A heating control system and method for a large cavity press

Abstract

An embodiment of the present invention provides a heating control system and method for a large cavity press, which is applied to the field of temperature control systems. The heating control system includes a heating control device, a programmable AC power supply, a multimeter, a transformer and a heater, wherein the heater is a resistive load in the large cavity press; the heating control device sends a control instruction to the programmable AC power supply and a measurement instruction to the multimeter; the programmable AC power supply generates an AC voltage and applies it to the primary side of the transformer; the transformer regulates the AC voltage, and applies the regulated voltage to both ends of the heater to heat the heater; the multimeter collects the primary side voltage value output by the programmable AC power supply in the current power cycle and sends it to the heating control device; the heating control device calculates the voltage value required to generate the AC wave in the next power cycle, and sends a control instruction containing the voltage value to the programmable AC power supply to perform subsequent heating control, thereby improving the control accuracy and stability of the heating system of the large cavity press.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature control systems, and in particular to a heating control system and method for a large cavity press. Background Art

[0002] A large cavity press is a static high-pressure device used for the synthesis and preparation of new materials, simulating the internal environment of the earth, and in-situ characterization of wave velocity, conductivity, X-ray spectrum, etc. under high pressure and high temperature. At present, a large cavity press can usually produce high pressure conditions below 30GPa (million atmospheres). In order to enable the large cavity press to provide high temperature conditions at the same time, a heating system is usually equipped for the large cavity press, so that the large cavity press can produce high temperature conditions of 2000℃ (degrees Celsius) and above under a pressure environment above 5 GPa.

[0003] In the related art, the heating system of the large cavity press usually adopts a power and temperature control system based on a thyristor (also called a power regulator). The system schematic diagram of the control system is as follows: Figure 1 shown. Figure 1 In the process, the bidirectional thyristor chops the wave corresponding to the voltage generated by the power supply (constant current source), and then adjusts the voltage through the transformer and applies it to both ends of the heater of the large cavity press, and the heater is heated. Among them, the waveform corresponding to the voltage generated by the power supply is as follows Figure 2a As shown, the voltage waveform after bidirectional thyristor chopping is as follows Figure 2b As shown, the voltage waveform after voltage regulation by the transformer is as follows Figure 2c As shown, the voltage waveform of the voltage applied to both ends of the heater is as follows Figure 2c shown. Figure 1 The core of the heating system of the large cavity press shown is to change the trigger angle (or conduction angle) within the power cycle, that is, the high-frequency on-off circuit, to change the effective value of the voltage applied to the two ends of the heater of the large cavity press, and then adjust the power and temperature of the heater to achieve high temperature conditions of the large cavity press.

[0004] However, in implementing Figure 1 During the heating process of the large cavity press shown in the figure, it was found that the bidirectional thyristor had inaccuracy in chopping the wave corresponding to the voltage generated by the power supply, and because the wave corresponding to the power supply voltage was chopped, the crest factor (the ratio of the maximum value to the effective value) of the voltage and current was large when the trigger power was low, and thus the corresponding AC signal could not be accurately measured, resulting in poor control accuracy and stability of the heating system. Summary of the invention

[0005] The purpose of the embodiment of the present invention is to provide a heating control system and method for a large cavity press to improve the control accuracy and stability of the heating system of the large cavity press. The specific technical solution is as follows:

[0006] An embodiment of the present invention provides a heating control system for a large cavity press, the heating control system comprising: a heating control device, a programmable AC power supply, a multimeter, a transformer and a heater; the heater is a resistive load arranged in a pressure transmission medium of the large cavity press; the heating control device is connected to the programmable AC power supply and the multimeter respectively, the programmable AC power supply is connected to the transformer, and the transformer is connected to the heater;

[0007] The heating control device is used to calculate the sub-target values ​​corresponding to different temperature rise time intervals according to the set target value to be adjusted and the temperature rise time; send a control instruction to the programmable AC power supply, and send a measurement instruction to the multimeter; the control instruction is used to indicate the power cycle of the programmable AC power supply and the frequency of the AC wave generated in the power cycle; the measurement instruction is used to indicate the data acquisition cycle and data acquisition frequency of the multimeter; the power cycle is the same as the data acquisition cycle; the target value to be adjusted is a target power value, a target voltage value or a target temperature value;

[0008] The programmable AC power supply is used to receive the control instruction, generate a corresponding AC voltage according to the power cycle and the frequency of the AC wave generated in the power cycle, and apply the AC voltage to the primary side of the transformer;

[0009] The transformer is used to adjust the AC voltage according to a set gear, and apply the adjusted voltage to both ends of the heater to heat the heater;

[0010] The multimeter is used to receive the measurement instruction, collect the voltage output by the programmable AC power supply in the current power cycle according to the data collection frequency to obtain a primary side voltage value, and send the primary side voltage value to the heating control device;

[0011] The heating control device is also used to receive the primary side voltage value, calculate the voltage value of the AC wave required to generate the next power supply cycle based on the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power supply cycle, and send a control instruction containing the voltage value of the AC wave required to generate the next power supply cycle to the programmable AC power supply for subsequent heating control.

[0012] Optionally, when the target value to be adjusted is a target voltage value, the heating control device is specifically used to calculate sub-target voltage values ​​corresponding to different temperature rise time intervals according to the set target voltage value and temperature rise time;

[0013] The heating control device is specifically used to calculate the voltage value of the AC wave required to be generated in the next power cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power cycle using the following expression:

[0014]

[0015] in, The voltage value of the AC wave required to generate the next power cycle, is the sub-target voltage value output by the programmable AC power supply in the temperature rise time interval corresponding to the current power cycle, is the primary side voltage value, and n is a setting parameter.

[0016] Optionally, when the target value to be adjusted is a target power value, there are multiple multimeters, and the heating control device is specifically used to calculate sub-target power values ​​corresponding to different temperature rise time intervals according to the set target power value and temperature rise time;

[0017] The multimeter is used to collect the voltage output by the transformer in the current power cycle according to the data collection frequency to obtain the secondary side voltage value, and collect the current output by the transformer in the current power cycle to obtain the secondary side current value, and send the secondary side voltage value and the secondary side current value to the heating control device;

[0018] The heating control device is specifically used to calculate the voltage value of the AC wave required to be generated in the next power cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power cycle using the following expression:

[0019]

[0020] in, is the voltage value of the AC wave required to be generated in the next power cycle, P is the sub-target power value output by the transformer in the temperature rise time interval corresponding to the current power cycle, is the secondary side voltage value, is the secondary current value, is the primary side voltage value, and n is a setting parameter.

[0021] Optionally, in the case where the target value to be adjusted is a target temperature value, there are multiple multimeters, and the target power value corresponding to the target temperature value is determined according to a preset correspondence between temperature and power, and the heating control device is specifically used to calculate sub-target power values ​​corresponding to different temperature rise time intervals according to the target power value corresponding to the target temperature value and the temperature rise time;

[0022] The multimeter is used to collect the voltage output by the transformer in the current power cycle according to the data collection frequency to obtain the secondary side voltage value, and collect the current output by the transformer in the current power cycle to obtain the secondary side current value, and send the secondary side voltage value and the secondary side current value to the heating control device;

[0023] The heating control device is specifically used to calculate the voltage value of the AC wave required to be generated in the next power cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power cycle using the following expression:

[0024]

[0025] in, is the voltage value of the AC wave required to be generated in the next power cycle, P is the sub-target power value output by the transformer in the temperature rise time interval corresponding to the current power cycle, is the secondary side voltage value, is the secondary current value, is the primary side voltage value, and n is a setting parameter.

[0026] Optionally, the multimeter is specifically used for:

[0027] Collecting the voltage output by the programmable AC power supply at the data collection frequency during the current power cycle, and calculating the effective value of the collected voltage to obtain a primary side voltage value;

[0028] Collecting the voltage output by the transformer at the data collection frequency during the current power supply cycle, and calculating the effective value of the collected voltage to obtain a secondary side voltage value;

[0029] The current output by the transformer is collected according to the data collection frequency during the current power supply cycle, and the effective value of the collected current is calculated to obtain the secondary side current value.

[0030] Optionally, the heater is a resistive load of a conductor or semiconductor material, the conductor material includes: graphite and rhenium sheet, and the semiconductor material includes: lanthanum chromate, boron-doped diamond, titanium diboride and titanium carbide.

[0031] Optionally, the heating control system further comprises: a thermocouple, wherein the thermocouple is built into the center of the cavity of the heater;

[0032] The multimeter is also used to measure and collect the thermoelectromotive force generated by the thermocouple in the current power supply cycle, and send the thermoelectromotive force to the heating control device.

[0033] Optionally, the heating control device includes an interactive display module and a command control module;

[0034] The command control module is used to receive the thermoelectromotive force and determine the temperature value corresponding to the thermoelectromotive force according to a preset corresponding relationship between the thermoelectromotive force and the temperature;

[0035] The interactive display module is used to display at least one of the following: the target value to be adjusted, the temperature rise time, the sub-target values ​​corresponding to the different temperature rise time intervals, the primary side voltage value, the secondary side voltage value, the secondary side current value sent by the multimeter in each power supply cycle, and the temperature value determined according to the thermoelectromotive force sent by the multimeter.

[0036] Optionally, the AC wave includes: a sinusoidal AC wave and a triangular wave.

[0037] The embodiment of the present invention further provides a heating control method for a large cavity press, which is applied to any of the above-mentioned heating control systems for the large cavity press, and the method comprises:

[0038] The heating control device calculates sub-target values ​​corresponding to different temperature rise time intervals according to the set target value to be adjusted and the temperature rise time; the target value to be adjusted is a target power value, a target voltage value or a target temperature value;

[0039] The heating control device sends a control instruction to the programmable AC power supply, and sends a measurement instruction to the multimeter; the control instruction is used to indicate the power cycle of the programmable AC power supply and the frequency of the AC wave generated in the power cycle, and the measurement instruction is used to indicate the data acquisition cycle and data acquisition frequency of the multimeter, and the power cycle is the same as the data acquisition cycle;

[0040] The programmable AC power supply receives the control instruction, generates a corresponding AC voltage according to the power cycle and the frequency of the AC wave generated in the power cycle, and applies the AC voltage to the primary side of the transformer;

[0041] The transformer regulates the AC voltage according to the set gear, and applies the regulated voltage to both ends of the heater to heat the heater;

[0042] The multimeter receives the measurement instruction, and acquires the voltage output by the programmable AC power supply in the current power cycle according to the data acquisition frequency to obtain a primary side voltage value, and sends the primary side voltage value to the heating control device;

[0043] The heating control device receives the primary side voltage value, calculates the voltage value of the AC wave required to generate the next power supply cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power supply cycle, and sends a control instruction containing the voltage value of the AC wave required to generate the next power supply cycle to the programmable AC power supply, returns to execute the step of the programmable AC power supply receiving the control instruction, generating a corresponding AC wave within the power supply cycle, and sending the electrical signal corresponding to the AC wave to the transformer, and performing subsequent heating control.

[0044] Beneficial effects of the embodiments of the present invention:

[0045] A heating control system and method for a large cavity press provided in an embodiment of the present invention utilizes the high voltage regulation accuracy of a programmable AC power supply, can control the power supply output voltage and current with higher accuracy, and utilizes the full cycle of the AC wave for output. Compared with the chopping method of a bidirectional thyristor, the voltage and current crest factors are smaller, thereby being able to accurately measure the AC signal, and collect the voltage output by the programmable AC power supply in each power cycle, thereby achieving high-speed collection of AC signals. The collected voltage value is used to calculate the voltage value of the AC wave required to generate the next power cycle, and is applied to subsequent heating control, so that measurement and control are performed alternately, and the temperature changes of the heater can be quickly responded to, thereby improving the control accuracy and stability of the heating system of the large cavity press.

[0046] Of course, it is not necessary to achieve all of the advantages described above at the same time to implement any product or method of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0048] Figure 1 It is a system schematic diagram of a heating system of a large cavity press in the related art;

[0049] Figure 2a It is a schematic diagram of a power supply output voltage waveform in the related art;

[0050] Figure 2b It is a schematic diagram of the voltage waveform after chopping in the related art;

[0051] Figure 2c It is a schematic diagram of voltage waveform after voltage regulation in the related art;

[0052] Figure 3A schematic structural diagram of a heating control system for a large cavity press provided by an embodiment of the present invention;

[0053] Figure 4 Another structural schematic diagram of a heating control system for a large cavity press provided by an embodiment of the present invention;

[0054] Figure 5 A schematic diagram of the interaction of various components in a heating control system for a large cavity press provided by an embodiment of the present invention;

[0055] Figure 6 A schematic flow chart of a heating control method for a large cavity press provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field based on the present invention belong to the scope of protection of the present invention.

[0057] In the related art, the principle is usually adopted. Figure 1 The heating system of the large cavity press shown in the figure achieves high temperature conditions of the large cavity press by changing the trigger angle (or conduction angle) in the power cycle to change the effective value of the voltage applied to the two ends of the heater of the large cavity press. Figure 1 The following deficiencies were found in the heating system of the large cavity press shown:

[0058] 1) When the constant power control heater is used for heating, the power fluctuation of the heating system is usually ±1-2 W (watts). Since the pressure transmission medium used by the large cavity press to generate higher pressure is smaller, the heater placed in it is smaller and more sensitive to power changes. This will cause temperature fluctuations of ±5-10℃ or even greater for large cavity presses above 10GPa, which cannot meet the temperature control requirements in applications such as single crystal growth under high temperature and high pressure.

[0059] 2) The power control of the heating system is based on the PID (Proportion Integral Differential) method. Different high temperature and high pressure conditions require heaters of different sizes and materials. Therefore, it is necessary to optimize and adjust the PID parameters in different scenarios, and the implementation process is complicated.

[0060] 3) A bidirectional thyristor is required to chop the wave corresponding to the power supply output voltage to control the effective value of the voltage applied to both ends of the heater. On the one hand, it is difficult to perform accurate chopping; on the other hand, when the trigger power is low, the CF (Crest factor) of the voltage and current will be greater than 4, and the conventional AC effective value measurement method can only accurately measure the AC signal with a crest factor less than 4, that is, it is impossible to accurately measure the corresponding AC signal, resulting in poor control accuracy and stability of the heating system. For example, the power supply output voltage is a sinusoidal voltage, and its waveform can be described as: , Indicates the conduction angle corresponding to the voltage, in the first positive half cycle of the voltage waveform After adding the thyristor, the conduction angle of the voltage waveform in the positive half cycle is , at this time only The voltage of the segment is turned on. Correspondingly, the effective value of the voltage in this half cycle is: , the corresponding peak value is: , represents the on-time, then CF is:

[0061]

[0062] By plotting the voltage peak value, it can be seen that when the conduction angle is less than about 30 degrees, the crest factor is greater than 4.

[0063] 4) The heating system of the large cavity press is mainly used for large-sized heating furnaces (with a size of tens of centimeters or more) for industrial production. The temperature or power change rate of the large-sized heating furnace is small (such as 10℃ / min (degrees Celsius per minute)), and there is a lag in the heating cavity reaching the set temperature. However, the size of the heater in the large cavity press is in the millimeter level, and a faster heating rate (such as 100℃ / min) is often used, which can easily cause power and temperature overshoot or even loss of control.

[0064] 5) For semiconductor heaters such as lanthanum chromate, the heater must first reach a certain on-voltage before it starts to heat up. Then the carrier concentration rises rapidly with the temperature, and the heater resistance drops sharply. However, due to the low power at this stage, the thyristor-based heating system has inaccurate measurements and poor control stability. If the PID parameters are not set properly, the heating can easily get out of control, causing the heater to burn out or "blow up."

[0065] In order to solve at least one of the above problems, an embodiment of the present invention provides a heating control system and method for a large cavity press. The heating control system for a large cavity press provided by an embodiment of the present invention includes: a heating control device, a programmable AC power supply, a multimeter, a transformer, and a heater; the heater is a resistive load arranged in the pressure transmission medium of the large cavity press; the heating control device is connected to the programmable AC power supply and the multimeter respectively, the programmable AC power supply is connected to the transformer, and the transformer is connected to the heater;

[0066] A heating control device, used for calculating sub-target values ​​corresponding to different temperature rise time intervals according to a set target value to be adjusted and a temperature rise time; sending a control instruction to a programmable AC power supply, and sending a measurement instruction to a multimeter; the control instruction is used to indicate a power cycle of the programmable AC power supply and a frequency of an AC wave generated within the power cycle; the measurement instruction is used to indicate a data acquisition cycle and a data acquisition frequency of the multimeter; the power cycle is the same as the data acquisition cycle; the target value to be adjusted is a target power value, a target voltage value or a target temperature value;

[0067] A programmable AC power supply, which is used to receive control instructions and generate a corresponding AC voltage according to a power cycle and the frequency of the AC wave generated in the power cycle, and apply the AC voltage to the primary side of the transformer;

[0068] The transformer is used to adjust the AC voltage according to the set gear, and apply the adjusted voltage to both ends of the heater to make the heater heat;

[0069] A multimeter, used for receiving a measurement instruction, collecting the voltage output by the programmable AC power supply in the current power cycle according to a data collection frequency to obtain a primary side voltage value, and sending the primary side voltage value to a heating control device;

[0070] The heating control device is also used to receive the primary side voltage value, calculate the voltage value of the AC wave required to generate the next power supply cycle based on the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power supply cycle, and send a control instruction containing the voltage value of the AC wave required to generate the next power supply cycle to the programmable AC power supply for subsequent heating control.

[0071] The heating control system for a large cavity press provided in an embodiment of the present invention utilizes the high voltage regulation accuracy of a programmable AC power supply, can control the power supply output voltage and current with high accuracy, and utilizes the full cycle of the AC wave for output. Compared with the chopping method of a bidirectional thyristor, the voltage and current crest factors are smaller, thereby being able to accurately measure the AC signal, and to collect the voltage output by the programmable AC power supply in each power cycle, thereby realizing high-speed collection of AC signals. The collected voltage value is used to calculate the voltage value of the AC wave required to generate the next power cycle, and is applied to subsequent heating control, so that measurement and control are performed alternately, and the temperature changes of the heater can be quickly responded to, thereby improving the control accuracy and stability of the heating system of the large cavity press.

[0072] In one embodiment of the present invention, a heating control system for a large cavity press is provided. Figure 3 As shown, the heating control system 300 of the large cavity press includes: a heating control device 301, a programmable AC power supply 302, a multimeter 303, a transformer 304 and a heater 305. The heater 305 is set in the large cavity press ( Figure 3 heating control device 301 are connected to the programmable AC power supply 302 and the multimeter 303, the programmable AC power supply 302 is connected to the transformer 304, and the transformer 304 is connected to the heater 305.

[0073] The heating control device 301 is used to calculate the sub-target values ​​corresponding to different temperature rise time intervals according to the set target value to be adjusted and the temperature rise time; send control instructions to the programmable AC power supply 302, and send measurement instructions to the multimeter 303; wherein the control instructions are used to indicate the power cycle of the programmable AC power supply 302 and the frequency of the AC wave generated within the power cycle; the measurement instructions are used to indicate the data acquisition cycle and data acquisition frequency of the multimeter 303; the power cycle is the same as the data acquisition cycle; the target value to be adjusted is a target power value, a target voltage value or a target temperature value.

[0074] Before performing heating control, the user can set the target value to be adjusted and the temperature rise time in the heating control device 301. Then, during the heating control process, the heating control device 301 can calculate the sub-target values ​​corresponding to different temperature rise time intervals according to the set target value to be adjusted and the temperature rise time.

[0075] The target value to be adjusted is the target value that needs to be reached when the large cavity press produces the required high temperature conditions. The target value can be the target temperature value or target power value that the heater needs to reach when the large cavity press produces the required high temperature conditions, or it can be the target voltage value output by the programmable AC power supply when the large cavity press produces the required high temperature conditions. When the target value to be adjusted is the target temperature value, the control mode of the corresponding heating control system is the constant temperature control mode. When the target value to be adjusted is the target power value, the control mode of the corresponding heating control system is the constant power control mode. When the target value to be adjusted is the target voltage value, the control mode of the corresponding heating control system is the constant voltage control mode.

[0076] In one example, a temperature-power relationship curve can be fitted according to the temperature and power data of the heater to obtain the corresponding relationship between temperature and power, and then the target power value corresponding to the target temperature value that the heater needs to reach can be determined according to the corresponding relationship. And the target voltage value is determined according to the voltage value that the programmable AC power supply needs to output when the heater reaches the target temperature value. Exemplarily, the high temperature conditions required for the large cavity press can be, for example, high temperature conditions of 2000°C or above.

[0077] The temperature rise time is the time it takes for the large cavity press to produce the required high temperature conditions. The time can be set as needed, for example, it can be set to 1 minute, 10 minutes, etc. Further, the temperature rise time can be divided into time intervals or not. Exemplarily, when dividing the temperature rise time into time intervals, the temperature rise time can be divided into a plurality of time intervals with equal time intervals to obtain different temperature rise time intervals. For example, if the temperature rise time is 1 minute and the time interval is 1 second, the temperature rise time is divided into 60 temperature rise time intervals, and the time length corresponding to each temperature rise time interval is 1 second.

[0078] The target value to be adjusted is evenly divided into different temperature rise time intervals, that is, the sub-target values ​​corresponding to the different temperature rise time intervals are obtained. For example, the target value to be adjusted is the target voltage value represented by V target , the temperature rise time is t seconds, and the time corresponding to the temperature rise time interval is 1 second. Then the sub-target voltage value of the temperature rise time interval corresponding to the i-th second is V i =V i-1 +V target / t,V i-1 is the sub-target voltage value of the temperature rise time interval corresponding to the i-1 second. If the target value to be adjusted is the target voltage value, it is expressed as V target , the temperature rise time is t seconds, and if the temperature rise time is not divided into time intervals, the sub-target voltage value of the temperature rise time interval (t seconds) is V'=V target, where i is an integer greater than 1.

[0079] The programmable AC power supply 302 is used to receive the control instruction sent by the heating control device 301, and generate a corresponding AC voltage according to the power cycle contained in the control instruction and the frequency of the AC wave generated in the power cycle, and apply the generated AC voltage to the primary side of the transformer 304. In an example, the power cycle can be set to 100ms-2.5ms (milliseconds), and the frequency of the AC wave generated in the corresponding power cycle can be set to 10Hz-40Hz (hertz). Exemplarily, the power cycle is 20ms, and the frequency of the AC wave generated in the power cycle is 50Hz, so that the programmable AC power supply 302 generates an AC voltage corresponding to the 50Hz AC wave in the power cycle of 20ms, and applies the generated AC voltage to the primary side of the transformer 304.

[0080] In one example, the programmable AC power supply 302 may use an IT-7803 programmable AC power supply with high voltage regulation accuracy, whose load regulation rate is less than 0.05%+0.05%FS (Full Scall), capable of generating high-precision, high-power AC waveforms, and thus controlling output voltage and current with higher accuracy.

[0081] In one possible implementation, the AC wave generated by the programmable AC power supply 302 may include: a sinusoidal AC wave, a triangular wave, or other complex AC waveforms, so that the output voltage effective value of the programmable AC power supply 302 can be increased by adjusting the amplitude of the AC wave generated by the programmable AC power supply 302 using multiple waveforms.

[0082] Taking a sinusoidal AC wave as an example, when a full sinusoidal cycle waveform is output, the crest factor of the sine wave is 1.414. Conventional instruments can accurately measure the effective values ​​of voltage and current, thus achieving accurate measurement of AC signals.

[0083] The transformer 304 is used to reduce the voltage and increase the current of the AC voltage according to the set gear, and apply the regulated voltage to both ends of the heater 305 to heat the heater 305.

[0084] In order to adapt to the resistance characteristics of different heaters, the transformer 304 is a transformer with different gears, for example, the transformer 304 can include different voltage gears such as 5, 10, 20, 50 and 100V (volts). Exemplarily, the effective value range of the output voltage of the programmable AC power supply 302 can be 0-350V, and the effective value range of the voltage after voltage regulation by the transformer 304 can be 0-5V, etc.

[0085] For the heating control system, the gear of the transformer 304 can be pre-set as needed, such as setting it to 5V gear, 10V gear, etc.

[0086] In one possible implementation, the heater 305 is a resistive load of a conductor or semiconductor material, the conductor material includes: graphite and rhenium sheets, the semiconductor material includes: lanthanum chromate, boron-doped diamond, titanium diboride and titanium carbide, etc., so that the heating control system can stably control different types of heaters.

[0087] The multimeter 303 is used to receive the measurement instruction sent by the heating control device 301, collect the voltage output by the programmable AC power supply 302 in the current power cycle according to the data collection frequency to obtain the primary side voltage value, and send the primary side voltage value to the heating control device 301. The measurement instruction includes the data collection cycle and the data collection frequency. The power cycle is set to be the same as the data collection cycle, so as to collect the output voltage of the programmable AC power supply 302 in each power cycle to avoid data collection confusion.

[0088] In one example, the multimeter 303 may use a multimeter with six and a half digit precision, such as a DMM6500 multimeter, which has high measurement precision. The range and reading of the multimeter may also be pre-adjusted.

[0089] Exemplarily, the data collection cycle is the same as the power cycle, which is 20 ms. The data collection frequency is set to collect a preset number of readings per data collection cycle. The preset number can be set according to actual conditions, such as 128 or 256.

[0090] In a possible implementation, the multimeter 303 for measuring and collecting the output voltage of the programmable AC power supply 302 is specifically used to collect the voltage output by the programmable AC power supply 302 according to the data collection frequency during the current power cycle, and calculate the effective value of the collected voltage to obtain the primary side voltage value.

[0091] The effective value may be the standard deviation or maximum value of the voltage data collected in the current power cycle. For example, the multimeter 303 collects 256 voltage values ​​at a data collection frequency (collecting 256 readings in each data collection cycle) within 20 ms of the current power cycle, calculates and uses the standard deviation of the 256 collected voltage values, or uses the maximum value of the 256 collected voltage values ​​as the effective value, to obtain the primary side voltage value.

[0092] The heating control device 301 is also used to receive the primary side voltage value sent by the multimeter 303, calculate the voltage value of the AC wave required to generate the next power supply cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power supply cycle, and send a control instruction containing the voltage value of the AC wave required to generate the next power supply cycle to the programmable AC power supply 302 for subsequent heating control.

[0093] After calculating the voltage value of the AC wave required to generate the next power cycle, the heating control device 301 sends a control instruction containing the voltage value of the AC wave required to generate the next power cycle to the programmable AC power supply 302, and then the programmable AC power supply 302 generates a corresponding AC voltage in the next power cycle, and applies the AC voltage to the primary side of the transformer 304 to perform subsequent heating control until the heating control time reaches the set temperature rise time, or the parameter of the controlled object reaches the target value to be adjusted.

[0094] The embodiment of the present invention utilizes the high voltage regulation accuracy of the programmable AC power supply, can control the power supply output voltage and current with higher accuracy, and utilizes the full cycle of the AC wave for output. Compared with the chopping method of the bidirectional thyristor, the crest factor of the voltage and current is smaller, so that the AC signal can be accurately measured, and the voltage output by the programmable AC power supply in each power cycle is collected, thereby realizing high-speed collection of AC signals. The collected voltage value is used to calculate the voltage value of the AC wave required to generate the next power cycle, and is applied to the subsequent heating control, so that measurement and control are performed alternately, and the temperature change of the heater can be quickly responded to, thereby improving the control accuracy and stability of the heating system of the large cavity press.

[0095] In a possible implementation, when the target value to be adjusted is a target voltage value, the control mode of the corresponding heating control system is a constant voltage control mode. At this time, the heating control device 301 is specifically used to calculate the sub-target voltage values ​​corresponding to different temperature rise time intervals according to the set target voltage value and temperature rise time.

[0096] In the case where the target value to be adjusted is a target voltage value, the target value to be adjusted is a target voltage value output by the programmable AC power supply 302 when the large cavity press produces the required high temperature conditions. For example, the target voltage value is V target , the temperature rise time is t seconds, and the time corresponding to the temperature rise time interval is 1 second. Then the sub-target voltage value of the temperature rise time interval corresponding to the i-th second is V i =V i-1 +V target / t.

[0097] When the heating control device 301 receives the primary side voltage value sent by the multimeter 303, it is specifically used to calculate the voltage value of the AC wave required to generate the next power cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power cycle using the following expression:

[0098]

[0099] in, The voltage value of the AC wave required to generate the next power cycle, is the sub-target voltage value output by the programmable AC power supply 302 during the temperature rise time interval corresponding to the current power cycle, is the primary side voltage value, and n is the setting parameter.

[0100] For example, if the power cycle is 20ms and the duration of the temperature rise time interval is 1 second, the temperature rise time interval corresponding to the current power cycle can be determined first, and then the sub-target voltage value output by the programmable AC power supply 302 in the temperature rise time interval is determined as the sub-target voltage value output by the programmable AC power supply 302 corresponding to the current power cycle. n is a preset parameter and can be set to an integer between 2 and 8. The smaller the value of n, the larger the control increment of the heating control system. Conversely, the larger the value of n, the smaller the temperature control increment of the heating control system.

[0101] The embodiments of the present invention realize heating control of a large cavity press in a constant pressure control mode.

[0102] In a possible implementation, when the target value to be adjusted is a target power value, the control mode of the corresponding heating control system is a constant power control mode. At this time, the heating control device 301 is specifically used to calculate the sub-target power values ​​corresponding to different temperature rise time intervals according to the set target power value and temperature rise time.

[0103] In the case where the target value to be adjusted is the target power value, the target value to be adjusted is the target power value that the heater 305 needs to reach when the large cavity press produces the required high temperature condition. Since the transformer 304 is connected to the heater 305 and applies the regulated voltage to both ends of the heater 305 to heat the heater 305, the target power value that the heater 305 needs to reach when the large cavity press produces the required high temperature condition is also the target power value output by the transformer 304. For example, the target power value is P target , the temperature rise time is t seconds, and the time corresponding to the temperature rise time interval is 1 second. Then the sub-target power value of the temperature rise time interval corresponding to the i-th second is P i =P i-1 +P target / t,P i-1 is the sub-target power value of the temperature rise time interval corresponding to the i-1th second.

[0104] In this case, the multimeter is multiple, such as Figure 4As shown, one of the multimeters is used to measure and collect the output voltage of the programmable AC power supply 302; one multimeter is used to measure and collect the output voltage and current of the transformer 304. At this time, the multimeter 303 is used to collect the voltage output by the transformer 304 in the current power cycle according to the data collection frequency to obtain the secondary side voltage value, and collect the current output by the transformer 304 in the current power cycle to obtain the secondary side current value, and send the secondary side voltage value and the secondary side current value to the heating control device 301.

[0105] In the embodiment of the present invention, each multimeter 303 can use a multimeter with six-and-a-half-digit precision, and the range and reading of each multimeter are pre-adjusted.

[0106] In a possible implementation, the multimeter 303 for measuring and collecting the output voltage and current of the transformer 304 is specifically used to: collect the voltage output by the transformer 304 according to the data collection frequency during the current power supply cycle, and calculate the effective value of the collected voltage to obtain the secondary side voltage value; collect the current output by the transformer 304 according to the data collection frequency during the current power supply cycle, and calculate the effective value of the collected current to obtain the secondary side current value.

[0107] The effective value may be a standard deviation or a maximum value of the voltage / current data collected in the current power cycle.

[0108] Accordingly, when the heating control device 301 receives the primary side voltage value sent by the multimeter 303 for measuring and collecting the output voltage of the programmable AC power supply 302, and the secondary side voltage value and secondary side current value sent by the multimeter 303 for measuring and collecting the output voltage and current of the transformer 304, it is specifically used to calculate the voltage value of the AC wave required to generate the next power supply cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power supply cycle using the following expression:

[0109]

[0110] in, is the voltage value of the AC wave required to be generated in the next power cycle, P is the sub-target power value output by the transformer 304 in the temperature rise time interval corresponding to the current power cycle, is the secondary side voltage value, is the secondary current value, is the primary side voltage value, and n is the setting parameter.

[0111] The embodiment of the present invention realizes the heating control of a large cavity press in constant power control mode. Experimental data show that in constant power control mode, the actual power value fluctuates between the set target power value and ±0.2W, which improves the control accuracy of the heating system compared to the power fluctuation of ±1-2W in the related art. And under the condition that the properties of the heater are stable, the temperature fluctuation corresponding to the constant power control mode does not exceed ±2℃.

[0112] In a possible implementation, when the target value to be adjusted is a target temperature value, the control mode of the corresponding heating control system is a constant temperature control mode. In this control mode, the target power value corresponding to the target temperature value can be determined according to the preset correspondence between temperature and power. At this time, the heating control device 301 is specifically used to calculate the sub-target power values ​​corresponding to different temperature rise time intervals according to the target power value corresponding to the target temperature value and the temperature rise time, and then switch the constant temperature control mode to the constant power control mode.

[0113] In the case where the target value to be adjusted is the target temperature value that the heater 305 needs to reach when the large cavity press produces the required high temperature conditions, the target power value corresponding to the target temperature value that the heater 305 needs to reach can be determined based on the preset correspondence between temperature and power. Since the transformer 304 is connected to the heater 305 and the regulated voltage is applied to both ends of the heater 305 to heat the heater 305, the target power value that the heater 305 needs to reach is also the target power value output by the transformer 304. Further, based on the target power value and the temperature rise time, the sub-target power values ​​corresponding to different temperature rise time intervals are calculated. For example, the target power value is P target , the temperature rise time is t seconds, and the time corresponding to the temperature rise time interval is 1 second. Then the sub-target power value of the temperature rise time interval corresponding to the i-th second is P i =P i-1 +P target / t,P i-1 is the sub-target power value of the temperature rise time interval corresponding to the i-1th second.

[0114] In the case where the target value to be adjusted is the target temperature value, the sub-target temperature values ​​corresponding to different temperature rise time intervals can also be directly calculated based on the target temperature value and the temperature rise time. Furthermore, based on the preset correspondence between temperature and power, the sub-target power value corresponding to the sub-target temperature value corresponding to each temperature rise time interval can be determined. This is also feasible. For example, the target temperature value is T target , the temperature rise time is t seconds, and the time corresponding to the temperature rise time interval is 1 second. Then the sub-target temperature value of the temperature rise time interval corresponding to the i-th second is T i =Ti-1 +T target / t,T i-1 The sub-target temperature value T of the temperature rise time interval corresponding to the i-1 second is determined according to the preset correspondence between temperature and power. i The corresponding sub-target power value P i .

[0115] In this case, the multimeter is multiple, such as Figure 4 As shown, one of the multimeters is used to measure and collect the output voltage of the programmable AC power supply 302; one multimeter is used to measure and collect the output voltage and current of the transformer 304. At this time, the multimeter 303 is used to collect the voltage output by the transformer 304 in the current power cycle according to the data collection frequency to obtain the secondary side voltage value, and collect the current output by the transformer 304 in the current power cycle to obtain the secondary side current value, and send the secondary side voltage value and the secondary side current value to the heating control device 301.

[0116] In a possible implementation, the multimeter 303 for measuring and collecting the output voltage and current of the transformer 304 is specifically used to: collect the voltage output by the transformer 304 according to the data collection frequency during the current power supply cycle, and calculate the effective value of the collected voltage to obtain the secondary side voltage value; collect the current output by the transformer 304 according to the data collection frequency during the current power supply cycle, and calculate the effective value of the collected current to obtain the secondary side current value.

[0117] Accordingly, when the heating control device 301 receives the primary side voltage value sent by the multimeter 303 for measuring and collecting the output voltage of the programmable AC power supply 302, and the secondary side voltage value and secondary side current value sent by the multimeter 303 for measuring and collecting the output voltage and current of the transformer 304, it is specifically used to calculate the voltage value of the AC wave required to generate the next power supply cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power supply cycle using the following expression:

[0118]

[0119] in, is the voltage value of the AC wave required to be generated in the next power cycle, P is the sub-target power value output by the transformer 304 in the temperature rise time interval corresponding to the current power cycle, is the secondary side voltage value, is the secondary current value, is the primary side voltage value, and n is the setting parameter.

[0120] The embodiment of the present invention realizes the heating control of the large cavity press in the constant temperature control mode. Experimental data shows that in the constant temperature control mode, the corresponding temperature fluctuation does not exceed ±1°C, and the control accuracy of the heating system is relatively high.

[0121] In a possible implementation, Figure 4 As shown, the heating control system 300 may also include a thermocouple 306, which is built into the center of the cavity of the heater 305. A multimeter is connected to both ends of the thermocouple 306 to measure and collect the thermoelectromotive force generated by the thermocouple 306. Accordingly, the multimeter 303 for measuring and collecting the thermoelectromotive force generated by the thermocouple 306 is specifically used to measure and collect the thermoelectromotive force generated by the thermocouple 306 in the current power cycle, and send the thermoelectromotive force to the heating control device 301.

[0122] Exemplarily, the multimeter 303 for measuring and collecting the thermoelectromotive force generated by the thermocouple 306 collects the thermoelectromotive force generated by the thermocouple 306 at the data collection frequency during the current power cycle, and sends the effective value of the collected thermoelectromotive force to the heating control device 301 .

[0123] The thermoelectromotive force generated by the thermocouple in each power cycle is measured and collected. According to the preset correspondence between the thermoelectromotive force and the temperature, the temperature value generated by the thermocouple in each power cycle (that is, the temperature value generated by the heater) is determined, so that the heating control system can better perform heating control.

[0124] In a possible implementation, the heating control device 301 may include an interactive display module and a command control module, wherein the command control module is used to receive the thermoelectromotive force sent by the multimeter 303 for measuring and collecting the thermoelectromotive force generated by the thermocouple 306, and determine the temperature value corresponding to the thermoelectromotive force according to the preset correspondence between the thermoelectromotive force and the temperature.

[0125] Furthermore, the interactive display module is used to display at least one of the following: the target value to be adjusted, the temperature rise time, the sub-target values ​​corresponding to different temperature rise time intervals, the primary side voltage value, the secondary side voltage value, the secondary side current value sent by the multimeter in each power supply cycle, and the temperature value determined according to the thermoelectromotive force sent by the multimeter.

[0126] Exemplarily, in the constant voltage control mode, the interactive display module can display at least one of the following: the target voltage value, the temperature rise time, the sub-target voltage values ​​corresponding to different temperature rise time intervals, the primary side voltage value sent by the multimeter used to measure and collect the output voltage of the programmable AC power supply in each power cycle, and the thermoelectromotive force and its corresponding temperature value sent by the multimeter used to measure and collect the thermoelectromotive force generated by the thermocouple.

[0127] In the constant power control mode, the interactive display module can display at least one of the following: target power value, temperature rise time, sub-target power values ​​corresponding to different temperature rise time intervals, the primary voltage value sent by the multimeter used to measure and collect the output voltage of the programmable AC power supply in each power supply cycle, the secondary voltage value and secondary current value sent by the multimeter used to measure and collect the output voltage and current of the transformer, and the thermoelectromotive force and its corresponding temperature value sent by the multimeter used to measure and collect the thermoelectromotive force generated by the thermocouple.

[0128] In the constant temperature control mode, the interactive display module can display at least one of the following: the target temperature value, the target power value corresponding to the target temperature value, the temperature rise time, the sub-target temperature values ​​and sub-target power values ​​corresponding to different temperature rise time intervals, the primary voltage value sent by the multimeter used to measure and collect the output voltage of the programmable AC power supply in each power supply cycle, the secondary voltage value and secondary current value sent by the multimeter used to measure and collect the output voltage and current of the transformer, and the thermoelectromotive force and its corresponding temperature value sent by the multimeter used to measure and collect the thermoelectromotive force generated by the thermocouple.

[0129] The multimeter is used to collect data such as the output voltage of the programmable AC power supply, the output voltage and current of the transformer, and the thermoelectric electromotive force of the thermocouple in each power cycle, realizing high-speed acquisition of AC signals, so as to use the collected data to calculate the voltage value of the AC wave required to generate the next power cycle, and apply it to the subsequent heating control, so that measurement and control are carried out alternately, which can quickly respond to the temperature change of the heater, so that the temperature control speed is high and the deviation is small, which can effectively prevent the problem of heater power fluctuation instability caused by excessive adjustment, and improve the control accuracy and stability of the heating system of the large cavity press. The interactive display module is used to display the voltage, power, temperature and other data in the temperature control process, and the corresponding correlation curve can also be drawn to better realize the heating control of the heating control system.

[0130] For example, the connection relationship between the components of the heating control system of the large cavity press provided by the embodiment of the present invention is as follows: Figure 5 As shown. The Labview algorithm program deployed in the heating control device calculates the sub-target values ​​corresponding to different temperature rise time intervals according to the set target value to be adjusted and the temperature rise time, and sends control instructions to the programmable AC power supply and measurement instructions to the multimeter ( Figure 5 The control instruction is used to indicate the power cycle of the programmable AC power supply and the frequency of the AC wave generated in the power cycle, and the measurement instruction is used to indicate the data acquisition cycle and data acquisition frequency of each multimeter; the power cycle is the same as the data acquisition cycle; the target value to be adjusted is the target power value, the target voltage value or the target temperature value.

[0131] After starting the heating control, the programmable AC power supply generates the corresponding AC voltage according to the control instruction, and applies the AC voltage to the primary side of the transformer. The transformer adjusts the AC voltage according to the set gear, and applies the adjusted voltage to both ends of the heater to heat the heater. In each power cycle, multimeter 1 collects the voltage output by the programmable AC power supply in the current power cycle according to the data acquisition frequency to obtain the primary side voltage value, and sends the primary side voltage value to the heating control device; multimeter 2 collects the voltage output by the transformer in the current power cycle according to the data acquisition frequency to obtain the secondary side voltage value, and collects the current output by the transformer in the current power cycle to obtain the secondary side current value, and sends the secondary side voltage value and the secondary side current value to the heating control device; multimeter 3 collects the thermoelectric electromotive force generated by the thermocouple in the current power cycle according to the data acquisition frequency, and sends the thermoelectric electromotive force to the heating control device.

[0132] The heating control device receives the data sent by each multimeter, calculates the voltage value of the AC wave required to generate the next power cycle based on the received data and the sub-target value of the temperature rise time interval corresponding to the current power cycle, and sends a control instruction containing the voltage value of the AC wave required to generate the next power cycle to the programmable AC power supply. The programmable AC power supply then generates a corresponding AC voltage according to the control instruction, and applies the AC voltage to the primary side of the transformer for subsequent heating control.

[0133] The embodiment of the present invention utilizes the high voltage regulation accuracy of the programmable AC power supply, can control the power supply output voltage and current with higher accuracy, and utilizes the full cycle of the AC wave for output. Compared with the chopping method of the bidirectional thyristor, the crest factor of the voltage and current is smaller, so that the AC signal can be accurately measured, and the voltage output by the programmable AC power supply, the voltage and current output by the transformer, and the thermoelectromotive force of the thermocouple in each power cycle are collected, thereby realizing high-speed collection of AC signals, and the collected data is used to calculate the voltage value of the AC wave required to generate the next power cycle, and applied to the subsequent heating control, so that measurement and control are performed alternately, and the temperature change of the heater can be quickly responded to, so that the temperature control speed is high and the deviation is small, and the problem of heater power fluctuation instability caused by excessive adjustment amount can be effectively prevented, thereby improving the control accuracy and stability of the heating system of the large cavity press.

[0134] The embodiment of the present invention also provides a heating control method for a large cavity press, such as Figure 6 As shown, the heating control system applied to the above-mentioned large cavity press comprises:

[0135] S601, the heating control device calculates sub-target values ​​corresponding to different temperature rise time intervals according to the set target value to be adjusted and the temperature rise time.

[0136] The target value to be adjusted is a target power value, a target voltage value or a target temperature value.

[0137] S602, the heating control device sends a control instruction to the programmable AC power supply and sends a measurement instruction to the multimeter.

[0138] The control instruction is used to indicate the power cycle of the programmable AC power supply and the frequency of the AC wave generated in the power cycle. The measurement instruction is used to indicate the data acquisition cycle and data acquisition frequency of the multimeter. The power cycle is the same as the data acquisition cycle.

[0139] S603, the programmable AC power supply receives the control instruction, generates a corresponding AC voltage according to a power cycle and the frequency of the AC wave generated in the power cycle, and applies the AC voltage to the primary side of the transformer.

[0140] S604, the transformer regulates the AC voltage according to the set gear, and applies the regulated voltage to both ends of the heater to heat the heater.

[0141] S605, the multimeter receives the measurement instruction, and collects the voltage output by the programmable AC power supply in the current power cycle according to the data collection frequency to obtain a primary side voltage value, and sends the primary side voltage value to the heating control device.

[0142] S606, the heating control device receives the primary side voltage value, calculates the voltage value of the AC wave required to generate the next power cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power cycle, and sends a control instruction containing the voltage value of the AC wave required to generate the next power cycle to the programmable AC power supply, returns to execute the programmable AC power supply to receive the control instruction, and generates a corresponding AC wave within the power cycle, and sends the electrical signal corresponding to the AC wave to the transformer, and performs subsequent heating control.

[0143] In the embodiment of the present invention, the high voltage regulation accuracy of the programmable AC power supply is utilized, and the power supply output voltage and current can be controlled with higher accuracy. The full cycle of the AC wave is used for output. Compared with the chopping method of the bidirectional thyristor, the crest factor of the voltage and current is smaller, so that the AC signal can be accurately measured, and the voltage output by the programmable AC power supply in each power cycle is collected, thereby realizing high-speed collection of AC signals. The collected voltage value is used to calculate the voltage value of the AC wave required to generate the next power cycle, and it is applied to the subsequent heating control, so that measurement and control are performed alternately, and the temperature change of the heater can be quickly responded to, thereby improving the control accuracy and stability of the heating system of the large cavity press.

[0144] In a possible implementation, when the target value to be adjusted is a target voltage value, the heating control device calculates sub-target values ​​corresponding to different temperature rise time intervals according to the set target value to be adjusted and the temperature rise time, including: calculating sub-target voltage values ​​corresponding to different temperature rise time intervals according to the set target voltage value and the temperature rise time;

[0145] The heating control device calculates the voltage value of the AC wave required to be generated in the next power cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power cycle, including:

[0146] The following expression is used to calculate the voltage value of the AC wave required to generate the next power cycle based on the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power cycle:

[0147]

[0148] in, The voltage value of the AC wave required to generate the next power cycle, The sub-target voltage value of the programmable AC power output in the temperature rise time interval corresponding to the current power cycle, is the primary side voltage value, and n is the setting parameter.

[0149] In a possible implementation, when the target value to be adjusted is a target power value, there are multiple multimeters, and the heating control device calculates sub-target values ​​corresponding to different temperature rise time intervals according to the set target value to be adjusted and the temperature rise time, including: calculating the sub-target power values ​​corresponding to different temperature rise time intervals according to the set target power value and the temperature rise time;

[0150] The method further includes: the multimeter collects the voltage output by the transformer in the current power cycle according to the data collection frequency to obtain the secondary side voltage value, and collects the current output by the transformer in the current power cycle to obtain the secondary side current value, and sends the secondary side voltage value and the secondary side current value to the heating control device;

[0151] The heating control device calculates the voltage value of the AC wave required to be generated in the next power cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power cycle, including:

[0152] The following expression is used to calculate the voltage value of the AC wave required to generate the next power cycle based on the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power cycle:

[0153]

[0154] in, is the voltage value of the AC wave required to be generated in the next power cycle, P is the sub-target power value of the transformer output in the temperature rise time interval corresponding to the current power cycle, is the secondary side voltage value, is the secondary current value, is the primary side voltage value, and n is the setting parameter.

[0155] In a possible implementation manner, when the target value to be adjusted is a target temperature value, there are multiple multimeters, and the method further includes: determining a target power value corresponding to the target temperature value according to a preset correspondence relationship between temperature and power;

[0156] The heating control device calculates sub-target values ​​corresponding to different temperature rise time intervals according to the set target value to be adjusted and the temperature rise time, including: calculating sub-target power values ​​corresponding to different temperature rise time intervals according to the target power value corresponding to the target temperature value and the temperature rise time;

[0157] The method further includes: the multimeter collects the voltage output by the transformer in the current power cycle according to the data collection frequency to obtain the secondary side voltage value, and collects the current output by the transformer in the current power cycle to obtain the secondary side current value, and sends the secondary side voltage value and the secondary side current value to the heating control device;

[0158] The heating control device calculates the voltage value of the AC wave required to be generated in the next power cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power cycle, including:

[0159] The following expression is used to calculate the voltage value of the AC wave required to generate the next power cycle based on the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power cycle:

[0160]

[0161] in, is the voltage value of the AC wave required to be generated in the next power cycle, P is the sub-target power value of the transformer output in the temperature rise time interval corresponding to the current power cycle, is the secondary side voltage value, is the secondary current value, is the primary side voltage value, and n is the setting parameter.

[0162] In a possible implementation, the multimeter collects the voltage output by the programmable AC power supply in the current power cycle according to the data collection frequency to obtain the primary side voltage value, including: collecting the voltage output by the programmable AC power supply according to the data collection frequency in the current power cycle, and calculating the effective value of the collected voltage to obtain the primary side voltage value;

[0163] The multimeter collects the voltage output by the transformer in the current power cycle according to the data collection frequency to obtain the secondary side voltage value, including: collecting the voltage output by the transformer according to the data collection frequency in the current power cycle, and calculating the effective value of the collected voltage to obtain the secondary side voltage value;

[0164] The multimeter collects the current output by the transformer in the current power cycle according to the data collection frequency to obtain the secondary current value, including: collecting the current output by the transformer according to the data collection frequency in the current power cycle, and calculating the effective value of the collected current to obtain the secondary current value.

[0165] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0166] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0167] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A heating control system for a large cavity press, characterized in that: The heating control system comprises: a heating control device, a programmable AC power supply, a multimeter, a transformer and a heater; the heater is a resistive load arranged in the pressure transmission medium of the large cavity press; The heating control device is used to calculate the sub-target values ​​corresponding to different temperature rise time intervals according to the set target value to be adjusted and the temperature rise time; send a control instruction to the programmable AC power supply, and send a measurement instruction to the multimeter; the control instruction is used to indicate the power cycle of the programmable AC power supply and the frequency of the AC wave generated in the power cycle; the measurement instruction is used to indicate the data acquisition cycle and data acquisition frequency of the multimeter; the power cycle is the same as the data acquisition cycle; The programmable AC power supply is used to receive the control instruction, generate a corresponding AC voltage according to the power cycle and the frequency of the AC wave generated in the power cycle, and apply the AC voltage to the primary side of the transformer; The transformer is used to adjust the AC voltage according to a set gear, and apply the adjusted voltage to both ends of the heater to heat the heater; The multimeter is used to receive the measurement instruction, collect the voltage output by the programmable AC power supply in the current power cycle according to the data collection frequency to obtain a primary side voltage value, and send the primary side voltage value to the heating control device; The heating control device is further used to receive the primary side voltage value, calculate the voltage value of the AC wave required to be generated in the next power cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power cycle, and send a control instruction containing the voltage value of the AC wave required to be generated in the next power cycle to the programmable AC power supply to perform subsequent heating control; Wherein, when the target value to be adjusted is a target voltage value, the heating control device is specifically used to calculate the sub-target voltage values ​​corresponding to different temperature rise time intervals according to the set target voltage value and the temperature rise time; and, according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power supply cycle, the voltage value of the AC wave required to be generated in the next power supply cycle is calculated using the following expression: ； in, The voltage value of the AC wave required to generate the next power cycle, is the sub-target voltage value output by the programmable AC power supply in the temperature rise time interval corresponding to the current power cycle, is the primary side voltage value, and n is a setting parameter.

2. The heating control system according to claim 1, characterized in that: The target value to be adjusted may also be a target power value. In the case where the target value to be adjusted is a target power value, there are multiple multimeters, and the heating control device is specifically used to calculate sub-target power values ​​corresponding to different temperature rise time intervals according to the set target power value and temperature rise time. The multimeter is used to collect the voltage output by the transformer in the current power cycle according to the data collection frequency to obtain the secondary side voltage value, and collect the current output by the transformer in the current power cycle to obtain the secondary side current value, and send the secondary side voltage value and the secondary side current value to the heating control device; The heating control device is specifically used to calculate the voltage value of the AC wave required to be generated in the next power cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power cycle using the following expression: ； in, is the voltage value of the AC wave required to be generated in the next power cycle, P is the sub-target power value output by the transformer in the temperature rise time interval corresponding to the current power cycle, is the secondary side voltage value, is the secondary side current value, is the primary side voltage value, and n is a setting parameter.

3. The heating control system according to claim 1, characterized in that: The target value to be adjusted may also be a target temperature value. When the target value to be adjusted is a target temperature value, there are multiple multimeters. The target power value corresponding to the target temperature value is determined according to a preset correspondence between temperature and power. The heating control device is specifically used to calculate sub-target power values ​​corresponding to different temperature rise time intervals according to the target power value corresponding to the target temperature value and the temperature rise time. The multimeter is used to collect the voltage output by the transformer in the current power cycle according to the data collection frequency to obtain the secondary side voltage value, and collect the current output by the transformer in the current power cycle to obtain the secondary side current value, and send the secondary side voltage value and the secondary side current value to the heating control device; The heating control device is specifically used to calculate the voltage value of the AC wave required to be generated in the next power cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power cycle using the following expression: ； in, is the voltage value of the AC wave required to be generated in the next power cycle, P is the sub-target power value output by the transformer in the temperature rise time interval corresponding to the current power cycle, is the secondary side voltage value, is the secondary side current value, is the primary side voltage value, and n is a setting parameter.

4. The heating control system according to claim 3, characterized in that: The multimeter is specifically used for: Collecting the voltage output by the programmable AC power supply at the data collection frequency during the current power cycle, and calculating the effective value of the collected voltage to obtain a primary side voltage value; Collecting the voltage output by the transformer at the data collection frequency during the current power supply cycle, and calculating the effective value of the collected voltage to obtain a secondary side voltage value; The current output by the transformer is collected according to the data collection frequency during the current power supply cycle, and the effective value of the collected current is calculated to obtain the secondary side current value.

5. The heating control system according to claim 1, characterized in that: The heater is a resistive load of a conductor or semiconductor material. The conductor material includes graphite and rhenium sheets. The semiconductor material includes lanthanum chromate, boron-doped diamond, titanium diboride and titanium carbide.

6. The heating control system according to any one of claims 2 to 4, characterized in that: The heating control system further includes: a thermocouple, the thermocouple being built into the center of the cavity of the heater; The multimeter is also used to measure and collect the thermoelectromotive force generated by the thermocouple in the current power supply cycle, and send the thermoelectromotive force to the heating control device.

7. The heating control system according to claim 6, characterized in that: The heating control device includes an interactive display module and a command control module; The command control module is used to receive the thermoelectromotive force and determine the temperature value corresponding to the thermoelectromotive force according to a preset corresponding relationship between the thermoelectromotive force and the temperature; The interactive display module is used to display at least one of the following: the target value to be adjusted, the temperature rise time, the sub-target values ​​corresponding to the different temperature rise time intervals, the primary side voltage value, the secondary side voltage value, the secondary side current value sent by the multimeter in each power supply cycle, and the temperature value determined according to the thermoelectromotive force sent by the multimeter.

8. The heating control system according to claim 1, characterized in that: The AC wave includes a sinusoidal AC wave and a triangular wave.

9. A heating control method for a large cavity press, characterized in that: A heating control system applied to a large cavity press as claimed in any one of claims 1 to 8, the method comprising: The heating control device calculates the sub-target values ​​corresponding to different temperature rise time intervals according to the set target value to be adjusted and the temperature rise time; The heating control device sends a control instruction to the programmable AC power supply, and sends a measurement instruction to the multimeter; the control instruction is used to indicate the power cycle of the programmable AC power supply and the frequency of the AC wave generated in the power cycle, and the measurement instruction is used to indicate the data acquisition cycle and data acquisition frequency of the multimeter, and the power cycle is the same as the data acquisition cycle; The programmable AC power supply receives the control instruction, generates a corresponding AC voltage according to the power cycle and the frequency of the AC wave generated in the power cycle, and applies the AC voltage to the primary side of the transformer; The transformer regulates the AC voltage according to the set gear, and applies the regulated voltage to both ends of the heater to heat the heater; The multimeter receives the measurement instruction, and acquires the voltage output by the programmable AC power supply in the current power cycle according to the data acquisition frequency to obtain a primary side voltage value, and sends the primary side voltage value to the heating control device; The heating control device receives the primary side voltage value, calculates the voltage value of the AC wave required to generate the next power supply cycle according to the primary side voltage value and the sub-target value of the temperature rise time interval corresponding to the current power supply cycle, and sends a control instruction containing the voltage value of the AC wave required to generate the next power supply cycle to the programmable AC power supply, returns to execute the step of the programmable AC power supply receiving the control instruction, generating a corresponding AC wave within the power supply cycle, and sending the electrical signal corresponding to the AC wave to the transformer, and performing subsequent heating control.

Images