Driving circuit of power converter and control method of power converter

Abstract

The invention discloses a driving circuit of a power converter and a control method of the power converter, and belongs to the technical field of power electronics. The driving circuit comprises a driving signal transmission unit; the push-pull circuit comprises a switch tube module and a capacitor module; one end of the driving impedance network is connected to the load end, and the other end of the driving impedance network is used for being connected with a power conversion circuit of a power converter; and the capacitance adjusting unit is connected with the capacitance module, and the capacitance adjusting unit is used for adjusting the capacitance value of the capacitance module so as to adjust the driving rate of the driving circuit for driving the power conversion circuit. According to the drive circuit, the capacitance value of the capacitor module in the push-pull circuit is adjusted, so that the drive rate is adjusted, the response is quick, the loading capacity is high, gate oscillation is effectively avoided, and the operation performance and stability of the power converter are ensured.

Description

Technical Field

[0001] The present application belongs to the field of power electronics technology, and in particular relates to a driving circuit of a power converter and a control method of a power converter. Background Art

[0002] A power converter is a power conversion device that can convert electrical energy from one form to another to meet the power requirements of different devices or systems. It is widely used in power systems, electronic equipment, industrial control and other fields. In a power converter, the drive circuit is a key component that connects the control circuit and the power transistor. The drive circuit drives the power transistor to achieve power conversion by amplifying the control signal.

[0003] To ensure the stability and safety of the power converter operation, the voltage stress of the power transistor needs to be kept lower than its maximum tolerance during the power conversion process. The driving rate of the drive circuit can be reduced to suppress the voltage of the power transistor from rising or falling too quickly, so that the voltage stress is below the limit value. At the same time, in the working condition where the voltage stress is significantly lower than the maximum tolerance, the driving rate of the drive circuit can be increased to reduce the voltage-current overlap time in the power transistor and the voltage-current overlap time of the drive circuit, thereby reducing the loss of the power transistor and the drive circuit.

[0004] The current drive rate regulation method has a slow response speed, limited load capacity, and is prone to cause power transistor gate oscillation, affecting the performance and stability of the power converter operation. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a driving circuit of a power converter and a control method of a power converter, which can quickly respond to and adjust the driving rate, have strong load capacity, effectively avoid gate oscillation, and ensure the performance and stability of the power converter operation.

[0006] In a first aspect, the present application provides a driving circuit of a power converter, comprising:

[0007] A driving signal transmission unit;

[0008] A push-pull circuit, the push-pull circuit comprising a switch tube module and a capacitor module, the switch tube module comprising at least two target switch tubes, one end of the drive signal transmission unit is connected to the base of the at least two target switch tubes, the emitters of the at least two target switch tubes are connected to form a load end, the switch tube module is connected to the capacitor module to form a high level end and a low level end, the capacitor module comprises one or more target capacitors, and a plurality of the target capacitors are connected in series;

[0009] A driving impedance network, one end of which is connected to the load end, and the other end of which is used to be connected to a power conversion circuit of a power converter;

[0010] A capacitance adjustment unit, wherein the capacitance adjustment unit is connected to the capacitance module, and the capacitance adjustment unit is used to adjust the capacitance of the capacitance module so as to adjust the driving rate of the driving circuit driving the power conversion circuit.

[0011] According to the driving circuit of the power converter of the present application, a capacitor adjustment unit is set in the driving circuit to adjust the capacitance of the capacitor module in the push-pull circuit to achieve adjustment of the driving rate. This method has low cost and strong adaptability, can quickly respond to adjust the driving rate, has strong load capacity, effectively avoids gate oscillation, and ensures the performance and stability of the power converter operation.

[0012] According to one embodiment of the present application, the capacitance adjustment unit includes a first capacitance branch connected in parallel with the target capacitance, and the first capacitance branch includes a first capacitor and a first switch connected in series;

[0013] When the first switch is closed and the first capacitor branch is turned on, the drive circuit is in a first drive mode; when the first switch is opened and the first capacitor branch is turned off, the drive circuit is in a second drive mode; the drive rate of the first drive mode is greater than the drive rate of the second drive mode.

[0014] According to an embodiment of the present application, the capacitance adjustment unit includes a second capacitor connected in series with the target capacitance and a second switch connected in parallel with the second capacitor;

[0015] When the second switch is disconnected and the second capacitor is connected, the drive circuit is in a first drive mode; when the second switch is closed and the second capacitor is disconnected, the drive circuit is in a second drive mode; the drive rate of the first drive mode is greater than the drive rate of the second drive mode.

[0016] According to one embodiment of the present application, the capacitor module includes the target capacitor with a variable capacitance, and the capacitor adjustment unit is used to adjust the capacitance of the target capacitor with a variable capacitance to adjust the driving rate of the drive circuit driving the power conversion circuit.

[0017] According to one embodiment of the present application, when the capacitance of the target capacitor with variable capacitance is adjusted so that the capacitance of the capacitor module is greater than a first capacitance threshold, the driving circuit is in a first driving mode; when the capacitance of the target capacitor with variable capacitance is adjusted so that the capacitance of the capacitor module is less than a second capacitance threshold, the driving circuit is in a second driving mode; the driving rate of the first driving mode is greater than the driving rate of the second driving mode, and the second capacitance threshold is less than or equal to the first capacitance threshold.

[0018] According to an embodiment of the present application, the capacitance of the capacitor module is positively correlated with the driving speed of the power conversion circuit.

[0019] According to an embodiment of the present application, a voltage limiting unit is further included. The voltage limiting unit is connected between the driving impedance network and the power conversion circuit, and the voltage limiting unit is used to limit the voltage of the power conversion circuit.

[0020] According to an embodiment of the present application, the voltage limiting unit includes one or more of a resistive device, a capacitive device, a unidirectional conductive device, a bidirectional conductive device, a Zener diode, and a voltage stabilizing source.

[0021] According to an embodiment of the present application, the push-pull circuit further includes: a voltage stabilizing module, the voltage stabilizing module includes one or more voltage stabilizing units, and the voltage stabilizing unit is connected in parallel with the target capacitor.

[0022] According to an embodiment of the present application, the voltage stabilizing unit is a voltage stabilizing diode or a resistor having a resistance value greater than a target resistance threshold.

[0023] In a second aspect, the present application provides a power converter, comprising:

[0024] Control circuit;

[0025] The driving circuit of the power converter as described in the first aspect above, wherein the driving signal transmission unit of the driving circuit is connected to the control circuit;

[0026] A power conversion circuit is connected to the drive circuit, and the drive circuit is used to process the drive signal output by the control circuit and output the processed drive signal to the power conversion circuit to drive the power conversion circuit to perform power conversion.

[0027] According to the power converter of the present application, a capacitor adjustment unit is provided in the driving circuit to adjust the capacitance of the capacitor module in the push-pull circuit to achieve adjustment of the driving rate. This method has low cost and strong adaptability, can quickly respond to and adjust the driving rate, has strong load capacity, effectively avoids gate oscillation, and ensures the performance and stability of the power converter operation.

[0028] In a third aspect, the present application provides a control method for a power converter, the control method being applied to the power converter described in the second aspect above, the control method comprising:

[0029] Obtaining predicted voltage stress of a power conversion circuit;

[0030] When the predicted voltage stress is less than a first stress reference threshold, controlling the driving circuit to operate in a first driving mode;

[0031] When the predicted voltage stress is greater than the second stress reference threshold, the driving circuit is controlled to operate in the second driving mode, the first stress reference threshold is less than the second stress reference threshold, and the driving rate of the first driving mode is greater than the driving rate of the second driving mode.

[0032] According to the control method of the power converter of the present application, by comparing the predicted voltage stress with the preset reference threshold, the power converter is controlled to operate in a driving mode with different driving speeds according to the comparison result, with high stability and strong adaptability. The capacitance of the capacitor module in the push-pull circuit is adjusted using a capacitor adjustment unit to achieve adjustment of the driving speed. The method has low cost and strong adaptability, can quickly respond to adjust the driving speed, has strong load capacity, effectively avoids gate oscillation, and ensures the performance and stability of the power converter operation.

[0033] According to one embodiment of the present application, the predicted voltage stress is determined based on at least one of the current bus voltage of the DC bus to which the power converter is connected, the current conversion power of the power converter, the current current of the power conversion circuit and the current temperature of the power converter.

[0034] In a fourth aspect, the present application provides a power supply device, including:

[0035] A power converter as described in the second aspect above.

[0036] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0038] Figure 1 This is one of the structural schematic diagrams of the driving circuit of the power converter provided in the embodiment of the present application;

[0039] Figure 2 This is a second structural schematic diagram of a driving circuit of a power converter provided in an embodiment of the present application;

[0040] Figure 3 This is the third structural schematic diagram of the driving circuit of the power converter provided in the embodiment of the present application;

[0041] Figure 4 This is a fourth structural schematic diagram of a driving circuit of a power converter provided in an embodiment of the present application;

[0042] Figure 5 This is a fifth structural diagram of a driving circuit of a power converter provided in an embodiment of the present application;

[0043] Figure 6 This is the sixth structural schematic diagram of the driving circuit of the power converter provided in the embodiment of the present application;

[0044] Figure 7 This is the seventh structural schematic diagram of the driving circuit of the power converter provided in the embodiment of the present application;

[0045] Figure 8 It is one of the equivalent schematic diagrams of the driving circuit provided in the embodiment of the present application;

[0046] Fig. 9 This is one of the driving circuit simulation waveform schematic diagrams provided in the embodiment of the present application;

[0047] Fig.10 This is the second equivalent schematic diagram of the driving circuit provided in the embodiment of the present application;

[0048] Fig.11 This is the third equivalent schematic diagram of the driving circuit provided in the embodiment of the present application;

[0049] Fig.12 This is the second schematic diagram of the driving circuit simulation waveform provided in the embodiment of the present application;

[0050] Fig.13 This is the fourth equivalent schematic diagram of the driving circuit provided in the embodiment of the present application;

[0051] Fig.14 This is the third schematic diagram of the driving circuit simulation waveform provided in the embodiment of the present application;

[0052] Fig.15 This is the fifth equivalent schematic diagram of the driving circuit provided in the embodiment of the present application;

[0053] Fig.16 This is the sixth equivalent schematic diagram of the driving circuit provided in the embodiment of the present application;

[0054] Fig.17 This is the fourth schematic diagram of the driving circuit simulation waveform provided in the embodiment of the present application;

[0055] Fig.18It is one of the flow charts of the control method of the power converter provided in the embodiment of the present application;

[0056] Fig.19 This is a second flow chart of a method for controlling a power converter provided in an embodiment of the present application;

[0057] Fig. 20 This is a third flow chart of a method for controlling a power converter provided in an embodiment of the present application;

[0058] Fig.21 It is a schematic diagram of the structure of the power converter provided in the embodiment of the present application.

[0059] Reference numerals:

[0060] Power converter 10, control circuit 100, drive circuit 200, drive signal transmission unit 210, target switch tube 221, target capacitor 222, voltage stabilizing unit 223, load end 224, high level end 225, low level end 226, drive impedance network 230, first capacitor 241, first switch 242, second capacitor 251, second switch 252, voltage limiting unit 260, power conversion circuit 300. DETAILED DESCRIPTION

[0061] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0062] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0063] In the related art, there are several ways to adjust the driving speed:

[0064] First, the driving impedance unit is adjusted to adjust the driving rate. The current on the driving impedance unit is between the signal level and the power level, requiring the control unit to have a strong load capacity. At the same time, directly adjusting the driving impedance unit may cause gate oscillation of the power transistor and affect the stable operation of the system.

[0065] Secondly, the driving voltage is adjusted to adjust the driving speed. The driving voltage is filtered by a large-capacity capacitor, and the voltage change rate is slow, making it difficult to quickly respond to the driving speed adjustment requirements.

[0066] Third, adding multiple driving voltages to provide driving rate adjustment capability and introducing multiple driving voltage branches may cause some branches to be idle, increase power conversion costs, and reduce power density.

[0067] The current drive rate regulation method has a slow response speed and is prone to cause power transistor gate oscillation, affecting the performance and stability of the power converter operation.

[0068] In conjunction with the accompanying drawings, the drive circuit 200 of the power converter 10, the power converter 10, the control method of the power converter 10 and the power supply device provided in the embodiment of the present application are described in detail through specific embodiments and their application scenarios.

[0069] The driving circuit 200 of the power converter 10 in the embodiment of the present application can quickly respond to and adjust the driving rate, has a strong load capacity, effectively avoids gate oscillation, and ensures the performance and stability of the power converter 10.

[0070] like Figure 1 As shown, the driving circuit 200 includes: a driving signal transmission unit 210, a push-pull circuit, a driving impedance network 230 and a capacitance adjustment unit.

[0071] Among them, the drive signal transmission unit 210 is connected to the control circuit 100 of the power converter 10, and the drive signal transmission unit 210 plays the role of transmitting the drive signal. The functions of the drive signal transmission unit 210 include but are not limited to transmitting, modulating, demodulating, buffering, stabilizing, etc. the drive signal from the control circuit 100.

[0072] The push-pull circuit includes a switch tube module and a capacitor module. The switch tube module includes at least two target switch tubes 221. One end of the driving signal transmission unit 210 is connected to the base of at least two target switch tubes 221. The emitters of at least two target switch tubes 221 are connected to form a load end 224. The switch tube module is connected to the capacitor module to form a high level end 225 and a low level end 226. The capacitor module includes one or more target capacitors 222, and multiple target capacitors 222 are connected in series.

[0073] Among them, at least two target switch tubes 221 exist in the push-pull circuit in a push-pull manner, and different target switch tubes 221 are responsible for waveform amplification tasks of different cycles; the target capacitor 222 of the capacitor module is used to stabilize the driving voltage of the driving circuit 200.

[0074] In actual implementation, the number of target switch tubes 221 in the switch tube module and the number of target capacitors 222 in the capacitor module may be the same or different.

[0075] For example, Figure 1 As shown, the switch tube module includes two target switch tubes 221, and the capacitor module includes two target capacitors 222. The two target capacitors 222 are connected in series and are located at Figure 1 The target switch tube 221 at the top and the Figure 1 The target capacitor 222 above is connected to form a high level terminal 225, located at Figure 1 The target switch tube 221 below is located Figure 1 The target capacitor 222 at the bottom is connected to form a low level terminal, and the emitters of the two target switch tubes 221 are connected to form a load terminal 224 .

[0076] For another example, the switch tube module includes two target switch tubes 221, the capacitor module includes a target capacitor 222, the emitters of the two target switch tubes 221 are connected to form a load end 224, one target switch tube 221 is connected to one end of the target capacitor 222 to form a high level end 225, and the other target switch tube 221 is connected to the other end of the target capacitor 222 to form a low level end 226.

[0077] It should be noted that when the driving voltage cannot be stabilized, it is difficult to adjust the driving rate. The capacitor module has at least one target capacitor 222, and the target capacitor 222 can stabilize the driving voltage so that the driving circuit 200 can adjust the driving rate.

[0078] In this embodiment, one end of the driving impedance network 230 is connected to the load end 224 , and the other end of the driving impedance network 230 is used to connect to the power conversion circuit 300 of the power converter 10 .

[0079] In actual implementation, the other end of the driving impedance network 230 is connected to the gate of the power transistor in the power conversion circuit 300 .

[0080] The drive signal transmission unit 210 is connected to the push-pull circuit, and the push-pull circuit is connected to the drive impedance network 230. The drive signal transmission unit 210 transmits the drive signal to the push-pull circuit. The push-pull circuit can convert the input drive signal into high and low levels that can directly drive the power conversion circuit 300. The high and low levels generated by the push-pull circuit are transmitted through the drive impedance network 230.

[0081] In actual implementation, the power conversion circuit 300 includes a power transistor, the gate of the power transistor is connected to the drive circuit 200, and the drive impedance network 230 plays a role in regulating and optimizing signal transmission to ensure that the gate of the power transistor can receive a drive signal of appropriate strength.

[0082] It can be understood that the control circuit 100, the drive signal transmission unit 210, the push-pull circuit, the drive impedance network 230 and other components work together to achieve effective driving of the power transistor. The control circuit 100 generates a drive signal according to system requirements and operating conditions. The drive signal generated by the control circuit 100 is transmitted to the drive signal transmission unit 210. The drive signal transmission unit 210 processes the drive signal to adapt to different application scenarios. The push-pull circuit converts the input signal into high and low levels that can directly drive the gate of the power transistor. The high and low levels are transmitted through the drive impedance network 230. The gate of the power transistor receives the processed drive signal to achieve switching control of the power transistor.

[0083] In this embodiment, the driving circuit 200 of the power converter 10 is provided with a capacitance adjustment unit, which is connected to the capacitance module. The capacitance adjustment unit is used to adjust the capacitance of the capacitance module to adjust the driving rate of the driving circuit 200 driving the power conversion circuit 300.

[0084] It should be noted that the high and low levels of the push-pull circuit and the voltage of the capacitor module are transmitted through the driving impedance network 230, and the capacitance of the capacitor module is adjusted by the capacitor adjustment unit. The driving signal transmitted to the power conversion circuit 300 by the driving impedance network 230 is changed to realize the control of the driving rate. Compared with the method of adjusting the driving rate by driving the impedance unit or the driving voltage in the related art, the embodiment of the present application adjusts the driving rate by adjusting the capacitance of the capacitor module and adjusting the driving voltage-stabilizing capacitor, and realizes the adjustment by using the original circuit parameters, which has low cost, strong adaptability, and can quickly respond to the adjustment requirements of the driving rate.

[0085] For example, Figure 1 As shown, the capacitor module includes two target capacitors 222, which are connected in series. The high and low levels generated by the push-pull circuit and the voltage between the midpoints of the two target capacitors 222 are transmitted through the driving impedance network 230. The capacitor adjustment unit adjusts the capacitance of the capacitor module and adjusts the driving rate of the power conversion circuit 300.

[0086] According to the driving circuit 200 of the power converter 10 provided in the embodiment of the present application, a capacitor adjustment unit is set in the driving circuit 200 to adjust the capacitance of the capacitor module in the push-pull circuit to achieve adjustment of the driving rate. This method has low cost and strong adaptability, can quickly respond to and adjust the driving rate, has strong load capacity, effectively avoids gate oscillation, and ensures the performance and stability of the power converter 10.

[0087] The following specifically describes how the capacitance adjustment unit in the embodiment of the present application adjusts the capacitance of the capacitance module in the push-pull circuit from several different implementation perspectives.

[0088] 1. The capacitance adjustment unit may include a first capacitor 241 and a first switch 242 , and the capacitance of the capacitance module in the push-pull circuit may be adjusted through the first switch 242 .

[0089] In some embodiments, the capacitance adjustment unit includes a first capacitance branch connected in parallel with the target capacitance 222 , and the first capacitance branch includes a first capacitor 241 and a first switch 242 connected in series.

[0090] When the first switch 242 is closed and the first capacitor branch is turned on, the drive circuit 200 is in the first drive mode; when the first switch 242 is opened and the first capacitor branch is turned off, the drive circuit 200 is in the second drive mode; the driving rate of the first drive mode is greater than the driving rate of the second drive mode.

[0091] The first switch 242 is a unit with switching capability, including but not limited to an equivalent switch composed of semiconductor devices, an equivalent switch with controlled resistance, a relay, and the like.

[0092] In this embodiment, the first capacitor 241 and the first switch 242 connected in series form a first capacitor branch, and the first capacitor branch is connected in parallel to the target capacitor 222 of the capacitor module. When the first switch 242 is closed, the first capacitor 241 is connected to the capacitor module to increase the capacitance of the capacitor module. When the first switch 242 is disconnected, the first capacitor 241 is cut out from the capacitor module to reduce the capacitance of the capacitor module. The capacitance of the capacitor module is changed through the first capacitor 241.

[0093] It should be noted that the first capacitor 241 can be a capacitor with a preset capacitance. The first capacitor branch is connected in parallel with the target capacitor 222. When the first switch 242 is closed, the drive circuit 200 is in a first drive mode with a high drive rate. The capacitance of the first capacitor 241 and the capacitance of the target capacitor 222 connected in parallel with the first capacitor 241 satisfy that the total capacitance of the first capacitor 241 and the target capacitor 222 connected in parallel is greater than the capacitance of the target capacitor 222.

[0094] For example, the capacitance of the first capacitor 241 is x farads, and the capacitance of the target capacitor 222 is y farads. When the first switch 242 is closed, the first capacitor 241 and the target capacitor 222 are connected in parallel, and the total capacitance is (x*y) / (x+y) farads, (x*y) / (x+y) farads>y farads, so that when the first switch 242 is closed, the driving circuit 200 can be in the first driving mode with a high driving rate.

[0095] In actual implementation, the capacitor module includes two target capacitors 222, which are connected in series. The capacitor adjustment unit can have one or two first capacitor branches. When there is one first capacitor branch, one of the two target capacitors 222 is connected in parallel with the first capacitor 241, and the first switch 242 controls the connection and disconnection of the first capacitor 241.

[0096] For example, Figure 1 As shown, two target capacitors 222 are connected in series and are located at Figure 1 The upper target capacitor 222 is connected in parallel with the first capacitor 241 . The first capacitor 241 and the first switch 242 are connected in series to form a first capacitor branch. The capacitance of the capacitor module is adjusted through the first capacitor branch.

[0097] For example, Figure 2 As shown, two target capacitors 222 are connected in series and are located at Figure 2 The target capacitor 222 at the bottom is connected in parallel with the first capacitor 241 . The first capacitor 241 and the first switch 242 are connected in series to form a first capacitor branch. The capacitance of the capacitor module is adjusted through the first capacitor branch.

[0098] In actual implementation, the control circuit 100 may be connected to the first switch 242 for communication ( Figure 1 and Figure 2 As shown by the dashed line with an arrow in the middle), the control circuit 100 can control the closing and opening of the first switch 242 to achieve control of the driving rate.

[0099] In this embodiment, when the first switch 242 is closed and the first capacitor branch is turned on, the first capacitor 241 is connected to the capacitor module to speed up the driving rate of the power conversion circuit 300, so that the driving circuit 200 operates in the first driving mode with a high driving rate.

[0100] When the first switch 242 is disconnected and the first capacitor branch is turned off, the first capacitor 241 is switched out of the capacitor module, reducing the driving rate of the power conversion circuit 300, so that the driving circuit 200 operates in the second driving mode with a low driving rate.

[0101] 2. The capacitance adjustment unit may include a second capacitor 251 and a second switch 252, and the capacitance of the capacitance module in the push-pull circuit is adjusted by the second switch 252.

[0102] In some embodiments, the capacitance adjustment unit includes a second capacitor 251 connected in series with the target capacitor 222 and a second switch 252 connected in parallel with the second capacitor 251 .

[0103] When the second switch 252 is disconnected and the second capacitor 251 is connected, the driving circuit 200 is in the first driving mode; when the second switch 252 is closed and the second capacitor 251 is disconnected, the driving circuit 200 is in the second driving mode; the driving rate of the first driving mode is greater than the driving rate of the second driving mode.

[0104] The second switch 252 is a unit with switching capability, including but not limited to an equivalent switch composed of semiconductor devices, an equivalent switch with controlled resistance, a relay, and the like.

[0105] In this embodiment, the second capacitor 251 and the second switch 252 connected in parallel form a second capacitor branch, and the second capacitor branch is connected in series to the capacitor module. When the second switch 252 is disconnected, the second capacitor branch is connected to the capacitor module to increase the capacitance of the capacitor module. When the second switch 252 is closed, the second capacitor branch is bypassed to reduce the capacitance of the capacitor module, and the capacitance of the capacitor module is changed through the second capacitor 251.

[0106] It can be understood that the second capacitor 251 can be a capacitor with a preset capacitance. The second capacitor 251 is connected in parallel with the target capacitor 222. When the second switch 252 is disconnected, the second capacitor 251 is connected to the capacitor module, the capacitance of the capacitor module increases, and the driving circuit 200 is in the first driving mode with a high driving rate.

[0107] In actual implementation, the capacitor module includes two target capacitors 222, which are connected in series. The capacitor adjustment unit can have a second capacitor branch, one of the two target capacitors 222 is connected in series with the second capacitor 251, and the access and bypass of the second capacitor 251 are controlled by the second switch 252.

[0108] For example, Figure 3 As shown, two target capacitors 222 are connected in series and are located at Figure 3 The upper target capacitor 222 is connected in series with the second capacitor 251 , and the second capacitor 251 is connected in parallel with the second switch 252 to form a second capacitor branch, and the capacitance of the capacitor module is adjusted through the second capacitor branch.

[0109] For example, Figure 4 As shown, two target capacitors 222 are connected in series and are located at Figure 4 The target capacitor 222 at the bottom is connected in series with the second capacitor 251 . The second capacitor 251 and the second switch 252 are connected in parallel to form a second capacitor branch. The capacitance of the capacitor module is adjusted through the second capacitor branch.

[0110] In actual implementation, the control circuit 100 may be connected to the second switch 252 for communication ( Figure 3 and Figure 4As shown by the dashed line with an arrow in the middle), the control circuit 100 can control the closing and opening of the second switch 252 to achieve control of the driving rate.

[0111] In this embodiment, when the second switch 252 is disconnected, the second capacitor 251 is connected to the capacitor module to increase the driving rate of the power conversion circuit 300, so that the driving circuit 200 operates in the first driving mode with a high driving rate.

[0112] When the second switch 252 is closed, the second capacitor 251 is bypassed, and the driving rate of the power conversion circuit 300 is reduced, so that the driving circuit 200 operates in the second driving mode with a low driving rate.

[0113] 3. The capacitor module includes a target capacitor 222 with a variable capacitance. By adjusting the capacitance of the target capacitor 222, the capacitance of the capacitor module in the push-pull circuit can be adjusted.

[0114] In some embodiments, the capacitor module includes a target capacitor 222 with a variable capacitance, and the capacitance adjustment unit is used to adjust the capacitance of the target capacitor 222 with a variable capacitance to adjust the driving rate of the driving circuit 200 driving the power conversion circuit 300 .

[0115] In actual implementation, when the capacitor module includes multiple target capacitors 222 , the capacitance of at least one of the multiple target capacitors 222 is variable, that is, the capacitor module has at least one variable capacitor.

[0116] For example, Figure 5 As shown, two target capacitors 222 are connected in series and are located at Figure 5 The target capacitor 222 at the top is a variable capacitor. The capacitance value of the target capacitor 222 can be adjusted within a certain range. The capacitance value of the capacitor module can be adjusted through the variable capacitor.

[0117] For example, Figure 6 As shown, two target capacitors 222 are connected in series and are located at Figure 6 The target capacitor 222 below is a variable capacitor. The capacitance value of the target capacitor 222 can be adjusted within a certain range. The capacitance value of the capacitor module is adjusted by the variable capacitor.

[0118] In actual implementation, the capacitance adjustment unit may be a functional module in the control circuit 100, and the control circuit 100 may be communicatively connected with the variable capacitance target capacitor 222 ( Figure 5 and Figure 6 As shown by the dashed line with an arrow in the middle), the capacitance adjustment unit can adjust the target capacitance 222 with a variable capacitance to achieve control of the driving rate.

[0119] In some embodiments, when the capacitance of the variable-capacitance target capacitor 222 is adjusted so that the capacitance of the capacitor module is greater than a first capacitance threshold, the driving circuit 200 is in the first driving mode.

[0120] In some embodiments, when the capacitance of the variable-capacitance target capacitor 222 is adjusted so that the capacitance of the capacitor module is less than the second capacitance threshold, the driving circuit 200 is in the second driving mode.

[0121] The driving rate of the first driving mode is greater than the driving rate of the second driving mode, and the second capacitance threshold is less than or equal to the first capacitance threshold.

[0122] In this embodiment, the first capacitance threshold and the second capacitance threshold are preset capacitance critical values. When the capacitance of the variable capacitance target capacitor 222 is adjusted so that the capacitance of the capacitor module is greater than the first capacitance threshold, it indicates that the capacitance of the capacitor module is large and the driving circuit 200 operates in the first driving mode with a high driving rate.

[0123] When the capacitance of the variable-capacitance target capacitor 222 is adjusted so that the capacitance of the capacitor module is less than the second capacitance threshold, it indicates that the capacitance of the capacitor module is small, and the driving circuit 200 operates in the second driving mode with a low driving rate.

[0124] It should be noted that the capacitance of the capacitor module is positively correlated with the driving speed of the power conversion circuit 300 .

[0125] The high and low levels of the push-pull circuit and the voltage of the capacitor module are transmitted through the driving impedance network 230, and the capacitance of the capacitor module is adjusted by the capacitor adjustment unit. When the capacitance of the capacitor module is large, the driving voltage transmitted to the power conversion circuit 300 by the driving impedance network 230 is large, and the driving rate of the power conversion circuit 300 is high. When the capacitance of the capacitor module is small, the driving voltage transmitted to the power conversion circuit 300 by the driving impedance network 230 is small, and the driving rate of the power conversion circuit 300 is low.

[0126] It is understandable that when the capacitor adjustment unit is working, a new capacitor (the first capacitor 241 or the second capacitor 251) is added or cut out in the capacitor module, or the capacitance of the target capacitor 222 (variable capacitor) in the capacitor module is changed. There may be a situation where the voltage fails to be established on the capacitor in time, resulting in voltage instability, which may affect the stability of the driving circuit 200 and the reliability of the components.

[0127] In some embodiments, the driving circuit 200 of the power converter 10 further includes a voltage limiting unit 260 . The voltage limiting unit 260 is connected between the driving impedance network 230 and the power conversion circuit 300 . The voltage limiting unit 260 is used to limit the voltage of the power conversion circuit 300 .

[0128] In this embodiment, if Figure 7 As shown, one or more voltage limiting units 260 are added between the driving impedance network 230 and the power conversion circuit 300 to limit the voltage of the power conversion circuit 300, thereby avoiding voltage instability, preventing the gate voltage of the power transistor in the power conversion circuit 300 from being too high or too low, ensuring the normal operation of the power transistor, and improving the reliability of the power transistor.

[0129] In some embodiments, the voltage limiting unit 260 includes one or more of a resistive device, a capacitive device, a unidirectional conductive device, a bidirectional conductive device, a Zener diode, and a voltage stabilizing source.

[0130] In this embodiment, the voltage limiting unit 260 can be one of a resistive device, a capacitive device, a unidirectional conductive device, a bidirectional conductive device, a Zener diode and a voltage stabilizer, or it can be a combination of multiple resistive devices, capacitive devices, a unidirectional conductive device, a bidirectional conductive device, a Zener diode and a voltage stabilizer.

[0131] In some embodiments, the push-pull circuit further includes a voltage stabilization module, which includes one or more voltage stabilization units 223 , and the voltage stabilization unit 223 is connected in parallel with the target capacitor 222 .

[0132] It is understandable that the voltage stabilizing unit 223 is connected in parallel with the target capacitor 222 , and the voltage stabilizing unit 223 can stabilize the voltage of the target capacitor 222 .

[0133] In actual implementation, the number of target capacitors 222 in the capacitor module and the number of voltage stabilizing units 223 in the voltage stabilizing module may be the same or different.

[0134] For example, Figure 1 As shown, the capacitor module includes two target capacitors 222 , which are connected in series. The voltage stabilizing module includes two voltage stabilizing units 223 , and each voltage stabilizing unit 223 is connected in parallel with one target capacitor 222 .

[0135] It should be noted that when the capacitor module has only one target capacitor 222 , the push-pull circuit may not be provided with a voltage stabilizing module, and the voltage of the target capacitor 222 is determined by the power supply of the driving circuit 200 .

[0136] When the capacitor module has two target capacitors 222 , one of the two target capacitors 222 is connected in parallel with the voltage stabilizing unit 223 , and the voltage of the target capacitor 222 not connected in parallel with the voltage stabilizing unit 223 is determined by subtracting the power supply of the driving circuit 200 from the voltage stabilizing unit 223 .

[0137] In some embodiments, the voltage stabilizing unit 223 is a voltage stabilizing diode or a resistor with a resistance greater than a target resistance threshold.

[0138] The target resistance threshold is a preset resistance critical value.

[0139] For example, if the target resistance threshold is 100 ohms, the voltage stabilizing unit 223 may use a voltage stabilizing tube, or a resistor with a resistance greater than 100 ohms.

[0140] The driving circuit 200 of the power converter 10 of the embodiment of the present application adjusts the driving rate by adjusting the capacitance of the capacitor module in the push-pull circuit. There are multiple implementation methods for adjusting the capacitance, which are low-cost and highly adaptable. The following is an analysis and explanation of how to adjust the driving rate by changing the capacitance of the capacitor module.

[0141] It should be noted that, to simplify the analysis, the driving impedance network 230 and the power transistor are simplified to a series circuit of a resistor Rg and a capacitor Cg respectively.

[0142] 1. Change the capacitance of the capacitor module and adjust the driving negative voltage.

[0143] like Figure 8 As shown, Q1 and Q2 are target switch tubes 221 of the push-pull circuit, C1 and C2 are target capacitors 222 of the push-pull circuit, and the voltage stabilizing module includes a resistor R1 and a voltage stabilizing tube Z2.

[0144] The resistance of R1 is relatively large. During the switching transient process, the current on R1 is much smaller than the current on C1, C2 and Cg. The current on R1 is equivalent to 0, and the Zener diode Z2 plays a clamping role in the steady state. When u2 decreases due to the discharge of C2, u2 < clamping voltage Uz, and the current on Z2 is considered to be equivalent to 0.

[0145] Fig. 9 Shown Figure 8 Schematic diagram of simulation waveform of the equivalent circuit shown.

[0146] The circuit state when Q1 is off (shown by the dotted line) and Q2 is on is as follows: Fig.10 As shown:

[0147] When Cg discharges, its voltage ug changes from UC-Uz to -Un, and the charge change is Cg(UC–Uz+Un);

[0148] C1 is charged, its voltage u1 changes from UC-Uz to UC-Un, and the charge change is C1(Uz-Un);

[0149] C2 discharges, its voltage u2 changes from Uz to Un, and the charge change is C2 (Uz-Un).

[0150] The current flowing through Cg is divided into C1 and C2, the current on R1 and Z2 is equivalent to 0, the charge change of Cg is equal to the charge change of C1 and C2, and the charge change relationship is obtained:

[0151] (C1+C2)(Uz-Un)=Cg(UC+Un-Uz)

[0152] Among them, the solution to Un is:

[0153]

[0154] That is, Un decreases as C1+C2 decreases. In actual circuits, this formula may not be strictly followed due to the influence of stray parameters and environmental factors, but the relationship that Un decreases as C1+C2 decreases remains unchanged.

[0155] In addition, when When , due to the reverse conduction of Z2, Un will not decrease further, and Un will be maintained at 0 due to the clamping effect of Z2.

[0156] Similarly, the circuit state when Q1 is on and Q2 is off (shown by the dotted line) is as follows: Fig.11 As shown, the charge changes in the same way as Fig.10 The operating conditions shown are completely opposite, but the relationship that the charge change of Cg is equal to the charge change of C1 and C2 remains unchanged, and the relationship that Un decreases as C1+C2 decreases (ie, positive correlation) also remains unchanged.

[0157] The circuit is simulated, and the voltage ug waveform of Cg when C1+C2 changes is as follows: Fig.12 As shown, as C1+C2 decreases from 10uF to 1uF, the negative pressure of the voltage ug of Cg gradually approaches 0, and the driving rate gradually decreases.

[0158] In this embodiment, when C2 is clamped, the driving negative voltage can be adjusted and the driving rate can be changed by changing C1+C2 (the capacitance of C1+C2 is the capacitance of the capacitor module).

[0159] 2. Change the capacitance of the capacitor module and adjust the positive driving voltage.

[0160] like Fig.13 As shown, Q1 and Q2 are target switch tubes 221 of the push-pull circuit, C1 and C2 are target capacitors 222 of the push-pull circuit, and the voltage stabilizing module includes a voltage stabilizing tube Z1 and a resistor R2.

[0161] The resistance of R2 is relatively large. During the switching transient process, the current on R2 is much smaller than the current on C1, C2 and Cg. The current on R2 is equivalent to 0, and the Zener diode Z1 plays a clamping role in the steady state. When u1 decreases due to the discharge of C1, u1<clamping voltage Uz, and the current on Z1 is considered to be equivalent to 0.

[0162] Fig.14 Shown Fig.13Schematic diagram of simulation waveform of the equivalent circuit shown.

[0163] The circuit state when Q1 is on and Q2 is off (shown by the dotted line) is as follows Fig.15 As shown:

[0164] When Cg is charged, its voltage ug changes from -UC+Uz ​​to Up, and the charge change is Cg(Up+UC-Uz);

[0165] C1 discharges, its voltage u1 changes from Uz to Up, and the charge change is C1 (Uz-Up);

[0166] C2 is charged, its voltage u2 changes from UC-Uz to UC-Up, and the charge change is C2 (Uz-Up).

[0167] The current flowing through Cg is divided into C1 and C2, the current on R2 and Z1 is equivalent to 0, the charge change of Cg is equal to the charge change of C1 and C2, and the charge change relationship is:

[0168] (C1+C2)(Uz-Up)=Cg(Up-UC+Uz)

[0169] Among them, Up is solved as:

[0170]

[0171] That is, Up decreases as C1+C2 decreases. In actual circuits, this formula may not be strictly followed due to the influence of stray parameters and environmental factors, but the relationship that Up decreases as C1+C2 decreases remains unchanged.

[0172] In addition, when When , due to the reverse conduction of Z1, Up will not decrease further, and Up will be maintained at 0 due to the clamping effect of Z1.

[0173] Similarly, the circuit state when Q2 is on and Q1 is off (shown by the dotted line) is as follows: Fig.16 As shown, the charge changes in the same way as Fig.15 The operating conditions shown are completely opposite, but the relationship that the charge change of Cg is equal to the charge change of C1 and C2 remains unchanged, and the relationship that Up decreases as C1+C2 decreases also remains unchanged.

[0174] The circuit is simulated, and the voltage ug waveform of Cg when C1+C2 changes is as follows: Fig.17 As shown, as C1+C2 decreases from 10uF to 1uF, the positive voltage of the voltage ug of Cg gradually decreases, and the driving rate gradually decreases.

[0175] In this embodiment, when C2 is clamped, the driving positive voltage can be adjusted and the driving rate can be changed by changing C1+C2 (the capacitance of C1+C2 is the capacitance of the capacitor module).

[0176] In the embodiment of the present application, when the capacitance of the capacitor module is large, the driving voltage transmitted by the driving impedance network 230 to the power conversion circuit 300 is large, and the driving rate is high. When the capacitance of the capacitor module is small, the driving voltage transmitted by the driving impedance network 230 to the power conversion circuit 300 is small, and the driving rate is low. By adjusting the capacitance, the driving rate control is achieved, the response speed is fast, and the load capacity is strong, which can ensure the performance and stability of the power converter 10.

[0177] The embodiment of the present application also provides a power converter 10 .

[0178] like Fig.21 As shown, the power converter 10 includes: a control circuit 100 , a drive circuit 200 of the power converter 10 as described above, and a power conversion circuit 300 .

[0179] The driving signal transmission unit 210 of the driving circuit 200 is connected to the control circuit 100, and the power conversion circuit 300 is connected to the driving circuit 200. The driving circuit 200 is used to process the driving signal output by the control circuit 100 and output the processed driving signal to the power conversion circuit 300 to drive the power conversion circuit 300 to perform power conversion.

[0180] It can be understood that the control circuit 100, the drive signal transmission unit 210, the push-pull circuit, the drive impedance network 230 and other components work together to achieve effective driving of the power transistor. The control circuit 100 generates a drive signal according to system requirements and operating conditions. The drive signal generated by the control circuit 100 is transmitted to the drive signal transmission unit 210. The drive signal transmission unit 210 processes the drive signal to adapt to different application scenarios. The push-pull circuit converts the input signal into high and low levels that can directly drive the gate of the power transistor. The high and low levels are transmitted through the drive impedance network 230. The gate of the power transistor receives the processed drive signal to achieve switching control of the power transistor.

[0181] In this embodiment, a capacitance adjustment unit is provided in the driving circuit 200 , and the capacitance adjustment unit adjusts the capacitance of the capacitance module of the push-pull circuit to adjust the driving rate of the driving circuit 200 driving the power conversion circuit 300 .

[0182] According to the power converter 10 provided in the embodiment of the present application, a capacitor adjustment unit is set in the driving circuit 200 to adjust the capacitance of the capacitor module in the push-pull circuit to achieve adjustment of the driving rate. This method has low cost and strong adaptability, can quickly respond to and adjust the driving rate, has strong load capacity, effectively avoids gate oscillation, and ensures the performance and stability of the power converter 10.

[0183] An embodiment of the present application further provides a power supply device, which includes the power converter 10 as described above.

[0184] The power converter 10 of the power supply device is used to realize power conversion between DC voltage and AC voltage. The power supply device can be an inverter, a converter and other devices.

[0185] According to the power supply device provided in the embodiment of the present application, a capacitor adjustment unit is set in the driving circuit 200 to adjust the capacitance of the capacitor module in the push-pull circuit to achieve adjustment of the driving rate. This has low cost and strong adaptability, can quickly respond to adjust the driving rate, has strong load capacity, effectively avoids gate oscillation, and ensures the performance and stability of the power converter 10.

[0186] The embodiment of the present application further provides a control method of a power converter 10 , which is applied to the above-mentioned power converter 10 .

[0187] like Fig.18 and Fig.19 As shown, the control method of the power converter 10 includes: step 1810 , step 1820 and step 1830 .

[0188] Step 1810 : Obtain the predicted voltage stress of the power conversion circuit 300 .

[0189] In this embodiment, the predicted voltage stress of the power conversion circuit 300 is the voltage stress that the power transistors in the power conversion circuit 300 are expected to withstand.

[0190] The control circuit 100 compares the predicted voltage stress with a preset voltage stress reference threshold, and based on the comparison result, controls the driving circuit 200 to operate in a first driving mode with a high driving rate or a second driving mode with a low driving rate.

[0191] The preset voltage stress reference threshold may include a first stress reference threshold and a second stress reference threshold, the first stress reference threshold is smaller than the second stress reference threshold, and the driving rate of the first driving mode is greater than the driving rate of the second driving mode.

[0192] Step 1820 : When the predicted voltage stress is less than the first stress reference threshold, control the driving circuit 200 to operate in the first driving mode.

[0193] In this step, when the predicted voltage stress is less than the first stress reference threshold, it indicates that the voltage stress of the power transistor is low, and the drive circuit 200 operates in the first drive mode. Increasing the drive rate can reduce the loss of the power transistor and the drive circuit 200.

[0194] Step 1830 : When the predicted voltage stress is greater than the second stress reference threshold, control the driving circuit 200 to operate in the second driving mode.

[0195] In this step, when the predicted voltage stress is greater than the second stress reference threshold, it indicates that the voltage stress of the power transistor is high, and the drive circuit 200 operates in the second drive mode. Reducing the drive rate can reduce the voltage stress and ensure stable operation of the power converter 10.

[0196] It should be noted that the first stress reference threshold and the second stress reference threshold are obtained based on experiments, simulations or calculation formulas. The first stress reference threshold is greater than the second stress reference threshold. The control of the driving rate exhibits a hysteresis characteristic, which helps to suppress noise interference and enhance the stability of the system.

[0197] In actual implementation, the first stress reference threshold may be equal to the second stress reference threshold to simplify the comparison logic of the control circuit 100 .

[0198] It can be understood that after the predicted voltage stress of the power conversion circuit 300 is obtained in step 1810, according to the result of comparing the predicted voltage stress with the preset voltage stress reference threshold, such as Fig.18 As shown, the first driving mode of step 1820 can be entered, or as shown in FIG. Fig.19 As shown, the second driving mode can be entered into step 1830.

[0199] For example, Fig. 20 As shown, when the driving circuit 200 is in the first driving mode with a high driving rate, if the predicted voltage stress of the power transistor is higher than the second stress reference threshold, the driving circuit 200 is switched to the second driving mode with a low driving rate to reduce the voltage stress. If the predicted voltage stress does not exceed the second stress reference threshold, the driving circuit 200 can continue to operate in the first driving mode with a high driving rate.

[0200] When the driving circuit 200 is in the second driving mode with a low driving rate, if the predicted voltage stress of the power transistor is lower than the first stress reference threshold, the driving circuit 200 is switched to the first driving mode with a high driving rate to reduce the loss of the power transistor and the driving circuit 200. If the predicted voltage stress is not lower than the first stress reference threshold, the driving circuit 200 can continue to operate in the second driving mode with a low driving rate.

[0201] It is understandable that a capacitance adjustment unit is provided in the driving circuit 200 to change the capacitance of the capacitance module in the push-pull circuit, adjust the driving rate, and realize the switching between the first driving mode and the second driving mode.

[0202] For example, Figure 1 As shown, two target capacitors 222 are connected in series and are located at Figure 1 The upper target capacitor 222 is connected in parallel with the first capacitor 241 . The first capacitor 241 and the first switch 242 are connected in series to form a first capacitor branch. The capacitance of the capacitor module is adjusted through the first capacitor branch.

[0203] When the first switch 242 is closed and the first capacitor branch is turned on, the first capacitor 241 is connected to the capacitor module, which speeds up the driving rate of the power conversion circuit 300, so that the driving circuit 200 operates in the first driving mode with a high driving rate; when the first switch 242 is disconnected and the first capacitor branch is turned off, the first capacitor 241 is cut out of the capacitor module, which reduces the driving rate of the power conversion circuit 300, so that the driving circuit 200 operates in the second driving mode with a low driving rate.

[0204] According to the control method of the power converter 10 provided in the embodiment of the present application, by comparing the predicted voltage stress with the preset reference threshold, the power converter 10 is controlled to operate in a driving mode with different driving speeds according to the comparison result. It has high stability and strong adaptability. The capacitance of the capacitor module in the push-pull circuit is adjusted by using a capacitor adjustment unit to adjust the driving speed. It has low cost and strong adaptability. It can quickly respond to adjust the driving speed, has strong load capacity, effectively avoids gate oscillation, and ensures the performance and stability of the power converter 10.

[0205] In some embodiments, the predicted voltage stress is determined based on at least one of a current bus voltage of a DC bus to which the power converter 10 is connected, a current conversion power of the power converter 10 , a current current of the power conversion circuit 300 , and a current temperature of the power converter 10 .

[0206] In this embodiment, the predicted voltage stress of the power conversion circuit 300 can be obtained by predicting one or more of the current bus voltage of the DC bus connected to the power converter 10, the current conversion power of the power converter 10, the current current of the power conversion circuit 300 and the current temperature of the power converter 10.

[0207] In actual implementation, the predicted voltage stress of the power conversion circuit 300 can be predicted using the current bus voltage.

[0208] For example, Fig.21As shown, the power converter 10 has a sampling feedback function (shown by the dotted line in the figure), which measures the DC bus voltage of the power conversion circuit 300 (directly measures or indirectly measures a voltage proportional to the bus voltage), obtains the voltage information of the DC bus, transmits it to the control circuit 100, and calculates the expected predicted voltage stress of the power transistor.

[0209] For example, the control circuit 100 obtains the DC bus voltage value Vdc, and predicts the voltage stress of the power transistor in combination with experimental data, simulation results or calculation formulas to obtain the predicted voltage stress Vdc+ΔV, where ΔV is the incremental value of the voltage stress.

[0210] In actual implementation, the predicted voltage stress of the power conversion circuit 300 can also be predicted by the current conversion power, the current current or the current temperature. The predicted voltage stress can also be predicted by comprehensive analysis using the current bus voltage, the current conversion power, the current current and the current temperature.

[0211] An embodiment of the present application also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the various processes of the control method embodiment of the above-mentioned power converter 10 are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0212] The processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk or an optical disk.

[0213] An embodiment of the present application further provides a computer program product, including a computer program, which implements the control method of the power converter 10 when executed by a processor.

[0214] The processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk or an optical disk.

[0215] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the control method embodiment of the above-mentioned power converter 10, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0216] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0217] It should be noted that, in this article, the term "comprises", "includes" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the method and device in the embodiment of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0218] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, a disk, or an optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0219] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

[0220] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0221] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A driving circuit for a power converter, characterized in that: include: A driving signal transmission unit; A push-pull circuit, the push-pull circuit comprising a switch tube module and a capacitor module, the switch tube module comprising at least two target switch tubes, one end of the drive signal transmission unit is connected to the base of the at least two target switch tubes, the emitters of the at least two target switch tubes are connected to form a load end, the switch tube module is connected to the capacitor module to form a high level end and a low level end, the capacitor module comprises one or more target capacitors, and a plurality of the target capacitors are connected in series; A driving impedance network, one end of which is connected to the load end, and the other end of which is used to be connected to a power conversion circuit of a power converter; A capacitance adjustment unit, wherein the capacitance adjustment unit is connected to the capacitance module, and the capacitance adjustment unit is used to adjust the capacitance of the capacitance module so as to adjust the driving rate of the driving circuit driving the power conversion circuit.

2. The driving circuit of the power converter according to claim 1, characterized in that: The capacitance adjustment unit includes a first capacitance branch connected in parallel with the target capacitance, wherein the first capacitance branch includes a first capacitor and a first switch connected in series; When the first switch is closed and the first capacitor branch is turned on, the driving circuit is in the first driving mode; When the first switch is turned off and the first capacitor branch is turned off, the driving circuit is in a second driving mode; The driving rate of the first driving mode is greater than the driving rate of the second driving mode.

3. The driving circuit of the power converter according to claim 1, characterized in that: The capacitance adjustment unit includes a second capacitor connected in series with the target capacitance and a second switch connected in parallel with the second capacitor; When the second switch is disconnected and the second capacitor is connected, the driving circuit is in the first driving mode; When the second switch is closed and the second capacitor is cut out, the driving circuit is in a second driving mode; The driving rate of the first driving mode is greater than the driving rate of the second driving mode.

4. The driving circuit of the power converter according to claim 1, characterized in that: The capacitor module includes the target capacitor with a variable capacitance, and the capacitance adjustment unit is used to adjust the capacitance of the target capacitor with a variable capacitance so as to adjust the driving rate of the driving circuit driving the power conversion circuit.

5. The driving circuit of the power converter according to claim 4, characterized in that: When the capacitance of the target capacitor with variable capacitance is adjusted so that the capacitance of the capacitor module is greater than a first capacitance threshold, the driving circuit is in a first driving mode; when the capacitance of the target capacitor with variable capacitance is adjusted so that the capacitance of the capacitor module is less than a second capacitance threshold, the driving circuit is in a second driving mode; the driving rate of the first driving mode is greater than the driving rate of the second driving mode, and the second capacitance threshold is less than or equal to the first capacitance threshold.

6. The driving circuit of the power converter according to any one of claims 1 to 5, characterized in that: The capacitance of the capacitor module is positively correlated with the driving speed of the power conversion circuit.

7. The driving circuit of the power converter according to any one of claims 1 to 5, characterized in that: It also includes a voltage limiting unit, which is connected between the driving impedance network and the power conversion circuit, and is used to limit the voltage of the power conversion circuit.

8. The driving circuit of the power converter according to claim 7, characterized in that: The voltage limiting unit includes one or more of a resistive device, a capacitive device, a unidirectional conductive device, a bidirectional conductive device, a Zener diode and a voltage stabilizing source.

9. The driving circuit of the power converter according to any one of claims 1 to 5, characterized in that: The push-pull circuit further includes: a voltage stabilizing module, wherein the voltage stabilizing module includes one or more voltage stabilizing units, and the voltage stabilizing units are connected in parallel with the target capacitor.

10. The driving circuit of the power converter according to claim 9, characterized in that: The voltage stabilizing unit is a voltage stabilizing tube or a resistor whose resistance is greater than a target resistance threshold.

11. A power converter, characterized in that: include: Control circuit; The driving circuit of the power converter according to any one of claims 1 to 10, wherein the driving signal transmission unit of the driving circuit is connected to the control circuit; A power conversion circuit is connected to the drive circuit, and the drive circuit is used to process the drive signal output by the control circuit and output the processed drive signal to the power conversion circuit to drive the power conversion circuit to perform power conversion.

12. A method for controlling a power converter, characterized in that: The control method is applied to the power converter according to claim 11, and the control method comprises: Obtaining predicted voltage stress of a power conversion circuit; When the predicted voltage stress is less than a first stress reference threshold, controlling the driving circuit to operate in a first driving mode; When the predicted voltage stress is greater than the second stress reference threshold, the driving circuit is controlled to operate in the second driving mode, the first stress reference threshold is less than the second stress reference threshold, and the driving rate of the first driving mode is greater than the driving rate of the second driving mode.

13. The control method of the power converter according to claim 12, characterized in that: The predicted voltage stress is determined based on at least one of a current bus voltage of a DC bus to which the power converter is connected, a current conversion power of the power converter, a current current of the power conversion circuit, and a current temperature of the power converter.

14. A power supply device, characterized in that: include: The power converter as claimed in claim 11.

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