CN220122780U - Crosstalk suppression circuit and bridge circuit of SiC power device - Google Patents

Abstract

The utility model discloses a crosstalk suppression circuit and a bridge circuit of a SiC power device, and relates to the technical field of power electronics. The crosstalk suppression circuit comprises a switch module and a storage module; the first end of the switch module is electrically connected with the grid electrode of the SiC power device, and the second end of the switch module is electrically connected with the first end of the storage module; the second end of the storage module is electrically connected with the source electrode of the SiC power device; the switch module is used for being conducted under the condition that crosstalk occurs in the SiC power device; the storage module is used for adjusting the grid voltage of the SiC power device under the condition that the switch module is conducted, so that the grid voltage of the SiC power device is located in a preset range. According to the embodiment of the utility model, the crosstalk influence on the SiC power device can be quickly restrained, and the working reliability of a power electronic system is effectively ensured.

Description

Crosstalk suppression circuit and bridge circuit of SiC power device

Technical Field

The utility model belongs to the technical field of power electronics, and particularly relates to a crosstalk suppression circuit and a bridge circuit of a SiC power device.

Background

In the technical field of power electronics, silicon carbide (SiC) power devices, such as SiC metal-oxide semiconductor field effect transistors, have advantages of high breakdown voltage, fast switching speed, small on-resistance, high temperature resistance, good heat dissipation, and the like, and are widely used in high voltage, high temperature, high efficiency, high power density, and the like.

However, in a power electronic system in which an inverter of a main power driver of an automobile, a photovoltaic energy storage inverter, a switching power supply and other specific upper and lower bridge arms symmetrically work, the actual positive threshold voltage and the negative safety voltage of the SiC metal-oxide semiconductor field effect transistor are usually smaller, so that when the upper and lower bridge arms SiC metal-oxide semiconductor field effect transistor are switched on and off in the working process of the power electronic system, the bridge arm crosstalk problem is easy to cause the erroneous conduction or gate-source breakdown of the SiC metal-oxide semiconductor field effect transistor, further the switching loss is increased, the switching tube is damaged when serious, and the working stability of the power electronic system is affected.

In view of the above, how to quickly suppress the crosstalk influence of the SiC power device is a problem to be solved in the industry.

Disclosure of Invention

The crosstalk suppression circuit and the crosstalk suppression device for the SiC power device provided by the embodiment of the utility model can rapidly suppress the crosstalk influence of the SiC power device, and effectively ensure the working reliability of a power electronic system.

In a first aspect, an embodiment of the present utility model provides a crosstalk suppression circuit of a SiC power device, where the crosstalk suppression circuit includes a switch module and a memory module;

the first end of the switch module is electrically connected with the grid electrode of the SiC power device, and the second end of the switch module is electrically connected with the first end of the storage module;

the second end of the memory module is electrically connected with the source electrode of the SiC power device;

the switch module is used for conducting under the condition that crosstalk occurs in the SiC power device; the storage module is used for adjusting the grid voltage of the SiC power device under the condition that the switch module is conducted, so that the grid voltage of the SiC power device is located in a preset range.

In some possible implementations, the memory module includes a first capacitor;

the first pole of the first capacitor is electrically connected with the second end of the switch module, and the second pole of the first capacitor is electrically connected with the source electrode of the SiC power device.

In some possible implementations, the capacitance value of the first capacitance is greater than the capacitance value of the parasitic capacitance between the gate and the source of the SiC power device.

In some possible implementations, the switch module includes a first switch sub-module and a second switch sub-module;

the first end of the first switch sub-module is electrically connected with the grid electrode of the SiC power device, and the second end of the first switch sub-module is electrically connected with the first end of the storage module;

the second switch submodule is connected with the first switch submodule in parallel;

the first switch submodule is used for conducting under the condition that negative crosstalk occurs to the SiC power device; the second switch submodule is used for conducting under the condition that the SiC power device generates forward crosstalk.

In some possible embodiments, the second switching submodule is specifically configured to conduct when the SiC power device experiences forward crosstalk and a voltage difference between a gate and a source of the SiC power device is greater than a preset threshold.

In some possible implementations, the first switching submodule includes a first diode;

the cathode of the first diode is electrically connected with the grid electrode of the SiC power device, and the anode of the first diode is electrically connected with the first end of the memory module.

In some possible implementations, the second switch submodule includes a PNP transistor;

the emitter of the PNP type triode is electrically connected with the grid electrode of the SiC power device, and the collector of the PNP type triode is electrically connected with the first end of the storage module.

In some possible embodiments, the base of the PNP transistor is electrically connected to one end of the drive resistor.

In some possible embodiments, the crosstalk suppression circuit further comprises a protection module, a first end of the protection module being electrically connected to the gate of the SiC power device, and a second end of the protection module being electrically connected to the source of the SiC power device;

the protection module is used for preventing electrostatic breakdown of the SiC power device.

In a second aspect, an embodiment of the present utility model provides a bridge circuit, where the bridge circuit includes a SiC power device, and a crosstalk suppression circuit for the SiC power device provided in any one of the above embodiments of the present utility model.

Compared with the prior art, the embodiment of the utility model provides a crosstalk suppression circuit of a SiC power device, which is characterized in that a switch module and a storage module are connected in parallel and sequentially in series between the grid and the source of the SiC power device, the switch module is conducted under the condition that positive crosstalk or negative crosstalk occurs to the SiC power device, and the storage module is indirectly connected between the grid and the source of the SiC power device in parallel through the conducted switch module so as to adjust the grid potential of the SiC power device, so that the grid voltage of the SiC power device is in a preset range. According to the crosstalk suppression circuit of the SiC power device, by arranging the switch module and the storage module, the crosstalk influence on the SiC power device can be rapidly suppressed on the basis of not increasing the circuit complexity and the device cost as much as possible, so that the working reliability of a power electronic system is effectively ensured.

Drawings

In order to more clearly illustrate the technical solution of the embodiments of the present utility model, the drawings that are needed to be used in the embodiments of the present utility model will be briefly described, and it is possible for a person skilled in the art to obtain other drawings according to these drawings without inventive effort.

FIG. 1 is a schematic diagram of a bridge circuit according to an embodiment of the present utility model;

fig. 2 is a schematic structural diagram of a crosstalk suppression circuit of a SiC power device according to an embodiment of the present utility model;

fig. 3 is a schematic structural diagram of a crosstalk suppression circuit of a SiC power device according to another embodiment of the present utility model;

fig. 4 is a schematic structural diagram of a crosstalk suppression circuit of a SiC power device according to still another embodiment of the present utility model;

fig. 5 is a schematic structural diagram of a crosstalk suppression circuit of a SiC power device according to still another embodiment of the present utility model.

In the accompanying drawings:

1. a crosstalk suppression circuit of the SiC power device; 10. the switch module, 20, memory module; 30. a protection module; 11. a first switch sub-module; 12. a first switch sub-module.

Detailed Description

Features and exemplary embodiments of various aspects of the present utility model will be described in detail below, and in order to make the objects, technical solutions and advantages of the present utility model more apparent, the present utility model will be described in further detail below with reference to the accompanying drawings and the detailed embodiments. It should be understood that the particular embodiments described herein are meant to be illustrative of the utility model only and not limiting. It will be apparent to one skilled in the art that the present utility model may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the utility model by showing examples of the utility model.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

It should be noted that, without conflict, the embodiments of the present utility model and features of the embodiments may be combined with each other. The embodiments will be described in detail below with reference to the accompanying drawings.

As described in the background art section, at present, in a power electronic system in which a main power driver inverter, a photovoltaic energy storage inverter, a switching power supply and other specific upper and lower bridge arms of an automobile symmetrically work, it is important to ensure that one of the bridge arms is reliably turned off and not turned on by mistake when the other one of the bridge arms works. The actual positive threshold voltage and the negative safety voltage of the SiC power device, such as the SiC metal-oxide semiconductor field effect transistor, are usually smaller, so that when the upper and lower bridge arms SiC metal-oxide semiconductor field effect transistors are turned on and off in the working process of the power electronic system, the bridge arm crosstalk problem is often caused, and the erroneous conduction or gate-source breakdown of the SiC metal-oxide semiconductor field effect transistor is easily caused, so that the switching loss is increased, the switching tube is damaged in severe cases, and the working stability of the power electronic system is affected.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a bridge circuit according to an embodiment of the utility model. As shown in fig. 1, when the S1 at the upper bridge arm is turned on, the potential of the output terminal OUT in the bridge arm is changed, and a high displacement current du/dt is generated. In this way, under the action of the parasitic capacitance Cgs (usually very small) between the gate and the source of S2, the gate of S2 generates a crosstalk voltage, which causes a possibility of parasitic turn-on of S2, and the voltage spike exceeds the gate turn-on threshold of S2, which causes the bridge arm to be turned on directly, and thus causes the S2 to be damaged directly. When the upper bridge arm is turned off, the grid electrode of the S2 has a negative voltage spike, the drain electrode potential of the S2 is changed, negative displacement current is generated, and grid charges are extracted through a parasitic capacitance Cgd between the grid electrode and the drain electrode of the S2, so that the grid current of the S2 becomes smaller, the minimum negative voltage value required by the S2 is exceeded, and the grid reliability of the S2 is affected.

Aiming at the technical problems, in the prior art, the grid crosstalk signals of the SiC power device are generally clamped through the active clamping pins of the driving chips, however, because the clamping conditions of different driving chips are not consistent, the good clamping effect on the grid crosstalk signals of the SiC power device can not be ensured when the SiC power device uses different driving chips.

In view of the foregoing, in order to solve the above technical problems, embodiments of the present utility model provide a crosstalk suppression circuit and a bridge circuit of a SiC power device. The crosstalk suppression circuit of the SiC power device provided by the embodiment of the present utility model is first described below.

Fig. 2 is a schematic structural diagram of a crosstalk suppression circuit of a SiC power device according to an embodiment of the present utility model. As shown in fig. 2, the crosstalk suppression circuit 1 of the SiC power device includes a switch module 10 and a memory module 20.

A first end of the switch module 10 is electrically connected to the gate of the SiC power device and a second end of the switch module 10 is electrically connected to a first end of the memory module 20. A second terminal of the memory module 20 is electrically connected to the source of the SiC power device.

In specific operation, the switch module 10 may be turned on under the condition that crosstalk occurs in the SiC power device; the storage module 20 is used for adjusting the gate voltage of the SiC power device when the switch module 10 is turned on, so that the gate voltage of the SiC power device is within a preset range, that is, the SiC power device does not exceed the limit value of the gate when in use, thereby ensuring the reliable operation of the system during normal operation.

It should be noted that, the crosstalk generated by the SiC power device may be positive crosstalk or negative crosstalk, which is not limited in the present utility model. In this embodiment, the preset range may be specifically set according to the threshold voltage of the SiC power device and the minimum negative pressure required by the gate thereof.

Specifically, when the SiC power device is subjected to forward crosstalk, the storage module 20 may adjust the gate voltage of the SiC power device so that the gate voltage of the SiC power device does not exceed the forward threshold voltage thereof. When negative crosstalk occurs in the SiC power device, the storage module 20 may adjust the gate voltage of the SiC power device, so that the gate voltage of the SiC power device is not lower than the minimum negative voltage of the gate allowed by the SiC power device.

In this embodiment, by connecting the switch module and the storage module in parallel and sequentially in series between the gate and the source of the SiC power device, the switch module 10 is turned on, and the storage module 20 is indirectly connected in parallel between the gate and the source of the SiC power device through the turned-on switch module 10, so as to adjust the gate potential of the SiC power device, so that the gate voltage of the SiC power device is within a preset range. According to the crosstalk suppression circuit 1 of the SiC power device, provided by the embodiment of the utility model, by arranging the switch module 10 and the storage module 20, the crosstalk influence on the SiC power device can be rapidly suppressed on the basis of not increasing the circuit complexity and the device cost as much as possible, so that the working reliability of a power electronic system is effectively ensured.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a crosstalk suppression circuit of a SiC power device according to another embodiment of the present utility model. In some more specific embodiments, it is contemplated that in practice the crosstalk of SiC power devices is divided into positive crosstalk and negative crosstalk. Based on this, in order to more reasonably realize crosstalk suppression on the SiC power device on the premise of ensuring normal operation of the system, the above-mentioned switch module 10 may optionally include a first switch sub-module 11 and a second switch sub-module 12 as shown in fig. 3.

The first end of the first switch sub-module 11 may be electrically connected to the gate of the SiC power device, and the second end of the first switch sub-module 11 may be electrically connected to the first end of the memory module 20. The second switch sub-module 12 may be connected in parallel with the first switch sub-module 11.

In a specific operation, the first switch sub-module 11 may be used for conducting under the condition that negative crosstalk occurs in the SiC power device. The second switch sub-module 12 may be used to turn on in the event of forward crosstalk of the SiC power device. In practical applications, the first switch submodule 11 may be a device such as a diode, and the second switch submodule 12 may be a device such as a PNP transistor or a field effect transistor, which is not strictly limited in the present utility model.

In this way, by providing the first switch sub-module 11 and the second switch sub-module 12 that are different, crosstalk in different directions generated by the SiC power device can be controlled to be turned on respectively, so that positive crosstalk suppression or negative crosstalk suppression of the SiC power device can be more reasonably and accurately realized.

In some possible embodiments, optionally, considering that in a practical scenario, the SiC power device often needs to be turned on or off by a corresponding driving circuit, so in this embodiment, in order to ensure normal operation of the driving circuit of the SiC power device, the second switch submodule 12 may be specifically used to be turned on when forward crosstalk occurs in the SiC power device, and a voltage difference between a gate and a source of the SiC power device is greater than a preset threshold.

The preset threshold may be specifically set according to the switching characteristics of the second switch submodule 12, or may be flexibly set in combination with factors such as the gate threshold voltage of the SiC power device, which is not limited in the present utility model.

Referring to fig. 4, fig. 4 is a schematic structural diagram of a crosstalk suppression circuit of a SiC power device according to still another embodiment of the present utility model. In some possible embodiments, in order to further ensure the normal operation of the SiC power device while performing crosstalk suppression on the SiC power device, as shown in fig. 4, the crosstalk suppression circuit 1 further includes a protection module 30, where a first end of the protection module 30 is electrically connected to a gate of the SiC power device, and a second end of the protection module 30 is electrically connected to a source of the SiC power device;

the protection module 30 may be used to prevent electrostatic breakdown of SiC power devices. In particular, the protection module 30 may be a resistor or other element, which is not particularly limited in the present utility model.

Referring to fig. 5, fig. 5 is a schematic structural diagram of a crosstalk suppression circuit of a SiC power device according to still another embodiment of the present utility model. In some more specific embodiments, as shown in fig. 5, the memory module 20 may include a first capacitor C1. The SiC power device may specifically be a SiC metal-oxide semiconductor field effect transistor switching transistor S.

Specifically, a first pole of the first capacitor C1 may be electrically connected to the second terminal of the switch module 10, and a second pole of the first capacitor C1 may be electrically connected to the source of the SiC power device.

In some more specific embodiments, in order to better implement the adjustment of the gate potential of the SiC power device, so as to sufficiently ensure that the gate potential of the SiC power device does not exceed the limit potential allowed by the gate thereof, the capacitance value of the first capacitor C1 may be greater than the capacitance value of the parasitic capacitance between the gate and the source of the SiC power device.

For example, the capacitance value of the first capacitor C1 may be about 5 to 7 times of the parasitic capacitance between the gate and the source of the SiC power device, or the capacitance value of the first capacitor C1 may be larger, which is not particularly limited in the present utility model.

In this way, when crosstalk occurs in the SiC power device and the switching module 10 is turned on, the first capacitor C1 is actually connected in parallel with the parasitic capacitance between the gate and the source of the SiC power device.

Thus, when a higher displacement current is generated, the displacement current simultaneously charges the first capacitance C1 and the parasitic capacitance between the gate and the source of the SiC power device. The first capacitor C1 can play a main role in charge absorption on displacement current, so that parasitic capacitance between the grid electrode and the source electrode of the SiC power device can not rapidly change the grid electrode voltage of the SiC power device in a large range under the charging effect of the displacement current.

In this embodiment, due to the introduction of the first capacitor C1, it is finally ensured that the gate potential of the SiC power device only fluctuates in a small range and does not exceed the allowed voltage range, thereby effectively inhibiting parasitic conduction phenomenon of the gate of the SiC power device due to the influence of crosstalk.

In some possible embodiments, please continue to join fig. 5. Specifically, in order to quickly suppress negative crosstalk generated by the SiC power device, the first switch submodule 11 may specifically include a first diode D1.

In fig. 5, the cathode of the first diode D1 is electrically connected to the gate of the SiC power device, and the anode of the first diode D1 is electrically connected to the memory module 20, i.e., the first end of the first capacitor C1.

In this way, when the SiC power device generates negative crosstalk, that is, generates negative displacement current, the first diode D1 is turned on, and the first capacitor C1 is connected to the loop, so that the gate voltage of the SiC power device can be stabilized, and the SiC power device is ensured to fluctuate within a small range and cannot be lower than the gate negative voltage value allowed by the SiC power device.

In some possible embodiments, please continue to join fig. 5. In particular, in order to quickly, reasonably and at low cost suppress the forward crosstalk generated by the SiC power device, the second switch sub-module 12 may specifically include a PNP transistor.

The emitter of the PNP transistor may be electrically connected to the gate of the SiC power device, and the collector of the PNP transistor may be electrically connected to the memory module 20, i.e., the first end of the first capacitor C1.

When the SiC power device is in specific work, forward crosstalk occurs, and under the condition that the voltage difference between the grid electrode and the source electrode of the SiC power device is larger than the conduction threshold value of the PNP triode, the PNP triode is conducted, the first capacitor C1 is connected into a loop, and the grid electrode potential of the SiC power device is ensured not to exceed the specified grid electrode threshold voltage.

In some possible embodiments, considering the requirement of the SiC power device for the driving circuit, in order to determine the positional connection relationship between the crosstalk suppression circuit and the driving circuit of the SiC power device more reasonably, the base of the PNP transistor may be electrically connected to one end of the driving resistor Rg. Thus, normal driving and crosstalk suppression of the SiC power device are effectively ensured.

And, the protection module 30 may specifically be a resistor R1, where a first end of the resistor R1 is electrically connected to a gate of the SiC power device, and a second end of the resistor R1 is electrically connected to a source of the SiC power device, so as to prevent electrostatic breakdown of the SiC power device.

It will be appreciated that the foregoing is merely exemplary and is not intended to limit the crosstalk suppression circuitry of the SiC power devices protected by the present utility model.

The embodiment of the utility model also provides a bridge circuit, which comprises the SiC power device and the crosstalk suppression circuit of the SiC power device.

Specifically, the bridge circuit includes more than one SiC power device, and a crosstalk suppression circuit of the SiC power device provided in the foregoing embodiment may be disposed between the gate and the source of each SiC power device in the bridge circuit.

Taking an upper bridge arm and a lower bridge arm in a bridge circuit as an example, the crosstalk suppression circuit of the SiC power device may be arranged between the gate and the source of the SiC power device at the upper bridge arm position or between the gate and the source of the SiC power device at the lower bridge arm position. Alternatively, the crosstalk suppression circuits of the SiC power devices provided in the foregoing embodiments may be provided between the gate and source of the SiC power devices of the upper and lower bridge arms, which is not strictly limited by the present utility model.

The functional blocks shown in the above-described structural block diagrams may be implemented in hardware, software, firmware, or a combination thereof. When implemented in hardware, it may be, for example, an electronic circuit, an Application Specific Integrated Circuit (ASIC), suitable firmware, a plug-in, a function card, or the like. When implemented in software, the elements of the utility model are the programs or code segments used to perform the required tasks. The program or code segments may be stored in a machine readable medium or transmitted over transmission media or communication links by a data signal carried in a carrier wave. A "machine-readable medium" may include any medium that can store or transfer information. Examples of machine-readable media include electronic circuitry, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio Frequency (RF) links, and the like. The code segments may be downloaded via computer networks such as the internet, intranets, etc.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

The principles and embodiments of the present utility model have been described herein with reference to specific examples, the description of which is intended only to facilitate an understanding of the method of the present utility model and its core ideas. The foregoing is merely a preferred embodiment of the utility model, and it should be noted that, due to the limited text expressions, there is objectively no limit to the specific structure, and that, for a person skilled in the art, modifications, adaptations or variations may be made without departing from the principles of the present utility model, and the above technical features may be combined in any suitable manner; such modifications, variations and combinations, or direct application of the concepts and aspects of the utility model in other applications without modification, are contemplated as falling within the scope of the utility model.

Claims (10)

1. A crosstalk suppression circuit of a SiC power device, which is characterized by comprising a switch module and a storage module;

the first end of the switch module is electrically connected with the grid electrode of the SiC power device, and the second end of the switch module is electrically connected with the first end of the storage module;

the second end of the storage module is electrically connected with the source electrode of the SiC power device;

the switch module is used for being conducted under the condition that crosstalk occurs in the SiC power device; the storage module is used for adjusting the grid voltage of the SiC power device under the condition that the switch module is conducted, so that the grid voltage of the SiC power device is located in a preset range.

2. The crosstalk suppression circuit of claim 1, wherein the memory module comprises a first capacitance;

the first pole of the first capacitor is electrically connected with the second end of the switch module, and the second pole of the first capacitor is electrically connected with the source electrode of the SiC power device.

3. The crosstalk suppression circuit of claim 2, wherein a capacitance value of the first capacitance is greater than a capacitance value of a parasitic capacitance between a gate and a source of the SiC power device.

4. The crosstalk suppression circuit of claim 1, wherein the switch module comprises a first switch sub-module and a second switch sub-module;

the first end of the first switch sub-module is electrically connected with the grid electrode of the SiC power device, and the second end of the first switch sub-module is electrically connected with the first end of the storage module;

the second switch submodule is connected with the first switch submodule in parallel;

the first switch submodule is used for conducting under the condition that negative crosstalk occurs to the SiC power device; the second switch sub-module is used for conducting under the condition that the SiC power device generates forward crosstalk.

5. The crosstalk suppression circuit of claim 4, wherein the second switch sub-module is specifically configured to conduct when forward crosstalk occurs with the SiC power device and a voltage difference between a gate and a source of the SiC power device is greater than a preset threshold.

6. The crosstalk suppression circuit according to claim 4 or 5, characterized in that the first switching submodule comprises a first diode;

the cathode of the first diode is electrically connected with the grid electrode of the SiC power device, and the anode of the first diode is electrically connected with the first end of the storage module.

7. The crosstalk suppression circuit according to claim 4 or 5, characterized in that the second switch sub-module comprises a PNP transistor;

and the emitter of the PNP triode is electrically connected with the grid electrode of the SiC power device, and the collector of the PNP triode is electrically connected with the first end of the storage module.

8. The crosstalk suppression circuit of claim 7, wherein the base of the PNP transistor is electrically connected to one end of a drive resistor.

9. The crosstalk suppression circuit of claim 1, further comprising a protection module, a first end of the protection module being electrically connected to a gate of the SiC power device, a second end of the protection module being electrically connected to a source of the SiC power device;

the protection module is used for preventing electrostatic breakdown of the SiC power device.

10. A bridge circuit comprising a SiC power device, and a crosstalk suppression circuit for the SiC power device according to any one of claims 1 to 9.