Induction heating control system and control method

Abstract

The invention relates to the technical field of electric furnace heating control, particularly provides an induction heating control system and method, and aims to solve the technical problems that in the prior art, an analog circuit control mode is poor in anti-jamming capability in an induction heating electric furnace, debugging is complex, and accurate control and intelligent management of the heating process of the electric furnace cannot be achieved. The system comprises a digital-to-analog conversion module used for performing digital-to-analog conversion on analog signals transmitted by an analog signal conditioning circuit to obtain digital quantity signals, the analog signals comprising a power given signal, a direct-current voltage signal, a direct-current current signal, an intermediate-frequency voltage signal and an intermediate-frequency current signal; the low-pass filtering module is used for performing low-pass filtering operation on the signals existing in the digital quantity signal mode; and the calculation module is used for calculating the real-time power, the PWM frequency and the phase information of the electric furnace according to the digital quantity signal filtered by the low-pass filtering module.

Description

Technical Field

[0001] The present invention relates to the technical field of heating control, and in particular to an induction heating control system and a control method. Background Art

[0002] In the field of induction heating technology, the series resonant induction heating furnace is the core equipment, and the performance of its control system is directly related to the stability and safety of the production process. At present, most of these furnaces still use traditional analog circuit control systems, which mainly rely on the method of external excitation followed by self-excitation in terms of control strategy.

[0003] Specifically, the system is first started through external excitation control, and then enters the self-excitation control stage. It automatically adjusts the pulse output by real-time monitoring of the intermediate frequency current and detecting the overcurrent signal to track the system resonant frequency. Although this control strategy is relatively simple to implement, it faces the significant problem of weak anti-interference ability in practical applications. When external factors such as conductive dust and high-power electromagnetic fields in the working environment interfere with the output signal of the intermediate frequency current sensor, the existing self-excitation control method is prone to misjudgment and send out erroneous pulse signals, which in turn causes serious faults such as system circuit short circuit or inverter subversion. These faults will not only cause equipment damage, but may also affect the normal operation of the entire production line, and even cause chain reactions such as high-voltage tripping and transformer burning, causing huge losses to customers.

[0004] In addition, the debugging process of analog circuit control systems is also extremely complex and highly dependent on the experience of technicians. During the debugging process, technicians need to repeatedly adjust the potentiometer to optimize the system parameters, which is not only time-consuming and labor-intensive, but also often difficult to ensure consistency and stability of the debugging results. At the same time, due to the limitations of the analog circuit itself, the system cannot communicate directly with modern industrial control equipment such as programmable logic control and touch screens, resulting in an unfriendly human-computer interaction interface and complex operation, which is difficult to meet the needs of modern industry for informatization and intelligence.

[0005] In view of the harsh environment of induction heating industrial furnaces, such as high conductive dust, strong electromagnetic field interference, high temperature, and high requirements for system reliability, the shortcomings of traditional analog circuit control systems have become increasingly prominent. Therefore, it is particularly important to develop a new induction heating control method and system. Summary of the invention

[0006] The embodiment of the present invention provides an induction heating control system and control method to solve the following technical problems: the analog circuit control mode in the prior art has poor anti-interference ability in an induction heating furnace, is complex to debug, and cannot achieve precise control and intelligent management of the furnace heating process.

[0007] In a first aspect, an embodiment of the present invention provides an induction heating control system, comprising a digital-to-analog conversion module, for performing digital-to-analog conversion on an analog signal transmitted by an analog signal conditioning circuit to obtain a digital quantity signal, wherein the analog signal comprises a power given signal, a DC voltage signal, a DC current signal, an intermediate frequency voltage signal, and an intermediate frequency current signal; A low-pass filter module is connected to the digital-to-analog conversion module and is used to perform a low-pass filter operation on a signal in a digital quantity signal mode; A calculation module is connected to the low-pass filter module and is used to calculate the real-time power, PWM frequency and phase information of the electric furnace according to the digital signal filtered by the low-pass filter module; The PWM frequency determination module is connected to the calculation module and is used to judge and determine the PWM frequency used to control the driving module based on the calculated real-time power, PWM frequency and phase information, and transmit the determined PWM frequency to the driving module.

[0008] In a possible implementation of the embodiment of the present invention, the digital-to-analog conversion module includes: The first digital-to-analog conversion module is used to perform ADC conversion on the power given signal according to a fixed sampling frequency to obtain the power given signal in a digital quantity signal mode; A second digital-to-analog conversion module is used to perform ADC conversion on the DC voltage signal and the DC current signal according to a fixed sampling frequency to obtain the DC voltage signal and the DC current signal in a digital quantity signal mode; The third digital-to-analog conversion module is used to perform ADC conversion on the intermediate frequency voltage signal and the intermediate frequency current signal according to a fixed sampling frequency to obtain the intermediate frequency voltage signal and the intermediate frequency current signal in a digital quantity signal mode.

[0009] In a possible implementation of the embodiment of the present invention, the system further includes: A storage module, connected to the first digital-to-analog conversion module, the second digital-to-analog conversion module and the third digital-to-analog conversion module, respectively, and used to store the power given signal, the DC voltage signal and the DC current signal, and the intermediate frequency voltage signal and the intermediate frequency current signal in the digital signal mode in the corresponding memory array; The display module is connected to the calculation module and is used to display the real-time power, PWM frequency and phase information obtained by the calculation module.

[0010] In a possible implementation of the embodiment of the present invention, the low-pass filtering module specifically includes: A first low-pass filtering module is connected to the first digital-to-analog conversion module and is used to perform low-pass filtering on the power given signal in a digital signal mode obtained by the first digital-to-analog conversion module; A second low-pass filtering module is connected to the second digital-to-analog conversion module and is used to perform low-pass filtering on the DC voltage signal and the DC current signal in the digital quantity signal mode obtained by the second digital-to-analog conversion module; The third low-pass filtering module is connected to the third digital-to-analog conversion module and is used to perform low-pass filtering on the intermediate frequency voltage signal and the intermediate frequency current signal in the digital signal mode obtained by the third digital-to-analog conversion module.

[0011] In a possible implementation of the embodiment of the present invention, the calculation module includes: A real-time power calculation module is connected to the second low-pass filter module and is used to perform multiplication calculation on the DC voltage signal and the DC current signal filtered by the second low-pass filter module to obtain the real-time power of the electric furnace; The Fourier calculation module is connected to the third low-pass filter module and is used to perform Fourier calculation on the intermediate frequency voltage signal and the intermediate frequency current signal after the third low-pass filter processing to obtain the PWM frequency and phase information of the electric furnace.

[0012] In a possible implementation of the embodiment of the present invention, the PWM frequency determination module specifically includes: Discrete PID calculation module, used to perform discrete PID calculation action according to the current communication or potentiometer given power value and the real-time power calculated by the calculation module; The PWM frequency saturation judgment module is connected to the discrete PID calculation module and is used to compare the result calculated and output by the discrete PID calculation module with the PWM frequency and phase information calculated by the calculation module to judge whether the PWM frequency is saturated and limited. When the PWM frequency is determined to be in a saturated state, the PWM frequency calculated and output by the discrete PID calculation module is limited and transmitted to the drive module; when the PWM frequency is determined to be in an unsaturated state, the process ends.

[0013] In a second aspect, an embodiment of the present invention further provides an induction heating control method, comprising: The digital-to-analog conversion module performs digital-to-analog conversion on the analog signal transmitted by the analog signal conditioning circuit to obtain a digital quantity signal, wherein the analog signal includes a power setting signal, a DC voltage signal, a DC current signal, an intermediate frequency voltage signal, and an intermediate frequency current signal; The low-pass filter module performs low-pass filtering operation on the signal in the digital signal mode; The calculation module calculates the real-time power, PWM frequency and phase information of the electric furnace according to the digital signal filtered by the low-pass filter module; The PWM frequency determination module judges and determines the PWM frequency of the control driving module according to the calculated real-time power, PWM frequency and phase information, and transmits the determined PWM frequency to the driving module.

[0014] In a possible implementation of the embodiment of the present invention, the signal conversion method of the digital-to-analog conversion module specifically includes: The first digital-to-analog conversion module performs ADC conversion on the power given signal according to a fixed sampling frequency to obtain the power given signal in a digital quantity signal mode; The second digital-to-analog conversion module performs ADC conversion on the DC voltage signal and the DC current signal according to a fixed sampling frequency to obtain the DC voltage signal and the DC current signal in a digital quantity signal mode; The third digital-to-analog conversion module performs ADC conversion on the intermediate frequency voltage signal and the intermediate frequency current signal according to a fixed sampling frequency to obtain the intermediate frequency voltage signal and the intermediate frequency current signal in a digital quantity signal mode; The low-pass filtering operation method of the low-pass filtering module specifically includes: The first low-pass filtering module performs low-pass filtering on the power given signal in the digital signal mode obtained by the first digital-to-analog conversion module; The second low-pass filtering module performs low-pass filtering on the DC voltage signal and the DC current signal in the digital signal mode obtained by the second digital-to-analog conversion module; The third low-pass filtering module performs low-pass filtering on the intermediate frequency voltage signal and the intermediate frequency current signal in the digital signal mode obtained by the third digital-to-analog conversion module; The calculation method of the calculation module specifically includes: The real-time power calculation module performs multiplication calculation on the DC voltage signal and the DC current signal filtered by the second low-pass filter module to obtain the real-time power of the electric furnace; The Fourier calculation module performs Fourier calculation on the intermediate frequency voltage signal and the intermediate frequency current signal after the third low-pass filtering process to obtain the PWM frequency and phase information of the electric furnace; The determination method of the PWM frequency determination module specifically includes: The discrete PID calculation module performs discrete PID calculation actions according to the current communication or potentiometer given power value and the real-time power calculated by the calculation module; the calculation formula of the discrete PID calculation module is as follows: (1); in, is the output value, is the proportionality coefficient, is the deviation, is the integration coefficient, is the error integral, is the differential coefficient, is the set value, which is 1, 2, ..., , is the system sampling time; in, Proportional coefficient, setting hour, To set a constant value, when When , the proportional coefficient calculation formula is: (2); If you set and are less than or equal to 1, then the proportionality coefficient Less than or equal to 1, so that the heating temperature will not exceed the set temperature, which can effectively avoid the adverse effect of the heating temperature exceeding the set temperature on the heated object during the heating process; The integral coefficient is related to the heating target temperature. Different integral coefficient values ​​are set according to different target temperatures. The integral coefficient calculation formula is: (3); is the ambient temperature value, is a constant set according to the ambient temperature. The higher the ambient temperature, the smaller the value. is the difference between the furnace temperature and the ambient temperature. The higher the furnace temperature, the faster the heat dissipation. The larger the value, the higher the value. Different values ​​can be taken according to different target temperatures. During the temperature adjustment process, the deviation between the actual heating temperature and the target heating temperature is set as the target deviation value. When the actual temperature deviation value is greater than the target deviation value, the differential coefficient is 0 to improve the system response speed. When the actual temperature deviation value is less than the target deviation value, The differential coefficient formula is: (4) At this time, the differential coefficient is large, which improves the anti-interference performance of the system; The PWM frequency saturation judgment module compares the result calculated and output by the discrete PID calculation module with the PWM frequency and phase information calculated by the calculation module to determine whether the PWM frequency is saturated and limited. When the PWM frequency is determined to be in a saturated state, the PWM frequency calculated and output by the discrete PID calculation module is limited and transmitted to the drive module; when the PWM frequency is determined to be in an unsaturated state, the process ends.

[0015] In a possible implementation manner of the embodiment of the present invention, the method further includes: The power given signal, the DC voltage signal and the DC current signal, as well as the intermediate frequency voltage signal and the intermediate frequency current signal in the form of digital signal are stored in the corresponding memory array storage module.

[0016] The real-time power, PWM frequency and phase information obtained by the calculation module are displayed in the display module.

[0017] An induction heating control system and control method provided by the embodiments of the present invention have the following beneficial effects: Through the data conversion module, the analog signal is converted into a digital signal, and the low-pass filter module filters the digital signal, which further improves the purity and accuracy of the signal, effectively improves the system's anti-interference ability, and reduces the occurrence of serious faults such as system circuit short circuit or inverter subversion; these measures significantly enhance the system's anti-interference ability and reduce the risk of serious faults such as system short circuit or inverter subversion caused by external interference, thereby improving the overall stability and reliability of the system.

[0018] Through the calculation module and PWM frequency determination module, accurate control and intelligent management of the electric furnace heating process are achieved. The calculation module can calculate the power, PWM frequency and phase information of the electric furnace in real time according to the filtered digital signal, providing accurate data support for heating control; the PWM frequency determination module judges and determines the PWM frequency used to control the drive module based on these data, realizing accurate regulation of the heating process. This digital and intelligent control method not only improves the heating efficiency and control accuracy, but also simplifies the debugging process, reduces the dependence on the experience of technicians, and meets the needs of modern industry for informatization and intelligence. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 A schematic diagram of an induction heating control system architecture provided by an embodiment of the present invention; Figure 2 A schematic diagram of the specific internal structure of an induction heating control system provided by an embodiment of the present invention; Figure 3 A schematic flow chart of an induction heating control method provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. 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 without making creative work are within the scope of protection of the present invention.

[0021] The technical solution proposed in the embodiment of the present invention is described in detail below with reference to the accompanying drawings.

[0022] Figure 1 A schematic diagram of the architecture of an induction heating control system provided by an embodiment of the present invention.

[0023] like Figure 1 As shown, the induction heating control system provided by the embodiment of the present invention comprises at least a digital-to-analog conversion module for performing digital-to-analog conversion on the analog signal transmitted by the analog signal conditioning circuit to obtain a digital quantity signal, wherein the analog signal comprises a power setting signal, a DC voltage signal, a DC current signal, an intermediate frequency voltage signal and an intermediate frequency current signal. The above-mentioned analog signal conditioning circuit is a common electronic component, and a suitable product can be selected according to application requirements. The power setting signal is usually a target power value set by an external control system or a user as a benchmark for system operation. DC voltage and current signals, which reflect the DC working state of the power supply or load, are important bases for system monitoring and control. The intermediate frequency voltage and current signals come from the output of an intermediate conversion link such as an inverter or rectifier circuit, and are used to monitor the conversion process or as control feedback.

[0024] A low-pass filter module is connected to the digital-to-analog conversion module and is used to perform a low-pass filter operation on a signal in a digital quantity signal mode; A discrete PID calculation module, used for executing discrete PID calculation actions according to the current communication or potentiometer given power value and the real-time power calculated by the calculation module; The PWM frequency determination module is connected to the calculation module and is used to judge and determine the PWM frequency used to control the driving module based on the calculated real-time power, PWM frequency and phase information, and at the same time transmit the determined PWM frequency to the driving module, which converts it into a specific control signal to drive the electric furnace actuator to work.

[0025] Figure 2 A schematic diagram of the specific internal structure of an induction heating control system provided by an embodiment of the present invention.

[0026] like Figure 2 As shown, in one or more embodiments of the present application, the digital-to-analog conversion module of the system specifically includes: The first digital-to-analog conversion module is used to perform ADC conversion on the power given signal according to a fixed sampling frequency to obtain the power given signal in a digital quantity signal mode; A second digital-to-analog conversion module is used to perform ADC conversion on the DC voltage signal and the DC current signal according to a fixed sampling frequency to obtain the DC voltage signal and the DC current signal in a digital quantity signal mode; The third digital-to-analog conversion module is used to perform ADC conversion on the intermediate frequency voltage signal and the intermediate frequency current signal according to a fixed sampling frequency to obtain the intermediate frequency voltage signal and the intermediate frequency current signal in a digital quantity signal mode.

[0027] The low-pass filter module specifically includes: A first low-pass filtering module is connected to the first digital-to-analog conversion module and is used to perform low-pass filtering on the power given signal in a digital signal mode obtained by the first digital-to-analog conversion module; A second low-pass filtering module is connected to the second digital-to-analog conversion module and is used to perform low-pass filtering on the DC voltage signal and the DC current signal in the digital quantity signal mode obtained by the second digital-to-analog conversion module; The third low-pass filtering module is connected to the third digital-to-analog conversion module and is used to perform low-pass filtering on the intermediate frequency voltage signal and the intermediate frequency current signal in the digital signal mode obtained by the third digital-to-analog conversion module.

[0028] Furthermore, the calculation module includes: A real-time power calculation module is connected to the second low-pass filter module and is used to perform multiplication calculation on the DC voltage signal and the DC current signal filtered by the second low-pass filter module to obtain the real-time power of the electric furnace; The Fourier calculation module is connected to the third low-pass filter module and is used to perform Fourier calculation on the intermediate frequency voltage signal and the intermediate frequency current signal after the third low-pass filter processing to obtain the PWM frequency and phase information of the electric furnace.

[0029] The PWM frequency determination module specifically includes: Discrete PID calculation module, used to perform discrete PID calculation action according to the current communication or potentiometer given power value and the real-time power calculated by the calculation module; The PWM frequency saturation judgment module is connected to the discrete PID calculation module and is used to compare the result calculated and output by the discrete PID calculation module with the PWM frequency and phase information calculated by the calculation module to judge whether the PWM frequency is saturated and limited. When the PWM frequency is determined to be in a saturated state, the PWM frequency calculated and output by the discrete PID calculation module is limited and transmitted to the drive module; when the PWM frequency is determined to be in an unsaturated state, the process ends.

[0030] In one or more embodiments of the present application, the system also includes: a storage module, which is respectively connected to the first digital-to-analog conversion module, the second digital-to-analog conversion module and the third digital-to-analog conversion module, and is used to store the power given signal, DC voltage signal and DC current signal in digital signal mode, as well as the intermediate frequency voltage signal and intermediate frequency current signal in the corresponding memory array; a display module, which serves as an interactive interface between the user and the control system, is connected to the calculation module, and is used to display the real-time power, PWM frequency and phase information obtained by the calculation module and obtain the user's operation instructions to realize human-computer interaction.

[0031] Figure 3 A schematic flow chart of an induction heating control method provided by an embodiment of the present invention. Figure 3 As shown, the electric furnace heating control method provided by the embodiment of the present invention at least includes the following execution steps: Step S1, the digital-to-analog conversion module performs digital-to-analog conversion on the analog signal transmitted by the analog signal conditioning circuit to obtain a digital quantity signal, wherein the analog signal includes a power setting signal, a DC voltage signal, a DC current signal, an intermediate frequency voltage signal, and an intermediate frequency current signal; The signal conversion method of the digital-to-analog conversion module specifically includes: The first digital-to-analog conversion module performs ADC conversion on the power given signal according to a fixed sampling frequency to obtain the power given signal in a digital quantity signal mode; The second digital-to-analog conversion module performs ADC conversion on the DC voltage signal and the DC current signal according to a fixed sampling frequency to obtain the DC voltage signal and the DC current signal in a digital quantity signal mode; The third digital-to-analog conversion module performs ADC conversion on the intermediate frequency voltage signal and the intermediate frequency current signal according to a fixed sampling frequency to obtain the intermediate frequency voltage signal and the intermediate frequency current signal in a digital quantity signal mode.

[0032] Step S2: The low-pass filter module performs a low-pass filter operation on the signal in the digital signal mode; Among them, the low-pass filtering operation method of the low-pass filtering module specifically includes: The first low-pass filtering module performs low-pass filtering on the power given signal in the digital signal mode obtained by the first digital-to-analog conversion module; The second low-pass filtering module performs low-pass filtering on the DC voltage signal and the DC current signal in the digital signal mode obtained by the second digital-to-analog conversion module; The third low-pass filtering module performs low-pass filtering on the intermediate frequency voltage signal and the intermediate frequency current signal in the digital signal mode obtained by the third digital-to-analog conversion module.

[0033] Step S3, the calculation module calculates the real-time power, PWM frequency and phase information of the electric furnace according to the digital signal filtered by the low-pass filter module; The calculation method of the calculation module specifically includes: The real-time power calculation module performs multiplication calculation on the DC voltage signal and the DC current signal filtered by the second low-pass filter module to obtain the real-time power of the electric furnace; The Fourier calculation module performs Fourier calculation on the intermediate frequency voltage signal and the intermediate frequency current signal after the third low-pass filtering process to obtain the PWM frequency and phase information of the electric furnace.

[0034] Step S4: The PWM frequency determination module judges and determines the PWM frequency of the control driving module according to the calculated real-time power, PWM frequency and phase information, and transmits the determined PWM frequency to the driving module.

[0035] The determination method of the PWM frequency determination module includes: The discrete PID calculation module performs discrete PID calculation actions according to the current communication or potentiometer given power value and the real-time power calculated by the calculation module; the calculation formula of the discrete PID calculation module is as follows: (1); in, is the output value, is the proportionality coefficient, is the deviation, is the integration coefficient, is the error integral, is the differential coefficient, is the set value, which is 1, 2, ..., , is the system sampling time; in, Proportional coefficient, setting hour, To set a constant value, when When , the proportional coefficient calculation formula is: (2); If you set and are less than or equal to 1, then the proportionality coefficient Less than or equal to 1, so that the heating temperature will not exceed the set temperature, which can effectively avoid the adverse effect of the heating temperature exceeding the set temperature on the heated object during the heating process; The integral coefficient is related to the heating target temperature. Different integral coefficient values ​​are set according to different target temperatures. The integral coefficient calculation formula is: (3); is the ambient temperature value, is a constant set according to the ambient temperature. The higher the ambient temperature, the smaller the value. is the difference between the furnace temperature and the ambient temperature. The higher the furnace temperature, the faster the heat dissipation. The larger the value, the higher the value. Different values ​​can be taken according to different target temperatures. During the temperature adjustment process, the deviation between the actual heating temperature and the target heating temperature is set as the target deviation value. When the actual temperature deviation value is greater than the target deviation value, the differential coefficient is 0 to improve the system response speed. When the actual temperature deviation value is less than the target deviation value, The differential coefficient formula is: (4) At this time, the differential coefficient is large, which improves the anti-interference performance of the system; The PWM frequency saturation judgment module compares the result calculated and output by the discrete PID calculation module with the PWM frequency and phase information calculated by the calculation module to determine whether the PWM frequency is saturated and limited. When the PWM frequency is determined to be in a saturated state, the PWM frequency calculated and output by the discrete PID calculation module is limited and transmitted to the drive module; when the PWM frequency is determined to be in an unsaturated state, the process ends.

[0036] Furthermore, the control method further includes: The power given signal, the DC voltage signal and the DC current signal, as well as the intermediate frequency voltage signal and the intermediate frequency current signal in the form of digital signal are stored in the corresponding memory array storage module.

[0037] The real-time power, PWM frequency and phase information obtained by the calculation module are displayed in the display module. The display module serves as an interactive interface between the user and the control system. It is used to display the operating status and parameter setting information of the control system, and obtain the user's operation instructions to exchange data with the digital signal processing unit through the communication protocol to realize human-computer interaction.

[0038] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are intended to be exemplary only, and the true scope of the present disclosure is indicated by the following claims.

Claims

1. An induction heating control system, characterized in that: The system comprises: A digital-to-analog conversion module, used for performing digital-to-analog conversion on the analog signal transmitted by the analog signal conditioning circuit to obtain a digital quantity signal, wherein the analog signal includes a power setting signal, a DC voltage signal, a DC current signal, an intermediate frequency voltage signal, and an intermediate frequency current signal; A low-pass filtering module, connected to the digital-to-analog conversion module, and configured to perform a low-pass filtering operation on a signal in a digital quantity signal mode; A calculation module, connected to the low-pass filter module, for calculating the real-time power, PWM frequency and phase information of the electric furnace according to the digital signal filtered by the low-pass filter module; The PWM frequency determination module is connected to the calculation module and is used to judge and determine the PWM frequency used to control the driving module according to the calculated real-time power, PWM frequency and phase information, and transmit the determined PWM frequency to the driving module.

2. The induction heating control system according to claim 1, characterized in that: The digital-to-analog conversion module comprises: The first digital-to-analog conversion module is used to perform ADC conversion on the power given signal according to a fixed sampling frequency to obtain the power given signal in a digital quantity signal mode; A second digital-to-analog conversion module is used to perform ADC conversion on the DC voltage signal and the DC current signal according to a fixed sampling frequency to obtain the DC voltage signal and the DC current signal in a digital quantity signal mode; The third digital-to-analog conversion module is used to perform ADC conversion on the intermediate frequency voltage signal and the intermediate frequency current signal according to a fixed sampling frequency to obtain the intermediate frequency voltage signal and the intermediate frequency current signal in a digital quantity signal mode.

3. The induction heating control system according to claim 2, characterized in that: The system further comprises: A storage module, connected to the first digital-to-analog conversion module, the second digital-to-analog conversion module and the third digital-to-analog conversion module, respectively, and used to store the power given signal, the DC voltage signal and the DC current signal, and the intermediate frequency voltage signal and the intermediate frequency current signal in the digital signal mode in the corresponding memory array; A display module is connected to the calculation module and is used to display the real-time power, PWM frequency and phase information obtained by the calculation module.

4. The induction heating control system according to claim 2, characterized in that: The low-pass filtering module specifically includes: A first low-pass filtering module is connected to the first digital-to-analog conversion module and is used to perform low-pass filtering on the power given signal in a digital signal mode obtained by the first digital-to-analog conversion module; A second low-pass filtering module is connected to the second digital-to-analog conversion module and is used to perform low-pass filtering on the DC voltage signal and the DC current signal in the digital signal mode obtained by the second digital-to-analog conversion module; The third low-pass filtering module is connected to the third digital-to-analog conversion module and is used to perform low-pass filtering on the intermediate frequency voltage signal and the intermediate frequency current signal in the digital signal mode obtained by the third digital-to-analog conversion module.

5. The induction heating control system according to claim 4, characterized in that: The calculation module comprises: A real-time power calculation module, connected to the second low-pass filtering module, and used to perform multiplication calculation on the DC voltage signal and the DC current signal filtered by the second low-pass filtering module to obtain the real-time power of the electric furnace; The Fourier calculation module is connected to the third low-pass filter module and is used to perform Fourier calculation on the intermediate frequency voltage signal and the intermediate frequency current signal after the third low-pass filter processing to obtain the PWM frequency and phase information of the electric furnace.

6. The induction heating control system according to claim 1, characterized in that: The PWM frequency determination module specifically includes: A discrete PID calculation module, used for executing discrete PID calculation actions according to the current communication or potentiometer given power value and the real-time power calculated by the calculation module; The PWM frequency saturation judgment module is connected to the calculation module, and is used to compare the result calculated and output by the discrete PID calculation module with the PWM frequency and phase information calculated by the calculation module to judge whether the PWM frequency is saturated and limited. When it is determined that the PWM frequency is in a saturated state, the PWM frequency calculated and output by the discrete PID calculation module is limited and transmitted to the driving module; when it is determined that the PWM frequency is in an unsaturated state, the process ends.

7. An induction heating control method, characterized in that: The method comprises: The digital-to-analog conversion module performs digital-to-analog conversion on the analog signal transmitted by the analog signal conditioning circuit to obtain a digital quantity signal, wherein the analog signal includes a power setting signal, a DC voltage signal, a DC current signal, an intermediate frequency voltage signal, and an intermediate frequency current signal; The low-pass filter module performs low-pass filtering operation on the signal in the digital signal mode; The calculation module calculates the real-time power, PWM frequency and phase information of the electric furnace according to the digital signal filtered by the low-pass filter module; The PWM frequency determination module judges and determines the PWM frequency of the control driving module according to the calculated real-time power, PWM frequency and phase information, and transmits the determined PWM frequency to the driving module.

8. The induction heating control method according to claim 1, characterized in that: The signal conversion method of the digital-to-analog conversion module specifically includes: The first digital-to-analog conversion module performs ADC conversion on the power given signal according to a fixed sampling frequency to obtain the power given signal in a digital quantity signal mode; The second digital-to-analog conversion module performs ADC conversion on the DC voltage signal and the DC current signal according to a fixed sampling frequency to obtain the DC voltage signal and the DC current signal in a digital quantity signal mode; The third digital-to-analog conversion module performs ADC conversion on the intermediate frequency voltage signal and the intermediate frequency current signal according to a fixed sampling frequency to obtain the intermediate frequency voltage signal and the intermediate frequency current signal in a digital quantity signal mode; The low-pass filtering operation method of the low-pass filtering module specifically includes: A first low-pass filtering module performs low-pass filtering on the power setting signal in a digital signal mode obtained by the first digital-to-analog conversion module; A second low-pass filtering module performs low-pass filtering on the DC voltage signal and the DC current signal in the digital signal mode obtained by the second digital-to-analog conversion module; A third low-pass filtering module performs low-pass filtering on the intermediate frequency voltage signal and the intermediate frequency current signal in the digital signal mode obtained by the third digital-to-analog conversion module; The calculation method of the calculation module specifically includes: The real-time power calculation module performs multiplication calculation on the DC voltage signal and the DC current signal filtered by the second low-pass filter module to obtain the real-time power of the electric furnace; The Fourier calculation module performs Fourier calculation on the intermediate frequency voltage signal and the intermediate frequency current signal after the third low-pass filtering process to obtain the PWM frequency and phase information of the electric furnace; The determination method of the PWM frequency determination module specifically includes: The discrete PID calculation module performs discrete PID calculation actions according to the current communication or potentiometer given power value and the real-time power calculated by the calculation module; the calculation formula of the discrete PID calculation module is as follows: （1）； in, is the output value, is the proportionality coefficient, is the deviation, is the integration coefficient, is the error integral, is the differential coefficient, is the set value, which is 1, 2, ..., , is the system sampling time; in, Proportional coefficient, setting hour, To set a constant value, when When , the proportional coefficient calculation formula is: （2）； The integral coefficient calculation formula is: (3); is the ambient temperature value, is a constant set according to the ambient temperature, is the difference between the furnace temperature and the ambient temperature; During the temperature adjustment process, the deviation between the actual heating temperature and the target heating temperature is set as the target deviation value. When the actual temperature deviation value is greater than the target deviation value, the differential coefficient is 0. When the actual temperature deviation value is less than the target deviation value, The differential coefficient formula is: (4); The PWM frequency saturation judgment module compares the result calculated and output by the discrete PID calculation module with the PWM frequency and phase information calculated by the calculation module to judge whether the PWM frequency is saturated and limited. When it is determined that the PWM frequency is in a saturated state, the PWM frequency calculated and output by the discrete PID calculation module is limited and transmitted to the driving module; when it is determined that the PWM frequency is in an unsaturated state, the process ends.

9. The induction heating control method according to claim 2, characterized in that: The control method further comprises: The power given signal, the DC voltage signal and the DC current signal, and the intermediate frequency voltage signal and the intermediate frequency current signal in the digital signal mode are stored in the corresponding memory array storage module; The real-time power, PWM frequency and phase information obtained by the calculation module are displayed in the display module.

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