Single-tube scheme line disc high-frequency current detection and control system and method

Abstract

This invention discloses a high-frequency current detection and control system and method based on a single-tube coil design. Two sets of qualified 200mm circumference flexible current probes (A and B) are used to test the IGBT current and coil current respectively. After connecting the BNC output interface to an oscilloscope, the flexible current probes greatly facilitate the selection of IGBTs and the design and quantitative evaluation of the coil cross-sectional area in single-tube induction cookers. This allows for isolated detection of high-frequency coil current in existing induction cookers, including single-burner and multi-burner models. A precise high-frequency current is generated through a sampling resistor and connected to the AD interface circuit of a DSP. Through the DSP's communication circuit, it can simultaneously communicate with the touch display panel of the existing induction cooker or a computer via an isolated serial port. The touch display panel then communicates with each induction cooker control board via an isolated serial port, achieving closed-loop control functions for cookware identification and cookware compatibility.

Description

Technical Field

[0001] This invention relates to the field of high-frequency current detection technology for induction cookers, specifically to a high-frequency current detection and control system and method based on a single-tube coil scheme. Background Technology

[0002] From a market perspective, induction cookers include single-burner and multi-burner models. Due to historical and cost reasons, the vast majority of them use a single-tube design. While this is adequate for heating standard pots, pots that are not heating properly may encounter unpredictable high-frequency currents, leading to the burnout of the IGBT and coil, resulting in a poor customer experience. As external market competition intensifies, the requirements for the cost-effectiveness and reliability of induction cookers are becoming increasingly stringent.

[0003] From a corporate perspective, the talent pool is largely familiar with 8-bit MCUs but lacks understanding of 32-bit DSPs. Induction cooker design remains in a rudimentary stage of low-frequency design and user function development, lacking IGBT and LC quantization design standards and cookware compatibility standards. Low-cost 8-bit MCUs often lack high-frequency current detection capabilities, leading to misjudgments in cookware identification and poor cookware compatibility design. Furthermore, some companies' induction cooker evaluations simply don't test the IGBT and coil high-frequency current. Others, while using expensive imported high-frequency current clamps, find their bulky size makes it impossible to directly test the IGBT current hidden under the various shapes of heat sinks on different induction cookers, forcing them to dig a large hole in the bottom shell of the induction cooker. A large notch of at least 3cm x 6cm is required. Then, use a sharp blade to cut the PCB between the IGBT and the collector (C) terminal on the main board. Next, find a copper wire about 5-7cm long and pass it through a current clamp to connect the collector (C) terminal of the IGBT. Since the single tube uses LC parallel resonance, it is very sensitive to the leakage inductance of the 5-7cm copper wire, which leads to a decrease in the stability of the single tube resonance. At the same time, the oscilloscope waveform has a certain degree of distortion. Therefore, it is impossible to confirm the authenticity of the high-frequency current of the induction cooker IGBT. It is also inconvenient to test the high-frequency current of various cookwares in multi-burner stoves for a long time. Therefore, it is impossible to select and quantitatively evaluate the IGBT. Even after the test is completed, the copper wire must be removed and the collector (C) terminal re-soldered, which may cause short circuits or poor soldering. The notch in the bottom shell affects the air duct and needs to be sealed with tape.

[0004] Therefore, there is a need to provide a high-frequency current detection and control system and method based on a single-tube coil to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a high-frequency current detection and control system and method based on a single-tube coil scheme, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] The invention relates to a single-tube scheme for detecting and controlling high-frequency current in a coil, comprising an open-loop detection system for IGBT and coil high-frequency current based on a single-tube scheme, and a closed-loop detection and control system for coil high-frequency current based on a single-tube scheme. The open-loop detection system includes two sets of flexible current probes, A and B. Flexible current probe A tests the IGBT current, and flexible current probe B tests the coil current. Both probes are connected to an oscilloscope via a BNC output interface. The closed-loop detection and control system includes the original induction cooker, a coil high-frequency current isolation detection circuit, and a DSP detection and control system.

[0008] Preferably, the original induction cooker is controlled by a touch screen via isolated serial communication A and isolated serial communication B, which control the two burners of phase A and phase B respectively.

[0009] Preferably, the high-frequency current isolation detection circuit of the coil includes 4 groups. The coil L1 under test in each group of the high-frequency current isolation detection circuit passes through the high-frequency current transformer CT1. The output of the high-frequency current transformer CT1 is connected to the bridge rectifier bridge, and the output current is converted into voltage through the precision sampling resistor R1. Voltage = R1 x (current under test / turns ratio). R2 and D5 pulled up to the DSP power supply voltage of 3.3V jointly provide overload current clamping protection.

[0010] Preferably, the DSP detection and control system includes a coil high-frequency current isolation detection circuit and an IC1 chip. The IC1 chip is a TMS320F28027 DSP signal processor. The output voltage INPUTA of the coil high-frequency current isolation detection circuit is connected to IC1-PIN8 (AD port) and PIN9- (comparator input port), respectively. The output voltage INPUTB of the coil high-frequency current isolation detection circuit is connected to IC1-PIN4 (AD port) and PIN5- (comparator input port), respectively. The output voltage INPUTC of the coil high-frequency current isolation detection circuit is connected to IC1-PIN13 (AD port) and PIN14- (comparator input port), respectively. The output voltage INPUTD of the coil high-frequency current isolation detection circuit is connected to IC1-PIN15 (AD port) and PIN16- (comparator input port), respectively.

[0011] Preferably, the DSP signal processor calculates the maximum and effective current of the coil at high speed through the input signal of the AD port, and converts the maximum and effective current of the IGBT according to the above formula of the IGBT based on the single-tube scheme and the open-loop detection system of the coil high-frequency current.

[0012] Preferably, the DSP signal processor can simultaneously communicate with the touch display panel of the original induction cooker or a computer via the DSP's isolated serial communication circuit, and the touch display panel can then communicate with each induction cooker control board via an isolated serial communication.

[0013] Preferably, the touch display screen is further extended with DSP isolated serial communication C and DSP remote shutdown dual relay interface.

[0014] Preferably, the IC used in the touch display screen is the BF7615AM28 model, which supports 3-channel serial communication.

[0015] A high-frequency current detection method for coils based on a single-tube scheme includes:

[0016] The method for detecting high-frequency current of IGBTs and coils based on a single-tube scheme includes the following steps:

[0017] S1. Select and test various cookware, establish a large database of cookware parameters, collect faulty cookware on the market that have exploded IGBTs and burned coils, test and record the IGBT current and coil current of standard cookware, honeycomb bottom and customized non-magnetic 304 cookware under embedded tooling when the standard coil spacing of the single tube scheme of the induction cooker is 10mm, when the LC is in parallel resonance.

[0018] S2. Test the standard pot. If the actual maximum current of the IGBT is found to exceed the ICpuls current allowed by the IGBT datasheet, it is necessary to increase L, adjust the plate spacing, or replace the IGBT while meeting the maximum power of the standard pot.

[0019] S3. Testing the honeycomb bottom and custom non-magnetic 304 cookware: In order to reduce the actual maximum current of the IGBT, the induction cooker needs to develop cookware recognition software first. If cookware recognition software cannot be developed, the IGBT reverse voltage protection setting value at 190 / 200 / 210 / 220VAC can be reduced to at least lower than the IGBT reverse voltage protection setting value at 230VAC. Finally, the IGBT temperature protection is relied upon. The effectiveness of the IGBT temperature protection depends on the selection and installation method of the IGBT temperature sensor.

[0020] S4. Use the combination keys on the touch screen to query the IGBT temperature. Based on the temperature difference between the thermocouple on the IGBT housing and the IGBT temperature, use the plus / minus keys to calibrate the IGBT temperature value, thereby ensuring the accuracy of the IGBT temperature.

[0021] A closed-loop detection and control method for high-frequency current in a coil based on a single-tube scheme includes the following steps:

[0022] S1. First, the induction cooker heats the standard pot to obtain the rated power. The DSP coil current is converted into IGBT current. The DSP transmits the data to the induction cooker. The induction cooker checks the IGBT current. If the IGBT current is not qualified, L is increased or the coil spacing is adjusted, and the cycle is repeated. If it is ineffective, the IGBT specification is changed and the cycle is repeated until the maximum value current of the IGBT is qualified.

[0023] S2. Check if the current density of the coil is qualified. If it is not qualified, adjust the coil structure and cross-sectional area, and then cycle. If the current density of the coil is qualified, replace it with another pot.

[0024] S3. Check if the IGBT current of the induction cooker exceeds the standard IGBT current of the standard pot. If it does, reduce the maximum power of other pots and lower the 190 / 200 / 210 / 220VAC IGBT reverse voltage protection setting. If it does not exceed the standard, proceed with the IGBT case temperature calibration process: upload the induction cooker IGBT case temperature data to the computer, upload the IGBT case temperature thermocouple data to the computer, perform difference analysis when the fan is running and when it is stopped, and modify the induction cooker software to calibrate the IGBT case temperature.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. Using two sets of qualified 200mm circumference flexible current probes (A and B), the IGBT current and coil current were tested respectively. After connecting the BNC output interface to an oscilloscope, the relationship between the maximum and effective values ​​of the IGBT and coil current in a large number of single-tube induction cookers was calculated and analyzed after setting the phase, range, and units. The conversion formula between the two was summarized. The flexible current probe greatly facilitates the selection of IGBTs and the design and quantitative evaluation of the coil cross-sectional area in single-tube induction cooker solutions.

[0027] 2. For existing induction cookers, including single-burner or multi-burner models, isolate and detect the high-frequency current of the coil. Optimize low-cost passive high-frequency current transformers, passing them through the induction cooker coil. The output current passes through a optimized low-cost bridge rectifier, and through a sampling resistor, generates a precise high-frequency current. This current is connected to the AD interface circuit of the DSP. The DSP has 32-bit high-speed real-time calculation capabilities, automatically calculating the maximum and effective current of the induction cooker coil and converting them to the maximum and effective current of the IGBT. Through the DSP's communication circuit, it can simultaneously communicate with the original induction cooker's touch display panel or a computer via an isolated serial port. The touch display panel then communicates with each induction cooker control board via an isolated serial port, achieving cookware identification and cookware compatibility closed-loop control functions.

[0028] Meanwhile, the DSP can remotely shut down the relays controlling the A and B phase power lines of the original induction cooker via optical coupling, preventing further damage to the power line fuses, relay contacts, and coils during induction cooker malfunctions.

[0029] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0030] Figure 1 This is a diagram of the open-loop detection system for high-frequency current of IGBT and coil based on a single-tube scheme according to the present invention.

[0031] Figure 2 The waveforms of the oscilloscope for the 304-240mm stainless steel pot, 220VAC, 2.2KW, IGBT current, and coil current with a time base of 2ms are shown in the figure.

[0032] Figure 3 The oscilloscope waveform diagram after expanding the 2ms time base of IGBT current and coil current to 10us in this invention;

[0033] Figure 4 This is a flowchart of the high-frequency current detection method for IGBTs and coils based on a single-tube scheme according to the present invention.

[0034] Figure 5 The system block diagram for this invention, which requires parallel IGBTs with a power output of 3-3.5KW;

[0035] Figure 6 This is a diagram of the closed-loop detection and control system for high-frequency current of a coil based on a single-tube scheme according to the present invention.

[0036] Figure 7 This is a circuit diagram of the high-frequency current isolation detection circuit of the coil of the present invention;

[0037] Figure 8 This is a diagram of the DSP detection and control system of the present invention;

[0038] Figure 9 This is a flowchart illustrating the cookware compatibility design of the closed-loop detection and control system for high-frequency current of a coil based on a single-tube scheme according to the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Please see Figures 1-9 The embodiments provided by the present invention are as follows:

[0041] Example 1

[0042] like Figures 1-3 As shown, a high-frequency current detection and control system and method based on a single-tube coil scheme is presented. This includes an open-loop detection system for the high-frequency current of the IGBT and coil based on a single-tube scheme. The open-loop detection system comprises two sets of flexible current probes, A and B, both with a circumference of 200mm. Flexible current probe A measures the IGBT current, while flexible current probe B measures the coil current. Both probes are connected to an oscilloscope via a BNC output interface. After setting the phase, range, and units, the relationship between the maximum and effective current values ​​of the IGBT and coil induction cooker for a large number of single-tube induction cookers was calculated and analyzed. The conversion formulas are summarized as follows: IGBT maximum current = 1.03~1.08 x coil maximum current; IGBT effective current = 0.6~0.7 x coil effective current.

[0043] For a 3-3.5KW single-tube solution, parallel IGBTs are required. Two sets of qualified 200mm perimeter flexible current probes (A and B) are used to test the IGBTA and IGBTB currents respectively. After connecting the BNC output interface to an oscilloscope, and adjusting the phase, range, and units, the consistency of the IGBTA and IGBTB currents can be compared. The flexible current probes greatly facilitate the selection of IGBTs and the design and quantitative evaluation of the coil cross-sectional area for single-tube induction cooker solutions.

[0044] Specifically, such as Figure 1 As shown, two sets of qualified 200mm circumference flexible current probes (A and B) were used to test the IGBT current and coil current respectively. After connecting the BNC output interface to an oscilloscope, the relationship between the maximum and effective values ​​of the IGBT and coil current in a large number of single-tube induction cookers was calculated and analyzed after setting the phase, range, and units. The conversion formula between the two was summarized as follows: maximum IGBT current = 1.03~1.08 x maximum coil current, effective IGBT current = 0.6~0.7 x effective coil current.

[0045] like Figure 2 As shown, a 304-240mm stainless steel pot with 220VAC and 2.2KW power supply was used for testing. The IGBT current and coil current waveforms were obtained from an oscilloscope with a time base of 2ms. The RMS of the IGBT in CH1 was 20.24A, and the RMS of the coil in CH4 was 31.99A. The effective current of the IGBT / the effective current of the coil = 20.24 / 31.99 = 0.63, which conforms to the above formula.

[0046] like Figure 3 As shown, a 220VAC 2.2KW 304-240mm stainless steel was used for testing. The IGBT current and coil current were expanded to 10us oscilloscope waveforms with a time base of 2ms. The IGBT Max of CH1 was 64A, the baseline was -8A, and the actual maximum value of the IGBT was Max - baseline = 64 - (-8) = 72A. The coil Max of CH4 was 68A. The actual maximum value current of the IGBT / the maximum value current of the coil was 72 / 68 = 1.06, which conforms to the above formula.

[0047] It is worth noting that, for example Figure 5 As shown, for 3-3.5KW, parallel IGBTs are required. Two sets of qualified 200mm circumference flexible current probes (A and B) are used to test the IGBT A current and IGBT B current respectively. After connecting the BNC output interface to an oscilloscope, and adjusting the phase, range, and units, the consistency of the IGBT A current and IGBT B current can be compared.

[0048] like Figure 4 As shown, the method for detecting high-frequency current of IGBTs and coils based on a single-tube scheme includes the following steps:

[0049] S1. Select and test various cookware, establish a large database of cookware parameters, especially collect faulty cookware on the market that have exploded IGBTs and burned coils, test and record the IGBT current and coil current of standard cookware, honeycomb bottom and customized non-magnetic 304 cookware under embedded tooling when the standard coil spacing of the single tube scheme of the induction cooker is about 10mm, when the LC is in parallel resonance.

[0050] S2. Test the standard pot. If the actual maximum current of the IGBT is found to exceed the ICpuls current allowed by the IGBT datasheet, it is necessary to increase L, adjust the plate spacing, or replace the IGBT while meeting the maximum power of the standard pot.

[0051] S3. Testing the honeycomb bottom and custom non-magnetic 304 cookware: In order to reduce the actual maximum current of the IGBT, the induction cooker needs to develop cookware recognition software first. If cookware recognition software cannot be developed, the IGBT reverse voltage protection setting value at 190 / 200 / 210 / 220VAC can be reduced to at least lower than the IGBT reverse voltage protection setting value at 230VAC. Finally, the IGBT temperature protection is relied upon. The effectiveness of the IGBT temperature protection depends on the selection and installation method of the IGBT temperature sensor.

[0052] S4. Use the combination keys on the touch screen to query the IGBT temperature. Based on the temperature difference between the thermocouple on the IGBT housing and the IGBT temperature, use the plus / minus keys to calibrate the IGBT temperature value, thereby ensuring the accuracy of the IGBT temperature.

[0053] Example 2

[0054] like Figure 6 As shown, a high-frequency current detection and control system and method for coils based on a single-tube scheme are disclosed. The system includes a closed-loop detection and control system for high-frequency current of the coil based on a single-tube scheme. The closed-loop detection and control system for high-frequency current of the coil based on a single-tube scheme includes the original induction cooker, a high-frequency current isolation detection circuit for the coil, and a DSP detection and control system.

[0055] The original induction cooker was controlled by a touch screen via isolated serial communication A and isolated serial communication B to control the two burners of phase A and phase B respectively. The touch screen has also been expanded to include DSP isolated serial communication C and DSP remote shutdown dual relay interface.

[0056] like Figure 7 As shown, the high-frequency current isolation detection circuit for the coil includes four groups. The coil L1 under test in each group of the high-frequency current isolation detection circuit passes through the high-frequency current transformer CT1. The output of the high-frequency current transformer CT1 is connected to the bridge rectifier bridge, and the output current is converted into voltage through the precision sampling resistor R1. Voltage = R1 x (current under test / turns ratio). R2 and D5, which is pulled up to the DSP power supply voltage of 3.3V, work together to clamp and protect against overload current.

[0057] like Figure 8 As shown, the DSP detection and control system includes a coil high-frequency current isolation detection circuit and an IC1 chip. The output voltage INPUTA of the coil high-frequency current isolation detection circuit is connected to IC1-PIN8 (AD port) and PIN9- (comparator input port), respectively. The output voltage INPUTB of the coil high-frequency current isolation detection circuit is connected to IC1-PIN4 (AD port) and PIN5- (comparator input port), respectively. The output voltage INPUTC of the coil high-frequency current isolation detection circuit is connected to IC1-PIN13 (AD port) and PIN14- (comparator input port), respectively. The output voltage INPUTD of the coil high-frequency current isolation detection circuit is connected to IC1-PIN15 (AD port) and PIN16- (comparator input port), respectively.

[0058] The IC1 chip is a DSP signal processor with 32-bit high-speed real-time calculation capabilities. The DSP signal processor calculates the maximum and effective current of the coil at high speed through the input signal of the AD port, and converts the maximum and effective current of the IGBT according to the above formulas of the IGBT based on the single-tube scheme and the open-loop detection system of the coil high-frequency current.

[0059] The DSP signal processor can communicate with the original induction cooker's touch display panel or computer via the DSP's isolated serial communication circuit. The touch display panel then communicates with each induction cooker control board via isolated serial communication, thus realizing the closed-loop control function of cookware identification and cookware compatibility.

[0060] In addition, if the induction cooker experiences a coil fault current greater than the maximum value current, it can be quickly detected through the comparator input port mentioned above, and a high level will be output through IC1-PIN28 (comparator output port) to turn on the optocoupler IC2. The output of IC2 can remotely shut off the relays of the original induction cooker control A-phase and B-phase power lines, preventing further burnout of the power line fuses, relay contacts and coils in the induction cooker fault mode.

[0061] IC1-CN1 is the JTAG debugging and program download port, and DSP-CN2 is the UART port. The UART can be connected to the original induction cooker touch screen through the isolated serial communication port C, and then connected to the computer through the isolated USB-TTL converter.

[0062] Other peripheral circuits of the DSP include a 3.3V power supply circuit, filtering and decoupling circuits, and a crystal oscillator circuit.

[0063] The preferred DSP-IC is the TMS320F28027, with an XTAL-10MHz crystal oscillator and a 6x phase-locked loop (PLL) setting.

[0064] The preferred touch display IC is the BF7615AM28, which supports 3-channel serial communication.

[0065] The preferred switching power supply for the relays controlling the A-phase and B-phase power lines of the original induction cooker is PH8147H.

[0066] like Figure 9 As shown, the closed-loop detection and control method for high-frequency current of a coil based on a single-tube scheme includes the following steps:

[0067] S1. First, the induction cooker heats the standard pot to obtain the rated power. The DSP coil current is converted into IGBT current. The DSP transmits the data to the induction cooker. The induction cooker checks the IGBT current. If the IGBT current is not qualified, L is increased or the coil spacing is adjusted, and the cycle is repeated. If it is ineffective, the IGBT specification is changed and the cycle is repeated until the maximum value current of the IGBT is qualified.

[0068] S2. Check if the current density of the coil is qualified. If it is not qualified, adjust the coil structure and cross-sectional area, and then circulate. If the current density of the coil is qualified, replace it with other pots, preferably honeycomb bottom or custom non-magnetic 304 pots.

[0069] S3. Check if the IGBT current of the induction cooker exceeds the standard IGBT current of the standard pot. If it does, reduce the maximum power of other pots and lower the 190 / 200 / 210 / 220VAC IGBT reverse voltage protection setting. If it does not exceed the standard, proceed with the IGBT case temperature calibration process: upload the induction cooker IGBT case temperature data to the computer, upload the IGBT case temperature thermocouple data to the computer, perform difference analysis when the fan is running and when it is stopped, and modify the induction cooker software to calibrate the IGBT case temperature.

[0070] Furthermore, the most challenging aspect of the single-tube induction cooker solution is that, due to cost constraints, the induction cooker does not include a coil temperature sensor. Although the IGBT current of other pots, preferably with honeycomb bottoms or custom-made non-magnetic 304 stainless steel, can be controlled to be no higher than that of standard pots, the coil current frequency of these pots is higher than that of standard pots. Due to the significant high-frequency current attraction effect of the coil, the coil temperature of these pots is higher than that of standard pots. To address this, this invention uses a flexible probe to test the effective value and cross-sectional area of ​​the coil, calculates the coil current density, and determines the conversion formula between the coil current density recorded by the computer and the temperature of the temporary thermocouple installed on the coil under given installation and heat dissipation conditions. This allows the induction cooker to directly display the converted coil temperature without installing a coil temperature sensor, and to control the power of the honeycomb bottom or custom-made non-magnetic 304 stainless steel pot through a closed-loop control based on the coil current density or the converted coil temperature. For aluminum coils with a temperature range of 180~220 degrees Celsius, the preferred coil current density is below 5A / mm², and should not exceed 7A / mm².

[0071] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-frequency current detection and control system based on a single-tube coil, characterized in that, The system includes an open-loop detection system for IGBT and coil high-frequency current based on a single-tube scheme, and a closed-loop detection and control system for coil high-frequency current based on a single-tube scheme. The open-loop detection system for IGBT and coil high-frequency current based on a single-tube scheme includes two sets of flexible current probes A and B. Flexible current probe A tests the IGBT current, and flexible current probe B tests the coil current. Flexible current probes A and B are then connected to an oscilloscope via a BNC output interface. The closed-loop detection and control system for coil high-frequency current based on a single-tube scheme includes the original induction cooker, a coil high-frequency current isolation detection circuit, and a DSP detection and control system.

2. The high-frequency current detection and control system based on a single-tube coil according to claim 1, characterized in that: The original induction cooker was controlled by a touch screen via isolated serial communication A and isolated serial communication B, which controlled the two burner heads of phase A and phase B respectively.

3. The high-frequency current detection and control system based on a single-tube scheme for coils according to claim 2, characterized in that: The high-frequency current isolation detection circuit for the coil includes four groups. In each group, the coil L1 under test passes through a high-frequency current transformer CT1. The output of the high-frequency current transformer CT1 is connected to a bridge rectifier bridge, and the output current is converted into voltage through a precision sampling resistor R1. The voltage = R1 x (current under test / turns ratio). R2 and D5, which is pulled up to the DSP power supply voltage of 3.3V, work together to clamp and protect against overload current.

4. The high-frequency current detection and control system based on a single-tube scheme for coils according to claim 3, characterized in that: The DSP detection and control system includes a coil high-frequency current isolation detection circuit and an IC1 chip. The IC1 chip is a TMS320F28027 DSP signal processor. The output voltage INPUTA of the coil high-frequency current isolation detection circuit is connected to IC1-PIN8 (AD port) and PIN9- (comparator input port). The output voltage INPUTB of the coil high-frequency current isolation detection circuit is connected to IC1-PIN4 (AD port) and PIN5- (comparator input port). The output voltage INPUTC of the coil high-frequency current isolation detection circuit is connected to IC1-PIN13 (AD port) and PIN14- (comparator input port). The output voltage INPUTD of the coil high-frequency current isolation detection circuit is connected to IC1-PIN15 (AD port) and PIN16- (comparator input port).

5. The high-frequency current detection and control system based on a single-tube scheme for coils according to claim 4, characterized in that: The DSP signal processor calculates the maximum and effective current of the coil at high speed using the input signal, and converts the maximum and effective current of the IGBT according to the formula of the IGBT based on the single-tube scheme and the open-loop detection system of the coil high-frequency current.

6. The high-frequency current detection and control system based on a single-tube scheme for coils according to claim 5, characterized in that: The DSP signal processor can simultaneously communicate with the touch display panel of the original induction cooker or a computer via the DSP's isolated serial communication circuit. The touch display panel then communicates with each induction cooker control board via an isolated serial communication.

7. The high-frequency current detection and control system based on a single-tube scheme for coils according to claim 2, characterized in that: The touch display screen is also expanded to include a DSP isolated serial communication C and a DSP remote shutdown dual relay interface.

8. The high-frequency current detection and control system based on a single-tube scheme for coils according to claim 7, characterized in that: The touch display screen uses the BF7615AM28 IC, which supports 3-channel serial communication.

9. A method for high-frequency current detection of a coil based on a single-tube scheme, comprising the high-frequency current detection and control system for a coil based on a single-tube scheme as described in any one of claims 1-7, further comprising: The method for detecting high-frequency current of IGBTs and coils based on a single-tube scheme includes the following steps: S1. Select and test various cookware, establish a large database of cookware parameters, collect faulty cookware on the market that have exploded IGBTs and burned coils, test and record the IGBT current and coil current of standard cookware, honeycomb bottom and customized non-magnetic 304 cookware under embedded tooling when the standard coil spacing of the single tube scheme of the induction cooker is 10mm, when the LC is in parallel resonance. S2. Test the standard pot. If the actual maximum current of the IGBT is found to exceed the ICpuls current allowed by the IGBT datasheet, it is necessary to increase L, adjust the plate spacing, or replace the IGBT while meeting the maximum power of the standard pot. S3. Testing the honeycomb bottom and custom non-magnetic 304 cookware: In order to reduce the actual maximum current of the IGBT, the induction cooker needs to develop cookware recognition software first. If cookware recognition software cannot be developed, the IGBT reverse voltage protection setting value at 190 / 200 / 210 / 220VAC can be reduced to at least lower than the IGBT reverse voltage protection setting value at 230VAC. Finally, the IGBT temperature protection is relied upon. The effectiveness of the IGBT temperature protection depends on the selection and installation method of the IGBT temperature sensor. S4. Use the combination keys on the touch screen to query the IGBT temperature. Based on the temperature difference between the thermocouple on the IGBT housing and the IGBT temperature, use the plus / minus keys to calibrate the IGBT temperature value, thereby ensuring the accuracy of the IGBT temperature. A closed-loop detection and control method for high-frequency current in a coil based on a single-tube scheme includes the following steps: S1. First, the induction cooker heats the standard pot to obtain the rated power. The DSP coil current is converted into IGBT current. The DSP transmits the data to the induction cooker. The induction cooker checks the IGBT current. If the IGBT current is not qualified, L is increased or the coil spacing is adjusted, and the cycle is repeated. If it is ineffective, the IGBT specification is changed and the cycle is repeated until the maximum value current of the IGBT is qualified. S2. Check if the current density of the coil is qualified. If it is not qualified, adjust the coil structure and cross-sectional area, and then cycle. If the current density of the coil is qualified, replace it with another pot. S3. Check if the IGBT current of the induction cooker exceeds the standard IGBT current of the standard pot. If it does, reduce the maximum power of other pots and lower the 190 / 200 / 210 / 220VAC IGBT reverse voltage protection setting. If it does not exceed the standard, proceed with the IGBT case temperature calibration process: upload the induction cooker IGBT case temperature data to the computer, upload the IGBT case temperature thermocouple data to the computer, perform difference analysis when the fan is running and when it is stopped, and modify the induction cooker software to calibrate the IGBT case temperature.

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