IGBT protection circuit, motor control circuit and vehicle

Abstract

The utility model provides an IGBT protection circuit, a motor control circuit and a vehicle, the IGBT protection circuit comprises a current detection module, a boost module and a driving module, the current detection module detects whether an IGBT is over-current, when the current output by the emitter of the IGBT is greater than or equal to a preset current threshold, the current detection module outputs a first trigger signal for representing the over-current of the IGBT, and when the current output by the emitter of the IGBT is greater than or equal to the preset current threshold, the current detection module outputs a second trigger signal for representing the over-current of the IGBT. When the boost module receives the first trigger signal, the boost module boosts the voltage of the protection end of the driving module so as to trigger the desat function of the driving module, and the driving end of the driving module outputs a first turn-off signal to turn off the IGBT for a first preset duration. It can be understood that the first preset duration is long, even if the overcurrent of the IGBT is large, the current can be reduced within the first preset duration when the IGBT is turned off, the safety of the IGBT is not affected, and the efficiency of the motor controller is not affected.

Description

Technical Field

[0001] This application relates to the field of motor control technology, specifically to an IGBT protection circuit, a motor control circuit, and a vehicle. Background Technology

[0002] The motor controller plays a crucial role in the three-electric system of new energy vehicles, directly determining key performance parameters such as motor output power, torque, and speed. The insulated-gate bipolar transistor (IGBT), the chopper component in the motor controller, is highly susceptible to failure, and IGBT failure can lead to power interruption during vehicle operation. Therefore, preventing IGBT failure is of paramount importance in motor control design.

[0003] In related technologies, when the IGBT output current is too large, the current sensor detects the excessive IGBT output current and outputs a corresponding voltage value, which causes the comparator output level to flip to a low level. The low level invalidates the CE pin of the level conversion module, the PWM signal is blocked, and the drive module normally turns off the IGBT through the g pin.

[0004] However, in this circuit, the normal turn-off time of the IGBT is very short. If the overcurrent at the IGBT is large, the di / dt at Ls will still be very large, resulting in an excessively large peak voltage U, which can damage the IGBT. Although some related technologies increase the IGBT's turn-off time by increasing the resistance value of the IGBT gate connection, this method will reduce the efficiency of the motor controller.

[0005] It should be noted that the information disclosed in the background section of this application is intended only to enhance the understanding of the general background of this application, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0006] In view of this, this application provides an IGBT protection circuit, a motor control circuit, and a vehicle to address the problem that in the prior art, the normal turn-off time of the IGBT is very short. If the overcurrent at the IGBT is large, the di / dt at Ls will still be very large, resulting in an excessively large peak voltage U, which can damage the IGBT. Although in some related technologies, the turn-off time of the IGBT is increased by increasing the resistance value of the IGBT gate connection resistor, this method will reduce the efficiency of the motor controller.

[0007] In a first aspect, embodiments of this application provide an IGBT protection circuit, including a current detection module, a boost module, and a drive module, wherein the drive module has a protection terminal and a drive terminal: wherein,

[0008] The input terminal of the current detection module is electrically connected to the emitter of the IGBT. The current detection module is configured to send a first trigger signal to the boost module when it detects that the current output by the emitter of the IGBT is greater than or equal to a preset current threshold.

[0009] The control terminal of the boost module is electrically connected to the output terminal of the current detection module, and the boost module is electrically connected to the protection terminal of the drive module. The boost module is configured to increase the voltage at the protection terminal of the drive module when the first trigger signal is received.

[0010] The driving terminal of the driving module is electrically connected to the gate of the IGBT. The driving module is configured to output a first turn-off signal through the driving terminal to turn off the IGBT for a first preset duration when the voltage of the protection terminal rises to a preset voltage threshold.

[0011] In this embodiment, the IGBT protection circuit includes a current detection module, a boost module, and a drive module. The current detection module detects whether the IGBT is overcurrent. When the current output from the emitter of the IGBT is greater than or equal to a preset current threshold, the current detection module outputs a first trigger signal to characterize the IGBT overcurrent. When the boost module receives the first trigger signal, it increases the voltage at the protection terminal of the drive module, thereby triggering the desat function of the drive module. The drive terminal of the drive module then outputs a first turn-off signal to turn off the IGBT for a first preset duration. It is understood that the first preset duration is relatively long; even if the IGBT overcurrent is large, the current can be reduced within the first preset duration of IGBT turn-off, without affecting the safety of the IGBT or the efficiency of the motor controller.

[0012] In one possible implementation, the current detection module includes a current detection unit and a first trigger signal generation unit; wherein,

[0013] The current detection unit is electrically connected to the emitter of the IGBT, and the current detection unit is configured to generate a corresponding voltage signal based on the current signal output from the emitter of the IGBT.

[0014] The first trigger signal generation unit is electrically connected to the current detection unit to receive the voltage signal output by the current detection unit. The first trigger signal generation unit is configured to send a first trigger signal to the boost module when the voltage signal is greater than a preset reference voltage.

[0015] In one possible implementation, the current detection unit includes a Hall sensor; the first trigger signal generation unit includes a comparator.

[0016] In one possible implementation, the boost module includes: a first switching unit and a second switching unit, wherein the control terminal of the first switching unit is connected to the current detection module, and the output terminal of the first switching unit is connected to the control terminal of the second switching unit;

[0017] The second switch unit is connected in series with the protection terminal of the drive module;

[0018] The first switching unit is configured to control the second switching unit to disconnect when the first trigger signal is received, so that the protection terminal of the drive module is left floating.

[0019] In one possible implementation, the first switching unit includes an NMOS transistor, a capacitive isolator, or a magnetic isolator;

[0020] The second switching unit includes an optocoupler or a transistor.

[0021] In one possible implementation, the circuit further includes:

[0022] The delay module has its input terminal electrically connected to the output terminal of the current detection module, and is configured to output the first trigger signal after a preset delay time.

[0023] A level conversion module, wherein the trigger terminal of the level conversion module is connected to the output terminal of the delay module, and the output terminal of the level conversion module is connected to the input terminal of the drive module;

[0024] The level conversion module is configured to output a second trigger signal to the driving module when the trigger terminal of the level conversion module receives the first trigger signal;

[0025] The drive module is configured to, upon receiving the second trigger signal, output a second shutdown signal through the drive terminal to shut down the IGBT for a second preset duration.

[0026] In one possible implementation, the delay module includes an RC delay circuit.

[0027] Secondly, embodiments of this application provide a motor control circuit, including: the IGBT protection circuit described in any one of the first aspects.

[0028] Thirdly, embodiments of this application provide a vehicle, including: the motor control circuit described in the second aspect. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of an IGBT protection circuit in related technologies;

[0031] Figure 2 This is a schematic diagram of the structure of an IGBT protection circuit provided in an embodiment of this application;

[0032] Figure 3 This is a schematic diagram of the structure of a current detection module provided in an embodiment of this application;

[0033] Figure 4 This is a schematic diagram of a boost module provided in an embodiment of this application;

[0034] Figure 5 This is a schematic diagram of another boost module provided in an embodiment of this application;

[0035] Figure 6 This is a schematic diagram of another boost module provided in an embodiment of this application;

[0036] Figure 7 This is a schematic diagram of another IGBT protection circuit provided in an embodiment of this application;

[0037] Figure 8 This is a schematic diagram of the structure of a delay module provided in an embodiment of this application;

[0038] Figure 9 This is a schematic diagram of another IGBT protection circuit provided in an embodiment of this application. Detailed Implementation

[0039] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0040] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0041] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0042] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0043] The motor controller plays a crucial role in the three-electric system of new energy vehicles, directly determining key performance parameters such as motor output power, torque, and speed. The insulated-gate bipolar transistor (IGBT), the chopper component in the motor controller, is highly susceptible to failure, and IGBT failure can lead to power interruption during vehicle operation. Therefore, preventing IGBT failure is of paramount importance in motor control design.

[0044] In related technologies, when the IGBT output current is too large, the current sensor detects the excessive IGBT output current and outputs a corresponding voltage value, which causes the comparator output level to flip to a low level. The low level invalidates the CE pin of the level conversion module, the PWM signal is blocked, and the drive module normally turns off the IGBT through the g pin.

[0045] For ease of understanding, this application provides a schematic diagram of the structure of an IGBT protection circuit in the related art.

[0046] See Figure 1 This is a schematic diagram of the structure of an IGBT protection circuit in related technologies. For example... Figure 1 As shown, the IGBT protection circuit includes a short-circuit protection sub-circuit 101 and an overcurrent protection sub-circuit 102. The short-circuit protection sub-circuit 101 includes a gate driver module, a fifth resistor R5, a third capacitor C3, a sixth resistor R6, and a second diode D2. The overcurrent protection sub-circuit 102 includes a level shifting module (Transceiver), a gate driver module, a Hall sensor (Hall), a comparator C2, and the fifth resistor R5.

[0047] It should be pointed out that, Figure 1 The short-circuit protection sub-circuit 101 and overcurrent protection sub-circuit 102 share the same drive module Gate driver and the fifth resistor R5. Additionally... Figure 1 The DC-link in the circuit is a supporting capacitor used to ensure stable operation of the power control circuit and filter out stray inductance on the bus. Ls is the parasitic inductance on the copper bus between the IGBT and the DC-link, and Lm is the equivalent inductance of the motor winding inductance. These are not part of the IGBT protection circuit.

[0048] exist Figure 1 In the circuit shown, the current flowing through the IGBT is Ip. When the IGBT is turned on, the current Ip flows through the inductor Ls. When the IGBT is turned off, the current flowing through Ls will generate a voltage spike. The magnitude of the voltage spike is U = Ls × di / dt, where di / dt is the current turn-off slope.

[0049] When an IGBT experiences an overcurrent fault, Ip increases, but the current value of Ip is insufficient to handle a short-circuit fault. The voltage rise between the collector and emitter of the IGBT is not significant, failing to trigger the desat function. Instead, the Hall sensor detects the increased current, leading to an increase in the Hall output voltage. Comparator C2 outputs a low level, which blocks the control signal (i.e., PWM signal) output by the level shifter (Transceiver) to the gate driver. The gate driver then drives the IGBT to turn off normally via the drive terminal g, with the IGBT turn-off duration being t1.

[0050] When an IGBT experiences a short-circuit fault, the inductor Lm is shorted, and the current flowing through the IGBT rapidly increases to more than three times the normal current. The voltage between the collector and emitter of the IGBT increases rapidly, causing a significant rise in the voltage at the desat terminal of the gate driver, thus triggering the desat function. The desat function causes the gate driver to turn off the IGBT through the g terminal, and the turn-off time t2 is several times longer than the normal turn-off time t1 of the IGBT, thereby reducing the value of di / dt. The voltage spike U will also decrease accordingly, thus protecting the IGBT from damage due to overvoltage at the CE terminal.

[0051] Obviously, when an IGBT experiences an overcurrent fault, its turn-off time is very short. If the overcurrent at the IGBT is large, the di / dt at Ls will remain high, leading to an excessively large peak voltage U and potentially damaging the IGBT. Although some related technologies increase the IGBT's turn-off time by increasing the value of the fifth resistor R5, this method reduces the efficiency of the motor controller.

[0052] To address the aforementioned issues, the IGBT protection circuit provided in this application includes a current detection module, a boost module, and a drive module. The current detection module detects whether the IGBT is overcurrent. When the current output from the IGBT's emitter is greater than or equal to a preset current threshold, the current detection module outputs a first trigger signal to characterize the IGBT overcurrent. Upon receiving this first trigger signal, the boost module increases the voltage at the protection terminal of the drive module, thereby triggering the desat function of the drive module. The drive terminal of the drive module then outputs a first turn-off signal to turn off the IGBT for a first preset duration. For example, the turn-off duration after triggering the desat function can be set to t2. It is understood that a relatively long first preset duration allows the current to decrease within the first preset turn-off duration even if the IGBT overcurrent is significant, without affecting the IGBT's safety or the efficiency of the motor controller. A detailed description is provided below in conjunction with the accompanying drawings.

[0053] See Figure 2 This is a schematic diagram of an IGBT protection circuit provided in an embodiment of this application. Figure 2 As shown, the IGBT protection circuit in this application includes a current detection module 201, a boost module 202, and a gate driver module. It should be noted that... Figure 2 The DC-link in the circuit is a supporting capacitor used to ensure stable operation of the power control circuit and filter out stray inductance on the bus. Ls is the parasitic inductance on the copper bus between the IGBT and the DC-link, and Lm is the equivalent inductance of the motor winding inductance. These are not part of the IGBT protection circuit.

[0054] like Figure 2 As shown, the input terminal of the current detection module 201 is electrically connected to the emitter (E) of the IGBT. The current detection module 201 is configured to send a first trigger signal to the boost module when it detects that the current output from the emitter of the IGBT is greater than or equal to a preset current threshold. The control terminal of the boost module 202 is electrically connected to the output terminal of the current detection module 201, and the output terminal of the boost module 202 is electrically connected to the protection terminal of the drive module. The boost module is configured to increase the voltage at the protection terminal of the drive module when it receives the first trigger signal. The drive terminal of the drive module is electrically connected to the gate of the IGBT. The drive module is configured to output a first turn-off signal through the drive terminal to turn off the IGBT for a first preset duration when the voltage at the protection terminal rises to a preset voltage threshold. The first preset duration is t2.

[0055] In this embodiment, when an IGBT experiences an overcurrent fault, the IGBT is deactivated by triggering the `desat` function of the Gate driver module. The duration of the IGBT deactivation can be controlled to be a first preset duration, t2. Because t2 is much longer than t1, the IGBT deactivation duration in this embodiment is relatively long. Even if the IGBT overcurrent is large, the current can be reduced within the first preset duration of IGBT deactivation, without affecting the safety of the IGBT or the efficiency of the motor controller. Furthermore, the preset current threshold can be set to any value according to actual conditions; this embodiment does not impose specific limitations on this.

[0056] In one possible implementation, the current detection module includes a current detection unit and a first trigger signal generation unit. The current detection unit is electrically connected to the emitter of the IGBT and is configured to generate a corresponding voltage signal based on the current signal output from the emitter of the IGBT.

[0057] The first trigger signal generation unit is electrically connected to the current detection unit to receive the voltage signal output by the current detection unit. The first trigger signal generation unit is configured to send a first trigger signal to the boost module when the voltage signal is greater than a preset reference voltage. Furthermore, when the current signal is greater than or equal to a preset current threshold, the voltage signal is greater than or equal to the reference voltage.

[0058] In one possible implementation, the current detection unit is a Hall sensor, and the first trigger signal generation unit is a comparator.

[0059] For ease of understanding, this application also provides a schematic diagram of the structure of a current detection module.

[0060] See Figure 3 This is a schematic diagram of the structure of a current detection module provided in an embodiment of this application. Figure 3 As shown, the current detection module 201 includes a Hall sensor (Hall) and a comparator C1. The detection terminal of the Hall sensor (Hall) is electrically connected to the emitter of the IGBT. The Hall sensor (Hall) detects the current signal output by the IGBT and converts the current signal into a voltage signal. When the current signal is greater than or equal to a preset current threshold, the voltage signal is greater than or equal to a reference voltage. The positive input terminal of the comparator C1 is connected to the reference voltage (Ref), and the negative input terminal of the comparator C1 is electrically connected to the output terminal of the Hall sensor (Hall). The negative input terminal of the comparator C1 receives the voltage signal output by the output terminal of the Hall sensor (Hall). When the voltage signal at the negative input terminal is greater than or equal to the reference voltage, the comparator C1 sends a low-level signal as a first trigger signal to the boost module. The detection terminal of the Hall sensor (Hall) is the input terminal of the current detection module 201, and the output terminal of the comparator C1 is the output terminal of the current detection module 201.

[0061] In one possible implementation, the boost module includes a first switching unit and a second switching unit, with the control terminal of the first switching unit electrically connected to the current detection module.

[0062] See Figure 4 This is a schematic diagram of a boost module provided in an embodiment of this application. Figure 4 As shown, in one possible implementation, the boost module 202 includes a first switching unit 401 and a second switching unit 402. The control terminal of the first switching unit 401 is electrically connected to the current detection module, the input terminal of the first switching unit 401 is used to connect to a first power supply, and the output terminal of the first switching unit 401 is electrically connected to the control terminal of the second switching unit 402. The second switching unit 402 is connected in series with the protection terminal of the drive module. The first switching unit 401 is configured to control the second switching unit 402 to disconnect when a first trigger signal is received, thereby causing the protection terminal of the drive module to float. During operation, the protection terminal of the drive module continuously outputs current. When the protection terminal of the drive module is floated, charge accumulates at the protection terminal, resulting in an increase in the voltage at the protection terminal.

[0063] Among them, the control terminal of the first switching unit 401 is the control terminal of the boost module.

[0064] In one possible implementation, the first switching unit is an NMOS transistor, and the second switching unit is an optocoupler.

[0065] For ease of understanding, this application also provides a schematic diagram of another boost module.

[0066] See Figure 5 This is a schematic diagram of another boost module provided in an embodiment of this application. Figure 5 As shown, the first switching unit is an NMOS transistor Q1, the second switching unit is an optocoupler opt, and the boost module also includes a first resistor R1, which is used for current limiting to ensure the normal operation of the optocoupler. The first end of the first resistor is used to connect to the first power supply. The gate of the NMOS transistor is electrically connected to the output terminal of the current detection module, the drain of the NMOS transistor is electrically connected to the second end of the first resistor, the first input terminal of the optocoupler is electrically connected to the source of the NMOS transistor, and the optocoupler is connected in series to the protection terminal of the drive module. The gate of the NMOS transistor is the control terminal of the first switching unit, the drain of the NMOS transistor is the input terminal of the first switching unit, and the source of the NMOS transistor is the output terminal of the first switching unit.

[0067] As mentioned above, the comparator sends a low-level signal to the boost module as the first trigger signal. After the gate of the NMOS transistor in the boost module receives the low-level signal, the connection between the source and drain is broken. At this time, the light-emitting diode in the optocoupler stops emitting light because it does not receive power. The phototransistor is disconnected because it does not receive light. Since the phototransistor is connected in series with the protection terminal of the driver module, the protection terminal of the driver module is left floating after the phototransistor is disconnected. Because the protection terminal of the driver module will continue to output current, when the protection terminal of the driver module is left floating, charge accumulates at the protection terminal of the driver module, thereby causing the voltage at the protection terminal to rise.

[0068] Of course, in practical applications, the first switching unit 401 can also be any other device with switching function, such as a gate turn-off transistor or a power field-effect transistor, etc. This application embodiment does not impose specific limitations on this.

[0069] In addition, the first switching unit can also be a capacitive isolator or a magnetic isolator, and the second switching unit can also be a transistor. This application does not impose specific limitations on these aspects.

[0070] For ease of understanding, this application also provides a schematic diagram of another boost module.

[0071] See Figure 6 This is a schematic diagram of another boost module provided in an embodiment of this application. Figure 6 As shown in Figure a, the first switching unit is a capacitive isolator 601, the second switching unit is an NPN transistor Q2, and the boost module also includes a second capacitor C2 and a fifth resistor R5. The capacitive isolator in this embodiment can match different power supply voltages, namely a first power supply (5V) and a second power supply (15V). It is understood that the first and second power supplies do not occur simultaneously, and the magnitude of the power supply voltage depends on the voltage of the external circuit. When the comparator sends a low-level signal to the boost module, the capacitive isolator generates and outputs a corresponding new low-level signal based on the low-level signal and the power supply voltage. When the NPN transistor receives the new low-level signal, it disconnects the connection between the emitter and collector. Because the NPN transistor is connected in series at the protection terminal of the drive module, after the emitter and collector are disconnected, the protection terminal of the drive module is left floating, resulting in an increase in the voltage at the protection terminal.

[0072] In addition, such as Figure 6As shown in b, the first switching unit is a magnetic isolator 602, the second switching unit is an NPN transistor Q2, and the boost module also includes a second capacitor C2 and a fifth resistor R5. Similar to the capacitive isolator, the magnetic isolator in this embodiment can be matched to different power supply voltages. When the comparator sends a low-level signal to the boost module, the magnetic isolator generates and outputs a corresponding new low-level signal based on the low-level signal and the power supply voltage. When the NPN transistor receives the new low-level signal, it disconnects the connection between the emitter and collector. Because the NPN transistor is connected in series at the protection terminal of the drive module, the protection terminal of the drive module is left floating after the emitter and collector are disconnected, resulting in an increase in the voltage at the protection terminal.

[0073] In the embodiments of this application, the first power supply is 5V and the second power supply is 15V. This is only an exemplary illustration and should not be regarded as a limitation on the scope of protection of this application.

[0074] In one possible implementation, the IGBT protection circuit also includes a delay module and a level conversion module.

[0075] See Figure 7 This is a schematic diagram of another IGBT protection circuit provided in an embodiment of this application. Figure 7 As shown, the IGBT protection circuit in Figure 2 The circuit shown also includes a delay module 701 and a level conversion module Transceiver.

[0076] like Figure 7 As shown, the input terminal of the delay module is electrically connected to the output terminal of the current detection module. The delay module is configured to output a first trigger signal after a preset delay. The trigger terminal of the level conversion module is electrically connected to the output terminal of the delay module, and the output terminal of the level conversion module is electrically connected to the input terminal of the drive module. The level conversion module is configured to output a second trigger signal to the drive module when it receives the first trigger signal. The drive module is configured to output a second turn-off signal through its drive terminal to turn off the IGBT for a second preset time after receiving the second trigger signal. The CE terminal of the level conversion module is its trigger terminal.

[0077] Understandably, if the level conversion module outputs a second trigger signal to the driver module before the driver module triggers the desat function, the driver module's desat function may fail to trigger. Therefore, a delay module is needed to ensure that the desat function triggers first. Furthermore, when the level conversion module has not received the first trigger signal, it can still normally output control signals to the driver module, thus ensuring the driver module functions properly.

[0078] Furthermore, the delay module enables the level conversion module to receive the first trigger signal output by the current detection module. Even if the desat function fails to trigger, the first trigger signal can control the level conversion module to output a second trigger signal to the drive module. Upon receiving the second trigger signal, the drive module outputs a second turn-off signal through the drive terminal g to turn off the IGBT for a second preset duration. Although the second preset duration is short, it still maximizes the safety of the IGBT. In one possible implementation, the second preset duration is t1.

[0079] In this embodiment, the delay module is an RC delay circuit. For ease of understanding, this embodiment also provides a schematic diagram of the delay module.

[0080] See Figure 8 This is a schematic diagram of the structure of a delay module provided in an embodiment of this application. Figure 8 As shown, the delay module 701 includes a second resistor R2 and a first capacitor C1. The first end of the second resistor is electrically connected to the output end of the current detection module; the first end of the first capacitor is electrically connected to the second end of the second resistor, and the second end of the first capacitor is grounded; wherein, the first end of the second resistor is the input end of the delay module, and the node between the second end of the second resistor and the first end of the first capacitor is the output end of the delay module.

[0081] In the embodiments of this application, the delay module includes a resistor and a capacitor. However, in practical applications, the delay module may also include multiple resistors and multiple capacitors. The embodiments of this application do not impose specific limitations on this.

[0082] In addition, the overcurrent protection sub-circuit in this embodiment further includes a second capacitor, a third resistor, and a diode. The first terminal of the second capacitor is electrically connected to the desat terminal of the drive module, and the second terminal of the second capacitor is grounded. The first terminal of the third resistor is electrically connected to both the first terminal of the second capacitor and the desat terminal of the drive module through a channel. The input terminal of the diode is electrically connected to the second terminal of the third resistor, and the output terminal of the diode is electrically connected to the collector of the IGBT. It can be understood that the second capacitor, the third resistor, and the diode are added between the desat terminal of the drive module and the collector of the IGBT to ensure circuit stability.

[0083] In addition, the overcurrent protection sub-circuit in this embodiment further includes a fourth resistor. The first end of the fourth resistor is electrically connected to the drive terminal g of the drive module, and the second end of the fourth resistor is electrically connected to the gate of the IGBT. The fourth resistor ensures circuit stability, and its functions include, but are not limited to, current limiting, controlling the charging and discharging speed of the IGBT gate, and preventing gate oscillation. Furthermore, the normal turn-off time t1 of the IGBT can be adjusted by adjusting the resistance value of the fourth resistor.

[0084] Corresponding to the above embodiments, this application also provides another IGBT protection circuit.

[0085] See Figure 9 This is a schematic diagram of another IGBT protection circuit provided in an embodiment of this application. Figure 9 As shown, when an IGBT experiences an overcurrent fault, the current detection module outputs a first trigger signal to characterize the IGBT overcurrent. Upon receiving this first trigger signal, the boost module increases the voltage at the protection terminal of the drive module, thereby triggering the desat function of the drive module. The drive module then outputs a first turn-off signal to turn off the IGBT for a first preset time. It can be understood that a relatively long first preset time ensures that even with a large IGBT overcurrent, the current can decrease within the first preset time of IGBT turn-off, without affecting the IGBT's safety or the efficiency of the motor controller.

[0086] In addition, when an IGBT experiences a short circuit fault, the voltage at the desat terminal of the gate driver increases significantly, triggering the desat function. The desat function causes the gate driver to turn off the IGBT through the g terminal, and the turn-off time t2 is several times longer than the normal turn-off time t1 of the IGBT, thereby reducing the value of di / dt. The voltage spike U will also decrease accordingly, thus protecting the IGBT from damage due to overvoltage at the CE terminal.

[0087] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, the simultaneous existence of A and B, or the existence of B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0088] Those skilled in the art will recognize that the units and algorithm steps described in the embodiments disclosed herein can be implemented using electronic hardware, computer software, or a combination of electronic hardware and software. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0089] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0090] In the several embodiments provided in this application, any function, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0091] The same or similar parts between the various embodiments in this specification can be referred to mutually. In particular, the device embodiments and terminal embodiments are basically similar to the method embodiments, so the description is relatively simple, and the relevant parts can be referred to the description in the method embodiments.

Claims

1. An IGBT protection circuit, characterized in that, It includes a current detection module, a boost module, and a drive module, wherein the drive module has a protection terminal and a drive terminal: wherein, The input terminal of the current detection module is electrically connected to the emitter of the IGBT. The current detection module is configured to send a first trigger signal to the boost module when it detects that the current output by the emitter of the IGBT is greater than or equal to a preset current threshold. The control terminal of the boost module is electrically connected to the output terminal of the current detection module, and the boost module is electrically connected to the protection terminal of the drive module. The boost module is configured to increase the voltage at the protection terminal of the drive module when the first trigger signal is received. The driving terminal of the driving module is electrically connected to the gate of the IGBT. The driving module is configured to output a first turn-off signal through the driving terminal to turn off the IGBT for a first preset duration when the voltage of the protection terminal rises to a preset voltage threshold.

2. The circuit according to claim 1, characterized in that, The current detection module includes a current detection unit and a first trigger signal generation unit; wherein... The current detection unit is electrically connected to the emitter of the IGBT, and the current detection unit is configured to generate a corresponding voltage signal based on the current signal output from the emitter of the IGBT. The first trigger signal generation unit is electrically connected to the current detection unit to receive the voltage signal output by the current detection unit. The first trigger signal generation unit is configured to send a first trigger signal to the boost module when the voltage signal is greater than a preset reference voltage.

3. The circuit according to claim 2, characterized in that, The current detection unit includes a Hall sensor; the first trigger signal generation unit includes a comparator.

4. The circuit according to claim 1, characterized in that, The boost module includes: a first switching unit and a second switching unit, wherein the control terminal of the first switching unit is electrically connected to the current detection module, and the output terminal of the first switching unit is electrically connected to the control terminal of the second switching unit; The second switch unit is connected in series with the protection terminal of the drive module; The first switching unit is configured to control the second switching unit to disconnect when the first trigger signal is received, so that the protection terminal of the drive module is left floating.

5. The circuit according to claim 4, characterized in that, The first switching unit includes an NMOS transistor, a capacitive isolator, or a magnetic isolator; The second switching unit includes an optocoupler or a transistor.

6. The circuit according to claim 1, characterized in that, The circuit also includes: The delay module has its input terminal electrically connected to the output terminal of the current detection module, and is configured to output the first trigger signal after a preset delay time. A level conversion module, wherein the trigger terminal of the level conversion module is electrically connected to the output terminal of the delay module, and the output terminal of the level conversion module is electrically connected to the input terminal of the drive module; The level conversion module is configured to output a second trigger signal to the driving module when the trigger terminal of the level conversion module receives the first trigger signal; The drive module is configured to output a second shutdown signal through the drive terminal to shut down the IGBT for a second preset duration after receiving the second trigger signal.

7. The circuit according to claim 6, characterized in that, The delay module includes an RC delay circuit.

8. A motor control circuit, characterized in that, include: The IGBT protection circuit according to any one of claims 1-7.

9. A vehicle, characterized in that, include: The motor control circuit according to claim 8.

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