A protection circuit, method, inverter and vehicle

Abstract

The application provides a protection circuit, a method, an inverter and a vehicle, and relates to the technical field of power switches. In the case that any power switch device in the protection end works abnormally, the control module controls the switch module to be turned off to disconnect the control circuit of the power switch device, so that the power switch devices other than the power switch device that is broken down and short-circuited are not turned off. The short-circuit current of the power switch device that is broken down and short-circuited generates a magnetic field, and the other power switch devices are turned on under the action of the magnetic field coupling. Since the other power switch devices are shunted with the power switch device that is broken down and short-circuited, the short-circuit current of the power switch device that is broken down and short-circuited can be reduced, and the risk of explosion or fire of the power switch device that is broken down and short-circuited due to the short-circuit current causing the power switch device to be broken down can be reduced.

Description

Technical Field

[0001] This application relates to the field of power switch technology, and more particularly to a protection circuit, method, inverter, and vehicle. Background Technology

[0002] A power switch module includes multiple power switch devices connected in parallel. In related technologies, if one of the power switch devices in the power switch module breaks down and is damaged, the control terminal of the power switch module is pulled low in order to shut down the abnormal power switch module.

[0003] However, while other power switching devices are turned off, the damaged power switching device short-circuit and conducts. The excessive short-circuit current passing through the damaged power switching device causes it to explode or catch fire. Summary of the Invention

[0004] This application provides a protection circuit, method, inverter, and vehicle to solve the problem in the related art where a short circuit occurs in a damaged power switching device, causing excessive short-circuit current to pass through the damaged power switching device, leading to the explosion or fire of the damaged power switching device.

[0005] In a first aspect, embodiments of this application provide a protection circuit, including: a driving terminal, a terminal to be protected, a control module, and a switching module;

[0006] The driving terminal is used to input driving signals;

[0007] The terminal to be protected is used to connect at least two power switching devices in parallel;

[0008] The first terminal of the switch module is electrically connected to the drive terminal;

[0009] The first terminal of the control module is electrically connected to the second terminal of the switch module, and the second terminal of the control module and the third terminal of the switch module are electrically connected to the terminal to be protected.

[0010] The control module is used to control the switch module to shut down and disconnect the control circuit of the power switch device in the event of any abnormal operation of the power switch device in the protected terminal.

[0011] Optionally, the driving terminal is used to electrically connect to the driving chip of the power switching device; the control module is used to disconnect the control circuit of the driving chip controlling the power switching device.

[0012] Optionally, the control module includes a comparison submodule and a control submodule; the comparison submodule is electrically connected to the control submodule, and the comparison submodule is used to be electrically connected to the end to be protected; the control submodule is electrically connected to the switch module; the comparison submodule is used to determine whether an abnormality has occurred at the end to be protected; the control submodule is used to send a drive signal to the switch module to turn off the switch module when an abnormality has occurred at the end to be protected.

[0013] Optionally, the comparison submodule includes an operational amplifier; the first input terminal of the operational amplifier is disposed between the driving terminal and the terminal to be protected, the second input terminal of the operational amplifier is connected to a potential reference point, and the output terminal of the operational amplifier is electrically connected to the first input terminal of the control submodule.

[0014] Optionally, the protection circuit further includes a first diode; the first diode is disposed between the driving end and the end to be protected, and the first input end and the second input end of the comparison submodule are respectively disposed at the two ends of the first diode.

[0015] Optionally, the comparison submodule further includes a voltage acquisition unit; the voltage acquisition unit is disposed between the operational amplifier and the driver terminal.

[0016] Optionally, the voltage acquisition unit includes a voltage amplifier, with a first input terminal of the voltage amplifier disposed at the negative terminal of the first diode and a second input terminal of the voltage amplifier disposed at the positive terminal of the first diode; the first input terminal and the second input terminal of the voltage amplifier respectively constitute the first input terminal and the second input terminal of the comparison submodule.

[0017] Optionally, the operational amplifier includes a first operational amplifier; the first input terminal of the first operational amplifier is electrically connected to the output terminal of the voltage amplifier, the second input terminal of the first operational amplifier is used to acquire a reference voltage signal, and the output terminal of the first operational amplifier is electrically connected to the first input terminal of the control submodule.

[0018] Optionally, the voltage acquisition unit further includes a second resistor and a third resistor: the second resistor is disposed between the positive terminal of the first diode and the first input terminal of the voltage amplifier, and the third resistor is disposed between the negative terminal of the first diode and the second input terminal of the voltage amplifier.

[0019] Optionally, the voltage acquisition unit further includes: a first capacitor, the first end of which is electrically connected to the second end of the second resistor and the first input terminal of the voltage amplifier, and the second end of the first capacitor is grounded; and / or, a second capacitor, the first end of which is electrically connected to the first input terminal of the voltage amplifier, and the second end of the second capacitor is grounded.

[0020] Optionally, the voltage acquisition unit further includes a fourth resistor; the first end of the fourth resistor is electrically connected to the output terminal of the voltage amplifier, and the second end of the fourth resistor is electrically connected to the second input terminal of the voltage amplifier.

[0021] Optionally, the voltage acquisition unit further includes a clamping unit; the first end of the clamping unit is electrically connected to the first input end of the voltage amplifier, and the second end of the clamping unit is grounded.

[0022] Optionally, the operational amplifier includes a second operational amplifier; the first input terminal of the second operational amplifier is disposed between the first diode and the driving terminal.

[0023] Optionally, the comparison submodule further includes an eighth resistor and a fifth resistor; the eighth resistor and the fifth resistor are connected in series; the series branch formed by the eighth resistor and the fifth resistor is connected in parallel with the power switching device.

[0024] Optionally, the operational amplifier includes a third operational amplifier, the first input terminal of which is electrically connected between the fifth resistor and the eighth resistor.

[0025] Optionally, the control submodule includes a NOT gate; the input terminal of the NOT gate is electrically connected to the output terminal of the comparison submodule.

[0026] Optionally, the control submodule further includes an AND gate device; the first input terminal of the AND gate device is electrically connected to the output terminal of the NOT gate device, the second input terminal of the AND gate device is electrically connected to the second terminal of the switch module, and the output terminal of the AND gate device is electrically connected to the control terminal of the switch module.

[0027] Optionally, the switching module includes a switching device; the second end of the switching device is electrically connected to the input end of the control module and the control end of the power switching device, respectively, and the control end of the switching device is electrically connected to the output end of the control module.

[0028] Optionally, the switching module further includes a sixth resistor, the first end of which is electrically connected to the driving end, and the second end of which is electrically connected to the first end of the switching device.

[0029] Optionally, the switching module further includes a body diode; the positive terminal of the body diode is electrically connected to the driving terminal, and the negative terminal of the body diode is electrically connected to the third terminal of the control module and the control terminal of the power switching device, respectively.

[0030] Optionally, the protection circuit further includes a first protection module; a first terminal of the first protection module is electrically connected to the driving terminal, and a second terminal of the first protection module is grounded.

[0031] Optionally, the protection circuit further includes a second protection module; the first terminal of the second protection module is electrically connected to the control terminal of the power switching device, and the second terminal of the second protection module is grounded.

[0032] Optionally, the protection circuit further includes a third protection module; the first end of the third protection module is electrically connected to the driving end, and the second end of the third protection module is electrically connected to the first end of the power switching device.

[0033] Secondly, embodiments of this application also provide a protection method applied to the protection circuit as described in the first aspect, the method comprising:

[0034] Obtain the operating status of at least two power switching devices connected in parallel;

[0035] If any of the power switching devices malfunctions, disconnect the control circuit of the power switching device.

[0036] Optionally, disconnecting the control circuit of the power switching device includes: disconnecting the control circuit for turning off the power switching device.

[0037] Optionally, disconnecting the control circuit of the power switching device when any of the power switching devices is in an abnormal operating state includes: disconnecting the control circuit when the power switching device is short-circuited.

[0038] Thirdly, embodiments of this application also provide an inverter, including a multi-phase bridge arm, a power switch module, and a protection circuit as described in the first aspect, wherein the power switch module is connected to the protection circuit, and the power switch module includes at least two power switch devices connected in parallel.

[0039] Optionally, the inverter further includes a driver chip, which is connected to the power switch module through the protection circuit.

[0040] Fourthly, embodiments of this application also provide a vehicle including the protection circuit described in the first aspect, or including the inverter described in the third aspect.

[0041] In summary, in this embodiment, since the driving end is used to input the driving signal, the end to be protected is connected to at least two power switching devices in parallel. The first end of the switching module is electrically connected to the driving end, the first end of the control module is electrically connected to the second end of the switching module, and the second end of the control module and the third end of the switching module are electrically connected to the end to be protected. When any power switching device in the end to be protected malfunctions, the control module controls the switching module to turn off, thereby disconnecting the control circuit of the power switching device. This prevents other power switching devices in the power switching module from turning off, except for the power switching device that has broken down and short-circuited. The short-circuit current of the power switching device that has broken down and short-circuited generates a magnetic field, and other power switching devices are turned on under the coupling effect of this magnetic field. Since the other power switching devices are connected in parallel with the power switching device that has broken down and short-circuited, the current is shunted, thus reducing the short-circuit current passing through the power switching device that has broken down and short-circuited, and reducing the risk of the power switching device that has broken down and short-circuited due to the short-circuit current exploding or catching fire.

[0042] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0044] Figure 1 This is a schematic diagram of a protection circuit provided in an embodiment of this application;

[0045] Figure 2 This is a schematic diagram of a specific structure of a protection circuit provided in an embodiment of this application;

[0046] Figure 3 A schematic diagram of another protection circuit provided in this application embodiment;

[0047] Figure 4 A schematic diagram of the specific structure of another protection circuit provided in the embodiments of this application;

[0048] Figure 5 A schematic diagram illustrating the specific structure of yet another protection circuit provided in an embodiment of this application;

[0049] Figure 6 This is a schematic diagram illustrating the specific structure of another protection circuit provided in the embodiments of this application;

[0050] Figure 7 A schematic diagram illustrating the structure of yet another protection circuit provided in this application embodiment;

[0051] Figure 8 A schematic diagram of a protection process for a power switch module provided in an embodiment of this application;

[0052] Figure 9 This is a schematic diagram of an inverter provided in an embodiment of this application.

[0053] Figure label:

[0054] 10-Control Module; 11-Comparator Submodule; 12-Control Submodule; 20-Switch Module; 30-Power Switch Module; 40-Driver Chip; R1-First Resistor; R2-Second Resistor; R3-Third Resistor; R4-Fourth Resistor; R5-Fifth Resistor; R6-Sixth Resistor; R7-Seventh Resistor; R8-Eighth Resistor; Q1-Switch Device; C1-First Capacitor; C2-Second Capacitor; C3-Third Capacitor; C4-Fourth Capacitor; D1-First Diode; D2-Second Diode; D3-Third Diode; D4-Fourth Diode; D5-Fifth Diode; D6-Sixth Diode; D7-Seventh Diode; D8-Body Diode; P1-Voltage Amplifier; P2-First Operational Amplifier; P3-Second Operational Amplifier; P4-Third Operational Amplifier; U1-AND Gate Device; U2-NOT Gate Device. Detailed Implementation

[0055] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0056] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0057] Reference Figure 1This application provides a protection circuit, including: a driving terminal, a terminal to be protected, a control module 10, and a switching module 20; the driving terminal is used to input a driving signal; the terminal to be protected is used to connect at least two power switching devices in parallel; a first terminal of the switching module 20 is electrically connected to the driving terminal; a first terminal of the control module 10 is electrically connected to a second terminal of the switching module 20, and the second terminal of the control module 10 and the third terminal of the switching module 20 are electrically connected to the terminal to be protected; the control module 10 is used to control the switching module 20 to turn off, thereby disconnecting the control circuit of the power switching device, in the event of an abnormal operation of any of the power switching devices in the terminal to be protected.

[0058] In this embodiment, the driving end is used to input the driving signal, and the end to be protected is connected to at least two power switching devices in parallel. The first end of the switching module 20 is electrically connected to the driving end, the first end of the control module 10 is electrically connected to the second end of the switching module 20, and the second end of the control module 10 and the third end of the switching module 20 are electrically connected to the end to be protected. When any power switching device in the end to be protected malfunctions, the control module 10 controls the switching module 20 to turn off, thereby disconnecting the control circuit of the power switching device. This prevents other power switching devices in the power switching module 30 from turning off, except for the power switching device that has broken down and short-circuited. The short-circuit current of the power switching device that has broken down and short-circuited generates a magnetic field, and other power switching devices are turned on under the coupling effect of this magnetic field. Since other power switching devices are connected in parallel with the power switching device that has broken down and short-circuited and shunt the current, the short-circuit current passing through the power switching device that has broken down and short-circuited can be reduced, thereby reducing the risk of the power switching device that has broken down and damaged due to the short-circuit current exploding or catching fire.

[0059] In some embodiments, the control module 10 is electrically connected to the power switch module 30 and controls the switch module 20 to turn off in the event of a short circuit in the power switch device in the power switch module 30; the switch module 20 is electrically connected to the power switch module 30 and the driver chip 40 of the power switch module 30 respectively, and disconnects the control circuit of the driver chip 40 to turn off the power switch module 30 when the switch module 20 is turned off; wherein, the power switch module 30 includes a plurality of power switch devices connected in parallel.

[0060] It should be noted that the driver chip 40 is used to control the on and off of the power switch module 30.

[0061] In some embodiments, the first terminal of the power switching device is used to connect to the positive terminal of the power supply, and the second terminal of the power switching device is grounded.

[0062] It should be noted that the first terminal of each power switch device is connected to the first terminal of the power switch module 30, the second terminal of each power switch device is connected to the second terminal of the power switch module 30, and the control terminal of each power switch device is connected to the control terminal of the power switch module 30.

[0063] In some embodiments, the power switching devices include insulated-gate bipolar transistors (IGBTs), silicon carbide (SiC) power switching devices, etc.

[0064] In this embodiment, when a power switching device in the power switching module 30 experiences a short circuit, the control module 10 controls the switch module 20 to turn off. Furthermore, when the switch module 20 is off, the drive chip 40 disconnects the control circuit of the power switching module 30 to prevent other power switching devices in the power switching module 30 from turning off. The short-circuit current of the short-circuited power switching device generates a magnetic field, which causes other power switching devices to conduct under the coupling effect of this magnetic field. Since the other power switching devices are connected in parallel with the short-circuited power switching device and shunt the current, the short-circuit current passing through the short-circuited power switching device can be reduced, thus lowering the risk of the damaged power switching device exploding or catching fire due to the short-circuit current.

[0065] Optionally, refer to Figure 2 In some embodiments, the control module 10 includes a comparison submodule 11 and a control submodule 12; the comparison submodule 11 is electrically connected to the control submodule 12, and the comparison submodule 11 is used to be electrically connected to the end to be protected; the control submodule 12 is electrically connected to the switch module 20; the comparison submodule 11 is used to determine whether the end to be protected has an abnormality; the control submodule 12 is used to send a drive signal to the switch module 20 to turn off the switch module 20 when the end to be protected has an abnormality.

[0066] In this embodiment, the comparison submodule 11 determines whether an abnormality has occurred at the end to be protected. If an abnormality occurs at the end to be protected, the control submodule 12 sends a drive signal to the switch module 20 to turn off the switch module 20, thereby disconnecting the control circuit of the drive chip 40 to turn off the power switch module 30.

[0067] In some embodiments, the comparison submodule 11 includes an operational amplifier; the first input terminal of the operational amplifier is disposed between the driving terminal and the protected terminal, the second input terminal of the operational amplifier is connected to a potential reference point, and the output terminal of the operational amplifier is electrically connected to the first input terminal of the control submodule 12.

[0068] Specifically, the first input terminal of the operational amplifier is the non-inverting input terminal of the operational amplifier, and the second input terminal of the operational amplifier is the inverting input terminal of the operational amplifier.

[0069] In some embodiments, the protection circuit further includes a first diode D1; the first diode D1 is disposed between the driving end and the end to be protected, and the first input end and the second input end of the comparison submodule 11 are respectively disposed at the two ends of the first diode D1.

[0070] In some embodiments, the comparison submodule 11 further includes a voltage acquisition unit; the voltage acquisition unit is disposed between the operational amplifier and the driving terminal.

[0071] In some embodiments, the voltage acquisition unit includes a voltage amplifier P1, the first input terminal of the voltage amplifier P1 is disposed at the negative terminal of the first diode D1, and the second input terminal of the voltage amplifier P1 is disposed at the positive terminal of the first diode D1; the first input terminal and the second input terminal of the voltage amplifier P1 respectively constitute the first input terminal and the second input terminal of the comparison submodule 11.

[0072] In some embodiments, the operational amplifier includes a first operational amplifier P2; a first input terminal of the first operational amplifier P2 is electrically connected to the output terminal of the voltage amplifier P1, a second input terminal of the first operational amplifier P2 is used to acquire a reference voltage signal, and the output terminal of the first operational amplifier P2 is electrically connected to the first input terminal of the control submodule 12.

[0073] Specifically, the first input terminal of the first operational amplifier P2 is the non-inverting input terminal of the first operational amplifier P2, and the second input terminal of the first operational amplifier P2 is the inverting input terminal of the first operational amplifier P2.

[0074] In some embodiments, the voltage acquisition unit further includes a second resistor R2 and a third resistor R3: the second resistor R2 is disposed between the positive terminal of the first diode D1 and the first input terminal of the voltage amplifier P1, and the third resistor R3 is disposed between the negative terminal of the first diode D1 and the second input terminal of the voltage amplifier P1.

[0075] In some embodiments, the voltage acquisition unit further includes: a first capacitor C1, the first end of which is electrically connected to the second end of the second resistor R2 and the first input terminal of the voltage amplifier P1, and the second end of the first capacitor C1 is grounded; and / or, a second capacitor C2, the first end of which is electrically connected to the first input terminal of the voltage amplifier P1, and the second end of the second capacitor C2 is grounded.

[0076] In some embodiments, the operational amplifier 11 includes a second operational amplifier P3; the first input terminal of the second operational amplifier P3 is disposed between the first diode D1 and the driving terminal. Specifically, the first input terminal of the second operational amplifier P3 is the non-inverting input terminal of the second operational amplifier P3, and the second input terminal of the second operational amplifier P3 is the inverting input terminal of the second operational amplifier P3.

[0077] In some embodiments, the operational amplifier includes a third operational amplifier P4, the first input terminal of which is electrically connected between the fifth resistor R5 and the eighth resistor R8.

[0078] Specifically, the first input terminal of the third operational amplifier P4 is the non-inverting input terminal of the third operational amplifier P4, and the second input terminal of the third operational amplifier P4 is the inverting input terminal of the third operational amplifier P4.

[0079] Optionally, refer to Figure 3 In some embodiments, the protection circuit further includes a first resistor R1, a first diode D1, and a second diode D2; the comparison submodule 11 includes a voltage amplifier P1, a first operational amplifier P2, a second resistor R2, and a third resistor R3; the first end of the first resistor R1 is electrically connected to the desaturation protection input terminal of the driver chip 40, and the second end of the first resistor R1 is electrically connected to the first end of the third resistor R3 and the positive terminal of the first diode D1; the negative terminal of the first diode D1 is electrically connected to the first end of the second resistor R2 and the positive terminal of the second diode D2; the negative terminal of the second diode D2 is electrically connected to the first terminal of the power switch module 30; the first input terminal of the voltage amplifier P1 is electrically connected to the second end of the second resistor R2, the second input terminal of the voltage amplifier P1 is electrically connected to the second end of the third resistor R3, and the output terminal of the voltage amplifier P1 is electrically connected to the first input terminal of the first operational amplifier P2; the second input terminal of the first operational amplifier P2 is used to acquire a reference voltage signal, and the output terminal of the first operational amplifier P2 is electrically connected to the first input terminal of the control submodule 12.

[0080] It should be noted that the first resistor R1 is a current-limiting resistor, the first diode D1 and the second diode D2 are used for overvoltage protection, and the first diode D1 and the second diode D2 are redundant; the second resistor R2 is the input resistance of the first input terminal of the voltage amplifier P1, and the third resistor R3 is the input resistance of the second input terminal of the voltage amplifier P1.

[0081] In some embodiments, the desaturation protection input of the driver chip 40 is used to output the pulse width modulation (PWM) signal to drive the power switch module 30.

[0082] In this embodiment, voltage amplifier P1 amplifies the voltage of the first diode D1, and first operational amplifier P2 compares the amplified voltage of the first diode D1 with a reference voltage. Since the voltage of the first diode D1 is positively correlated with the voltage between the first terminal and the second terminal of the power switch module 30, when the power switch device in the power switch module 30 breaks down and short-circuits, the voltage between the first terminal and the second terminal of the power switch module 30 decreases, causing the amplified voltage of the first diode D1 to be less than the reference voltage. Therefore, the first operational amplifier P2 outputs a low level.

[0083] Optionally, in some embodiments, the comparison submodule 11 further includes a fourth resistor R4; the first end of the fourth resistor R4 is electrically connected to the output terminal of the voltage amplifier P1, and the second end of the fourth resistor R4 is electrically connected to the second input terminal of the voltage amplifier P1.

[0084] In this embodiment, the fourth resistor R4 is the negative feedback resistor of the voltage amplifier P1.

[0085] Optionally, in some embodiments, the comparison submodule 11 further includes a first capacitor C1; the first end of the first capacitor C1 is electrically connected to the second end of the second resistor R2 and the first input end of the voltage amplifier P1, respectively, and the second end of the first capacitor C1 is grounded.

[0086] In this embodiment, the first capacitor C1 is the filter capacitor at the first input terminal of the voltage amplifier P1.

[0087] Optionally, in some embodiments, the comparison submodule 11 further includes a second capacitor C2; the first end of the second capacitor C2 is electrically connected to the first input terminal of the voltage amplifier P1, and the second end of the second capacitor C2 is grounded.

[0088] In this embodiment, the second capacitor C2 is the filter capacitor at the second input terminal of the voltage amplifier P1.

[0089] In some embodiments, the voltage acquisition unit further includes a clamping unit; the first end of the clamping unit is electrically connected to the first input end of the voltage amplifier P1, and the second end of the clamping unit is grounded.

[0090] Optionally, in some embodiments, the clamping unit includes a third diode D3 and a fourth diode D4; the cathode of the third diode D3 is electrically connected to the first input terminal of the voltage amplifier P1, and the anode of the third diode D3 is electrically connected to the anode of the fourth diode D4; the cathode of the fourth diode D4 is grounded.

[0091] In this embodiment, the third diode D3 and the fourth diode D4 together form a clamping circuit for clamping voltage protection of the second input terminal of the voltage amplifier P1.

[0092] Optionally, refer to Figure 4 In some embodiments, the protection circuit further includes a first resistor R1, a first diode D1, and a second diode D2; see reference. Figure 5 The comparison submodule 11 includes a second operational amplifier P3; the first end of the first resistor R1 is electrically connected to the first input terminal of the second operational amplifier P3 and the desaturation protection input terminal of the driver chip 40, respectively; the second end of the first resistor R1 is electrically connected to the positive terminal of the first diode D1; the negative terminal of the first diode D1 is electrically connected to the positive terminal of the second diode D2; the negative terminal of the second diode D2 is electrically connected to the first terminal of the power switch module 30; the second input terminal of the second operational amplifier P3 is used to acquire a reference voltage signal; and the output terminal of the second operational amplifier P3 is electrically connected to the first input terminal of the control submodule 12.

[0093] In this embodiment, the second operational amplifier P3 compares the voltage at the desaturation protection input of the driver chip 40 with a reference voltage. Since the voltage at the desaturation protection input of the driver chip 40 is positively correlated with the voltage between the first and second terminals of the power switch module 30, when a power switch device in the power switch module 30 short-circuits, the voltage between the first and second terminals of the power switch module 30 decreases, causing the voltage at the desaturation protection input of the driver chip 40 to be less than the reference voltage. Therefore, the second operational amplifier P3 outputs a low level.

[0094] In some embodiments, the comparison submodule 11 includes a third operational amplifier P4, an eighth resistor R8, and a fifth resistor R5; the eighth resistor R8 and the fifth resistor R5 are connected in series; the series branch formed by the eighth resistor R8 and the fifth resistor R5 is connected in parallel with the power switching device; the first input terminal of the third operational amplifier P4 is electrically connected between the fifth resistor R5 and the eighth resistor R8, the second input terminal of the third operational amplifier P4 is used to acquire a reference voltage signal, and the output terminal of the third operational amplifier P4 is electrically connected to the first input terminal of the control submodule 12.

[0095] Optionally, refer to Figure 7 In some embodiments, the comparison submodule 11 includes a third operational amplifier P4, an eighth resistor R8, and a plurality of fifth resistors R5; the eighth resistor R8 and the plurality of fifth resistors R5 are connected in series; the series branch formed by the eighth resistor R8 and the plurality of fifth resistors R5 is connected in parallel with the power switching device; the first input terminal of the third operational amplifier P4 is electrically connected between the fifth resistor R5 and the eighth resistor R8, the second input terminal of the third operational amplifier P4 is used to acquire a reference voltage signal, and the output terminal of the third operational amplifier P4 is electrically connected to the first input terminal of the control submodule 12.

[0096] In this embodiment, the third operational amplifier P4 is used to compare the voltage at the first input terminal of the third operational amplifier P4 with a reference voltage. The voltage at the first input terminal of the third operational amplifier P4 is the voltage of the eighth resistor R8. Since the voltage of the eighth resistor R8 is positively correlated with the voltage between the first terminal and the second terminal of the power switch module 30, when the power switch device in the power switch module 30 breaks down and short-circuits, the voltage between the first terminal and the second terminal of the power switch module 30 decreases, making the voltage of the eighth resistor R8 less than the reference voltage. Therefore, the third operational amplifier P4 outputs a low level.

[0097] For example, the comparator submodule 11 includes a third operational amplifier P4, an eighth resistor R8, and two fifth resistors R5. The first terminal of the first fifth resistor R5 is electrically connected to the first terminal of the power switch module 30, the second terminal of the first fifth resistor R5 is electrically connected to the first terminal of the second fifth resistor R5, the second terminal of the second fifth resistor R5 is electrically connected to the first terminal of the eighth resistor R8, and the second terminal of the eighth resistor R8 is electrically connected to the second terminal of the power switch module 30. The first input terminal of the third operational amplifier P4 is electrically connected to the second terminal of the second fifth resistor R5, the second input terminal of the third operational amplifier P4 is used to acquire a reference voltage signal, and the output terminal of the third operational amplifier P4 is electrically connected to the first input terminal of the control submodule 12. Optionally, in some embodiments, the control submodule 12 includes a NOT gate U2 and an AND gate U1; the input terminal of the NOT gate U2 is electrically connected to the output terminal of the comparison submodule 11, the output terminal of the NOT gate U2 is electrically connected to the first input terminal of the AND gate U1; the second input terminal of the AND gate U1 is electrically connected to the second terminal of the switch module 20, and the output terminal of the AND gate U1 is electrically connected to the control terminal of the switch module 20.

[0098] In this embodiment, when the output of the comparison submodule 11 is low, the NOT gate device U2 reverses the output level of the comparison submodule 11 and outputs a high level. At this time, when the second input terminal of the AND gate device U1 is low, the AND gate device U1 outputs a low level, and the switch module 20 is turned off to disconnect the control circuit of the driver chip 40 to turn off the power switch module 30.

[0099] It should be noted that the output level of the comparison submodule 11 is the output level of the first operational amplifier P2, the second operational amplifier P3, or the third operational amplifier P4; when the switch module 20 is turned on and the desaturation protection input of the driver chip 40 is at a low level, the second input of the AND gate device U1 is at a low level.

[0100] Optionally, refer to Figure 6 In some embodiments, the switching module 20 includes a sixth resistor R6 and a switching device Q1; the first end of the sixth resistor R6 is electrically connected to the drive output terminal of the drive chip 40, and the second end of the sixth resistor R6 is electrically connected to the first end of the switching device Q1; the second end of the switching device Q1 is electrically connected to the input terminal of the control module 10 and the control terminal of the power switch module 30, respectively, and the control terminal of the switching device Q1 is electrically connected to the output terminal of the control module 10.

[0101] In some embodiments, the switching module 20 further includes a body diode D8; the positive terminal of the body diode D8 is electrically connected to the driving terminal, and the negative terminal of the body diode D8 is electrically connected to the third terminal of the control module 10 and the control terminal of the power switching device, respectively.

[0102] Specifically, the body diode D8 is the body diode D8 (i.e., parasitic diode) of the switching device Q1. The positive terminal of the body diode D8 is electrically connected to the second terminal of the sixth resistor R6, and the negative terminal of the body diode D8 is electrically connected to the input terminal of the control module 10 and the control terminal of the power switch module 30, respectively. The input terminal of the control module 10 is the second input terminal of the AND gate device U1.

[0103] In some embodiments, the switching device Q1 is a MOS transistor (Metal-Oxide-Semiconductor Field-Effect Transistor).

[0104] In some embodiments, the active Miller clamping terminal of the driver chip 40 is electrically connected to the input terminal of the control module 10 and the control terminal of the power switch module 30, respectively; the ground terminal of the driver chip 40 is grounded.

[0105] In this embodiment, the sixth resistor R6 is a current-limiting resistor. When the output of the control module 10 is at a low level, the switching device Q1 is turned off to disconnect the control circuit of the driver chip 40 that turns off the power switching module 30.

[0106] It should be noted that the output level of control module 10 is the same as the output level of AND gate device U1.

[0107] In some embodiments, the protection circuit further includes a first protection module; a first terminal of the first protection module is electrically connected to the driving terminal, and a second terminal of the first protection module is grounded.

[0108] It should be noted that the driving end is electrically connected to the desaturation protection input terminal of the driving chip (40).

[0109] Optionally, in some embodiments, the first protection module includes a fifth diode D5; the negative terminal of the fifth diode D5 is electrically connected to the desaturation protection input terminal of the driving chip 40, and the positive terminal of the fifth diode D5 is grounded.

[0110] In this embodiment, the fifth diode D5 is a clamping diode.

[0111] Optionally, in some embodiments, the first protection module includes a third capacitor C3; the first end of the third capacitor C3 is electrically connected to the desaturation protection input terminal of the driver chip 40, and the second end of the third capacitor C3 is grounded.

[0112] In this embodiment, the third capacitor C3 is a filter capacitor.

[0113] In some embodiments, the protection circuit further includes a second protection module; the first terminal of the second protection module is electrically connected to the control terminal of the power switching device, and the second terminal of the second protection module is grounded.

[0114] Optionally, in some embodiments, the second protection module includes a seventh resistor R7; the first end of the seventh resistor R7 is electrically connected to the control terminal of the power switch module 30, and the second end of the seventh resistor R7 is grounded.

[0115] In this embodiment, the seventh resistor R7 is a pull-down resistor.

[0116] In some embodiments, the second protection module includes a clamping submodule; the first end of the clamping submodule is electrically connected to the control terminal of the power switching device, and the second end of the clamping submodule is grounded.

[0117] Optionally, in some embodiments, the clamping submodule includes a sixth diode D6 and a seventh diode D7; the negative terminal of the sixth diode D6 is electrically connected to the control terminal of the power switch module 30, and the positive terminal of the sixth diode D6 is electrically connected to the positive terminal of the seventh diode D7; the negative terminal of the seventh diode D7 is grounded.

[0118] In this embodiment, the sixth diode D6 and the seventh diode D7 are used together for clamping voltage protection.

[0119] Optionally, in some embodiments, the second protection module includes a fourth capacitor C4; the first end of the fourth capacitor C4 is electrically connected to the control terminal of the power switch module 30, and the second end of the fourth capacitor C4 is grounded.

[0120] In this embodiment, the fourth capacitor C4 is a filter capacitor.

[0121] In some embodiments, the protection circuit further includes a third protection module; a first terminal of the third protection module is electrically connected to the drive terminal, and a second terminal of the third protection module is electrically connected to the first terminal of the power switching device. It should be noted that the drive terminal is electrically connected to the desaturation protection input terminal of the drive chip 40.

[0122] In some embodiments, the third protection module includes a first resistor R1, a first diode D1, and a second diode D2; the first end of the first resistor R1 is electrically connected to the desaturation protection input terminal of the driver chip 40, and the second end of the first resistor R1 is electrically connected to the positive terminal of the first diode D1; the negative terminal of the first diode D1 is electrically connected to the positive terminal of the second diode D2; and the negative terminal of the second diode D2 is electrically connected to the first terminal of the power switching device.

[0123] In some embodiments, the protection circuit includes a control module 10 and a switch module 20; the control module 10 includes a comparison submodule 11 and a control submodule 12; the protection circuit also includes a first resistor R1, a first diode D1 and a second diode D2; the comparison submodule 11 includes a voltage amplifier P1, a first operational amplifier P2, a second resistor R2 and a third resistor R3;

[0124] The first end of the first resistor R1 is electrically connected to the desaturation protection input terminal of the driver chip 40. The second end of the first resistor R1 is electrically connected to the first end of the third resistor R3 and the positive terminal of the first diode D1. The negative terminal of the first diode D1 is electrically connected to the first end of the second resistor R2 and the positive terminal of the second diode D2. The negative terminal of the second diode D2 is electrically connected to the first terminal of the power switch module 30. The control submodule 12 includes a NOT gate device U2 and an AND gate device U1. The switch module 20 includes a sixth resistor R6 and a switch device Q1.

[0125] The first input terminal of voltage amplifier P1 is electrically connected to the second terminal of the second resistor R2, the second input terminal of voltage amplifier P1 is electrically connected to the second terminal of the third resistor R3, and the output terminal of voltage amplifier P1 is electrically connected to the first input terminal of the first operational amplifier P2. The second input terminal of the first operational amplifier P2 is used to obtain the reference voltage signal, and the output terminal of the first operational amplifier P2 is electrically connected to the input terminal of the NOT gate device U2.

[0126] The output terminal of NOT gate device U2 is electrically connected to the first input terminal of AND gate device U1; the second input terminal of AND gate device U1 is electrically connected to the second terminal of switch device Q1; and the output terminal of AND gate device U1 is electrically connected to the control terminal of switch device Q1.

[0127] The first end of the sixth resistor R6 is electrically connected to the drive output terminal of the driver chip 40, and the second end of the sixth resistor R6 is electrically connected to the first end of the switching device Q1; the second end of the switching device Q1 is electrically connected to the control terminal of the power switch module 30.

[0128] In this embodiment, voltage amplifier P1 amplifies the voltage of the first diode D1, and first operational amplifier P2 compares the amplified voltage of the first diode D1 with a reference voltage. Since the voltage of the first diode D1 is positively correlated with the voltage between the first and second terminals of the power switch module 30, when the power switch device in the power switch module 30 is short-circuited, the voltage between the first and second terminals of the power switch module 30 decreases, making the amplified voltage of the first diode D1 less than the reference voltage. Therefore, the first operational amplifier P2 outputs a low level, and the NOT gate U2 inverts the level output by the first operational amplifier P2, resulting in a high level output by the NOT gate U2. At this time, when the switch device Q1 is on and the drive output terminal of the driver chip 40 outputs a low level, the second input terminal of the AND gate U1 is low. Therefore, the AND gate U1 outputs a low level, and the switch module 20 is turned off, thus disconnecting the control circuit of the driver chip 40 to turn off the power switch module 30. When the switch device Q1 is off, the control circuit of the driver chip 40 to turn off the power switch module 30 is also in an open state.

[0129] When the control circuit of the power switch module 30 is disconnected by the driver chip 40, other power switch devices in the power switch module 30, except for the power switch device that is short-circuited, can be prevented from being turned off. The short-circuit current of the short-circuited power switch device generates a magnetic field, and other power switch devices are turned on under the coupling effect of this magnetic field. When the switch device Q1 is turned on and the drive output terminal of the driver chip 40 outputs a high level, the AND gate device U1 outputs a high level, and the switch module 20 is turned on. Since the drive output terminal of the driver chip 40 outputs a high level, the power switch module 30 is turned on, that is, every power switch device in the power switch module 30 is turned on.

[0130] When each power switch device in the power switch module 30 is turned on, the short-circuit current passing through the short-circuited power switch device can be reduced because the other power switch devices are connected in parallel with the short-circuited power switch device and the current is shunted. This reduces the risk of the short-circuit current causing the short-circuited power switch device to explode or catch fire due to the breakdown damage.

[0131] In some embodiments, the protection circuit includes a control module 10 and a switch module 20; the control module 10 includes a comparison submodule 11 and a control submodule 12; the protection circuit also includes a first resistor R1, a first diode D1 and a second diode D2; the comparison submodule 11 includes a second operational amplifier P3.

[0132] The first end of the first resistor R1 is electrically connected to the first input terminal of the second operational amplifier P3 and the desaturation protection input terminal of the driver chip 40, respectively. The second end of the first resistor R1 is electrically connected to the first end of the third resistor R3 and the positive terminal of the first diode D1, respectively. The negative terminal of the first diode D1 is electrically connected to the first end of the second resistor R2 and the positive terminal of the second diode D2, respectively. The negative terminal of the second diode D2 is electrically connected to the first terminal of the power switch module 30. The control submodule 12 includes a NOT gate device U2 and an AND gate device U1. The switch module 20 includes a sixth resistor R6 and a switch device Q1.

[0133] The second input terminal of the second operational amplifier P3 is used to obtain the reference voltage signal, and the output terminal of the second operational amplifier P3 is electrically connected to the input terminal of the NOT gate U2.

[0134] The output terminal of NOT gate device U2 is electrically connected to the first input terminal of AND gate device U1; the second input terminal of AND gate device U1 is electrically connected to the second terminal of switch device Q1; and the output terminal of AND gate device U1 is electrically connected to the control terminal of switch device Q1.

[0135] The first end of the sixth resistor R6 is electrically connected to the drive output terminal of the driver chip 40, and the second end of the sixth resistor R6 is electrically connected to the first end of the switching device Q1; the second end of the switching device Q1 is electrically connected to the control terminal of the power switch module 30.

[0136] In this embodiment, the second operational amplifier P3 is used to compare the voltage at the desaturation protection input terminal of the driver chip 40 with the reference voltage. Since the voltage at the desaturation protection input terminal of the driver chip 40 is positively correlated with the voltage between the first terminal and the second terminal of the power switch module 30, when the power switch device in the power switch module 30 breaks down and short-circuits, the voltage between the first terminal and the second terminal of the power switch module 30 decreases, making the voltage at the desaturation protection input terminal of the driver chip 40 less than the reference voltage. Therefore, the second operational amplifier P3 outputs a low level, and the NOT gate U2 inverts the level output by the second operational amplifier P3, so the NOT gate U2 outputs a high level. At this time, when the switch device Q1 is turned on and the drive output terminal of the driver chip 40 outputs a low level, the second input terminal of the AND gate U1 is at a low level. Therefore, the AND gate U1 outputs a low level, and the switch module 20 is turned off, thereby disconnecting the control circuit of the driver chip 40 to turn off the power switch module 30. The rest are similar to the above, and will not be described again here.

[0137] In some embodiments, the protection circuit includes a control module 10 and a switch module 20; the control module 10 includes a comparison submodule 11 and a control submodule 12; the comparison submodule 11 includes a third operational amplifier P4 and n fifth resistors R5, where n is a positive integer greater than 1;

[0138] The first terminal of the first fifth resistor R5 is electrically connected to the first terminal of the power switch module 30, the second terminal of the i-th fifth resistor R5 is electrically connected to the first terminal of the (i+1)-th fifth resistor R5, and the second terminal of the n-th fifth resistor R5 is electrically connected to the second terminal of the power switch module 30, where i is a positive integer less than n; the first input terminal of the third operational amplifier P4 is electrically connected to the second terminal of the i-th fifth resistor R5, the second input terminal of the third operational amplifier P4 is used to obtain the reference voltage signal, and the output terminal of the third operational amplifier P4 is electrically connected to the input terminal of the NOT gate device U2;

[0139] The output terminal of NOT gate device U2 is electrically connected to the first input terminal of AND gate device U1; the second input terminal of AND gate device U1 is electrically connected to the second terminal of switch device Q1; and the output terminal of AND gate device U1 is electrically connected to the control terminal of switch device Q1.

[0140] The first end of the sixth resistor R6 is electrically connected to the drive output terminal of the driver chip 40, and the second end of the sixth resistor R6 is electrically connected to the first end of the switching device Q1; the second end of the switching device Q1 is electrically connected to the control terminal of the power switch module 30.

[0141] In this embodiment, the third operational amplifier P4 is used to compare the voltage at its first input terminal with a reference voltage. The voltage at the first input terminal of the third operational amplifier P4 is the total voltage across the (i+1)th to the nth fifth resistor R5. Since the total voltage across the (i+1)th to the nth fifth resistor R5 is positively correlated with the voltage between the first and second terminals of the power switch module 30, in the event of a short circuit in the power switch device within the power switch module 30, the voltage between the first and second terminals of the power switch module 30... When the voltage decreases, the total voltage across the (i+1)th fifth resistor R5 to the nth fifth resistor R5 becomes less than the reference voltage. The third operational amplifier P4 then outputs a low level. The NOT gate U2 inverts the output level of the second operational amplifier P3, resulting in a high level output from the NOT gate U2. At this point, with the switching device Q1 on and the driver chip 40 outputting a low level, the second input of the AND gate U1 is also low. Therefore, the AND gate U1 outputs a low level, turning off the switching module 20 and disconnecting the control circuit of the driver chip 40 to turn off the power switching module 30. Other cases are similar to those described above and will not be repeated here.

[0142] Reference Figure 8 In some embodiments, the protection process of the power switch module 30 includes: X1, start; X2, low-voltage drive signal, i.e., driving the driver chip 40 to work; X3, driver board, i.e., the driver board (i.e., the driver chip 40) outputs a drive signal; X4, power module normal turn-on moment, i.e., the power module (i.e., the power switch module 30) is in a normal turn-on state; X5, power module conduction voltage drop detection, i.e., the voltage between the first terminal and the second terminal of the power module is detected by the comparator submodule 11; X6, comparator output is high, i.e., the comparator submodule... Block 11 output is high; X7, NOT gate (inverting), that is, the high level output of comparison sub-module 11 is inverted by the NOT gate; X8, power module gate voltage detection, that is, voltage detection at the second input terminal of AND gate device U1; X9, logic output is high, that is, the voltage at the second input terminal of AND gate device U1 is high; X10, AND gate, that is, the AND gate is used to determine, and the AND gate output is low at this time; X11, switching device Q1 is off, but body diode D8 is on, that is, switching device Q1 is off, but the body diode D8 (i.e., parasitic diode) of switching device Q1 is on;

[0143] X12. Power module normally shuts down, i.e., the power module is in the normally shut-off state; X13. Power module on-state voltage drop detection, i.e., the voltage between the first and second terminals of the power module is detected by the comparator submodule 11; X14. Comparator output is low, i.e., the output of the comparator submodule 11 is low; X15. NOT gate (inverting), i.e., the low level output of the comparator submodule 11 is inverted by the NOT gate; X16. Power module gate voltage detection, i.e., the voltage at the second input terminal of the AND gate device U1 is detected; X17. Logic output is high, i.e., the second input terminal of the AND gate device U1 is high; X18. AND gate, i.e., the AND gate is used to determine the output, and the AND gate output is high at this time; X19. Switching device Q1 is turned on;

[0144] X20. Load short circuit, i.e., a load short circuit fault (FUL) occurs in power switch module 30; X21. Power module on-state voltage drop detection, i.e., the voltage between the first and second terminals of the power module is detected by comparator submodule 11; X22. Comparator output high, i.e., the output of comparator submodule 11 is high; X23. NOT gate (inverting), i.e., the high level output of comparator submodule 11 is inverted by an NOT gate; X24. Power module gate voltage detection, i.e., the voltage at the second input terminal of AND gate device U1 is detected; X25. Logic output high, i.e., the second input terminal of AND gate device U1 is high; X2 6. AND gate: The AND gate is used to determine the output, which is low at this time; X27. Switching device Q1 is turned off: Switching device Q1 is turned off; X28. Desaturation protection is activated: The driver chip 40 detects an abnormal voltage between the first and second terminals of the power module through its desaturation protection input terminal and activates the desaturation protection; X29. Short circuit suppression: The driver chip 40 pulls the control terminal of the power switching module 30 low through its active Miller clamp terminal, causing the power switching module 30 to turn off and suppress the short circuit.

[0145] X30. Short circuit breakdown, i.e., a hard switching fault (HSF) occurs in power switch module 30; X31. Power module on-state voltage drop detection, i.e., the voltage between the first and second terminals of the power module is detected by comparator submodule 11; X32. Comparator output is low, i.e., the output of comparator submodule 11 is low; X33. NOT gate (inverting), i.e., the low level output of comparator submodule 11 is inverted by an NOT gate; X34. Power module gate voltage detection, i.e., the voltage at the second input terminal of AND gate device U1 is detected; X35. Logic output is low, i.e., the second input terminal of AND gate device U1 is low; X36. AND gate, i.e., the AND gate is used to determine the output, which is low at this time; X37, control gate floating, i.e., the switching device Q1 is turned off, making the gate of the power switching module 30 floating; X38, short circuit suppression, i.e., the short circuit current of the short-circuited power switching device generates a magnetic field, and other power switching devices are turned on under the coupling effect of this magnetic field. Since the other power switching devices are connected in parallel with the short-circuited power switching device and shunt the current, the short circuit current passing through the short-circuited power switching device can be reduced, thus reducing the risk of the short-circuited power switching device exploding or catching fire due to the short circuit current; X39, end.

[0146] In some embodiments, the protection circuit has four operating modes:

[0147] (1) Normal conduction mode of power switch module 30: When the driver chip 40 outputs a high level, the gate voltage of the power switch module 30 is controlled to be higher than the conduction threshold voltage of the power switch module 30 through the body diode D8 of the switching device Q1, thereby turning on the power switch module 30. At this time, due to the conduction of the power switch module 30, the voltage of the first diode D1 is greater than the reference voltage, the output of the first operational amplifier P2 is high, and after being inverted by the NOT gate U2, the NOT gate U2 outputs a low level. The second output terminal of the AND gate U1 is pulled high due to the high level output of the driver chip 40, and the output of the AND gate U1 is low, causing the switching device Q1 to be turned off. However, when the driver chip 40 outputs a high level, the power switch module 30 can be pulled high through the body diode D8 of the switching device Q1 to turn on the power switch module 30, so that the power switch module 30 can work normally.

[0148] (2) Normal shutdown mode of power switch module 30: When the driver chip 40 outputs a low level, the second output terminal of AND gate device U1 is kept at a high level under the action of the fourth capacitor C4, and the power switch module 30 is shut down, causing the voltage of the first diode D1 to be less than the reference voltage. The output of the first operational amplifier P2 is low level. After being inverted by the NOT gate device U2, the NOT gate device U2 outputs a high level, and then the AND gate device U1 outputs a high level, which makes the switch device Q1 conduct. The driver chip 40 can pull down the gate of the power switch module 30 to realize the shutdown of the power switch module 30.

[0149] (3) Power switch module 30 FUL short circuit mode: When the power switch module 30 is short-circuited, the voltage between the first terminal and the second terminal of the power switch module 30 increases instantaneously, triggering the desaturation protection function of the driver chip 40. At this time, the voltage of the first diode D1 is greater than the reference voltage, the output of the first operational amplifier P2 is high level, and after being inverted by the NOT gate device U2, the NOT gate device U2 outputs a low level. When the driver chip 40 outputs a high level, the AND gate device U1 outputs a low level, causing the switch device Q1 to turn off; when the driver chip 40 outputs a low level, the AND gate device U1 outputs a high level, causing the switch device Q1 to turn on; at the same time, the driver chip 40 pulls the control terminal of the power switch module 30 low through the active Miller clamp terminal of the driver chip 40, causing the power switch module 30 to turn off, so as to suppress the short circuit;

[0150] (4) HSF Short Circuit Mode of Power Switch Module 30: When an HSF short circuit occurs in power switch module 30, power switch module 30 is damaged. Due to the breakdown and short circuit of the power switching device in power switch module 30, the voltage between the first terminal and the second terminal of power switch module 30 decreases, causing the voltage of the first diode D1 to be less than the reference voltage. The output of the first operational amplifier P2 is low. After being inverted by the NOT gate U2, the NOT gate U2 outputs a high level. Since the driver chip 40 outputs a low level, the AND gate U1 outputs a low level. This causes the switching device Q1 to turn off, thereby disconnecting the control circuit of the power switching module 30 from the driver chip 40. This prevents other power switching devices in the power switching module 30 from turning off, except for the power switching device that has broken down and short-circuited. The short-circuit current of the power switching device that has broken down and short-circuited generates a magnetic field, and other power switching devices are turned on under the coupling effect of this magnetic field. Since the other power switching devices are connected in parallel with the power switching device that has broken down and short-circuited, the current is shunted, which can reduce the short-circuit current passing through the power switching device that has broken down and short-circuited, and reduce the risk of the power switching device that has broken down and short-circuited due to the short-circuit current exploding or catching fire.

[0151] The four operating modes of the protection circuit are similar when comparing the voltage at the desaturation protection input terminal of the driver chip 40 with the reference voltage via the second operational amplifier P3, or when comparing the total voltage of the (i+1)th fifth resistor R5 to the nth fifth resistor R5 with the reference voltage via the third operational amplifier P4, and will not be described in detail here.

[0152] This application also provides a protection method applied to the aforementioned protection circuit, the method comprising the following steps:

[0153] Step 101: Obtain the operating status of at least two parallel power switching devices.

[0154] The specific implementation process of this step is similar to that described above, and will not be repeated here.

[0155] Step 102: If any of the power switching devices is in an abnormal operating state, disconnect the control circuit of the power switching device.

[0156] The specific implementation process of this step is similar to that described above, and will not be repeated here.

[0157] In some embodiments, step 102 includes the following sub-steps:

[0158] Sub-step 1021: Disconnect the control circuit that turns off the power switching device.

[0159] The specific implementation process of this step is similar to that described above, and will not be repeated here.

[0160] In some embodiments, step 102 includes the following sub-steps:

[0161] Sub-step 1022: In the event of a short circuit in the power switching device, disconnect the control circuit.

[0162] The specific implementation process of this step is similar to that described above, and will not be repeated here.

[0163] This application embodiment also provides an inverter, including a multiphase bridge arm, a power switch module 30 and a protection circuit as described above, wherein the power switch module 30 is connected to the protection circuit and the power switch module 30 includes at least two power switch devices connected in parallel.

[0164] The implementation process of the protection circuit in the inverter is similar to that of the aforementioned protection circuit, and will not be repeated here.

[0165] In some embodiments, the inverter further includes a driver chip 40, which is connected to the power switch module 30 via the protection circuit.

[0166] In some embodiments, the bridge arm includes two half-bridges, each half-bridge including a power switch module; in the same bridge arm, the first terminal of the power switch module in the first half-bridge (i.e., the upper bridge arm) is electrically connected to the positive terminal of the power supply, the second terminal of the power switch module in the first half-bridge is electrically connected to the first terminal of the power switch module in the second half-bridge (i.e., the lower bridge arm), and the second terminal of the power switch module in the second half-bridge is grounded.

[0167] In some embodiments, if a power switching module of one half-bridge of the inverter experiences a short circuit (HSF), i.e., if a power switching device in the power switching module of one half-bridge of the inverter experiences a breakdown short circuit, the power switching modules of the other half-bridges in the inverter that experienced the HSF are controlled to be turned off.

[0168] For example, refer to Figure 9 The inverter includes a multi-phase bridge arm A1, each of which includes two power switch modules 30, and each power switch module is equipped with the protection circuit described above. Each bridge arm A1 includes two half-bridges, each half-bridge including one power switch module 30, and each power switch module 30 including four power switching devices a1. The inverter also includes three first electrodes HV+, three second electrodes HV-, and three bridge arm output terminals AC-OUT, with each bridge arm A1 having corresponding first electrodes HV+, second electrodes HV-, and bridge arm output terminals AC-OUT. Specifically, in the same bridge arm A1, the first terminal of the power switch module 30 in the first half-bridge (i.e., the upper bridge arm) is electrically connected to the first electrode HV+, the second terminal of the power switch module 30 in the first half-bridge is electrically connected to the first terminal of the power switch module 30 in the second half-bridge (i.e., the lower bridge arm), the second terminal of the power switch module 30 in the second half-bridge is electrically connected to the second electrode HV-, and the bridge arm output terminal AC-OUT is electrically connected to the second terminal of the power switch module 30 in the first half-bridge and the first terminal of the power switch module 30 in the second half-bridge, respectively.

[0169] This application also provides a vehicle that includes the protection circuit described above, or includes an inverter as described above.

[0170] The implementation process of the protection circuit in the vehicle is similar to that of the aforementioned protection circuit, and will not be repeated here.

[0171] In this embodiment, when a short circuit occurs in the power switch module 30, the short circuit severity of the power switch module 30 can be suppressed, preventing damage to other power switch modules 30 besides the one experiencing a short circuit (HSF). When a short circuit occurs in one power switch device within the power switch module 30, by leaving the gate of the power switch device floating, multiple power switch devices can share the short circuit current, preventing excessive short circuit current in a single power switch device from causing a rapid temperature rise and explosion, while simultaneously suppressing the short circuit severity of the entire inverter.

[0172] In this embodiment, by leaving the gate of the power switching device floating, the damage level at the inverter level is reduced, achieving short-circuit protection at the entire system level. Fault-tolerant judgment is achieved through the logic judgment circuit of AND gate device U1 and NOT gate device U2, preventing false triggering that could shut down the entire inverter. When an HSF (High-Speed ​​Current) is detected in the power switching module 30, and the gate waveform of the power switching module 30 is negative or 0V, the control module 10 controls the gate of the short-circuit power switching module 30 to be left floating, causing each power switching device inside the power switching module 30 to conduct and jointly bear the short-circuit current, thus mitigating the damage. When an FUL (Failure to Safe) is detected in the power switching module 30, the desaturation function of the driver chip 40 is activated, shutting down the power switching module 30 and protecting the hardware from damage. The protection circuit and the desaturation function of the driver chip 40 form multiple protections, increasing the safety of the power switching module 30.

[0173] Compared with related technologies that detect the Kelvin source pin of the power switch module, the embodiments of this application do not require the power switch module to have a Kelvin source pin, which is more versatile. At the same time, the addition of logic judgment circuitry reduces the probability of false triggering.

[0174] Compared with the gate current detection of the power switch module in related technologies, the embodiments of this application detect the voltage between the first terminal and the second terminal of the power switch module and the gate voltage of the power switch module. The two detection methods are carried out in parallel and the judgment is made by a logic judgment circuit, which reduces the probability of false triggering, improves safety, and covers a wider range of short circuit protection for the power switch module.

[0175] In summary, in this embodiment, when a power switch device in the power switch module 30 experiences a short circuit, the control module 10 controls the switch module 20 to turn off. Furthermore, when the switch module 20 is off, the drive chip 40 disconnects the control circuit of the power switch module 30, thus preventing other power switch devices in the power switch module 30 from turning off. The short-circuit current of the short-circuited power switch device generates a magnetic field, which causes other power switch devices to conduct under the coupling effect of this magnetic field. Since the other power switch devices are connected in parallel with the short-circuited power switch device and shunt the current, the short-circuit current passing through the short-circuited power switch device can be reduced, thereby lowering the risk of the damaged power switch device exploding or catching fire due to the short-circuit current.

[0176] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited. Functions may be performed in the order shown or discussed, or may be performed substantially simultaneously or in reverse order depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0177] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A protection circuit, characterized in that, include: The drive end, the end to be protected, the control module (10), and the switch module (20) are included. The driving terminal is used to input driving signals; The terminal to be protected is used to connect at least two power switching devices connected in parallel; The first end of the switch module (20) is electrically connected to the drive end; The first end of the control module (10) is electrically connected to the second end of the switch module (20), and the second end of the control module (10) and the third end of the switch module (20) are electrically connected to the end to be protected. The control module (10) is used to control the switch module (20) to shut down in case any of the power switching devices in the protected terminal malfunctions, thereby disconnecting the control circuit of the power switching device.

2. The protection circuit according to claim 1, characterized in that, The driving end is used to be electrically connected to the driving chip (40) of the power switching device; The control module (10) is used to disconnect the control circuit of the driver chip (40) controlling the power switching device.

3. The protection circuit according to claim 1, characterized in that, The control module (10) includes a comparison submodule (11) and a control submodule (12); The comparison submodule (11) is electrically connected to the control submodule (12), and the comparison submodule (11) is used to be electrically connected to the end to be protected; The control submodule (12) is electrically connected to the switch module (20); The comparison submodule (11) is used to determine whether an abnormality has occurred at the end to be protected; The control submodule (12) is used to send a drive signal to the switch module (20) to turn off the switch module (20) in the event of an abnormality at the protected end.

4. The protection circuit according to claim 3, characterized in that, The comparison submodule (11) includes an operational amplifier; the first input terminal of the operational amplifier is located between the driving terminal and the terminal to be protected, the second input terminal of the operational amplifier is connected to a potential reference point, and the output terminal of the operational amplifier is electrically connected to the first input terminal of the control submodule (12).

5. The protection circuit according to claim 4, characterized in that, The protection circuit also includes a first diode (D1); the first diode (D1) is disposed between the driving end and the end to be protected, and the first input end and the second input end of the comparison submodule (11) are respectively disposed at the two ends of the first diode (D1).

6. The protection circuit according to claim 5, characterized in that, The comparison submodule (11) further includes a voltage acquisition unit; the voltage acquisition unit is disposed between the operational amplifier and the driver terminal.

7. The protection circuit according to claim 6, characterized in that, The voltage acquisition unit includes a voltage amplifier (P1), the first input terminal of which is located at the negative terminal of the first diode (D1), and the second input terminal of which is located at the positive terminal of the first diode (D1); the first input terminal and the second input terminal of the voltage amplifier (P1) respectively constitute the first input terminal and the second input terminal of the comparison submodule (11).

8. The protection circuit according to claim 7, characterized in that, The operational amplifier includes a first operational amplifier (P2). ； The first input terminal of the first operational amplifier (P2) is electrically connected to the output terminal of the voltage amplifier (P1), the second input terminal of the first operational amplifier (P2) is used to obtain a reference voltage signal, and the output terminal of the first operational amplifier (P2) is electrically connected to the first input terminal of the control submodule (12).

9. The protection circuit according to claim 7, characterized in that, The voltage acquisition unit further includes a second resistor (R2) and a third resistor (R3): the second resistor (R2) is disposed between the positive terminal of the first diode (D1) and the first input terminal of the voltage amplifier (P1), and the third resistor (R3) is disposed between the negative terminal of the first diode (D1) and the second input terminal of the voltage amplifier (P1).

10. The protection circuit according to claim 9, characterized in that, The voltage acquisition unit further includes: The first capacitor (C1) has its first terminal electrically connected to the second terminal of the second resistor (R2) and the first input terminal of the voltage amplifier (P1), and its second terminal is grounded. And / or, a second capacitor (C2), the first terminal of which is electrically connected to the first input terminal of the voltage amplifier (P1), and the second terminal of which is grounded.

11. The protection circuit according to claim 7, characterized in that, The voltage acquisition unit also includes a fourth resistor (R4); The first end of the fourth resistor (R4) is electrically connected to the output terminal of the voltage amplifier (P1), and the second end of the fourth resistor (R4) is electrically connected to the second input terminal of the voltage amplifier (P1).

12. The protection circuit according to claim 7, characterized in that, The voltage acquisition unit also includes a clamping unit; The first end of the clamping unit is electrically connected to the first input end of the voltage amplifier (P1), and the second end of the clamping unit is grounded.

13. The protection circuit according to claim 5, characterized in that, The operational amplifier (11) includes a second operational amplifier (P3); The first input terminal of the second operational amplifier (P3) is located between the first diode (D1) and the driving terminal.

14. The protection circuit according to claim 4, characterized in that, The comparison submodule (11) further includes an eighth resistor (R8) and a fifth resistor (R5); the eighth resistor (R8) and the fifth resistor (R5) are connected in series; the series branch formed by the eighth resistor (R8) and the fifth resistor (R5) is connected in parallel with the power switching device.

15. The protection circuit according to claim 14, characterized in that, The operational amplifier includes a third operational amplifier (P4), the first input terminal of which is electrically connected between the fifth resistor (R5) and the eighth resistor (R8).

16. The protection circuit according to claim 3, characterized in that, The control submodule (12) includes a NOT gate device (U2); The input terminal of the NOT gate device (U2) is electrically connected to the output terminal of the comparator submodule (11).

17. The protection circuit according to claim 16, characterized in that, The control submodule (12) also includes an AND gate device (U1); The first input terminal of the AND gate device (U1) is electrically connected to the output terminal of the NOT gate device (U2), the second input terminal of the AND gate device (U1) is electrically connected to the second terminal of the switch module (20), and the output terminal of the AND gate device (U1) is electrically connected to the control terminal of the switch module (20).

18. The protection circuit according to any one of claims 1 to 17, characterized in that, The switching module (20) includes a switching device (Q1); The second terminal of the switching device (Q1) is electrically connected to the input terminal of the control module (10) and the control terminal of the power switching device, respectively, and the control terminal of the switching device (Q1) is electrically connected to the output terminal of the control module (10).

19. The protection circuit according to claim 18, characterized in that, The switching module (20) further includes a sixth resistor (R6), the first end of which is electrically connected to the driving end, and the second end of which is electrically connected to the first end of the switching device (Q1).

20. The protection circuit according to any one of claims 1 to 17, characterized in that, The switching module (20) also includes a body diode (D8); The positive terminal of the body diode (D8) is electrically connected to the driving terminal, and the negative terminal of the body diode (D8) is electrically connected to the third terminal of the control module (10) and the control terminal of the power switching device, respectively.

21. The protection circuit according to any one of claims 1 to 17, characterized in that, The protection circuit also includes a first protection module; The first terminal of the first protection module is electrically connected to the driving terminal, and the second terminal of the first protection module is grounded.

22. The protection circuit according to any one of claims 1 to 17, characterized in that, The protection circuit also includes a second protection module; The first terminal of the second protection module is electrically connected to the control terminal of the power switching device, and the second terminal of the second protection module is grounded.

23. The protection circuit according to any one of claims 1 to 17, characterized in that, The protection circuit also includes a third protection module; The first end of the third protection module is electrically connected to the driving end, and the second end of the third protection module is electrically connected to the first end of the power switching device.

24. A protection method, characterized in that, Applied to the protection circuit as described in claims 1 to 23, the method includes: Obtain the operating status of at least two power switching devices connected in parallel; If any of the power switching devices malfunctions, disconnect the control circuit of the power switching device.

25. The method according to claim 24, characterized in that, The control circuit for disconnecting the power switching device includes: Disconnect the control circuit that shuts off the power switching device.

26. The method according to claim 24, characterized in that, The step of disconnecting the control circuit of the power switching device when any of the power switching devices is in an abnormal operating state includes: In the event of a short circuit in the power switching device, disconnect the control circuit.

27. An inverter, characterized in that, It includes a multiphase bridge arm, a power switch module (30), and a protection circuit as described in any one of claims 1 to 23, wherein the power switch module (30) is connected to the protection circuit, and the power switch module (30) includes at least two power switching devices connected in parallel.

28. The inverter according to claim 27, characterized in that, The inverter also includes a driver chip (40), which is connected to the power switch module (30) through the protection circuit.

29. A vehicle, characterized in that, It includes the protection circuit as described in any one of claims 1 to 23, or the inverter as described in claim 27 or 28.

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