IGBT protection circuit and power supply device

Abstract

The invention is applicable to the technical field of IGBT protection, and provides an IGBT protection circuit and a power supply device.The IGBT protection circuit comprises a first detection module, a second detection module and a control module, the control module is electrically connected with the first detection module and the second detection module, the first detection module is electrically connected with the input end of an IGBT, and the second detection module is electrically connected with the output end of the IGBT. The second detection module is electrically connected with the output end of the IGBT, and the control module is electrically connected with the control end of the IGBT. The IGBT protection circuit provided by the embodiment of the invention can quickly respond and control all IGBTs to stop working when the positive half cycle or the negative half cycle of the AC voltage is short-circuited, thereby effectively protecting the IGBT device and reducing the risk of damage to the IGBT device.

Description

Technical Field

[0001] This application belongs to the technical field of IGBT protection, and particularly relates to an IGBT protection circuit and a power supply device. Background Art

[0002] In an AC power system, a short-circuit fault may cause serious consequences such as an electrical fire. To prevent such accidents, IGBT (Insulated Gate Bipolar Transistor) is usually used for power drive and short-circuit detection, and short-circuit protection is achieved within microseconds. However, under special working conditions, overcurrent or short-circuit will cause a sudden increase in the IGBT current, resulting in a rapid increase in its junction temperature and damage. Currently, short-circuit detection in AC products usually adopts a current detection scheme, that is, short-circuit is judged by monitoring the current mutation in the circuit. However, due to the capacitive problem of the load during the actual operation of the product, this scheme is very prone to false short-circuit alarms. More critically, once a short-circuit actually occurs, the existing technology is difficult to respond quickly and protect the IGBT device, resulting in a very high risk of damage to the IGBT device during a short-circuit fault. Summary of the Invention

[0003] The embodiments of this application provide an IGBT protection circuit and a power supply device, which can solve the problem that the existing current detection scheme for judging short-circuit is difficult to respond quickly and protect the IGBT device, resulting in a very high risk of damage to the IGBT device during a short-circuit fault.

[0004] In a first aspect, the embodiments of this application provide an IGBT protection circuit, including a first detection module, a second detection module, and a control module. The control module is electrically connected to the first detection module and the second detection module respectively. The first detection module is electrically connected to the input end of the IGBT, the second detection module is electrically connected to the output end of the IGBT, and the control module is electrically connected to the control end of the IGBT;

[0005] The first detection module is configured to detect a first voltage at the input end of the IGBT, and output a first detection signal to the control module according to the first voltage and a reference voltage; the control module is configured to determine whether the first voltage is abnormal according to the first detection signal, and output a first control signal to the control end of the IGBT when the first voltage is abnormal, and the first control signal is used to instruct the IGBT to stop working; the second detection module is configured to detect a second voltage at the output end of the IGBT, and output a second detection signal to the control module according to the second voltage and the reference voltage; the control module is further configured to determine whether the second voltage is abnormal according to the second detection signal, and output a second control signal to the control end of the IGBT when the second voltage is abnormal, and the second control signal is used to instruct the IGBT to stop working.

[0006] In a possible implementation of the first aspect, the first detection module includes a first comparison unit and a first adjustment unit. The first comparison unit is electrically connected to the first adjustment unit and the control module respectively, and the first adjustment unit is electrically connected to the input end of the IGBT;

[0007] The first adjustment unit is configured to output a first adjustment voltage to the first comparison unit according to the first voltage, and the first comparison unit is configured to output the first detection signal to the control module when the first adjustment voltage is greater than the reference voltage.

[0008] In a possible implementation of the first aspect, the first comparison unit includes a first operational amplifier, a first resistor, a second resistor, and a third resistor. The first input end of the first operational amplifier is electrically connected to the first end of the second resistor, the second input end of the first operational amplifier is electrically connected to the first end of the third resistor, the output end of the first operational amplifier is electrically connected to the control module, the first end of the first resistor is configured to be electrically connected to a first power supply, the second end of the first resistor is electrically connected to the second end of the second resistor and the first adjustment unit respectively, and the second end of the third resistor is configured to receive the reference voltage.

[0009] In a possible implementation of the first aspect, the first adjustment unit includes a first diode. The anode of the first diode is electrically connected to the second end of the first resistor and the second end of the second resistor respectively, and the cathode of the first diode is electrically connected to the input end of the IGBT.

[0010] In a possible implementation of the first aspect, the second detection module includes a second comparison unit and a second adjustment unit. The second comparison unit is electrically connected to the second adjustment unit and the control module respectively, and the second adjustment unit is electrically connected to the output end of the IGBT;

[0011] The second adjustment unit is configured to output a second adjustment voltage to the second comparison unit according to the second voltage, and the second comparison unit is configured to output the second detection signal to the control module when the second adjustment voltage is greater than the reference voltage.

[0012] In a possible implementation of the first aspect, the second comparison unit includes a second operational amplifier, a fourth resistor, a fifth resistor, and a sixth resistor. The first input terminal of the second operational amplifier is electrically connected to the first end of the fifth resistor. The second input terminal of the second operational amplifier is electrically connected to the first end of the sixth resistor. The output terminal of the second operational amplifier is electrically connected to the control module. The first end of the fourth resistor is used to be electrically connected to a second power supply. The second end of the fourth resistor is respectively electrically connected to the second end of the fifth resistor and the second adjustment unit. The second end of the sixth resistor is used to receive the reference voltage.

[0013] In a possible implementation of the first aspect, the second adjustment unit includes a second diode. The anode of the second diode is respectively electrically connected to the second end of the fourth resistor and the second end of the fifth resistor. The cathode of the second diode is electrically connected to the output terminal of the IGBT.

[0014] In a possible implementation of the first aspect, the IGBT protection circuit further includes a reference module. The reference module is respectively electrically connected to the first detection module and the second detection module. The reference module is used to output the reference voltage to the first detection module and the second detection module respectively.

[0015] In a possible implementation of the first aspect, the reference module includes a third operational amplifier, a fifteenth resistor, a sixteenth resistor, and a seventeenth resistor. The first input terminal of the third operational amplifier is electrically connected to the first end of the fifteenth resistor. The second input terminal of the third operational amplifier is electrically connected to the first end of the sixteenth resistor. The output terminal of the third operational amplifier is respectively electrically connected to the second end of the sixteenth resistor, the first detection module, and the second detection module. The first end of the seventeenth resistor is respectively electrically connected to the second end of the fifteenth resistor and a third power supply. The second end of the seventeenth resistor is grounded.

[0016] In a second aspect, an embodiment of the present application provides a power supply device, including an IGBT and the IGBT protection circuit according to any one of the first aspect. The input terminal of the IGBT is electrically connected to the first detection module in the IGBT protection circuit. The output terminal of the IGBT is electrically connected to the second detection module in the IGBT protection circuit. The control terminal of the IGBT is electrically connected to the control module in the IGBT protection circuit.

[0017] The beneficial effects of the embodiments of the present application compared with the prior art are:

[0018] The IGBT protection circuit provided by the embodiment of the present application includes a first detection module, a second detection module, and a control module. Among them, the first detection module is used to detect a first voltage and output a first detection signal to the control module according to the first voltage and a reference voltage. The control module determines whether the first voltage is abnormal according to the first detection signal, that is, determines whether a short-circuit fault occurs in the positive half-cycle of the AC voltage. When the first voltage is abnormal, that is, it is determined that a short-circuit fault occurs in the positive half-cycle of the AC voltage. At this time, the control module outputs a first control signal to control the IGBT to stop working, thereby protecting the IGBT device. Similarly, the second detection module is used to detect a second voltage and output a second detection signal to the control module according to the second voltage and the reference voltage. The control module determines whether the second voltage is abnormal according to the second detection signal, that is, determines whether a short-circuit fault occurs in the negative half-cycle of the AC voltage. When the second voltage is abnormal, that is, it is determined that a short-circuit fault occurs in the negative half-cycle of the AC voltage. At this time, the control module outputs a second control signal to control the IGBT to stop working, thereby protecting the IGBT device. It can be seen from this that the IGBT protection circuit provided by the embodiment of the present application can quickly respond when a short circuit occurs in the positive half-cycle or negative half-cycle of the AC voltage, control all IGBTs to stop working, thereby effectively protecting the IGBT device and reducing the risk of damage to the IGBT device. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 is a schematic block diagram of the IGBT protection circuit provided by an embodiment of the present application;

[0021] Figure 2 is a schematic circuit connection diagram of the IGBT protection circuit provided by an embodiment of the present application;

[0022] Figure 3 is a schematic block diagram of the IGBT protection circuit provided by another embodiment of the present application.

[0023] In the figure: 10, IGBT protection circuit; 101, first detection module; 1011, first comparison unit; 1012, first adjustment unit; 102, second detection module; 1021, second comparison unit; 1022, second adjustment unit; 103, control module; 104, reference module. Detailed Embodiments

[0024] In the following description, specific details such as specific system architectures, technologies, etc. are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present application. However, those skilled in the art should clearly understand that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present application.

[0025] It should be understood that when used in the specification of the present application and the appended claims, the term "comprising" indicates the presence of the described features, wholes, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0026] As used in the specification of the present application and the appended claims, the term "if" can be interpreted as "when" or "once" or "in response to determining" or "in response to detecting" according to the context. Similarly, the phrase "if determined" or "if [the described condition or event] is detected" can be interpreted as meaning "once determined" or "in response to determining" or "once [the described condition or event] is detected" or "in response to detecting [the described condition or event]" according to the context.

[0027] In addition, in the description of the specification of the present application and the appended claims, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0028] The reference to "one embodiment" or "some embodiments" or the like described in the specification of the present application means that a specific feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in another way. The terms "comprising", "including", "having", and their variants all mean "including but not limited to", unless otherwise specifically emphasized in another way.

[0029] In an AC power system, a short-circuit fault may cause serious consequences such as an electrical fire. To prevent such accidents, IGBTs are usually used for power drive and short-circuit detection, and short-circuit protection is achieved within microseconds. However, under special operating conditions, overcurrent or short-circuit will cause a sudden increase in the IGBT current, resulting in a rapid increase in its junction temperature and damage. Currently, current detection schemes are usually adopted for short-circuit detection in AC products, that is, short-circuit is judged by monitoring the current mutation in the circuit. However, due to the widespread capacitive problems of loads during the actual operation of products, this scheme is very prone to false short-circuit alarms. More critically, once a real short-circuit occurs, it is difficult for the existing technology to respond quickly and protect the IGBT device, resulting in a very high risk of damage to the IGBT device during a short-circuit fault.

[0030] Based on the above problems, the IGBT protection circuit provided in the embodiment of the present application includes a first detection module, a second detection module, and a control module. Among them, the first detection module is used to detect a first voltage and output a first detection signal to the control module according to the first voltage and a reference voltage. The control module judges whether the first voltage is abnormal according to the first detection signal, that is, judges whether a short-circuit fault occurs in the positive half-cycle of the AC voltage. When the first voltage is abnormal, that is, it is determined that a short-circuit fault occurs in the positive half-cycle of the AC voltage. At this time, the control module outputs a first control signal to control the IGBT to stop working, thereby protecting the IGBT device. Similarly, the second detection module is used to detect a second voltage and output a second detection signal to the control module according to the second voltage and the reference voltage. The control module judges whether the second voltage is abnormal according to the second detection signal, that is, judges whether a short-circuit fault occurs in the negative half-cycle of the AC voltage. When the second voltage is abnormal, that is, it is determined that a short-circuit fault occurs in the negative half-cycle of the AC voltage. At this time, the control module outputs a second control signal to control the IGBT to stop working, thereby protecting the IGBT device. It can be seen that the IGBT protection circuit provided in the embodiment of the present application can quickly respond when a short-circuit occurs in the positive half-cycle or negative half-cycle of the AC voltage, control all IGBTs to stop working, thereby effectively protecting the IGBT device and reducing the risk of damage to the IGBT device.

[0031] To illustrate the technical solution described in the present application, the following will be described through specific embodiments.

[0032] Figure 1 The principle block diagram of the IGBT protection circuit 10 provided in an embodiment of the present application is shown. Refer to Figure 1 As shown, the IGBT protection circuit 10 includes a first detection module 101, a second detection module 102, and a control module 103. The control module 103 is electrically connected to the first detection module 101 and the second detection module 102 respectively. The first detection module 101 is electrically connected to the input end of the IGBT, the second detection module 102 is electrically connected to the output end of the IGBT, and the control module 103 is electrically connected to the control end of the IGBT.

[0033] Specifically, taking Figure 1 as an example, the input terminal of the IGBT serves as the live wire input for electrical connection to the AC power supply. The control terminal of the IGBT serves as the IGBT drive and is electrically connected to the control module 103. The output terminal of the IGBT serves as the live wire output for electrical connection to the load. During AC power supply, the load is connected between the live wire output and the neutral wire, and the AC input voltage is applied between the live wire input and the neutral wire. Since the AC input voltage is periodic, there are a positive half-cycle and a negative half-cycle of the AC voltage. The process of the AC voltage being transmitted from the live wire input through the IGBT to the live wire output is the positive half-cycle, and the process of the AC voltage being transmitted from the live wire output through the IGBT to the live wire input is the negative half-cycle, thereby realizing the provision of alternating current to the load.

[0034] The first detection module 101 is used to detect the first voltage at the input terminal of the IGBT and output a first detection signal to the control module 103 based on the first voltage and the reference voltage. The control module 103 determines whether the first voltage is abnormal based on the first detection signal, that is, determines whether a short-circuit fault occurs in the positive half-cycle of the AC voltage. When the first voltage is abnormal, that is, it is determined that a short-circuit fault occurs in the positive half-cycle of the AC voltage. At this time, the control module outputs a first control signal to control the IGBT to stop working, thereby protecting the IGBT device. Similarly, the second detection module 102 is used to detect the second voltage at the output terminal of the IGBT and output a second detection signal to the control module 103 based on the second voltage and the reference voltage. The control module 103 determines whether the second voltage is abnormal based on the second detection signal, that is, determines whether a short-circuit fault occurs in the negative half-cycle of the AC voltage. When the second voltage is abnormal, that is, it is determined that a short-circuit fault occurs in the negative half-cycle of the AC voltage. At this time, the control module outputs a second control signal to control the IGBT to stop working, thereby protecting the IGBT device. It can be seen from this that the IGBT protection circuit 10 provided by the embodiment of the present application can quickly respond when a short circuit occurs in the positive half-cycle or the negative half-cycle of the AC voltage, control the IGBT to stop working, thereby effectively protecting the IGBT device and reducing the risk of damage to the IGBT device.

[0035] It should be noted that, as Figure 1As shown, the first switching transistor Q1, the second switching transistor Q2, the third switching transistor Q3, and the fourth switching transistor Q4 are all IGBT transistors. The drain of the first switching transistor Q1 and the drain of the second switching transistor Q2 serve as the input end of the IGBT. The drain of the third switching transistor Q3 and the drain of the fourth switching transistor Q4 serve as the output end of the IGBT. The gates of the first switching transistor Q1, the second switching transistor Q2, the third switching transistor Q3, and the fourth switching transistor Q4 serve as the control end of the IGBT. The first switching transistor Q1, the second switching transistor Q2, the third switching transistor Q3, and the fourth switching transistor Q4 form a full-bridge circuit, and a body diode is provided between the drain and the source of each of the first switching transistor Q1, the second switching transistor Q2, the third switching transistor Q3, and the fourth switching transistor Q4. Current can form a loop through the drain, source of the first switching transistor Q1, and the body diode of the fourth switching transistor Q4. Current can also form a loop through the drain, source of the third switching transistor Q3, and the body diode of the second switching transistor Q2.

[0036] In an embodiment of the present application, as Figure 1 shown, the first switching transistor Q1, the second switching transistor Q2, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, and the tenth resistor R10 constitute a first driving module. The common terminal of the first end of the seventh resistor R7 and the first end of the ninth resistor R9 serves as the control end of the first driving module. The first end of the seventh resistor R7 and the first end of the ninth resistor R9 are both electrically connected to the control module 103. The second end of the seventh resistor R7 is electrically connected to the gate of the first switching transistor Q1 and the first end of the eighth resistor R8 respectively. The second end of the ninth resistor R9 is electrically connected to the gate of the second switching transistor Q2 and the first end of the tenth resistor R10 respectively. The common terminal of the drain of the first switching transistor Q1 and the drain of the second switching transistor Q2 serves as the first end of the first driving module. The drain of the first switching transistor Q1 and the drain of the second switching transistor Q2 are both electrically connected to the first detection module 101. The common terminal of the source of the first switching transistor Q1 and the source of the second switching transistor Q2 serves as the second end of the first driving module. The source of the first switching transistor Q1 is electrically connected to the second driving module and the second end of the eighth resistor R8 respectively, and is grounded. The source of the second switching transistor Q2 is electrically connected to the second driving module and the second end of the tenth resistor R10 respectively, and is grounded.

[0037] Specifically, the seventh resistor R7 and the eighth resistor R8 serve as voltage dividing resistors for adjusting the gate voltage of the first switching transistor Q1. The ninth resistor R9 and the tenth resistor R10 serve as voltage dividing resistors for adjusting the gate voltage of the second switching transistor Q2. Both the first switching transistor Q1 and the second switching transistor Q2 act as switching devices and can be turned on or off according to the driving voltage signal received at the gate. When the driving voltage signal received at the gate is a high-level signal, the first switching transistor Q1 and the second switching transistor Q2 are turned on. When the driving voltage signal received at the gate is a low-level signal (such as the above-mentioned first control signal and second control signal), the first switching transistor Q1 and the second switching transistor Q2 are turned off. When there is no short-circuit fault in the positive half-cycle of the AC voltage, both the first switching transistor Q1 and the second switching transistor Q2 are turned on, and the drain-source voltage (the voltage difference Vce between the collector and the emitter) of the first switching transistor Q1 and the second switching transistor Q2 is very small. At this time, the cathode of the first diode D1 is grounded through the first switching transistor Q1 or the second switching transistor Q2. When there is a short-circuit fault in the positive half-cycle of the AC voltage, the Vce of the first switching transistor Q1 and the second switching transistor Q2 will increase sharply, resulting in a sharp increase in the first voltage (a sharp increase in the first voltage can indicate an abnormality of the first voltage).

[0038] In an embodiment of the present application, as Figure 1 shown, the third switching transistor Q3, the fourth switching transistor Q4, the eleventh resistor R11, the twelfth resistor R12, the thirteenth resistor R13, and the fourteenth resistor R14 form a second driving module. The common terminal of the first end of the eleventh resistor R11 and the first end of the thirteenth resistor R13 serves as the control terminal of the second driving module. The first ends of the eleventh resistor R11 and the thirteenth resistor R13 are both electrically connected to the control module 103. The second end of the eleventh resistor R11 is electrically connected to the gate of the third switching transistor Q3 and the first end of the twelfth resistor R12 respectively. The second end of the thirteenth resistor R13 is electrically connected to the gate of the fourth switching transistor Q4 and the first end of the fourteenth resistor R14 respectively. The common terminal of the drain of the third switching transistor Q3 and the drain of the fourth switching transistor Q4 serves as the first end of the second driving module. The drains of the third switching transistor Q3 and the fourth switching transistor Q4 are both electrically connected to the second detection module 102. The common terminal of the source of the third switching transistor Q3 and the source of the fourth switching transistor Q4 serves as the second end of the second driving module. The source of the third switching transistor Q3 is electrically connected to the first driving module and the second end of the twelfth resistor R12 respectively and is grounded. The source of the fourth switching transistor Q4 is electrically connected to the first driving module and the second end of the fourteenth resistor R14 respectively and is grounded.

[0039] Specifically, the eleventh resistor R11 and the twelfth resistor R12 serve as voltage dividing resistors for adjusting the gate voltage of the third switching transistor Q3. The thirteenth resistor R13 and the fourteenth resistor R14 serve as voltage dividing resistors for adjusting the gate voltage of the fourth switching transistor Q4. Both the third switching transistor Q3 and the fourth switching transistor Q4 are used as switching devices, which can be turned on or off according to the driving voltage signal received by the gate. When the driving voltage signal received by the gate is a high-level signal, the third switching transistor Q3 and the fourth switching transistor Q4 are turned on. When the driving voltage signal received by the gate is a low-level signal (such as the above-mentioned first control signal and second control signal), the third switching transistor Q3 and the fourth switching transistor Q4 are turned off. When there is no short-circuit fault in the negative half cycle of the AC voltage, both the third switching transistor Q3 and the fourth switching transistor Q4 are turned on, and the drain-source voltage (the voltage difference Vce between the collector and the emitter) of the third switching transistor Q3 and the fourth switching transistor Q4 is very small. When a short-circuit fault occurs in the negative half cycle of the AC voltage, the Vce of the third switching transistor Q3 and the fourth switching transistor Q4 will increase sharply, resulting in a sharp increase in the second voltage (a sharp increase in the second voltage can indicate an abnormality of the second voltage).

[0040] It should be noted that when the IGBT protection circuit 10 determines that a short-circuit fault has occurred in the line, the control module 103 immediately controls all IGBT devices to stop working, thereby cutting off the power supply circuit between the input voltage and the load. This not only protects the IGBT devices but also effectively prevents the load from being damaged by the short-circuit current, significantly improving the safety and reliability of the AC power supply system.

[0041] It should be noted that both the first control signal and the second control signal output by the control module 103 are enable signals for controlling the IGBT to turn off. When the control module 103 determines that a short-circuit fault has occurred, regardless of whether the short-circuit fault occurs in the positive half cycle or the negative half cycle of the AC voltage, the control module 103 will output a turn-off control signal simultaneously to ensure that the IGBT stops working, thereby cutting off the current path and minimizing the damage to the IGBT protection circuit 10 and the load caused by the short-circuit current, achieving comprehensive and reliable control.

[0042] It should be noted that the first voltage detected by the first detection module 101 is the voltage in the positive half-cycle of the AC voltage, and the second voltage detected by the second detection module 102 is the voltage in the negative half-cycle of the AC voltage. Among them, the positive and negative half-cycles of the AC voltage are symmetrically designed. When there is no short-circuit fault in the circuit, that is, when the AC voltage is normally transmitted to the load, the first voltage is equal to the second voltage. Since the first voltage and the second voltage are equal when there is no short-circuit fault, in this application, only by comparing the first voltage and the second voltage with the same reference voltage can short-circuit detection be achieved. In addition, the design scheme uses the first detection module 101 and the second detection module 102 to detect the first voltage and the second voltage, and outputs the first detection signal / second detection signal according to the first voltage / second voltage and the reference voltage, which is more accurate for short-circuit detection. The short-circuit judgment of the product is not affected by the change of the load capacitive load, and the short-circuit protection time is shorter.

[0043] It should be noted that if there are different protection requirements or thresholds for the positive and negative half-cycles of the AC voltage in the circuit design, for example, the load characteristics of the positive and negative half-cycles are different, resulting in different sensitivities of the short-circuit current. At this time, it may be necessary to set different reference voltages for the positive and negative half-cycles respectively. If the types of short-circuit faults that may occur in the positive and negative half-cycles are different, for example, overcurrent is more likely to occur in the positive half-cycle, while overvoltage is more likely to occur in the negative half-cycle. At this time, it may be necessary to set different reference voltages for the positive and negative half-cycles respectively. For example, the first detection module 101 can output a first detection signal to the control module 103 according to the first voltage and the first reference voltage; the second detection module 102 outputs a second detection signal to the control module 103 according to the second voltage and the second reference voltage; among them, the first reference voltage and the second reference voltage can be different.

[0044] In an embodiment of the present application, as Figure 2 shown, the first detection module 101 includes a first comparison unit 1011 and a first adjustment unit 1012. The first comparison unit 1011 is electrically connected to the first adjustment unit 1012 and the control module 103 respectively, and the first adjustment unit 1012 is electrically connected to the input end of the IGBT.

[0045] Specifically, the first adjustment unit 1012 outputs a first adjustment voltage to the first comparison unit 1011 according to the first voltage. The first comparison unit 1011 compares the first adjustment voltage with the reference voltage. If the first adjustment voltage is greater than the reference voltage, it indicates that the first voltage has increased sharply. At this time, it is characterized that a short-circuit fault has occurred in the positive half-cycle of the AC voltage. The first comparison unit 1011 outputs a first detection signal to the control module 103 so that the control module 103 controls all IGBTs to stop working.

[0046] In an embodiment of the present application, as Figure 2As shown in the figure, the first comparison unit 1011 includes a first operational amplifier U1, a first resistor R1, a second resistor R2, and a third resistor R3. The first input terminal of the first operational amplifier U1 is electrically connected to the first terminal of the second resistor R2. The second input terminal of the first operational amplifier U1 is electrically connected to the first terminal of the third resistor R3. The output terminal of the first operational amplifier U1 is electrically connected to the control module 103. The first terminal of the first resistor R1 is used to be electrically connected to the first power supply. The second terminal of the first resistor R1 is respectively electrically connected to the second terminal of the second resistor R2 and the first adjustment unit 1012. The second terminal of the third resistor R3 is used to receive a reference voltage. The first adjustment unit 1012 includes a first diode D1. The anode of the first diode D1 is respectively electrically connected to the second terminal of the first resistor R1 and the second terminal of the second resistor R2. The cathode of the first diode D1 is electrically connected to the input terminal of the IGBT.

[0047] Specifically, the first resistor R1 serves as a pull-up resistor and is used to pull up the voltage of the first input terminal (non-inverting input terminal) of the first operational amplifier U1 to the first power supply voltage when a short-circuit fault occurs in the positive half-cycle of the AC voltage. The second resistor R2 and the third resistor R3 are respectively connected to the two input terminals of the first operational amplifier U1 and are used for current limiting and impedance matching to ensure the stability of signal transmission. The first operational amplifier U1 is used to compare and amplify the voltages transmitted to the two input terminals and output a corresponding level signal according to the comparison result. When the voltage of the first input terminal is greater than the voltage of the second input terminal, the output terminal of the first operational amplifier U1 outputs a high-level signal. When the voltage of the first input terminal is less than the voltage of the second input terminal, the output terminal of the first operational amplifier U1 outputs a low-level signal. The first diode D1 plays a role of unidirectional conduction. When the difference between the anode voltage and the cathode voltage of the first diode D1 is greater than the conduction threshold voltage of the first diode D1, the first diode D1 conducts. Specifically, when no short-circuit fault occurs in the positive half-cycle of the AC voltage, the first voltage does not change sharply, and the first diode D1 is in a conducting state. The voltage of the first input terminal of the first operational amplifier U1 is not higher than the reference voltage of the second input terminal. At this time, the output terminal of the first operational amplifier U1 outputs a low-level signal. When a short-circuit fault occurs in the positive half-cycle of the AC voltage, the first voltage increases sharply, which causes the cathode voltage of the first diode D1 to increase sharply. At this time, the cathode voltage of the first diode D1 is higher than the anode voltage, and the first diode D1 changes from a conducting state to a cut-off state. At this time, the voltage of the first input terminal of the first operational amplifier U1 is pulled up to the first power supply voltage (+5V) by the first resistor R1. At this time, the voltage of the first input terminal of the first operational amplifier U1 is higher than the reference voltage received by the second input terminal, and the level signal output by the output terminal of the first operational amplifier U1 jumps from a low-level signal to a high-level signal.

[0048] It should be noted that only one component composition of the first detection module 101 is shown in this application, which does not mean that only this one component composition can achieve the function of the first detection module 101. Other components that can achieve this function can also be substituted, and are not limited thereto.

[0049] In an embodiment of the present application, as Figure 2 shown, the second detection module 102 includes a second comparison unit 1021 and a second adjustment unit 1022. The second comparison unit 1021 is electrically connected to the second adjustment unit 1022 and the control module 103 respectively, and the second adjustment unit 1022 is electrically connected to the output end of the IGBT.

[0050] Specifically, the second adjustment unit 1022 outputs a second adjustment voltage to the second comparison unit 1021 according to the second voltage. The second comparison unit 1021 compares the second adjustment voltage with the reference voltage. If the second adjustment voltage is greater than the reference voltage, it indicates that the second voltage has increased sharply and has exceeded the reference voltage. At this time, it represents that a short-circuit fault has occurred in the positive half cycle of the AC voltage. The second comparison unit 1021 outputs a second detection signal to the control module 103, so that the control module 103 controls all drive modules to turn off the output.

[0051] In an embodiment of the present application, as Figure 2 shown, the second comparison unit 1021 includes a second operational amplifier U2, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6. The first input terminal of the second operational amplifier U2 is electrically connected to the first end of the fifth resistor R5, the second input terminal of the second operational amplifier U2 is electrically connected to the first end of the sixth resistor R6, the output terminal of the second operational amplifier U2 is electrically connected to the control module 103, the first end of the fourth resistor R4 is used to be electrically connected to the second power supply, the second end of the fourth resistor R4 is respectively electrically connected to the second end of the fifth resistor R5 and the second adjustment unit 1022, and the second end of the sixth resistor R6 is used to receive the reference voltage; the second adjustment unit 1022 includes a second diode D2. The anode of the second diode D2 is respectively electrically connected to the second end of the fourth resistor R4 and the second end of the fifth resistor R5, and the cathode of the second diode D2 is electrically connected to the output end of the IGBT.

[0052] Specifically, the fourth resistor R4 serves as a pull-up resistor, which is used to pull up the voltage of the first input terminal (non-inverting input terminal) of the second operational amplifier U2 to the second power supply voltage when a short-circuit fault occurs in the negative half-cycle of the AC voltage. The fifth resistor R5 and the sixth resistor R6 are respectively connected to the two input terminals of the second operational amplifier U2, which are used for current limiting and impedance matching to ensure the stability of signal transmission. The second operational amplifier U2 is used to compare and amplify the voltages transmitted to the two input terminals, and output a corresponding level signal according to the comparison result. When the voltage of the first input terminal is greater than the voltage of the second input terminal, the output terminal of the second operational amplifier U2 outputs a high-level signal. When the voltage of the first input terminal is less than the voltage of the second input terminal, the output terminal of the second operational amplifier U2 outputs a low-level signal. The second diode D2 plays a role of unidirectional conduction. When the difference between the anode voltage and the cathode voltage of the second diode D2 is greater than the conduction threshold voltage of the second diode D2, the second diode D2 conducts. Specifically, when no short-circuit fault occurs in the negative half-cycle of the AC voltage, the second voltage does not change sharply, and the second diode D2 is in the conducting state. The voltage of the first input terminal of the second operational amplifier U2 is not higher than the reference voltage of the second input terminal. At this time, the output terminal of the second operational amplifier U2 outputs a low-level signal. When a short-circuit fault occurs in the negative half-cycle of the AC voltage, the second voltage increases sharply, so that the cathode voltage of the second diode D2 increases sharply. At this time, the cathode voltage of the second diode D2 is higher than the anode voltage, and the second diode D2 changes from the conducting state to the cut-off state. At this time, the voltage of the first input terminal of the second operational amplifier U2 is pulled up to the second power supply voltage (+5V) by the fourth resistor R4. At this time, the voltage of the first input terminal of the second operational amplifier U2 is higher than the reference voltage received by the second input terminal, and the level signal output by the output terminal of the second operational amplifier U2 jumps from a low-level signal to a high-level signal.

[0053] It should be noted that only one component composition of the second detection module 102 is shown in this application, which does not mean that only this one component composition can implement the function of the second detection module 102. Other components that can implement this function can also be replaced, and are not limited thereto.

[0054] In an embodiment of the present application, as Figure 3 shown, the IGBT protection circuit further includes a reference module 104. The reference module 104 is electrically connected to the first detection module 101 and the second detection module 102 respectively. The reference module 104 is used to output reference voltages to the first detection module 101 and the second detection module 102 respectively.

[0055] Specifically, the main function of the reference module 104 is to provide a stable and accurate reference voltage for the first detection module 101 and the second detection module 102. Since the first detection module 101 and the second detection module 102 need to compare the detected first voltage and second voltage with the reference voltage and output corresponding level signals, the control module 103 can determine whether a short circuit occurs based on these level signals. Therefore, as the reference point for comparison, the stability and accuracy of the reference voltage directly determine the measurement accuracy of the detection module.

[0056] It should be noted that the reference voltage is also used to set the trigger threshold for short-circuit protection. By adjusting the reference voltage, the action conditions of the IGBT protection circuit 10 can be flexibly configured, so as to achieve a fast response and precise control of short-circuit faults.

[0057] In an embodiment of the present application, as Figure 2 shown, the reference module 104 includes a third operational amplifier U3, a fifteenth resistor R15, a sixteenth resistor R16, and a seventeenth resistor R17. The first input terminal of the third operational amplifier U3 is electrically connected to the first end of the fifteenth resistor R15. The second input terminal of the third operational amplifier U3 is electrically connected to the first end of the sixteenth resistor R16. The output terminal of the third operational amplifier U3 is respectively electrically connected to the second end of the sixteenth resistor R16, the first detection module 101, and the second detection module 102. The first end of the seventeenth resistor R17 is respectively electrically connected to the second end of the fifteenth resistor R15 and the third power supply. The second end of the seventeenth resistor R17 is grounded.

[0058] Specifically, the fifteenth resistor R15 can perform voltage division processing on the voltage signal of the third power supply and input a voltage signal with an appropriate ratio to the first input terminal of the third operational amplifier U3. The sixteenth resistor R16 and the third operational amplifier U3 form a feedback loop, and its function is to feedback a part of the signal output by the third operational amplifier U3 back to the second input terminal. Through this feedback mechanism, the output of the third operational amplifier U3 can be stabilized, and the reliability of the reference module 104 can be improved. The seventeenth resistor R17 mainly plays the role of shunting and stabilizing the voltage. By introducing a part of the current into the ground, it can ensure that the voltage signal input to the first input terminal of the third operational amplifier U3 is more stable and reduce the influence of factors such as power supply fluctuations on the input signal. The seventeenth resistor R17 cooperates with the fifteenth resistor R15 to jointly perform voltage division on the voltage (+5V) of the third power supply, provide an appropriate input signal for the input terminal of the third operational amplifier U3, and to a certain extent protect other devices in the circuit from being impacted by excessive voltage or current. The third operational amplifier U3 is used to compare, amplify, etc. the two input signals and output a stable and reliable reference voltage signal at the output terminal.

[0059] It should be noted that only one component composition of the reference module 104 is shown in this application, which does not mean that only this one component composition can realize the function of the reference module 104. Other components that can realize this function can also be replaced, and are not limited thereto.

[0060] This application also discloses a power supply device, including an IGBT and the above-mentioned IGBT protection circuit 10. The input end of the IGBT is electrically connected to the first detection module 101 in the IGBT protection circuit 10, the output end of the IGBT is electrically connected to the second detection module 102 in the IGBT protection circuit 10, and the control end of the IGBT is electrically connected to the control module 103 in the IGBT protection circuit 10. By adopting the above-mentioned IGBT protection circuit 10, the power supply device can respond quickly when a short circuit occurs in the positive or negative half cycle of the AC voltage, thereby effectively preventing the short circuit from damaging the circuit and equipment. The power supply device provided by this application plays an important role in key links such as power plants, substations, transmission lines, and distribution networks in the power system. It can quickly cut off the electrical connection between the fault area and the normal area, thereby reducing the impact of the fault on the power system and improving the stability of the power system. In addition, the power supply device can also be widely applied to fields such as new energy vehicle charging, building electricity use places, industrial production fields, and new energy power generation systems.

[0061] Since the processing and functions realized by the power supply device in this embodiment are basically corresponding to the embodiments, principles, and examples of the foregoing IGBT protection circuit, for the details not described in the description of this embodiment, reference can be made to the relevant descriptions in the foregoing embodiments and will not be elaborated here.

[0062] The above-described embodiments are only used to illustrate the technical solutions of this application, rather than to limit them; although this application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included in the protection scope of this application.

Claims

1. An IGBT protection circuit, characterized in that, It includes a first detection module, a second detection module and a control module. The control module is electrically connected to the first detection module and the second detection module respectively. The first detection module is electrically connected to the input end of the IGBT. The second detection module is electrically connected to the output end of the IGBT. The control module is electrically connected to the control end of the IGBT; The first detection module is used to detect the first voltage at the input end of the IGBT and output a first detection signal to the control module according to the first voltage and a reference voltage. The control module is used to determine whether the first voltage is abnormal according to the first detection signal, and output a first control signal to the control end of the IGBT when the first voltage is abnormal. The first control signal is used to instruct the IGBT to stop working. The second detection module is used to detect the second voltage at the output end of the IGBT and output a second detection signal to the control module according to the second voltage and the reference voltage. The control module is also used to determine whether the second voltage is abnormal according to the second detection signal, and output a second control signal to the control end of the IGBT when the second voltage is abnormal. The second control signal is used to instruct the IGBT to stop working.

2. The IGBT protection circuit according to claim 1, wherein The first detection module includes a first comparison unit and a first adjustment unit. The first comparison unit is electrically connected to the first adjustment unit and the control module respectively. The first adjustment unit is electrically connected to the input end of the IGBT; The first adjustment unit is used to output a first adjustment voltage to the first comparison unit according to the first voltage. The first comparison unit is used to output the first detection signal to the control module when the first adjustment voltage is greater than the reference voltage.

3. The IGBT protection circuit according to claim 2, wherein The first comparison unit includes a first operational amplifier, a first resistor, a second resistor and a third resistor. The first input end of the first operational amplifier is electrically connected to the first end of the second resistor. The second input end of the first operational amplifier is electrically connected to the first end of the third resistor. The output end of the first operational amplifier is electrically connected to the control module. The first end of the first resistor is used to be electrically connected to a first power supply. The second end of the first resistor is respectively electrically connected to the second end of the second resistor and the first adjustment unit. The second end of the third resistor is used to receive the reference voltage.

4. The IGBT protection circuit according to claim 3, wherein The first adjustment unit includes a first diode. The anode of the first diode is respectively electrically connected to the second end of the first resistor and the second end of the second resistor. The cathode of the first diode is electrically connected to the input end of the IGBT.

5. The IGBT protection circuit according to claim 1, wherein The second detection module includes a second comparison unit and a second adjustment unit. The second comparison unit is electrically connected to the second adjustment unit and the control module respectively. The second adjustment unit is electrically connected to the output end of the IGBT; The second adjustment unit is used to output a second adjustment voltage to the second comparison unit according to the second voltage. The second comparison unit is used to output the second detection signal to the control module when the second adjustment voltage is greater than the reference voltage.

6. The IGBT protection circuit according to claim 5, characterized in that, The second comparison unit includes a second operational amplifier, a fourth resistor, a fifth resistor, and a sixth resistor. The first input terminal of the second operational amplifier is electrically connected to the first end of the fifth resistor. The second input terminal of the second operational amplifier is electrically connected to the first end of the sixth resistor. The output terminal of the second operational amplifier is electrically connected to the control module. The first end of the fourth resistor is used to be electrically connected to a second power supply. The second end of the fourth resistor is respectively electrically connected to the second end of the fifth resistor and the second adjustment unit. The second end of the sixth resistor is used to receive the reference voltage.

7. The IGBT protection circuit according to claim 6, characterized in that, The second adjustment unit includes a second diode. The anode of the second diode is respectively electrically connected to the second end of the fourth resistor and the second end of the fifth resistor. The cathode of the second diode is electrically connected to the output terminal of the IGBT.

8. The IGBT protection circuit according to any one of claims 1-7, characterized in that, The IGBT protection circuit further includes a reference module. The reference module is respectively electrically connected to the first detection module and the second detection module. The reference module is used to output the reference voltage to the first detection module and the second detection module respectively.

9. The IGBT protection circuit according to claim 8, wherein, The reference module includes a third operational amplifier, a fifteenth resistor, a sixteenth resistor, and a seventeenth resistor. The first input terminal of the third operational amplifier is electrically connected to the first end of the fifteenth resistor. The second input terminal of the third operational amplifier is electrically connected to the first end of the sixteenth resistor. The output terminal of the third operational amplifier is respectively electrically connected to the second end of the sixteenth resistor, the first detection module, and the second detection module. The first end of the seventeenth resistor is respectively electrically connected to the second end of the fifteenth resistor and a third power supply. The second end of the seventeenth resistor is grounded.

10. A power supply device, characterized in that, It includes an IGBT and the IGBT protection circuit according to any one of claims 1-9. The input terminal of the IGBT is electrically connected to the first detection module in the IGBT protection circuit. The output terminal of the IGBT is electrically connected to the second detection module in the IGBT protection circuit. The control terminal of the IGBT is electrically connected to the control module in the IGBT protection circuit.

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