Driving circuit for insulated gate bipolar transistor, electronic device and vehicle

Abstract

A driving circuit for an insulated gate bipolar transistor (IGBT), an electronic apparatus, and a vehicle are provided. The driving circuit comprises a driving control circuit which is used for outputting a driving voltage signal at a first output end to control the switching state of an IGBT, and stopping outputting the driving voltage signal or setting the driving voltage signal as an invalid level when a short circuit fault at the IGBT is detected; a gate voltage control circuit for providing a gate voltage at a gate of the IGBT based on the driving voltage signal, and implementing discharge of the gate voltage in the case of a short-circuit fault at the IGBT; and a charge / discharge auxiliary circuit connected to the gate voltage control circuit for slowing down the discharge speed of the gate voltage in the case of a short-circuit fault at the IGBT.

Description

Technical Field

[0001] The present application relates to the field of circuits, and more specifically, to a driving circuit for an insulated gate bipolar transistor (IGBT) with a short-circuit protection function. Background Art

[0002] Insulated-gate bipolar transistors (IGBTs) are widely used in various electronic circuits to implement switching functions. A typical application is as a bridge switch in an inverter. Figure 1 The figure shows a common main circuit topology of a three-phase inverter, in which the upper and lower bridge arms corresponding to each phase output are each provided with an IGBT.

[0003] When an IGBT short circuit occurs (such as Figure 1 As shown in the left figure), the short-circuit current will rise to more than 4 times the rated current, and the corresponding voltage difference VCE between the collector and emitter will also be higher than 9V when the IGBT is short-circuited and turned on. Currently, the IGBT drive circuit is generally equipped with a protection function, so that when an abnormal VCE of the IGBT is detected, the IGBT will be turned off to cut off the short-circuit loop (such as Figure 1 However, when the cut-off speed is too fast, the current change rate (expressed as di / dt) will be large, and there will be stray inductance in the circuit, which will cause a high spike voltage between the collector and emitter, which may cause damage to the IGBT.

[0004] Therefore, a solution is needed to avoid a very high spike voltage between the collector and emitter of the IGBT when a short circuit fault occurs in the IGBT and the IGBT is turned off. Summary of the Invention

[0005] According to one aspect of the present application, a drive circuit for an insulated gate bipolar transistor (IGBT) is provided, comprising: a drive control circuit for outputting a drive voltage signal at a first output terminal to control the switching state of the IGBT, and when a short-circuit fault is detected at the IGBT, stopping outputting the drive voltage signal or setting the drive voltage signal to an invalid level; a gate voltage control circuit for providing a gate voltage at the gate of the IGBT based on the drive voltage signal, and discharging the gate voltage in the event of a short-circuit fault at the IGBT; and a charge and discharge auxiliary circuit connected to the gate voltage control circuit, for slowing down the discharge speed of the gate voltage in the event of a short-circuit fault at the IGBT.

[0006] According to another aspect of the present application, a drive circuit for an insulated gate bipolar transistor (IGBT) is provided, comprising: a drive control circuit for outputting a drive voltage signal at a first output terminal to control the switching state of the IGBT; a gate voltage control circuit for providing a gate voltage at the gate based on the drive voltage signal, and discharging the gate voltage in the event of a short-circuit fault at the IGBT; and a desaturation protection circuit, comprising: a capacitor connected between a second output terminal of the drive control circuit and the emitter of the IGBT; a first current source and a second current source for charging the capacitor; and a series branch of a resistor and a diode, the series branch being connected between the capacitor and the collector of the IGBT, wherein when the voltage value of the voltage signal at the second output terminal exceeds a threshold value, the drive control circuit determines the desaturation state of the IGBT, wherein the desaturation state is at least associated with the short-circuit fault.

[0007] It can be seen that in the embodiments of the present application, in order to reduce the voltage spike during the short-circuit protection process, improvements can be made in at least one of the desaturation detection stage and the short-circuit protection stage. For example, in the desaturation detection stage, by adding a current source, short-circuit protection can be performed as quickly as possible under a Class I short-circuit fault to increase safety, and by increasing the capacitance value under a Class II short-circuit fault to avoid large current while still meeting the action time requirements of a Class I short-circuit fault; in the short-circuit protection stage, by adding a charging path, the discharge speed of the gate voltage can be slowed down, thereby reducing the voltage spike between the collector and emitter of the IGBT. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The accompanying drawings illustrate various embodiments of various aspects of the present application, and together with the description, they serve to explain the principles of the present application. Those skilled in the art will appreciate that the specific embodiments shown in the drawings are merely exemplary and are not intended to limit the scope of the present application. In the drawings:

[0009] Figure 1 A main circuit topology of a three-phase inverter is shown;

[0010] Figures 2A-2B A schematic diagram of a drive circuit for an insulated gate bipolar transistor (IGBT) according to an embodiment of the present application is shown;

[0011] Figure 3 Shown Figures 2A-2B Further structure of the driving circuit shown;

[0012] Figure 4 A circuit diagram of a desaturation detection circuit and a desaturation protection circuit is shown;

[0013] Figure 5 shows a circuit diagram of a desaturation protection circuit according to an embodiment of the present application; DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0015] As mentioned above, when the IGBT is turned off, a very high spike voltage may occur between the collector and emitter, which may damage the IGBT. Therefore, a solution is needed to avoid the very high spike voltage between the collector and emitter of the IGBT when a short circuit fault occurs and the IGBT is turned off.

[0016] Two-level turn-off and soft turn-off are usually used. Both methods are designed to slow down the turn-off speed of the IGBT.

[0017] In the two-level turn-off method, when the IGBT is turned off, the gate voltage of the IGBT will drop from the turn-on voltage (usually 15V) to the first turn-off voltage of the two levels (U_tlto, for example, 10V) and maintain it for 1-2μs. Then the gate voltage of the IGBT will continue to drop from U_tlto to the turn-off voltage (for example, -5V). The two-level turn-off time can be modified by an additional capacitor, that is, the duration of holding at each level can be configured by the capacitor, and the voltage amplitude of the two-level turn-off can be adjusted by an additional Zener diode.

[0018] In the soft-off mode, when the IGBT is turned off, a resistor is connected in series in the loop between the gate and the ground to form a high-resistance loop, so that the discharge speed of the parasitic capacitance at the IGBT gate can be slowed down.

[0019] However, the above method is still insufficient in some cases, especially when the short-circuit current is particularly large, so an improved method is needed.

[0020] Figures 2A-2B A schematic diagram of a driving circuit for an insulated gate bipolar transistor (IGBT) according to an embodiment of the present application is shown.

[0021] like Figure 2A As shown, the driving circuit 100 includes a driving control circuit 110 , a gate voltage control circuit 120 and a charge and discharge auxiliary circuit 130 .

[0022] The drive control circuit 110 is configured to output a drive voltage signal at a first output terminal to control the switching state of the IGBT, and when a short circuit fault is detected at the IGBT, stop outputting the drive voltage signal or set the drive voltage signal to an invalid level.

[0023] For example, the drive control circuit 110 can be implemented as an IGBT driver chip and have a short-circuit detection function. It can determine the current drive voltage signal to be output to the IGBT based on internal processing. The gate voltage control circuit 120 is used to provide a gate voltage at the gate based on the drive voltage signal and discharge the gate voltage in the event of a short-circuit fault at the IGBT.

[0024] For example, when the driving voltage signal is at a valid level (e.g., 15V), the gate voltage control circuit is used to provide a gate voltage at the gate of the IGBT based on the driving voltage signal, thereby driving the IGBT to turn on, and when the driving voltage signal is at an invalid level (e.g., -8V) or does not exist, the gate of the IGBT cannot obtain the driving power, so the gate voltage will be released, and the gate voltage control circuit can provide a related discharge path, so that the IGBT will be turned off. Of course, considering the output capacity of the driver chip, its driving voltage signal may not be able to directly drive the IGBT, but may be driven by an additional driving stage circuit (e.g., a push-pull structure of transistors in series, as will be shown in FIG). Figure 3 ) to provide +15V and -8V voltages to the gate of the IGBT, and the signal output by the drive control circuit 110 is provided to the drive stage circuit via the gate voltage control circuit to control the on and off of the upper and lower transistors.

[0025] like Figure 2B As shown, the gate voltage control circuit 120 may include a first capacitor C1, a charge-discharge circuit CHA, and a capacitor discharge path. The charge-discharge circuit CHA can charge the first capacitor C1 based on the drive voltage signal and, in the event of a short-circuit fault at the IGBT, discharge the gate voltage (directly discharge the gate voltage of the IGBT, or, in the case of a driver stage circuit, discharge the gate voltage of the IGBT by discharging the control electrode voltage of the transistor in the driver stage circuit). In addition, the voltage on the first capacitor can also be discharged to a low voltage reference terminal in the drive control circuit via the capacitor discharge path.

[0026] For example, when the driving voltage signal is at an effective level, the voltage on the first capacitor C1 will gradually increase, and the first capacitor is connected to the gate of the IGBT via a charging and discharging circuit (directly connected or connected via a driving stage circuit), so that the gate voltage can also gradually increase. When the drive control circuit detects a short circuit fault, the drive control circuit will output a low-level driving voltage signal or not output a driving voltage signal, so that the gate voltage will discharge. Optionally, taking the first capacitor being directly connected to the gate of the IGBT via a charging and discharging circuit as an example, a short circuit fault occurs at the IGBT, the drive control circuit detects the short circuit fault and performs a short-circuit protection action (in a very short first time period when the driver chip just starts to perform short-circuit protection), the charging and discharging circuit discharges the gate voltage to the first capacitor, and after the first time period, the gate voltage and the capacitor voltage are discharged together via the capacitor discharge path. For example, the drive control circuit may include a low voltage reference terminal (for example, providing a voltage of -8 V) and a second output terminal, and a switch is connected between the low voltage reference terminal and the second output terminal (disconnected during normal operation), and the discharge path of the gate voltage may pass through the second output terminal OUTL→switch→low voltage reference terminal, and the discharge path of the voltage on the first capacitor C1 may also pass through the second output terminal OUTL→switch→low voltage reference terminal.

[0027] The charge and discharge auxiliary circuit 130 may be connected to the gate voltage control circuit to slow down the discharge speed of the gate voltage in the event of a short circuit fault at the IGBT.

[0028] pass Figures 2A-2B The driving circuit 100 shown can realize the discharge of the gate voltage only through the gate voltage control circuit. The discharge speed of the gate voltage is slowed down by adding the charge and discharge auxiliary circuit 130. As analyzed above, the voltage VCE between the collector and emitter of the IGBT can be reduced, thereby avoiding damage to the IGBT.

[0029] Figure 3 Shown Figures 2A-2B Further structure of the driving circuit shown.

[0030] like Figure 3As shown, the charge and discharge circuit of the gate voltage control circuit 120 may include a first charging path and a discharging path. The first charging path is used to charge the first capacitor based on the drive voltage signal before the drive control circuit detects the short-circuit fault; and the discharging path is used to discharge the gate voltage in the event of a short-circuit fault at the IGBT (for example, discharging the gate voltage of the IGBT (or the voltage of the control electrode of the drive stage circuit) to the first capacitor within a first time period, and discharging the gate voltage of the IGBT (or the voltage of the control electrode of the drive stage circuit) to a low voltage reference terminal (for example, connected to a -8V voltage) after the first time period in coordination with the capacitor discharge path (resistor Rcd) and the relevant discharge path within the drive control chip).

[0031] For example, the first charging path includes a first resistor R1, and the discharging path includes a discharging resistor Rd. A first end of the first resistor R1 is connected to a first output end of a driving control circuit, and a second end of the first resistor R1 is connected to a first end of the first capacitor C1.

[0032] Optionally, the charge and discharge auxiliary circuit 130 may include an additional resistor Ra, which is connected in parallel with the first resistor R1 before the short-circuit fault is detected to form a second charging path to jointly charge the first capacitor, and in response to detecting a short-circuit fault at the IGBT, the additional resistor is connected in series in the discharge path.

[0033] The second charging path may include a first diode D1 and a second resistor R2 (i.e., an additional resistor Ra) connected in series, wherein the anode of the first diode D1 is connected to the first output terminal, the cathode of the first diode D1 is connected to the first end of the second resistor, and the second end of the second resistor is connected to the first end of the first capacitor. A first end of a discharge resistor Rd (serving as a third resistor) is connected to the cathode of the first diode D1, and a second end of the discharge resistor Rd is connected to the gate of the IGBT.

[0034] In this way, when charging the first capacitor, since the first charging path and the second charging path jointly charge the first capacitor C1, the voltage of the first capacitor C1 rises faster, so it can rise to a higher voltage within a limited turn-on time period (for example, the IGBT itself has failed before being turned on but has not been detected, so the drive control circuit still outputs a drive voltage signal with a valid level, but a short-circuit fault will be detected in a shorter time and the output of the drive voltage signal with a valid level will stop), so that a longer discharge time is required when discharging the voltage on the first capacitor subsequently. Furthermore, when discharging the IGBT's gate voltage (or the driver circuit's gate voltage), due to the unidirectional conduction characteristics of diode D1, the second resistor R2 is also considered to be connected in series with the third resistor R3 between the IGBT's gate (or the driver circuit's gate voltage) and the first capacitor. Therefore, the gate voltage is discharged through the third and second resistors. Since the second resistor can have a larger resistance than the first resistor, the total resistance (R3+R2) along the discharge current path can be increased compared to the case where no charge-discharge auxiliary circuit is provided (R3+R1), thereby slowing down the discharge rate of the IGBT's gate voltage (or the driver circuit's gate voltage). Furthermore, since the voltage across first capacitor C1 is also relatively high (compared to the case where no charge-discharge auxiliary circuit is provided) at the end of charging, the difference between the gate voltage (or the driver circuit's gate voltage) and the voltage across first capacitor C1 is also smaller, thus slowing down the discharge rate of the gate voltage (or the driver circuit's gate voltage).

[0035] For example, Figure 3 As shown, the driver stage circuit can be composed of two transistors connected in series, and the types of the two transistors are opposite ( Figure 3 , which exemplarily shows that the upper tube is an NPN type and the lower tube is a PNP type). When discharging the gate voltage, the discharge current will flow through the emitter and collector of the transistor below to the low voltage reference terminal. Due to the nature of the transistor, the current between the emitter and the collector will be controlled by the base current, and the base current during discharge can be expressed as (U2-U1) / (R2+R3), where U2 is the voltage of the control electrode of the driving electrode circuit (the voltage of the bases of the two transistors), U1 is the voltage of the first end of the first capacitor, and R2 and R3 are the resistance values ​​of the second resistor and the third resistor. Therefore, as described above, when the second charging path is added, so that U1 increases or the total resistance on the discharge path increases, the base current can be reduced, thereby reducing the discharge current from the gate voltage to the low voltage reference terminal.

[0036] It can be seen that by adding the second charging path, the voltage of the first capacitor can be increased to a higher voltage within a limited on-time period. In addition, when the gate voltage is discharged, the discharge speed of the gate voltage is correspondingly slowed down by the increased total resistance value of the discharge path, which can reduce the VCE voltage between the collector and emitter of the IGBT, thereby avoiding damage to the IGBT.

[0037] On the other hand, under normal circumstances, when the IGBT is turned on, it will work in the saturation region. Here, saturation means that in this region, VCE has dropped to less than the saturation value Ucesat (usually a very small value). If a short circuit occurs at this time and the current Ic flowing through the IGBT increases to near the maximum value, VCE will rise to a very high voltage (for example, for Figure 1 The IGBT of an upper bridge arm in the three-phase inverter shown may be equal to the DC bus voltage), so the IGBT exits the saturation region and operates in the active region, that is, desaturation.

[0038] Therefore, a desaturation detection circuit is generally included in the drive control circuit, for example, for detecting the desaturation state of the IGBT, and the IGBT operates in a saturated state under normal working conditions, so the desaturation state can be associated with a short-circuit fault, and thus can act as a short-circuit detection circuit. Typically, the drive circuit includes a desaturation protection circuit for generating and providing a desaturation detection signal to the drive control circuit (the desaturation detection circuit), so that when the drive control circuit determines the desaturation state of the IGBT based on the desaturation detection signal, the drive control circuit stops outputting the drive voltage signal or sets the drive voltage signal to an invalid level to turn off the IGBT. For example, as previously referenced Figure 2A-3 The described drive circuit can turn off the IGBT in response to the detection result of the desaturation detection circuit.

[0039] As an example, Figure 4 A circuit diagram of a desaturation detection circuit and a desaturation protection circuit is shown.

[0040] like Figure 4 As shown, the desaturation detection circuit may include a comparator, a reference power supply (providing a reference voltage, such as 9V) and a control logic circuit; the desaturation protection circuit may include a current source, a resistor R DESAT , diode D DESAT , capacitor C DESAT and diode D prot .

[0041] When the IGBT is working normally, the voltage VCE between the collector and emitter is very low, generally between 1V and 3V. However, after the IGBT is desaturated due to a short circuit fault, the voltage VCE will rise rapidly. The desaturation detection circuit in the drive control circuit can set a reference voltage in advance, such as 9V. When the voltage VCE exceeds 9V, the IGBT will be shut down. For example, the drive control circuit (for example, the driver chip) has a built-in 500uA constant current source. When the IGBT is working normally, the voltage VCE is very small, and a current of 500uA flows through the resistor R DESAT , diode D DESAT Flows through the IGBT, capacitor C DESAT The voltage on the diode D is also less than the reference voltage 9V, and the comparator will not flip; when the IGBT desaturates, VCE rises sharply, and the diode D DESAT Cut-off, 500uA current can only flow to capacitor C DESAT Charging, when C DESAT When the voltage on the chip exceeds 9V, the comparator inside the chip flips, the control logic circuit reports an error, and the IGBT is turned off.

[0042] In the art, short-circuit faults of IGBTs can be divided into type 1 short-circuit faults (SC1) and type 2 short-circuit faults (SC2).

[0043] A Type 1 short-circuit fault (SC1) occurs during the IGBT's turn-on transient, i.e., during the IGBT's turn-on phase (when the gate voltage transitions from negative to positive). This means that no short-circuit fault occurs in the system before the IGBT is turned on. A Type 2 short-circuit fault (SC2) occurs during the IGBT's on-state phase, i.e., during the IGBT's conduction phase (when the gate voltage remains positive and the device is conducting forward), when the device current suddenly increases due to external factors.

[0044] In order to better realize the shutdown of IGBT under both short-circuit faults, for example, it is hoped that short-circuit protection can be performed under smaller short-circuit current and smaller peak voltage under both short-circuit faults, and according to Figure 4 The circuit structure shown in the figure obtains the test waveforms for the first type of short circuit fault and the second type of short circuit fault. There are certain defects in the circuit structure. For example, it may be desirable to enable faster short circuit protection under the first type of short circuit fault, while it may be desirable to increase the desaturation time (capacitor C DESAT The time for the voltage on the collector to rise to 9V is set to avoid the interval where the collector current Ic is relatively large (in this way, the short-circuit protection (for example, the operation of shutting down the IGBT) can be performed at a smaller short-circuit current, thereby reducing the peak voltage of the IGBT). Therefore, the embodiments of the present application are Figure 4 The circuit was further improved.

[0045] like Figure 5 As shown, in Figure 2A-Figure 3 Based on the circuit structure shown in FIG, the structure of the desaturation protection circuit is further shown. Figure 5 As shown, the desaturation protection circuit may include: a second capacitor C2 (equivalent to Figure 4 C shown DESAT ), connected between the second output terminal (I / O terminal, shown as DESAT, the first output terminal mentioned above is shown as OUTH) of the drive control circuit and the emitter of the IGBT; a first current source I1 (equivalent to Figure 4 The 500uA constant current source shown) and the second current source I2 are used to charge the second capacitor C2; and the series branch of the resistor and the diode (equivalent to Figure 4 The resistor R shown DESAT and diode D DESAT ), the series branch being connected between the second capacitor C2 and the collector of the IGBT, wherein when a voltage value of a voltage signal at the second output terminal of the drive control circuit, serving as the desaturation detection signal, exceeds a threshold value, the drive control circuit determines that the IGBT is in a desaturation state.

[0046] Optionally, the first current source I1 can be a current source within the drive control circuit and provide current to the second capacitor C2 via the second output terminal (shown as DESAT), and the second current source I2 is an external current source of the drive control circuit. Optionally, the current provided by the first current source I1 has a current value of 500uA, and the current provided by the second current source I2 has a current value of 2000uA. Optionally, the first current source I1 can be provided by connecting an external power supply of 15V to the VDD terminal and connecting an internal resistor between the VDD terminal and the DESAT terminal.

[0047] based on Figure 5 In the circuit shown, the sources for charging the second capacitor may include a first current source I1, a second current source I2, and a current corresponding to a positive voltage change (du / dt) of the VCE of the IGBT. That is, when the voltage change (du / dt) of the VCE of the IGBT is positive, it can be used to charge the second capacitor, and when it is negative, it can be used to discharge the second capacitor.

[0048] For example, for a type of short-circuit fault, the drive control circuit can be used to detect the desaturation state of the IGBT immediately after starting to output the drive control signal normally. When a short-circuit fault occurs in the IGBT, the first current source and the second current source as a whole charge the second capacitor more significantly relative to the series branch.

[0049] For example, in the case of a short-circuit fault, since the voltage VCE of the IGBT is always high, the voltage variation (du / dt) has both positive and negative values, so charging the second capacitor is mainly completed by the first current source I1 and the second current source I2, so the desaturation time is determined by the charging time. In this case, due to the Figure 4 The circuit shown incorporates a second current source I2, so that short-circuit protection (the process of shutting down the IGBT) can be performed more quickly. In addition, in the case of a type I short-circuit fault, performing the short-circuit protection operation as quickly as possible can ensure a smaller short-circuit current and peak voltage.

[0050] For another example, for a Type II short-circuit fault, the drive control circuit is further used to detect the desaturation state of the IGBT during the normal conduction period of the IGBT. When a short-circuit fault occurs in the normally conducted IGBT, the series branch charges the second capacitor more significantly than the first current source and the second current source as a whole.

[0051] For example, in the case of a Class II short-circuit fault, the voltage variation (du / dt) of the IGBT voltage VCE is a large value after the saturation period (the corresponding current value is much larger than the current value of the current source). As mentioned above, in order to increase the desaturation time in the case of a Class II short-circuit fault, so as to avoid short-circuit protection when the current is at its maximum value, a third capacitor can be provided in parallel with the second capacitor (or the capacitance value of the second capacitor can be increased). Therefore, the current corresponding to the voltage variation (du / dt) charges the capacitor structure with a larger capacitance value, so relative to Figure 4 The circuit shown can increase the desaturation time, thereby avoiding the maximum current for short-circuit protection. Furthermore, although increasing the capacitance value may affect the capacitor charging time during a Class I short-circuit fault, the introduction of a second current source increases the charging current, enabling short-circuit protection to be achieved as quickly as possible even under a Class I short-circuit fault. Furthermore, the second current source has no significant impact on the capacitor charging process (primarily determined by du / dt) during a Class II short-circuit fault, thus meeting the requirements for both Class I and Class II short-circuit faults.

[0052] Although the above description of the desaturation protection circuit is consistent with the reference Figure 2A-Figure 3 The circuits described are combined with the described ones, but it should be understood that the desaturation protection circuit can also be combined with a driving circuit that does not include a charge and discharge auxiliary circuit.

[0053] For example, in some other embodiments, a driving circuit for an insulated gate bipolar transistor (IGBT) may include: a driving control circuit, a gate voltage control circuit, and a desaturation protection circuit.

[0054] Similarly, the drive control circuit can be configured to output a drive voltage signal at a first output terminal to control the switching state of the IGBT. The gate voltage control circuit can be configured to provide a gate voltage at the gate based on the drive voltage signal and discharge the gate voltage in the event of a short circuit fault at the IGBT.

[0055] The desaturation protection circuit can be compared with the previous reference Figure 5 The same as described, that is, it may include: a second capacitor, connected between the second output terminal of the drive control circuit and the emitter of the IGBT; a first current source and a second current source, for charging the second capacitor; and a series branch of a resistor and a diode, the series branch being connected between the second capacitor and the collector of the IGBT, wherein when the voltage value of the voltage signal at the second output terminal exceeds a threshold value, the drive control circuit determines the desaturation state of the IGBT, wherein the desaturation state is at least associated with the short-circuit fault.

[0056] More details of each circuit component can be found in the previous description, so they will not be repeated here.

[0057] It can be seen that in the embodiments of the present application, in order to reduce the voltage spike during the short-circuit protection process, improvements can be made in at least one of the desaturation detection stage and the short-circuit protection stage. For example, in the desaturation detection stage, by adding a current source, short-circuit protection can be performed as quickly as possible under a Class I short-circuit fault to increase safety, and by increasing the capacitance value under a Class II fault to avoid large current while still meeting the action time requirements of a Class I short-circuit fault; in the short-circuit protection stage, by adding a charging path, the discharge speed of the gate voltage can be slowed down, thereby reducing the voltage spike between the collector and emitter of the IGBT.

[0058] According to another aspect of the present disclosure, an electronic device is provided, which includes the driving circuit as described above.

[0059] According to another aspect of the present disclosure, a vehicle is provided, comprising a drive circuit and / or electronic device as described above. The vehicle may be an electrified vehicle, such as a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), an extended-range electric vehicle (Range Extended EV), or a fuel cell electric vehicle (FCEV). The vehicle may also be a hydrogen-powered vehicle.

[0060] In addition, it should be noted that although the embodiments of the method according to the example embodiments of the present disclosure are described above in separate forms, the features described in each embodiment described above can be combined in any way in a single embodiment without departing from the concept of the present disclosure, and the features described in a single embodiment can also be implemented separately in multiple embodiments.

[0061] Although the present disclosure has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made to the present disclosure without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents. Therefore, the scope of the present disclosure should not be limited to the above-described embodiments, but should be determined not only by the appended claims but also by the equivalents of the appended claims.

Claims

1. A drive circuit for an insulated gate bipolar transistor (IGBT), comprising: a drive control circuit, configured to output a drive voltage signal at a first output terminal to control a switching state of the IGBT, and to stop outputting the drive voltage signal or set the drive voltage signal to an invalid level when a short circuit fault is detected at the IGBT; a gate voltage control circuit for providing a gate voltage at the gate of the IGBT based on the drive voltage signal and discharging the gate voltage in the event of a short circuit fault at the IGBT; as well as A charge and discharge auxiliary circuit is connected to the gate voltage control circuit and is used to slow down the discharge speed of the gate voltage in the event of a short circuit fault at the IGBT.

2. The driving circuit according to claim 1, wherein: The gate voltage control circuit includes a first capacitor, a charge and discharge circuit and a capacitor discharge path, When a short circuit fault occurs at the IGBT, the drive control circuit detects the short circuit fault and performs a short circuit protection action within a first time period, the charge and discharge circuit discharges the gate voltage to the first capacitor, and after the first time period, the gate voltage and the voltage on the first capacitor are discharged together via the capacitive discharge path.

3. The driving circuit according to claim 1 , further comprising: The driving stage circuit includes a first transistor and a second transistor connected in series, wherein the control electrodes of the first transistor and the second transistor are connected to the gate voltage control circuit, and the emitter electrodes are connected to the gate of the IGBT. The gate voltage control circuit provides the gate voltage via the first transistor in the driving stage circuit, and the gate voltage is discharged via the second transistor in the driving stage circuit, and the discharge speed depends on the current of the control electrode of the second transistor.

4. The driving circuit according to claim 3, wherein: The gate voltage control circuit includes a first capacitor, a charge and discharge circuit and a capacitor discharge path, When a short-circuit fault occurs at the IGBT, the drive control circuit detects the short-circuit fault and performs a short-circuit protection action within a first time period, the charge-discharge circuit discharges the voltage of the control electrodes of the first transistor and the second transistor to the first capacitor, and after the first time period, the voltage of the control electrodes and the voltage on the first capacitor are discharged together via the capacitor discharge path.

5. The driving circuit according to claim 2 or 4, wherein: The charging and discharging circuit of the gate voltage control circuit includes: a first charging path for charging the first capacitor based on the driving voltage signal before the driving control circuit detects the short circuit fault; and A discharge path is used to discharge the gate voltage in the event of a short circuit fault at the IGBT. The driving circuit according to claim 5 , wherein: The charge and discharge auxiliary circuit includes an additional resistor, Before the short-circuit fault is detected, the additional resistor and the first charging path are connected in parallel to jointly charge the first capacitor, and in response to detecting the short-circuit fault at the IGBT, the additional resistor is connected in series in the discharge path.

7. The driving circuit according to claim 5, wherein: The charge-discharge auxiliary circuit includes a second charging path connected in parallel with the first charging path, configured to charge the first capacitor in parallel together with the first charging path based on the driving voltage signal before the short circuit fault is detected.

8. The driving circuit according to claim 7, wherein: The first charging path includes a first resistor, a first end of the first resistor is connected to the first output terminal, and a second end of the first resistor is connected to the first end of the first capacitor; The second charging path includes a first diode and a second resistor connected in series, an anode of the first diode is connected to the first output terminal, a cathode of the first diode is connected to a first end of the second resistor, and a second end of the second resistor is connected to the first end of the first capacitor; The discharge path includes a third resistor, a first end of the third resistor is connected to the cathode of the first diode, and a second end of the third resistor is connected to the gate of the IGBT.

9. The driving circuit according to claim 1, further comprising: Desaturation protection circuit, used to provide a desaturation detection signal, When the drive control circuit determines the desaturation state of the IGBT based on the desaturation detection signal, the drive control circuit stops outputting the drive voltage signal or sets the drive voltage signal to an invalid level. The desaturation state of the IGBT is at least associated with the short-circuit fault.

10. The driving circuit according to claim 9, wherein: The desaturation protection circuit comprises: a second capacitor connected between the second output terminal of the drive control circuit and the emitter of the IGBT; A first current source and a second current source, configured to charge the second capacitor; and a series branch of a resistor and a diode, the series branch being connected between the second capacitor and the collector of the IGBT, When a voltage value of a voltage signal at the second output terminal of the drive control circuit, serving as the desaturation detection signal, exceeds a threshold, the drive control circuit determines that the IGBT is in a desaturation state.

11. The driving circuit according to claim 10, wherein: The first current source is a current source inside the drive control circuit and provides current to the second capacitor via the second output terminal, and the second current source is an external current source of the drive control circuit.

12. The driving circuit according to claim 10, wherein: The drive control circuit is further configured to detect the desaturation state of the IGBT immediately after starting to output the drive control signal normally. When a short-circuit fault occurs on the IGBT, the first current source and the second current source as a whole charge the second capacitor more significantly than the series branch.

13. The driving circuit according to claim 10, wherein: The drive control circuit is further configured to detect a desaturation state of the IGBT during normal conduction of the IGBT. When a short-circuit fault occurs in the normally-on IGBT, the series branch charges the second capacitor more significantly than the entirety of the first current source and the second current source.

14. A drive circuit for an insulated gate bipolar transistor (IGBT), comprising: A drive control circuit, configured to output a drive voltage signal at the first output terminal to control the switching state of the IGBT; a gate voltage control circuit for providing a gate voltage at the gate based on the drive voltage signal and enabling discharge of the gate voltage in the event of a short circuit fault at the IGBT; as well as Desaturation protection circuit, including: a capacitor connected between the second output terminal of the drive control circuit and the emitter of the IGBT; a first current source and a second current source, configured to charge the capacitor; and a series branch of a resistor and a diode, the series branch being connected between the capacitor and the collector of the IGBT, When the voltage value of the voltage signal at the second output terminal exceeds a threshold, the drive control circuit determines a desaturation state of the IGBT, wherein the desaturation state is at least associated with the short-circuit fault.

15. The driving circuit according to claim 14, wherein: The gate voltage control circuit includes a first capacitor, a charge and discharge circuit and a capacitor discharge path, When a short circuit fault occurs at the IGBT, the drive control circuit detects the short circuit fault and performs a short circuit protection action within a first time period, the charge and discharge circuit discharges the gate voltage to the first capacitor, and after the first time period, the gate voltage and the voltage on the first capacitor are discharged together via the capacitive discharge path.

16. The driving circuit according to claim 14, further comprising: The driving stage circuit includes a first transistor and a second transistor connected in series, wherein the control electrodes of the first transistor and the second transistor are connected to the gate voltage control circuit, and the emitter electrodes are connected to the gate of the IGBT. The gate voltage control circuit provides the gate voltage via the first transistor in the driving stage circuit, and the gate voltage is discharged via the second transistor in the driving stage circuit, and the discharge speed depends on the current of the control electrode of the second transistor.

17. The driving circuit according to claim 16, wherein: The gate voltage control circuit includes a first capacitor, a charge and discharge circuit and a capacitor discharge path, When a short circuit fault occurs at the IGBT, the drive control circuit detects the short circuit fault and performs a short circuit protection action within a first time period, the charge and discharge circuit discharges the voltage of the control electrodes of the first transistor and the second transistor to the first capacitor, and after the first time period, the voltage of the control electrode and the voltage on the first capacitor are discharged together via the capacitor discharge path.

18. The driving circuit according to claim 14, wherein: The first current source is a current source inside the drive control circuit and provides current to the second capacitor via the second output terminal, and the second current source is an external current source of the drive control circuit.

19. The driving circuit according to claim 14, wherein: The drive control circuit is further configured to detect the desaturation state of the IGBT immediately after starting to output the drive control signal normally. When a short-circuit fault occurs on the IGBT, the first current source and the second current source as a whole charge the capacitor more significantly than the series branch.

20. The driving circuit according to claim 14, wherein: The drive control circuit is further configured to detect a desaturation state of the IGBT during normal conduction of the IGBT. When a short-circuit fault occurs in the normally-on IGBT, the series branch charges the capacitor more significantly than the entirety of the first current source and the second current source.

21. The driving circuit according to claim 14, wherein: The desaturation protection circuit further includes a second capacitor connected in parallel with the capacitor.

22. An electronic device comprising the driving circuit according to any one of claims 1 to 21.

23. A vehicle comprising the drive circuit according to any one of claims 1 to 21 and / or the electronic device according to claim 22.

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