Switch transistor driving voltage control circuit and method, and power converter

Abstract

The present application relates to a switch transistor driving voltage control circuit and method, and a power converter. The switch transistor driving voltage control circuit in one aspect is used for connecting to each switch transistor in a power converter, and comprises a sampling circuit, a first feedback circuit, a power source circuit and a driving circuit, wherein a first sampling circuit is used for performing sampling processing on an alternating-current-side voltage of a power conversion circuit, so as to obtain a target sampled voltage; the first feedback circuit is used for performing processing according to a first mapping relationship on the basis of the target sampled voltage, so as to obtain a target feedback voltage; the power source circuit is used for outputting a target power source voltage on the basis of the target feedback voltage; and the driving circuit is used for outputting a target driving voltage on the basis of the target power source voltage, so as to drive the switch transistor to be turned on. By using the above switch transistor driving voltage control circuit, the conversion efficiency of a power converter can be improved.

Description

Switch drive voltage control circuit, method and power converter Related applications

[0001] This application claims priority to Chinese patent application filed on October 23, 2024, with application number 202411487993X, entitled "Switching transistor drive voltage control circuit, method and power converter", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of power conversion technology, and in particular to a switching transistor drive voltage control circuit, method, and power converter. Background Technology

[0003] A power converter is a power conversion device used to transform electrical energy from one form to another, enabling energy transmission and control under different power requirements. The working principle of a power converter involves using a control circuit to continuously "turn on" and "turn off" a switching transistor. When the switching transistor pulses the input voltage, it achieves power conversion such as DC-AC voltage conversion or DC-DC voltage conversion.

[0004] In related technologies, the magnitude of the driving voltage of the gate of the switching transistor is fixed, resulting in low conversion efficiency of the power converter. Summary of the Invention

[0005] Therefore, it is necessary to provide a switching transistor drive voltage control circuit, method, and power converter that can improve the conversion efficiency of the power converter, addressing the aforementioned technical problems.

[0006] In a first aspect, this application provides a switching transistor drive voltage control circuit for connection to each switching transistor in a power converter. The switching transistor drive voltage control circuit includes: a first sampling circuit, a first feedback circuit, a power supply circuit, and a drive circuit, wherein...

[0007] The first sampling circuit is used to sample the AC side voltage of the power conversion circuit to obtain the target sampling voltage;

[0008] The first feedback circuit is used to process the target sampled voltage according to a 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 sampled voltage is not greater than the amplitude of the feedback voltage corresponding to the second sampled voltage, and the amplitude of the first sampled voltage is greater than the amplitude of the second sampled voltage.

[0009] The power supply circuit is used to output a target power supply voltage based on the target feedback voltage. The amplitude of the target power supply voltage and the amplitude of the target feedback voltage are negatively correlated.

[0010] The driving circuit is used to output a target driving voltage based on the target power supply voltage to drive the switching transistor to turn on, wherein the switching frequency of the switching transistor varies with the magnitude of the AC side voltage.

[0011] In one embodiment, the first feedback circuit includes:

[0012] The first microcontroller has its input terminal connected to the output terminal of the sampling circuit, and its output terminal connected to the feedback input terminal of the power supply circuit.

[0013] In one embodiment, the output of the first microcontroller includes the analog-to-digital output of the first microcontroller;

[0014] The first microcontroller is used to process the target sampled voltage according to the first mapping relationship and output the target feedback voltage through the digital-to-analog output terminal.

[0015] In one embodiment, the output terminal of the first microcontroller includes a duty cycle output terminal; the feedback circuit further includes a first filter circuit, the input terminal of the first filter circuit is connected to the duty cycle output terminal, and the output terminal of the first filter circuit is connected to the feedback input terminal of the power supply circuit.

[0016] The first microcontroller is used to process the target sampled voltage according to the first mapping relationship, and outputs the first duty cycle voltage through the duty cycle output terminal;

[0017] The first filter circuit is used to filter the first duty cycle voltage to obtain the target feedback voltage.

[0018] 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.

[0019] In one embodiment, the first mapping relationship includes a non-linear relationship between the amplitude of the feedback voltage and the amplitude of the sampling voltage.

[0020] In one embodiment, the first feedback circuit includes a rectifier circuit and a second filter circuit, wherein,

[0021] The rectifier circuit is used to rectify and phase-shift the target sampled voltage to obtain the rectified voltage;

[0022] The second filter circuit is used to filter and amplify the rectified voltage to obtain the target feedback voltage.

[0023] In one embodiment, the power supply circuit includes an auxiliary power chip, a first resistor, a second resistor, and a third resistor; wherein,

[0024] The output terminal of the auxiliary power chip is connected to the first terminal of the first resistor, and the feedback input terminal of the auxiliary power chip is connected to the second terminal of the first resistor, the first terminal of the second resistor, and the first terminal of the third resistor.

[0025] The second terminal of the second resistor is grounded;

[0026] The second terminal of the third resistor is connected to the output terminal of the feedback circuit.

[0027] Secondly, this application provides a switching transistor drive voltage control circuit for connection to each switching transistor in a power conversion circuit. The switching transistor drive voltage control circuit includes: a second feedback circuit, a power supply circuit, and a drive circuit, wherein...

[0028] The second feedback circuit is used to obtain the target switching frequency of the switching transistor and process it according to the second mapping relationship based on the target switching frequency 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.

[0029] The power supply circuit is used to output a target power supply voltage based on the target feedback voltage. The amplitude of the target power supply voltage and the amplitude of the target feedback voltage are negatively correlated.

[0030] The driving circuit is used to output a target driving voltage based on the target power supply voltage to drive the switching transistor to conduct. The switching frequency of the switching transistor varies with the magnitude of the AC side voltage of the power conversion circuit.

[0031] In one embodiment, the second feedback circuit includes a programmable logic device and a third filter circuit. The output of the third filter circuit is connected to the digital output of the programmable logic device, and the output of the third filter circuit is connected to the feedback input of the power supply circuit.

[0032] The programmable logic device is used to obtain the target switching frequency and process it according to the second mapping relationship based on the target switching frequency, and output the second duty cycle voltage through the digital output terminal;

[0033] The third filter circuit is used to filter the second duty cycle voltage to obtain the target feedback voltage.

[0034] Thirdly, this application also provides a method for controlling the driving voltage of a switching transistor, including:

[0035] Obtain the target sampling voltage corresponding to the AC side voltage of the power conversion circuit;

[0036] The target sampling voltage is mapped 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.

[0037] The target feedback voltage is used to determine the target driving voltage for driving the switch to turn on based on the target feedback voltage. The amplitude of the target driving voltage is negatively correlated with the amplitude of the target feedback voltage. The switching frequency of the switch changes with the amplitude of the AC side voltage.

[0038] Fourthly, this application also provides a method for controlling the drive voltage of a switching transistor, including:

[0039] Obtain the target switching frequency of the switching transistor in the power conversion circuit;

[0040] The target switching frequency is processed 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.

[0041] The target feedback voltage is used to determine the target driving voltage for driving the switch to turn on based on the target feedback voltage. The amplitude of the target driving voltage is negatively correlated with the amplitude of the target feedback voltage. The switching frequency of the switch changes with the amplitude of the AC side voltage of the power conversion circuit.

[0042] Fifthly, this application also provides a power converter, which includes a switching transistor drive voltage control circuit and a power conversion circuit as described in the first or second aspect.

[0043] The switching transistor drive voltage control circuit is connected to the drive terminals of each switching transistor in the power conversion circuit.

[0044] The aforementioned switch-driven voltage control circuit, method, and power converter, in one aspect, include a switch-driven voltage control circuit for connection to each switch in the power conversion circuit, comprising: a first sampling circuit, a first feedback circuit, a power supply circuit, and a drive circuit. The first sampling circuit samples the AC side voltage of the power conversion circuit to obtain a target sampling voltage. The first feedback circuit processes the target sampling voltage according to a first mapping relationship to obtain a 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 that the amplitude of the first sampling voltage is greater than the amplitude of the second sampling voltage. The power supply circuit outputs a target power supply voltage based on the target feedback voltage, wherein the amplitude of the target power supply voltage and the amplitude of the target feedback voltage are negatively correlated. The drive circuit... This circuit is used to output a target drive voltage based on a target power supply voltage to drive the switching transistor to conduct. The switching frequency of the switching transistor varies with the amplitude of the AC side voltage. By sampling the AC side voltage of the power conversion circuit and processing it through a first feedback circuit, a feedback voltage that is negatively correlated with the first sampled voltage is obtained. Then, a power supply circuit with feedback voltage control performs 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 is established between the amplitudes of the AC side voltages of the drive circuit and the power conversion circuit through the first sampling circuit, the first feedback circuit, and the power supply circuit. This allows the target drive voltage output by the drive circuit to dynamically adjust in line with the amplitude of the AC side voltage, dynamically reducing drive losses and conduction losses, and improving the conversion efficiency of the power converter. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 is a structural block diagram of a switch drive voltage control circuit in one embodiment;

[0047] Figure 2 is a block diagram of the switch drive voltage control circuit in another embodiment;

[0048] Figure 3 is a block diagram of the switch drive voltage control circuit in another embodiment;

[0049] Figure 4 is an exemplary schematic diagram of the voltage waveforms of the AC side voltage and the drive voltage in one embodiment;

[0050] Figure 5 is an exemplary schematic diagram of the voltage waveforms of the AC side voltage, feedback voltage, and drive voltage in one embodiment;

[0051] Figure 6 is a block diagram of the switch drive voltage control circuit in another embodiment;

[0052] Figure 7 is a block diagram of the switch drive voltage control circuit in another embodiment;

[0053] Figure 8 is a block diagram of the switch drive voltage control circuit in another embodiment;

[0054] Figure 9 is a flowchart illustrating a switch drive voltage control method in one embodiment;

[0055] Figure 10 is a flowchart illustrating the switch drive voltage control method in another embodiment;

[0056] Figure 11 is an internal structure diagram of a computer device in one embodiment. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0059] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. 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.

[0060] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0061] It is understood that the term "based on" as used in this application is used to describe one or more factors that influence the determination, but does not exclude other factors that may influence 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 influences the determination of A, but does not exclude the fact that the determination of A is also based on C.

[0062] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0063] The switching drive voltage control circuit provided in this application embodiment is used in a power converter where the switching transistors are actively driven. For example, the power converter is a DC-AC converter employing a Dual Active Bridge (DAB) topology. The DAB DC-AC converter is a power conversion topology with dual active bridges, including eight power transistors, where four transistors form a DC-side full-bridge circuit and the other four transistors form an AC-side half-bridge circuit.

[0064] The switching transistor can also be called a power transistor. In this application embodiment, the switching transistor is a voltage-driven switching transistor, including but not limited to MOS transistor (Metal-Oxide-Semiconductor Field-Effect Transistor) and IGBT (Insulated Gate Bipolar Transistor).

[0065] First, we will introduce the principle of the switching transistor drive voltage control circuit provided in this embodiment to facilitate a clear understanding of this solution.

[0066] Taking a MOSFET as an example, the MOSFET can be turned on when the gate drive voltage reaches its turn-on threshold. Within the MOSFET's tolerance range, a higher gate drive voltage results in a lower on-resistance and correspondingly lower conduction losses. However, higher drive voltages also require more energy from the MOSFET's drive circuit, leading to greater drive losses. Extensive experimental research by the applicant has revealed that the conduction losses of MOSFETs become more pronounced with higher output power (i.e., higher output current) in the power converter, and the drive losses become more significant with higher switching frequencies.

[0067] In power converters with actively driven switching transistors, the control logic dictates that the larger the AC voltage amplitude, the greater the instantaneous power of the power converter, and the lower the switching frequency of the switching transistors. Specifically, when the AC voltage is near its peak, the power converter's output power is higher, and the switching frequency of the MOSFETs is lower; when the AC voltage is near its zero-crossing point, the power converter's output power is lower, and the switching frequency of the MOSFETs is higher. Taking a micro-inverter based on a DAB topology in grid-connected operation as an example, near the peak of the grid voltage, the switching frequency of each MOSFET in the micro-inverter is lower, while the power converter's output power is higher; near the zero-crossing point of the grid voltage, the switching frequency of each MOSFET in the inverter is higher, and the power converter's output power is lower. That is, within one AC cycle, the switching frequency of the MOSFETs is negatively correlated with the absolute value of the AC voltage, while the operating current of the MOSFETs is positively correlated with the absolute value of the AC voltage.

[0068] Based on this, this application provides a switching transistor drive voltage control circuit through the following embodiments. When the AC side voltage amplitude is high, the drive voltage is increased. At this time, the switching frequency of the MOSFET is low, and the drive loss is not obvious. However, the conduction current is high, and the conduction loss is significant. Combined with the fact that the higher the drive voltage, the lower the conduction loss, and the greater the drive loss, the overall loss of the MOSFET is low, and the power converter efficiency is high. Conversely, when the AC side voltage amplitude is low, the drive voltage is decreased. At this time, the switching frequency of the MOSFET is high, and the drive loss is significant. However, the conduction current is low, and the conduction loss is not obvious. Combined with the characteristic that the lower the drive voltage, the greater the conduction loss, and the lower the drive loss, the overall loss of the MOSFET is low, and the power converter efficiency is high. In this way, the conduction loss and drive loss of the MOSFET are dynamically reduced, the overall loss of the power conversion circuit is reduced, and the efficiency of the power converter is ultimately improved.

[0069] In an exemplary embodiment, the provided switch drive voltage control circuit 100 is used to connect to each switch in the power conversion circuit. Referring to FIG1, the switch drive voltage control circuit 100 includes a first sampling circuit 110, a first feedback circuit 120, a power supply circuit 130, and a drive circuit 140.

[0070] The first sampling circuit 110 is used to sample the AC side voltage of the power conversion circuit to obtain the target sampling voltage.

[0071] For example, the AC side of the power converter can be connected to the power grid, and the AC side voltage is the grid voltage; for example, the AC side of the power converter can also be connected to an AC load, and the AC side voltage is the load voltage.

[0072] For example, the first sampling circuit 110 may be a current transformer and a resistor, 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. Here, N is the transformation ratio of the current transformer. Alternatively, the first sampling circuit 110 may include a voltage sampling chip.

[0073] The first feedback circuit 120 processes the target sampled voltage according to a first mapping relationship to obtain a target feedback voltage. The first mapping relationship includes that the amplitude of the feedback voltage corresponding to the first sampled voltage is not greater than the amplitude of the feedback voltage corresponding to the second sampled voltage, and that the amplitude of the first sampled voltage is greater than the amplitude of the second sampled voltage. The power supply circuit 130 outputs a target power supply voltage based on the target feedback voltage; the amplitude of the target power supply voltage and the amplitude of the target feedback voltage are negatively correlated. The drive circuit 140 outputs a target drive voltage based on the target power supply voltage to drive the switching transistors to conduct. The switching frequency of the switching transistors varies with the amplitude of the AC side voltage; specifically, the larger the amplitude of the AC side voltage, the greater 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 drive voltages to the switching transistors in the power conversion circuit 200. For example, the power conversion circuit 200 is a DAB topology circuit.

[0074] For example, the drive circuit 140 can be connected to a programmable logic device in a power converter to control the switching frequency of each switch.

[0075] The input terminal of the first feedback circuit 120 is connected to the first sampling circuit 110, and the output terminal of the first feedback circuit 120 is connected to the feedback input terminal of the power supply circuit 130, so that the power supply circuit 130 can adjust the output voltage of the power supply circuit 130 based on the output of the first feedback circuit 120.

[0076] The target feedback voltage is obtained by processing the target sampling voltage according to the first mapping relationship. The trend of the target feedback voltage and the target sampling voltage is opposite, that is, the larger the amplitude of the sampling voltage, the smaller the amplitude of the feedback voltage. The amplitude of the target power supply voltage and the amplitude of the target feedback voltage are negatively correlated, that is, the smaller the target feedback voltage, the larger the target power supply voltage. Thus, after passing through the first feedback circuit 120 and the power supply circuit 130, the amplitude of the target power supply voltage input to the drive circuit 140 is positively correlated with the amplitude of the target sampling voltage. This makes the amplitude of the target drive voltage output by the drive circuit 140 to the switching transistor positively correlated with the amplitude of the target sampling voltage. This achieves a larger drive voltage for the switching transistor when the amplitude of the AC side voltage is large, and a lower drive voltage for the switching transistor when the amplitude of the AC side voltage is small, dynamically reducing the conduction loss and drive loss of the MOSFET.

[0077] Here, the first sampling voltage and the second sampling voltage refer to any two voltages with different amplitudes that the first sampling circuit 110 can output. The first sampling voltage refers to the sampling voltage with a larger amplitude, and the second sampling voltage refers to the sampling voltage with a smaller amplitude. In this embodiment, the first sampling voltage and the second sampling voltage are used to illustrate the mapping relationship between the sampling voltage and the feedback voltage included in the first mapping relationship.

[0078] In one 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 the fact that the amplitude of the feedback voltage corresponding to the first sampling voltage is less 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. That is, the first mapping relationship means that the larger the sampling voltage, the smaller the amplitude of the feedback voltage.

[0079] For example, the first mapping relationship is Vo = AB * |Vac|, where Vo represents the feedback voltage, Vac represents the sampling voltage, and A and B are pre-set mapping parameters. For example, A = 2.35, B = 0.00163. In this example, the mapping parameters A and B were obtained by the applicant based on the hardware parameters of the power supply circuit and the electrical characteristics of the switching transistor used in the experiment, as well as the actual experimental results. They are not intended to limit the mapping parameters. It is understood that those skilled in the art can determine the mapping parameters based on specific implementation conditions, including but not limited to the hardware parameters of the power supply circuit and / or the electrical characteristics of the switching transistor.

[0080] In one possible implementation, the first mapping relationship includes a non-linear 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 interval corresponding to a different feedback voltage, and the sampling voltage within the same amplitude interval corresponds to the same feedback voltage; overall, the sampling voltage and the feedback voltage are negatively correlated. For example, the first mapping relationship includes a piecewise function. Another example is a list mapping relationship.

[0081] In one possible implementation, the first feedback circuit 120 is implemented using pure hardware circuitry. In another possible implementation, the first feedback circuit 120 includes a first microcontroller 121, i.e., it is implemented through a combination of hardware and software. Here, microcontroller stands for Microcontroller Unit, abbreviated as MCU.

[0082] The power supply circuit 130 adjusts the output power supply voltage according to the input feedback voltage. The larger the amplitude of the input feedback voltage, the smaller the amplitude of the output power supply voltage; conversely, the smaller the amplitude of the input feedback voltage, the smaller the amplitude of the output power supply voltage. This power supply voltage refers to the power supply voltage of the input drive circuit 140.

[0083] In one possible implementation, referring to Figures 2 and 3, the power supply circuit 130 includes an auxiliary power chip 131 with voltage feedback characteristics and corresponding peripheral circuitry. As shown in Figures 2 and 3, Vout is the power supply voltage output by the power supply circuit 130, Vo refers to the feedback voltage, and FB refers to the feedback pin of the auxiliary power chip 131. Referring to Figures 2 and 3, the peripheral circuitry includes a first resistor R1, a second resistor R2, and a third resistor RFB. The output terminal of the auxiliary power chip 131 is connected to the first terminal of the first resistor R1, the feedback input terminal of the auxiliary power chip 131 is connected to the second terminals of the first resistor R1, the first terminals of the second resistor R2, and the first terminals of the third resistor RFB. The second terminal of the second resistor R2 is grounded, and the second terminal of the third resistor R3 is connected to the output terminal of the first feedback circuit 120.

[0084] The power supply voltage Vout output by the power supply circuit 130 is controlled by the voltage of its feedback pin and can provide the gate drive voltage for the MOSFET through the drive circuit 140.

[0085] For example, auxiliary power chip 131 is a BUCK power chip.

[0086] The switching transistor drive voltage control circuit 100 provided in the above embodiment is used to connect to each switching transistor 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. The first sampling circuit 110 is used to sample the AC side voltage of the power conversion circuit to obtain a target sampling voltage; the first feedback circuit 120 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 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 feedback voltage. The source voltage is used to output the target drive voltage to drive the switching transistor to conduct. The switching frequency of the switching transistor varies with the amplitude of the AC side voltage. Thus, 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. Then, the power supply circuit 130 with 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 is established between the drive voltage and the amplitude of the AC side voltage of the power conversion circuit through the first sampling circuit 110, the first feedback circuit 120, and the power supply circuit 130. This allows the target drive voltage output by the drive circuit 140 to drive the switching transistor to dynamically adjust in a positive correlation with the amplitude of the AC side voltage, dynamically reducing drive losses and conduction losses, and improving the conversion efficiency of the power converter.

[0087] For example, when the switching transistor drive voltage control circuit 100 provided in the above embodiment is applied to the grid-connected operation of a micro inverter based on a DAB topology, please refer to Figure 4. At the peak point A of the grid voltage, the switching frequency of the switching transistor is low, the output current is large, and the conduction loss is the main factor. The drive voltage is increased to reduce the conduction loss. At the zero-crossing point B of the grid voltage, the switching frequency of the MOSFET is high, the output current of the micro inverter is small, and the drive loss is the main factor. The drive voltage is reduced to reduce the drive loss.

[0088] Please refer to Figure 5, which is an exemplary schematic diagram showing the changing trends of AC side voltage, feedback voltage, and drive voltage. When the first mapping relationship is nonlinear, the waveforms of the feedback voltage and drive voltage can be stepped, and the changing trend of the feedback voltage is opposite to the changing trend of the amplitude of the AC side voltage.

[0089] In an exemplary embodiment, referring to Figures 2 and 3, based on the embodiment shown in Figure 1, the first feedback circuit 120 in the provided switch drive voltage control circuit 100 includes a first microcontroller 121. The input terminal of the first microcontroller 121 is connected to the output terminal of the first sampling circuit 110, and the output terminal of the first microcontroller 121 is connected to the feedback input terminal of the power supply circuit 130.

[0090] In one possible implementation, referring to Figure 2, the output of the first microcontroller 121 includes a digital-to-analog (DA) output, i.e., a DA pin. In this embodiment, the first microcontroller 121 is used to process the target sampled voltage according to a first mapping relationship and output a target feedback voltage through the DA output. The target feedback voltage is an analog signal.

[0091] In this embodiment, the target feedback voltage in analog signal form is directly output using the DA pin on the first microcontroller 121, without the need for additional filtering circuits, resulting in low hardware cost and simple circuit topology.

[0092] In one possible implementation, referring to Figure 3, the output terminal of the first microcontroller 121 includes a duty cycle output terminal, and the first feedback circuit 120 further includes a first filter circuit. The input terminal of the first filter circuit is connected to the duty cycle output terminal, and the output terminal of the first filter circuit is connected to the input terminal of the first feedback circuit 120. The first microcontroller 121 processes the target sampled voltage according to a first mapping relationship and outputs a first duty cycle voltage through the duty cycle output terminal; the first filter circuit filters the first duty cycle voltage to obtain the target feedback voltage.

[0093] For example, please refer to Figure 3. The first filter circuit includes an RC (resistor-capacitor) filter circuit. As shown in Figure 3, the first filter circuit includes a resistor R3 and a capacitor C1.

[0094] For example, the duty cycle output terminal of the first microcontroller 121 can be a general purpose input output (GPIO) pin of the first microcontroller 121; for another example, the duty cycle output terminal of the first microcontroller 121 can be a PWM (Pulse Width Modulator) output pin of the first microcontroller 121, as shown in Figure 3.

[0095] The first duty cycle voltage output from the duty cycle output terminal is in the form of a PWM wave, i.e., a digital signal. It is converted into the target feedback voltage in the form of an analog signal by the first filter circuit.

[0096] In this embodiment, the first duty cycle voltage is first output in digital form by the duty cycle output terminal of the first microcontroller 121, and then filtered into the target feedback voltage in analog form by the first filter circuit. This can reduce the resource occupation of the first microcontroller 121 and avoid insufficient DA pin resources on the first microcontroller 121. Furthermore, the switching transistor drive voltage control circuit 100 provided in this embodiment can be implemented on the first microcontroller 121 which does not have DA pins, thus improving the flexibility of the solution application.

[0097] The switching transistor drive voltage control circuit 100 provided in the above embodiment implements a first feedback circuit 120 based on a first microcontroller 121. The first microcontroller 121 can read the real-time state of the AC side voltage of the power converter through the first sampling circuit 110, connect to the feedback input terminal of the power supply circuit 130, and inject feedback voltage into the power supply circuit 130 to adjust the power supply voltage output by the power supply circuit 130. In this embodiment, the mapping from the sampling voltage to the feedback voltage is realized by the first microcontroller 121 in combination with software, which has high accuracy. The specific parameters in the first mapping relationship can be flexibly adjusted according to the hardware parameters of the switching transistor in the power conversion part of the power converter or the corresponding hardware parameters of the power supply circuit 130. The switching transistor drive voltage control circuit 100 provided in this embodiment has good scalability.

[0098] In one possible implementation of this embodiment, the target drive voltage can be automatically adjusted by the first microcontroller 121 to find the highest efficiency point. For example, based on the waveform of the target power supply voltage currently output by the drive circuit 140, the current efficiency of the power converter is calculated by setting a corresponding closed-loop control algorithm in the first microcontroller 121, so that the drive voltage is within a safe range and the optimal target drive voltage is found automatically. For example, the maximum and minimum amplitudes of the drive voltage waveform in Figure 4 can be adjusted. The straight line in Figure 4 is not an axis representing a voltage of 0.

[0099] In one possible implementation of this embodiment, the first mapping relationship includes a first mapping relationship A and a first mapping relationship B, which correspond to different switching transistors. 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 switching transistors. The first feedback circuit 120 based on the first microcontroller 121 can determine the mapping relationship to be used from the first mapping relationship A and the first mapping relationship B based on the characteristics of the AC side voltage. Alternatively, the first feedback circuit 120 based on the first microcontroller 121 can switch the mapping relationship to be used in response to user input. Furthermore, the first mapping relationship can include a variety of different first mapping relationships. In specific use, the first microcontroller 121 is used to switch the required mapping relationship, thereby improving the scalability of the switching transistor drive voltage circuit.

[0100] In one possible implementation of this embodiment, the first microcontroller 121 is further configured to, during the process of processing the target sampling voltage according to the first mapping relationship to obtain the target feedback voltage, specifically, to obtain an 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 a 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. This prevents the target feedback voltage output by the first feedback circuit 120 from being too small and the target power supply voltage output by the power supply circuit 130 from being too large when the AC side voltage abnormally increases, such as when the mains voltage experiences a high-voltage surge or accumulated surge. Essentially, it sets an upper limit on the driving voltage of the switching transistor, improving the safety of the circuit operation.

[0101] In an exemplary embodiment, referring to FIG6, the first feedback circuit 120 in the provided switch drive voltage control circuit includes a rectifier circuit 122 and a second filter circuit 123. 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.

[0102] For example, rectifier circuit 122 includes a full-bridge rectifier circuit consisting of four diodes and a phase-shifting circuit.

[0103] The full-bridge rectifier circuit rectifies the target sampled voltage to obtain a waveform with the same amplitude change as the AC side voltage. In order to obtain a rectified voltage with a trend opposite to that of the AC side voltage, the phase shift circuit shifts the phase of the rectified voltage by 180° or an integer multiple of 180°.

[0104] For example, the second filter circuit 123 includes an RC filter circuit and an amplifier circuit. The RC filter circuit smooths the rectified voltage to obtain a filtered voltage of the analog signal waveform. The amplifier circuit amplifies the filtered voltage and adjusts its amplitude to obtain the target feedback voltage determined by the first mapping relationship. The amplification factor of the amplifier circuit can be greater than or less than 1. For example, the amplification factor can be determined based on the electrical parameter characteristics of the auxiliary power chip, rectifier circuit 122, and switching transistor used in the power supply circuit 130.

[0105] In one possible implementation, the rectifier circuit 122 includes, in addition to a full-bridge rectifier circuit and a phase-shifting circuit, an isolation circuit. The input of the isolation circuit is connected to the output of the first sampling circuit 110, and the output of the isolation circuit is connected to the full-bridge rectifier circuit. For example, the isolation circuit includes two inverters connected in sequence.

[0106] In this embodiment, the use of an isolation circuit can prevent interference between the first sampling circuit 110 and the rectifier circuit 122, thereby improving the reliability of the switch drive voltage control circuit.

[0107] 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 first stepped down by the step-down circuit to obtain the stepped-down voltage, and then rectified, phase-shifted, and filtered.

[0108] In an exemplary embodiment, referring to FIG7, a switch drive voltage control circuit 300 is provided for connection to each switch in a power converter circuit 200. As shown in FIG7, the switch drive voltage control circuit 300 includes a second feedback circuit 310, a power supply circuit 130, and a drive circuit 140. It is understood that the switch drive voltage control circuit 300 provided in this embodiment adopts a different feedback circuit topology than the switch drive voltage control circuit 300 provided in the previous embodiments, but the same power supply circuit topology and drive circuit topology.

[0109] The second feedback circuit 310 is used to obtain the target switching frequency of the switching transistor and process it according to a 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. The switching frequency of the switching transistor 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 greater the instantaneous power of the power conversion circuit and the smaller the switching frequency. The power supply circuit 130 is used to output a target power supply voltage based on the target feedback voltage. The amplitude of the target power supply voltage and the amplitude of the target feedback voltage are negatively correlated. The drive circuit 140 is used to output a target drive voltage based on the target power supply voltage to drive the switching transistor to conduct.

[0110] In one 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 the fact 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.

[0111] In one possible implementation, the second mapping relationship includes a non-linear 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 numerical values, each frequency interval corresponding to a different feedback voltage, and the switching frequency within the same frequency interval corresponds to the same feedback voltage. In this implementation, there are cases where the switching frequency changes but the amplitude of the feedback voltage remains unchanged; overall, the switching frequency and the feedback voltage have a positively correlated mapping relationship. For example, the second mapping relationship includes a piecewise function; another example is a list mapping relationship.

[0112] In this embodiment, the switching frequency of each switch in the power conversion circuit 200 varies with the amplitude of the AC side voltage of the power conversion circuit. Specifically, when the amplitude of the AC side voltage is large, the switching frequency of the switch is low, such as near the peak value of the AC side voltage, where the switching frequency is lowest. Conversely, when the amplitude of the AC side voltage is small, the switching frequency of the switch is high, such as near the zero-crossing point of the AC side voltage, where the switching frequency is highest. Based on this, this embodiment directly adjusts the amplitude of the drive voltage of the switch according to its switching frequency. That is, the second feedback circuit 310 directly obtains the switching frequency used to control the switch and outputs a feedback voltage according to the switching frequency to adjust the power supply voltage output by the power supply circuit 130, so that the drive voltage is adjusted accordingly. The drive voltage output by circuit 140 varies with the switching frequency of the switching transistor. The switching frequency is first processed by the second feedback circuit 310 to obtain a feedback voltage positively correlated with the switching frequency. Then, the power supply circuit 130 with feedback voltage control function performs a second processing based on the feedback voltage to obtain a power supply voltage negatively correlated with the feedback voltage. By establishing a negative correlation between the drive voltage and the switching frequency of the switching transistor in the power conversion circuit through the second feedback circuit 310 and the power supply circuit 130, the target drive voltage output by the drive circuit 140 for driving the switching transistor can be dynamically adjusted negatively correlated with the switching frequency of the switching transistor, thereby dynamically reducing drive loss and conduction loss and improving the conversion efficiency of the power converter.

[0113] In an exemplary embodiment, based on the embodiment shown in FIG7, please refer to FIG8, the second feedback circuit includes a programmable logic device 311 and a third filter circuit; the output terminal of the third filter circuit is connected to the digital output terminal of the programmable logic device, and the output terminal of the third filter circuit is connected to the feedback input terminal of the power supply circuit 130.

[0114] The programmable logic device 311 is used to acquire the target switching frequency and process it according to a second mapping relationship, outputting a second duty cycle voltage through a 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 switching transistor.

[0115] For example, the programmable logic device 311 is implemented using a CPLD (Complex Programmable Logic Device). As another example, the programmable logic device 311 is implemented using an FPGA (Field Programmable Gate Array).

[0116] In one possible implementation, referring to Figure 8, the input terminal of the programmable logic device 311 is connected to the output terminal of the second microcontroller 410. The input terminal of the second microcontroller 410 is connected to the output terminal of the second sampling circuit 420. The input terminal of the second sampling circuit 420 is connected to the AC side output terminal of the power conversion circuit 200 for sampling 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 switching transistor.

[0117] The third filter circuit is used to filter the second duty cycle voltage to obtain the target feedback voltage. In one possible implementation, the third filter circuit has the same topology as the first filter circuit, using a sampling RC filter circuit, as shown in Figure 8. The third filter circuit includes a resistor R4 and a capacitor C2. In this embodiment, the third filter circuit converts the second duty cycle voltage output from the digital output terminal of the programmable logic device 311 into the target feedback voltage in the form of an analog signal.

[0118] In the switching transistor drive voltage control circuit provided in the above embodiment, the second feedback circuit is implemented using a programmable logic device 311 that calculates the switching frequency and a third filter circuit. There is no need to set up a sampling circuit and processing device separately for the second feedback circuit, which simplifies the circuit structure and improves the processing efficiency of the second feedback circuit.

[0119] In one exemplary embodiment, the second feedback circuit 310 includes a third microcontroller, which is used to acquire the switching frequency of the switching transistors. Exemplarily, the third microcontroller is connected to the output of a programmable logic device (PLD). In this embodiment, the PLD is used to determine the switching frequency of the switching transistors based on the AC side voltage. The output of the PLD is connected to each switching transistor in the power conversion circuit and to the input of the third microcontroller.

[0120] In some embodiments, the output terminal of the third microcontroller includes a digital-to-analog output terminal, which is connected to the feedback input terminal of the power supply circuit 130. The third microcontroller is used to process data according to a second mapping relationship based on the target switching frequency and output a target feedback voltage through the digital-to-analog output terminal.

[0121] In one possible implementation of this embodiment, the third microcontroller is the same controller as the second microcontroller in FIG8.

[0122] In an exemplary embodiment, a method for controlling the drive voltage of a switching transistor is provided. This embodiment uses the method in the first microcontroller 121 in Figures 2 and 3 as an example for illustration. 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 Figure 9, the method includes steps 902 to 902, wherein:

[0123] Step 902: Obtain the target sampling voltage corresponding to the AC side voltage of the power conversion circuit.

[0124] For example, the real-time sampling voltage corresponding to the AC side voltage of the power conversion circuit is obtained by the first sampling circuit 110 connected to the first microcontroller 121.

[0125] Step 904: Map the target sampled voltage according to the first mapping relationship to obtain the target feedback voltage.

[0126] The first mapping relationship includes the fact 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.

[0127] The target feedback voltage is used to determine the target drive voltage for turning on the switch. The amplitude of the target drive voltage is negatively correlated with the amplitude of the target feedback voltage, and the switching frequency of the switch varies with the amplitude of the AC side voltage.

[0128] In an exemplary embodiment, based on the embodiment shown in FIG9, this embodiment relates to the process of mapping the target sampled voltage according to the first mapping relationship to obtain the target feedback voltage: the target sampled voltage is processed according to the first mapping relationship to obtain the target feedback voltage amplitude; the first duty cycle voltage is obtained based on the target feedback voltage amplitude; the first duty cycle voltage is filtered to obtain the target feedback voltage.

[0129] In an exemplary embodiment, a method for controlling the drive voltage of a switching transistor is provided. This embodiment uses the method in the second feedback circuit 310 shown in FIG8 as an example for illustration. It is understood 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 switching transistor and are connected to a power supply circuit. Please refer to FIG10, the method includes steps 1002 and 1004, wherein:

[0130] Step 1002: Obtain the target switching frequency of the power conversion circuit switching transistor.

[0131] For example, the programmable logic device 311 performs calculations based on the AC side voltage to obtain the target switching frequency of the switching transistor.

[0132] Step 1004: Process 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 that the first switching frequency is greater than the second switching frequency.

[0133] The target feedback voltage is used to determine the target driving voltage for driving the switch to turn on based on the target feedback voltage. The amplitude of the target driving voltage is negatively correlated with the amplitude of the target feedback voltage. The switching frequency of the switch changes with the amplitude of the AC side voltage of the power conversion circuit.

[0134] In some embodiments, the target switching frequency is processed according to the second mapping relationship by the programmable logic device 311 to obtain the target feedback voltage amplitude, and the second duty cycle voltage is obtained based on the target feedback voltage amplitude; the second duty cycle voltage is filtered by the third filter circuit to obtain the target feedback voltage.

[0135] In an exemplary embodiment, a computer device is provided. This computer device may be a first microcontroller 121 in a power converter, a programmable logic device 311 in a power converter, or a third microcontroller; its internal structure diagram may be as shown in Figure 11. The computer device includes a processor, memory, input / output interfaces (I / O), and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is connected to the system bus via the I / O interfaces. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database of the computer device stores data that needs to be stored and retrieved when executing the pole welding control method. The I / O interfaces of the computer device are used for exchanging information between the processor and external devices. The communication interface of the computer device is used for communicating with external terminals via a network connection. When the computer program is executed by the processor, it implements at least some steps of a switching transistor drive voltage control method.

[0136] Those skilled in the art will understand that the structure shown in Figure 8 is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or may combine certain components, or may have different component arrangements.

[0137] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0138] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0139] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0140] In one exemplary embodiment, a power converter is provided. The power converter includes a switch drive voltage control circuit 100 and a power conversion circuit 200 provided in the above embodiment, wherein the switch drive voltage control circuit 100 is connected to the drive terminals of each switch in the power conversion circuit 200.

[0141] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media 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), magnetic 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. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0142] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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.

[0143] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A switching transistor drive voltage control circuit, wherein, The switching transistor drive voltage control circuit is used to connect to each switching transistor in the power conversion circuit. The switching transistor drive voltage control circuit includes: a first sampling circuit, a first feedback circuit, a power supply circuit, and a drive circuit. The first sampling circuit is used to sample the AC side voltage of the power conversion circuit to obtain the target sampling voltage; The first feedback circuit is used to process the target sampled 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 sampled voltage is not greater than the amplitude of the feedback voltage corresponding to the second sampled voltage, and the amplitude of the first sampled voltage is greater than the amplitude of the second sampled voltage. The power supply circuit is used to output a target power supply voltage based on the target feedback voltage, and the amplitude of the target power supply voltage is negatively correlated with the amplitude of the target feedback voltage. The driving circuit is used to output a target driving voltage based on the target power supply voltage to drive the switching transistor to conduct, wherein the switching frequency of the switching transistor varies with the magnitude of the AC side voltage.

2. The switching transistor drive voltage control circuit according to claim 1, wherein, The first feedback circuit includes: A first microcontroller, the input terminal of which is connected to the output terminal of the sampling circuit, and the output terminal of which is connected to the feedback input terminal of the power supply circuit.

3. The switching transistor drive voltage control circuit according to claim 2, wherein, The output terminal of the first microcontroller includes the digital-to-analog output terminal of the first microcontroller; The first microcontroller is used to process the target sampled voltage according to the first mapping relationship, and output the target feedback voltage through the digital-to-analog output terminal.

4. The switching transistor drive voltage control circuit according to any one of claims 2-3, wherein, The output terminal of the first microcontroller includes a duty cycle output terminal; the feedback circuit further includes a first filter circuit, the input terminal of the first filter circuit is connected to the duty cycle output terminal, and the output terminal of the first filter circuit is connected to the feedback input terminal of the power supply circuit. The first microcontroller is used to process the target sampled voltage according to the first mapping relationship, and output a first duty cycle voltage through the duty cycle output terminal; The first filter circuit is used to filter the first duty cycle voltage to obtain the target feedback voltage.

5. The switching transistor drive voltage control circuit according to any one of claims 1-4, wherein, The first mapping relationship includes a linear relationship between the amplitude of the feedback voltage and the amplitude of the sampling voltage.

6. The switching transistor drive voltage control circuit according to any one of claims 1-5, wherein, The first mapping relationship includes a non-linear relationship between the amplitude of the feedback voltage and the amplitude of the sampling voltage.

7. The switching transistor drive voltage control circuit according to any one of claims 1-6, wherein, The first feedback circuit includes a rectifier circuit and a second filter circuit, wherein, The rectifier circuit is used to rectify and phase-shift the target sampled voltage to obtain the rectified voltage. The second filter circuit is used to filter and amplify the rectified voltage to obtain the target feedback voltage.

8. The switching transistor drive voltage control circuit according to any one of claims 1-7, wherein, The power supply circuit includes an auxiliary power chip, a first resistor, a second resistor, and a third resistor; wherein, The output terminal of the auxiliary power chip is connected to the first terminal of the first resistor, and the feedback input terminal of the auxiliary power chip is connected to the second terminal of the first resistor, the first terminal of the second resistor, and the first terminal of the third resistor. The second terminal 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 switching transistor drive voltage control circuit, wherein, The switching transistor drive voltage control circuit is used to connect to each switching transistor in the power conversion circuit. The switching transistor drive voltage control circuit includes: a second feedback circuit, a power supply circuit, and a drive circuit. The second feedback circuit is used to obtain the target switching frequency of the switching transistor and process it 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. The power supply circuit is used to output a target power supply voltage based on the target feedback voltage, and the amplitude of the target power supply voltage is negatively correlated with the amplitude of the target feedback voltage. The driving circuit is used to output a target driving voltage based on the target power supply voltage to drive the switching transistor to conduct, wherein the switching frequency of the switching transistor varies with the magnitude of the AC side voltage of the power conversion circuit.

10. The switching transistor drive voltage control circuit according to claim 9, wherein, The second feedback circuit includes a programmable logic device and a third filter circuit. The output of the third filter circuit is connected to the digital output of the programmable logic device, and the output of the third filter circuit is also connected to the feedback input of the power supply circuit. The programmable logic device is used to acquire the target switching frequency, process it according to the second mapping relationship based on the target switching frequency, and output the second duty cycle voltage through the digital output terminal; The third filter circuit is used to filter the second duty cycle voltage to obtain the target feedback voltage.

11. A method for controlling the driving voltage of a switching transistor, wherein, The method includes: Obtain the target sampling voltage corresponding to the AC side voltage of the power conversion circuit; The target sampling voltage is mapped 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 target feedback voltage is used to determine the target driving voltage for driving the switch to turn on, and the amplitude of the target driving voltage is negatively correlated with the amplitude of the target feedback voltage. The switching frequency of the switch varies with the amplitude of the AC side voltage.

12. A method for controlling the driving voltage of a switching transistor, wherein, The method includes: Obtain the target switching frequency of the switching transistor in the power conversion circuit; The target switching frequency is processed 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. The target feedback voltage is used to determine the target driving voltage for driving the switch to turn on, and the amplitude of the target driving voltage is negatively correlated with the amplitude of the target feedback voltage. The switching frequency of the switch changes with the amplitude of the AC side voltage of the power conversion circuit.

13. A power converter, wherein, The power converter includes a switching transistor drive voltage control circuit and a power conversion circuit as described in any one of claims 1-10; The switching transistor drive voltage control circuit is connected to the drive terminals of each switching transistor in the power conversion circuit.

14. A method for controlling the driving voltage of a switching transistor, wherein, The method includes: The AC side voltage of the power conversion circuit is sampled to obtain the target sampling voltage; The target driving voltage is determined based on the target sampling voltage; wherein the target driving voltage is used to drive the switching transistor in the power conversion circuit to conduct, the switching frequency of the switching transistor varies with the amplitude of the AC side voltage, and the target driving voltage is positively correlated with the target sampling voltage.

15. The method according to claim 14, wherein, Determining the target driving voltage based on the target sampled voltage includes: Determine the target feedback voltage based on the target sampling voltage; The target power supply voltage is determined based on the target feedback voltage; wherein the amplitude of the target power supply voltage and the amplitude of the target feedback voltage are negatively correlated. The target drive voltage is determined based on the target power supply voltage.

16. The method according to claim 15, wherein, Determining the target feedback voltage based on the target sampled voltage includes: The target sampling voltage is processed according to a 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.

17. The method according to claim 16, wherein, The step of processing the target sampled voltage according to the first mapping relationship to obtain the target feedback voltage includes: Based on the target sampled voltage, the first duty cycle voltage is obtained by processing it according to the first mapping relationship; The first duty cycle voltage is filtered to obtain the target feedback voltage.

18. The method according to claim 17, wherein, The first mapping relationship includes a linear relationship between the amplitude of the feedback voltage and the amplitude of the sampling voltage.

19. The method according to claim 17 or 18, wherein, The first mapping relationship includes a non-linear relationship between the amplitude of the feedback voltage and the amplitude of the sampling voltage.

20. The method according to any one of claims 15-19, wherein, Determining the target feedback voltage based on the target sampled voltage includes: The target sampled voltage is rectified and phase-shifted to obtain the rectified voltage; The rectified voltage is filtered and amplified to obtain the target feedback voltage.

21. A method for controlling the driving voltage of a switching transistor, wherein, The method further includes: Obtain the target switching frequency of the switching transistor in the power conversion circuit; The target switching frequency is processed 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. The target driving voltage is determined based on the target feedback voltage; wherein the target driving voltage is used to drive the switching transistor in the power conversion circuit to conduct.

22. A switching transistor drive voltage control circuit, wherein, The switching transistor drive voltage control circuit includes a first sampling circuit and a drive circuit, wherein the first sampling circuit and the drive circuit are directly or indirectly connected. The switching transistor drive voltage control circuit is used to execute the switching transistor drive voltage control method according to any one of claims 14-20.

23. A switching transistor drive voltage control circuit, wherein, The switching transistor drive voltage control circuit includes a second feedback circuit and a drive circuit, wherein the second feedback circuit and the drive circuit are directly or indirectly connected. The switching transistor drive voltage control circuit is used to execute the switching transistor drive voltage control method of claim 21.

24. A power converter, wherein, The power converter includes the switching transistor drive voltage control circuit and the power conversion circuit as described in any one of claims 22-23; The switching transistor drive voltage control circuit is connected to the drive terminals of each switching transistor in the power conversion circuit.

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