A method and system for controlling the heating process of a high-temperature brazing furnace

Abstract

The application relates to the technical field of industrial heat treatment, and discloses a high-temperature brazing furnace heating process control method and system. The method comprises the following steps: determining a transition temperature interval for switching from a first heating stage to a second heating stage; obtaining a first power reference value of the first heating stage, and obtaining a second power reference value of the second heating stage based on the running state of the first heating stage; monitoring a feedback temperature value of a controlled environment in a heating process in real time; when the feedback temperature value is in the transition temperature interval, determining a first weight coefficient and a second weight coefficient according to the feedback temperature value; calculating a transition target power value by using the product of the first weight coefficient and the first power reference value and the product of the second weight coefficient and the second power reference value; and generating and executing a transition control instruction based on the transition target power value to control energy output. The application effectively suppresses temperature overshoot caused by system thermal inertia, and improves energy utilization efficiency and product processing quality.

Description

Technical Field

[0001] This application relates to the field of industrial heat treatment technology, and more specifically, to a method and system for controlling the heating process of a high-temperature brazing furnace. Background Technology

[0002] In the production process of high-temperature brazing furnaces, multiple heating stages are typically set, such as a first heating stage for rapid heating and a second heating stage for precision brazing. When switching from the first to the second heating stage, the control system needs to switch from a high-power heating mode to a low-power holding or slow-heating mode. However, in existing technologies, this switching is usually based on a fixed temperature threshold; that is, when the furnace temperature reaches this threshold, the power output mode is directly switched. This abrupt switching method ignores a crucial issue: the material, size, and load of the workpieces inside the furnace are constantly changing. Different batches of workpieces have different thermal inertia. When processing workpieces with high thermal inertia (such as thick-walled parts or a full furnace load), even if the power is reduced at the switching temperature point, the enormous heat accumulated in the furnace and workpieces will still cause the temperature to continue to rise, resulting in severe temperature overshoot. Conversely, for workpieces with low thermal inertia, a sudden drop in power may lead to insufficient temperature. This sudden power change and subsequent temperature fluctuation at the stage switching point not only wastes a large amount of energy but also directly affects the stability and consistency of brazing quality, leading to defects such as incomplete welds or overheating. Therefore, how to achieve a smooth and adaptive power transition between different heating stages to cope with changing operating conditions is a technical problem that urgently needs to be solved.

[0003] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this application discloses a method and system for controlling the heating process of a high-temperature brazing furnace, aiming to solve the technical problems of temperature overshoot, unstable control, and energy waste caused by sudden power changes during heating stage switching in existing technologies.

[0005] In a first aspect, this application discloses a method for controlling the heating process of a high-temperature brazing furnace, used for power control of the high-temperature brazing furnace when switching from a first heating stage to a second heating stage. The first heating stage is the main temperature rise stage in the early phase of the high-temperature brazing furnace heating process, and the second heating stage is the subsequent core brazing process stage following the first heating stage. The method includes the following steps: Determine the transition temperature range from the first heating stage to the second heating stage. The transition temperature range is located before the target temperature point of the first heating stage. Obtain the first power reference value when the first heating stage enters the transition temperature range, and obtain the second power reference value for the second heating stage based on the operating status of the first heating stage; The feedback temperature value of the controlled environment is monitored in real time during the heating process. When the feedback temperature value is within the transition temperature range, the first weighting coefficient and the second weighting coefficient are determined based on the difference between the feedback temperature value and the start and end points of the transition temperature range. The first weighting coefficient gradually decreases as the feedback temperature value approaches the end point, while the second weighting coefficient gradually increases as the feedback temperature value approaches the end point. The transition target power value is calculated by multiplying the first weighting coefficient by the first power reference value and the second weighting coefficient by the second power reference value. Based on the transition target power value, a transition control command is generated and executed to control the energy output.

[0006] This technical solution establishes a transition temperature range between the two heating stages. Within this range, the reference power of the two stages is smoothly integrated through dynamically changing weighting coefficients, achieving a gradual power switching rather than abrupt changes. This effectively suppresses temperature overshoot caused by system thermal inertia, ensures stable temperature control, and improves energy utilization efficiency and product processing quality.

[0007] Furthermore, the step of determining the transition temperature range from the first heating stage to the second heating stage includes: Obtain the material properties, dimensional information, and loading capacity of the workpiece currently inside the furnace; Match the corresponding thermal inertia characteristic quantity based on material properties, size information, and loading capacity; The starting point of the transition temperature range is determined based on the thermal inertia characteristic quantity. The larger the thermal inertia characteristic quantity, the greater the temperature difference between the starting point and the target temperature point of the first heating stage.

[0008] This technical solution enables the setting of the transition temperature range to be adaptively adjusted according to the thermal inertia of the workpiece itself. For workpieces with high thermal inertia, the power transition stage can be entered earlier, reserving a longer response time for the system. This makes the power switching strategy more targeted and predictive, and improves the accuracy of control.

[0009] Furthermore, the step of determining the transition temperature range from the first heating stage to the second heating stage also includes: Obtain the temperature feedback delay time for the first heating stage; The width of the transition temperature range is adaptively adjusted based on the temperature feedback delay time, so that the starting point of the transition temperature range is advanced as the temperature feedback delay time increases.

[0010] This technical solution takes into account the temperature feedback delay of the control system itself, and compensates for the time lag in measurement and execution by adjusting the starting point of the transition interval in advance. This ensures the timeliness of power adjustment, avoids control decision lag caused by information delay, and further enhances the stability and accuracy of temperature control.

[0011] Furthermore, the step of obtaining the second power reference value for the second heating stage based on the operating status of the first heating stage includes: During the first heating stage, the relationship between the rate of change of heating power output and feedback temperature value is analyzed in real time to determine the thermal response coefficient under the current loading condition. Based on the thermal response coefficient and the target temperature of the second heating stage, the real-time sustaining power used to offset heat loss from the controlled environment is estimated. The real-time maintenance power is determined as the second power reference value.

[0012] This technical solution enables the online, real-time calculation of precise insulation power requirements for specific operating conditions, replacing the reliance on experience or fixed parameters. This allows the second power reference value to accurately reflect the actual thermodynamic characteristics of the current furnace load, providing a more accurate target benchmark for subsequent power smooth transition.

[0013] Furthermore, after the step of executing transition control commands to control energy output, the method further includes: Based on the power output value corresponding to the transition control command and combined with the thermal response coefficient, calculate the expected temperature rise of the controlled environment at the current moment. Obtain the actual temperature rise value at the corresponding time of the feedback temperature value, and calculate the temperature rise deviation ratio between the actual temperature rise value and the expected temperature rise value; The endpoint of the transition temperature range is dynamically shifted based on the temperature rise deviation ratio. When the temperature rise deviation ratio is greater than the preset ratio threshold, it is determined that the heat absorption efficiency of the currently loaded workpiece has shifted, and the endpoint is shifted away from the starting point to slow down the power switching slope by lengthening the span of the transition temperature range.

[0014] This technical solution introduces a real-time correction mechanism for the transition process. By comparing the difference between the expected temperature rise and the actual temperature rise, the endpoint of the transition range is dynamically adjusted, realizing online correction of the control model. This effectively addresses complex situations such as unexpected deviations in the workpiece's heat absorption efficiency, greatly improving the robustness and adaptability of the control method.

[0015] Furthermore, the step of determining the first weighting coefficient and the second weighting coefficient based on the difference between the feedback temperature value and the starting and ending points of the transition temperature range includes: Obtain the total span value of the transition temperature range. The total span value is the temperature difference between the end point and the starting point. Calculate the first difference between the endpoint and the feedback temperature value, and determine the ratio of the first difference to the total span value as the first weighting coefficient; Calculate the second difference between the feedback temperature value and the starting point, and determine the ratio of the second difference to the total span value as the second weighting coefficient.

[0016] This technical solution provides a clear, simple, and easy-to-implement linear interpolation method to calculate the weighting coefficients, ensuring that the power transition change is linearly related to the temperature position within the range, thus guaranteeing the smoothness and predictability of the power switching process.

[0017] Furthermore, the step of calculating the transition target power value using the product of the first weighting coefficient and the first power reference value, and the product of the second weighting coefficient and the second power reference value, includes: The formula for calculating the transition target power value is: U = W1 * P1 + W2 * P2; Wherein, U is the transition target power value, W1 is the first weighting coefficient, P1 is the first power reference value, W2 is the second weighting coefficient, and P2 is the second power reference value.

[0018] This technical solution clarifies the specific calculation method for the transition target power value, and integrates the power reference values ​​of the two stages in the form of a weighted sum, providing a direct mathematical model for achieving a smooth power transition.

[0019] Furthermore, the method also includes: Real-time monitoring to check whether the feedback temperature value has entered the preset phase change temperature window; When the feedback temperature value enters the phase change temperature window, the corresponding unit volume phase change heat absorption value is extracted from the preset material thermophysical response database based on the current total amount of workpiece loaded, and the first compensation power is calculated. The steps of generating and executing transition control commands to control energy output based on the transition target power value include: The first compensation power is superimposed on the transition target power value to obtain the transition target compensation power value; Based on the transition target compensation power value, a corresponding transition control command is generated and sent to the power execution unit of the high-temperature brazing furnace to execute the transition control command to compensate for the energy gap during the material phase change process.

[0020] This technical solution provides additional energy compensation for the physical phenomenon of a material undergoing a phase change and absorbing a large amount of heat at a specific temperature. It effectively avoids the problem of stagnation or sudden drop in heating rate caused by phase change heat absorption, and ensures the continuity and stability of the entire heating curve.

[0021] Further, the step of superimposing the first compensation power onto the transition target power value to obtain the transition target compensation power value includes: The actual temperature rise slope of the monitored feedback temperature value within the phase change temperature window; Calculate the deviation between the actual heating slope and the expected heating slope; The magnitude of the first compensation power is adjusted in real time according to the deviation, and the adjusted first compensation power is superimposed on the transition target power value to obtain the transition target compensation power value.

[0022] This technical solution introduces closed-loop regulation to the phase change compensation power. By monitoring the deviation of the heating slope in real time, the compensation amount is dynamically adjusted, making energy compensation more accurate. It can flexibly cope with the differences in the total heat absorption of phase change under different loading capacities, and further improves the control accuracy.

[0023] Secondly, this application also discloses a high-temperature brazing furnace heating process control system for performing the steps in any of the foregoing methods, including: The interval determination module is used to determine the transition temperature interval from the first heating stage to the second heating stage. The transition temperature interval is located before the target temperature point of the first heating stage. The reference acquisition module is used to acquire the first power reference value when the first heating stage enters the transition temperature range, and to acquire the second power reference value for the second heating stage based on the operating status of the first heating stage. The weight determination module is used to monitor the feedback temperature value of the controlled environment in real time during the heating process. When the feedback temperature value is within the transition temperature range, the first weight coefficient and the second weight coefficient are determined based on the difference between the feedback temperature value and the start and end points of the transition temperature range. The first weight coefficient gradually decreases as the feedback temperature value approaches the end point, while the second weight coefficient gradually increases as the feedback temperature value approaches the end point. The instruction calculation module is used to calculate the transition target power value by using the product of the first weighting coefficient and the first power reference value, and the product of the second weighting coefficient and the second power reference value. The power control module is used to generate and execute transition control commands to control energy output based on the transition target power value.

[0024] This technical solution provides a physical device capable of implementing the above-mentioned high-temperature brazing furnace heating process control method. It functionalizes the method steps into specific hardware or software modules, achieving the same technical effect. It solves the technical problems in the prior art, such as temperature overshoot, unstable control, and energy waste caused by power surges during heating stage switching.

[0025] In summary, the high-temperature brazing furnace heating process control method and system provided in this application innovatively sets a transition temperature range between the first and second heating stages, and uses a weighted fusion method to smoothly control the power transition within this range. This fundamentally solves the temperature overshoot problem caused by sudden power changes in traditional control methods and effectively offsets the hysteresis effect caused by the thermal inertia of the furnace body and workpiece. This allows the temperature to smoothly approach and stabilize at the target value, avoiding repeated temperature fluctuations. Therefore, it not only significantly improves the stability and accuracy of temperature control, ensuring the accurate achievement of the brazing process window, thereby improving the welding quality and consistency of the product, but also achieves the positive effects of saving energy and reducing production costs by avoiding unnecessary overheating and power oscillations. Attached Figure Description

[0026] Figure 1 This is a schematic flowchart of a high-temperature brazing furnace heating process control method provided in an embodiment of this application.

[0027] Figure 2 This is a schematic diagram of a high-temperature brazing furnace heating process control system provided in an embodiment of this application.

[0028] Labeling Explanation: 210, Interval Determination Module; 220, Reference Acquisition Module; 230, Weight Determination Module; 240, Instruction Calculation Module; 250, Power Control Module. Detailed Implementation

[0029] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0030] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0031] In the field of industrial heat treatment, especially in high-temperature brazing, the precise control of the heating process directly determines the quality of the final product. A typical high-temperature brazing process usually includes multiple heating stages. For example, there is an initial heating stage, which uses high power to quickly raise the furnace temperature to near the target temperature, i.e., the first heating stage; and a subsequent core brazing process stage, which uses lower power for precise temperature control and holding to ensure that the brazing filler metal is fully wetted and filled, i.e., the second heating stage.

[0032] During the transition from the first heating stage to the second heating stage, existing control strategies often employ a simple threshold switching method. When the temperature sensor feedback value inside the furnace reaches a preset switching point, the control system directly switches from high-power output to low-power output. This control method reveals inherent flaws when handling workpieces of different batches and characteristics. For example, when the furnace contains large-sized, high-quality, or high-density workpieces, their overall thermal inertia is significant. Even if the power is reduced at the switching temperature point, the temperature will not immediately stop rising due to the large amount of heat already stored in the furnace, tooling, and the workpiece itself. Instead, it will continue to climb due to thermal inertia, forming a significant temperature overshoot peak. This overshoot can lead to localized overheating of the workpiece, even exceeding the material's tolerance limit, causing quality problems such as overheating, deformation, or excessive brazing filler metal loss. Conversely, if the workpiece has low thermal inertia, a sudden reduction in power may result in insufficient heating power, preventing the workpiece's actual temperature from stabilizing at the temperature plateau required for brazing, thus affecting the weld strength. This sudden power change and subsequent temperature fluctuation at the stage switching point is a significant cause of unstable brazing quality and energy waste.

[0033] In this regard, firstly, referring to Figure 1 This application provides a method for controlling the heating process of a high-temperature brazing furnace, used for power control when the high-temperature brazing furnace switches from a first heating stage to a second heating stage. The first heating stage is the main temperature rise stage in the early phase of the high-temperature brazing furnace heating process, and the second heating stage is the subsequent core brazing process stage following the first heating stage. The method includes the following steps: S1. Determine the transition temperature range from the first heating stage to the second heating stage. The transition temperature range is located before the target temperature point of the first heating stage. S2. Obtain the first power reference value when the first heating stage enters the transition temperature range, and obtain the second power reference value for the second heating stage based on the operating status of the first heating stage. S3. Monitor the feedback temperature value of the controlled environment in real time during the heating process. When the feedback temperature value is within the transition temperature range, determine the first weighting coefficient and the second weighting coefficient based on the difference between the feedback temperature value and the start and end points of the transition temperature range. The first weighting coefficient gradually decreases as the feedback temperature value approaches the end point, while the second weighting coefficient gradually increases as the feedback temperature value approaches the end point. S4. Calculate the transition target power value by using the product of the first weighting coefficient and the first power reference value, and the product of the second weighting coefficient and the second power reference value. S5. Based on the transition target power value, generate and execute transition control commands to control energy output.

[0034] The first heating stage typically refers to the main temperature rise process from the start of heating to near the final brazing temperature. During this stage, the main objective of the control system is to raise the overall furnace temperature as quickly and efficiently as possible; therefore, a higher heating power is usually employed, such as 80% to 100% of the rated power.

[0035] The second heating stage is the core brazing process stage that follows the first heating stage. The goal of this stage is to precisely maintain the workpiece temperature within the brazing temperature point or a very small temperature window to complete the melting, wetting, and solidification of the filler metal. This stage typically requires a relatively small amount of power to compensate for system heat dissipation.

[0036] The transition temperature range, a core concept proposed in this application, is a temperature range defined before the target temperature point of the first heating stage. For example, if the target of the first heating stage is to raise the temperature to 1050°C, then the transition temperature range can be set from 1000°C to 1050°C. The function of this range is to act as a buffer zone for power switching, so that the power adjustment is not an instantaneous abrupt change, but a smooth and gradual process within this range.

[0037] The first power reference value refers to the heating power value used by the control system when the furnace temperature has just entered the transition temperature range. This value usually represents the high-power state at the end of the first heating stage.

[0038] The second power reference value refers to the ideal heating power value that needs to be maintained during the second heating stage. Theoretically, this value should be able to exactly offset the natural heat loss of the furnace body at the target brazing temperature, thereby achieving constant temperature control.

[0039] The core idea of ​​this method is to establish a transition temperature range, which distributes the switching process from high power to low power over a temperature range, thereby achieving a smooth power transition.

[0040] Before or during the heating process, the control system first needs to determine the transition temperature range. A basic approach is to preset this range based on process experience. For example, for a conventional brazing process, the target temperature for the first heating stage is set at 1050℃. Operators or process engineers can set a transition range with a width of 50℃ on the human-machine interface of the control system, based on the equipment characteristics. In this case, the starting point of the range is 1000℃, and the ending point is 1050℃.

[0041] Subsequently, the heating process begins, and the control system heats the furnace body at a relatively high power—this is the first heating stage. During this period, the system continuously monitors the temperature values ​​fed back by temperature sensors such as thermocouples installed inside the furnace. When the feedback temperature rises and reaches 1000°C, it enters the preset transition temperature range. At this point, the control system records the heating power at the instant of entering this range, for example, 80kW; this value is used as the first power reference value. Simultaneously, the system also requires a second power reference value for the second heating stage. In a simplified implementation, this value can be obtained from a preset process database. This database stores the theoretical holding power corresponding to different target holding temperatures. For example, if the goal of the second heating stage is to maintain 1060°C, the system can find a corresponding second power reference value of 15kW by querying the database.

[0042] As the feedback temperature rises continuously within the transition temperature range (between 1000°C and 1050°C), the control system begins to perform power smoothing calculations. The system determines two weighting coefficients—a first weighting coefficient and a second weighting coefficient—based on the relative position of the current feedback temperature within this range. The sum of these two weighting coefficients is one. When the temperature just enters the starting point (1000°C), the first weighting coefficient is one, and the second weighting coefficient is zero; when the temperature reaches the endpoint (1050°C), the first weighting coefficient becomes zero, and the second weighting coefficient becomes one. Within the range, the first weighting coefficient decreases linearly with increasing temperature, while the second weighting coefficient increases linearly.

[0043] Next, the system uses these two dynamically changing weighting coefficients to perform a weighted average of the first power reference value (80kW) and the second power reference value (15kW) to calculate a transition target power value. For example, when the temperature rises to 1025℃, the first and second weighting coefficients are both 0.5, and the calculated transition target power value is (80×0.5) plus (15×0.5), which equals 47.5kW.

[0044] Finally, based on this real-time calculated transition target power value, the control system generates corresponding control commands, such as adjusting the conduction angle of the thyristor or the duty cycle of the pulse width modulation signal, to drive the heating element to output the corresponding power. As the temperature rises from 1000℃ to 1050℃, the actual output heating power will smoothly decrease from 80kW to 15kW.

[0045] In this way, the huge impact caused by a direct power jump is avoided. For workpieces with high thermal inertia, this gradual power reduction gives the system enough time to consume the stored heat, thereby effectively suppressing temperature overshoot and allowing the temperature to reach and stabilize near the final target temperature smoothly, ensuring the brazing quality.

[0046] However, the aforementioned method of determining the transition range based on a fixed preset value has limited applicability. For workpieces of different materials, sizes, and loading capacities, their thermal inertia varies greatly, making the same transition range clearly not the optimal solution. Therefore, this application further proposes that the steps for determining the transition temperature range from the first heating stage to the second heating stage include: Obtain the material properties, dimensional information, and loading capacity of the workpiece currently inside the furnace; Match the corresponding thermal inertia characteristic quantity based on material properties, size information, and loading capacity; The starting point of the transition temperature range is determined based on the thermal inertia characteristic quantity. The larger the thermal inertia characteristic quantity, the greater the temperature difference between the starting point and the target temperature point of the first heating stage.

[0047] The key here is to allow the width of the transition zone to be adaptively adjusted according to the actual situation of the workpiece.

[0048] In practice, before each heating task begins, the operator needs to input key information about the current batch of workpieces through the control system's input interface. This information may include: the workpiece's material grade (i.e., using the material grade as a material attribute; in reality, the material's density and specific heat capacity can also be used as material attributes), such as whether it is stainless steel 304 or nickel-based high-temperature alloy GH4169; the typical external dimensions of the workpiece, such as whether it is a thin-walled tube with a wall thickness of two millimeters or a solid shaft-like part with a diameter of one hundred millimeters; and the total quantity or total weight (i.e., loading amount) of the workpiece being loaded into the furnace.

[0049] The control system has a pre-built calculation model or query database for thermal inertia characteristics. This model can convert the input material properties and dimensional information into a quantified thermal inertia characteristic.

[0050] In one embodiment, the model can be a simplified physical calculation formula. For example, based on the input material grade, the system looks up the density and specific heat capacity of the material from a built-in material library. Combined with the input workpiece size and quantity, it calculates the total mass of the workpieces inside the furnace. The thermal inertia characteristic can be defined as the product of the total mass and the specific heat capacity. The larger this value, the stronger the workpiece's ability to absorb and store heat, and the greater its thermal inertia.

[0051] In another embodiment, the model can be a predictive model built based on empirical data and machine learning algorithms. By analyzing historical production data, the model can learn the relationship between different combinations of materials, sizes, and load capacities and actual temperature control performance, thereby providing a more accurate assessment of thermal inertia characteristics for newly input workpiece information.

[0052] After determining the thermal inertia characteristic, the system can dynamically adjust the starting point of the transition temperature range accordingly. The adjustment logic is as follows: the larger the thermal inertia characteristic, the earlier the power needs to be reduced to counteract its inertial effect. Therefore, the starting point of the transition range needs to be set lower, that is, the temperature difference between the starting point and the target temperature point of the first heating stage needs to be increased.

[0053] For example, suppose the target temperature for the first heating stage is still 1050℃. When processing a batch of thin-walled stainless steel pipes, the system calculates a relatively small thermal inertia characteristic, and may set the starting point of the transition range at 1020℃, forming a 30℃ transition width. However, when processing a batch of heavy nickel-based alloy forgings, the system calculates a large thermal inertia characteristic, and will automatically advance the starting point to 980℃, forming a transition range as wide as 70℃. In this way, for heavy load and high thermal inertia conditions, the smooth power transition process can start earlier, providing the system with more buffer time, thereby more effectively suppressing temperature overshoot.

[0054] Similarly, using the second power reference value as a fixed query value in the aforementioned embodiments is also insufficient, as it cannot reflect the actual heat dissipation situation inside the furnace. Therefore, this application further proposes that the step of obtaining the second power reference value for the second heating stage based on the operating state of the first heating stage includes: During the first heating stage, the relationship between the rate of change of heating power output and feedback temperature value is analyzed in real time to determine the thermal response coefficient under the current loading condition. Based on the thermal response coefficient and the target temperature of the second heating stage, the real-time sustaining power used to offset heat loss from the controlled environment is estimated. The real-time maintenance power is determined as the second power reference value.

[0055] The solution aims to accurately calculate the actual sustaining power required under current operating conditions by identifying the thermodynamic characteristics of the system online.

[0056] Specifically, during the first heating stage, the control system not only outputs power but also functions as a data acquisition and analysis system. The system records the current heating power output and furnace feedback temperature at fixed time intervals, such as once per second. By performing differential calculations on the continuously acquired temperature data, the real-time temperature change rate, i.e., the heating rate, can be obtained.

[0057] The thermal response coefficient characterizes the rate of temperature increase per unit input power. In a simplified model, it can be defined as the ratio of the heating rate to the input power. During the heating process, the system continuously calculates this ratio and uses algorithms such as filtering or moving average to obtain a stable and representative thermal response coefficient value under the current operating conditions. This coefficient comprehensively reflects the total heat capacity of all objects in the furnace (workpieces, tooling, furnace lining) and the heat transfer efficiency between them and the heating elements.

[0058] When a second power reference value needs to be determined, the system already possesses this real-time acquired thermal response coefficient. Simultaneously, the system also knows the target temperature for the second heating stage, for example, 1060℃. The heat dissipation power of the high-temperature furnace is roughly proportional to the temperature difference between the inside and outside of the furnace, and its heat dissipation characteristics can be obtained through offline calibration or theoretical modeling. Therefore, the system can estimate the total heat dissipation power of the furnace body at the target temperature. To maintain a constant temperature, the input heating power must equal the rate of heat dissipation and cooling. At this point, the system can use the thermal response coefficient to calculate inversely how much input power is needed to produce a heating effect that precisely offsets the cooling effect, thereby stabilizing the furnace temperature. For example, if the input power measured in real time during the first heating stage is 80kW and the actual heating rate is 4℃ / s, then the thermal response coefficient is the actual heating rate divided by the input power, i.e., 4 divided by 80, resulting in a thermal response coefficient of 0.05. Assuming the target temperature for the second heating stage is 1060℃, and according to calibration, the furnace cooling rate at 1060℃ is 0.37℃ / s, then the sustaining power at this time is the cooling rate divided by the thermal response coefficient, i.e., 0.37 divided by 0.05, resulting in 7.4kW. This calculated power value is the most realistic real-time sustaining power for this particular batch of workpieces at the target temperature.

[0059] To make the calculation process of the weighting coefficients more explicit and easier to implement, this application further proposes that the steps of determining the first weighting coefficient and the second weighting coefficient based on the difference between the feedback temperature value and the starting and ending points of the transition temperature range include: Obtain the total span value of the transition temperature range. The total span value is the temperature difference between the end point and the starting point. Calculate the first difference between the endpoint and the feedback temperature value, and determine the ratio of the first difference to the total span value as the first weighting coefficient; Calculate the second difference between the feedback temperature value and the starting point, and determine the ratio of the second difference to the total span value as the second weighting coefficient.

[0060] This provides a standard linear interpolation algorithm for calculating weights.

[0061] Let's take a specific numerical example. Assume that, based on the thermal inertia of the workpiece, the system determines the transition temperature range to be 980℃ to 1050℃.

[0062] First, obtain the total span of the transition temperature range, which is 1050℃ minus 980℃, resulting in 70℃.

[0063] During the heating process, suppose that at a certain moment, the real-time monitored feedback temperature value is 1010℃.

[0064] At this point, the first difference between the endpoint and the feedback temperature value is calculated, which is 1050℃ minus 1010℃, resulting in 40℃. Then, the ratio of this first difference to the total span value is determined as the first weighting coefficient, which is 40 divided by 70, approximately equal to 0.57.

[0065] Simultaneously, the second difference between the feedback temperature value and the starting point is calculated, which is 1010℃ minus 980℃, resulting in 30℃. Then, the ratio of this second difference to the total span value is determined as the second weighting coefficient, which is 30 divided by 70, approximately equal to 0.43.

[0066] As can be seen, the sum of the first and second weighting coefficients is one. Furthermore, as the feedback temperature value moves from 980℃ to 1050℃, the difference between the feedback temperature value and the endpoint (the first difference) decreases, thus the first weighting coefficient decreases; while the difference between the feedback temperature value and the starting point (the second difference) increases, thus the second weighting coefficient increases. This perfectly meets the logical requirements for smooth power transition and requires minimal computation, making it ideal for real-time execution in industrial controllers.

[0067] After determining the calculation method for the weighting coefficients, a clear formula is also needed to calculate the final transition target power value. To this end, this application further proposes that the steps for calculating the transition target power value using the product of the first weighting coefficient and the first power reference value, and the product of the second weighting coefficient and the second power reference value, include: The formula for calculating the transition target power value is: U = W1 * P1 + W2 * P2; Wherein, U is the transition target power value, W1 is the first weighting coefficient, P1 is the first power reference value, W2 is the second weighting coefficient, and P2 is the second power reference value.

[0068] In one specific embodiment, it is assumed that the first power reference value P1 obtained when entering the transition zone is 80kW, and the second power reference value P2 calculated through online identification is 18.5kW.

[0069] When the feedback temperature is 1010℃, the calculated first weighting coefficient W1 is approximately 0.27, and the second weighting coefficient W2 is approximately 0.43.

[0070] Therefore, the target power value U at this moment is equal to (0.57×80) plus (0.43×18.5), and the calculated result is approximately 45.6 plus 7.955, which is 53.555kW.

[0071] The control system will then instruct the power execution unit to output 53.555kW of power.

[0072] It is foreseeable that when the temperature continues to rise to, for example, 1040℃, W1 will decrease to about 0.14 and W2 will increase to about 0.86. At this time, the transition target power value U will become (0.14×80) plus (0.86×18.5), which is about 11.2 plus 15.91, or 27.11kW.

[0073] Through continuous calculation and execution of this formula, the heating power achieves a smooth and linear decrease from 80kW to 18.5kW, with the entire process being stable and controlled.

[0074] Based on the above embodiments, in order to further improve the adaptability of the control method and the control accuracy under complex working conditions, this application also provides some preferred technical solutions.

[0075] In practical industrial control systems, there is an inherent time delay in the entire process from sensor detection of temperature changes to data transmission, controller calculation, and response from the power execution unit. The aforementioned method of adjusting the starting point of the transition range based on the workpiece's thermal inertia, while considering the characteristics of the controlled object, does not fully account for the inherent hysteresis of the control system itself. Therefore, this application further proposes that the step of determining the transition temperature range from the first heating stage to the second heating stage also includes: Obtain the temperature feedback delay time for the first heating stage; The width of the transition temperature range is adaptively adjusted based on the temperature feedback delay time, so that the starting point of the transition temperature range is advanced as the temperature feedback delay time increases.

[0076] This scheme aims to improve the predictability and timeliness of control actions by quantifying and compensating for the system's feedback delay.

[0077] Specifically, the temperature feedback delay time can be calibrated by performing a step response test during the equipment commissioning phase, or identified online by injecting a specific disturbance signal and analyzing the timing relationship between the input and output during system operation. This delay time integrates the thermal response time of the temperature sensor, the signal transmission delay, the controller's operation cycle, and the response time of the power actuator.

[0078] Having obtained this delay time, the control system can predict the control blind zone caused by the delay. For example, suppose the total feedback delay time measured by the system is five seconds, and at the end of the first heating stage, the average heating rate in the furnace is two degrees Celsius per second. This means that when the controller detects a certain temperature value, the actual temperature in the furnace may already be ten degrees Celsius higher than that value (five seconds multiplied by two degrees Celsius per second). (That is, the advance of the starting point of the transition temperature range is equal to the product of the average heating rate and the temperature feedback delay time.)

[0079] Therefore, to offset this effect, the system will make an additional adjustment based on the starting point of the transition range calculated from thermal inertia. For example, if the original starting point calculated based on the workpiece's thermal inertia was 1000℃, the system will now advance the starting point to 990℃, taking into account the 10℃ delay. In this way, the smooth power transition process starts earlier, effectively reserving a time window for the system's delayed response. This ensures that when the temperature actually reaches the point where a significant power reduction is required, the power adjustment action is already in place, thus more effectively avoiding temperature overshoot.

[0080] Furthermore, the thermal absorption characteristics of the workpiece may not remain constant within the transition range. For example, the radiative heat absorption rate of the material may change as the temperature rises, or slight variations in the furnace atmosphere may affect the convective heat transfer efficiency. These factors can cause deviations in the thermal response coefficient identified in the previous stage within the transition range, thereby affecting the control accuracy. To address this, this application proposes a dynamic correction mechanism. After executing the transition control command to control the energy output, the method further includes: Based on the power output value corresponding to the transition control command and combined with the thermal response coefficient, calculate the expected temperature rise of the controlled environment at the current moment. Obtain the actual temperature rise value at the corresponding time of the feedback temperature value, and calculate the temperature rise deviation ratio between the actual temperature rise value and the expected temperature rise value; The endpoint of the transition temperature range is dynamically shifted based on the temperature rise deviation ratio. When the temperature rise deviation ratio is greater than the preset ratio threshold, it is determined that the heat absorption efficiency of the currently loaded workpiece has shifted, and the endpoint is shifted away from the starting point to slow down the power switching slope by lengthening the span of the transition temperature range.

[0081] This scheme enables real-time fine-tuning of the control strategy by establishing a comparison model between the expected and actual values ​​within the transition range.

[0082] In practice, during each control cycle (e.g., per second) within the transition range, the system first calculates a theoretical expected temperature rise based on the current output transition target power value and the thermal response coefficient determined in the first heating stage. For example, if the current output power is 40kW and the thermal response coefficient is 0.05℃ / (s·kW), then the expected temperature rise for this control cycle (control cycle is 1 second) is 2℃.

[0083] Meanwhile, the system compares the current and previous second's actual feedback temperature values ​​to obtain the actual temperature rise for that cycle. Let's assume the actual temperature rise is only 1.2℃.

[0084] The system then calculates the temperature rise deviation ratio between the actual temperature rise and the expected temperature rise, which is 2℃ minus 1.2℃ and then divided by 2℃, resulting in 40%.

[0085] The control system compares this deviation ratio to a preset proportional threshold (e.g., 30%). In this example, 40% is greater than 30%, indicating that the actual temperature rise is significantly slower than expected, likely because the workpiece's heat absorption efficiency has increased in this temperature range. This means that the current rate of power reduction may be too rapid.

[0086] To address this situation, the control system performs a dynamic translation operation, shifting the endpoint of the transition temperature range away from the starting point. For example, assuming the original endpoint is 1050℃ and the system's translation coefficient is 5, based on the aforementioned temperature rise deviation ratio (40%) and the preset proportional threshold (30%), the translation amount is the translation coefficient multiplied by the difference between the deviation ratio and the proportional threshold, i.e., 5 × (40% - 30%), which is calculated to be 5℃. Therefore, the new endpoint is dynamically shifted to 1055℃.

[0087] This translational action produces immediate results: because the total span of the interval is lengthened, according to the aforementioned weighting formula, the current temperature point of 1.2℃ will be closer to the starting point within the longer interval. This will cause the calculated first weighting coefficient W1 to increase and the second weighting coefficient W2 to decrease, ultimately resulting in a larger calculated transition target power value U. This achieves a dynamic slowdown of the power decrease slope, providing the system with more energy input to compensate for unexpected heat absorption, thereby ensuring that the temperature can stably follow the preset smooth trajectory, greatly enhancing the robustness of the control method.

[0088] During the heating process of metallic materials, a special physical phenomenon exists: phase transformation. Many alloys undergo solid-state phase transformations during heating; for example, steel transforms from pearlite to austenite. This process absorbs a large amount of latent heat, causing the temperature rise to stagnate or even slightly decrease when the input power remains constant. Traditional control methods cannot effectively handle this nonlinear behavior. Therefore, this application further proposes that the method also includes: Real-time monitoring to check whether the feedback temperature value has entered the preset phase change temperature window; When the feedback temperature value enters the phase change temperature window, the corresponding unit volume phase change heat absorption value is extracted from the preset material thermophysical response database, and the first compensation power is calculated. The steps of generating and executing transition control commands to control energy output based on the transition target power value include: The first compensation power is superimposed on the transition target power value to obtain the transition target compensation power value; Based on the transition target compensation power value, a corresponding transition control command is generated and sent to the power execution unit of the high-temperature brazing furnace to execute the transition control command to compensate for the energy gap during the material phase change process.

[0089] This scheme introduces a feedforward compensation channel specifically designed to address phase change endothermic reactions.

[0090] In practice, the control system incorporates a material thermophysical response database. This database stores phase transition information for common industrial materials, including the temperature window in which the phase transition occurs (e.g., for a certain carbon steel, the phase transition window is 727°C to 780°C) and the phase transition heat absorption per unit volume.

[0091] During the heating process, the system monitors and provides real-time temperature feedback. When the temperature enters the phase transition temperature window calibrated in the database, the compensation mechanism is activated. The system uses the total workpiece volume information input by the operator at the start of the task (e.g., a total volume of 300m³). 3 The corresponding unit volume phase change heat absorption value is found in the database, and the total energy required to complete the phase change of this batch of workpieces and the average power that needs to be supplemented within the expected phase change time are calculated. This power is the first compensation power.

[0092] Then, the system directly superimposes this calculated first compensation power onto the transition target power value calculated by the main control logic (i.e., the aforementioned weighted smooth transition logic) to form a new, higher transition target compensation power value.

[0093] For example, if the main logic calculates a current transition target power of 60kW, and the first compensation power calculated to compensate for phase change heat absorption is 10kW, then the power corresponding to the instruction finally issued to the power execution unit will be 70kW. This additional 10kW of power is specifically used to fill the energy gap caused by phase change heat absorption, thereby enabling the furnace temperature to continue to rise steadily and avoiding the phenomenon of temperature stagnation or large fluctuations near the phase change point.

[0094] To make phase transition compensation more accurate, and considering the potential differences between theoretical values ​​in the database and actual operating conditions, this application further proposes a step of superimposing the first compensation power onto the transition target power value to obtain the transition target compensation power value, including: The actual temperature rise slope of the monitored feedback temperature value within the phase change temperature window; Calculate the deviation between the actual heating slope and the expected heating slope; The magnitude of the first compensation power is adjusted in real time according to the deviation, and the adjusted first compensation power is superimposed on the transition target power value to obtain the transition target compensation power value.

[0095] This scheme introduces a closed-loop feedback regulation mechanism for phase change compensation. Within the phase change temperature window, the system not only applies compensation power but also sets a desired temperature rise rate. This desired rate can be a small value, such as 0.1 degrees Celsius per second, representing the expectation that the temperature will still rise slowly and controllably while compensating for energy.

[0096] The system will monitor the actual temperature rise slope within the window in real time, compare it with the expected slope, and calculate the deviation.

[0097] If the actual temperature rise slope is lower than expected (e.g., the temperature stagnates completely, and the slope is zero), it means that the current first compensation power is insufficient to completely offset the heat absorption of the phase change. In this case, a PI controller or similar regulator will increase the output value of the first compensation power based on this negative deviation.

[0098] Conversely, if the actual temperature rise rate is higher than the expected value, it means that too much compensation power has been applied, and the regulator will reduce the compensation power accordingly.

[0099] In this way, the phase change compensation power is finely adjusted in real time and dynamically, ensuring that the supplied energy just meets the needs of the phase change process. This allows the entire heating curve to remain smooth and stable when passing through the complex phase change region, laying a solid foundation for the subsequent precision temperature control stage.

[0100] Secondly, referring to Figure 2To implement the above-mentioned high-temperature brazing furnace heating process control method, this application also provides a high-temperature brazing furnace heating process control system. This system can be a hardware circuit board integrated into the central control cabinet of the high-temperature brazing furnace, or a software program running on an industrial personal computer or programmable logic controller (PLC). This system is used to execute the steps in any of the aforementioned methods, including: The interval determination module 210 is used to determine the transition temperature interval from the first heating stage to the second heating stage. The transition temperature interval is located before the target temperature point of the first heating stage. The reference acquisition module 220 is used to acquire a first power reference value when the first heating stage enters the transition temperature range, and acquire a second power reference value for the second heating stage based on the operating status of the first heating stage. The weight determination module 230 is used to monitor the feedback temperature value of the controlled environment in real time during the heating process. When the feedback temperature value is within the transition temperature range, the first weight coefficient and the second weight coefficient are determined based on the difference between the feedback temperature value and the start point and end point of the transition temperature range. The first weight coefficient gradually decreases as the feedback temperature value approaches the end point, and the second weight coefficient gradually increases as the feedback temperature value approaches the end point. The instruction calculation module 240 is used to calculate the transition target power value by using the product of the first weighting coefficient and the first power reference value, and the product of the second weighting coefficient and the second power reference value. The power control module 250 is used to generate and execute transition control commands to control energy output based on the transition target power value.

[0101] The interval determination module 210 is specifically designed to execute the logic for determining the transition temperature range. For example, it may include an interface for human-machine interaction to receive information on the workpiece material, dimensions, and loading quantity input by the operator. The module internally contains a calculation model for thermal inertia characteristics, which can calculate the characteristics based on the input information and determine the start and end points of the transition range according to a preset mapping relationship, thereby defining the entire transition temperature range.

[0102] The reference acquisition module 220's core function is to determine two reference power values ​​for smooth power transition. On one hand, it communicates with the power monitoring unit inside the furnace, capturing and storing the current high power value as the first power reference value when the temperature enters the transition range. On the other hand, it continuously receives power and temperature data during the first heating phase, executes an online identification algorithm for the thermal response coefficient, and, in conjunction with the target holding temperature, calculates a precise second power reference value.

[0103] The weight determination module 230 is a real-time computing unit. It continuously obtains the latest feedback temperature value from the temperature sensor and determines whether the value is within the transition temperature range defined by the range determination module 210. Once it enters the range, it calculates the first weight coefficient and the second weight coefficient in real time according to the aforementioned linear interpolation formula.

[0104] The instruction calculation module 240 receives two power reference values ​​from the reference acquisition module 220 and two real-time weighting coefficients from the weight determination module 230. It calculates the transition target power value that should be output at the current moment strictly according to the weighted average formula U=W1*P1+W2*P2.

[0105] The power control module 250, as the final execution output of the system, receives the transition target power value from the instruction calculation module 240. This module converts this numerical power target into specific physical control signals. For example, for a system using thyristor power regulation, it calculates the corresponding conduction angle; for a system using solid-state relay on / off control, it generates a pulse width modulation signal with a corresponding duty cycle. These control signals are ultimately sent to the power execution unit of the high-temperature brazing furnace to drive the heating element to output precise power, thereby achieving smooth transition control throughout the heating process. The above are merely embodiments of this application and are not intended to limit the scope of protection 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 protection of this application.

Claims

1. A method for controlling the heating process of a high-temperature brazing furnace, used for power control of the high-temperature brazing furnace when switching from a first heating stage to a second heating stage, wherein, The first heating stage is the main temperature rise stage in the early stage of the high-temperature brazing furnace heating process, and the second heating stage is the subsequent core brazing process stage that follows the first heating stage. The method is characterized by the following steps: Determine the transition temperature range from the first heating stage to the second heating stage, wherein the transition temperature range is located before the target temperature point of the first heating stage; Obtain a first power reference value when the first heating stage enters the transition temperature range, and obtain a second power reference value for the second heating stage based on the operating state of the first heating stage; The feedback temperature value of the controlled environment is monitored in real time during the heating process. When the feedback temperature value is within the transition temperature range, a first weighting coefficient and a second weighting coefficient are determined based on the difference between the feedback temperature value and the start and end points of the transition temperature range. The first weighting coefficient gradually decreases as the feedback temperature value approaches the end point, and the second weighting coefficient gradually increases as the feedback temperature value approaches the end point. The transition target power value is calculated by multiplying the first weighting coefficient by the first power reference value and the second weighting coefficient by the second power reference value. Based on the target power value, a transition control command is generated and executed to control the energy output.

2. The method for controlling the heating process of a high-temperature brazing furnace according to claim 1, characterized in that, The step of determining the transition temperature range from the first heating stage to the second heating stage includes: Obtain the material properties, dimensional information, and loading capacity of the workpiece currently inside the furnace; Match the corresponding thermal inertia characteristic quantity according to the material properties, size information and loading amount; The starting point of the transition temperature range is determined based on the thermal inertia characteristic quantity, wherein the larger the thermal inertia characteristic quantity, the greater the temperature difference between the starting point and the target temperature point of the first heating stage.

3. The method for controlling the heating process of a high-temperature brazing furnace according to claim 2, characterized in that, The step of determining the transition temperature range from the first heating stage to the second heating stage further includes: Obtain the temperature feedback delay time of the first heating stage; The width of the transition temperature range is adaptively adjusted based on the temperature feedback delay time, so that the starting point of the transition temperature range is advanced as the temperature feedback delay time increases.

4. The method for controlling the heating process of a high-temperature brazing furnace according to claim 1, characterized in that, The step of obtaining the second power reference value for the second heating stage based on the operating state of the first heating stage includes: During the first heating stage, the relationship between the heating power output and the rate of change of the feedback temperature value is analyzed in real time to determine the thermal response coefficient under the current loading state. Based on the thermal response coefficient and the target temperature of the second heating stage, the real-time maintenance power used to offset the heat loss of the controlled environment is estimated. The real-time maintenance power is determined as the second power reference value.

5. The method for controlling the heating process of a high-temperature brazing furnace according to claim 4, characterized in that, After the step of executing the transition control command to control the energy output, the method further includes: Based on the power output value corresponding to the transition control command and the thermal response coefficient, the expected temperature rise of the controlled environment at the current moment is calculated. Obtain the actual temperature rise value of the feedback temperature value at the corresponding time, and calculate the temperature rise deviation ratio between the actual temperature rise value and the expected temperature rise value; The endpoint of the transition temperature range is dynamically shifted based on the temperature rise deviation ratio. When the temperature rise deviation ratio is greater than a preset ratio threshold, it is determined that the heat absorption efficiency of the currently loaded workpiece has shifted, and the endpoint is shifted away from the starting point to slow down the power switching slope by lengthening the span of the transition temperature range.

6. The method for controlling the heating process of a high-temperature brazing furnace according to claim 1, characterized in that, The step of determining the first weighting coefficient and the second weighting coefficient based on the difference between the feedback temperature value and the starting and ending points of the transition temperature range includes: Obtain the total span value of the transition temperature range, where the total span value is the temperature difference between the end point and the starting point; Calculate the first difference between the endpoint and the feedback temperature value, and determine the ratio of the first difference to the total span value as the first weighting coefficient; Calculate the second difference between the feedback temperature value and the starting point, and determine the ratio of the second difference to the total span value as the second weighting coefficient.

7. The method for controlling the heating process of a high-temperature brazing furnace according to claim 1, characterized in that, The step of calculating the transition target power value by using the product of the first weighting coefficient and the first power reference value, and the product of the second weighting coefficient and the second power reference value, includes: The formula for calculating the transition target power value is: U=W1*P1+W2*P2; Wherein, U is the transition target power value, W1 is the first weighting coefficient, P1 is the first power reference value, W2 is the second weighting coefficient, and P2 is the second power reference value.

8. The method for controlling the heating process of a high-temperature brazing furnace according to claim 1, characterized in that, The method also includes: Real-time monitoring to see if the feedback temperature value enters the preset phase change temperature window; When the feedback temperature value enters the phase change temperature window, the corresponding unit volume phase change heat absorption value is extracted from the preset material thermophysical response database according to the current total amount of workpiece loaded, and the first compensation power is calculated. The step of generating and executing transition control commands to control energy output based on the transition target power value includes: The first compensation power is superimposed on the transition target power value to obtain the transition target compensation power value; Based on the transition target compensation power value, a corresponding transition control command is generated and sent to the power execution unit of the high-temperature brazing furnace to execute the transition control command to compensate for the energy gap in the material phase transformation process.

9. The method for controlling the heating process of a high-temperature brazing furnace according to claim 8, characterized in that, The step of superimposing the first compensation power onto the transition target power value to obtain the transition target compensation power value includes: Monitor the actual temperature rise slope of the feedback temperature value within the phase transition temperature window; Calculate the deviation between the actual heating slope and the expected heating slope; The magnitude of the first compensation power is adjusted in real time according to the deviation, and the adjusted first compensation power is superimposed on the transition target power value to obtain the transition target compensation power value.

10. A high-temperature brazing furnace heating process control system, used to execute the steps of the method according to any one of claims 1 to 9, characterized in that, include: An interval determination module is used to determine the transition temperature interval from the first heating stage to the second heating stage, wherein the transition temperature interval is located before the target temperature point of the first heating stage. The reference acquisition module is used to acquire a first power reference value when the first heating stage enters the transition temperature range, and to acquire a second power reference value for the second heating stage based on the operating state of the first heating stage. The weight determination module is used to monitor the feedback temperature value of the controlled environment in real time during the heating process. When the feedback temperature value is within the transition temperature range, a first weight coefficient and a second weight coefficient are determined based on the difference between the feedback temperature value and the start and end points of the transition temperature range. The first weight coefficient gradually decreases as the feedback temperature value approaches the end point, and the second weight coefficient gradually increases as the feedback temperature value approaches the end point. The instruction calculation module is used to calculate the transition target power value by using the product of the first weighting coefficient and the first power reference value, and the product of the second weighting coefficient and the second power reference value; the power control module is used to generate and execute transition control instructions to control energy output based on the transition target power value.

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