A high-power DC furnace rectifier power supply control mainboard and control method thereof

Abstract

The present invention relates to the technical field of adaptive control systems, and in particular to a high-power DC furnace rectifier power supply control mainboard and a control method thereof. By deploying a high-power DC furnace rectifier power supply control system in a control mainboard, temperature data and voltage data are obtained through a data acquisition module; the PID parameters of the DC furnace passing through the initial state in the initial uncharged stage are obtained through an initial iteration module; the re-iteration time is determined through a charging update determination module; the PID parameters of the updated iteration after the DC furnace is charged are determined through a charging update iteration module; and the output voltage of the rectifier power supply is controlled by using the PID parameters through a voltage control module. The present invention adaptively updates the PID parameters through a high-power DC furnace rectifier power supply control system to adapt to different working states of the high-power DC furnace, so that the output voltage of the rectifier power supply is more stable, which is more conducive to the stable operation of the high-power DC furnace.

Description

Technical Field

[0001] The invention relates to the technical field of adaptive control systems, and in particular to a high-power DC furnace rectifier power supply control mainboard and a control method thereof. Background Art

[0002] The main control board of the high-power DC furnace rectifier power supply is mainly used to make the output voltage more stable, ensure equipment safety, improve energy efficiency, optimize performance and extend equipment life, and ensure stable operation and efficient production of the furnace. Generally, the PID control (Proportional (P)-Integral (I)-Derivative (D) Control) algorithm is used to adjust the output voltage of the rectifier in real time to adapt to load changes to maintain a stable output voltage and maintain system stability.

[0003] However, when the Ziegler-Nichols method is used to adjust the gain coefficient until the system begins to oscillate continuously and the corresponding P value is recorded as the critical gain, some output data are not available due to the delay of the switching elements, which may cause deviations in the calculation when the actual system begins to oscillate continuously. The existing method may have errors in the selection of the gain coefficient; and during each charging process of the high-power DC furnace, the load conditions and physical properties in the furnace will change, resulting in changes in the dynamic characteristics and load characteristics of the system. This change will affect the performance of the PID control system, which may not adapt to the new working conditions and is not conducive to the stable operation of the high-power DC furnace. Summary of the invention

[0004] In order to solve the technical problem that the existing PID parameters are inaccurate and affect the stable operation of the high-power DC furnace, the purpose of the present invention is to provide a high-power DC furnace rectifier power supply control mainboard and a control method thereof. The technical scheme adopted is as follows:

[0005] A high-power DC furnace rectifier power supply control mainboard, including a control mainboard body, and also including a high-power DC furnace rectifier power supply control system, which is used to control the high-power DC furnace rectifier power supply: the high-power DC furnace rectifier power supply control system includes a data acquisition module, an initial iteration module, a feed update determination module, a feed update iteration module and a voltage control module;

[0006] Data acquisition module: used to obtain temperature data and voltage data;

[0007] Initial iteration module: used to perform initial iteration on the P gain parameter according to a preset time interval; obtain the value parameter of each voltage extreme point according to the difference characteristics between the voltage extreme point and the adjacent data in the voltage data and the acquisition time of the voltage extreme point; analyze the fluctuation stability of the voltage extreme point in each initial iteration process based on the value parameter, and obtain the initial stability parameter of each initial iteration; terminate the initial iteration according to the initial stability parameter, and obtain the PID parameter of the initial state;

[0008] Feeding update determination module: used to determine the re-iteration time in the preset historical time domain neighborhood at the current moment, according to the fluctuation difference characteristics of the temperature data on both sides of the neighborhood midpoint, combined with the difference characteristics of the voltage data of the neighborhood midpoint and the adjacent data;

[0009] Feeding update iteration module: used to update and iterate the P gain parameter according to the preset time interval with the latest re-iteration moment as the starting point; obtain the desirability parameter of each voltage extreme point according to the relevant characteristics of the voltage data and temperature data in the preset time domain neighborhood of each voltage extreme point; based on the desirability parameter, analyze the fluctuation stability of the voltage extreme point in each update iteration process to obtain the updated stability parameter; terminate the update iteration according to the updated stability parameter, and determine the PID parameter of the current update iteration;

[0010] Voltage control module: used to control the output voltage of the high-power DC furnace rectifier power supply according to the PID parameters.

[0011] Furthermore, the DC furnace is controlled by the PID parameters of the initial state in an initial uncharged stage, and is controlled by the updated iterative PID parameters after charging.

[0012] Furthermore, the method for obtaining the value parameter includes:

[0013] According to the time domain interval between the collection moment of each voltage extreme value point and the first collection moment, combined with the difference characteristics between the numerical value of each voltage extreme value point and the numerical values ​​of the adjacent voltage data on both sides, the value parameter of each voltage extreme value point is obtained; the difference characteristics between the numerical value of the voltage extreme value point and the numerical values ​​of the adjacent voltage data on both sides are negatively correlated with the value parameter; the time domain interval corresponding to the voltage extreme value point is positively correlated with the value parameter.

[0014] Furthermore, the method for obtaining the initial stability parameters includes:

[0015] The value parameter of the voltage maximum point is normalized as the maximum weighted weight corresponding to the voltage maximum point; the sum of all the maximum weighted weights of any one of the initial iterations is 1; based on the maximum weighted weights, the voltage maximum point of each initial iteration is weighted and summed to obtain a maximum reference value; according to the difference characteristics between all the voltage maximum points and the maximum reference value of each initial iteration, the maximum error parameter of each initial iteration is obtained;

[0016] Obtaining a minimum error parameter of each initial iteration; the minimum error parameter is obtained in a similar process to the maximum error parameter;

[0017] An initial stable parameter of each initial iteration is obtained according to the minimum error parameter and the maximum error parameter; the minimum error parameter and the maximum error parameter are both negatively correlated with the initial stable parameter.

[0018] Furthermore, the method of terminating the initial iteration according to the initial stable parameters and obtaining the PID parameters of the initial state includes:

[0019] When the initial stability parameter is greater than or equal to a preset initial stability threshold, the initial iteration is terminated; and according to the Ziegler-Nichols method, the PID parameters of the initial state are obtained in combination with the P gain parameter when the initial iteration is terminated.

[0020] Furthermore, the method for obtaining the re-iteration time includes:

[0021] In the preset historical time domain neighborhood at the current moment, according to the violent fluctuation characteristics of the temperature data on the left side of the neighborhood midpoint, a left temperature fluctuation parameter is obtained; according to the violent fluctuation characteristics of the temperature data on the right side of the neighborhood midpoint, a right temperature fluctuation parameter is obtained; according to the left temperature fluctuation parameter and the right temperature fluctuation parameter, a temperature change parameter is obtained; the left temperature fluctuation parameter and the temperature change parameter are negatively correlated; the right temperature fluctuation parameter and the temperature change parameter are positively correlated;

[0022] According to the difference characteristics between the voltage data of the midpoint of the neighborhood and the adjacent data on the left, a left voltage difference parameter is obtained; according to the difference characteristics between the voltage data of the midpoint of the neighborhood and the adjacent data on the right, a right voltage difference parameter is obtained; according to the difference between the left voltage difference parameter and the right voltage difference parameter, a voltage change parameter is obtained;

[0023] An update requirement parameter is obtained according to the temperature change parameter and the voltage change parameter; the temperature change parameter and the voltage change parameter are both positively correlated with the update requirement parameter; when the update requirement parameter is greater than a preset update requirement threshold, it is determined that the PID parameter needs to be re-acquired, and the current moment is used as the re-iteration moment.

[0024] Furthermore, the method for obtaining the desirability parameter includes:

[0025] The negative correlation degree between the voltage data and the temperature data in a preset time domain neighborhood of each voltage extreme value point is obtained as a desirability parameter of each voltage extreme value point.

[0026] Furthermore, the method for obtaining the updated stability parameter includes:

[0027] Select the latest update iteration process in the time domain as the target iteration process; construct a Lagrange interpolation polynomial for the voltage maximum in the target iteration process to obtain the basis function corresponding to each voltage maximum; use the desirability parameter as the weighted weight, perform weighted summation on the product of all the voltage maximums in the target iteration process and the corresponding basis function to obtain the trend function of the voltage maximum;

[0028] Obtaining a trend function of a voltage minimum value; the process of obtaining the trend function of the voltage minimum value is similar to the process of obtaining the trend function of the voltage maximum value;

[0029] According to the stable characteristics of the difference between the trend function of the voltage maximum value and the trend function of the voltage minimum value, an updated stable parameter is obtained; the updated stable parameter is positively correlated with the stable characteristics of the difference between the trend functions.

[0030] Further, the method of terminating the update iteration according to the updated stable parameter and determining the PID parameter of the current update iteration includes:

[0031] When the update stability parameter is greater than or equal to a preset update stability threshold, the update iteration is terminated; and according to the Ziegler-Nichols method, the PID parameter of the current update iteration is obtained in combination with the P gain parameter when the update iteration is terminated.

[0032] The present invention also proposes a high-power DC furnace rectifier power supply control method, the control method comprising:

[0033] Get temperature data and voltage data;

[0034] Performing initial iterations on the gain parameters according to a preset time interval; obtaining value parameters of each voltage extreme point according to the difference characteristics between the voltage extreme point and the adjacent data in the voltage data and in combination with the acquisition time of the voltage extreme point; analyzing the fluctuation stability of the voltage extreme point in each initial iteration process based on the value parameters, and obtaining initial stable parameters of each initial iteration; terminating the initial iteration according to the initial stable parameters, and obtaining the PID parameters of the initial state;

[0035] In the preset historical time domain neighborhood at the current moment, the re-iteration moment is determined according to the fluctuation difference characteristics of the temperature data on both sides of the neighborhood midpoint, combined with the difference characteristics of the voltage data at the neighborhood midpoint and the adjacent data;

[0036] Taking the latest re-iteration moment as the starting point, the gain parameter is updated and iterated according to the preset time interval; according to the relevant characteristics of the voltage data and the temperature data in the preset time domain neighborhood of each voltage extreme point, the desirability parameter of each voltage extreme point is obtained; based on the desirability parameter, the fluctuation stability of the voltage extreme point in each update iteration process is analyzed to obtain the updated stability parameter; according to the updated stability parameter, the update iteration is terminated, and the PID parameter of the current update iteration is determined;

[0037] The output voltage of the high-power DC furnace rectifier power supply is controlled according to the PID parameters.

[0038] The present invention has the following beneficial effects:

[0039] The present invention firstly acquires temperature data and voltage data through a data acquisition module to provide a basis for analyzing data; further, in an initial iteration module, an initial iteration is performed on a P gain parameter; a value parameter of each voltage extreme point is acquired and based on the value parameter, the fluctuation stability of the voltage extreme point in each initial iteration process is analyzed, the initial iteration is terminated, the interference of instantaneous voltage fluctuation caused by control delay or unstable switching characteristics is reduced, and the PID parameters of the initial state are acquired to provide a basis for voltage control of the DC furnace in the initial non-feeding stage; further, in a feeding update determination module, the working state change of the DC furnace is analyzed through changes in temperature data and voltage data to determine the re-iteration time; further, in a feeding update iteration module, the P gain parameter is updated and iterated with the latest re-iteration time as the starting point; the desirability parameter of each voltage extreme point is acquired and based on the desirability parameter, the fluctuation stability of the voltage extreme point in each update iteration process is analyzed, the update iteration is terminated, the interference of noise data is reduced, the PID parameters of the current update iteration are determined, and a control basis is provided after the DC furnace is fed and the working state is changed; finally, in a voltage control module, the output voltage of a high-power DC furnace rectifier power supply is controlled according to the PID parameters. The present invention adaptively updates PID parameters through a high-power DC furnace rectifier power supply control system to adapt to different working states of the high-power DC furnace, so that the output voltage of the rectifier power supply is more stable, which is more conducive to the stable operation of the high-power DC furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 A system block diagram of a high-power DC furnace rectifier power supply control system provided by an embodiment of the present invention.

[0042] Figure 2 A flowchart of a method for obtaining initial stable parameters provided by an embodiment of the present invention.

[0043] Figure 3 A flowchart of a method for obtaining a re-iteration time provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of a high-power DC furnace rectifier power supply control mainboard and its control method proposed by the present invention, its specific implementation method, structure, features and effects, in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0045] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0046] The specific scheme of a high-power DC furnace rectifier power supply control mainboard and a control method thereof provided by the present invention is described in detail below in conjunction with the accompanying drawings.

[0047] A high-power DC furnace rectifier power supply control mainboard, including a control mainboard body; wherein the control mainboard body is equipped with a high-power DC furnace rectifier power supply control system, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor controls the high-power DC furnace rectifier power supply when executing the computer program.

[0048] See also Figure 1 , which shows a system block diagram of a high-power DC furnace rectifier power supply control system provided by an embodiment of the present invention, specifically including: a data acquisition module 101, an initial iteration module 102, a feeding update determination module 103, a feeding update iteration module 104 and a voltage control module 105.

[0049] Data acquisition module 101: used to acquire temperature data and voltage data.

[0050] Firstly, the temperature data and voltage data are obtained to provide the analytical data basis for obtaining PID parameters to control the high-power DC furnace rectifier power supply.

[0051] As an example, a voltage sensor is built into the mainboard of the high-power DC furnace rectifier power supply control to continuously monitor the actual output voltage and feed the voltage data back to the control system; a temperature sensor is installed in the furnace to accurately monitor the temperature and feed the temperature data back to the control system; the acquisition frequency of the temperature data and the voltage data are both 20Hz, and the acquisition start time is the same. In other embodiments of the present invention, the implementer can also set other acquisition frequencies.

[0052] Initial iteration module 102: used to perform initial iteration on the gain parameter according to a preset time interval; obtain the value parameter of each voltage extreme point according to the difference characteristics between the voltage extreme point and the adjacent data in the voltage data, combined with the acquisition time of the voltage extreme point; based on the value parameter, analyze the fluctuation stability of the voltage extreme point in each initial iteration process, and obtain the initial stable parameter of each initial iteration; terminate the initial iteration according to the initial stable parameter, and obtain the PID parameter of the initial state.

[0053] When the existing Ziegler-Nichols method is used to adjust the gain coefficient, the I gain and the D gain are first set to zero, and the P gain is gradually increased from zero for iteration until the system begins to oscillate continuously; in an embodiment of the present invention, the gain parameter is initially iterated according to a preset time interval.

[0054] As an example, the preset time interval is 10 seconds, and the iteration step is 0.1, that is, the time domain length of each initial iteration is 10 seconds, and the P gain parameter increases by 0.1 after each initial iteration.

[0055] In other embodiments of the present invention, implementers may also set other preset time intervals and other iteration steps.

[0056] Since the switching elements in the rectifier, such as thyristors or power MOSFETs, may have control delays or unstable switching characteristics during initial startup, resulting in instantaneous voltage fluctuations, the delays of these switching elements cause extreme points to be system error points, which are not desirable for oscillation calculations; considering that instantaneous voltage fluctuations will cause large differences between voltage data and adjacent data, and control delays or unstable switching characteristics occur in the initial startup stage, the value parameters of each voltage extreme point are obtained based on the difference characteristics between the voltage extreme point and the adjacent data in the voltage data, combined with the collection time of the voltage extreme point, to characterize the reference value of the voltage extreme point, in order to obtain accurate PID parameters and accurately control the rectifier power supply of a high-power DC furnace.

[0057] Preferably, in one embodiment of the present invention, the longer the time domain interval between the acquisition moment of the voltage extreme point and the first acquisition moment is, the less likely it is that the voltage instantaneous fluctuation is caused by control delay or unstable switching characteristics; the smaller the difference between the value of the voltage extreme point and the values ​​of the adjacent voltage data on both sides is, the less likely it is that the voltage instantaneous fluctuation is caused by control delay or unstable switching characteristics;

[0058] Based on this, according to the time domain interval between the collection time of each voltage extreme point and the first collection time, combined with the difference characteristics between the numerical value of each voltage extreme point and the numerical values ​​of the adjacent voltage data on both sides, the value parameters of each voltage extreme point are obtained; the difference characteristics between the numerical value of the voltage extreme point and the numerical values ​​of the adjacent voltage data on both sides are negatively correlated with the value parameters; the time domain interval corresponding to the voltage extreme point is positively correlated with the value parameters.

[0059] As an example, the calculation formula of the value parameter includes:

[0060] ;in, Indicates The value parameters of the voltage extreme points; represents the hyperbolic tangent function; Indicates the preset adjustment factor. In this example, ; Indicates The acquisition time of each voltage extreme point; Indicates The first acquisition moment is also the acquisition moment of the first voltage extreme point; Indicates The data value of the voltage extreme point; Indicates The data value of the data point adjacent to the left side of the voltage extreme point; Indicates The data value of the data point adjacent to the right side of the voltage extreme point; Indicates the preset divide-by-zero positive parameter. In this example, ;| | means taking the absolute value.

[0061] In the calculation formula of the value parameter, It represents the time domain interval between the acquisition time of the voltage extreme point and the first acquisition time. The larger the time interval, the smaller the possibility that the current voltage extreme point is the instantaneous voltage fluctuation caused by control delay, and the larger the value parameter. The difference between the value of the voltage extreme point and the adjacent voltage data values ​​on both sides is represented by a negative correlation mapping in the form of taking the inverse. The larger it is, the greater the difference between the value of the voltage extreme point and the adjacent voltage data values ​​on both sides, the more obvious the difference characteristics are, the more likely it is an instantaneous voltage fluctuation, the lower the reference value, and the smaller the value parameter.

[0062] It should be noted that, when the positive direction of the time domain is set to the right and the negative direction of the time domain is set to the left, the adjacent data on the right is the next data in the time series, and the adjacent data on the left is the previous data in the time series.

[0063] In other embodiments of the present invention, the implementer may set other preset adjustment coefficients and preset zero-dividing positive parameters; or the implementer may obtain the left slope and the right slope of the voltage extreme point, and replace the sum of the absolute value of the left slope and the absolute value of the right slope with It represents the difference between the value of the voltage extreme point and the adjacent voltage data values ​​on both sides; other negative correlation functions can also be used, such as Negative correlation mapping is performed, where Expressed as a natural constant An exponential function with base ; Represents the independent variable.

[0064] When the control system begins to show continuous stable oscillation, it means that the P gain parameter has reached a critical value. At this time, the PID parameters suitable for the current working state of the DC furnace can be obtained. Therefore, based on the value parameters, the fluctuation stability of the voltage extreme point of each initial iteration process is analyzed, and the initial stable parameters of each initial iteration are obtained to characterize the system stability of the initial iteration, which provides a basis for the subsequent determination of the termination of the initial iteration; then, the initial iteration is terminated according to the initial stable parameters, the PID parameters of the initial state are obtained, and the rectifier power supply of the high-power DC furnace is adjusted.

[0065] Preferably, in one embodiment of the present invention, the method for obtaining the initial stable parameters includes:

[0066] See also Figure 2 , which shows a flow chart of a method for obtaining initial stable parameters provided by an embodiment of the present invention, specifically comprising:

[0067] Step S201: normalize the value parameters of the voltage maximum point and use them as the maximum weighted weights of the corresponding voltage maximum point; the sum of all the maximum weighted weights of any initial iteration process is 1; based on the maximum weighted weights, perform weighted summation on the voltage maximum points of each initial iteration process to obtain the maximum reference value; obtain the maximum error parameters of each initial iteration based on the difference characteristics between all the voltage maximum points of each initial iteration process and the maximum reference value.

[0068] When the system oscillates stably, the voltage maximum tends to a data value, so the maximum reference value is obtained to represent the concentrated characteristics of the overall voltage maximum. By analyzing the difference characteristics between the voltage maximum and the maximum reference value, the maximum error parameter of each initial iteration is obtained, which reflects the stability of the system oscillation. Considering that the reference value of the voltage maximum is different, the value parameter of the voltage maximum point is normalized as the maximum weighted weight of the corresponding voltage maximum point. Based on the maximum weighted weight, the voltage maximum point of each initial iteration process is weighted and summed to obtain the maximum reference value. Among them, the sum of all maximum weighted weights of any initial iteration process is 1.

[0069] As an example, the calculation formula of the maximum reference value includes:

[0070] ;in, Indicates The maximum reference value of the initial iteration; Indicates The number of voltage maxima in the initial iterations; Indicates During the initial iteration The value parameter of the voltage maximum value; Indicates The sum of the value parameters of all voltage maxima during the initial iteration, Indicates During the initial iteration The maximum weight of each voltage maximum; Indicates During the initial iteration The data value of the voltage maximum value.

[0071] In the calculation formula of the maximum reference value, the value parameter is normalized by the sum of the value parameters of all voltage maxima in the initial iteration process as the maximum weighted weight, and the sum of all maximum weighted weights in an initial iteration process is 1; using the maximum weighted weight, the voltage maximum points in each initial iteration process are weighted and summed to obtain the maximum reference value, reducing the interference of voltage maximum points with low reference value, and obtaining the maximum reference value that can better represent the concentrated characteristics of the overall voltage maximum, which is convenient for further analysis of the difference characteristics between the voltage maximum and the maximum reference value.

[0072] As an example, the maximum reference value is regarded as the average value, and the average absolute deviation of all maximum values ​​in each initial iteration process is obtained, that is, the average value of the absolute value of the difference between each data and the data average value, which is used as the maximum error parameter of each initial iteration; the average absolute deviation is used to represent the difference characteristics between all voltage maximum points and the maximum reference value in each initial iteration process. The larger the average absolute deviation, the more obvious the deviation characteristics of the overall voltage maximum point from the maximum reference value, the larger the difference characteristics, the larger the maximum error parameter, and the more unstable the system voltage oscillation.

[0073] In other embodiments of the present invention, the implementer may also obtain the variance or other methods to represent the difference characteristics between all voltage maximum points and the maximum reference value in each initial iteration process, and use the variance as the maximum error parameter.

[0074] Step S202: Obtain the minimum error parameter of each initial iteration; the process of obtaining the minimum error parameter is similar to that of obtaining the maximum error parameter.

[0075] Similarly, when the system oscillates stably, the voltage minimum approaches a data value, so the minimum error parameter of each initial iteration is obtained; the process of obtaining the minimum error parameter is similar to that of obtaining the maximum error parameter.

[0076] The calculation process may be as follows: normalizing the value parameter of the voltage minimum point and using it as the minimum weighted weight of the corresponding voltage minimum point; the sum of all minimum weighted weights of any initial iteration process is 1; based on the minimum weighted weight, weighted summing is performed on the voltage minimum points of each initial iteration process to obtain the minimum reference value; according to the difference characteristics between all voltage minimum points of each initial iteration process and the minimum reference value, the minimum error parameter of each initial iteration is obtained. The specific steps have been described in step S201 and will not be repeated here.

[0077] Step S203: obtaining an initial stable parameter for each initial iteration according to the minimum error parameter and the maximum error parameter; the minimum error parameter and the maximum error parameter are both negatively correlated with the initial stable parameter.

[0078] As an example, the sum of the minimum error parameter and the maximum error parameter is calculated using the negative correlation function After negative correlation mapping, it is used as the initial stable parameter corresponding to the initial iteration; the minimum error parameter and the maximum error parameter are both non-negative numbers, so Normalization is also performed while performing negative correlation mapping.

[0079] When the P gain parameter is initially iterated to the critical value, the output voltage of the high-power DC furnace rectifier power supply control system will continue to oscillate stably, and the maximum or minimum value will approach a stable value. The smaller the minimum error parameter and the maximum error parameter, the better, and the larger the initial stability parameter, the better.

[0080] Preferably, in one embodiment of the present invention, when the initial stability parameter is greater than or equal to a preset initial stability threshold, the initial iteration is terminated; and according to the Ziegler-Nichols method, combined with the P gain parameter when the initial iteration is terminated, the PID parameters of the initial state are obtained.

[0081] As an example, the preset initial stability threshold is 0.9, and when the initial stability parameter is greater than or equal to 0.9, the initial iteration is terminated; according to the Ziegler-Nichols method, combined with the P gain parameter when the initial iteration is terminated, the PID parameters of the initial state are obtained.

[0082] It should be noted that the Ziegler-Nichols method for obtaining PID parameters is a technical means well known to those skilled in the art and will not be described in detail.

[0083] The feed update determination module 103 is used to determine the re-iteration time in the preset historical time domain neighborhood at the current moment according to the fluctuation difference characteristics of the adjacent temperature data on both sides of the neighborhood midpoint and the difference characteristics between the voltage data of the neighborhood midpoint and the adjacent data.

[0084] During each charging process of a high-power DC furnace, the load inside the furnace will change, affecting the changes in current and voltage, and affecting the response of the PID controller; and changing the dynamic characteristics of the furnace such as thermal inertia and heat conduction. This change will affect the performance of the PID control system, and the PID parameters need to be readjusted to ensure that the controller can adapt to the new working conditions. Therefore, the re-iteration time is determined first.

[0085] Considering that the working state of the DC furnace is stable before adding materials and the temperature data is stable, and the working state of the DC furnace changes after adding materials, the temperature data also changes, so there is a difference in temperature fluctuation before and after adding materials; at the same time, considering that adding materials will affect the stability of the voltage, the voltage data will oscillate, and there will be a large difference with the voltage data on both sides, so in the preset historical time domain neighborhood at the current moment, according to the fluctuation difference characteristics of the adjacent temperature data on both sides of the midpoint of the neighborhood, combined with the difference characteristics of the voltage data of the midpoint of the neighborhood and the adjacent data, the re-iteration time is determined.

[0086] Preferably, in one embodiment of the present invention, the method for obtaining the re-iteration time includes:

[0087] See also Figure 3 , which shows a flow chart of a method for obtaining a re-iteration time provided by an embodiment of the present invention, specifically comprising:

[0088] Step S301: In the preset historical time domain neighborhood at the current moment, obtain the left temperature fluctuation parameter according to the drastic fluctuation characteristics of the temperature data on the left side of the neighborhood midpoint; obtain the right temperature fluctuation parameter according to the drastic fluctuation characteristics of the temperature data on the right side of the neighborhood midpoint; obtain the temperature change parameter according to the left temperature fluctuation parameter and the right temperature fluctuation parameter.

[0089] Among them, the left temperature fluctuation parameter and the temperature change parameter are negatively correlated; the right temperature fluctuation parameter and the temperature change parameter are positively correlated.

[0090] Since it is necessary to compare the changes in temperature data and voltage data before and after the addition of materials, the analysis is performed in the historical neighborhood; in order to compare the temperature change characteristics, the preset historical time domain neighborhood is divided by the neighborhood midpoint.

[0091] Taking into account that the working state of the DC furnace is stable and the temperature data is stable before adding materials, the left temperature fluctuation parameter is obtained according to the violent fluctuation characteristics of the temperature data on the left side of the neighborhood midpoint. The smaller the temperature fluctuation on the left side, the better. Therefore, the left temperature fluctuation parameter and the temperature change parameter are negatively correlated. After adding materials, the working state of the DC furnace changes, the temperature data also changes, and the temperature fluctuation is more violent. According to the violent fluctuation characteristics of the temperature data on the right side of the neighborhood midpoint, the right temperature fluctuation parameter is obtained. The more violent the temperature fluctuation on the right side, the better. The right temperature fluctuation parameter and the temperature change parameter are positively correlated.

[0092] Compare the temperature changes on both sides of the neighborhood midpoint, obtain the temperature change parameters according to the left temperature fluctuation parameters and the right temperature fluctuation parameters, characterize the change of temperature data, evaluate the need to re-update the PID parameters from the perspective of temperature change, and provide a temperature perspective basis for determining the update demand parameters.

[0093] As an example: the preset length of the historical time domain neighborhood is 101, the number of temperature data on the left and right sides of the neighborhood midpoint is 50, and the neighborhood midpoint does not participate in the calculation of the temperature change parameter; the temperature average of the left temperature data is calculated as the left temperature mean, and the sum of the absolute values ​​of the differences between all temperature data in the left temperature data and the left temperature mean is used as the left temperature fluctuation parameter. The smaller the sum of the absolute values ​​of the differences between the left temperature data and the left temperature mean, the more concentrated the temperature data is near the temperature mean, and the smaller the violent fluctuation feature is. The violent fluctuation feature of the temperature data is expressed by the deviation feature of the temperature data relative to the temperature mean; similarly, the right temperature mean is obtained, and the right temperature fluctuation parameter is obtained; the right temperature fluctuation parameter is used as the numerator, the sum of the left temperature fluctuation parameter and the preset zero division positive parameter 0.1 is used as the denominator, and the fractional ratio is used as the temperature change parameter.

[0094] In other embodiments of the present invention, the implementer may also obtain the standard deviation of the temperature data to reflect the drastic fluctuation characteristics of the temperature data, and use the correlation function to perform positive or negative correlation mapping, such as the positive correlation function and , negative correlation function .

[0095] Step S302: Obtain a left voltage difference parameter based on the difference characteristics between the voltage data of the neighborhood midpoint and the adjacent data on the left; obtain a right voltage difference parameter based on the difference characteristics between the voltage data of the neighborhood midpoint and the adjacent data on the right; obtain a voltage change parameter based on the difference between the left voltage difference parameter and the right voltage difference parameter.

[0096] Taking into account that when the voltage oscillates, there will be a large difference between adjacent voltage data, and due to the inappropriate PID parameters, the output voltage oscillation mode is uncertain, and the difference between adjacent voltage data is also uncertain. Therefore, the left voltage difference parameter is obtained according to the difference characteristics between the voltage data of the midpoint of the neighborhood and the adjacent data on the left; the right voltage difference parameter is obtained according to the difference characteristics between the voltage data of the midpoint of the neighborhood and the adjacent data on the right; the voltage change parameter is obtained according to the difference between the left voltage difference parameter and the right voltage difference parameter.

[0097] As an example, the absolute value of the difference between the voltage data of the midpoint of the neighborhood and the adjacent data on the left is used as the left voltage difference parameter. The difference characteristics between the voltage data are reflected by the absolute value of the difference. The larger the absolute value of the difference, the more obvious the difference characteristics. Similarly, the absolute value of the difference between the voltage data of the midpoint of the neighborhood and the adjacent data on the right is used as the right voltage difference parameter. The absolute value of the difference between the left voltage difference parameter and the right voltage difference parameter is used as the voltage change parameter. The need to re-update the PID parameters is evaluated from the perspective of voltage change, providing a voltage angle basis for determining the update demand parameters.

[0098] In other embodiments of the present invention, the implementer may also use the time axis as the horizontal axis, the voltage axis as the vertical axis, and the acquisition time and voltage data values ​​as coordinates, map the voltage data of the neighborhood midpoint and the adjacent data on both sides to a two-dimensional coordinate system, calculate the Euclidean distance between the voltage data of the neighborhood midpoint and the adjacent data on the left, and the Euclidean distance between the voltage data of the neighborhood midpoint and the adjacent data on the right, and reflect the difference characteristics between the voltage data through the Euclidean distance. The larger the Euclidean distance, the greater the difference characteristics. Then, the absolute value of the difference between the two Euclidean distances corresponding to the neighborhood midpoint is used as the voltage change parameter.

[0099] Step S303: Obtain update requirement parameters according to temperature change parameters and voltage change parameters; both temperature change parameters and voltage change parameters are positively correlated with update requirement parameters; when the update requirement parameters are greater than a preset update requirement threshold, determine that the PID parameters need to be re-acquired, and use the current moment as the re-iteration moment.

[0100] After obtaining the temperature change parameters and voltage change parameters, the update demand parameters can be evaluated by combining the temperature change angle and the voltage change angle. The larger the temperature change parameter, the more obvious the fluctuation difference characteristics of the temperature data on both sides of the neighborhood midpoint. The obvious temperature change in the DC furnace is more likely to be caused by adding materials, and the more the PID parameters need to be updated; the larger the voltage change parameter, the more unstable the difference between the neighborhood midpoint and the voltage data on both sides, the more inappropriate the PID parameters, and the more the PID parameters need to be updated. Therefore, the temperature change parameter and the voltage change parameter are positively correlated with the update demand parameters.

[0101] As an example, the product of the temperature change parameter and the voltage change parameter is normalized to the maximum and minimum values ​​and used as the update demand parameter.

[0102] The larger the update demand parameter is, the more the current PID parameters need to be updated to adapt to the working state of the high-power DC furnace. Therefore, when the update demand parameter is greater than the preset update demand threshold, it is determined that the PID parameters need to be re-acquired and the current moment is used as the re-iteration moment.

[0103] As an example, the preset update requirement threshold is 0.7. When the update requirement parameter is 0.7, it is determined that the PID parameters need to be re-acquired, and the current moment is used as the re-iteration moment.

[0104] In other embodiments of the present invention, implementers may also set other preset update requirement thresholds.

[0105] Feeding update iteration module 104: used to update and iterate the P gain parameters according to the preset time interval with the latest re-iteration moment as the starting point; obtain the desirability parameters of each voltage extreme point according to the relevant characteristics of the voltage data and temperature data in the preset time domain neighborhood of each voltage extreme point; based on the desirability parameters, analyze the fluctuation stability of the voltage extreme point during each update iteration to obtain the updated stability parameters; terminate the update iteration according to the updated stability parameters, and determine the PID parameters of the current update iteration.

[0106] After the re-iteration time is determined by the feeding update determination module 103, it is necessary to take the latest re-iteration time as the starting point and update the P gain parameter according to the preset time interval to adapt to the working state of the high-power DC furnace.

[0107] In one embodiment of the present invention, the iteration mode of the update iteration is set to be consistent with the iteration mode of the initial iteration.

[0108] After adding materials, as the temperature in the DC furnace rises, due to the combined effects of the characteristics of the power MOSFET and the steady-state heat transfer characteristics of the arc, under certain conditions, as the temperature increases, the voltage will decrease instead, resulting in a negative correlation between temperature and voltage.

[0109] Also considering the influence of noisy voltage data, which will reduce the suitability of the updated iterative PID parameters, the desirability parameters of each voltage extreme point are obtained according to the relevant characteristics of the voltage data and temperature data in the preset time domain neighborhood of each voltage extreme point.

[0110] Preferably, in one embodiment of the present invention, considering that normal temperature data and voltage show a negative correlation, the degree of negative correlation between voltage data and temperature data in a preset time domain neighborhood of each voltage extreme point is obtained as a desirability parameter of each voltage extreme point.

[0111] As an example, the preset time domain neighborhood is 7, the collection time of the voltage extreme point is the center point of the preset time domain neighborhood, 3 data are included on the left, and 3 data are included on the right. The voltage data sequence and temperature data sequence corresponding to the voltage extreme point are obtained with the preset time domain neighborhood, and the Pearson correlation coefficient between the voltage data sequence and the temperature data sequence is obtained. The Pearson correlation coefficient is inverted and normalized to the maximum and minimum values, and then used as the desirability parameter of the corresponding voltage extreme point. The Pearson correlation coefficient reflects the negative correlation between the voltage data and the temperature data in the preset time domain neighborhood of each voltage extreme point. The closer the Pearson correlation coefficient is to -1, the greater the negative correlation, the less likely it is a noise point, the stronger the desirability, and the larger the desirability parameter.

[0112] After obtaining the desirability parameters of each voltage extreme point, the fluctuation stability of the voltage extreme point during each update iteration can be analyzed based on the desirability parameters, and the updated stability parameters can be obtained to provide a basis for subsequent determination of the termination of the update iteration. The update iteration can then be terminated according to the updated stability parameters, the PID parameters of the current update iteration can be determined, and the rectifier power supply of the high-power DC furnace can be regulated.

[0113] Preferably, in one embodiment of the present invention, considering that the voltage shows a downward trend during the update iteration process after the addition of materials, when the voltage oscillates more stably, the decreasing trend of the voltage maximum value and the decreasing trend of the voltage minimum value are more consistent, so the functions are fitted to the voltage maximum value and the voltage minimum value respectively, so as to compare the change consistency of the decreasing trend of the voltage maximum value and the decreasing trend of the voltage minimum value, and evaluate the update stability parameter;

[0114] Considering that the Lagrange interpolation polynomial is a commonly used mathematical analysis tool, a function is used to represent a certain internal connection or law between the results. At the same time, considering that the reference values ​​of different voltage maxima are different, that is, the desirability parameters are different, the Lagrange interpolation polynomial is corrected using the desirability parameters:

[0115] The latest update iteration process in the time domain is selected as the target iteration process; a Lagrange interpolation polynomial is constructed for the voltage maximum in the target iteration process to obtain the basis function corresponding to each voltage maximum; the product of all voltage maximums and the corresponding basis functions in the target iteration process is weighted and summed to obtain the trend function of the voltage maximum;

[0116] Similarly, the trend function of the voltage minimum is obtained; the process of obtaining the trend function of the voltage minimum is similar to that of the voltage maximum: a Lagrange interpolation polynomial is constructed for the voltage minimum in the target iteration process to obtain the basis function corresponding to each voltage minimum; with the desirability parameter as the weighted weight, the product of all voltage minima and the corresponding basis function in the target iteration process is weighted summed to obtain the trend function of the voltage minimum;

[0117] Considering that the more stable the difference between the trend function of the maximum voltage value and the trend function of the minimum voltage value, the more consistent the decreasing trend of the maximum voltage value and the decreasing trend of the minimum voltage value, the more stable the voltage oscillation, and the more likely it is to reach the critical P gain parameter, so according to the stable characteristics of the difference between the trend function of the maximum voltage value and the trend function of the minimum voltage value, the updated stable parameter is obtained; the updated stable parameter is positively correlated with the stable characteristics of the difference between the trend functions.

[0118] As an example: the calculation formula for updating the stability parameter includes: ;in, Indicates the first Update stability parameters of the iterative process; Expressed as a natural constant An exponential function with base ; The serial number representing the sampling time of the update iteration process; represents the number of sampling moments of the update iteration process; Indicates The first update iteration process Substitute the value of the trend function of the voltage maximum at each sampling moment; Indicates The first update iteration process Substitute the value of the trend function of the voltage minimum at each sampling moment; Indicates The first update iteration process The maximum and minimum trend differences at the sampling moments; μ represents the The average value of the maximum and minimum trend differences at all sampling moments in the update iteration process; | | indicates the absolute value.

[0119] In the calculation formula for updating the stability parameters, the sampling time in the update iteration process is substituted into the trend function of the voltage maximum value and the trend function of the voltage minimum value. The absolute value of the difference between the calculated function values ​​represents the difference between the trend function of the voltage maximum value and the trend function of the voltage minimum value. The stable characteristics of the difference between the trend function of the voltage maximum and the trend function of the voltage minimum are expressed in the form of The smaller it is, the more stable the difference between the trend function of the voltage maximum and the trend function of the voltage minimum is. After negative correlation mapping and normalization, it is used as an updated stable parameter.

[0120] In another embodiment of the present invention, the trend function of the voltage maximum and the trend function of the voltage minimum can be mapped into a two-dimensional coordinate system, with the horizontal axis being the time axis, the vertical axis being the data axis, the horizontal axis being the sampling time, and the vertical axis being the function value. The DTW distance between the trend function of the voltage maximum and the trend function of the voltage minimum is calculated. The closer the DTW distance is, the more similar the shapes of the trend function of the voltage maximum and the trend function of the voltage minimum are, and the more consistent the decreasing trend of the voltage maximum and the decreasing trend of the voltage minimum are, and the more stable the voltage oscillation is. The DTW distance is mapped through a negative correlation, such as taking the inverse, and then normalized, such as linear normalization, to be used as an updated stability parameter.

[0121] It should be noted that the Lagrange interpolation polynomial and the DTW distance are both technical means well known to those skilled in the art, and will not be described in detail here.

[0122] Preferably, in one embodiment of the present invention, when the update stability parameter is greater than or equal to a preset update stability threshold, the update iteration is terminated; according to the Ziegler-Nichols method, combined with the P gain parameter when the update iteration is terminated, the PID parameter of the current update iteration is obtained.

[0123] As an example, the preset update stability threshold is 0.9. When the update stability parameter is greater than or equal to 0.9, the update iteration is terminated. According to the Ziegler-Nichols method, combined with the P gain parameter when the update iteration is terminated, the PID parameter of the current update iteration is obtained.

[0124] It should be noted that, in one embodiment of the present invention, during the update and iteration process of the feeding update iteration module 104, considering that the temperature in the DC furnace itself is changing and the voltage is being regulated, in order to avoid misjudging the re-iteration moment after feeding, the feeding update determination module 103 needs to stop determining.

[0125] Voltage control module 105: used to control the output voltage of the high-power DC furnace rectifier power supply according to PID parameters.

[0126] After obtaining the PID parameters, the output voltage of the high-power DC furnace rectifier power supply can be controlled according to the PID parameters.

[0127] It should be noted that in an embodiment of the present invention, the DC furnace is controlled by the PID parameters of the initial state in the initial uncharged stage, and is controlled by updated iterative PID parameters after charging. The PID control method is a technical means well known to those skilled in the art and will not be described in detail here.

[0128] An embodiment of the present invention further provides a high-power DC furnace rectifier power supply control method, the control method comprising:

[0129] Get temperature data and voltage data;

[0130] Perform initial iterations on the gain parameters according to a preset time interval; obtain the value parameters of each voltage extreme point based on the difference characteristics between the voltage extreme point and the adjacent data in the voltage data and the acquisition time of the voltage extreme point; analyze the fluctuation stability of the voltage extreme point in each initial iteration process based on the value parameters, and obtain the initial stable parameters of each initial iteration; terminate the initial iteration according to the initial stable parameters, and obtain the PID parameters of the initial state;

[0131] In the preset historical time domain neighborhood at the current moment, the re-iteration moment is determined according to the fluctuation difference characteristics of the adjacent temperature data on both sides of the neighborhood midpoint and the difference characteristics of the voltage data of the neighborhood midpoint and the adjacent data;

[0132] Taking the latest re-iteration moment as the starting point, the gain parameters are updated and iterated according to the preset time interval; according to the relevant characteristics of the voltage data and temperature data in the preset time domain neighborhood of each voltage extreme point, the desirability parameters of each voltage extreme point are obtained; based on the desirability parameters, the fluctuation stability of the voltage extreme point during each update iteration is analyzed to obtain the updated stability parameters; according to the updated stability parameters, the update iteration is terminated and the PID parameters of the current update iteration are determined;

[0133] The output voltage of the high-power DC furnace rectifier power supply is controlled according to the PID parameters.

[0134] In summary, in order to solve the technical problem that the existing PID parameters are not accurately obtained and the stable operation of the high-power DC furnace is affected, the present invention firstly deploys a high-power DC furnace rectifier power supply control system in the high-power DC furnace rectifier power supply control mainboard, obtains temperature data and voltage data through a data acquisition module; obtains the PID parameters of the DC furnace in the initial state in the initial uncharged stage through an initial iteration module; determines the re-iteration time of the PID parameters that need to be re-determined after the DC furnace performance and working state change caused by the charging through a charging update determination module; determines the updated iterative PID parameters of the DC furnace after the charging through a charging update iteration module; and controls the output voltage of the high-power DC furnace rectifier power supply by using the PID parameters through a voltage control module. The present invention adaptively updates the PID parameters through a high-power DC furnace rectifier power supply control system to adapt to different working states of the high-power DC furnace, so that the output voltage of the rectifier power supply is more stable, which is more conducive to the stable operation of the high-power DC furnace.

[0135] It should be noted that the sequence of the above embodiments of the present invention is only for description and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0136] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

Claims

1. A high-power DC furnace rectifier power supply control motherboard, including a control motherboard body, characterized in that: It also includes a high-power DC furnace rectifier power supply control system, which is used to control the high-power DC furnace rectifier power supply: the high-power DC furnace rectifier power supply control system includes a data acquisition module, an initial iteration module, a feed update determination module, a feed update iteration module and a voltage control module; Data acquisition module: used to obtain temperature data and voltage data; Initial iteration module: used to perform initial iteration on the P gain parameter according to a preset time interval; obtain the value parameter of each voltage extreme point according to the difference characteristics between the voltage extreme point and the adjacent data in the voltage data and the acquisition time of the voltage extreme point; analyze the fluctuation stability of the voltage extreme point in each initial iteration process based on the value parameter, and obtain the initial stability parameter of each initial iteration; terminate the initial iteration according to the initial stability parameter, and obtain the PID parameter of the initial state; Feeding update determination module: used to determine the re-iteration time in the preset historical time domain neighborhood at the current moment, according to the fluctuation difference characteristics of the temperature data on both sides of the neighborhood midpoint, combined with the difference characteristics of the voltage data of the neighborhood midpoint and the adjacent data; Feeding update iteration module: used to update and iterate the P gain parameter according to the preset time interval with the latest re-iteration moment as the starting point; obtain the desirability parameter of each voltage extreme point according to the relevant characteristics of the voltage data and temperature data in the preset time domain neighborhood of each voltage extreme point; Based on the desirability parameter, analyzing the fluctuation stability of the voltage extreme point in each update iteration process to obtain an updated stability parameter; terminating the update iteration according to the update stability parameter, and determining the PID parameter of the current update iteration; Voltage control module: used to control the output voltage of the high-power DC furnace rectifier power supply according to the PID parameters; The calculation formula of the value parameter includes: ;in, Indicates The value parameter of the voltage extreme point; represents the hyperbolic tangent function; Indicates the preset adjustment coefficient; Indicates The acquisition time of each voltage extreme point; Indicates The first acquisition moment is also the acquisition moment of the first voltage extreme point; Indicates The data value of the voltage extreme point; Indicates The data value of the data point adjacent to the left side of the voltage extreme point; Indicates The data value of the data point adjacent to the right side of the voltage extreme point; Indicates preset zero-dividing positive parameter; | | indicates taking absolute value; The method for obtaining the initial stable parameters includes: The value parameter of the voltage maximum point is normalized as the maximum weighted weight corresponding to the voltage maximum point; the sum of all the maximum weighted weights of any one of the initial iterations is 1; based on the maximum weighted weights, the voltage maximum point of each initial iteration is weighted and summed to obtain a maximum reference value; according to the difference characteristics between all the voltage maximum points and the maximum reference value of each initial iteration, the maximum error parameter of each initial iteration is obtained; Obtaining a minimum error parameter of each initial iteration; the minimum error parameter is obtained in a similar process to the maximum error parameter; Obtaining an initial stable parameter for each initial iteration according to the minimum error parameter and the maximum error parameter; the minimum error parameter and the maximum error parameter are both negatively correlated with the initial stable parameter; The method for obtaining the desirability parameter includes: Obtaining the degree of negative correlation between voltage data and temperature data in a preset time domain neighborhood of each voltage extreme value point as a desirability parameter of each voltage extreme value point; The method for obtaining the updated stability parameter includes: Select the latest update iteration process in the time domain as the target iteration process; construct a Lagrange interpolation polynomial for the voltage maximum in the target iteration process to obtain the basis function corresponding to each voltage maximum; use the desirability parameter as the weighted weight, perform weighted summation on the product of all the voltage maximums and the corresponding basis functions in the target iteration process to obtain the trend function of the voltage maximum; Obtaining a trend function of a voltage minimum value; the process of obtaining the trend function of the voltage minimum value is similar to the process of obtaining the trend function of the voltage maximum value; According to the stable characteristics of the difference between the trend function of the voltage maximum value and the trend function of the voltage minimum value, an updated stable parameter is obtained; the updated stable parameter is positively correlated with the stable characteristics of the difference between the trend functions.

2. A high-power DC furnace rectifier power supply control mainboard according to claim 1, characterized in that: The DC furnace is controlled by the PID parameters of the initial state in the initial uncharged stage, and is controlled by the updated iterative PID parameters after charging.

3. A high-power DC furnace rectifier power supply control mainboard according to claim 1, characterized in that: The method of terminating the initial iteration according to the initial stable parameters and obtaining the PID parameters of the initial state includes: When the initial stability parameter is greater than or equal to a preset initial stability threshold, the initial iteration is terminated; and according to the Ziegler-Nichols method, the PID parameters of the initial state are obtained in combination with the P gain parameter when the initial iteration is terminated.

4. A high-power DC furnace rectifier power supply control mainboard according to claim 1, characterized in that: The method for obtaining the re-iteration time includes: In the preset historical time domain neighborhood at the current moment, according to the violent fluctuation characteristics of the temperature data on the left side of the neighborhood midpoint, a left temperature fluctuation parameter is obtained; according to the violent fluctuation characteristics of the temperature data on the right side of the neighborhood midpoint, a right temperature fluctuation parameter is obtained; according to the left temperature fluctuation parameter and the right temperature fluctuation parameter, a temperature change parameter is obtained; the left temperature fluctuation parameter and the temperature change parameter are negatively correlated; the right temperature fluctuation parameter and the temperature change parameter are positively correlated; According to the difference characteristics between the voltage data of the midpoint of the neighborhood and the adjacent data on the left, a left voltage difference parameter is obtained; according to the difference characteristics between the voltage data of the midpoint of the neighborhood and the adjacent data on the right, a right voltage difference parameter is obtained; according to the difference between the left voltage difference parameter and the right voltage difference parameter, a voltage change parameter is obtained; An update requirement parameter is obtained according to the temperature change parameter and the voltage change parameter; the temperature change parameter and the voltage change parameter are both positively correlated with the update requirement parameter; when the update requirement parameter is greater than a preset update requirement threshold, it is determined that the PID parameter needs to be re-acquired, and the current moment is used as the re-iteration moment.

5. A high-power DC furnace rectifier power supply control mainboard according to claim 1, characterized in that: The method of terminating the update iteration according to the update stability parameter and determining the PID parameter of the current update iteration includes: When the update stability parameter is greater than or equal to a preset update stability threshold, the update iteration is terminated; and according to the Ziegler-Nichols method, the PID parameter of the current update iteration is obtained in combination with the P gain parameter when the update iteration is terminated.

6. A high-power DC furnace rectifier power supply control method, characterized in that: The control method comprises: Get temperature data and voltage data; Performing initial iterations on the gain parameters according to a preset time interval; obtaining value parameters of each voltage extreme point according to the difference characteristics between the voltage extreme point and the adjacent data in the voltage data and in combination with the acquisition time of the voltage extreme point; analyzing the fluctuation stability of the voltage extreme point in each initial iteration process based on the value parameters, and obtaining initial stable parameters of each initial iteration; terminating the initial iteration according to the initial stable parameters, and obtaining the PID parameters of the initial state; In the preset historical time domain neighborhood at the current moment, the re-iteration moment is determined according to the fluctuation difference characteristics of the temperature data on both sides of the neighborhood midpoint, combined with the difference characteristics of the voltage data at the neighborhood midpoint and the adjacent data; Taking the latest re-iteration moment as the starting point, the gain parameter is updated and iterated according to the preset time interval; according to the relevant characteristics of the voltage data and the temperature data in the preset time domain neighborhood of each voltage extreme point, the desirability parameter of each voltage extreme point is obtained; based on the desirability parameter, the fluctuation stability of the voltage extreme point in each update iteration process is analyzed to obtain the updated stability parameter; according to the updated stability parameter, the update iteration is terminated, and the PID parameter of the current update iteration is determined; Control the output voltage of the high-power DC furnace rectifier power supply according to the PID parameters; The calculation formula of the value parameter includes: ;in, Indicates The value parameter of the voltage extreme point; represents the hyperbolic tangent function; Indicates the preset adjustment coefficient; Indicates The acquisition time of each voltage extreme point; Indicates The first acquisition moment is also the acquisition moment of the first voltage extreme point; Indicates The data value of the voltage extreme point; Indicates The data value of the data point adjacent to the left side of the voltage extreme point; Indicates The data value of the data point adjacent to the right side of the voltage extreme point; Indicates preset zero-dividing positive parameter; | | indicates taking absolute value; The method for obtaining the initial stable parameters includes: The value parameter of the voltage maximum point is normalized as the maximum weighted weight corresponding to the voltage maximum point; the sum of all the maximum weighted weights of any one of the initial iterations is 1; based on the maximum weighted weights, the voltage maximum point of each initial iteration is weighted and summed to obtain a maximum reference value; according to the difference characteristics between all the voltage maximum points and the maximum reference value of each initial iteration, the maximum error parameter of each initial iteration is obtained; Obtaining a minimum error parameter of each initial iteration; the minimum error parameter is obtained in a similar process to the maximum error parameter; Obtaining an initial stable parameter for each initial iteration according to the minimum error parameter and the maximum error parameter; the minimum error parameter and the maximum error parameter are both negatively correlated with the initial stable parameter; The method for obtaining the desirability parameter includes: Obtaining the degree of negative correlation between voltage data and temperature data in a preset time domain neighborhood of each voltage extreme value point as a desirability parameter of each voltage extreme value point; The method for obtaining the updated stability parameter includes: Select the latest update iteration process in the time domain as the target iteration process; construct a Lagrange interpolation polynomial for the voltage maximum in the target iteration process to obtain the basis function corresponding to each voltage maximum; use the desirability parameter as the weighted weight, perform weighted summation on the product of all the voltage maximums and the corresponding basis functions in the target iteration process to obtain the trend function of the voltage maximum; Obtaining a trend function of a voltage minimum value; the process of obtaining the trend function of the voltage minimum value is similar to the process of obtaining the trend function of the voltage maximum value; According to the stable characteristics of the difference between the trend function of the voltage maximum value and the trend function of the voltage minimum value, an updated stable parameter is obtained; the updated stable parameter is positively correlated with the stable characteristics of the difference between the trend functions.

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