Microwave generator and power output adjusting method and device

Abstract

The invention belongs to the technical field of microwave source equipment, and provides a microwave generator and a power output adjusting method and device, and the method comprises the steps: obtaining target output power, determining a power interval according to the target output power, and determining a corresponding control strategy according to the power interval. The control strategy includes executing several adjustment cycles. The nth regulation period comprises the following steps: executing at least one of a filament current control strategy and a magnetic field current control strategy; executing a power control strategy; the real-time output power of the microwave generator is collected, if the deviation value of the real-time output power and the target output power is within a first set range and lasts for a first time length, all the n control periods are completed, the process is ended, and the next period is not entered any more; otherwise, entering the (n + 1) th period, n being greater than or equal to 1. The optimal adjustment algorithm is selected according to the target output power, and a better power output adjustment effect is achieved.

Description

Technical Field

[0001] This application belongs to the field of microwave source equipment technology, and specifically relates to microwave generators and power output adjustment methods and devices. Background Technology

[0002] Microwave generators are widely used in industrial heating, semiconductor material preparation, medical equipment, and radar systems. Inside a microwave generator, the magnetron is the key component for microwave output. However, in industrial microwave applications, the power control of the magnetron in microwave generators still has several significant shortcomings, mainly in the following aspects:

[0003] First, there's the issue of simplistic filament control. If the filament current is too low, the cathode temperature will be insufficient, leading to a decrease in electron emission energy and a sudden drop in power. In severe cases, this can cause arcing, frequency fluctuations, and other problems, shortening the magnetron's lifespan and potentially damaging the device. Conversely, if the filament current is too high, the cathode temperature will be too high, causing excessive electron emission and resulting in power decay during long-term operation, shortening the lifespan by nearly half.

[0004] Secondly, there are limitations imposed by the solidification of the magnetic field. Ordinary magnetrons use a permanent magnet design, and the magnetic field strength cannot be adjusted; although industrial magnetrons use electromagnets, they lack a coordinated control strategy with the emission characteristics of the filament, which can easily lead to instability of the electron cloud (such as the misalignment of the convergence and divergence in a spoke-like distribution).

[0005] In addition, there is an inherent contradiction between lifespan and power: overheating of the filament will accelerate cathode aging, while an excessively strong magnetic field may cause electron backfire and lead to flameout. These problems restrict the stable operation of the magnetron.

[0006] Therefore, there is a need to provide a microwave generator and a power output regulation method and apparatus to at least partially solve the above problems. Summary of the Invention

[0007] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This summary section is not intended to limit the key and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0008] To at least partially solve the above problems, the first aspect of this application provides a method for regulating the power output of a microwave generator, comprising the following steps:

[0009] Obtain the target output power and determine the power range based on the target output power, so as to determine the corresponding control strategy based on the power range;

[0010] The control strategy includes: executing several adjustment cycles, wherein the nth adjustment cycle includes the following steps:

[0011] Execute at least one of the filament current control strategy and the magnetic field current control strategy;

[0012] Implement power control strategies;

[0013] The real-time output power of the microwave generator is collected. If the deviation between the real-time output power and the target output power is within a first set range and lasts for a first time length, then all n control cycles are completed, the process ends, and the next cycle is not entered; otherwise, the (n+1)th cycle is entered, where n≥1.

[0014] Optionally, the implementation of the filament current control strategy includes the following steps:

[0015] By comparing the real-time value of the filament current of the magnetron with the reference value of the filament current, the first control command is output based on the comparison result to adjust the filament current of the magnetron, thus forming a closed-loop control of the filament current.

[0016] The reference value of the filament current satisfies:

[0017] ;

[0018] In the formula, Indicates a reference value for the filament current; This represents the reference value of the magnetic field current in the previous cycle; K3 is the target output power, K3 is the correction factor constant; a is the filament current index; b is the magnetic field strength index; K is the magnetron parameter, which is a constant.

[0019] Optionally, the implementation of the magnetic field current control strategy includes the following steps:

[0020] By comparing the real-time value of the magnetic field current of the magnetron with the reference value of the magnetic field current, a second control command is output based on the comparison result to adjust the magnetic field current of the magnetron, thus forming a closed-loop control of the magnetic field current.

[0021] The reference value of the magnetic field current satisfies:

[0022] ;

[0023] In the formula, Indicates the reference value of the magnetic field current; This indicates the reference value of the filament current in the previous cycle; K is the target output power; K3 is the correction factor constant; a is the filament current index; b is the magnetic field strength index; K is the magnetron parameter, which is a constant.

[0024] Optionally, the power control strategy includes the following steps:

[0025] By comparing the real-time output power of the microwave generator with the target output power, corrections to the filament current and magnetic field current are output based on the comparison results.

[0026] The correction values ​​for the filament current and the magnetic field current are input into the next cycle.

[0027] Optionally, if the deviation between the real-time output power and the target output power is within a second set range and lasts for a second time length, the current control strategy is terminated, and a control strategy corresponding to the adjacent power range is executed.

[0028] Optionally, determining a power range based on the target output power, and then determining a corresponding control strategy based on the power range, includes the following steps:

[0029] The rated output power range of the microwave generator is divided into at least two power ranges, including a high power range and a low power range.

[0030] The target output power is compared with the output power range of each of the power intervals to determine the power interval;

[0031] The control parameter retrieval instruction is executed according to the power range to generate a control strategy corresponding to each power range;

[0032] The control parameters include the correction factor constant K3, filament current index a, magnetic field strength index b, magnetron parameter K, initial magnetic field current reference value, initial filament current reference value, PID parameters, and decoupling compensation coefficient.

[0033] Optionally, the power range includes a low-power segment, and the control strategy corresponding to the low-power segment includes: setting the magnetic field current to 37% to 42% of the rated magnetic field current, and executing the corresponding filament current control strategy and power control strategy; and / or

[0034] The power range includes a high-power segment, and the control strategy corresponding to the high-power segment includes: setting the value of the filament current to be less than 20% of the rated filament current, and executing the corresponding magnetic field current control strategy and power control strategy.

[0035] Optionally, the power range includes at least one medium power segment, and the control strategy corresponding to the medium power segment includes: executing the corresponding filament current control strategy, magnetic field current control strategy, and power control strategy.

[0036] A second aspect of this application also provides a power output regulation device for a microwave generator, the device including a processor for performing the method according to the first aspect of this application.

[0037] A third aspect of this application also provides a microwave generator, which includes the apparatus described in the second aspect of this application.

[0038] The method in this application selects a corresponding and optimized adjustment algorithm based on the different target output power, and achieves better power output regulation through the coordinated adjustment of current and power. When applied to microwave generators, the adjustment method can integrate the key influencing factors affecting the electron emission density of the magnetron under different power output states, and realize the organic integration of power control strategy, filament current control strategy, and magnetic field current control strategy, thereby improving the stability of the power output of the microwave generator.

[0039] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures pointed out in the description and the accompanying drawings. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A schematic flowchart of the power output adjustment method for the microwave generator of this application is shown; and

[0042] Figure 2 A flowchart illustrating a preferred embodiment of the power output adjustment method for a microwave generator according to this application is shown. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application all comply with relevant laws and regulations. In the embodiments of this application, certain existing industry solutions such as software, components, and models may be mentioned. These should be considered exemplary, intended only to illustrate the feasibility of implementing the technical solution of this application, and do not imply that the applicant has already used or necessarily used such solutions.

[0045] like Figure 1 As shown, a method for adjusting the power output of a microwave generator according to an embodiment of this application includes the following steps:

[0046] Obtain the target output power, and determine the power range based on the target output power;

[0047] Determine the corresponding control strategy based on the power range;

[0048] The control strategy includes: executing several adjustment cycles, wherein the nth adjustment cycle includes the following steps: executing at least one of the filament current control strategy and the magnetic field current control strategy; executing the power control strategy;

[0049] The real-time output power of the microwave generator is collected. If the deviation between the real-time output power and the target output power is within a first set range and lasts for a first time length, then all n control cycles are completed, the process ends, and the next cycle is not entered; otherwise, the (n+1)th cycle is entered, where n≥1.

[0050] For example, after one cycle ends, it is necessary to determine whether the deviation between the real-time output power and the target output power is within a predetermined range (for example, the predetermined range can be set to 3%Pn, where Pn is the rated power). If this condition is met, it indicates that the entire adjustment process is complete. Otherwise, the next adjustment cycle must be started.

[0051] Each power range / segment has a corresponding control strategy. In this application, the control strategy for each power range specifically includes: executing at least one of a filament current control strategy and a magnetic field current control strategy; and executing a power control strategy. This achieves synergy between current control (reflecting the high-voltage electric field and strong magnetic field) and power control. It enables the selection of different control methods to adjust the target output power when it falls within different power ranges, thereby improving the lifespan of the magnetron through optimized adjustment algorithms.

[0052] It is understood that the power range is a power segment designed for the adjustable range of the rated power of the microwave generator. The state of the magnetron varies under different output powers. This application optimizes the control of the microwave generator by dividing it into different power ranges (i.e., power segments in the following text) and using corresponding control strategies for different power ranges.

[0053] Specifically, the filament current control strategy described in this application embodiment is a closed-loop control of the filament current based on a PI regulation algorithm or a PID regulation algorithm. It includes the following steps:

[0054] A reference value for the filament current is obtained, and the real-time value of the magnetron's filament current is compared with the reference value. Based on the comparison result, a first control command is output to adjust the filament current of the magnetron, forming a closed-loop control of the filament current. As is known to those skilled in the art, the magnetron is a core component in a microwave generator. Under the combined action of a high-voltage electric field and a strong magnetic field, the magnetron generates microwave output through internal electronic resonance.

[0055] In this embodiment, the reference value of the filament current is calculated using the following formula:

[0056] ;

[0057] In the formula, Indicates a reference value for the filament current; This represents the reference value of the magnetic field current in the previous cycle; K3 is the target output power, K3 is the correction factor constant; a is the filament current index; b is the magnetic field strength index; K is the magnetron parameter, which is a constant.

[0058] Specifically, the magnetic field current control strategy described in this application embodiment is a closed-loop control of the magnetic field current based on a PI regulation algorithm or a PID regulation algorithm. It includes the following steps:

[0059] The reference value of the magnetic field current is obtained, and the real-time value of the magnetic field current of the magnetron is compared with the reference value. Based on the comparison result, a second control command is output to adjust the magnetic field current of the magnetron, thus forming a closed-loop control of the magnetic field current.

[0060] In this embodiment, the reference value of the magnetic field current is calculated using the following formula:

[0061] ;

[0062] In the formula, Indicates the reference value of the magnetic field current; This indicates the reference value of the filament current in the previous cycle; K is the target output power; K3 is the correction factor constant; a is the filament current index; b is the magnetic field strength index; K is the magnetron parameter, which is a constant.

[0063] Specifically, the power control strategy described in this application embodiment is also a closed-loop power output control based on a PI or PID regulation algorithm. It includes the following steps:

[0064] By comparing the real-time output power of the microwave generator with the target output power, corrections are made to the filament current and magnetic field current based on the comparison results. These corrections are then input to the next cycle. Through current closed-loop regulation (filament current closed-loop regulation and magnetic field current closed-loop regulation) and power closed-loop regulation, rapid adjustment of the microwave generator's output power is achieved.

[0065] For example, determining a power range based on the target output power, and then determining a corresponding control strategy based on the power range, includes the following steps:

[0066] S110: Divide the rated output power range of the microwave generator into at least two power ranges, including a high power range and a low power range.

[0067] The number of power ranges is an integer greater than 1. Based on the rated output range of the microwave generator, the power output range of the microwave generator is divided. It should be noted that the range (upper and lower limits) of each power range is clearly defined, and no two power ranges overlap; adjacent power ranges are continuous.

[0068] It is understandable that different numbers of power ranges can be designed for different microwave generators. For example, three power ranges can be set: a low-power range, a medium-power range, and a high-power range. The number of power ranges can also be two (e.g., divided only into a high-power range and a low-power range). The number of power ranges can also be more than three (e.g., in addition to the high-power and low-power ranges, at least two medium-power ranges are set).

[0069] S120: The target output power is compared with the output power range of each of the power intervals to determine the power interval.

[0070] Specifically, if the target output power value falls within a certain power range, it is considered to belong to that power range. (Reference) Figure 2 In one embodiment of this application, when the target output power is greater than 0 and less than or equal to 30% of the rated power, it belongs to the low power range; when the target output power is greater than 30% and less than or equal to 70% of the rated power, it belongs to the medium power range; and when the target output power is greater than 70% and less than or equal to 100% of the rated power, it belongs to the high power range.

[0071] S130: Execute the control parameter retrieval instruction according to the power range to generate a control strategy corresponding to each power range.

[0072] The control parameters include the correction factor constant K3, filament current index a, magnetic field strength index b, magnetron parameter K, initial magnetic field current reference value, initial filament current reference value, PID parameters, and decoupling compensation coefficient.

[0073] In the embodiments of this application, the control strategy corresponding to the low-power segment can be: setting the magnetic field current to a fixed value, for example, it can be set to 37% to 42% of the rated magnetic field current; and executing the corresponding filament current control strategy and power control strategy. The control strategy corresponding to the low-power segment can also be: executing the corresponding filament current control strategy, magnetic field current control strategy, and power control strategy.

[0074] The control strategies corresponding to the medium power range can be: executing the corresponding filament current control strategy, magnetic field current control strategy, and power control strategy.

[0075] The control strategy for the high-power range can be: setting the filament current to a fixed value, for example, less than 20% of the rated filament current, and then implementing the corresponding magnetic field current control strategy and power control strategy. Alternatively, the control strategy for the high-power range can be: implementing the corresponding filament current control strategy, magnetic field current control strategy, and power control strategy.

[0076] Furthermore, if the deviation between the real-time output power and the target output power is within a second set range and lasts for a second time length, the current control strategy ends and the control strategy corresponding to the adjacent power range is executed.

[0077] Specifically, during testing of the aforementioned power output regulation method, it was found that when the target output power value is near the boundary between two power ranges, it is possible that both control strategies corresponding to the two adjacent power ranges could achieve the target output power regulation; furthermore, using the control strategy corresponding to the adjacent range might achieve closed-loop control of the output power more quickly. To address this unexpected situation, the optimization steps described above were designed. If, after a period of adjustment, the real-time output power continues to fluctuate and cannot stabilize within the target output power range, the current control strategy is terminated, and the system directly switches to the regulation algorithm for the adjacent power range for power regulation.

[0078] In one embodiment, when the target output power value is just near the boundary point between two power ranges (nearby can be ±5%Pn, where Pn is the rated output power of the microwave generator), if after a predetermined time (e.g., 200ms), it is determined that the control strategy corresponding to the power range in which the target output power is located cannot achieve the output adjustment of the target output power, the current adjustment process ends, and at the same time, the control strategy corresponding to the adjacent power range is switched to adjust the power output until the adjustment is completed.

[0079] A second aspect of this application also provides a power output regulation device for a microwave generator, the device including a processor for performing the method according to the first aspect of this application.

[0080] A third aspect of this application also provides a microwave generator, including the aforementioned power output adjustment device.

[0081] The microwave generator also includes a magnetron and a microwave power supply. The microwave power supply powers the entire microwave generator. The magnetron is the device that generates electrons, and the filament is part of the magnetron's body. The electromagnet is the device that generates a magnetic field and is usually attached to the outside of the magnetron's body. By controlling the filament current input to the magnetron and the magnetic field current input to the electromagnet, the electron emission of the magnetron is controlled. In this embodiment, the magnetron is understood as a whole including the body and the electromagnet. The target output power is understood as the target value of the microwave generator's output power, which is also the output power of the magnetron.

[0082] The relationships between filament current and electron emission density, magnetic field strength and magnetic field current, and magnetron output power and electron emission density and magnetic field current are shown below:

[0083] 1) Relationship between electron emission density and filament current

[0084] The filament temperature T and the current satisfy Joule's law:

[0085] (1)

[0086] In the formula, K1 is the heat-to-work conversion coefficient (taken as 0.85 to 0.92), R f I is the filament resistance (0.023 to 0.15 Ω at 25℃), t is the filament energizing time (s), K2 is the heat dissipation coefficient (0.02 to 0.05), and T0 is the ambient temperature (℃); f This indicates the filament current (A).

[0087] The electron emission density J follows the Richardson-deciman equation:

[0088] (2)

[0089] In the formula, A is Richardson's constant (taken as 32A / (cm)). 2. K 2 ), φ is the work function (4.5 eV for tungsten filament), K b Boltzmann constant (1.380649 × 10⁻⁶) −23 J / K); T 阴极 T represents the absolute temperature of the filament (cathode), where T is the filament temperature (°C).

[0090] 2) Relationship between magnetic field strength and magnetic field current

[0091] (3)

[0092] In the formula, K3 is the correction factor constant, and μ0 is the free permeability (4π×10⁻⁶). −7 H / m), N is the total number of turns of the coil, I m Ω represents the magnetic field current, in amperes (A); L represents the coil length, in meters.

[0093] 3) Relationship between the output power of the magnetron and the electron emission density and magnetic field current

[0094] (4)

[0095] In the formula, K4 is the correction factor constant (ranging from 0.002 to 0.01), and J is the electron emission density of the magnetron, in A / m³. 2 B represents the magnetic field strength, measured in A / m; V a η is the anode voltage, in volts (V); η is the conversion efficiency (typically, the conversion efficiency of a magnetron is 0.6 to 0.9); P is the output power of the magnetron, in watts (W).

[0096] The following will be combined with the appendix Figure 2 The specific embodiments shown provide a detailed description of the power output method of this application.

[0097] Figure 2 The embodiment shown is divided into three power segments, each with different adjustment methods for the filament current and magnetic field current. This embodiment does not specifically limit these methods; exemplarily, the following is provided:

[0098] When operating at low power: the fixed magnetic field current is 37% to 42% of the rated value, for example, 38% of the rated value can be used. The corresponding filament current control strategy and power control strategy are implemented, including adjusting the filament current to dominate the power output, where the coefficients a=2.3 and b=0.6 (a is the filament current index, and b is the magnetic field strength index, which can be a fixed value calculated after multiple tests in the early stage; or a dynamic value calculated by collecting real-time data).

[0099] When in the medium power range: execute the corresponding filament current control strategy, magnetic field current control strategy and power control strategy, including coordinated adjustment of filament current and magnetic field current, where coefficients a=2.0 and b=0.9;

[0100] When in the high power range: the fixed filament current is 0 to 20% of the rated value, and the corresponding magnetic field current control strategy and power control strategy are implemented, including adjusting the magnetic field current to dominate the power output, where a=1.8 and b=1.2.

[0101] By controlling the filament current, the temperature of the magnetron cathode can be optimized, reducing the impact of temperature on the anode current and output power.

[0102] By controlling the magnetic field current, the trajectory of electrons can be precisely controlled, ensuring that they maintain a stable cycloidal motion and remain synchronized with the microwave field. This control mechanism effectively reduces the impact of two adverse conditions: first, if the magnetic field is too weak, electrons will directly reach the anode and fail to oscillate; second, if the magnetic field is too strong, electrons will return to the cathode, causing the system to shut down. This improves the efficiency of the microwave generator.

[0103] In one embodiment of this application, the filament current index *a* and the magnetic field strength index *b* can be obtained by fitting multiple sets of experimental data. The experimental steps are as follows: by adjusting different target output powers, multiple power output adjustment experiments are conducted, and the measured values ​​of parameters *a* and *b* are recorded after the system stabilizes. The least squares method is used for fitting and calculation. See Table 1 for a specific experimental fitting process.

[0104] Table 1

[0105] Serial Number Target output power (kW) <![CDATA[I f (A)]]> <![CDATA[I m (A)]]> coefficient a coefficient b 1 1.0 (Low Power) 8.5 0.78 2.29 0.62 2 2.0 (Low Power) 10.3 0.80 2.27 0.65 3 3.0 (Medium Power) 13.2 0.95 2.18 0.72 4 4.0 (medium power) 15.6 1.20 2.05 0.85 5 5.0 (High Power) 17.8 1.50 1.92 1.05 6 6.0 (High Power) 18.5 1.80 1.81 1.22

[0106] Based on the experimental data in Table 1, the least squares method was used to fit the data, yielding: a = 2.31 - 0.0052 × P * (±0.03), b=0.61+0.0058×P * (±0.03). Verification of the fitting results revealed that the errors between the calculated values ​​and the experimentally measured values ​​were all ≤±0.03, meeting the fitting accuracy requirements in the document. Furthermore, the testing process also showed that the a value was higher in the low-power segment (2.29 to 2.30), indicating that the filament current had a more significant impact on power. Therefore, in one embodiment of this application, the control strategy adopted in the low-power segment is to set the magnetic field current to a fixed value while simultaneously implementing the corresponding filament current control strategy and power control strategy. In contrast, the a value decreased and the b value increased in the high-power segment, reflecting the characteristic that the magnetic field current dominates power regulation. Therefore, in one embodiment of this application, the control strategy adopted in the high-power segment is to set the filament current to a fixed value while simultaneously implementing the corresponding magnetic field current control strategy and power control strategy.

[0107] In this application, the values ​​of the filament current index a and magnetic field strength index b, which were fitted to various power ranges through multiple experiments in the early stage, are pre-stored in the system so that they can be retrieved later through program commands.

[0108] After the filament current control strategy and / or magnetic field current control strategy are completed, a power control strategy can be implemented, including the following steps:

[0109] The real-time output power of the magnetron is collected and compared with the target output power; based on the comparison results, the correction values ​​of the filament current and magnetic field current are output; the real-time output power of the magnetron, the correction values ​​of the filament current and the correction values ​​of the magnetic field current are input into the next cycle.

[0110] It should be noted that in the above steps, since there may still be a certain deviation between the real-time output power and the target output power in this cycle, this deviation can correspond to the correction amount for the filament current and magnetic field current. This correction amount is used in the control and adjustment of the filament current and magnetic field current in the next cycle.

[0111] If the deviation between the real-time output power and the target output power of the magnetron is found to be within the set range after comparing the real-time output power with the target output power, the adjustment process ends and does not proceed to the next cycle. This embodiment does not specifically limit the set range. For example, if the deviation between the real-time output power and the target output power is ≤3%Pn (Pn is the rated power, which can also be selected as 2%Pn, 1%Pn or 0.5%Pn), it can be considered that all n cycles have been completed.

[0112] In summary, the power output regulation method of this application collects and monitors three quantities—filament current, magnetic field current, and output power—based on the characteristics of the magnetron, and simultaneously performs PID regulation on the filament current and magnetic field circuit to ensure that the final real-time output power meets the preset target output power.

[0113] Taking the first cycle of a certain experiment as an example, the process is as follows:

[0114] Set target output power: User inputs target output power (e.g., 1.8kW), the system obtains the target output power.

[0115] Interval judgment: =30%Pn (Pn is the rated power, assuming Pn=6kW), the power range is determined to be the low power range, and the control strategy is determined to be the control strategy corresponding to the low power range.

[0116] Initialization: Load magnetron parameters (K=0.476, a=2.3, b=0.6), set the initial filament current I. f0 =32A, initial magnetic field current I m0 =0.74A.

[0117] Solution output: With the fixed magnetic field current at 37% of the rated value (for example, the rated magnetic field current is 2A), adjust the filament current to dominate the power output; calculate the reference value of the magnetic field current. ≈0.8A, reference value for filament current ≈9.9A.

[0118] Closed-loop regulation:

[0119] Filament current control strategy: Compare the filament current of this cycle with the filament current reference value ( +ΔI f1 The deviation is then processed by the filament ring PID controller to output the PWM duty cycle.

[0120] Magnetic field current control strategy: Compare the deviation between the magnetic field current of this cycle and the magnetic field current reference value, and then output the PWM duty cycle through the magnetic field loop PID regulator.

[0121] Power control strategy: Calculate the deviation between the real-time (output) power and the target output power for the current cycle, and output the filament current I based on the deviation. f Correction amount I f1 The output magnetic field current I is based on the deviation. m Correction amount I m1 .

[0122] Once all cycles are completed, the control adjustment process ends. This indicates that the magnetron has entered normal operating mode and is outputting the target power. If, after a predetermined time, the real-time output power of the microwave generator (the real-time output power of the magnetron) fluctuates significantly around the set value (target output power), exceeding the allowable range, and the fluctuation shows no signs of abating (e.g., continuous oscillation, divergence, or irregular jumps), and the duration also exceeds the allowable range, it indicates that the power output adjustment has not entered a closed-loop steady state. In this case, the current adjustment process is terminated directly, and a control strategy for an adjacent power range is selected for readjustment.

[0123] When a power range has two adjacent power ranges, the control strategy corresponding to the power range that is closer to the target output power is preferred.

[0124] In some cases, during the adjustment and control of the magnetron's output power based on filament current and magnetic field current, the set target output power may change. For example, the user may change the target output power value. In this situation, the current control process is terminated, and the power output adjustment process is restarted based on the latest target output power. This ensures that the regulating device / system can respond promptly to changes in the target output power.

[0125] Microwave generators, as devices that produce microwaves, can be applied in microwave plasma equipment. Plasma cleaners utilize plasma to treat material surfaces, removing contaminants and enhancing activity. They are suitable for fields such as semiconductor microelectronics, medical, optics, and automotive, offering advantages such as high efficiency, environmental friendliness, and selectivity. They can also be applied in environmental protection; for example, microwave plasma torches can be used to treat various solid wastes (municipal solid waste, industrial and hazardous solid waste, medical and electronic hazardous waste, sewage sludge, as well as smelting slag and mining tailings, etc.). High-power industrial microwave generators can also be used in MPCVD equipment for the manufacture of semiconductor materials such as synthetic diamond, and the production of novel materials such as carbon nanotubes.

[0126] For embodiments of the power output regulation device for a microwave generator, no specific limitations are imposed on the hardware used. For example, when the rated output power of the microwave generator is 10kW:

[0127] 1) The processor's functions can be implemented based on an STM32F103 microprocessor (MCU). It establishes communication with the filament current controller and field current controller via a Universal Synchronous / Asynchronous Receiver / Transmitter (USART) to output control signals. Simultaneously, it acquires sensor group signals through a 12-bit ADC interface, with a sampling frequency set to 10kHz to ensure real-time data transmission. Except for the power sensor, all other control and data acquisition within the system block diagram are handled by the MCU.

[0128] refer to Figure 2 The system MCU receives the set target output power and reads the feedback value from the power sensor (or the output power setting value of the microwave power supply) to determine the real-time output power. Based on the target output power, it determines the power range—comparing it with the 30%Pn and 70%Pn thresholds—to determine the current range (low power segment, medium power segment, high power segment), and selects the corresponding power algorithm module. The low, medium, and high power algorithm modules, based on the characteristics of the range, retrieve relevant control parameters (such as the PID parameter adjustment instructions and decoupling compensation coefficients mentioned above) to generate control strategies for the closed-loop adaptive control module for each range.

[0129] 2) Filament current controller: It adopts a full-bridge phase-shift PWM topology. The PWM control signal (frequency 20kHz) output by the MCU is isolated by optocoupler (model TLP250) and then input to the driver chip to drive the MOSFET full-bridge circuit to realize the regulation of output voltage from 0 to 10V.

[0130] 3) The collected filament current signal is converted into a voltage signal by the Hall current sensor and fed back to the MCU to obtain the real-time filament current.

[0131] 4) A linear amplifier circuit is adopted. The MCU outputs a control signal of 0 to 3.3V through the DAC (digital-to-analog converter), which is amplified and drives the electromagnetic coil to realize the adjustment of the magnetic field current from 0 to 2A. The magnetic field voltage signal is collected by the sampling resistor, filtered and fed back to the MCU to obtain the real-time magnetic field current.

[0132] 5) The real-time output power is collected by the power sensor and fed back to the MCU to realize power measurement from 0 to 10kW.

[0133] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0134] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0135] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0136] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0137] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0138] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, like read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0139] Computer-readable media include both permanent and non-permanent, removable and non-removable media that can store information by any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0140] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0141] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for adjusting the power output of a microwave generator, characterized in that, Includes the following steps: Obtain the target output power and determine the power range based on the target output power, so as to determine the corresponding control strategy based on the power range; The control strategy includes: executing several adjustment cycles, wherein the nth adjustment cycle includes the following steps: Execute at least one of the filament current control strategy and the magnetic field current control strategy; Implement power control strategies; The real-time output power of the microwave generator is collected. If the deviation between the real-time output power and the target output power is within a first set range and lasts for a first time length, then all n control cycles are completed, the process ends, and the next cycle is not entered; otherwise, the (n+1)th cycle is entered, where n≥1.

2. The power output regulation method according to claim 1, characterized in that, The aforementioned filament current control strategy includes the following steps: By comparing the real-time value of the filament current of the magnetron with the reference value of the filament current, the first control command is output based on the comparison result to adjust the filament current of the magnetron, thus forming a closed-loop control of the filament current. The reference value of the filament current satisfies: ； In the formula, Indicates a reference value for the filament current; This represents the reference value of the magnetic field current in the previous cycle; K is the target output power; K3 is the correction factor constant; a is the filament current index; b is the magnetic field strength index; K is the magnetron parameter, which is a constant.

3. The power output regulation method according to claim 1, characterized in that, The aforementioned magnetic field current control strategy includes the following steps: By comparing the real-time value of the magnetic field current of the magnetron with the reference value of the magnetic field current, a second control command is output based on the comparison result to adjust the magnetic field current of the magnetron, thus forming a closed-loop control of the magnetic field current. The reference value of the magnetic field current satisfies: ； In the formula, Indicates the reference value of the magnetic field current; This indicates the reference value of the filament current in the previous cycle; K is the target output power; K3 is the correction factor constant; a is the filament current index; b is the magnetic field strength index; K is the magnetron parameter, which is a constant.

4. The power output regulation method according to claim 1, characterized in that, The aforementioned power control strategy includes the following steps: By comparing the real-time output power of the microwave generator with the target output power, corrections to the filament current and magnetic field current are output based on the comparison results. The correction values ​​for the filament current and the magnetic field current are input into the next cycle.

5. The power output regulation method according to any one of claims 1 to 4, characterized in that, If the deviation between the real-time output power and the target output power is within a second set range and lasts for a second time length, the current control strategy ends, and a control strategy corresponding to the adjacent high-power range is executed.

6. The power output regulation method according to claim 5, characterized in that, The process of determining a power range based on the target output power, and then determining a corresponding control strategy based on the power range, includes the following steps: The rated output power range of the microwave generator is divided into at least two power ranges, including a high power range and a low power range. The target output power is compared with the output power range of each of the power intervals to determine the power interval; The control parameter retrieval instruction is executed according to the power range to generate a control strategy corresponding to each power range; The control parameters include the correction factor constant K3, filament current index a, magnetic field strength index b, magnetron parameter K, initial magnetic field current reference value, initial filament current reference value, PID parameters, and decoupling compensation coefficient.

7. The power output regulation method according to claim 6, characterized in that, The power range includes a low-power segment, and the control strategy corresponding to the low-power segment includes: setting the magnetic field current to 37% to 42% of the rated magnetic field current, and executing the corresponding filament current control strategy and power control strategy; and / or The power range includes a high-power segment, and the control strategy corresponding to the high-power segment includes: setting the value of the filament current to be less than 20% of the rated filament current, and executing the corresponding magnetic field current control strategy and power control strategy.

8. The power output regulation method according to claim 6, characterized in that, The power range includes at least one medium power segment, and the control strategy corresponding to the medium power segment includes: executing the corresponding filament current control strategy, magnetic field current control strategy, and power control strategy.

9. A power output adjustment device for a microwave generator, characterized in that, The apparatus includes a processor for performing the method as described in any one of claims 1 to 8.

10. A microwave generator, characterized in that, The microwave generator includes the apparatus as described in claim 9.

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