A heat expanding production line joint control system

Abstract

The application provides a heat expanding production line joint control system, multiple heat expanding production lines, each of the heat expanding production lines is respectively provided with an induction coil and a hydraulic propulsion subsystem, multiple intermediate frequency power supplies, output ends of each intermediate frequency power supply are selectively electrically connected with the induction coils of each heat expanding production line through an intelligent power distributor, a signal acquisition module is electrically connected with output sides of each intermediate frequency power supply, a parameter calculation module is connected with the signal acquisition module, a health assessment module is connected with the parameter calculation module, and a power scheduling module is connected with the intelligent power distributor and each intermediate frequency power supply. The heat expanding production line joint control system realizes heat expanding production line power collaborative scheduling and coil predictive maintenance.

Description

Technical Field

[0001] This invention belongs to the field of steel pipe hot expansion technology, and in particular relates to a hot expansion production line control system. Background Technology

[0002] The diameter expansion process involves heating the mother tube to its plastic deformation temperature using a medium-frequency induction heating device. A hydraulic propulsion system then drives the mother tube axially along a conical mandrel, expanding the tube diameter to the target size. This is a crucial step in the production of large-diameter seamless steel pipes. In existing hot diameter expansion production systems, each production line is typically equipped with an independent medium-frequency power supply. The lack of a coordinated scheduling mechanism between multiple power supplies results in the equipment operating under light loads for extended periods, leading to low energy efficiency. Simultaneously, the induction coils continuously endure the coupling effect of high-frequency alternating electromagnetic forces and periodic thermal stresses during service. Latent defects such as inter-turn insulation aging and conductor losses lack online monitoring methods, currently relying on periodic manual inspections or emergency repairs after failures. This prevents predictive maintenance at the initial stage of a fault, hindering further improvements in production line reliability. Summary of the Invention

[0003] In view of this, the present invention aims to propose a joint control system for a hot expansion production line to achieve coordinated power scheduling and predictive maintenance of coils in the hot expansion production line.

[0004] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A control system for a hot diameter expansion production line, comprising multiple hot diameter expansion production lines, each of which is equipped with an induction coil and a hydraulic propulsion subsystem; Multiple intermediate frequency power supplies, the number of which is greater than the number of thermal expansion production lines, and the output terminals of each intermediate frequency power supply are selectively electrically connected to the induction coils of each thermal expansion production line through an intelligent power divider. The intelligent power divider is a power switching matrix based on solid-state relays or thyristors. The signal acquisition module is electrically connected to the output side of each of the intermediate frequency power supplies and is used to acquire the voltage and current signals of the output side of each of the intermediate frequency power supplies in real time. A parameter calculation module, connected to the signal acquisition module, is used to calculate the electrical characteristic parameters of each induction coil based on the voltage signal and the current signal. The electrical characteristic parameters include at least the resonant frequency and the equivalent resistance. A health assessment module, connected to the parameter calculation module, is used to generate a health index to characterize the health status of each induction coil based on the deviation of the electrical characteristic parameters of each induction coil from their respective preset reference values, and to identify aging patterns and quantify the degree of deterioration based on the time evolution of the electrical characteristic parameters. A power scheduling module, connected to the intelligent power distributor and each of the intermediate frequency power supplies, is used to control the intelligent power distributor to distribute the output power of each of the intermediate frequency power supplies to each of the thermal expansion production lines according to the real-time power demand of each of the thermal expansion production lines and the health index.

[0005] Furthermore, the signal acquisition module includes a voltage transformer and a current transformer disposed on the output side of each of the intermediate frequency power supplies. The secondary side output of the voltage transformer represents the analog voltage quantity of the voltage signal, and the secondary side output of the current transformer represents the analog current quantity of the current signal. The signal acquisition module also includes an isolated signal conditioning unit connected to the voltage transformer and the current transformer, and a data acquisition card connected to the signal conditioning unit. The sampling frequency of the data acquisition card is not less than 100kHz.

[0006] Furthermore, the parameter calculation module performs a Fast Fourier Transform on the voltage signal and the current signal to extract the fundamental frequency, and uses the fundamental frequency as the resonant frequency; the parameter calculation module calculates the equivalent resistance based on the effective value of the voltage signal, the effective value of the current signal, and the active power; the electrical characteristic parameter also includes a quality factor, which is calculated by the resonant frequency, the equivalent resistance, and the inductance of the induction coil according to the following formula: ; in, For quality factor, The resonant frequency, For inductance, This is the equivalent resistance.

[0007] Furthermore, the health assessment module calculates the health index according to the following formula based on the deviation of the resonant frequency, the deviation of the equivalent resistance, and the deviation of the quality factor: ; ; in, For health index, The deviation from the resonant frequency. The deviation of the equivalent resistance. The deviation of the quality factor is denoted as . , , These are the preset weighting coefficients.

[0008] Furthermore, the health assessment module also includes an early warning submodule, which is set with a first threshold, a second threshold, and a third threshold that decrease sequentially; when the health index is lower than the first threshold, a level one early warning signal is output; when the health index is lower than the second threshold, a level two early warning signal is output; and when the health index is lower than the third threshold, a level three early warning signal is output.

[0009] Furthermore, the health assessment module also includes an aging mode recognition submodule, which distinguishes between the inter-turn insulation aging mode and the conductor loss aging mode of the induction coil based on the ratio of the rate of change of the resonant frequency over time to the rate of change of the equivalent resistance over time. ; in, Let be the derivative of the equivalent resistance with respect to time. The resonant frequency is the derivative with respect to time; the preset reference value of each induction coil is the arithmetic mean of the corresponding electrical characteristic parameters continuously collected and calculated by the parameter calculation module within a preset time period when the induction coil is first put into operation and in a steady state.

[0010] Furthermore, the health assessment module also includes a degradation rate analysis submodule, which records the historical data sequence of the equivalent resistance of each induction coil throughout its entire life cycle and calculates the moving average rate of change of the equivalent resistance within a preset time window. And based on the current value of the equivalent resistance. The preset reference value and the moving average rate of change Calculate the remaining effective lifetime of the induction coil: ; in, For the remaining effective lifespan, The failure threshold of the equivalent resistance; the degradation rate analysis submodule also uses the second derivative of the equivalent resistance with respect to time. The sign indicates the deterioration trend, when When the degradation is determined to be in an accelerated phase, The time is used to determine whether the degradation is in a deceleration or constant rate phase.

[0011] Furthermore, the health assessment module also includes a cooling state decoupling submodule, which acquires the cooling water inlet temperature of each of the induction coils. Outlet water temperature and cooling water flow rate The equivalent resistance is then corrected for temperature compensation according to the following formula: ; in, This is the temperature-corrected equivalent resistance. The measured equivalent resistance is given by κ, where κ is the temperature coefficient of resistance of the conductor material of the induction coil. The temperature of the coil conductor is estimated by calculating the inlet and outlet temperatures of the cooling water and the cooling water flow rate. The preset reference temperature is used; the health assessment module uses the equivalent resistance after temperature correction instead of the measured equivalent resistance to perform health assessment, aging mode identification and remaining effective life calculation.

[0012] Furthermore, the power scheduling module includes: The demand monitoring submodule is connected to the hydraulic propulsion subsystem of each of the hot expansion production lines and is used to calculate the real-time demand power of each of the hot expansion production lines based on the current propulsion speed and current heating temperature of each hot expansion production line. The comparison and judgment submodule is connected to the demand monitoring submodule and is used to compare the real-time demand power of each of the hot expansion production lines with a preset high power threshold and a preset low power threshold. A power allocation submodule, connected to the comparison and judgment submodule and the intelligent power distributor, transfers power quotas from other hot-expansion production lines with real-time power demands less than the low power threshold to the hot-expansion production line when the real-time power demand of any of the hot-expansion production lines exceeds the high power threshold, or activates a backup intermediate frequency power supply and connects it to the hot-expansion production line when there is no power surplus. When the sum of the real-time power demands of all the hot-expansion production lines is less than the product of the total rated power of all currently operating intermediate frequency power supplies and the low power threshold, the power allocation submodule stops the intermediate frequency power supplies that are not carrying any load.

[0013] Furthermore, it also includes a host computer connected to the parameter calculation module, the health assessment module, and the power scheduling module, respectively. The host computer has a human-computer interaction interface developed based on the LabVIEW platform, and the human-computer interaction interface includes: The process monitoring page is used to display the heating temperature, feed speed, hydraulic thrust, and expansion stroke of each of the aforementioned hot expansion production lines; The power supply monitoring page is used to display the output voltage, output current, output power, and power factor of each of the aforementioned intermediate frequency power supplies; The coil monitoring page displays the resonant frequency, equivalent resistance, quality factor, health index, aging mode determination result, and degradation trend determination result of each induction coil.

[0014] Compared with existing technologies, the thermal expansion production line control system described in this invention has the following advantages: (1) The thermal expansion production line control system of the present invention, by collecting the existing voltage and current signals of each intermediate frequency power supply output side, realizes the online extraction of the resonant frequency, equivalent resistance and quality factor of the induction coil without adding additional hardware sensors, and calculates the weighted deviation of multi-dimensional electrical characteristic parameters based on the preset benchmark values ​​independently established by each coil, thereby quantitatively assessing the health status of the coil and establishing a three-level early warning mechanism. On this basis, a discrimination mechanism based on the ratio of the resonant frequency change rate to the equivalent resistance change rate is further introduced, realizing the online identification of two physical modes: inter-turn insulation aging and conductor loss aging. Combined with the moving average change rate of equivalent resistance and the second derivative analysis, the deterioration trend judgment and remaining effective life prediction are realized, which improves the maintenance decision from qualitative judgment to quantitative prediction, effectively solving the problem that the induction coil lacks online health monitoring means and cannot implement predictive maintenance in the prior art; (2) The thermal expansion production line control system described in this invention constructs an N+1 redundant configuration of multiple medium-frequency power supplies sharing an energy pool architecture. Combined with a dynamic scheduling mechanism based on real-time demand power, it realizes dynamic power allocation and collaborative scheduling of medium-frequency power supplies among multiple thermal expansion production lines. The power scheduling module monitors the demand power of each production line in real time. When the demand power is insufficient, it transfers the power quota from the light-load production line or automatically puts the backup power supply into operation. When the demand power decreases, it automatically cuts off the redundant power supply, thereby effectively improving the load rate and energy utilization efficiency of the medium-frequency power supply. It avoids the energy waste caused by each power supply operating independently under light-load conditions for a long time. It realizes the unity of power collaborative scheduling of thermal expansion production line groups and predictive maintenance of coils, and significantly improves equipment utilization and operational reliability. Attached Figure Description

[0015] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the host computer monitoring interface according to an embodiment of the present invention. Detailed Implementation

[0016] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0017] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] The present invention provides a control system for a hot expansion production line, comprising multiple hot expansion production lines, multiple intermediate frequency power supplies, an intelligent power distributor, a signal acquisition module, a parameter calculation module, a health assessment module, a power scheduling module, and a host computer.

[0021] The number of hot-expansion production lines is denoted as M, and each hot-expansion production line is equipped with an induction coil and a hydraulic propulsion subsystem. The number of intermediate frequency power supplies is denoted as N, where N ≥ M + 1, thus achieving an N+1 redundancy configuration. The output terminals of each intermediate frequency power supply are selectively electrically connected to the induction coils of each hot-expansion production line via an intelligent power distributor. The intelligent power distributor is a power switching matrix based on solid-state relays or thyristors. Each input terminal of the power switching matrix is ​​connected to the output terminal of each intermediate frequency power supply, and each output terminal of the power switching matrix is ​​connected to the input terminal of the induction coil of each hot-expansion production line. The control terminal of the power switching matrix is ​​connected to a power scheduling module, thereby achieving selective electrical connection between any intermediate frequency power supply and any hot-expansion production line under the control of the power scheduling module.

[0022] In one embodiment, the signal acquisition module is electrically connected to the output side of each intermediate frequency (IF) power supply to acquire the voltage and current signals from the output side of each IF power supply in real time. Specifically, the signal acquisition module includes voltage transformers and current transformers disposed on the output side of each IF power supply. The secondary side output of the voltage transformer represents the analog voltage quantity of the voltage signal, and the secondary side output of the current transformer represents the analog current quantity of the current signal. Since the IF power supply output is a high-frequency, high-voltage signal, it cannot be directly connected to a data acquisition card. Therefore, the signal acquisition module also includes an isolated signal conditioning unit connected to the voltage and current transformers. This isolated signal conditioning unit converts the analog voltage and analog current quantities into standard analog signals within the range of the data acquisition card, while simultaneously achieving electrical isolation between the primary and secondary sides. The signal acquisition module also includes a data acquisition card connected to the isolated signal conditioning unit. The data acquisition card converts the standard analog signals into digital signals for processing by the parameter calculation module. To ensure complete acquisition of the IF signal waveform, the sampling frequency of the data acquisition card is not less than 100kHz.

[0023] In one embodiment, the parameter calculation module is connected to the signal acquisition module and is used to calculate the electrical characteristic parameters of each induction coil based on the voltage and current signals. These electrical characteristic parameters include at least the resonant frequency and the equivalent resistance. Specifically, the parameter calculation module performs a Fast Fourier Transform on the voltage and current signals to extract the fundamental frequency. After converting the time-domain signal to the frequency domain, it extracts the frequency component with the largest amplitude in the spectrum as the fundamental frequency and uses this fundamental frequency as the resonant frequency. The parameter calculation module calculates the equivalent resistance based on the effective values ​​of the voltage and current signals and the active power. The effective voltage and current values ​​are calculated using the root mean square algorithm, and the active power is calculated using time-domain integration. Electrical characteristic parameters also include the quality factor. The parameter calculation module calculates the parameters based on the resonant frequency. Equivalent resistance and the inductance of the induction coil According to the formula Calculate the quality factor, where the inductance L is a known design parameter of the induction coil, determined by the coil's geometry and number of turns, and is pre-entered during system configuration.

[0024] Specifically, the health assessment module is connected to the parameter calculation module. It generates a health index characterizing the health status of each induction coil based on the deviation of its electrical characteristic parameters from their respective preset benchmark values. It also identifies aging patterns and quantifies the degree of degradation based on the time evolution of the electrical characteristic parameters. The preset benchmark value for each induction coil is the arithmetic mean of the corresponding electrical characteristic parameters continuously collected and calculated by the parameter calculation module within a preset time period when the induction coil is first put into operation and in a steady-state condition. Specifically, after a new induction coil is installed and put into normal operation, the system automatically enters the benchmark establishment mode, continuously collecting operating data for a preset time period (e.g., 24 hours). After excluding data from start-up / shutdown phases and abnormal operating conditions, the resonant frequency is calculated. Equivalent resistance and quality factor The arithmetic mean of the values ​​is stored in the database as the health benchmark for the coil. Different induction coils have their own independent benchmark values ​​due to manufacturing differences, and these values ​​are not interchangeable.

[0025] The health assessment module is based on the deviation from the resonant frequency. Deviation of equivalent resistance Deviation from quality factor Calculate the health index The health index is calculated using a formula. ; Calculation, where , , These are the preset weighting coefficients, and Health Index The value ranges from 0 to 100%, with higher values ​​indicating better coil health.

[0026] In one embodiment, the health assessment module further includes an early warning submodule. The early warning submodule is configured with a first threshold, a second threshold, and a third threshold that decrease sequentially. When the health index falls below the first threshold, a level one early warning signal is output; when the health index falls below the second threshold, a level two early warning signal is output; and when the health index falls below the third threshold, a level three early warning signal is output. The three levels of early warning signals correspond to different maintenance strategies: a level one early warning prompts maintenance personnel to pay attention and strengthen inspections; a level two early warning suggests scheduled planned shutdown maintenance during the nearest production break; and a level three early warning requires immediate shutdown for inspection.

[0027] In one embodiment, the health assessment module further includes an aging pattern recognition submodule. The aging pattern recognition submodule identifies the aging pattern based on the rate of change of the resonant frequency over time. With the rate of change of equivalent resistance over time The ratio of the two values ​​is used to distinguish between the inter-turn insulation aging mode and the conductor loss aging mode of the induction coil. The physical principle is that inter-turn insulation aging leads to a reduction in the effective number of turns or a change in the distributed capacitance of the coil, affecting the resonant frequency. Significant changes and equivalent resistance The changes are relatively small, therefore The ratio is relatively large; conductor loss aging leads to an increase in equivalent resistance. The resonant frequency rises significantly. The change is relatively small, therefore the ratio is small. The specific judgment logic is: when and When the time is right, it is determined to be the dominant mode of inter-turn insulation aging; when and When this occurs, the system determines that the conductor loss aging mode is dominant. The threshold value is preset by the system based on historical data and coil type.

[0028] In one embodiment, the health assessment module further includes a degradation rate analysis submodule. The degradation rate analysis submodule records the equivalent resistance of each induction coil. The moving average rate of change of the equivalent resistance is calculated using historical data sequences over the entire lifespan, within a preset time window. Moving average rate of change The calculation method is as follows: taking the current time as the endpoint, performing linear regression on the historical equivalent resistance data within a preset time window, to obtain... The degradation rate analysis submodule is based on the current value of the equivalent resistance. Preset baseline value and moving average rate of change Calculate the remaining effective lifespan of the induction coil: when hour, ;when If the induction coil is determined to have not experienced conductor loss aging, its remaining effective lifespan is not calculated. For the remaining effective lifespan, The failure threshold is the equivalent resistance. The degradation rate analysis submodule also considers the second derivative of the equivalent resistance with respect to time. The sign indicates the deterioration trend, when When the degradation is determined to be in an accelerated phase, The time frame determines whether the degradation is in a deceleration or constant-rate phase. The second derivative is calculated using the moving average rate of change. The time series is differentiated again. When the degradation is in the accelerated stage, it indicates that the coil aging is intensifying and the maintenance cycle should be shortened; when the degradation is in the deceleration or constant stage, it indicates that the aging process is relatively stable and maintenance can be performed according to the normal cycle.

[0029] In one embodiment, the health assessment module further includes a cooling state decoupling submodule. The cooling state decoupling submodule acquires the cooling water inlet temperature of each induction coil. Outlet water temperature and cooling water flow rate and according to the formula ; Temperature compensation correction is applied to the equivalent resistance. This is the temperature-corrected equivalent resistance. For the actual measured equivalent resistance, The temperature coefficient of resistance of the conductor material of the induction coil. To estimate the temperature of the coil conductors, calculated from the inlet and outlet temperatures of the cooling water and the cooling water flow rate. Preset reference temperature. Estimated temperature of coil conductors. Based on the principle of energy balance, the heat generated by the coil is equal to the heat carried away by the cooling water. The coil power loss is approximately equal to the difference between the active power of the intermediate frequency power supply and the transmission efficiency. The transmission efficiency is the efficiency of transmission between the intermediate frequency power supply and the induction coil. From this, the temperature of the coil conductor can be estimated. The health assessment module uses the temperature-corrected equivalent resistance. Replacement of measured equivalent resistance Health assessments, aging pattern identification, and remaining effective life calculations are performed to eliminate the interference of cooling condition fluctuations on health assessment results.

[0030] Specifically, the power scheduling module connects to the intelligent power distributor and each intermediate frequency power supply. It controls the intelligent power distributor to allocate the output power of each intermediate frequency power supply to each hot-expansion production line based on the real-time power demand and health index of each line. The power scheduling module includes a demand monitoring submodule, a comparison and judgment submodule, and a power allocation submodule.

[0031] Specifically, the demand monitoring submodule connects to the hydraulic propulsion subsystem of each hot expansion production line to calculate the real-time power demand of each line based on its current propulsion speed and heating temperature. The real-time power demand of the hot expansion production line includes heating power and propulsion power. Heating power is related to heating temperature, steel pipe specifications, and propulsion speed, while propulsion power is related to propulsion speed and deformation resistance. The demand monitoring submodule calculates the real-time power demand by collecting real-time data on hydraulic system pressure and flow, and the setpoint and actual values ​​of the temperature control system, combined with a pre-calibrated power model. .

[0032] In one embodiment, the comparison and judgment submodule is connected to the demand monitoring submodule to determine the real-time power demand of each thermal expansion production line. With preset high power threshold and preset low power threshold A comparison is made. The high power threshold and low power threshold are based on the rated power of a single intermediate frequency power supply. In one implementation, the setting is... =0.85× , =0.30× .when > When this occurs, it indicates that the production line is under high load; when < When this occurs, it indicates that the production line is under light load.

[0033] Specifically, the power allocation submodule is connected to the comparison and judgment submodule and the intelligent power distributor. When the real-time power demand of any hot-expansion production line exceeds the high power threshold, the power allocation submodule first checks if any other operating production lines have a real-time power demand below the low power threshold. If so, the power quota is transferred from the lightly loaded production line to the production line with insufficient power demand. If all other production lines have no power surplus, or if the demand still cannot be met after the transfer, the power allocation submodule sends a command to the intelligent power distributor to start the backup intermediate frequency power supply and connect it to the hot-expansion production line. When the sum of the real-time power demand of all hot-expansion production lines is less than the product of the total rated power of all currently operating intermediate frequency power supplies and the low power threshold, it indicates that there are too many power supplies currently in operation. The power allocation submodule outputs a shutdown command to the intermediate frequency power supply that is not carrying any load, switching it from the operating state to the standby state. The above power allocation logic is executed cyclically at a preset period to ensure that the power allocation follows the changes in production line load in real time.

[0034] In one embodiment, such as Figure 1As shown, the system also includes a host computer connected to the parameter calculation module, health assessment module, and power scheduling module, respectively. The host computer has a human-machine interface developed based on the LabVIEW platform. The human-machine interface includes a process monitoring page, a power supply monitoring page, a coil monitoring page, and an alarm log page. The process monitoring page displays the heating temperature, feed speed, hydraulic thrust, and expansion stroke of each hot-expansion production line. The power supply monitoring page displays the output voltage, output current, output power, and power factor of each intermediate frequency power supply. The coil monitoring page displays the resonant frequency, equivalent resistance, quality factor, health index, aging mode judgment result, and degradation trend judgment result of each induction coil. Each parameter is presented in both numerical and trend curve formats. The health index is displayed as a progress bar, and the aging mode judgment result and degradation trend judgment result are displayed as text labels. The alarm log page records and displays the trigger time, warning level, and corresponding induction coil number of each warning signal. All warning events are automatically stored in the database, supporting conditional retrieval and export, facilitating fault analysis and maintenance plan development by maintenance personnel.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A control system for a hot expansion production line, characterized in that: Multiple hot expansion production lines, each equipped with an induction coil and a hydraulic propulsion subsystem; Multiple intermediate frequency power supplies, the number of which is greater than the number of thermal expansion production lines, and the output terminals of each intermediate frequency power supply are selectively electrically connected to the induction coils of each thermal expansion production line through an intelligent power divider. The intelligent power divider is a power switching matrix based on solid-state relays or thyristors. The signal acquisition module is electrically connected to the output side of each of the intermediate frequency power supplies and is used to acquire the voltage and current signals of the output side of each of the intermediate frequency power supplies in real time. A parameter calculation module, connected to the signal acquisition module, is used to calculate the electrical characteristic parameters of each induction coil based on the voltage signal and the current signal. The electrical characteristic parameters include at least the resonant frequency and the equivalent resistance. A health assessment module, connected to the parameter calculation module, is used to generate a health index to characterize the health status of each induction coil based on the deviation of the electrical characteristic parameters of each induction coil from their respective preset reference values, and to identify aging patterns and quantify the degree of deterioration based on the time evolution of the electrical characteristic parameters. A power scheduling module, connected to the intelligent power distributor and each of the intermediate frequency power supplies, is used to control the intelligent power distributor to distribute the output power of each of the intermediate frequency power supplies to each of the thermal expansion production lines according to the real-time power demand of each of the thermal expansion production lines and the health index.

2. The thermal expansion production line control system according to claim 1, characterized in that: The signal acquisition module includes a voltage transformer and a current transformer disposed on the output side of each of the intermediate frequency power supplies. The secondary side output of the voltage transformer represents the analog voltage quantity of the voltage signal, and the secondary side output of the current transformer represents the analog current quantity of the current signal. The signal acquisition module also includes an isolated signal conditioning unit connected to the voltage transformer and the current transformer, and a data acquisition card connected to the signal conditioning unit. The sampling frequency of the data acquisition card is not less than 100kHz.

3. The control system for a hot expansion production line according to claim 1, characterized in that: The parameter calculation module performs a Fast Fourier Transform on the voltage signal and the current signal to extract the fundamental frequency, and uses the fundamental frequency as the resonant frequency; the parameter calculation module calculates the equivalent resistance based on the effective value of the voltage signal, the effective value of the current signal, and the active power; the electrical characteristic parameters also include a quality factor, which is calculated by the resonant frequency, the equivalent resistance, and the inductance of the induction coil according to the following formula: ； in, For quality factor, The resonant frequency, For inductance, This is the equivalent resistance.

4. The thermal expansion production line control system according to claim 1, characterized in that: The health assessment module calculates the health index according to the following formula based on the deviation of the resonant frequency, the deviation of the equivalent resistance, and the deviation of the quality factor: ； ； in, For health index, The deviation from the resonant frequency. The deviation of the equivalent resistance. The deviation of the quality factor. , , These are the preset weighting coefficients.

5. The thermal expansion production line control system according to claim 4, characterized in that: The health assessment module also includes an early warning submodule, which is set with a first threshold, a second threshold, and a third threshold that decrease sequentially. When the health index is lower than the first threshold, a level one early warning signal is output; when the health index is lower than the second threshold, a level two early warning signal is output; and when the health index is lower than the third threshold, a level three early warning signal is output.

6. The control system for a hot expansion production line according to claim 1, characterized in that: The health assessment module further includes an aging mode recognition submodule, which distinguishes between the inter-turn insulation aging mode and the conductor loss aging mode of the induction coil based on the ratio of the rate of change of the resonant frequency over time to the rate of change of the equivalent resistance over time. ； in, Let be the derivative of the equivalent resistance with respect to time. The resonant frequency is the derivative with respect to time; the preset reference value of each induction coil is the arithmetic mean of the corresponding electrical characteristic parameters continuously collected and calculated by the parameter calculation module within a preset time period when the induction coil is first put into operation and in a steady state.

7. The control system for a hot expansion production line according to claim 1, characterized in that: The health assessment module also includes a degradation rate analysis submodule, which records the historical data sequence of the equivalent resistance of each induction coil throughout its entire life cycle and calculates the moving average rate of change of the equivalent resistance within a preset time window. And based on the current value of the equivalent resistance. The preset reference value and the moving average rate of change Calculate the remaining effective lifetime of the induction coil: ； in, For the remaining effective lifespan, The failure threshold of the equivalent resistance; the degradation rate analysis submodule also uses the second derivative of the equivalent resistance with respect to time. The sign indicates the deterioration trend, when When the degradation is determined to be in an accelerated phase, The time is used to determine whether the degradation is in a deceleration or constant rate phase.

8. The control system for a hot expansion production line according to claim 1, characterized in that: The health assessment module also includes a cooling state decoupling submodule, which acquires the cooling water inlet temperature of each of the induction coils. Outlet water temperature and cooling water flow rate The equivalent resistance is then corrected for temperature compensation according to the following formula: ； in, This is the temperature-corrected equivalent resistance. The measured equivalent resistance is given by κ, where κ is the temperature coefficient of resistance of the conductor material of the induction coil. The temperature of the coil conductor is estimated by calculating the inlet and outlet temperatures of the cooling water and the cooling water flow rate. The preset reference temperature is used; the health assessment module uses the equivalent resistance after temperature correction instead of the measured equivalent resistance to perform health assessment, aging mode identification and remaining effective life calculation.

9. The control system for a hot expansion production line according to claim 1, characterized in that: The power scheduling module includes: The demand monitoring submodule is connected to the hydraulic propulsion subsystem of each of the hot expansion production lines and is used to calculate the real-time demand power of each of the hot expansion production lines based on the current propulsion speed and current heating temperature of each hot expansion production line. The comparison and judgment submodule is connected to the demand monitoring submodule and is used to compare the real-time demand power of each of the hot expansion production lines with a preset high power threshold and a preset low power threshold. A power allocation submodule, connected to the comparison and judgment submodule and the intelligent power distributor, transfers power quotas from other hot-expansion production lines with real-time power demands less than the low power threshold to the hot-expansion production line when the real-time power demand of any of the hot-expansion production lines exceeds the high power threshold, or activates a backup intermediate frequency power supply and connects it to the hot-expansion production line when there is no power surplus. When the sum of the real-time power demands of all the hot-expansion production lines is less than the product of the total rated power of all currently operating intermediate frequency power supplies and the low power threshold, the power allocation submodule stops the intermediate frequency power supplies that are not carrying any load.

10. The thermal expansion production line control system according to claim 1, characterized in that: It also includes a host computer connected to the parameter calculation module, the health assessment module, and the power scheduling module, respectively. The host computer has a human-computer interaction interface developed based on the LabVIEW platform, and the human-computer interaction interface includes: The process monitoring page is used to display the heating temperature, feed speed, hydraulic thrust, and expansion stroke of each of the aforementioned hot expansion production lines; The power supply monitoring page is used to display the output voltage, output current, output power, and power factor of each of the aforementioned intermediate frequency power supplies; The coil monitoring page displays the resonant frequency, equivalent resistance, quality factor, health index, aging mode determination result, and degradation trend determination result of each induction coil.

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