cathode filament discharge can be controlled based on the voltage feedforward value and voltage feedback value. By providing control quantity through feedforward control, the arc current establishment time is shortened, achieving rapid response of the filament discharge. Furthermore, parameters can be flexibly adjusted according to different discharge conditions, effectively improving adaptability. Therefore, this solves the problems of slow plasma discharge response and poor adaptability caused by the large thermal inertia of the filament and the difficulty of adapting control methods in related technologies to parameter changes under different discharge conditions during hot cathode filament discharge.

[0024] Specifically, Figure 2 This is a flowchart of a hot cathode filament discharge control method provided in an embodiment of this application.

[0025] like Figure 2 As shown, the hot cathode filament discharge control method includes the following steps: In step S201, the target arc current value and target discharge time of the hot cathode filament are obtained, and the voltage feedforward value of the hot cathode filament is calculated based on the target arc current value and target discharge time.

[0026] Among them, the hot cathode filament refers to the plasma generated by the collision of electrons excited by the electrically heated filament with hydrogen gas; the target arc current value refers to the desired discharge current setting value; the target discharge time refers to the total duration of the discharge plan set by the operator before the discharge begins; and the voltage feedforward value refers to the preset value of the filament voltage calculated based on the target arc current value and the discharge time, in order to compensate for thermal inertia in advance.

[0027] It is understood that, in the embodiments of this application, the target arc current value and target discharge time of the hot cathode filament can be obtained before controlling the hot cathode filament. The target arc current value and target discharge time represent the desired discharge conditions of the hot cathode filament. The voltage feedforward value of the hot cathode filament is calculated based on the discharge conditions to effectively compensate for the thermal inertia of the filament, so that the arc current quickly approaches the target value, thereby reducing overshoot and improving the response speed.

[0028] For example, embodiments of this application can use a Hall sensor or a current transformer to detect the arc current value of the hot cathode filament in real time, thereby accurately detecting the arc current value of the hot cathode filament and providing a reliable basis for subsequent calculations.

[0029] In some embodiments, calculating the voltage feedforward value of the hot cathode filament based on the target arc current value and the target discharge time includes: calling a pre-established feedforward control model, which includes a mapping function between the target arc current value and the steady-state voltage and a time compensation function for the hot cathode filament; inputting the target arc current value and the target discharge time into the feedforward control model; and outputting the voltage feedforward value of the hot cathode filament through the feedforward control model.

[0030] Among them, the feedforward control model refers to the model composed of the mapping function between the target arc current value and the steady-state voltage, as well as the time compensation function, which is used to calculate the voltage feedforward value; the mapping function of the steady-state voltage is used to represent the functional relationship between the steady-state operating voltage of the filament corresponding to different target arc current values; the time compensation function of the hot cathode filament is used to represent the time-varying compensation coefficient that needs to be dynamically corrected for the voltage due to thermal inertia during the discharge process.

[0031] It is understood that the embodiments of this application call a feedforward control model containing mapping functions and time compensation functions, and directly output voltage feedforward values ​​based on the target arc current value and target discharge time to compensate for filament thermal inertia in advance. The feedforward control provides most of the control quantity, thereby shortening the arc current establishment time and suppressing start-up overshoot.

[0032] In some embodiments, before invoking the pre-established feedforward control model, the method further includes: acquiring first experimental data of the hot cathode filament under different target arc current values, the first experimental data including the steady-state voltage corresponding to each target arc current value; acquiring second experimental data of the hot cathode filament under different target discharge times, the second experimental data including the measured voltage corresponding to each target discharge time; generating a mapping function between the target arc current value and the steady-state voltage based on the first experimental data; generating a time compensation function for the hot cathode filament based on the second experimental data; and establishing a feedforward control model based on the mapping function and the time compensation function.

[0033] The first experimental data refers to the filament voltage data measured when the hot cathode filament reaches a steady state under different target arc current values; the steady-state voltage refers to the filament voltage value corresponding to the arc current stabilization; the second experimental data refers to the filament voltage data measured at different target discharge time points; and the measured voltage refers to the filament voltage value actually measured at a specific discharge time.

[0034] It is understood that, in this application embodiment, by acquiring first experimental data and second experimental data, a mapping function and a time compensation function are generated, and a feedforward control model is established, so that the voltage feedforward value can accurately reflect the target arc current value and the discharge time's demand on the filament voltage, thereby improving the speed and stability of arc current control.

[0035] It should be noted that the steady-state filament voltage corresponding to the target arc current value can be determined experimentally. For example, when the target arc current value is 10 A, the steady-state filament voltage is 3 V. If this voltage is applied directly, the arc current will stabilize around 10 A after a brief fluctuation. The adjustment process is divided into transient and steady-state: the transient state is the dynamic process of the arc current transitioning from the initial state to the target value, and the steady state is the state in which the arc current finally stabilizes near the target value.

[0036] Specifically, based on the current target arc current value and the target discharge time, the feedforward mapping table is consulted and time compensation is calculated to obtain the filament voltage feedforward value. Table 1 shows the feedforward mapping table, which is obtained through experimental calibration. Multiple sets of data are shown in Table 1, including target arc current values ​​(such as 10 A, 20 A, 30 A, etc.) and their corresponding filament voltages (i.e., steady-state voltages, such as 3.2 V, 3.8 V, 4.2 V, etc.). These data are used to establish the mapping function between the target arc current value and the steady-state voltage, serving as the basic data for calculating the voltage feedforward value in the feedforward control model.

[0037] Table 1 Feedforward Mapping Table

[0038] It should be noted that when the target arc current value is not in the mapping table, the corresponding steady-state voltage is obtained by interpolating adjacent data points through the interpolation calculation unit.

[0039] Furthermore, Table 2 shows the time compensation coefficient table. The time compensation function takes into account the overshoot requirement in the initial stage of discharge, and the time compensation function decreases as the discharge time increases.

[0040] Table 2 Time Compensation Coefficient Table

[0041] Specifically, the formula for calculating the time compensation function is as follows: V_ff = f(I_target) × g(t) Where f(I_target) is the filament voltage in the mapping function; g(t) is the filament voltage coefficient; and V_ff is the voltage feedforward value.

[0042] For example, if the target arc current is 10A, Table 1 shows that the filament voltage is 3.2V. If the target discharge time is 0.3s (less than 0.5s), Table 2 shows that the filament voltage coefficient g(t) is 1.2. Then, according to the time compensation function, the voltage feedforward value is 3.2V × 1.2 = 3.84V. Furthermore, the feedforward control model is adjusted according to different discharge conditions: differences in the discharge filament type lead to different discharge conditions; after a long discharge time for the same filament, the arc current generated by the same filament voltage will be different. For example, a new filament requires 4.2V to achieve a 30A arc current; after 200 hours of use, the arc current drops to 27A at the same voltage, requiring the feedforward voltage to be increased to 4.5V.

[0043] In step S202, in response to the discharge control command of the hot cathode filament, the voltage feedback value of the hot cathode filament is calculated based on the actual arc current value and the target arc current value of the hot cathode filament.

[0044] Among them, the discharge control command refers to the control signal used to start the discharge of the hot cathode filament; the actual arc current value refers to the plasma current value collected in real time by the current sensor during the discharge process; and the voltage feedback value refers to the filament voltage adjustment amount calculated from the actual arc current value and the target arc current value.

[0045] It is understood that, in this embodiment of the application, the voltage feedback value of the hot cathode filament is calculated based on the actual arc current value and the target arc current value of the hot cathode filament in response to the discharge control command of the hot cathode filament, thereby realizing dynamic adjustment of the filament voltage and improving the stability of arc current control.

[0046] In some embodiments, calculating the voltage feedback value of the hot cathode filament based on the actual arc current value and the target arc current value includes: calculating the deviation value between the actual arc current value and the target arc current value; and calculating the voltage feedback value of the hot cathode filament based on the deviation value.

[0047] The deviation value refers to the difference between the target arc flow value and the actual arc flow value.

[0048] It is understood that the embodiments of this application calculate the deviation between the actual arc current value and the target arc current value, and calculate the voltage feedback value of the hot cathode filament based on the deviation value, thereby dynamically adjusting the filament voltage and reducing the arc current control error.

[0049] In some embodiments, calculating the voltage feedback value of the hot cathode filament based on the deviation value includes: inputting the deviation value into the controller of the hot cathode filament, and outputting the voltage feedback value of the hot cathode filament through the controller. The controller includes a differential structure, a filter, and a saturation mechanism. The differential term corresponding to the differential structure acts on the actual arc current value. The filter is used to filter the target arc current value. The saturation mechanism is used to stop the integral accumulation when the voltage feedback value reaches a preset limit value.

[0050] Among them, the controller refers to the PID controller used to calculate the voltage feedback value based on the deviation value; the differential structure refers to the differential term acting on the actual arc current value, used to avoid differential shocks caused by changes in the set value; the filter is used to perform low-pass filtering on the target arc current value before calculation, thereby smoothing the changes in the target arc current value; the saturation mechanism refers to stopping the accumulation operation of the integral term when the voltage feedback value reaches the limit value; the limit value refers to the pre-set upper and lower limits of the voltage feedback value.

[0051] It is understood that, in the embodiments of this application, the deviation value is input into the controller, and the voltage feedback value is output by the controller. The controller's differential structure differentiates the actual arc current value, the filter filters the target arc current value, and the saturation mechanism stops integral accumulation when the voltage feedback value reaches the limit value, thereby suppressing overshoot, reducing noise interference and arc current fluctuations, and avoiding integral saturation.

[0052] Specifically, this application also employs an adaptive adjustment mechanism: (1) Monitor the response characteristics of the actual arc flow and automatically adjust the parameters of the feedforward control model. Obtain a filament voltage as the feedforward parameter by querying the feedforward mapping table. Then, observe the filament voltage when the arc flow is stable after this experiment. Replace the initial filament voltage value with the steady-state voltage at the stable state and update the feedforward mapping table.

[0053] (2) The gain of the controller is dynamically adjusted according to the magnitude of the deviation. The gain is the proportional coefficient. Integral coefficient and differential coefficients The value. For example, increasing the proportional gain when there is a large deviation. Reduce proportional gain when the deviation is small. .

[0054] (3) Record the control curve of each discharge process and optimize the feedforward parameters for the next discharge.

[0055] In some embodiments, the control formula of the controller is:

[0056] Where u(t) is the output of the controller; e(t) is the deviation between the target arc flow value and the actual arc flow value; and y(t) is the actual arc flow value. This is the proportionality coefficient; The integral coefficient; is the differential coefficient.

[0057] It is understood that the embodiments of this application, through an improved adaptive controller, can adapt to parameter changes, thereby effectively suppressing overshoot and noise interference caused by sudden changes in the target value when adjusting the voltage feedback value, and avoiding filament overheating.

[0058] Specifically, in this application, the derivative term is differentiated with respect to the actual arc current value y(t) of the controlled variable, and the sign is negative. At the instant the setpoint is set, the controlled variable y(t) has not yet responded, so its derivative is 0, completely unaffected by the sudden change in the setpoint. When the arc current rises, the derivative term outputs a negative value, which is equivalent to reducing the control quantity in advance and suppressing the trend of further increase. The derivative has a "damping" effect and is based entirely on the rate of change of the real physical quantity, rather than the artificial jump of the setpoint. Therefore, compared with the control methods in related technologies, the control method of this application effectively suppresses derivative spikes, reduces arc current overshoot, and shortens the settling time.

[0059] It should be noted that in the control formula of the above controller, the negative sign indicates the negative feedback effect of the derivative term on the actual rate of change of the arc flow. Furthermore, the output weight of the above controller is lower than that of the feedforward control, with the feedforward control accounting for 70%-90% of the total control output.

[0060] In step S203, the hot cathode filament discharge is controlled according to the voltage feedforward value and the voltage feedback value.

[0061] It is understood that the embodiments of this application control the discharge of the hot cathode filament according to the voltage feedforward value and the voltage feedback value, combining the fast response of the feedforward with the precise adjustment of the feedback. For example, the arc current can be stabilized to the target value within 2-3 seconds, reducing start-up delay and overshoot.

[0062] In some embodiments, controlling the discharge of a hot cathode filament based on a voltage feedforward value and a voltage feedback value includes: calculating a voltage control value based on the voltage feedforward value and the voltage feedback value; and controlling the power supply output voltage of the hot cathode filament based on the voltage control value.

[0063] Among them, the voltage control value refers to the filament voltage control command synthesized from the voltage feedforward value and the voltage feedback value; the power supply output voltage refers to the filament heating voltage actually output by the hot cathode filament power supply.

[0064] It is understood that the embodiments of this application calculate the voltage control value based on the voltage feedforward value and the voltage feedback value, and control the power output voltage of the hot cathode filament based on the voltage control value, thereby achieving composite regulation of the filament heating voltage and improving the arc current establishment speed and steady-state accuracy.

[0065] In some embodiments, calculating a voltage control value based on a voltage feedforward value and a voltage feedback value includes: obtaining a first weighting coefficient for the voltage feedforward value and a second weighting coefficient for the voltage feedback value, wherein the first weighting coefficient is greater than the second weighting coefficient; calculating a first product of the voltage feedforward value and the first weighting coefficient; calculating a second product of the voltage feedback value and the second weighting coefficient; and calculating a voltage control value based on the first product and the second product.

[0066] Wherein, the first weighting coefficient refers to the coefficient used for weighting the voltage feedforward value; the second weighting coefficient refers to the coefficient used for weighting the voltage feedback value; the first product refers to the result of multiplying the voltage feedforward value by the first weighting coefficient; and the second product refers to the result of multiplying the voltage feedback value by the second weighting coefficient.

[0067] It is understood that, in this embodiment of the application, a first weighting coefficient of the voltage feedforward value and a second weighting coefficient of the voltage feedback value are obtained, wherein the first weighting coefficient is greater than the second weighting coefficient. A first product of the voltage feedforward value and the first weighting coefficient is calculated, and a second product of the voltage feedback value and the second weighting coefficient is calculated. The voltage control value is then calculated based on the first and second products, making the control primarily based on pre-compensation and secondarily on correction. Feedback control automatically suppresses interference, ensuring the system's anti-interference capability and accelerating arc current response while maintaining stability.

[0068] Specifically, such as Figure 3 As shown, the target arc current value jumps from 0A to 50A at 0 seconds and remains constant. The actual arc current value adjusted by PID control initially rises slowly, reaching a peak of 70A in about 2.5 seconds before gradually decreasing, and entering steady state in about 3 seconds, exhibiting significant overshoot and a long settling time. In contrast, the actual arc current value of this application rises rapidly within 0.5 seconds, approaching 50A in about 1.5 seconds, then fluctuates slightly before stabilizing, with no overshoot and a significantly faster response speed than the PID control method in related technologies.

[0069] Furthermore, Table 3 is a time-correspondence table of arc current values, showing the changes in actual arc current values ​​at different time points under the condition that the target arc current value jumps from 0A to 50A. As shown in Table 3, the actual arc current value of this application rises rapidly within 0.5 seconds and approaches the target value in about 1.5 seconds, then fluctuates slightly before stabilizing, exhibiting a faster response speed and no overshoot. In contrast, the actual arc current value of PID control rises more slowly, exhibits significant overshoot, and requires a longer time to reach steady state.

[0070] Table 3. Correspondence between arc flow values ​​and time.

[0071] Specifically, the voltage control value is calculated based on a composite control of the voltage feedforward and voltage feedback values. The composite control uses a weighted summation method, as shown in the following formula: V_control = α × V_ff + β × u_pid Where V_control is the final filament voltage control value; V_ff is the filament voltage feedforward value; u_pid is the output of the PID controller; α is the feedforward weighting coefficient; and β is the feedback weighting coefficient.

[0072] It should be noted that the sum of the feedforward weighting coefficient α and the feedback weighting coefficient β is 1, where 0.7≤α≤0.9 and 0.1≤β≤0.3. The voltage control value will be limited to a safe range, such as 2.0V-6.0V, and then converted into an analog voltage to drive the filament power supply.

[0073] Specifically, such as Figure 4 As shown, the specific process for controlling the discharge of a hot cathode filament includes the following steps: In step 401, the hot cathode filament discharge control system is initialized, and the target arc current value is set.

[0074] In step 402, the voltage feedforward value is calculated based on the target arc current value and the target discharge time.

[0075] In step 403, the actual arc flow value is acquired in real time.

[0076] In step 404, the deviation between the target arc current value and the actual arc current value is calculated, and the deviation value is input into the controller to calculate the voltage feedback value.

[0077] In step 405, composite control is performed, and the voltage control value is weighted and synthesized according to the first weighting coefficient and the second weighting coefficient.

[0078] In step 406, the output voltage control value is sent to the filament power supply.

[0079] In step 407, it is determined whether the discharge time has reached the target discharge time. If the discharge time has reached the target discharge time, proceed to step 408. If the discharge time has not reached the target discharge time, return to step 403 and continue to collect the actual arc current value in real time, repeating the subsequent steps with a period of 1ms until the discharge ends.

[0080] In step 408, if the discharge time reaches the target discharge time, the discharge ends and the system is reset, and the next round of discharge operation begins.

[0081] It should be noted that the arc current value is monitored in real time. If it exceeds a certain safety limit, the system will enter protection mode and forcibly reduce the filament voltage. When the discharge time exceeds the set time, the discharge will automatically shut off, and the filament voltage will be slowly increased at the start of the discharge to avoid current surges.

[0082] The hot cathode filament discharge control method proposed in this application obtains the target arc current value and target discharge time of the hot cathode filament, and calculates the voltage feedforward value of the hot cathode filament based on the target arc current value and target discharge time. Responding to the discharge control command of the hot cathode filament, the method calculates the voltage feedback value of the hot cathode filament based on the actual arc current value and target arc current value. This allows for control of the hot cathode filament discharge based on the voltage feedforward value and voltage feedback value. By providing control input through feedforward control, the arc current establishment time is shortened, achieving rapid filament discharge response. Furthermore, parameters are flexibly adjusted according to different discharge conditions, effectively improving adaptability. Therefore, this method solves the problems of slow plasma discharge response and poor adaptability caused by the large thermal inertia of the filament and the difficulty in adapting control methods to parameter changes under different discharge conditions during hot cathode filament discharge.

[0083] Next, the hot cathode filament discharge control system proposed according to the embodiments of this application is described with reference to the accompanying drawings.

[0084] Figure 5 This is a schematic diagram of the structure of the hot cathode filament discharge control system according to an embodiment of this application.

[0085] like Figure 5 As shown, the hot cathode filament discharge control system 10 includes: a first calculation module 100, a second calculation module 200, and a control module 300.

[0086] The first calculation module 100 is used to obtain the target arc current value and target discharge time of the hot cathode filament, and calculate the voltage feedforward value of the hot cathode filament based on the target arc current value and target discharge time; the second calculation module 200 is used to respond to the discharge control command of the hot cathode filament, and calculate the voltage feedback value of the hot cathode filament based on the actual arc current value and target arc current value of the hot cathode filament; the control module 300 is used to control the discharge of the hot cathode filament based on the voltage feedforward value and voltage feedback value.

[0087] In some embodiments, the first calculation module 100 is used to: call a pre-established feedforward control model, the feedforward control model including a mapping function between the target arc current value and the steady-state voltage and a time compensation function for the hot cathode filament; input the target arc current value and the target discharge time into the feedforward control model, and output the voltage feedforward value of the hot cathode filament through the feedforward control model.

[0088] In some embodiments, the hot cathode filament discharge control system 10 further includes a feedforward modeling module.

[0089] The feedforward modeling module is used to acquire first experimental data of the hot cathode filament under different target arc current values, including the steady-state voltage corresponding to each target arc current value; acquire second experimental data of the hot cathode filament under different target discharge times, including the measured voltage corresponding to each target discharge time; generate a mapping function between the target arc current value and the steady-state voltage based on the first experimental data; generate a time compensation function for the hot cathode filament based on the second experimental data; and establish a feedforward control model based on the mapping function and the time compensation function.

[0090] In some embodiments, the second calculation module 200 is used to: calculate the deviation between the actual arc current value and the target arc current value; and calculate the voltage feedback value of the hot cathode filament based on the deviation value.

[0091] In some embodiments, the second calculation module 200 is used to: input the deviation value into the controller of the hot cathode filament, and output the voltage feedback value of the hot cathode filament through the controller. The controller includes a differential structure, a filter and a saturation mechanism. The differential term corresponding to the differential structure acts on the actual arc current value. The filter is used to filter the target arc current value. The saturation mechanism is used to stop the integral accumulation when the voltage feedback value reaches a preset limit value.

[0092] In some embodiments, the control formula of the controller is:

[0093] Where u(t) is the output of the controller; e(t) is the deviation between the target arc flow value and the actual arc flow value; and y(t) is the actual arc flow value. This is the proportionality coefficient; The integral coefficient; is the differential coefficient.

[0094] In some embodiments, the control module 300 is configured to: calculate a voltage control value based on a voltage feedforward value and a voltage feedback value; and control the power output voltage of the hot cathode filament based on the voltage control value.

[0095] In some embodiments, the control module 300 is configured to: obtain a first weighting coefficient of the voltage feedforward value and a second weighting coefficient of the voltage feedback value, wherein the first weighting coefficient is greater than the second weighting coefficient; calculate a first product of the voltage feedforward value and the first weighting coefficient; calculate a second product of the voltage feedback value and the second weighting coefficient; and calculate a voltage control value based on the first product and the second product.

[0096] It should be noted that the foregoing explanation of the hot cathode filament discharge control method embodiment also applies to the hot cathode filament discharge control system of this embodiment, and will not be repeated here.

[0097] The hot cathode filament discharge control system proposed in this application obtains the target arc current value and target discharge time of the hot cathode filament, and calculates the voltage feedforward value of the hot cathode filament based on the target arc current value and target discharge time. Responding to the discharge control command of the hot cathode filament, it calculates the voltage feedback value of the hot cathode filament based on the actual arc current value and target arc current value. Therefore, it can control the discharge of the hot cathode filament based on the voltage feedforward value and voltage feedback value. By providing control quantity through feedforward control, the arc current establishment time is shortened, achieving rapid response of the filament discharge. Furthermore, parameters can be flexibly adjusted according to different discharge conditions, effectively improving adaptability. Thus, it solves the problems of slow plasma discharge response and poor adaptability caused by the large thermal inertia of the filament and the difficulty of adapting control methods in related technologies to parameter changes under different discharge conditions during hot cathode filament discharge.

[0098] Figure 6 A schematic diagram of the structure of a controlled nuclear fusion device provided in an embodiment of this application. The controlled nuclear fusion device may include: The memory 601, the processor 602, and the computer program stored on the memory 601 and capable of running on the processor 602.

[0099] When the processor 602 executes the program, it implements the hot cathode filament discharge control method provided in the above embodiments.

[0100] Furthermore, controlled nuclear fusion devices also include: Communication interface 603 is used for communication between memory 601 and processor 602.

[0101] The memory 601 is used to store computer programs that can run on the processor 602.

[0102] The memory 601 may include high-speed RAM (Random Access Memory) memory, and may also include non-volatile memory, such as at least one disk storage.

[0103] If the memory 601, processor 602, and communication interface 603 are implemented independently, then the communication interface 603, memory 601, and processor 602 can be interconnected via a bus to complete communication between them. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 6The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0104] Optionally, in a specific implementation, if the memory 601, processor 602, and communication interface 603 are integrated on a single chip, then the memory 601, processor 602, and communication interface 603 can communicate with each other through an internal interface.

[0105] The processor 602 may be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of this application.

[0106] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0107] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0108] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0109] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any of the following techniques known in the art, or a combination thereof: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (FPGAs), field-programmable gate arrays (FPGAs), etc.

[0110] Those skilled in the art will understand that all or part of the steps of the methods implementing the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0111] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for controlling the discharge of a hot cathode filament, characterized in that, Includes the following steps: Obtain the target arc current value and target discharge time of the hot cathode filament, and calculate the voltage feedforward value of the hot cathode filament based on the target arc current value and the target discharge time; In response to the discharge control command of the hot cathode filament, the voltage feedback value of the hot cathode filament is calculated based on the actual arc current value of the hot cathode filament and the target arc current value; The discharge of the hot cathode filament is controlled based on the voltage feedforward value and the voltage feedback value.

2. The hot cathode filament discharge control method according to claim 1, characterized in that, The step of calculating the voltage feedforward value of the hot cathode filament based on the target arc current value and the target discharge time includes: The pre-established feedforward control model is invoked, which includes the mapping function between the target arc current value and the steady-state voltage and the time compensation function of the hot cathode filament; The target arc current value and the target discharge time are input into the feedforward control model, and the voltage feedforward value of the hot cathode filament is output through the feedforward control model.

3. The hot cathode filament discharge control method according to claim 2, characterized in that, Before invoking the pre-established feedforward control model, the following is also included: Acquire first experimental data of the hot cathode filament under different target arc current values, the first experimental data including the steady-state voltage corresponding to each of the different target arc current values; Acquire second experimental data for the hot cathode filament under different target discharge times, the second experimental data including the measured voltage corresponding to each of the different target discharge times; A mapping function between the target arc current value and the steady-state voltage is generated based on the first experimental data, and a time compensation function for the hot cathode filament is generated based on the second experimental data. The feedforward control model is established based on the mapping function and the time compensation function.

4. The hot cathode filament discharge control method according to claim 1, characterized in that, The step of calculating the voltage feedback value of the hot cathode filament based on the actual arc current value and the target arc current value includes: Calculate the deviation between the actual arc flow value and the target arc flow value; The voltage feedback value of the hot cathode filament is calculated based on the deviation value.

5. The hot cathode filament discharge control method according to claim 4, characterized in that, The step of calculating the voltage feedback value of the hot cathode filament based on the deviation value includes: The deviation value is input into the controller of the hot cathode filament, and the controller outputs the voltage feedback value of the hot cathode filament. The controller includes a differential structure, a filter, and a saturation mechanism. The differential term corresponding to the differential structure acts on the actual arc current value. The filter is used to filter the target arc current value. The saturation mechanism is used to stop the integral accumulation when the voltage feedback value reaches a preset limit value.

6. The hot cathode filament discharge control method according to claim 5, characterized in that, The control formula for the controller is: Where u(t) is the output of the controller; e(t) is the deviation between the target arc flow value and the actual arc flow value; and y(t) is the actual arc flow value. This is the proportionality coefficient; The integral coefficient; is the differential coefficient.

7. The hot cathode filament discharge control method according to claim 1, characterized in that, The step of controlling the discharge of the hot cathode filament based on the voltage feedforward value and the voltage feedback value includes: Calculate the voltage control value based on the voltage feedforward value and the voltage feedback value; The power output voltage of the hot cathode filament is controlled according to the voltage control value.

8. The hot cathode filament discharge control method according to claim 7, characterized in that, The step of calculating the voltage control value based on the voltage feedforward value and the voltage feedback value includes: Obtain a first weighting coefficient for the voltage feedforward value and a second weighting coefficient for the voltage feedback value, wherein the first weighting coefficient is greater than the second weighting coefficient; Calculate the first product of the voltage feedforward value and the first weighting coefficient; Calculate the second product of the voltage feedback value and the second weighting coefficient; The voltage control value is calculated based on the first product and the second product.

9. A hot cathode filament discharge control system, characterized in that, include: The first calculation module is used to obtain the target arc current value and target discharge time of the hot cathode filament, and calculate the voltage feedforward value of the hot cathode filament based on the target arc current value and the target discharge time. The second calculation module is used to respond to the discharge control command of the hot cathode filament and calculate the voltage feedback value of the hot cathode filament based on the actual arc current value and the target arc current value of the hot cathode filament. The control module is used to control the discharge of the hot cathode filament based on the voltage feedforward value and the voltage feedback value.

10. A controlled nuclear fusion device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the hot cathode filament discharge control method according to any one of claims 1-8.

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