Silicon carbide MOSFET driving voltage control method and device

Abstract

The invention relates to the technical field of silicon carbide metal oxide semiconductor field effect transistor (MOSFET) driving, and particularly provides a silicon carbide metal oxide semiconductor field effect transistor (MOSFET) driving voltage control method and device, and the method comprises the steps: a driving circuit outputs a driving voltage to a grid electrode of a silicon carbide MOSFET; the driving voltage control circuit outputs an intermediate driving voltage to the source electrode of the silicon carbide MOSFET based on the power supply voltage; the driving circuit and the driving voltage control circuit are both powered by a power supply. According to the technical scheme provided by the invention, a single power supply is divided into two voltages, positive and negative voltages are applied to the grid electrode of the device, the negative voltage can be stabilized when the power supply voltage is too high, the grid-source negative voltage of the device is prevented from being too high, and the positive voltage is stabilized when the power supply voltage is relatively low. When the device is turned on, enough forward voltage is applied to enable the device to be reliably turned on.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon carbide MOSFET driving, and in particular to a silicon carbide MOSFET driving voltage control method and device. Background Art

[0002] Silicon carbide MOSFET has been regarded as an "ideal device" and is highly anticipated due to its high withstand voltage, low loss, high efficiency and other characteristics. The use of silicon carbide devices can significantly achieve small and light, high energy efficiency and strong driving force system performance. The driver is an important hub connecting silicon carbide devices and low-voltage controllers. It mainly realizes the opening and closing of silicon carbide devices, as well as protection under various abnormal conditions. It is a core device to ensure the efficient and reliable operation of the power conversion system, provides high-speed and reliable switching control for power devices, and is the main controllable unit of the transient switching process of power devices.

[0003] When a sufficiently large forward drive voltage (such as +15V) is applied between the gate and source of the SiC MOSFET, the SiC device will be turned on and current can flow through it; when the voltage between the gate and source is 0, the device will be turned off and the current will be blocked. In practical applications, when the drain potential of the SiC device changes rapidly, the higher du / dt will raise the gate voltage through the junction capacitance, which may cause the device to be turned on by mistake. Summary of the invention

[0004] In order to overcome the above-mentioned defects, the present invention proposes a method and device for controlling a driving voltage of a silicon carbide MOSFET.

[0005] In a first aspect, a method for controlling a driving voltage of a silicon carbide MOSFET is provided, the method comprising:

[0006] The driving circuit outputs a driving voltage to the gate of the silicon carbide MOSFET;

[0007] The driving voltage control circuit outputs an intermediate driving voltage to the source of the silicon carbide MOSFET based on the supply voltage;

[0008] Wherein, the driving circuit and the driving voltage control circuit are both powered by a power supply.

[0009] Preferably, the driving voltage control circuit comprises:

[0010] A voltage divider circuit, used for outputting an intermediate voltage based on a power supply voltage of a power supply;

[0011] The power amplifier circuit is used to perform power amplification on the intermediate voltage to obtain an intermediate driving voltage, and output the intermediate driving voltage to the source of the silicon carbide MOSFET.

[0012] Further, the outputting of the intermediate voltage based on the power supply voltage of the power supply includes:

[0013] When the supply voltage exceeds a preset value, stabilizing the output intermediate voltage at a first voltage threshold;

[0014] When the difference between the power supply voltage and the intermediate voltage is lower than a second voltage threshold, the difference between the power supply voltage and the intermediate voltage is stabilized at the second voltage threshold.

[0015] Furthermore, the preset value is the sum of the first threshold and the second threshold.

[0016] Furthermore, the first threshold is a stable turn-off voltage of the silicon carbide MOSFET, and the second threshold is a stable turn-on voltage of the silicon carbide MOSFET.

[0017] Further, the voltage divider circuit includes: a voltage stabilizing diode D1, a resistor R1, a resistor R2, an operational amplifier U1, an operational amplifier U2, a current source I1 and a MOSFET device M1;

[0018] The power supply is connected to the voltage stabilizing diode D1 and the resistor R1 in sequence and then grounded;

[0019] The power supply is connected to the current source I1, the resistor R2 and the source of the MOSFET device M1 in sequence;

[0020] The source of the MOSFET device M1 is grounded;

[0021] The connection point between the voltage stabilizing diode D1 and the resistor R1 is connected to the reverse input terminal of the operational amplifier U1;

[0022] The positive input terminal of the operational amplifier U1 is connected to the drain of the MOSFET device M1;

[0023] The output terminal of the operational amplifier U1 is connected to the gate of the MOSFET device M1;

[0024] The drain of the MOSFET device M1 is connected to the connection point between the current source I1 and the resistor R2 and then connected to the positive input terminal of the operational amplifier U2;

[0025] The inverting input terminal of the operational amplifier U2 is connected to the output terminal of the operational amplifier U2;

[0026] The power supply port of the operational amplifier U2 is connected to the power supply and the ground wire respectively.

[0027] Further, the power amplifier circuit includes: a transistor T1 and a transistor T2;

[0028] The collector of the transistor T1 is connected to a power supply;

[0029] The emitter of the transistor T1 is connected to the emitter of the transistor T2;

[0030] The collector of the transistor T2 is grounded;

[0031] The base of the transistor T1 is connected to the base of the transistor T2;

[0032] The connection point between the base of the transistor T1 and the base of the transistor T2 is connected to the output end of the operational amplifier U2;

[0033] The connection point between the emitter of the transistor T1 and the emitter of the transistor T2 is the output end of the power amplifier circuit.

[0034] Furthermore, the transistor T1 is an NPN transistor, and the transistor T2 is a PNP transistor.

[0035] In a second aspect, a silicon carbide MOSFET driving voltage control device is provided, wherein the silicon carbide MOSFET driving voltage control device comprises:

[0036] A driving circuit, used for outputting a driving voltage to a gate of the silicon carbide MOSFET;

[0037] A driving voltage control circuit, used for outputting an intermediate driving voltage to a source of the silicon carbide MOSFET based on a supply voltage;

[0038] Wherein, the driving circuit and the driving voltage control circuit are both powered by a power supply.

[0039] Preferably, the driving voltage control circuit comprises:

[0040] A voltage divider circuit, used for outputting an intermediate voltage based on a power supply voltage of a power supply;

[0041] The power amplifier circuit is used to perform power amplification on the intermediate voltage to obtain an intermediate driving voltage, and output the intermediate driving voltage to the source of the silicon carbide MOSFET.

[0042] Further, the outputting of the intermediate voltage based on the power supply voltage of the power supply includes:

[0043] When the supply voltage exceeds a preset value, stabilizing the output intermediate voltage at a first voltage threshold;

[0044] When the difference between the power supply voltage and the intermediate voltage is lower than a second voltage threshold, the difference between the power supply voltage and the intermediate voltage is stabilized at the second voltage threshold.

[0045] Furthermore, the preset value is the sum of the first threshold and the second threshold.

[0046] Furthermore, the first threshold is a stable turn-off voltage of the silicon carbide MOSFET, and the second threshold is a stable turn-on voltage of the silicon carbide MOSFET.

[0047] Further, the voltage divider circuit includes: a voltage stabilizing diode D1, a resistor R1, a resistor R2, an operational amplifier U1, an operational amplifier U2, a current source I1 and a MOSFET device M1;

[0048] The power supply is connected to the voltage stabilizing diode D1 and the resistor R1 in sequence and then grounded;

[0049] The power supply is connected to the current source I1, the resistor R2 and the source of the MOSFET device M1 in sequence;

[0050] The source of the MOSFET device M1 is grounded;

[0051] The connection point between the voltage stabilizing diode D1 and the resistor R1 is connected to the reverse input terminal of the operational amplifier U1;

[0052] The positive input terminal of the operational amplifier U1 is connected to the drain of the MOSFET device M1;

[0053] The output terminal of the operational amplifier U1 is connected to the gate of the MOSFET device M1;

[0054] The drain of the MOSFET device M1 is connected to the connection point between the current source I1 and the resistor R2 and then connected to the positive input terminal of the operational amplifier U2;

[0055] The inverting input terminal of the operational amplifier U2 is connected to the output terminal of the operational amplifier U2;

[0056] The power supply port of the operational amplifier U2 is connected to the power supply and the ground wire respectively.

[0057] Further, the power amplifier circuit includes: a transistor T1 and a transistor T2;

[0058] The collector of the transistor T1 is connected to a power supply;

[0059] The emitter of the transistor T1 is connected to the emitter of the transistor T2;

[0060] The collector of the transistor T2 is grounded;

[0061] The base of the transistor T1 is connected to the base of the transistor T2;

[0062] The connection point between the base of the transistor T1 and the base of the transistor T2 is connected to the output end of the operational amplifier U2;

[0063] The connection point between the emitter of the transistor T1 and the emitter of the transistor T2 is the output end of the power amplifier circuit.

[0064] Furthermore, the transistor T1 is an NPN transistor, and the transistor T2 is a PNP transistor.

[0065] In a third aspect, a computer device is provided, comprising: one or more processors;

[0066] The processor is configured to execute one or more programs;

[0067] When the one or more programs are executed by the one or more processors, the silicon carbide MOSFET driving voltage control method is implemented.

[0068] In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed, the silicon carbide MOSFET driving voltage control method is implemented.

[0069] The above one or more technical solutions of the present invention have at least one or more of the following beneficial effects:

[0070] The present invention provides a method and device for controlling driving voltage of a silicon carbide MOSFET, comprising: a driving circuit outputting a driving voltage to the gate of the silicon carbide MOSFET; a driving voltage control circuit outputting an intermediate driving voltage to the source of the silicon carbide MOSFET based on a power supply voltage; wherein the driving circuit and the driving voltage control circuit are both powered by a power supply. The technical solution provided by the present invention divides a single power supply into two voltages, realizes the application of positive and negative dual voltages to the gate of the device, and can stabilize the negative voltage when the power supply voltage is too high, avoid excessively high negative voltage of the gate source of the device, and stabilize the positive voltage when the power supply voltage is low, and apply sufficient positive voltage when the device is turned on to make the device reliably turned on. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 1 is a schematic flow chart of the main steps of the silicon carbide MOSFET driving voltage control method according to an embodiment of the present invention;

[0072] Figure 2 1 is a schematic diagram of the principle of a silicon carbide MOSFET driving voltage control method according to an embodiment of the present invention;

[0073] Figure 3 4 is a circuit diagram of a silicon carbide MOSFET driving voltage control circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0074] The specific implementation modes of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0075] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0076] As disclosed in the background technology, silicon carbide MOSFET has been regarded as an "ideal device" and is highly anticipated due to its high withstand voltage, low loss, high efficiency and other characteristics. The use of silicon carbide devices can significantly achieve small and light, high energy efficiency and strong driving force system performance. The driver is an important hub connecting silicon carbide devices and low-voltage controllers. It mainly realizes the opening and closing of silicon carbide devices, as well as protection under various abnormal conditions. It is a core device to ensure the efficient and reliable operation of the power conversion system, provides high-speed and reliable switching control for power devices, and is the main controllable unit of the transient switching process of power devices.

[0077] When a sufficiently large forward drive voltage (such as +15V) is applied between the gate and source of the SiC MOSFET, the SiC device will be turned on and current can flow through it; when the voltage between the gate and source is 0, the device will be turned off and the current will be blocked. In practical applications, when the drain potential of the SiC device changes rapidly, the higher du / dt will raise the gate voltage through the junction capacitance, which may cause the device to be turned on by mistake.

[0078] In order to improve the above problems, the present invention provides a method and device for controlling driving voltage of silicon carbide MOSFET, including: a driving circuit outputs driving voltage to the gate of silicon carbide MOSFET; a driving voltage control circuit outputs an intermediate driving voltage to the source of silicon carbide MOSFET based on the power supply voltage; wherein the driving circuit and the driving voltage control circuit are both powered by a power supply. The technical solution provided by the present invention divides a single power supply into two voltages, realizes the application of positive and negative dual voltages to the gate of the device, and can stabilize the negative voltage when the power supply voltage is too high, avoid excessive negative voltage of the gate source of the device, and stabilize the positive voltage when the power supply voltage is low, and apply sufficient positive voltage when the device is turned on to make the device reliably turned on.

[0079] The above scheme is described in detail below.

[0080] Example 1

[0081] See attached Figure 1 , Figure 1FIG. 1 is a flow chart showing the main steps of a method for controlling a driving voltage of a silicon carbide MOSFET according to an embodiment of the present invention. Figure 1 As shown, the silicon carbide MOSFET driving voltage control method in the embodiment of the present invention mainly includes the following steps:

[0082] Step S101: the driving circuit outputs a driving voltage to the gate of the silicon carbide MOSFET;

[0083] Step S102: the driving voltage control circuit outputs an intermediate driving voltage to the source of the silicon carbide MOSFET based on the power supply voltage;

[0084] Wherein, the driving circuit and the driving voltage control circuit are both powered by a power supply.

[0085] In this embodiment, the driving voltage control circuit includes:

[0086] A voltage divider circuit, used for outputting an intermediate voltage based on a power supply voltage of a power supply;

[0087] The power amplifier circuit is used to perform power amplification on the intermediate voltage to obtain an intermediate driving voltage, and output the intermediate driving voltage to the source of the silicon carbide MOSFET.

[0088] In one embodiment, the outputting the intermediate voltage based on the power supply voltage of the power supply includes:

[0089] When the supply voltage exceeds a preset value, stabilizing the output intermediate voltage at a first voltage threshold;

[0090] When the difference between the power supply voltage and the intermediate voltage is lower than a second voltage threshold, the difference between the power supply voltage and the intermediate voltage is stabilized at the second voltage threshold.

[0091] In one implementation, the preset value is the sum of the first threshold and the second threshold.

[0092] In one embodiment, the first threshold is a stable turn-off voltage of the silicon carbide MOSFET, and the second threshold is a stable turn-on voltage of the silicon carbide MOSFET.

[0093] In a specific embodiment, Figure 2 As shown in the figure, the driving voltage control circuit is composed of a voltage divider circuit and a power amplifier circuit, which divides the power supply voltage VCC into two stable voltages and realizes power amplification. The intermediate potential VS is connected to the source of the SiC MOSFET. The driving circuit is powered by the power supply voltage, and its output is connected to the gate of the SiC MOSFET. The output voltage rails are VCC and GND. Therefore, for the gate source of the SiC MOSFET, the driving voltage is VCC-VS when it is turned on, and the driving voltage is -VS when it is turned off.

[0094] The voltage divider circuit is powered by VCC, and its function is to divide VCC into two stable voltages, and the middle voltage is connected to the power amplifier circuit. When VCC is high, the voltage divider circuit stabilizes VS at the first voltage threshold to ensure that the negative gate-source voltage when the SiC MOSFET is turned off does not exceed the safety threshold, and VCC-VS changes with the change of VCC. As VCC decreases, if VCC-VS decreases to the second voltage threshold, VCC-VS is stabilized at the second voltage threshold to ensure that there is enough positive gate-source voltage when the SiC MOSFET is turned on, so that the device can be fully turned on, and VS changes with VCC. At this time, VS is lower than the first voltage threshold.

[0095] The power amplifier circuit is powered by VCC, and its function is to make the output terminal VS follow the intermediate voltage divided by the voltage divider circuit and perform power amplification, so that the output terminal VS has a larger current output capacity. Its output terminal VS is connected to the source of the SiC MOSFET.

[0096] In one embodiment, the voltage divider circuit includes: a voltage stabilizing diode D1, a resistor R1, a resistor R2, an operational amplifier U1, an operational amplifier U2, a current source I1 and a MOSFET device M1;

[0097] The power supply is connected to the voltage stabilizing diode D1 and the resistor R1 in sequence and then grounded;

[0098] The power supply is connected to the current source I1, the resistor R2 and the source of the MOSFET device M1 in sequence;

[0099] The source of the MOSFET device M1 is grounded;

[0100] The connection point between the voltage stabilizing diode D1 and the resistor R1 is connected to the reverse input terminal of the operational amplifier U1;

[0101] The positive input terminal of the operational amplifier U1 is connected to the drain of the MOSFET device M1;

[0102] The output terminal of the operational amplifier U1 is connected to the gate of the MOSFET device M1;

[0103] The drain of the MOSFET device M1 is connected to the connection point between the current source I1 and the resistor R2 and then connected to the positive input terminal of the operational amplifier U2;

[0104] The inverting input terminal of the operational amplifier U2 is connected to the output terminal of the operational amplifier U2;

[0105] The power supply port of the operational amplifier U2 is connected to the power supply and the ground wire respectively.

[0106] In one embodiment, the power amplifier circuit includes: a transistor T1 and a transistor T2;

[0107] The collector of the transistor T1 is connected to a power supply;

[0108] The emitter of the transistor T1 is connected to the emitter of the transistor T2;

[0109] The collector of the transistor T2 is grounded;

[0110] The base of the transistor T1 is connected to the base of the transistor T2;

[0111] The connection point between the base of the transistor T1 and the base of the transistor T2 is connected to the output end of the operational amplifier U2;

[0112] The connection point between the emitter of the transistor T1 and the emitter of the transistor T2 is the output end of the power amplifier circuit.

[0113] In one implementation, the transistor T1 is an NPN transistor, and the transistor T2 is a PNP transistor.

[0114] In a specific embodiment, see Figure 3 , this embodiment is composed of a voltage stabilizing diode D1, resistors R1-R2, operational amplifiers U1-U2, a current source I1, a MOSFET M1, and transistors T1-T2. VCC is the power supply voltage, and VS is the output intermediate voltage. The first voltage threshold V1=I1*R2=5V, and the second voltage threshold is the voltage stabilizing value of the voltage stabilizing diode D1, which is 15V.

[0115] When VCC is higher than 20V, D1 reversely breaks down, and the voltage across it is 15V, then the voltage across resistor R1 is VCC-15V>5V. Since the voltage across resistor R2 is (I1-IM1)*R2, and IM1 is the current flowing through MOSFET M1, it can be seen that the maximum voltage across R2 is 5V. At this time, the output of operational amplifier U1 is 0V, M1 is in the off state, IM1 is 0, and the voltage of R2 is 5V. This voltage is output to the power amplifier circuit through the voltage follower formed by operational amplifier U2. The power amplifier circuit is composed of NPN transistor T1 and PNP transistor T2. The final VS output voltage is the first voltage threshold 5V (ignoring the base-emitter voltage of the transistor).

[0116] When VCC is lower than 20V and higher than 15V, D1 reversely breaks down, and the voltage across it is 15V, then the voltage across resistor R1 is VCC-15V<5V. At this time, the output of operational amplifier U1 will make M1 work in the linear region, then because there is current flowing through M1, the voltage of R2 drops from 5V to the voltage across R1, reaching a stable state. This voltage passes through the voltage follower and power amplifier circuit, and finally VS outputs the voltage of R1 (ignoring the base-emitter voltage of the transistor), and VCC-VS is the second voltage threshold of 15V.

[0117] Example 2

[0118] Based on the same inventive concept, the present invention also provides a silicon carbide MOSFET driving voltage control device, the silicon carbide MOSFET driving voltage control device comprising:

[0119] A driving circuit, used for outputting a driving voltage to a gate of the silicon carbide MOSFET;

[0120] A driving voltage control circuit, used for outputting an intermediate driving voltage to a source of the silicon carbide MOSFET based on a supply voltage;

[0121] Wherein, the driving circuit and the driving voltage control circuit are both powered by a power supply.

[0122] Preferably, the driving voltage control circuit comprises:

[0123] A voltage divider circuit, used for outputting an intermediate voltage based on a power supply voltage of a power supply;

[0124] The power amplifier circuit is used to perform power amplification on the intermediate voltage to obtain an intermediate driving voltage, and output the intermediate driving voltage to the source of the silicon carbide MOSFET.

[0125] Further, the outputting of the intermediate voltage based on the power supply voltage of the power supply includes:

[0126] When the supply voltage exceeds a preset value, stabilizing the output intermediate voltage at a first voltage threshold;

[0127] When the difference between the power supply voltage and the intermediate voltage is lower than a second voltage threshold, the difference between the power supply voltage and the intermediate voltage is stabilized at the second voltage threshold.

[0128] Furthermore, the preset value is the sum of the first threshold and the second threshold.

[0129] Furthermore, the first threshold is a stable turn-off voltage of the silicon carbide MOSFET, and the second threshold is a stable turn-on voltage of the silicon carbide MOSFET.

[0130] Further, the voltage divider circuit includes: a voltage stabilizing diode D1, a resistor R1, a resistor R2, an operational amplifier U1, an operational amplifier U2, a current source I1 and a MOSFET device M1;

[0131] The power supply is connected to the voltage stabilizing diode D1 and the resistor R1 in sequence and then grounded;

[0132] The power supply is connected to the current source I1, the resistor R2 and the source of the MOSFET device M1 in sequence;

[0133] The source of the MOSFET device M1 is grounded;

[0134] The connection point between the voltage stabilizing diode D1 and the resistor R1 is connected to the reverse input terminal of the operational amplifier U1;

[0135] The positive input terminal of the operational amplifier U1 is connected to the drain of the MOSFET device M1;

[0136] The output terminal of the operational amplifier U1 is connected to the gate of the MOSFET device M1;

[0137] The drain of the MOSFET device M1 is connected to the connection point between the current source I1 and the resistor R2 and then connected to the positive input terminal of the operational amplifier U2;

[0138] The inverting input terminal of the operational amplifier U2 is connected to the output terminal of the operational amplifier U2;

[0139] The power supply port of the operational amplifier U2 is connected to the power supply and the ground wire respectively.

[0140] Further, the power amplifier circuit includes: a transistor T1 and a transistor T2;

[0141] The collector of the transistor T1 is connected to a power supply;

[0142] The emitter of the transistor T1 is connected to the emitter of the transistor T2;

[0143] The collector of the transistor T2 is grounded;

[0144] The base of the transistor T1 is connected to the base of the transistor T2;

[0145] The connection point between the base of the transistor T1 and the base of the transistor T2 is connected to the output end of the operational amplifier U2;

[0146] The connection point between the emitter of the transistor T1 and the emitter of the transistor T2 is the output end of the power amplifier circuit.

[0147] Furthermore, the transistor T1 is an NPN transistor, and the transistor T2 is a PNP transistor.

[0148] Example 3

[0149] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function, so as to implement the steps of a silicon carbide MOSFET driving voltage control method in the above embodiment.

[0150] Example 4

[0151] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It can be understood that the computer-readable storage medium here can include both built-in storage media in a computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of a silicon carbide MOSFET drive voltage control method in the above embodiment.

[0152] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0153] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0154] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0155] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for controlling driving voltage of a silicon carbide MOSFET, characterized in that: The method comprises: The driving circuit outputs a driving voltage to the gate of the silicon carbide metal oxide semi-conductor field effect transistor MOSFET; The driving voltage control circuit outputs an intermediate driving voltage to the source of the silicon carbide MOSFET based on the supply voltage; Wherein, the driving circuit and the driving voltage control circuit are both powered by a power supply.

2. The method according to claim 1, characterized in that The driving voltage control circuit comprises: A voltage divider circuit, used for outputting an intermediate voltage based on a power supply voltage of a power supply; The power amplifier circuit is used to perform power amplification on the intermediate voltage to obtain an intermediate driving voltage, and output the intermediate driving voltage to the source of the silicon carbide MOSFET.

3. The method according to claim 2, characterized in that The outputting of the intermediate voltage based on the power supply voltage of the power supply comprises: When the supply voltage exceeds a preset value, stabilizing the output intermediate voltage at a first voltage threshold; When the difference between the power supply voltage and the intermediate voltage is lower than a second voltage threshold, the difference between the power supply voltage and the intermediate voltage is stabilized at the second voltage threshold.

4. The method according to claim 3, characterized in that The preset value is the sum of the first threshold and the second threshold.

5. The method according to claim 4, characterized in that The first threshold is a stable turn-off voltage of the silicon carbide MOSFET, and the second threshold is a stable turn-on voltage of the silicon carbide MOSFET.

6. The method according to claim 2, characterized in that The voltage divider circuit includes: a voltage stabilizing diode D1, a resistor R1, a resistor R2, an operational amplifier U1, an operational amplifier U2, a current source I1 and a MOSFET device M1; The power supply is connected to the voltage stabilizing diode D1 and the resistor R1 in sequence and then grounded; The power supply is connected to the current source I1, the resistor R2 and the source of the MOSFET device M1 in sequence; The source of the MOSFET device M1 is grounded; The connection point between the voltage stabilizing diode D1 and the resistor R1 is connected to the reverse input terminal of the operational amplifier U1; The positive input terminal of the operational amplifier U1 is connected to the drain of the MOSFET device M1; The output terminal of the operational amplifier U1 is connected to the gate of the MOSFET device M1; The drain of the MOSFET device M1 is connected to the connection point between the current source I1 and the resistor R2 and then connected to the positive input terminal of the operational amplifier U2; The inverting input terminal of the operational amplifier U2 is connected to the output terminal of the operational amplifier U2; The power supply port of the operational amplifier U2 is connected to the power supply and the ground wire respectively.

7. The method according to claim 6, characterized in that The power amplifier circuit comprises: a transistor T1 and a transistor T2; The collector of the transistor T1 is connected to a power supply; The emitter of the transistor T1 is connected to the emitter of the transistor T2; The collector of the transistor T2 is grounded; The base of the transistor T1 is connected to the base of the transistor T2; The connection point between the base of the transistor T1 and the base of the transistor T2 is connected to the output end of the operational amplifier U2; The connection point between the emitter of the transistor T1 and the emitter of the transistor T2 is the output end of the power amplifier circuit.

8. The method according to claim 7, characterized in that The transistor T1 is an NPN transistor, and the transistor T2 is a PNP transistor.

9. A silicon carbide MOSFET driving voltage control device, characterized in that: The device comprises: A driving circuit, used for outputting a driving voltage to a gate of the silicon carbide MOSFET; A driving voltage control circuit, used for outputting an intermediate driving voltage to a source of the silicon carbide MOSFET based on a supply voltage; Wherein, the driving circuit and the driving voltage control circuit are both powered by a power supply.

10. The device according to claim 9, characterized in that The driving voltage control circuit comprises: A voltage divider circuit, used for outputting an intermediate voltage based on a power supply voltage of a power supply; The power amplifier circuit is used to perform power amplification on the intermediate voltage to obtain an intermediate driving voltage, and output the intermediate driving voltage to the source of the silicon carbide MOSFET.

11. The device according to claim 10, characterized in that The outputting of the intermediate voltage based on the power supply voltage of the power supply comprises: When the supply voltage exceeds a preset value, stabilizing the output intermediate voltage at a first voltage threshold; When the difference between the power supply voltage and the intermediate voltage is lower than a second voltage threshold, the difference between the power supply voltage and the intermediate voltage is stabilized at the second voltage threshold.

12. The device according to claim 11, characterized in that The preset value is the sum of the first threshold and the second threshold.

13. The device according to claim 12, characterized in that The first threshold is a stable turn-off voltage of the silicon carbide MOSFET, and the second threshold is a stable turn-on voltage of the silicon carbide MOSFET.

14. The device according to claim 10, characterized in that The voltage divider circuit includes: a voltage stabilizing diode D1, a resistor R1, a resistor R2, an operational amplifier U1, an operational amplifier U2, a current source I1 and a MOSFET device M1; The power supply is connected to the voltage stabilizing diode D1 and the resistor R1 in sequence and then grounded; The power supply is connected to the current source I1, the resistor R2 and the source of the MOSFET device M1 in sequence; The source of the MOSFET device M1 is grounded; The connection point between the voltage stabilizing diode D1 and the resistor R1 is connected to the reverse input terminal of the operational amplifier U1; The positive input terminal of the operational amplifier U1 is connected to the drain of the MOSFET device M1; The output terminal of the operational amplifier U1 is connected to the gate of the MOSFET device M1; The drain of the MOSFET device M1 is connected to the connection point between the current source I1 and the resistor R2 and then connected to the positive input terminal of the operational amplifier U2; The inverting input terminal of the operational amplifier U2 is connected to the output terminal of the operational amplifier U2; The power supply port of the operational amplifier U2 is connected to the power supply and the ground wire respectively.

15. The device according to claim 14, characterized in that The power amplifier circuit comprises: a transistor T1 and a transistor T2; The collector of the transistor T1 is connected to a power supply; The emitter of the transistor T1 is connected to the emitter of the transistor T2; The collector of the transistor T2 is grounded; The base of the transistor T1 is connected to the base of the transistor T2; The connection point between the base of the transistor T1 and the base of the transistor T2 is connected to the output end of the operational amplifier U2; The connection point between the emitter of the transistor T1 and the emitter of the transistor T2 is the output end of the power amplifier circuit.

16. The device according to claim 15, characterized in that The transistor T1 is an NPN transistor, and the transistor T2 is a PNP transistor.

17. A computer device, characterized in that: include: one or more processors; The processor is configured to execute one or more programs; When the one or more programs are executed by the one or more processors, the silicon carbide MOSFET driving voltage control method according to any one of claims 1 to 8 is implemented.

18. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the silicon carbide MOSFET driving voltage control method as described in any one of claims 1 to 8 is implemented.

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