Switching tube driving voltage control circuit and method and power converter

Abstract

The invention relates to a switching tube driving voltage control circuit and method and a power converter. The switch tube driving voltage control circuit in one aspect is used for being connected with each switch tube in the power converter and comprises a sampling circuit, a first feedback circuit, a power supply circuit and a driving circuit, and the first sampling circuit is used for sampling alternating current side voltage of a power conversion circuit to obtain target sampling voltage; the first feedback circuit is used for processing according to a first mapping relation based on the target sampling voltage to obtain a target feedback voltage; the power supply circuit is used for outputting target power supply voltage based on the target feedback voltage; and the driving circuit is used for outputting target driving voltage based on the target power supply voltage so as to drive conduction of the switching tube. By adopting the switching tube driving voltage control circuit, the conversion efficiency of the power converter can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of power conversion, and in particular to a switch tube drive voltage control circuit, method and power converter. Background Art

[0002] Power converters are power conversion devices used to convert electrical energy from one form to another to achieve energy transmission and control under different power requirements. The working principle of the power converter is to control the circuit to make the switch tube "on" and "off" continuously. When the switch tube pulse modulates the input voltage, power conversion such as DC-AC voltage conversion or DC-DC voltage conversion can be achieved.

[0003] In the related art, the amplitude of the driving voltage for turning on the gate of the switch tube is fixed, resulting in a low conversion efficiency of the power converter. Summary of the invention

[0004] Based on this, it is necessary to provide a switch tube drive voltage control circuit, method and power converter that can improve the conversion efficiency of the power converter in order to address the above technical problems.

[0005] In a first aspect, the present application provides a switch tube drive voltage control circuit, which is used to connect to each switch tube in a power converter. The switch tube drive voltage control circuit includes: a first sampling circuit, a first feedback circuit, a power supply circuit and a drive circuit, wherein:

[0006] The first sampling circuit is used to sample the AC side voltage of the power conversion circuit to obtain a target sampling voltage;

[0007] The first feedback circuit is used to process the target sampling voltage according to the first mapping relationship to obtain the target feedback voltage, wherein the first mapping relationship includes that the amplitude of the feedback voltage corresponding to the first sampling voltage is not greater than the amplitude of the feedback voltage corresponding to the second sampling voltage, and the amplitude of the first sampling voltage is greater than the amplitude of the second sampling voltage;

[0008] The power supply circuit is used to output a target power supply voltage based on the target feedback voltage, and the relationship between the amplitude of the target power supply voltage and the amplitude of the target feedback voltage is negatively correlated;

[0009] The driving circuit is used to output a target driving voltage based on a target power supply voltage to drive the switch tube to be turned on, wherein the switching frequency of the switch tube varies with the amplitude of the AC side voltage.

[0010] In one embodiment, the first feedback circuit includes:

[0011] A first microcontroller, wherein an input end of the first microcontroller is connected to an output end of the sampling circuit, and an output end of the first microcontroller is connected to a feedback input end of the power supply circuit.

[0012] In one embodiment, the output of the first microcontroller includes a digital-to-analog output of the first microcontroller;

[0013] The first microcontroller is used to process the target sampling voltage according to the first mapping relationship and output the target feedback voltage through the digital-to-analog output terminal.

[0014] In one embodiment, the output end of the first microcontroller includes a duty cycle output end; the feedback circuit further includes a first filter circuit, the input end of the first filter circuit is connected to the duty cycle output end, and the output end of the first filter circuit is connected to the feedback input end of the power supply circuit;

[0015] The first microcontroller is used to process the target sampling voltage according to the first mapping relationship and output a first duty cycle voltage through the duty cycle output terminal;

[0016] The first filter circuit is used to filter the first duty cycle voltage to obtain a target feedback voltage.

[0017] In one embodiment, the first mapping relationship includes a linear relationship between the amplitude of the feedback voltage and the amplitude of the sampling voltage.

[0018] In one embodiment, the first mapping relationship includes a nonlinear relationship between the amplitude of the feedback voltage and the amplitude of the sampling voltage.

[0019] In one embodiment, the first feedback circuit includes a rectifier circuit and a second filter circuit, wherein:

[0020] The rectifier circuit is used to rectify and phase-shift the target sampling voltage to obtain a rectified voltage;

[0021] The second filter circuit is used to filter and amplify the rectified voltage to obtain a target feedback voltage.

[0022] In one embodiment, the power supply circuit includes an auxiliary source chip, a first resistor, a second resistor and a third resistor; wherein,

[0023] The output end of the auxiliary source chip is connected to the first end of the first resistor, and the feedback input end of the auxiliary source chip is connected to the second end of the first resistor, the first end of the second resistor, and the first end of the third resistor;

[0024] A second end of the second resistor is grounded;

[0025] The second end of the third resistor is connected to the output end of the feedback circuit.

[0026] In a second aspect, the present application provides a switch tube drive voltage control circuit, which is used to connect to each switch tube in a power conversion circuit. The switch tube drive voltage control circuit includes: a second feedback circuit, a power supply circuit and a drive circuit, wherein:

[0027] The second feedback circuit is used to obtain the target switching frequency of the switch tube, and process according to the target switching frequency according to the second mapping relationship to obtain the target feedback voltage, wherein the second mapping relationship includes that the amplitude of the feedback voltage corresponding to the first switching frequency is not less than the amplitude of the feedback voltage corresponding to the second switching frequency, and the first switching frequency is greater than the second switching frequency;

[0028] The power supply circuit is used to output a target power supply voltage based on the target feedback voltage, and the relationship between the amplitude of the target power supply voltage and the amplitude of the target feedback voltage is negatively correlated;

[0029] The driving circuit is used to output a target driving voltage based on a target power supply voltage to drive the switch tube to conduct, wherein the switching frequency of the switch tube varies with the amplitude of the voltage on the AC side of the power conversion circuit.

[0030] In one embodiment, the second feedback circuit includes a programmable logic device and a third filter circuit, the output end of the third filter circuit is connected to the digital output end of the programmable logic device, and the output end of the third filter circuit is connected to the feedback input end of the power supply circuit; wherein,

[0031] The programmable logic device is used to obtain the target switching frequency, and process according to the target switching frequency according to the second mapping relationship, and output the second duty cycle voltage through the digital output terminal;

[0032] The third filter circuit is used to filter the second duty cycle voltage to obtain a target feedback voltage.

[0033] In a third aspect, the present application further provides a method for controlling a switch tube driving voltage, comprising:

[0034] Obtaining a target sampling voltage corresponding to an AC side voltage of a power conversion circuit;

[0035] Mapping the target sampling voltage according to a first mapping relationship to obtain a target feedback voltage, wherein the first mapping relationship includes that the amplitude of the feedback voltage corresponding to the first sampling voltage is not greater than the amplitude of the feedback voltage corresponding to the second sampling voltage, and the amplitude of the first sampling voltage is greater than the amplitude of the second sampling voltage;

[0036] Among them, the target feedback voltage is used to determine the target driving voltage for driving the switch tube to conduct based on the target feedback voltage. The relationship between the amplitude of the target driving voltage and the amplitude of the target feedback voltage is negatively correlated, and the switching frequency of the switch tube changes with the amplitude of the AC side voltage.

[0037] In a fourth aspect, the present application further provides a switch tube driving voltage control method, comprising:

[0038] Obtaining a target switching frequency of a power conversion circuit switch tube;

[0039] The target switching frequency is processed according to a second mapping relationship to obtain a target feedback voltage, wherein the second mapping relationship includes that the amplitude of the feedback voltage corresponding to the first switching frequency is not less than the amplitude of the feedback voltage corresponding to the second switching frequency, and the first switching frequency is greater than the second switching frequency;

[0040] Among them, the target feedback voltage is used to determine the target driving voltage for driving the switch tube to conduct based on the target feedback voltage. The relationship between the amplitude of the target driving voltage and the amplitude of the target feedback voltage is negatively correlated, and the switching frequency of the switch tube changes with the amplitude of the AC side voltage of the power conversion circuit.

[0041] In a fifth aspect, the present application further provides a power converter, the power converter comprising the switch tube drive voltage control circuit and the power conversion circuit of the first aspect or the second aspect;

[0042] The switch tube driving voltage control circuit is connected to the driving end of each switch tube in the power conversion circuit.

[0043] The switch tube drive voltage control circuit, method and power converter provided above, in one aspect, the switch tube drive voltage control circuit is used to connect to each switch tube in the power conversion circuit, including: a first sampling circuit, a first feedback circuit, a power supply circuit and a drive circuit, wherein the first sampling circuit is used to sample and process the AC side voltage of the power conversion circuit to obtain a target sampling voltage; the first feedback circuit is used to process according to a first mapping relationship based on the target sampling voltage to obtain a target feedback voltage, wherein the first mapping relationship includes that the amplitude of the feedback voltage corresponding to the first sampling voltage is not greater than the amplitude of the feedback voltage corresponding to the second sampling voltage, and the amplitude of the first sampling voltage is greater than the amplitude of the second sampling voltage; the power supply circuit is used to output a target power supply voltage based on the target feedback voltage, and the relationship between the amplitude of the target power supply voltage and the amplitude of the target feedback voltage is negatively correlated; the drive circuit Used to output a target driving voltage based on a target power supply voltage to drive the conduction of a switch tube, wherein the switching frequency of the switch tube varies with the amplitude of the AC side voltage; in this way, by sampling the AC side voltage of the power conversion circuit, a first processing is performed through the first feedback circuit to obtain a feedback voltage that is negatively correlated with the first sampling voltage as a whole, and then a power supply circuit with a feedback voltage control function is used to perform a second processing based on the target feedback voltage to obtain a target power supply voltage that is negatively correlated with the target feedback voltage. In this way, a positive correlation between the AC side voltage amplitudes of the drive circuit and the power conversion circuit is established through the first sampling circuit, the first feedback circuit and the power supply circuit, so that the target driving voltage output by the drive circuit for driving the switch tube can be dynamically adjusted following the positive correlation of the AC side voltage amplitude, dynamically reducing the driving loss and the conduction loss, and improving the conversion efficiency of the power converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] FIG1 is a block diagram of a switch drive voltage control circuit according to an embodiment;

[0046] Figure 2 is a structural block diagram of a switch driving voltage control circuit in another embodiment;

[0047] Figure 3 is a structural block diagram of a switch driving voltage control circuit in another embodiment;

[0048] Figure 4 is an exemplary schematic diagram of voltage waveforms of an AC side voltage and a driving voltage in one embodiment;

[0049] Figure 5 is an exemplary schematic diagram of voltage waveforms of an AC side voltage, a feedback voltage, and a driving voltage in one embodiment;

[0050] Figure 6 is a structural block diagram of a switch driving voltage control circuit in another embodiment;

[0051] Figure 7 is a structural block diagram of a switch driving voltage control circuit in another embodiment;

[0052] Figure 8 is a structural block diagram of a switch driving voltage control circuit in another embodiment;

[0053] Fig. 9 1 is a flow chart of a switch driving voltage control method according to an embodiment;

[0054] Fig.10 is a flow chart of a switch driving voltage control method according to another embodiment;

[0055] Fig.11 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0058] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0059] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0060] It is understood that the term "based on" used in this application is used to describe one or more factors that affect the determination, and does not exclude other factors that may affect the determination. For example, the phrase "determine A based on B" means that the determination of A can be based entirely or at least partially on factor B, that is, B is a factor that affects the determination of A, but does not exclude that the determination of A is also based on C.

[0061] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0062] The switch drive voltage control circuit provided in the embodiment of the present application is used in a power converter in which the switch tube is actively driven. Exemplarily, the power converter is a DC-AC converter using a dual active bridge (DAB) topology. Among them, the DC-AC converter of DAB is a power conversion topology with a dual active bridge, including eight power tubes, of which four switch tubes form a full-bridge circuit on the DC side, and the other four switch tubes form a half-bridge circuit on the AC side.

[0063] Among them, the switching tube can also be called a power tube; the switching tube involved in the embodiment of the present application is a voltage-driven switching tube, including but not limited to MOS tube (Metal-Oxide-Semiconductor Field-Effect Transistor) and IGBT (Insulated Gate Bipolar Transistor).

[0064] The principle on which the switch tube driving voltage control circuit provided in this embodiment is based is first introduced to facilitate a clear understanding of this solution.

[0065] Taking MOS tube as an example, the gate drive voltage reaches the turn-on threshold of the MOS tube to turn on the MOS tube. Within the tolerance range of the MOS tube, the higher the gate drive voltage, the smaller the on-resistance of the MOS tube, and the smaller the corresponding conduction loss of the MOS tube. However, a higher drive voltage also requires the drive circuit of the MOS tube to provide more energy, and the corresponding drive loss of the MOS tube is greater. After a large number of experimental studies, the applicant found that the conduction loss of the MOS tube is more obvious when the output power of the power converter is greater (i.e., the output current), and the drive loss is more obvious when the switching frequency is higher.

[0066] In the power converter of the actively driven switch tube, the control logic of the power converter determines that: the greater the voltage amplitude on the AC side, the greater the instantaneous power of the power converter, and the smaller the switching frequency of the switch tube; when the AC side voltage is near the peak point, the output power of the power converter is high, and the switching frequency of the MOS tube is low; when the AC side voltage is near the zero point, the output power of the power converter is low, and the switching frequency of the MOS tube is high; taking the micro inverter based on the DAB topology in the grid-connected working state as an example, near the peak point of the grid voltage, the switching frequency of each MOS tube in the micro inverter is low, and the output power of the power converter is high; near the zero point of the grid voltage, the switching frequency of each MOS tube in the inverter is high, and the output power of the power converter is low; that is, within an AC cycle, the switching frequency of the MOS tube is negatively correlated with the absolute value of the AC side voltage, and the working current of the MOS tube is positively correlated with the absolute value of the AC side voltage.

[0067] Based on this, the present application provides a switch tube driving voltage control circuit through the following embodiments, which increases the driving voltage when the amplitude of the AC side voltage is high. At this time, the switching frequency of the MOS tube is low and the driving loss is not obvious, and the conduction current is high and the conduction loss is more obvious. Combined with the fact that the higher the driving voltage, the smaller the conduction loss and the greater the driving loss, the MOS tube has a smaller overall loss at this time, and the power converter efficiency is higher; when the amplitude of the AC side voltage is low, the driving voltage is reduced. At this time, the switching frequency of the MOS tube is high and the driving loss is more obvious, and the conduction current is small and the conduction loss is not obvious. Combined with the characteristics that the lower the driving voltage, the greater the conduction loss and the smaller the driving loss, the MOS tube has a smaller overall loss at this time, and the power converter efficiency is higher; in this way, the conduction loss and driving loss of the MOS tube are dynamically reduced, the overall loss of the power conversion circuit is reduced, and ultimately the efficiency of the power converter is improved.

[0068] In an exemplary embodiment, a switch tube driving voltage control circuit 100 is provided for connecting to each switch tube in a power conversion circuit. Referring to FIG. 1 , the switch tube driving voltage control circuit 100 includes a first sampling circuit 110 , a first feedback circuit 120 , a power supply circuit 130 and a driving circuit 140 .

[0069] The first sampling circuit 110 is used to sample the AC side voltage of the power conversion circuit to obtain a target sampling voltage.

[0070] Exemplarily, the AC side of the power converter can be connected to a power grid, and the voltage on the AC side is the power grid voltage; exemplary, the AC side of the power converter can also be connected to an AC load, and the voltage on the AC side is the load voltage.

[0071] Exemplarily, the first sampling circuit 110 may be a current transformer and a resistor, which is used to sample the AC side current at a ratio of 1:N, and then convert it into a target sampling voltage through the resistor. Where N is the transformation ratio of the current transformer. Also exemplary, the first sampling circuit 110 may include a voltage sampling chip.

[0072] The first feedback circuit 120 is used to process the target sampling voltage according to the first mapping relationship to obtain the target feedback voltage. The first mapping relationship includes that the amplitude of the feedback voltage corresponding to the first sampling voltage is not greater than the amplitude of the feedback voltage corresponding to the second sampling voltage, and the amplitude of the first sampling voltage is greater than the amplitude of the second sampling voltage; the power supply circuit 130 is used to output the target power supply voltage based on the target feedback voltage; the relationship between the amplitude of the target power supply voltage and the amplitude of the target feedback voltage is negatively correlated. The drive circuit 140 is used to output the target drive voltage based on the target power supply voltage to drive the conduction of the switch tube, wherein the switching frequency of the switch tube changes with the amplitude of the AC side voltage. Specifically, the larger the amplitude of the AC side voltage, the larger the instantaneous power of the power conversion circuit and the smaller the switching frequency. The drive circuit 140 is connected to the power conversion circuit 200 in the power converter to provide a drive voltage for each switch tube in the power conversion circuit 200. Exemplarily, the power conversion circuit 200 is a DAB topology circuit.

[0073] Exemplarily, the driving circuit 140 may be connected to a programmable logic device in a power converter to control the switching frequency of each switch tube.

[0074] The input end of the first feedback circuit 120 is connected to the first sampling circuit 110 , and the output end of the first feedback circuit 120 is connected to the feedback input end of the power circuit 130 , so that the power circuit 130 can adjust the output voltage of the power circuit 130 based on the output of the first feedback circuit 120 .

[0075] Among them, the target feedback voltage is obtained by processing the target sampling voltage according to the first mapping relationship, and the change trends between the target feedback voltage and the target sampling voltage are opposite, that is, the larger the amplitude of the sampling voltage, the smaller the amplitude of the feedback voltage. The relationship between the amplitude of the target power supply voltage and the amplitude of the target feedback voltage is negatively correlated, that is, the smaller the target feedback voltage, the larger the target power supply voltage; in this way, after the first feedback circuit 120 and the power supply circuit 130, the amplitude of the target power supply voltage input to the driving circuit 140 is positively correlated with the amplitude of the target sampling voltage, so that the amplitude of the target driving voltage output by the driving circuit 140 to the switch tube is positively correlated with the amplitude of the target sampling voltage, so that when the amplitude of the AC side voltage is large, the driving voltage of the switch tube is large, and when the amplitude of the AC side voltage is small, the driving voltage of the switch tube is low, and the conduction loss and driving loss of the MOS tube are dynamically reduced.

[0076] The first sampling voltage and the second sampling voltage refer to any two voltages with different amplitudes that can be output by the first sampling circuit 110, the first sampling voltage refers to a sampling voltage with a larger amplitude, and the second sampling voltage refers to a sampling voltage with a smaller amplitude. The first sampling voltage and the second sampling voltage in the embodiment of the present application are used to illustrate the mapping relationship between the sampling voltage and the feedback voltage included in the first mapping relationship.

[0077] In a possible implementation, the first mapping relationship includes a linear relationship between the amplitude of the feedback voltage and the amplitude of the sampling voltage. In this implementation, the first mapping relationship includes that the amplitude of the feedback voltage corresponding to the first sampling voltage is smaller than the amplitude of the feedback voltage corresponding to the second sampling voltage, and the amplitude of the first sampling voltage is larger than the amplitude of the second sampling voltage, that is, the first mapping relationship means that the larger the sampling voltage, the smaller the amplitude of the feedback voltage.

[0078] Exemplarily, the first mapping relationship is V o =AB*|V ac |, where V o Represents the feedback voltage, V ac Indicates the sampling voltage, A and B are pre-set mapping parameters. For example, A=2.35, B=0.00163; the mapping parameters A and B in this example are obtained by the applicant based on the hardware parameters of the power circuit used in the test and the electrical characteristics of the switch tube and the actual test results. They are not intended to limit the mapping parameters. It is understandable that those skilled in the art can determine the mapping parameters by debugging based on specific implementation conditions including but not limited to the hardware parameters of the power circuit and / or the electrical characteristics of the switch tube.

[0079] In a possible implementation, the first mapping relationship includes a nonlinear relationship between the amplitude of the feedback voltage and the amplitude of the sampling voltage. In this implementation, the amplitude of the sampling voltage is divided into multiple amplitude intervals, each amplitude interval corresponds to a different feedback voltage, and the sampling voltages in the same amplitude interval correspond to the same feedback voltage; the sampling voltage and the feedback voltage are negatively correlated as a whole. Exemplarily, the first mapping relationship includes a piecewise function. In another exemplary embodiment, the first mapping relationship includes a list mapping relationship.

[0080] In one possible implementation, the first feedback circuit 120 is implemented by a pure hardware circuit. In another possible implementation, the first feedback circuit 120 includes a first microcontroller 121, that is, implemented by combining software and hardware. The full name of the microcontroller is Microcontroller Unit, or MCU for short.

[0081] The power supply circuit 130 adjusts the output power supply voltage according to the input feedback voltage, wherein the larger the amplitude of the input feedback voltage is, the smaller the amplitude of the output power supply voltage is, and the smaller the amplitude of the input feedback voltage is, the smaller the amplitude of the output power supply voltage is. The power supply voltage refers to the power supply voltage of the input drive circuit 140.

[0082] In one possible implementation, please refer to Figure 2 and Figure 3 The power supply circuit 130 includes an auxiliary power chip 131 with voltage feedback characteristics and a peripheral circuit corresponding to the auxiliary power chip 131. Figure 2 and Figure 3 In, V out is the power supply voltage output by the power supply circuit 130, V o Refers to the feedback voltage, and FB refers to the feedback pin of the auxiliary source chip 131. Please refer to Figure 2 and Figure 3 The peripheral circuit includes a first resistor R1, a second resistor R2 and a third resistor R FB The output end of the auxiliary source chip 131 is connected to the first end of the first resistor R1, and the feedback input end of the auxiliary source chip 131 is connected to the second end of the first resistor R1, the first end of the second resistor R2 and the third resistor R FB A first end of the second resistor R2 is connected to a first end of the first feedback circuit 120, a second end of the second resistor R2 is grounded, and a second end of the third resistor R3 is connected to an output end of the first feedback circuit 120.

[0083] The power supply voltage V output by the power supply circuit 130 out Under the regulation of the feedback pin voltage, the gate drive voltage can be provided to the MOS tube through the drive circuit 140 .

[0084] Exemplarily, the auxiliary power chip 131 is a BUCK (step-down) power chip.

[0085] The switch tube driving voltage control circuit 100 provided in the above embodiment is used to connect to each switch tube in the power converter, and includes: a first sampling circuit 110, a first feedback circuit 120, a power supply circuit 130 and a drive circuit 140, wherein the first sampling circuit 110 is used to sample and process the AC side voltage of the power conversion circuit to obtain a target sampling voltage; the first feedback circuit 120 is used to process according to a first mapping relationship based on the target sampling voltage to obtain a target feedback voltage, wherein the first mapping relationship includes that the amplitude of the feedback voltage corresponding to the first sampling voltage is not greater than the amplitude of the feedback voltage corresponding to the second sampling voltage, and the amplitude of the first sampling voltage is greater than the amplitude of the second sampling voltage; the power supply circuit 130 is used to output a target power supply voltage based on the target feedback voltage, and the relationship between the amplitude of the target power supply voltage and the amplitude of the target feedback voltage is negatively correlated; the drive circuit 140 is used to output a target power supply voltage based on the target voltage. Source voltage, output target driving voltage to drive the conduction of the switch tube, wherein the switching frequency of the switch tube varies with the amplitude of the AC side voltage; in this way, by sampling the AC side voltage of the power conversion circuit, the first feedback circuit 120 performs the first processing to obtain a feedback voltage that is negatively correlated with the sampled voltage as a whole, and then the power supply circuit 130 with a feedback voltage control function performs the second processing based on the target feedback voltage to obtain a target power supply voltage that is negatively correlated with the target feedback voltage. In this way, a positive correlation between the driving voltage and the AC side voltage amplitude of the power conversion circuit is established through the first sampling circuit 110, the first feedback circuit 120 and the power supply circuit 130, so that the target driving voltage output by the driving circuit 140 for driving the switch tube can be dynamically adjusted following the positive correlation of the AC side voltage amplitude, dynamically reducing the driving loss and the conduction loss, and improving the conversion efficiency of the power converter.

[0086] For example, the switch tube driving voltage control circuit 100 provided in the above embodiment is applied to the micro inverter grid-connected operation process based on the DAB topology structure, please refer to Figure 4 At the peak point A of the grid voltage, the switching frequency of the switch tube is low, the output current is large, and the conduction loss accounts for the main factor. The driving voltage is increased to reduce the conduction loss. At the zero-crossing point B of the grid voltage, the switching frequency of the MOS tube is high, the output current of the micro inverter is small, and the driving loss accounts for the main factor. The driving voltage is reduced to reduce the driving loss.

[0087] Please refer to Figure 5 , is an exemplary schematic diagram of the variation trend between the AC side voltage, the feedback voltage and the drive voltage. When the first mapping relationship is a nonlinear relationship, the waveforms of the feedback voltage and the drive voltage may be step-shaped, and the variation trend of the feedback voltage is opposite to the variation trend of the amplitude of the AC side voltage.

[0088] In an exemplary embodiment, please refer to Figure 2 and Figure 3 , based on the embodiment shown in FIG. 1 , the first feedback circuit 120 in the switch tube driving voltage control circuit 100 provided includes a first microcontroller 121. The input end of the first microcontroller 121 is connected to the output end of the first sampling circuit 110, and the output end of the first microcontroller 121 is connected to the feedback input end of the power supply circuit 130.

[0089] In one possible implementation, please refer to Figure 2 The output end of the first microcontroller 121 includes a digital-to-analog output end of the first microcontroller 121, namely a DA (Digital-to-Analog) pin. In this embodiment, the first microcontroller 121 is used to process the target sampling voltage according to the first mapping relationship and output the target feedback voltage through the digital-to-analog output end. The target feedback voltage is an analog signal.

[0090] In this implementation, the DA pin on the first microcontroller 121 is used to directly output the target feedback voltage in the form of an analog signal, without the need for an additional filtering circuit, with low hardware cost and simple circuit topology.

[0091] In one possible implementation, please refer to Figure 3 , the output end of the first microcontroller 121 includes a duty cycle output end, and the first feedback circuit 120 also includes a first filter circuit. The input end of the first filter circuit is connected to the duty cycle output end, and the output end of the first filter circuit is connected to the input end of the first feedback circuit 120. The first microcontroller 121 is used to process the target sampling voltage according to the first mapping relationship and output the first duty cycle voltage through the duty cycle output end; the first filter circuit is used to filter the first duty cycle voltage to obtain the target feedback voltage.

[0092] For example, please refer to Figure 3 , the first filtering circuit includes an RC (resistance and capacitance) filtering circuit. Figure 3 As shown, the first filtering circuit includes a resistor R3 and a capacitor C1.

[0093] Exemplarily, the duty cycle output terminal of the first microcontroller 121 may be a general purpose input output (GPIO) pin of the first microcontroller 121. Also exemplary, the duty cycle output terminal of the first microcontroller 121 may be a PWM (Pulse Width Modulator) output pin of the first microcontroller 121, such as Figure 3 shown.

[0094] The first duty cycle voltage outputted from the duty cycle output terminal is in the form of a PWM wave, that is, in the form of a digital signal, which is converted into a target feedback voltage in the form of an analog signal by a first filtering circuit.

[0095] In this embodiment, the duty cycle output terminal of the first microcontroller 121 is used to first output a first duty cycle voltage in a digital form, and then the first filter circuit is used to filter the first duty cycle voltage into an analog target feedback voltage. This can reduce the resource usage of the first microcontroller 121 and avoid insufficient DA pin resources on the first microcontroller 121. Furthermore, the switch tube drive voltage control circuit 100 provided in this embodiment can be implemented in a first microcontroller 121 that does not have a DA pin, thereby improving the flexibility of the solution application.

[0096] The switch tube drive voltage control circuit 100 provided in the above embodiment implements the first feedback circuit 120 based on the first microcontroller 121. The first microcontroller 121 can read the real-time status of the AC side voltage of the power converter through the first sampling circuit 110, and is connected to the feedback input terminal of the power supply circuit 130 to inject feedback voltage into the power supply circuit 130 to adjust the power supply voltage output by the power supply circuit 130. This embodiment realizes the mapping of the sampling voltage to the feedback voltage through the first microcontroller 121 combined with software, with high accuracy. The specific parameters in the first mapping relationship can be flexibly adjusted according to the hardware parameters of the switch tube of the power conversion part in the power converter or the hardware parameters corresponding to the power supply circuit 130. The switch tube drive voltage control circuit 100 provided in this embodiment has good scalability.

[0097] In a possible implementation of this embodiment, the first microcontroller 121 can automatically adjust the target driving voltage to find the highest efficiency point. For example, based on the waveform of the target power supply voltage currently output by the driving circuit 140, a corresponding closed-loop control algorithm is set in the first microcontroller 121 to calculate the current efficiency of the power converter so that the driving voltage is within a safe range and the optimal target driving voltage is found by itself; for example, the target power supply voltage can be adjusted to the first microcontroller 121. Figure 4 The maximum and minimum amplitudes of the driving voltage waveform in .

[0098] In a possible implementation of the present embodiment, the first mapping relationship includes a first mapping relationship A and a first mapping relationship B, which correspond to different switch tubes respectively. It can be understood that the mapping parameters in the first mapping relationship A and the first mapping relationship B are determined based on the electrical characteristics of different switch tubes; the first feedback circuit 120 based on the first microcontroller 121 can determine to switch the mapping relationship currently required to be used from the first mapping relationship A and the first mapping relationship B based on the characteristics of the AC side voltage; or, the first feedback circuit 120 based on the first microcontroller 121 can switch the mapping relationship currently to be used in response to user input; further, the first mapping relationship can include multiple different first mapping relationships, and the first microcontroller 121 is used to switch the required mapping relationship in specific use, thereby improving the scalability of the switch tube driving voltage circuit.

[0099] In a possible implementation of this embodiment, the first microcontroller 121 is also used to obtain the target feedback voltage based on the target sampling voltage according to the first mapping relationship, and specifically to obtain the initial feedback voltage based on the target sampling voltage and the first mapping relationship. If the amplitude of the initial feedback voltage is greater than or equal to the preset feedback voltage threshold, the initial feedback voltage is used as the target feedback voltage. If the initial feedback voltage is greater than the preset feedback voltage threshold, the target feedback voltage is obtained based on the preset feedback voltage threshold. In this way, when the AC side voltage increases abnormally, such as when the grid voltage experiences a high penetration or cumulative surge, the target feedback voltage output by the first feedback circuit 120 will not be too small, and the target power supply voltage output by the power supply circuit 130 will not be too large, which is equivalent to setting an upper limit for the driving voltage of the switch tube, thereby improving the safety of the circuit operation.

[0100] In an exemplary embodiment, please refer to Figure 6 The first feedback circuit 120 in the provided switch drive voltage control circuit includes a rectifier circuit 122 and a second filter circuit 123, wherein the rectifier circuit 122 is used to rectify and phase-shift the target sampling voltage to obtain a rectified voltage; the second filter circuit 123 is used to filter and amplify the rectified voltage to obtain a target feedback voltage.

[0101] Exemplarily, the rectifier circuit 122 includes a full-bridge rectifier circuit consisting of four diodes and a phase shift circuit.

[0102] Among them, the full-bridge rectifier circuit obtains a waveform with the same amplitude change as the AC side voltage by rectifying the target sampling voltage. In order to obtain a rectified voltage with a changing trend opposite to that of the AC side voltage, the phase shifter circuit shifts the phase of the rectified voltage by 180°, or an integer multiple of 180°.

[0103] Exemplarily, the second filter circuit 123 includes an RC filter circuit and an amplifier circuit, wherein the RC filter circuit performs filtering and smoothing processing on the sorted voltage to obtain a filtered voltage of an analog signal waveform, and the amplifier circuit performs amplification processing on the filtered voltage, adjusts the amplitude of the filtered voltage, and obtains a target feedback voltage determined by the first mapping relationship. Among them, the amplification factor of the amplifier circuit can be greater than 1 or less than 1. Exemplarily, the amplification factor can be determined according to the electrical parameter characteristics of the auxiliary source chip, the rectifier circuit 122, and the switch tube used in the power supply circuit 130.

[0104] In a possible implementation, the rectifier circuit 122 includes not only a full-bridge rectifier circuit and a phase shift circuit, but also an isolation circuit, wherein the input end of the isolation circuit is connected to the output end of the first sampling circuit 110, and the output end of the isolation circuit is connected to the full-bridge rectifier circuit. Exemplarily, the isolation circuit includes two inverters connected in sequence.

[0105] In this implementation, the use of an isolation circuit can prevent related interference between the first sampling circuit 110 and the rectifier circuit 122, thereby improving the reliability of the switch drive voltage control circuit.

[0106] In an exemplary embodiment, the first feedback circuit 120 includes a step-down circuit, a rectifier circuit, and a filter circuit. The voltage amplitude on the AC side of the power converter is generally 0V-390V, which is relatively large. In this embodiment, the sampled target AC voltage is firstly stepped down by the step-down circuit to obtain a stepped-down voltage, and then rectified, phase-shifted, and filtered.

[0107] In an exemplary embodiment, please refer to Figure 7 , a switch tube driving voltage control circuit 300 is provided for connecting to each switch tube in the power converter circuit 200. Figure 7 As shown, the switch tube drive voltage control circuit 300 includes a second feedback circuit 310, a power circuit 130 and a drive circuit 140. It can be understood that the switch tube drive voltage control circuit 300 provided in this embodiment and the switch tube drive voltage control circuit 300 provided in the previous embodiment use different feedback circuit topologies, and the same power circuit topologies and drive circuit topologies.

[0108] Among them, the second feedback circuit 310 is used to obtain the target switching frequency of the switch tube, and processes according to the target switching frequency according to the second mapping relationship to obtain the target feedback voltage; the second mapping relationship includes that the amplitude of the feedback voltage corresponding to the first switching frequency is not less than the amplitude of the feedback voltage corresponding to the second switching frequency, and the first switching frequency is greater than the second switching frequency. Among them, the switching frequency of the switch tube varies with the amplitude of the AC side voltage of the power conversion circuit. Specifically, the larger the amplitude of the AC side voltage, the larger the instantaneous power of the power conversion circuit, and the smaller the switching frequency. The power supply circuit 130 is used to output the target power supply voltage based on the target feedback voltage, and the relationship between the amplitude of the target power supply voltage and the amplitude of the target feedback voltage is negatively correlated. The drive circuit 140 is used to output the target drive voltage based on the target power supply voltage to drive the switch tube to conduct.

[0109] In a possible implementation, the second mapping relationship includes a linear relationship between the switching frequency and the amplitude of the sampling voltage. In this implementation, the second mapping relationship includes that the amplitude of the feedback voltage corresponding to the first switching frequency is greater than the amplitude of the feedback voltage corresponding to the second switching frequency, that is, the second mapping relationship means that the lower the switching frequency, the smaller the amplitude of the feedback voltage.

[0110] In one possible implementation, the second mapping relationship includes a nonlinear relationship between the switching frequency and the amplitude of the sampled voltage. In this implementation, the switching frequency is divided into multiple frequency intervals according to the numerical value, each frequency interval corresponds to a different feedback voltage, and the switching frequency in the same frequency interval corresponds to the same feedback voltage. In this implementation, there is a situation where the switching frequency changes while the amplitude of the feedback voltage remains unchanged. Overall, the switching frequency and the feedback voltage are positively correlated. Exemplarily, the second mapping relationship includes a piecewise function; and again exemplary, the second mapping relationship includes a list mapping relationship.

[0111] The switching frequency of each switch tube in the power conversion circuit 200 in this embodiment varies with the amplitude of the AC side voltage of the power conversion circuit, wherein, when the amplitude of the AC side voltage is large, the switching frequency of the switch tube is low, such as near the peak value of the AC side voltage, the switching frequency of the switch tube is the lowest; when the amplitude of the AC side voltage is small, the switching frequency of the switch tube is high, such as near the zero point of the AC side voltage, the switching frequency of the switch tube is the highest; based on this, this embodiment directly adjusts the amplitude of the driving voltage of the switch tube according to the switching frequency of the switch tube, that is, the second feedback circuit 310 directly obtains the switching frequency for controlling the switch tube, and outputs the feedback voltage according to the switching frequency, and adjusts the power supply voltage output by the power supply circuit 130, so that the driving voltage The driving voltage output by the circuit 140 changes with the switching frequency of the switching tube; wherein, the switching frequency is processed for the first time by the second feedback circuit 310 to obtain a feedback voltage that is positively correlated with the switching frequency, and then a power supply circuit 130 with a feedback voltage control function is used to perform a second processing based on the feedback voltage to obtain a power supply voltage that is negatively correlated with the feedback voltage. A negative correlation is established between the driving voltage and the switching frequency of the switching tube of the power conversion circuit through the second feedback circuit 310 and the power supply circuit 130, so that the target driving voltage output by the driving circuit 140 for driving the switching tube can be dynamically adjusted with the negative correlation of the switching frequency of the switching tube, dynamically reducing the driving loss and conduction loss, and improving the conversion efficiency of the power converter.

[0112] In an exemplary embodiment, based on Figure 7 For the examples shown, please refer to Figure 8 The second feedback circuit includes an editable logic device 311 and a third filter circuit; the output end of the third filter circuit is connected to the digital output end of the programmable logic device, and the output end of the third filter circuit is connected to the feedback input end of the power supply circuit 130.

[0113] The programmable logic device 311 is used to obtain the target switching frequency, and process the target switching frequency according to the second mapping relationship, and output the second duty cycle voltage through the digital output terminal. The programmable logic device 311 is also used to process the AC side voltage of the power conversion circuit to obtain the switching frequency of the switch tube.

[0114] Exemplarily, the programmable logic device 311 is implemented by a CPLD (Complex Programmable Logic Device) or another exemplary embodiment, the programmable logic device 311 is implemented by a FPGA (Field Programmable Gate Array).

[0115] In one possible implementation, please refer to Figure 8The input end of the programmable logic device 311 is used to connect to the output end of the second microcontroller 410, the input end of the second microcontroller 410 is connected to the output end of the second sampling circuit 420, the input end of the second sampling circuit 420 is connected to the AC side output end of the power conversion circuit 200, and is used to sample the AC side voltage of the power conversion circuit 200; the second microcontroller 410 is used to process the AC side voltage output by the second sampling circuit 420, and output the AC side voltage in the form of a digital signal, so that the programmable logic device 311 can process the AC side voltage in the form of a digital signal to obtain the switching frequency of the switch tube.

[0116] The third filter circuit is used to filter the second duty cycle voltage to obtain the target feedback voltage. In a possible implementation, the third filter circuit has the same topology as the first filter circuit, and is a sampling RC filter circuit, such as Figure 8 As shown, the third filtering circuit includes a resistor R4 and a capacitor C2. In this embodiment, the third filtering circuit converts the second duty cycle voltage outputted by the digital output terminal of the programmable logic device 311 into a target feedback voltage in the form of an analog signal.

[0117] The second feedback circuit in the switch tube driving voltage control circuit provided in the above embodiment is implemented using a programmable logic device 311 for calculating the switching frequency and a third filtering circuit. There is no need to set up a sampling circuit and a processing device separately for the second feedback circuit, which simplifies the circuit structure and improves the processing efficiency of the second feedback circuit.

[0118] In an exemplary embodiment, the second feedback circuit 310 includes a third microcontroller, wherein the third microcontroller is used to obtain the switching frequency of the switch tube. Exemplarily, the third microcontroller is used to connect to the output end of the programmable logic device. In this embodiment, the programmable logic device is used to determine the switching frequency of the switch tube based on the AC side voltage. The output end of the programmable logic device is connected to each switch tube in the power conversion circuit and to the input end of the third microcontroller.

[0119] Optionally, the output end of the third microcontroller includes a digital-analog output end, and the digital-analog output end of the third microcontroller is connected to the feedback input end of the power supply circuit 130. The third microcontroller is used to process according to the second mapping relationship based on the target switching frequency and output the target feedback voltage through the digital-analog output end.

[0120] In a possible implementation of this embodiment, the third microcontroller and Figure 8 The second microcontroller in is the same controller.

[0121] In an exemplary embodiment, a method for controlling a switch tube driving voltage is provided; in this embodiment, the method is used for Figures 2 to 3The first microcontroller 121 in the embodiment is used as an example for explanation. It can be understood that the method provided in this embodiment can also be used in other controllers or computer devices connected to the power supply circuit 130 and the first sampling circuit 110. Please refer to Fig. 9 , the method includes step 902 to step 902, wherein:

[0122] Step 902: Obtain a target sampling voltage corresponding to the AC side voltage of the power conversion circuit.

[0123] Exemplarily, the real-time sampling voltage corresponding to the AC side voltage of the power conversion circuit is obtained through the first sampling circuit 110 connected to the first microcontroller 121 .

[0124] Step 904 , mapping the target sampling voltage according to the first mapping relationship to obtain a target feedback voltage.

[0125] The first mapping relationship includes that the amplitude of the feedback voltage corresponding to the first sampling voltage is not greater than the amplitude of the feedback voltage corresponding to the second sampling voltage, and the amplitude of the first sampling voltage is greater than the amplitude of the second sampling voltage.

[0126] The target feedback voltage is used to determine the target driving voltage for driving the switch tube to conduct based on the target feedback voltage. The relationship between the amplitude of the target driving voltage and the amplitude of the target feedback voltage is negatively correlated, and the switching frequency of the switch tube changes with the amplitude of the AC side voltage.

[0127] In an exemplary embodiment, based on Fig. 9 The embodiment shown in the figure relates to a process of mapping a target sampling voltage according to a first mapping relationship to obtain a target feedback voltage: processing the target sampling voltage according to the first mapping relationship to obtain a target feedback voltage amplitude; obtaining a first duty cycle voltage based on the target feedback voltage amplitude; and filtering the first duty cycle voltage to obtain a target feedback voltage.

[0128] In an exemplary embodiment, a method for controlling a switch tube driving voltage is provided; in this embodiment, the method is used for Figure 8 The second feedback circuit 310 shown is used as an example for explanation. It is understandable that the method provided in this embodiment can also be used in other circuits or computer devices that can calculate or obtain the switching frequency of the switch tube and are connected to the power supply circuit. Fig.10 , the method comprises steps 1002 and 1004, wherein:

[0129] Step 1002, obtaining a target switching frequency of a switch tube of a power conversion circuit.

[0130] Exemplarily, the programmable logic device 311 performs calculations based on the AC side voltage to obtain a target switching frequency of the switch tube.

[0131] Step 1004: Process the target switching frequency according to the second mapping relationship to obtain a target feedback voltage, wherein the second mapping relationship includes that the amplitude of the feedback voltage corresponding to the first switching frequency is not less than the amplitude of the feedback voltage corresponding to the second switching frequency, and the first switching frequency is greater than the second switching frequency.

[0132] Among them, the target feedback voltage is used to determine the target driving voltage for driving the switch tube to conduct based on the target feedback voltage. The relationship between the amplitude of the target driving voltage and the amplitude of the target feedback voltage is negatively correlated, and the switching frequency of the switch tube changes with the amplitude of the AC side voltage of the power conversion circuit.

[0133] Optionally, the target switching frequency is processed by the programmable logic device 311 according to the second mapping relationship to obtain a target feedback voltage amplitude, and a second duty cycle voltage is obtained based on the target feedback voltage amplitude; the second duty cycle voltage is filtered by a third filtering circuit to obtain the target feedback voltage.

[0134] In an exemplary embodiment, a computer device is provided, which may be the first microcontroller 121 in the power converter, or the programmable logic device 311 in the power converter, or the third microcontroller; its internal structure diagram may be as shown in FIG. Fig.11 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data that needs to be stored and called when executing the pole welding control method. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, at least some steps in a switch tube drive voltage control method are implemented.

[0135] Those skilled in the art will understand that Figure 8The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0136] In one embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

[0137] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0138] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0139] In an exemplary embodiment, a power converter is provided, which includes the switch tube drive voltage control circuit 100 and the power conversion circuit 200 provided in the above embodiment, wherein the switch tube drive voltage control circuit 100 is connected to the driving end of each switch tube in the power conversion circuit 200 .

[0140] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0141] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0142] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A switch tube driving voltage control circuit, characterized in that: The switch tube drive voltage control circuit is used to connect to each switch tube in the power conversion circuit, and the switch tube drive voltage control circuit includes: a first sampling circuit, a first feedback circuit, a power supply circuit and a drive circuit, wherein: The first sampling circuit is used to sample the AC side voltage of the power conversion circuit to obtain a target sampling voltage; The first feedback circuit is used to process the target sampling voltage according to a first mapping relationship to obtain a target feedback voltage, wherein the first mapping relationship includes that the amplitude of the feedback voltage corresponding to the first sampling voltage is not greater than the amplitude of the feedback voltage corresponding to the second sampling voltage, and the amplitude of the first sampling voltage is greater than the amplitude of the second sampling voltage; The power supply circuit is used to output a target power supply voltage based on the target feedback voltage, and the relationship between the amplitude of the target power supply voltage and the amplitude of the target feedback voltage is negatively correlated; The driving circuit is used to output a target driving voltage based on the target power supply voltage to drive the switch tube to be turned on, wherein the switching frequency of the switch tube varies with the amplitude of the AC side voltage.

2. The switch tube driving voltage control circuit according to claim 1, characterized in that: The first feedback circuit comprises: A first microcontroller, wherein an input end of the first microcontroller is connected to an output end of the sampling circuit, and an output end of the first microcontroller is connected to a feedback input end of the power supply circuit.

3. The switch tube driving voltage control circuit according to claim 2, characterized in that: The output terminal of the first microcontroller includes a digital-to-analog output terminal of the first microcontroller; The first microcontroller is used to process the target sampling voltage according to the first mapping relationship and output the target feedback voltage through the digital-to-analog output terminal.

4. The switch tube driving voltage control circuit according to claim 2, characterized in that: The output end of the first microcontroller includes a duty cycle output end; the feedback circuit further includes a first filter circuit, the input end of the first filter circuit is connected to the duty cycle output end, and the output end of the first filter circuit is connected to the feedback input end of the power supply circuit; The first microcontroller is used for processing the target sampled voltage according to the first mapping relationship, and outputting a first duty cycle voltage through the duty cycle output terminal; The first filtering circuit is used to filter the first duty cycle voltage to obtain the target feedback voltage.

5. The switch tube driving voltage control circuit according to claim 1, characterized in that: The first mapping relationship includes a linear relationship between the amplitude of the feedback voltage and the amplitude of the sampling voltage.

6. The switch tube driving voltage control circuit according to claim 1, characterized in that: The first mapping relationship includes a nonlinear relationship between the amplitude of the feedback voltage and the amplitude of the sampling voltage.

7. The switch tube driving voltage control circuit according to claim 1, characterized in that: The first feedback circuit includes a rectifier circuit and a second filter circuit, wherein: The rectifier circuit is used to perform rectification and phase shift processing on the target sampling voltage to obtain a rectified voltage; The second filtering circuit is used to filter and amplify the rectified voltage to obtain the target feedback voltage.

8. The switch tube driving voltage control circuit according to claim 1, characterized in that: The power supply circuit includes an auxiliary source chip, a first resistor, a second resistor and a third resistor; wherein, The output end of the auxiliary source chip is connected to the first end of the first resistor, and the feedback input end of the auxiliary source chip is connected to the second end of the first resistor, the first end of the second resistor, and the first end of the third resistor; The second end of the second resistor is grounded; The second end of the third resistor is connected to the output end of the feedback circuit.

9. A switch tube driving voltage control circuit, characterized in that: The switch tube drive voltage control circuit is used to connect to each switch tube in the power conversion circuit, and the switch tube drive voltage control circuit includes: a second feedback circuit, a power supply circuit and a drive circuit, wherein: The second feedback circuit is used to obtain a target switching frequency of the switch tube, and process the target switching frequency according to a second mapping relationship to obtain a target feedback voltage, wherein the second mapping relationship includes that an amplitude of the feedback voltage corresponding to the first switching frequency is not less than an amplitude of the feedback voltage corresponding to the second switching frequency, and the first switching frequency is greater than the second switching frequency; The power supply circuit is used to output a target power supply voltage based on the target feedback voltage, and the relationship between the amplitude of the target power supply voltage and the amplitude of the target feedback voltage is negatively correlated; The driving circuit is used to output a target driving voltage based on the target power supply voltage to drive the switch tube to be turned on, wherein the switching frequency of the switch tube varies with the amplitude of the AC side voltage of the power conversion circuit.

10. The switch tube driving voltage control circuit according to claim 9, characterized in that: The second feedback circuit includes a programmable logic device and a third filter circuit, the output end of the third filter circuit is connected to the digital output end of the programmable logic device, and the output end of the third filter circuit is connected to the feedback input end of the power supply circuit; wherein, The programmable logic device is used to obtain the target switching frequency, and process according to the second mapping relationship based on the target switching frequency, and output a second duty cycle voltage through the digital output terminal; The third filtering circuit is used to filter the second duty cycle voltage to obtain the target feedback voltage.

11. A method for controlling a switch tube driving voltage, characterized in that: The method comprises: Obtaining a target sampling voltage corresponding to an AC side voltage of a power conversion circuit; Mapping the target sampling voltage according to a first mapping relationship to obtain a target feedback voltage, wherein the first mapping relationship includes that the amplitude of the feedback voltage corresponding to the first sampling voltage is not greater than the amplitude of the feedback voltage corresponding to the second sampling voltage, and the amplitude of the first sampling voltage is greater than the amplitude of the second sampling voltage; Among them, the target feedback voltage is used to determine the target driving voltage for driving the switching tube to conduct based on the target feedback voltage, the relationship between the amplitude of the target driving voltage and the amplitude of the target feedback voltage is negatively correlated, and the switching frequency of the switching tube changes with the amplitude of the AC side voltage.

12. A method for controlling a switch tube driving voltage, characterized in that: The method comprises: Obtaining a target switching frequency of a power conversion circuit switch tube; Processing the target switching frequency according to a second mapping relationship to obtain a target feedback voltage, wherein the second mapping relationship includes that an amplitude of the feedback voltage corresponding to the first switching frequency is not less than an amplitude of the feedback voltage corresponding to the second switching frequency, and the first switching frequency is greater than the second switching frequency; Among them, the target feedback voltage is used to determine the target driving voltage for driving the switching tube to conduct based on the target feedback voltage, the relationship between the amplitude of the target driving voltage and the amplitude of the target feedback voltage is negatively correlated, and the switching frequency of the switching tube changes with the amplitude of the AC side voltage of the power conversion circuit.

13. A power converter, characterized in that: The power converter comprises a switch tube driving voltage control circuit and a power conversion circuit as described in any one of claims 1 to 10; Wherein, the switch tube driving voltage control circuit is connected to the driving end of each switch tube in the power conversion circuit.

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