A fully digital welding power supply current type control method and circuit

Abstract

The invention discloses a fully digital welding power supply current type control method and circuit, and relates to the field of welding power supply control technology. The control method includes setting a timer, setting a PWM signal at the beginning of the timing, resetting the PWM signal after the timing reaches a first set value, and outputting PWM1 and PWM2 signals in a push-pull manner respectively, which are used to control the inverter output; collecting the welding power supply output signal, and converting it into a digital signal, and then converting it into a ramp analog signal after a PID algorithm and slope compensation. In one cycle, when the decreasing ramp analog quantity is equal to the increasing primary current quantity, a reset pulse signal is output, and the pulse width of PWM1 and PWM2 signals is adjusted to realize the control of the welding power supply output. The control circuit includes a welding power supply circuit, a feedback signal processing circuit, a controller circuit, a primary current signal processing circuit, and a drive circuit, and the controller circuit includes an STM32G4 series chip. The present application realizes fully digital current type control of the welding power supply, and the circuit is simple and cost-effective.

Description

Technical Field

[0001] The invention relates to the technical field of welding power supply control, and in particular to a full digital welding power supply current type control method and circuit. Background Art

[0002] At present, with the development of welding power supply and semiconductor technology, digital control of welding power supply is becoming more and more popular. However, the degree of digitization varies. For example, only the digitization of welding power supply timing control or the digitization of PID adjustment is realized; for example, the solution of DSP plus CPLD (FPGA), the DSP implements the PID digital algorithm and then the CPLD implements PWM control. The common types of welding power supply control are: voltage control and current control. Voltage control is mainly used for half-bridge inverter and full-bridge inverter circuit with anti-bias magnetic circuit, while current control is mostly used for full-bridge inverter, which can effectively suppress the bias magnetic problem of transformer and also has the function of input voltage feedforward, so it is also widely used. However, to realize the current digital control of power supply, it is necessary to control the primary current, and in most cases, slope compensation control is also required. There are many options for implementing current-mode control using analog integrated circuits, such as UCC3846, but there are not many chips that can implement current-mode control digitally. The most common ones are TI's TMS320 series and MICROCHIP's dsPIC series. However, they are somewhat complicated to use in practice and are relatively expensive, with a low cost-performance ratio, and cannot be used on cost-sensitive products.

[0003] Therefore, designing a fully digital current-controlled welding power supply is an urgent problem to be solved. Summary of the invention

[0004] The purpose of the present invention is to provide a fully digital welding power supply current type control method and circuit, which generates push-pull control signals PWM1 and PWM2 in a timer manner for full-bridge control of an inverter circuit, samples the welding power supply output current, and converts it into a digital signal. After PID calculation and slope compensation, it is converted into an analog quantity to obtain a ramp analog signal, compares the ramp analog quantity with the primary current analog quantity, outputs a reset signal, and adjusts the pulse width of PWM1 and PWM2, thereby realizing control of the welding power supply output. The circuit of the present application is simple and cost-effective.

[0005] In the first aspect, the above-mentioned invention object of the present invention is achieved through the following technical solutions:

[0006] A fully digital welding power supply current type control method is provided. A timer is set. When the timing starts, a PWM signal is set. After the timing reaches a first set value, the PWM signal is reset. PWM1 and PWM2 signals are output in a push-pull manner respectively to control the inverter output. The welding power supply output signal is collected and converted into a digital signal. After a PID algorithm and slope compensation, it is converted into a slope analog signal. In one cycle, when the decreasing slope analog quantity is equal to the increasing primary current, a reset pulse signal is output to adjust the pulse width of PWM1 and PWM2 signals to realize the output control of the welding power supply.

[0007] The present invention is further configured to: continue timing after the timing reaches a first set value, and reset the timer after reaching a second set value; and turn off the PWM2 or PWM1 signal before the PWM1 or PWM2 signal starts.

[0008] The present invention is further configured such that the slope of the ramp analog signal can be optimized and adjusted according to parameters, and when the output current increases, the ramp analog signal moves up, and when the output current decreases, the ramp analog signal moves down.

[0009] In a second aspect, the above-mentioned object of the present invention is achieved through the following technical solutions:

[0010] A fully digital welding power supply current type control circuit comprises a welding power supply circuit, a feedback signal processing circuit, a controller circuit, a primary current signal processing circuit and a drive circuit. One end of the feedback signal processing circuit, one end of the primary current signal processing circuit and one end of the drive circuit are respectively connected to the welding power supply circuit. Meanwhile, the other end of the feedback signal processing circuit, the other end of the primary current signal processing circuit and the other end of the drive circuit are respectively connected to the controller circuit. The feedback signal processing circuit is used to collect the output size of the welding power supply. The primary current signal processing circuit is used to collect the size of the primary current. The controller circuit is used to generate push-pull PWM1 and PWM2 signals in a timing manner, convert the output analog quantity of the welding power supply into a digital signal, and then convert it into a ramp analog signal after PID algorithm processing and slope compensation. In the same cycle, the decreasing ramp analog quantity is compared with the increasing primary current quantity, and a reset pulse signal is output according to the comparison result to control the pulse width of the PWM1 and PWM2 signals, thereby controlling the output of the welding power supply.

[0011] The present invention is further configured as follows: the welding power supply circuit includes a primary rectifier filter circuit, an inverter circuit, a high-frequency transformer circuit, and a secondary rectifier filter circuit connected in sequence; the feedback signal processing circuit is connected to the output of the secondary rectifier filter circuit and is used to collect the output size of the welding power supply; one end of the primary current signal processing circuit is connected to the output end of the inverter circuit and is used to collect the primary current; the drive circuit is connected to the inverter circuit and is used to control the output of the inverter circuit.

[0012] The present invention is further configured as follows: the controller circuit includes an analog-to-digital conversion circuit, an operation center circuit, a digital-to-analog conversion circuit, a comparator circuit, and a high-precision timer circuit connected in sequence; the operation center circuit is used to perform PID operation on the digital signal of the analog-to-digital conversion circuit; the digital-to-analog conversion circuit converts the operation result into an analog signal; the comparator circuit is used to compare the analog signal with the primary current sampling signal; and the high-precision timer circuit controls the PWM signal according to the output of the comparator circuit.

[0013] The present invention is further configured as follows: the high-precision timer circuit includes a timer unit and three comparison units, the first comparison unit is connected to the timer unit, and is used to compare the output of the timer unit with a set value; the second comparison unit is connected to the first comparison unit and the comparator circuit, and is used to output a PWM1 signal; the third comparison unit is connected to the first comparison unit and the comparator circuit, and is used to output a PWM2 signal, and the PWM1 signal and the PWM2 signal are push-pull mode signals.

[0014] The present invention is further configured to include: a setting circuit connected to the analog-to-digital conversion circuit and the operation center circuit, which is used to perform summation or difference calculation between the analog-to-digital conversion circuit and the set value and output it to the operation center.

[0015] The present invention is further configured as follows: the controller circuit adopts an STM32G4 series chip, and adopts a high-precision timer circuit in the chip. At the beginning of the timing, the PWM signal is set and the ADC sampling is triggered. After the timing reaches a first set value, the PWM signal is reset, and PWM1 and PWM2 signals are output in a push-pull manner respectively, so as to control the inverter output; the ADC circuit in the chip is adopted to convert the analog signal output by the welding power supply into a digital signal, and after summing with the constant output set value, the digital signal is converted into a ramp analog signal by the DAC circuit in the chip after the PID algorithm and slope compensation; the comparator in the chip compares the decreasing ramp analog quantity with the increasing primary current, and outputs the comparison result to the high-precision timer circuit in the chip. When the ramp analog quantity is equal to the primary current, a reset pulse signal is output, the pulse width of the PWM1 and PWM2 signals is adjusted, and the output control of the welding power supply is realized through the driving circuit.

[0016] The present invention is further configured as follows: the control of the STM32G4 series chip comprises the following steps:

[0017] S1, precision timer circuit generates PWM1, PWM2 signals, and triggers ADC sampling when PWM1 or PWM2 signal is set;

[0018] S2, after ADC sampling is completed, DMA transmission is triggered, and the current analog signal is converted into a current digital signal and then transmitted to the computing center;

[0019] S3, trigger DMA interrupt after DMA transfer is completed;

[0020] S4, perform power timing control, PID calculation, and update DAC output;

[0021] S5, the updated DAC output is subjected to slope compensation to obtain a decreasing slope analog signal, which is compared with the increasing primary current signal, and a reset pulse signal is output to adjust the pulse width of PWM1 and PWM2 signals;

[0022] S6, go to S1.

[0023] Compared with the prior art, the beneficial technical effects of this application are:

[0024] 1. This application generates a push-pull inverter full-bridge control signal through a high-precision timer circuit, and controls the pulse width of the inverter full-bridge control signal according to the power supply output current and the primary current, thereby realizing full digital control of the current type;

[0025] 2. Furthermore, the present application realizes the wave-by-wave limitation of the primary current through PID calculation and slope compensation, plays a role in suppressing the magnetic bias of the high-frequency transformer, and limits the peak current of the full-bridge power tube in real time;

[0026] 3. Furthermore, the present application controls the pulse duty cycle of the inverter full bridge by comparing the welding power supply output current with the primary current, thereby achieving welding power supply output control and characteristic control. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of a timing structure of a specific embodiment of the present application;

[0028] Figure 2 is a circuit structure diagram of a specific embodiment of the present application;

[0029] Figure 3 It is a schematic diagram of the timing structure of the STM32G4 series chip of a specific embodiment of the present application. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with the accompanying drawings. Specific embodiment 1

[0032] A fully digital welding power supply current type control method of the present application, such as Figure 1As shown, it includes setting a timer. When the timing starts, a cycle is started, and the PWM1 signal is set. After the timing reaches a first set value, the PMW1 signal is reset. After the PMW1 signal is reset, the timer continues to time to ensure that the PWM2 signal is turned off before PWM1 starts. After the timing reaches a second set value, this cycle ends, the timer returns to zero, and the PWM2 signal is set. After the timing reaches the first set value, the PMW2 signal is reset. After the PMW2 signal is reset, the timer continues to time to ensure that the PWM1 signal is turned off before PWM2 starts. After the timing reaches the second set value, this cycle ends, the timer returns to zero, and the PWM1 signal is set.

[0033] Similarly, PWM1 and PWM2 signals are output in a push-pull manner to control the conduction time of the inverter full-bridge power tube, such as the conduction time of IGBT or MOSFET, so as to control the inverter output. Before PWM1 is started, the PWM2 signal is turned off, and before PWM2 is started, the PWM1 signal is turned off to avoid safety hazards caused by the simultaneous conduction of the inverter full bridge.

[0034] The welding power supply output signal is collected and converted into a digital signal. After the PID algorithm and slope compensation, it is converted into a slope analog signal, that is, a DAC output signal. In one cycle, this signal is a decreasing slope signal. At the same time, the magnitude of the primary current is detected. In one cycle, the primary current is increasing. When the decreasing slope analog quantity is equal to the increasing primary current, a reset pulse signal is output. When the reset pulse appears, the PWM1 or PWM2 signal is turned off. When there is feedback, the drive PWM1 and drive PWM2 signals are output, realizing the pulse width adjustment of PWM1 and PWM2, and then realizing the output control of the welding power supply.

[0035] When the welding power output increases, the DAC output signal moves up as a whole. Conversely, when the welding power output decreases, the DAC output signal moves down as a whole. At this time, the position where the DAC output is equal to the primary current changes, thereby changing the reset pulse signal position and the pulse width of the PWM1 and PWM2 signals.

[0036] Adjust the parameters to adjust the slope of the ramp signal and optimize the welding power output. Specific embodiment 2

[0038] A fully digital welding power supply current type control circuit of the present application, such as Figure 2As shown, it includes a welding power supply circuit, a feedback signal processing circuit, a controller circuit, a primary current signal processing circuit, and a drive circuit. One end of the feedback signal processing circuit, one end of the primary current signal processing circuit, and one end of the drive circuit are respectively connected to the welding power supply circuit. At the same time, the other end of the feedback signal processing circuit, the other end of the primary current signal processing circuit, and the other end of the drive circuit are respectively connected to the controller circuit.

[0039] The feedback signal processing circuit is used to collect the output size of the welding power supply; the primary current signal processing circuit is used to collect the size of the primary current; the controller circuit is used to generate push-pull PWM1 and PWM2 signals in a timing manner, and convert the analog quantity of the welding power supply output into a digital signal, which is then converted into a ramp analog signal after PID algorithm processing and slope compensation. In one cycle, the ramp analog signal is decreasing and the primary current signal is increasing. The ramp analog quantity is compared with the primary current, and a reset pulse signal is output according to the comparison result to control the pulse width of the PWM1 and PWM2 signals, thereby controlling the output of the welding power supply.

[0040] The welding power supply circuit includes a primary rectifier and filter circuit, an inverter circuit, a high-frequency transformer circuit, and a secondary rectifier and filter circuit which are connected in sequence. The primary rectifier and filter circuit is used to rectify and filter the input current to convert it into a first direct current. The inverter circuit is used to convert the first direct current into primary high-frequency electricity through an inverter full-bridge circuit. The high-frequency transformer circuit is used to transfer the primary high-frequency electricity to the secondary high-frequency electricity. The secondary rectifier and filter circuit is used to rectify and filter the secondary high-frequency electricity and then output it as a second direct current.

[0041] The feedback signal processing circuit is connected to the output of the secondary rectifier filter circuit to collect the output size of the second direct current of the welding power supply. One end of the primary current signal processing circuit is connected to the output end of the inverter circuit and the input end of the high-frequency transformer circuit to collect the primary current. The drive circuit is connected to the inverter circuit to control the conduction time of the inverter full-bridge power tube, thereby controlling the output of the inverter circuit.

[0042] The driving circuit is used to drive the power tube of the inverter full bridge to turn on or off according to the push-pull PWM1 and PWM2 signals.

[0043] The primary current sampling signal processing circuit is used to sample and process the primary current to obtain a primary current sampling signal that increases in a cycle.

[0044] The controller circuit includes an analog-to-digital conversion circuit ADC, a setting circuit, an operation center circuit, a digital-to-analog conversion circuit DAC, a comparator circuit COMP, and a high-precision timer circuit HRTIM which are connected in sequence.

[0045] The analog-to-digital conversion circuit ADC is used to convert the collected analog signal output by the welding power supply into an output digital signal.

[0046] The setting circuit is used to perform a summation or difference operation on the analog-to-digital conversion circuit and a third setting value, and output the operation result to the operation center. The third setting value is used to set a constant current or constant voltage output value of the welding power supply.

[0047] The operation center circuit is used to perform PID operation on the digital signal of the analog-to-digital conversion circuit, and sum it with the constant current or constant voltage output setting value of the welding power supply, perform PID operation and slope compensation operation on the summation result, and transmit the operation result to the digital-to-analog conversion circuit DAC, and convert it into analog DAC output again.

[0048] The comparator circuit COMP compares the analog DAC output signal with the primary current sampling signal; the output comparison structure outputs a reset pulse signal when the analog DAC output is the same as the primary current, controls the PWM1 or PWM2 signal to turn off, and realizes the adjustment of the pulse width of the PWM1 and PWM2 signals.

[0049] The high-precision timer circuit HRTIM controls the PWM1 or PWM2 signal to be turned off when the reset pulse signal is generated according to the output of the comparator circuit, thereby adjusting the pulse width of the PWM1 and PWM2 signals.

[0050] The high-precision timer circuit includes a timer unit, three comparison units, and a first setting value unit. The input of the first comparison unit is respectively connected to the timer unit and the first setting value unit, and is used to compare the output of the timer unit with the first setting value. Its output is respectively connected to the second comparison unit and the second comparison unit; the second comparison unit is connected to the first comparison unit and the comparator circuit, and is used to output the PWM1 signal. The third comparison unit is connected to the first comparison unit and the comparator circuit, and is used to output the PWM2 signal, and the PWM1 signal and the PWM2 signal are push-pull mode signals. Specific embodiment three

[0052] The present application discloses a fully digital welding power supply current type control circuit, wherein the controller circuit adopts the circuit in the STM32G4 series chip.

[0053] The functions of the controller circuit are completed by using the high-precision timer circuit HRTIM, ADC circuit, DAC circuit, comparator COMP, and PID operation in the chip.

[0054] Using the high-precision timer circuit in the chip, at the beginning of the timing, PWM1 is set and ADC sampling is triggered. After the timing reaches the first set value, the PMW1 signal is reset. After the timing reaches the second set value, the timer returns to zero; the PWM2 signal is set. After the timing reaches the first set value, the PWM2 signal is reset. After the timing reaches the second set value, the timer returns to zero and the PWM1 signal is set again. By analogy, push-pull PWM1 and PWM2 signals are generated and transmitted to the drive circuit to control the conduction time of the power tube of the inverter full-bridge circuit.

[0055] The ADC circuit in the chip converts the analog signal output by the welding power supply into a digital signal, sums it with the constant output set value, and then goes through the PID algorithm and slope compensation operation, and is then converted into a slope analog signal by the DAC circuit in the chip.

[0056] Through MCU configuration, the comparator in the chip compares the decreasing ramp analog quantity with the increasing primary current, and outputs the comparison result to the high-precision timer circuit in the chip. When the primary current rises to the DAC setting value, the comparator will generate a reset pulse signal. By configuring the MCU, the comparator output signal can be sent to the HRTIM peripherals to turn off the PWM1 and PWM2 signals of the HRTIM peripherals in real time, and output the drive PWM1 and drive PWM2 signals to achieve the purpose of adjusting the PWM1 and PWM2 pulse widths.

[0057] The result of PID operation is ultimately used to control the peak value of the primary current of the welding power supply, which can achieve wave-by-wave limitation of the primary current, suppress the magnetic bias of the high-frequency transformer, and limit the peak current of power tubes such as IGBT or MOSFET in real time to ensure that it is within the appropriate range; and by using different feedback signals, the welding power supply output control and characteristic control can be achieved.

[0058] Control of STM32G4 series chips, such as Figure 3 As shown, the following steps are included:

[0059] S1, precision timer circuit generates PWM1, PWM2 signals, and triggers ADC sampling when PWM1 or PWM2 signal is set;

[0060] S2, after ADC sampling is completed, DMA transmission is triggered, and the current analog signal is converted into a current digital signal and then transmitted to the computing center;

[0061] S3, trigger DMA interrupt after DMA transfer is completed;

[0062] S4, perform power timing control, PID calculation, and update DAC output;

[0063] S5, the updated DAC output is subjected to slope compensation to obtain a decreasing slope analog signal, which is compared with the increasing primary current signal, and a reset pulse signal is output to adjust the pulse width of PWM1 and PWM2 signals;

[0064] S6, go to S1.

[0065] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fully digital welding power supply current type control method, characterized in that: include: Set a timer, set the PWM signal at the beginning of the timing, reset the PWM signal after the timing reaches the first set value, and output PWM1 and PWM2 signals in a push-pull manner to control the inverter output; Collect the welding power supply output signal and convert it into a digital signal. After PID algorithm and slope compensation, it is converted into a slope analog signal. In one cycle, when the decreasing slope analog quantity is equal to the increasing primary current, a reset pulse signal is output to adjust the PWM1 and PWM2 signal pulse widths to achieve output control of the welding power supply. Among them, at the beginning of the timing, the PWM signal is set, and after the timing reaches the first set value, the PWM signal is reset, and the PWM1 and PWM2 signals are output in a push-pull manner, specifically including: At the beginning of the timing, a cycle starts and the PWM1 signal is set; After the timing reaches the first set value, the PMW1 signal is reset and the timing continues; After the timing reaches the second set value, the timer returns to zero, the PWM2 signal is set, and the timing continues; After the timing reaches the first set value again, the PMW2 signal is reset and the timing continues; When the timing reaches the second set value again, it indicates that one cycle ends, the timer returns to zero, and the PWM1 signal is set.

2. The control method according to claim 1, characterized in that: After the timing reaches the first set value, the timing continues, and after reaching the second set value, the timer returns to zero; before the PWM1 or PWM2 signal starts, the PWM2 or PWM1 signal is turned off.

3. The control method according to claim 1, characterized in that: The slope of the ramp analog signal can be optimized and adjusted according to parameters. When the output current increases, the ramp analog signal moves up, and when the output current decreases, the ramp analog signal moves down.

4. A fully digital welding power supply current type control circuit using the fully digital welding power supply current type control method according to claim 1, characterized in that: It includes welding power supply circuit, feedback signal processing circuit, controller circuit, primary current signal processing circuit and driving circuit; Among them, one end of the feedback signal processing circuit, one end of the primary current signal processing circuit, and one end of the drive circuit are respectively connected to the welding power supply circuit, and at the same time, the other end of the feedback signal processing circuit, the other end of the primary current signal processing circuit, and the other end of the drive circuit are respectively connected to the controller circuit; The feedback signal processing circuit is used to collect the output size of the welding power supply; the primary current signal processing circuit is used to collect the primary current size; the controller circuit is used to generate push-pull PWM1 and PWM2 signals in a timing manner, convert the analog quantity of the welding power supply output into a digital signal, and then convert it into a ramp analog signal after PID algorithm processing and slope compensation. In the same cycle, the decreasing ramp analog quantity is compared with the increasing primary current, and a reset pulse signal is output according to the comparison result to control the pulse width of the PWM1 and PWM2 signals, thereby controlling the output of the welding power supply; The controller circuit is used to generate push-pull PWM1 and PWM2 signals in a timing manner, specifically including: At the beginning of the timing, a cycle starts and the PWM1 signal is set; After the timing reaches the first set value, the PMW1 signal is reset and the timing continues; After the timing reaches the second set value, the timer returns to zero, the PWM2 signal is set, and the timing continues; After the timing reaches the first set value again, the PMW2 signal is reset and the timing continues; When the timing reaches the second set value again, it indicates that one cycle ends, the timer returns to zero, and the PWM1 signal is set.

5. The control circuit according to claim 4, characterized in that: The welding power supply circuit includes a primary rectifier filter circuit, an inverter circuit, a high-frequency transformer circuit, and a secondary rectifier filter circuit connected in sequence. The feedback signal processing circuit is connected to the output of the secondary rectifier filter circuit and is used to collect the output size of the welding power supply. One end of the primary current signal processing circuit is connected to the output end of the inverter circuit and is used to collect the primary current. The drive circuit is connected to the inverter circuit and is used to control the output of the inverter circuit.

6. The control circuit according to claim 4, characterized in that: The controller circuit includes an analog-to-digital conversion circuit, an operation center circuit, a digital-to-analog conversion circuit, a comparator circuit, and a high-precision timer circuit connected in sequence; the operation center circuit is used to perform PID operation on the digital signal of the analog-to-digital conversion circuit; the digital-to-analog conversion circuit converts the operation result into an analog signal; the comparator circuit is used to compare the analog signal with the primary current sampling signal; The high-precision timer circuit controls the PWM signal according to the output of the comparator circuit.

7. The control circuit according to claim 6, characterized in that: The high-precision timer circuit includes a timer unit and three comparison units. The first comparison unit is connected to the timer unit and is used to compare the output of the timer unit with a set value. The second comparison unit is connected to the first comparison unit and the comparator circuit and is used to output a PWM1 signal. The third comparison unit is connected to the first comparison unit and the comparator circuit and is used to output a PWM2 signal. The PWM1 signal and the PWM2 signal are push-pull mode signals.

8. The control circuit according to claim 6, characterized in that: The controller circuit also includes a setting circuit, which is connected to the analog-to-digital conversion circuit and the operation center circuit, and is used to perform a sum or difference operation between the analog-to-digital conversion circuit and the set value, and then output it to the operation center.

9. The control circuit according to claim 4, characterized in that: The controller circuit adopts STM32G4 series chips and a high-precision timer circuit in the chip. When the timing starts, the PWM signal is set and the ADC sampling is triggered. After the timing reaches a first set value, the PWM signal is reset, and the PWM1 and PWM2 signals are output in a push-pull manner respectively to control the inverter output; the ADC circuit in the chip is used to convert the welding power supply output analog signal into a digital signal, which is summed with the constant output set value, and then converted into a ramp analog signal by the DAC circuit in the chip after the PID algorithm and slope compensation; the comparator in the chip compares the decreasing ramp analog quantity with the increasing primary current, outputs the comparison result to the high-precision timer circuit in the chip, and outputs a reset pulse signal when the ramp analog quantity is equal to the primary current, adjusts the pulse width of the PWM1 and PWM2 signals, and realizes the output control of the welding power supply through the driving circuit.

10. The control circuit according to claim 9, characterized in that: The control of the STM32G4 series chip includes the following steps: S1, high-precision timer circuit generates PWM1 and PWM2 signals, and triggers ADC sampling when PWM1 or PWM2 signal is set; S2, after ADC sampling is completed, DMA transmission is triggered, and the current analog signal is converted into a current digital signal and then transmitted to the computing center; S3, trigger DMA interrupt after DMA transfer is completed; S4, perform power timing control, PID calculation, and update DAC output; S5, the updated DAC output is subjected to slope compensation to obtain a decreasing slope analog signal, which is compared with the increasing primary current signal, and a reset pulse signal is output to adjust the pulse width of PWM1 and PWM2 signals; S6, go to S1.

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