Driving device of SiC-MOSFET device

Abstract

The embodiment of the invention provides a driving device of a SiC-MOSFET device, the driving device comprises a power supply conditioning circuit, at least one driving independent power supply module connected with the power supply conditioning circuit and a driver connected with the at least one driving independent power supply module, the power supply conditioning circuit is used for being connected with a preset direct current power supply, and the driving independent power supply module is used for being connected with the preset direct current power supply. The power supply output by the preset direct-current power supply is converted into a supply power supply required by each driving independent power supply module, and each driving independent power supply module is used for outputting a driving power supply required by the SiC-MOSFET device corresponding to the driving independent power supply module to the driver; and the driver is used for connecting at least one SiC-MOSFET device, outputting the driving power supply output by each driving independent power supply module to the SiC-MOSFET device corresponding to the driving independent power supply module, and controlling the on and off of each SiC-MOSFET device. The invention provides an applicable driving device for the SiC-MOSFET device.

Description

Technical Field

[0001] The present invention relates to semiconductor technology, and in particular to a driving device for a SiC-MOSFET device. Background Art

[0002] SiC-MOSFET devices are silicon carbide-metal oxide semiconductor field effect transistors, and are a type of power device. Currently, SiC-MOSFET devices are increasingly being used, but there is still no driver to drive SiC-MOSFET devices, so it is necessary to provide a driver for SiC-MOSFET devices. Summary of the invention

[0003] The embodiment of the present invention provides a driving device for a SiC-MOSFET device, thereby providing a suitable driving device for the SiC-MOSFET device.

[0004] An embodiment of the present invention provides a driving device for a SiC-MOSFET device, the driving device comprising: a power conditioning circuit, at least one independent driving power module connected to the power conditioning circuit, and a driver connected to the at least one independent driving power module, wherein:

[0005] The power conditioning circuit is used to connect to a preset DC power supply and convert the power output by the preset DC power supply into the power supply required for each driving independent power supply module;

[0006] The at least one independent driving power supply module corresponds to at least one SiC-MOSFET device one by one, and each independent driving power supply module is used to output the driving power required by the SiC-MOSFET device corresponding to the independent driving power supply module to the driver after receiving the supply power;

[0007] The driver is used to connect the at least one SiC-MOSFET device, output the driving power output by each driving independent power module to the SiC-MOSFET device corresponding to the driving independent power module, and control the conduction and shutdown of each SiC-MOSFET device.

[0008] In one embodiment, the driving device further comprises:

[0009] A control chip, used for sending a driving signal to a logic conditioning circuit;

[0010] The logic conditioning circuit is connected to the control chip and the driver respectively, and is used to receive a driving signal sent by the control chip, and send the driving signal to the driver, so that the driver controls the on and off of the SiC-MOSFET device.

[0011] In one embodiment, the driving device further comprises:

[0012] A pulse width modulation circuit, connected to the control chip, for outputting a pulse signal;

[0013] Correspondingly, the control chip is used to generate the driving signal according to the pulse signal output by the pulse width modulation circuit.

[0014] Furthermore, the driver is also used to: when detecting that any SiC-MOSFET device is in an abnormal state, send an error signal to the logic conditioning circuit; correspondingly, the logic conditioning circuit is also used to: when receiving the error signal, send the error signal to the control chip, so that the control chip controls the pulse width modulation circuit to stop outputting the pulse signal.

[0015] In one embodiment, the abnormal state includes an overcurrent state, a desaturation state, an undervoltage state or a short circuit state.

[0016] In one embodiment, the control chip and the logic conditioning circuit are connected via an optical fiber; the logic conditioning circuit comprises: an isolated optical fiber input module, a logic control module and an isolated optical fiber output module; wherein:

[0017] The isolated optical fiber input module is used to convert the driving signal in the form of an optical signal output by the control chip into a driving signal in the form of an electrical signal, and send the driving signal in the form of an electrical signal to the logic control module;

[0018] The logic control module is used to send a driving signal in the form of an electrical signal to the driver; the logic control module is also used to: receive an error signal in the form of an electrical signal sent by the driver, and send the error signal in the form of an electrical signal to the isolation optical fiber output module;

[0019] The isolation optical fiber output module is used to convert the error signal in the form of an electrical signal into an error signal in the form of an optical signal, and send the error signal in the form of an optical signal to the control chip.

[0020] In one embodiment, the driver is a capacitively isolated gate driver.

[0021] Furthermore, the driver includes a first protection circuit and a driving module; wherein:

[0022] The first protection circuit is used to determine that the SiC-MOSFET device is in a desaturation state when it is detected that the source-drain voltage of any SiC-MOSFET device reaches a preset value, and send a notification signal to the driving module;

[0023] The driving module is used to control the SiC-MOSFET device to turn off when receiving the notification signal.

[0024] Furthermore, the first protection circuit includes a current source, a voltage source, a first diode, a first resistor, a blanking capacitor and a comparator; wherein:

[0025] The current source is respectively connected to the non-inverting input terminal of the comparator, one end of the first resistor and one end of the blanking capacitor, the other end of the first resistor is connected to the anode of the first diode, the cathode of the first diode is connected to the drain of each SiC-MOSFET device, and the other end of the blanking capacitor is connected to the source of each SiC-MOSFET device; the source of each SiC-MOSFET device is grounded;

[0026] The voltage source is connected to the inverting input terminal of the comparator;

[0027] The output end of the comparator is connected to the driving module, and the comparator is used to send a notification signal to the driving module when the voltage value of the non-inverting input end is greater than the voltage value of the inverting input end;

[0028] Among them, the voltage value of the non-inverting input terminal is the sum of the drain-source voltage of the SiC-MOSFET device, the voltage drop value of the current source on the first diode, and the voltage drop value of the current source on the first resistor; the voltage value of the inverting input terminal is the voltage value output by the voltage source, and the voltage value is a preset desaturation voltage value.

[0029] Furthermore, the driver further includes a control module, which includes a second resistor, a third resistor and a second diode; wherein one end of the second resistor and the cathode of the second diode are connected to the drive signal output end of the drive module, and the other end of the second resistor is connected to the gate of each SiC-MOSFET device; one end of the third resistor is connected to the anode of the second diode, and the other end of the third resistor is connected to the gate of each SiC-MOSFET device;

[0030] Correspondingly, the driving module is used to: output a first voltage when the driving signal is at a high level, the first voltage is a positive voltage, and the first voltage makes the second diode in a cut-off state, and the first voltage makes the SiC-MOSFET device turned on; output a second voltage when the driving signal is at a low level, the second voltage is a negative voltage, and the second voltage makes the second diode in a conducting state, and the second voltage makes the SiC-MOSFET device turned off.

[0031] The driving device of the SiC-MOSFET device provided by the embodiment of the present invention has at least the following technical effects individually or in combination:

[0032] (1) The driving device includes a power conditioning circuit, at least one independent driving power module connected to the power conditioning circuit, and a driver connected to the at least one independent driving power module; the power conditioning circuit is used to connect a preset DC power supply and convert the power output by the preset DC power supply into the supply power required by each independent driving power module; each independent driving power module is used to output the driving power required by the SiC-MOSFET device corresponding to the independent driving power module to the driver after receiving the supply power; the driver is used to output the driving power output by each independent driving power module to the SiC-MOSFET device corresponding to the independent driving power module, and control the conduction and shutdown of each SiC-MOSFET device. It can be seen that the embodiment of the present invention provides a suitable driving device for SiC-MOSFET devices, wherein an independent driving power module is configured for each SiC-MOSFET device, so as to provide a corresponding driving power for each SiC-MOSFET device, and each independent driving power module can obtain the supply power required by each SiC-MOSFET device from the power conditioning circuit, so that the source branches of the driving power of each SiC-MOSFET device are independent and isolated from each other, and will not affect each other, which can reduce the mutual interference between each SiC-MOSFET device to a certain extent.

[0033] (2) In one embodiment, the driver is a capacitive isolation gate driver. Since the capacitive isolation gate driver itself has a high common-mode transient suppression capability, it is very suitable for driving high-speed SiC MOSFET devices. Moreover, since the characteristic of SiC MOSFET devices is that the switching speed is very fast, SiC MOSFET devices are susceptible to various interferences, which may affect the switching control of SiC MOSFET devices. The capacitive isolation gate driver integrates multiple protection modules, which can perform corresponding operations in time when the SiC MOSFET device is abnormal due to interference or other reasons, thereby reducing the impact of various interferences on the switching control of the SiC MOSFET device.

[0034] (3) In one embodiment, the driver includes a first protection circuit, which is used to determine that the SiC-MOSFET device is in a desaturation state when the source-drain voltage of any SiC-MOSFET device reaches a preset value, and send a notification signal to the driving module; the driving module is used to control the SiC-MOSFET device to turn off when receiving the notification signal. It can be seen that the desaturation protection function can be realized in the driver through the first protection circuit and the driving module.

[0035] (4) In one embodiment, the first protection circuit includes a current source, a voltage source, a first diode, a first resistor, a blanking capacitor and a comparator. When the drain-source voltage of the SiC-MOSFET device reaches the above-mentioned preset value, the sum of the drain-source voltage of the SiC-MOSFET device, the voltage drop value of the current source on the first diode and the voltage drop value of the current source on the first resistor will be greater than the voltage provided by the voltage source. At this time, the comparator will output a notification signal to the drive module, and then the drive module controls the SiC-MOSFET device to turn off. It can be seen that a specific structure of the first protection circuit is provided here. In this specific structure, the drain-source voltage of the SiC-MOSFET device can be monitored in real time. Once the drain-source voltage of the SiC-MOSFET device reaches the preset value, the comparator will notify the drive module, and then turn off the SiC-MOSFET device, and perform desaturation protection operation in time.

[0036] (5) In one embodiment, the driver further includes a control module, and the control module includes a second resistor, a third resistor, and a second diode. When the SiC-MOSFET device needs to be turned on, the driver module outputs a first voltage, which is a positive voltage. The first voltage is higher than the gate voltage of the SiC-MOSFET device, and can turn on the SiC-MOSFET device. Moreover, the first voltage can make the second diode in a cut-off state. At this time, the branch where the second resistor in the control module is located is turned on, while the branch where the third resistor is located has no current passing through. When the SiC-MOSFET device needs to be turned off, the driver module outputs a second voltage, which is a negative voltage. The second voltage is less than the gate voltage of the SiC-MOSFET device, and thus turns off the SiC-MOSFET device. Moreover, the second voltage turns on the second diode, so the branch where the third resistor is located also has current passing through it. Of course, at this time, the branch where the second resistor is located also has current passing through it. At this time, the total resistance of the two parallel branches is less than the resistance value of the second resistor. It can be seen that when the SiC-MOSFET device needs to be turned off, a relatively small gate resistance can reduce the switching loss. For circuits with a large number of SiC-MOSFET devices, reducing the switching loss can greatly reduce the overall loss of the driving device. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 Schematic diagram of connection between a driving device of a SiC-MOSFET device and a SiC-MOSFET device in one embodiment of the present invention;

[0039] Figure 2 is a schematic diagram of connection between a driving device of a SiC-MOSFET device and a SiC-MOSFET device in another embodiment of the present invention;

[0040] Figure 3 is a schematic diagram of the structure of a logic conditioning circuit in one embodiment of the present invention;

[0041] Figure 4 is a circuit diagram of a driver in one embodiment of the present invention.

[0042] Reference numerals:

[0043] DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions 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, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0045] An embodiment of the present invention provides a driving device for a SiC-MOSFET device.

[0046] See also Figure 1 The driving device comprises: a power conditioning circuit 110, at least one independent driving power module 120 connected to the power conditioning circuit 110, and a driver 130 connected to the at least one independent driving power module 120, wherein:

[0047] The power conditioning circuit 110 is used to connect to a preset DC power source and convert the power output by the preset DC power source into the power supply required by each driving independent power module 120;

[0048] The at least one independent driving power supply module 120 corresponds to at least one SiC-MOSFET device 200 one by one, and each independent driving power supply module 120 is used to output the driving power required by the SiC-MOSFET device 200 corresponding to the independent driving power supply module 120 to the driver 130 after receiving the supply power;

[0049] The driver 130 is used to connect the at least one SiC-MOSFET device 200, supply the driving power output by each driving independent power module 120 to the SiC-MOSFET device 200 corresponding to the driving independent power module, and control the conduction and shutdown of each SiC-MOSFET device 200.

[0050] Among them, SiC-MOSFET devices are silicon carbide-metal oxide semiconductor field effect transistors, which are power devices.

[0051] The function of the power conditioning circuit is to convert a DC source outputted by a preset DC power supply into at least one supply power supply, and each supply power supply can be the same or different, depending on the requirements of each independent driving power supply module. Each supply power supply is independent of each other and supplies power to the corresponding independent driving power supply module.

[0052] Each independent driving power supply module works under the supply power and outputs the corresponding driving power to the driver. The driving power output by each independent driving power supply module can be the same or different, depending on the requirements of each SiC-MOSFET device. Each independent driving power supply module is independent and isolated from each other and will not affect each other, providing driving power for each SiC-MOSFET device.

[0053] It is understandable that, in order to achieve overall control of each independent driving power supply module, each driving power supply output by each independent driving power supply module is first input into the driver, and then the driver supplies each driving power supply to each SiC-MOSFET device to provide driving power for each SiC-MOSFET device. For example, if in a scenario, one of the SiC-MOSFET devices has a problem, but the remaining SiC-MOSFET devices can still work normally, then the driver does not need to provide driving power for the SiC-MOSFET device with the problem.

[0054] It is understandable that only when the SiC-MOSFET device is provided with driving power will it enter various states, such as off, on, etc. The state control of the SiC-MOSFET device is implemented by the driver.

[0055] It can be seen that the main function of the driver is to supply the driving power output by the driving independent power module to the corresponding SiC-MOSFET device, and to control the on or off state of each SiC-MOSFET device.

[0056] It is understandable that when the SiC-MOSFET device is turned off, it does not mean that the SiC-MOSFET device stops working. When the SiC-MOSFET device is in the on or off state, it will cause the subsequent modules connected to the SiC-MOSFET device to be in different states, thereby achieving different functions.

[0057] In one embodiment, see Figure 2 The driving device provided in the embodiment of the present invention may further include:

[0058] The control chip 150 is used to send a driving signal to the logic conditioning circuit 140;

[0059] The logic conditioning circuit 140 is connected to the control chip 150 and the driver 130 respectively, and is used to send the driving signal to the driver 130 when receiving the driving signal sent by the control chip 150, so that the driver 130 controls the conduction and shutdown of the SiC-MOSFET device 200.

[0060] That is to say, the driving device includes a power conditioning circuit, at least one independent driving power supply module, a driver, a control chip, and a logic conditioning circuit.

[0061] Among them, the function of the control chip is to send a driving signal to the logic conditioning circuit, and the function of the logic conditioning circuit is to send the driving signal to the driver, so that the driver controls the conduction and shutdown of each SiC-MOSFET device under the action of the driving signal.

[0062] It can be seen that the control chip here sends a driving signal to the driver through a logic conditioning circuit, so that the staff can control it through the control chip to decide when to start sending the driving signal and when to stop sending the driving signal. That is, by setting up a control chip, the staff's requirements for sending driving signals on demand can be met.

[0063] For further information, see Figure 2 The driving device provided in the embodiment of the present invention may further include:

[0064] A pulse width modulation circuit 160, connected to the control chip 150, for outputting a pulse signal;

[0065] Correspondingly, the control chip 150 is used to generate the driving signal according to the pulse signal output by the pulse width modulation circuit 160 .

[0066] That is to say, the control chip is connected to a pulse width modulation circuit, i.e., a PWM circuit, which can output a pulse signal to the control chip, and the control chip can generate a drive signal according to the pulse signal. For example, the high level of the pulse signal is 1, and the low level is 0, and the control chip converts the high level in the pulse signal into a positive voltage, and the control chip converts the low level in the pulse signal into a negative voltage. Among them, the positive voltage can make the corresponding SiC-MOSFET device enter the on state, and the negative voltage can make the corresponding SiC-MOSFET device enter the off state. The positive voltage and the negative voltage form a drive signal in the form of a rectangular wave.

[0067] For example, in one scenario, the staff controls the control chip so that the control chip starts the pulse width modulation circuit, so that the pulse width modulation circuit sends a pulse signal. The staff can also control the control chip so that the control chip stops the pulse width modulation circuit, so that the pulse width modulation circuit stops sending a pulse signal.

[0068] Of course, in addition to the external control method of the staff, when the SiC-MOSFET device itself is abnormal, it will automatically control the pulse width modulation circuit to stop outputting the pulse signal. In one embodiment, the driver can also be used to: send an error signal to the logic conditioning circuit when any SiC-MOSFET device is detected to be in an abnormal state; correspondingly, the logic conditioning circuit is also used to: when receiving the error signal, send the error signal to the control chip, so that the control chip controls the pulse width modulation circuit to stop outputting the pulse signal.

[0069] That is to say, when the driver detects that any SiC-MOSFET device is abnormal, it will send an error signal to the logic conditioning circuit. When the logic conditioning circuit receives the error signal, it will send the error signal to the control chip. When the control chip receives the error signal, it will control the pulse width modulation circuit to stop outputting the pulse signal, thereby causing each SiC-MOSFET device to stop working.

[0070] The abnormal state may include an overcurrent state, a desaturation state, an undervoltage state or a short circuit state.

[0071] It can be seen that when any SiC-MOSFET device becomes abnormal, each SiC-MOSFET device will be controlled to stop working through the driver, logic conditioning circuit, control chip, and pulse width modulation circuit, thereby preventing the abnormal SiC-MOSFET device from affecting the functions of subsequent modules connected to the SiC-MOSFET device.

[0072] In one embodiment, the control chip and the logic conditioning circuit can be connected via an optical fiber; correspondingly, see Figure 3 , the logic conditioning circuit may include: an isolated optical fiber input module 142, a logic control module 141 and an isolated optical fiber output module 143; wherein:

[0073] The isolated optical fiber input module 142 is used to convert the driving signal in the form of an optical signal output by the control chip into a driving signal in the form of an electrical signal, and send the driving signal in the form of an electrical signal to the logic control module;

[0074] The logic control module 141 is used to send a driving signal in the form of an electrical signal to the driver; the logic control module is also used to: receive an error signal in the form of an electrical signal sent by the driver, and send the error signal in the form of an electrical signal to the isolation optical fiber output module;

[0075] The isolated optical fiber output module 143 is used to convert the error signal in the form of an electrical signal into an error signal in the form of an optical signal, and send the error signal in the form of an optical signal to the control chip.

[0076] That is to say, the logic conditioning circuit includes an isolated fiber input module, a logic control module, and an isolated fiber output module. The function of the isolated fiber input module is to convert the driving signal sent by the control chip from an optical signal to an electrical signal. The function of the isolated fiber output module is to convert the error signal sent by the driver from an electrical signal to an optical signal. It can be seen that the isolated fiber input module and the isolated fiber output module isolate the optical signal and the electrical signal and realize the conversion between the two.

[0077] Among them, the number of isolated fiber input modules can be one or more, and one of the isolated fiber input modules in an idle state is used each time; the number of isolated fiber output modules can also be set to one or more, and one of the isolated fiber output modules in an idle state is used each time.

[0078] In one embodiment, the driver in the embodiment of the present invention may be a capacitive isolation type gate driver.

[0079] It is understandable that as the operating frequency of power switching devices continues to increase, from 10kHz for Si IGBT to 100kHz for SiC MOSFET devices, better requirements are placed on the drivers of power switching devices. Since the characteristic of SiCMOSFET devices is that the switching speed is very fast, if a driver similar to an optocoupler is used, there is an insurmountable problem that the common-mode transient suppression capability, i.e., the CMTI value, is not large enough, which is very dangerous for high-speed SiC MOSFET devices. Therefore, the driver in the embodiment of the present invention adopts a capacitive isolation gate driver. The capacitive isolation gate driver itself has a high common-mode transient suppression capability and is very suitable for driving high-speed SiC MOSFET devices.

[0080] Moreover, due to the fast switching speed of SiC MOSFET devices, SiC MOSFET devices are susceptible to various interferences, which may affect the switching control of SiC MOSFET devices. The protection function inside the capacitor-isolated gate driver can perform corresponding operations in time when the SiC MOSFET device is abnormal, thereby reducing the impact of various electromagnetic interferences on the switching control of SiC MOSFET devices.

[0081] It is understandable that the capacitor-isolated gate driver integrates undervoltage protection, desaturation protection, short-circuit protection, overcurrent protection, gate active tracking protection, and source Miller clamping protection. These protection functions can ensure that corresponding protection operations are performed when an abnormality occurs in the SiC MOSFET device.

[0082] In actual scenarios, the appropriate capacitive isolation gate driver can be selected based on some indicators, such as the required driving capability, the switching frequency and transmission delay required in actual applications, the ability to suppress common-mode transients, etc. Based on these indicators, the appropriate capacitive isolation gate driver can be selected from various types of capacitive isolation gate drivers.

[0083] In one embodiment, see Figure 4 , the driver may include a first protection circuit 131 and a driving module 132; wherein:

[0084] The first protection circuit 131 is used to determine that the SiC-MOSFET device 200 is in a desaturated state when it is detected that the source-drain voltage of any SiC-MOSFET device 200 reaches a preset value, and send a notification signal to the driving module 132;

[0085] The driving module 132 is used to control the SiC-MOSFET device 200 to be turned off when receiving the notification signal.

[0086] That is to say, the driver can realize the desaturation protection function through the first protection circuit and the driving module. The first protection circuit connects the source and drain of each SiC-MOSFET device to detect the source-drain voltage of the SiC-MOSFET device. When the drain-source voltage of any SiC-MOSFET device is greater than the above preset value, it can be considered that the SiC-MOSFET device is in a desaturation state. At this time, the driving module is informed through a notification signal to perform desaturation protection.

[0087] For example, for a 300A / 1700V SiC-MOSFET device, in its output characteristic curve, the horizontal axis is Vds voltage and the vertical axis is Ids current. When the source-drain voltage is around 10V, the output current of the SiC-MOSFET device reaches about 280A and is clamped. When the source-drain voltage is around 15V, the output current can reach about 700A. At this time, it is considered to enter the desaturation state, and the SiC MOSFET device needs to be turned off.

[0088] The first protection circuit can be implemented in a variety of structural forms, see Figure 4 , an optional structure is provided below:

[0089] The first protection circuit 131 may include a current source A, a voltage source V, a first diode D1, a first resistor R1, a blanking capacitor C1 and a comparator E1; wherein:

[0090] The current source A is respectively connected to the non-inverting input terminal of the comparator E1, one end of the first resistor R1 and one end of the blanking capacitor C1, the other end of the first resistor R1 is connected to the positive electrode of the first diode D1, the negative electrode of the first diode D1 is connected to the drain D of each SiC-MOSFET device, and the other end of the blanking capacitor C1 is connected to the source S of each SiC-MOSFET device; the source S of each SiC-MOSFET device is grounded;

[0091] The voltage source V is connected to the inverting input terminal of the comparator E1;

[0092] The output end of the comparator E1 is connected to the driving module 132, and the comparator E1 is used to send a notification signal to the driving module 132 when the voltage value of the non-inverting input end is greater than the voltage value of the inverting input end;

[0093] Among them, the voltage value of the non-inverting input terminal is the sum of the drain-source voltage of the SiC-MOSFET device, the voltage drop value of the current source A on the first diode D1, and the voltage drop value of the current source A on the first resistor R1; the voltage value of the inverting input terminal is the voltage value output by the voltage source V, and the voltage value is a preset desaturation voltage value.

[0094] The comparator E1 sends a notification signal to the desaturation protection terminal DESAT of the driving module 132 .

[0095] That is to say, when the drain-source voltage of the SiC-MOSFET device reaches the above-mentioned preset value, the sum of the drain-source voltage of the SiC-MOSFET device, the voltage drop value of the current source on the first diode, and the voltage drop value of the current source on the first resistor will be greater than the voltage provided by the voltage source. At this time, the comparator will output a notification signal to the drive module, and then the drive module controls the SiC-MOSFET device to turn off.

[0096] Among them, the function of the current source is to output a constant current. The constant current generates a voltage drop value after passing through the resistor, and generates another voltage drop value after passing through the first diode. The sum of the two voltage drop values ​​and the drain-source voltage of the SiC-MOSFET device is used as the input voltage of the non-inverting input terminal of the comparator.

[0097] The voltage source is used to provide a reference voltage, which is a preset desaturation voltage value. The reference voltage output by the voltage source is used as the input voltage of the inverting input terminal.

[0098] The comparator compares the input voltage of the non-inverting input terminal with the input voltage of the inverting input terminal. If the input voltage of the non-inverting input terminal is greater than the input voltage of the inverting input terminal, a notification signal is output to the driving module to perform desaturation protection.

[0099] It can be seen that the desaturation protection function can be achieved through the above method.

[0100] Of course, the driving module can also generate an error signal and send it to the logic conditioning circuit, and then control the pulse width modulation circuit to stop outputting the pulse signal through the control chip.

[0101] It is understandable that, for other protection functions, other protection circuits may be used to implement them one by one, which will not be described one by one here.

[0102] For further information, see Figure 4, the driver may further include a control module 133, the control module 133 includes a second resistor R2, a third resistor R3 and a second diode D2; wherein one end of the second resistor R2 and the cathode of the second diode D2 are connected to the drive signal output end of the drive module, and the other end of the second resistor R2 is connected to the gate of each SiC-MOSFET device; one end of the third resistor R3 is connected to the anode of the second diode D2, and the other end of the third resistor R3 is connected to the gate of each SiC-MOSFET device;

[0103] Correspondingly, the driving module is used to: output a first voltage when the driving signal is at a high level, the first voltage is a positive voltage, and the first voltage makes the second diode D2 in a cut-off state, and the first voltage makes the SiC-MOSFET device turned on; output a second voltage when the driving signal is at a low level, the second voltage is a negative voltage, and the second voltage makes the second diode D2 in a conducting state, and the second voltage makes the SiC-MOSFET device turned off.

[0104] It can be seen that the control module is arranged between the driving module and the gate of the SiC-MOSFET device.

[0105] One end of the second resistor R2 and the cathode of the second diode D2 are connected to the driving signal output terminal OUT of the driving module. The driving module outputs the first voltage and the second voltage through the driving signal output terminal OUT.

[0106] When the SiC-MOSFET device needs to be turned on, the driving module will output a first voltage, which is a positive voltage, such as 15V. The first voltage is higher than the gate voltage of the SiC-MOSFET device, and can turn on the SiC-MOSFET device. In addition, the first voltage can turn the second diode off, and the branch where the second resistor in the control module is located is turned on, while the branch where the third resistor is located has no current flowing through it.

[0107] When the SiC-MOSFET device needs to be turned off, the driver module will output a second voltage, which is a negative voltage, for example, -8V. The second voltage is less than the gate voltage of the SiC-MOSFET device, so the SiC-MOSFET device is turned off. Moreover, the second voltage turns on the second diode, so the branch where the third resistor is located also has current flowing through it. Of course, the branch where the second resistor is located also has current flowing through it. At this time, the total resistance of the two parallel branches is less than the resistance value of the second resistor.

[0108] Here, a control module is set between the driving module and the gate of the SiC-MOSFET device. When the SiC-MOSFET device needs to be turned off, the gate resistance is relatively small to reduce the switching loss. For circuits with a large number of SiC-MOSFET devices, reducing the switching loss can greatly reduce the overall loss of the driving device.

[0109] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0110] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solution of the present invention should be included in the scope of protection of the present invention.

Claims

1. A driving device for a SiC-MOSFET device, characterized in that: The driving device comprises: a power conditioning circuit, at least one independent driving power supply module connected to the power conditioning circuit, and a driver connected to the at least one independent driving power supply module, wherein: The power conditioning circuit is used to connect to a preset DC power supply and convert the power output by the preset DC power supply into the power supply required for each driving independent power supply module; The at least one independent driving power supply module corresponds to at least one SiC-MOSFET device one by one, and each independent driving power supply module is used to output the driving power required by the SiC-MOSFET device corresponding to the independent driving power supply module to the driver after receiving the supply power; The driver is used to connect the at least one SiC-MOSFET device, output the driving power output by each driving independent power module to the SiC-MOSFET device corresponding to the driving independent power module, and control the conduction and shutdown of each SiC-MOSFET device.

2. The device according to claim 1, characterized in that Also includes: A control chip, used for sending a driving signal to a logic conditioning circuit; The logic conditioning circuit is connected to the control chip and the driver respectively, and is used to receive a driving signal sent by the control chip, and send the driving signal to the driver, so that the driver controls the on and off of the SiC-MOSFET device.

3. The device according to claim 2, characterized in that Also includes: A pulse width modulation circuit, connected to the control chip, for outputting a pulse signal; Correspondingly, the control chip is used to generate the driving signal according to the pulse signal output by the pulse width modulation circuit.

4. The device according to claim 3, characterized in that The driver is also used to: send an error signal to the logic conditioning circuit when detecting that any one of the SiC-MOSFET devices is in an abnormal state; Correspondingly, the logic conditioning circuit is also used to: when receiving the error signal, send the error signal to the control chip, so that the control chip controls the pulse width modulation circuit to stop outputting the pulse signal.

5. The device according to claim 4, characterized in that The abnormal state includes an overcurrent state, a desaturation state, an undervoltage state or a short circuit state.

6. The device according to claim 4, characterized in that The control chip and the logic conditioning circuit are connected via an optical fiber; The logic conditioning circuit comprises: an isolated optical fiber input module, a logic control module and an isolated optical fiber output module; wherein: The isolated optical fiber input module is used to convert the driving signal in the form of an optical signal output by the control chip into a driving signal in the form of an electrical signal, and send the driving signal in the form of an electrical signal to the logic control module; The logic control module is used to send a driving signal in the form of an electrical signal to the driver; the logic control module is also used to: receive an error signal in the form of an electrical signal sent by the driver, and send the error signal in the form of an electrical signal to the isolation optical fiber output module; The isolation optical fiber output module is used to convert the error signal in the form of an electrical signal into an error signal in the form of an optical signal, and send the error signal in the form of an optical signal to the control chip.

7. The device according to claim 1, characterized in that The driver is a capacitive isolation type gate driver.

8. The device according to claim 7, characterized in that The driver includes a first protection circuit and a driving module; wherein: The first protection circuit is used to determine that the SiC-MOSFET device is in a desaturation state when it is detected that the source-drain voltage of any SiC-MOSFET device reaches a preset value, and send a notification signal to the driving module; The driving module is used to control the SiC-MOSFET device to turn off when receiving the notification signal.

9. The device according to claim 8, characterized in that The first protection circuit includes a current source, a voltage source, a first diode, a first resistor, a blanking capacitor and a comparator; wherein: The current source is respectively connected to the non-inverting input terminal of the comparator, one end of the first resistor and one end of the blanking capacitor, the other end of the first resistor is connected to the anode of the first diode, the cathode of the first diode is connected to the drain of each SiC-MOSFET device, and the other end of the blanking capacitor is connected to the source of each SiC-MOSFET device; the source of each SiC-MOSFET device is grounded; The voltage source is connected to the inverting input terminal of the comparator; The output end of the comparator is connected to the driving module, and the comparator is used to send a notification signal to the driving module when the voltage value of the non-inverting input end is greater than the voltage value of the inverting input end; Among them, the voltage value of the non-inverting input terminal is the sum of the drain-source voltage of the SiC-MOSFET device, the voltage drop value of the current source on the first diode, and the voltage drop value of the current source on the first resistor; the voltage value of the inverting input terminal is the voltage value output by the voltage source, and the voltage value is a preset desaturation voltage value.

10. The device according to claim 8, characterized in that The driver also includes a control module, which includes a second resistor, a third resistor and a second diode; wherein one end of the second resistor and the cathode of the second diode are connected to the drive signal output end of the drive module, and the other end of the second resistor is connected to the gate of each SiC-MOSFET device; one end of the third resistor is connected to the anode of the second diode, and the other end of the third resistor is connected to the gate of each SiC-MOSFET device; Correspondingly, the driving module is used to: output a first voltage when the driving signal is at a high level, the first voltage is a positive voltage, and the first voltage makes the second diode in a cut-off state, and the first voltage makes the SiC-MOSFET device turned on; output a second voltage when the driving signal is at a low level, the second voltage is a negative voltage, and the second voltage makes the second diode in a conducting state, and the second voltage makes the SiC-MOSFET device turned off.

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