IGBT protection device, air conditioner and IGBT protection method thereof

Abstract

The present invention discloses an IGBT protection device, an air conditioner, and an IGBT protection method thereof. The device comprises: a main control module, which, upon receiving a set level signal output by a logic determination module, stops sending PWM switching signals to a driver module and simultaneously sends a control signal to a driver power conversion module; a driver power conversion module, upon receiving a control signal from the main control module, provides a negative voltage to the driver module; a driver module, upon receiving a control signal from the main control module, stops outputting PWM signals to the IGBT, causing the IGBT to hard-off; and, upon receiving a negative voltage, outputs a negative shutdown signal, causing the IGBT to negatively shut down. This solution determines whether an IGBT is faulty by combining the voltage, current, and temperature of the IGBT, and performs negative voltage shutdown when an IGBT fails, thereby preventing the IGBT from being mis-turned on, thereby improving reliability and safety.

Description

Technical Field

[0001] The present invention belongs to the field of IGBT protection technology, and specifically relates to an IGBT protection device, an air conditioner and an IGBT protection method thereof, and more particularly to an IGBT fault detection and reliable shutdown device, an air conditioner and an IGBT protection method thereof. Background Art

[0002] With the development of the manufacturing industry, power devices (such as power control devices) are increasingly used in various fields. Among them, the high-voltage and high-power power control device IGBT has become extremely important in the power control field. Therefore, the protection of power control device IGBT has become particularly important.

[0003] In products with IGBT power control devices (such as air conditioners), when a short circuit occurs in the high-voltage circuit controlled by the IGBT, the current Ic flowing through the collector (C) and emitter (E) of the IGBT increases dramatically, causing the power loss of the IGBT to also increase dramatically, causing the IGBT to heat up severely. If the IGBT is not quickly turned off at this time, the IGBT will suffer thermal breakdown due to overheating, resulting in breakdown and damage to the IGBT.

[0004] However, since the gate (G) of the IGBT has a capacitive input impedance, the IGBT is very sensitive to the charge accumulation on the gate (G). When the IGBT is turned off, if the current amplitude in the IGBT is large, the self-induced electromotive force Ldi / dt generated is too high, and a very high spike voltage will be generated at both ends of the collector (C) and emitter (E) of the IGBT. At the same time, there will be a burr spike in the gate (G) voltage of the IGBT, which will cause the IGBT to be mis-turned on.

[0005] The above content is only used to assist in understanding the technical solution of the present invention and does not constitute an admission that the above content is prior art. Summary of the Invention

[0006] The object of the present invention is to provide an IGBT protection device, an air conditioner and an IGBT protection method thereof, so as to solve the problem that when the IGBT is turned off, if the current amplitude in the IGBT is large, the self-induced electromotive force Ldi / dt generated is too high, a very high spike voltage is generated at both ends of the collector (C) and emitter (E) of the IGBT, and at the same time, there are burrs in the gate (G) voltage of the IGBT, thereby causing the IGBT to be mis-turned on. By combining the voltage, current and temperature of the IGBT to determine whether the IGBT is faulty, and performing negative voltage shutdown when the IGBT fails, the IGBT can be reliably turned off and mis-turned on of the IGBT can be avoided, which is beneficial to improving the reliability and safety of IGBT protection.

[0007] The present invention provides an IGBT protection device, comprising: a voltage sampling module, a current sampling module, a temperature sampling module, a logic judgment module, a driving power conversion module, a driving module and a main control module; wherein the voltage sampling module is arranged at the collector of the IGBT, and is used to detect the voltage across the collector and emitter of the IGBT, which is recorded as the detection voltage of the IGBT; the current sampling module is arranged at the emitter of the IGBT, and is used to detect the current between the collector and emitter of the IGBT, which is recorded as the detection current of the IGBT; the temperature sampling module is arranged in the heat dissipation area of ​​the IGBT, and is used to detect the temperature of the IGBT, which is recorded as the detection temperature of the IGBT; the input end of the logic judgment module is respectively connected to the voltage sampling module, the current sampling module and the temperature sampling module; the output end of the logic judgment module is respectively connected to the main control module and the driving module; the logic judgment module is used to detect when the detection voltage of the IGBT is greater than the set voltage and the detection current of the IGBT is greater than the set The main control module is connected to the driving power conversion module and the driving module respectively, and is used to stop sending the PWM switching signal to the driving module and send a control signal to the driving power conversion module at the same time when receiving the setting level signal output by the logic judgment module; the control signal is a signal for controlling the driving power conversion module to make the IGBT negative voltage shut down; the driving power conversion module is connected to the driving module and is used to provide a negative voltage to the driving module when receiving the control signal sent by the main control module; the driving module is connected to the gate of the IGBT and is used to stop outputting the PWM signal to the IGBT when the main control module stops sending the PWM switching signal to the driving module, so as to make the IGBT hard shut down; and, when receiving the negative voltage provided by the driving power conversion module, output a negative shutdown signal to the IGBT to make the IGBT negative voltage shut down.

[0008] In some embodiments, it further includes: an inductor module, a diode module and a capacitor module; the voltage sampling module includes: a first voltage-dividing resistor module and a second voltage-dividing resistor module; wherein, the input voltage is connected to the collector of the IGBT and the anode of the diode module respectively after passing through the inductor module; the cathode of the diode module is grounded after passing through the capacitor module; the cathode of the diode module is also grounded after passing through the first voltage-dividing resistor module and the second voltage-dividing resistor module; the common end of the first voltage-dividing resistor module and the second voltage-dividing resistor module serves as the output end of the voltage sampling module, for outputting the detection voltage of the IGBT.

[0009] In some embodiments, the current sampling module includes: a sampling resistor module; the temperature sampling module includes: a thermistor module; wherein the sampling resistor module is arranged between the emitter of the IGBT and the ground; the end of the sampling resistor module away from the emitter of the IGBT is used to output the detection current of the IGBT.

[0010] In some embodiments, the logic judgment module includes: a first comparison module, a second comparison module, a third comparison module, and an AND logic module; wherein the first input terminal of the first comparison module is used to input the detection voltage of the IGBT; the second input terminal of the first comparison module is used to input a set voltage; when the detection voltage of the IGBT is greater than the set voltage, the first comparison module outputs a first level signal to the first input terminal of the AND logic module; the first input terminal of the second comparison module is used to input the detection current of the IGBT; the second input terminal of the second comparison module is used to input the set current; when the detection current of the IGBT is greater than the set current, the second comparison module outputs a first level signal to the first input terminal of the AND logic module. The first input terminal of the third comparison module is used to input the detection temperature of the IGBT; the second input terminal of the third comparison module is used to input a set temperature; when the detection temperature of the IGBT is greater than the set temperature, the third comparison module outputs the first level signal to the third input terminal of the AND logic module; the output terminal of the AND logic module is used to output the set level signal as a signal of the IGBT fault when the first input terminal of the AND logic module receives the first level signal, the second input terminal of the AND logic module receives the first level signal, and the third input terminal of the AND logic module receives the first level signal.

[0011] In some embodiments, the driving power conversion module includes: a first switch module, a second switch module, a third switch module, a fourth switch module, a current limiting resistor module, a negative voltage module and a power conversion module; wherein the negative pole of the DC power supply is grounded; the positive pole of the DC power supply is connected to the first input end of the driving module after passing through the first switch module and the power conversion module, and is used to provide the first voltage signal to the driving module when the first switch module is turned on; the positive pole of the DC power supply is also connected to the second input end of the driving module after passing through the second switch module, the current limiting resistor module, the third switch module and the power conversion module, and is used to provide the second voltage signal to the driving module when the first switch module is disconnected and the second switch module and the third switch module are both turned on. two voltage signals; and, when the first switch module, the second switch module and the third switch module are all disconnected, providing a 0 voltage signal to the driving module to stop sending the PWM switching signal to the driving module; the voltage of the second voltage signal is less than the voltage of the first voltage signal; wherein, the positive pole of the DC power supply is connected to the third input end of the driving module after passing through the second switch module and the current limiting resistor module, and also after passing through the fourth switch module, the negative pressure module and the power conversion module, and is used to provide a negative voltage to the driving module when the first switch module and the third switch module are disconnected and the second switch module and the fourth switch module are connected, so that the driving module outputs a negative shutdown signal to the IGBT, so that the IGBT is negatively shut down.

[0012] In some embodiments, the driving power conversion module further includes: a voltage regulator diode module; wherein the second switch module is connected to the cathode of the voltage regulator diode module after passing through the current limiting resistor module; the anode of the voltage regulator diode module is grounded; the cathode of the voltage regulator diode module is connected to the second input end of the driving module after passing through the third switch module and the power conversion module; the cathode of the voltage regulator diode module is also connected to the third input end of the driving module after passing through the fourth switch module and the negative pressure module.

[0013] In some embodiments, the device further includes: a driving resistance module; the driving resistance module is arranged between the driving module and the gate of the IGBT.

[0014] Matching the above device, the present invention further provides an air conditioner, comprising: the above-mentioned IGBT protection device.

[0015] In accordance with the above-mentioned air conditioner, the present invention provides an IGBT protection method for an air conditioner, comprising: obtaining the voltage across the collector and emitter of the IGBT, which is recorded as the detection voltage of the IGBT; obtaining the current between the collector and emitter of the IGBT, which is recorded as the detection current of the IGBT; and obtaining the temperature of the IGBT, which is recorded as the detection temperature of the IGBT; outputting a set level signal when the detection voltage of the IGBT is greater than a set voltage, the detection current of the IGBT is greater than a set current, and the detection temperature of the IGBT is greater than a set temperature; and stopping sending a set level signal to the driving module when the set level signal is received. PWM switching signal, and simultaneously sends a control signal to the driving power conversion module; the control signal is a signal for controlling the driving power conversion module to make the IGBT negative voltage shut down; wherein, when the PWM switching signal is stopped from being sent to the driving module, the driving module stops outputting the PWM signal to the IGBT, so that the IGBT is hard-turned off; the driving power conversion module provides a negative voltage to the driving module when receiving the control signal; wherein, when the negative voltage provided by the driving power conversion module is received, the driving module outputs a negative shutdown signal to the IGBT, so that the IGBT is negative voltage shut down.

[0016] In some embodiments, when the driving power conversion module includes a first switch module, a second switch module, a third switch module, a fourth switch module, a current limiting resistor module, a negative pressure module and a power conversion module: if the control signal is not received, the first switch module is controlled to be turned on, and the second switch module, the third switch module and the fourth switch module are controlled to be turned off; if the control signal is received, the driving module is controlled to provide a negative voltage to output a negative shutdown signal to the IGBT to cause the IGBT to be negatively shut down, specifically including: at a first set time, the first switch module is controlled to be turned off, and the second switch module and the third switch module are controlled to be turned off. The first switch module, the second switch module and the third switch module are all turned on, and the fourth switch module is controlled to continue to be turned off, so as to provide a second voltage signal to the driving module; at a second set time, the first switch module, the second switch module and the third switch module are all controlled to be turned off, and the fourth switch module is controlled to continue to be turned off, so as to provide a 0 voltage signal to the driving module to stop sending a PWM switching signal to the driving module; at a third set time, the second switch module and the fourth switch module are all controlled to be turned on, and the first switch module and the third switch module are controlled to continue to be turned off, so as to provide a negative voltage to the driving module, so that the driving module outputs a negative shutdown signal to the IGBT, so that the IGBT is turned off by negative pressure.

[0017] Therefore, the solution of the present invention is to set a driving power conversion module between the main control chip and the driving module of the IGBT, and set a normal power supply module and a negative voltage shutdown module in the driving power conversion module; when the IGBT is working, detect the voltage across the collector (C) and the emitter (E) of the IGBT, the current Ic between the collector (C) and the emitter (E) of the IGBT, and the temperature of the IGBT; judge the IGBT through the logic judgment module based on the detected voltage across the collector (C) and the emitter (E), the current Ic between the collector (C) and the emitter (E), and the temperature of the IGBT. Whether it is faulty; when the logic judgment module outputs a signal of IGBT fault, the driving module stops sending PWM signals to the IGBT to make the IGBT hard-turn off, the main control chip stops sending PWM switching signals to the driving module and sends a control signal to the driving power conversion module at the same time, so that the driving power conversion module uses negative pressure to turn off the IGBT through the driving module, and performs double shut-off on the IGBT in the event of an IGBT fault. Thus, by combining the voltage, current and temperature of the IGBT to determine whether the IGBT is faulty, and performing negative pressure shutdown when the IGBT fails, the IGBT can be reliably shut down to avoid mis-turning on of the IGBT, which is beneficial to improving the reliability and safety of IGBT protection.

[0018] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention.

[0019] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of an embodiment of an IGBT protection device of the present invention;

[0021] Figure 2 A schematic structural diagram of an embodiment of an IGBT fault detection topology of the present invention;

[0022] Figure 3 1 is a schematic structural diagram of an embodiment of an IGBT fault detection circuit of the present invention;

[0023] Figure 4 Schematic diagram of the structure of an embodiment of a negative voltage shutdown circuit after an IGBT fault in an IGBT fault detection circuit of the present invention;

[0024] Figure 5 Schematic diagram of the structure of the optimal embodiment of the IGBT fault detection circuit of the present invention;

[0025] Figure 6A schematic diagram showing how the turn-off voltage of an IGBT in an IGBT fault detection circuit of the present invention changes over time;

[0026] Figure 7 1 is a schematic structural diagram of another embodiment of an IGBT fault detection circuit of the present invention;

[0027] Figure 8 1. A flow chart of an embodiment of an IGBT protection method for an air conditioner according to the present invention;

[0028] Figure 9 FIG. 1 is a flow chart of an embodiment of the method for controlling negative voltage shutdown of an IGBT in the present invention. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] Considering that, in the relevant schemes, the only protection for IGBT is overcurrent protection, that is, overcurrent protection is performed by detecting the current Ic between the collector (C) and emitter (E) of the IGBT, and when an overcurrent fault occurs in the IGBT, the IGBT is directly turned off. When the IGBT is turned off, if the current amplitude in the IGBT is large, the self-induced electromotive force Ldi / dt generated is too high, and a very high spike voltage will be generated at both ends of the collector (C) and emitter (E) of the IGBT. At the same time, there will be a burr spike in the gate (G) voltage of the IGBT, which will cause the IGBT to be mis-turned on.

[0031] Therefore, the solution of the present invention proposes an IGBT protection device, specifically an IGBT fault detection and reliable shutdown device, which determines whether the IGBT is faulty by detecting the voltage across the collector (C) and emitter (E) of the IGBT, the current Ic between the collector (C) and emitter (E) of the IGBT, and the temperature of the IGBT. When it is determined that the IGBT is faulty, a negative pressure reliable shutdown is performed by driving the power conversion module to avoid the IGBT from being mis-turned on when shutting down the IGBT.

[0032] According to an embodiment of the present invention, an IGBT protection device is provided. Figure 1 The schematic diagram of the structure of an embodiment of the device of the present invention is shown. The IGBT protection device may include: a voltage sampling module, a current sampling module, a temperature sampling module, a logic determination module, a driving power conversion module, a driving module and a main control module.

[0033] The voltage sampling module is provided at the collector of the IGBT and is used to detect the voltage across the collector and emitter of the IGBT, which is recorded as the detected voltage of the IGBT. The current sampling module is provided at the emitter of the IGBT and is used to detect the current between the collector and emitter of the IGBT, which is recorded as the detected current of the IGBT. The temperature sampling module is provided in the heat dissipation area of ​​the IGBT and is used to detect the temperature of the IGBT, which is recorded as the detected temperature of the IGBT.

[0034] The input end of the logic judgment module is respectively connected to the voltage sampling module, the current sampling module and the temperature sampling module, specifically, respectively connected to the output end of the voltage sampling module, the output end of the current sampling module, and the output end of the temperature sampling module; the output end of the logic judgment module is respectively connected to the main control module and the driving module; the logic judgment module is used to output a set level signal, such as a high level signal, when the detection voltage of the IGBT is greater than the set voltage, the detection current of the IGBT is greater than the set current, and the detection temperature of the IGBT is greater than the set temperature.

[0035] The main control module is connected to the driving power conversion module and the driving module, respectively. Specifically, the output end of the main control module is connected to the driving power conversion module and the driving module, respectively. The main control module is used to stop sending the PWM switching signal to the driving module and send a control signal to the driving power conversion module when receiving the set level signal output by the logic judgment module. The control signal is a signal used to control the driving power conversion module to enable the IGBT to be negatively voltage-shutdown.

[0036] The driving power conversion module is connected to the driving module and is used to provide a negative voltage to the driving module when receiving a control signal sent by the main control module.

[0037] The driving module is connected to the gate of the IGBT and is used to stop outputting the PWM signal to the IGBT when the main control module stops sending the PWM switching signal to the driving module, so as to hard-turn off the IGBT; and, when receiving the negative voltage provided by the driving power conversion module, output a negative shutdown signal to the IGBT, so as to cause the IGBT to be negatively shut down.

[0038] Specifically, Figure 2 FIG. 1 is a schematic diagram showing a structure of an embodiment of an IGBT fault detection topology of the present invention. Figure 2As shown in Figure 1, the IGBT fault detection topology includes a temperature detection module, a voltage sampling module, a current detection module, a logic determination module, a main control module, a drive power conversion module, and a drive module. The voltage sampling module can detect voltage using a voltage divider resistor or a voltage sensor. The current detection module can detect current using a sampling resistor through an op amp or a current sensor. The temperature detection module can detect temperature using a temperature sensor or a temperature sensor.

[0039] like Figure 2 As shown, the first output end of the temperature detection module is connected to the first input end of the logic judgment module; the second output end of the temperature detection module is connected to the first input end of the main control module. The first output end of the voltage sampling module is connected to the second input end of the logic judgment module; the second output end of the voltage sampling module is connected to the second input end of the main control module; the first output end of the current detection module is connected to the third input end of the logic judgment module; the second output end of the current detection module is connected to the third input end of the main control module. The first output end of the logic judgment module is connected to the first input end of the driver module. The second output end of the logic judgment module is connected to the fourth input end of the main control module. The first output end of the main control module is connected to the input end of the driving power conversion module; the output end of the driving power conversion module is connected to the second input end of the driver module. The second output end of the main control module is connected to the third input end of the driver module. The output end of the driver module is connected to the gate (G) of the IGBT.

[0040] exist Figure 2 In the example shown, the voltage sampling module detects the voltage across the IGBT's collector (C) and emitter (E), compares it with the set voltage, and obtains a voltage comparison result. This voltage comparison result is then fed into the logic decision module. The current detection module detects the current Ic flowing between the IGBT's collector (C) and emitter (E), compares it with the set current, and obtains a current comparison result. This current comparison result is then fed into the logic decision module. The temperature detection module detects the IGBT's temperature, compares it with the set temperature, and obtains a temperature comparison result. This temperature comparison result is then fed into the logic decision module.

[0041] exist Figure 2In the example shown, after the voltage comparison result, the current comparison result, and the temperature comparison result are all input into the logic judgment module, when the voltage sampling module detects that the voltage across the collector (C) and emitter (E) of the IGBT exceeds the set voltage, the current Ic between the collector (C) and emitter (E) of the IGBT exceeds the set current, and the temperature of the IGBT exceeds the set temperature, the logic judgment module determines that the IGBT is faulty and sends IGBT fault signals to the drive module and the main control module, respectively.

[0042] After receiving the IGBT fault signal from the logic judgment module, the driver module stops sending PWM signals to hard-shut down the IGBT. After receiving the IGBT fault signal from the logic judgment module, the main control module stops sending PWM switching signals to the driver module and simultaneously sends a shutdown signal to the driver power conversion module to control the IGBT to perform negative voltage shutdown. The logic judgment module is directly connected to the driver module. Its purpose is that after the logic judgment unit determines a fault, it can directly send a signal to the driver module to start shutting down, without having to go through the logic judgment module, the main chip MCU, and then to the driver module, thus improving the timeliness and reliability of control. As a result, the IGBT will not be mis-turned on during shutdown, making the IGBT shutdown more reliable during faults and ensuring the reliability and safety of IGBT protection.

[0043] In this way, the solution of the present invention provides an IGBT fault detection and reliable shutdown device thereof, specifically a new type of IGBT fault detection topology, which determines whether the IGBT is faulty by detecting the voltage across the collector (C) and emitter (E) of the IGBT, the current Ic between the collector (C) and emitter (E) of the IGBT, and the temperature of the IGBT. When it is determined that the IGBT is faulty, a negative pressure reliable shutdown is performed by driving the power conversion module to prevent the IGBT from being mis-turned on due to the spike voltage, thereby avoiding the IGBT from being mis-turned on when the IGBT is turned off.

[0044] In some embodiments, the IGBT protection device described in the solution of the present invention further includes: an inductor module, a diode module and a capacitor module, the inductor module is such as the inductor L1, the diode module is such as the diode D2, and the capacitor module is such as the capacitor C1; the voltage sampling module includes: a first voltage-dividing resistor module and a second voltage-dividing resistor module, the first voltage-dividing resistor module is such as the resistor R4, and the second voltage-dividing resistor module is such as the resistor R5.

[0045] Among them, the input voltage is connected to the collector of the IGBT and the anode of the diode module after passing through the inductor module; the cathode of the diode module is grounded after passing through the capacitor module; the cathode of the diode module is also grounded after passing through the first voltage-dividing resistor module and the second voltage-dividing resistor module; the common end of the first voltage-dividing resistor module and the second voltage-dividing resistor module serves as the output end of the voltage sampling module, which is used to output the detection voltage of the IGBT.

[0046] Specifically, Figure 5 FIG. 1 is a schematic diagram showing the structure of the optimal embodiment of the IGBT fault detection circuit of the present invention. Figure 5 As shown, the voltage sampling module includes resistors R4 and R5, which form a voltage divider resistor module. The cathode of diode D1 is connected to ground after passing through resistors R4 and R5. The common terminal of resistors R4 and R5 serves as the output terminal of the voltage sampling module.

[0047] In some embodiments, the IGBT protection device described in the solutions of the present invention comprises a current sampling module including a sampling resistor module, such as sampling resistor Rs; and a temperature sampling module including a thermistor module. The sampling resistor module is disposed between the emitter of the IGBT and ground; the end of the sampling resistor module, distal from the emitter of the IGBT, is configured to output the detection current of the IGBT.

[0048] Among them, the voltage sampling module can be implemented by resistors, sensors or other circuits, the current sampling module can be implemented by resistors, precision current sensors or other circuits, and the driving power conversion module can be implemented by other circuits.

[0049] In some embodiments, the logic judgment module includes: a first comparison module, a second comparison module, a third comparison module, and an AND logic module, the first comparison module is such as comparator U1, the second comparison module is such as comparator U2, the third comparison module is such as comparator U4, and the AND logic module is such as AND logic chip U3; wherein each comparator can be implemented using logic gates, operational amplifiers or other similar functional chips.

[0050] The first input terminal of the first comparison module is used to input the detection voltage of the IGBT; the second input terminal of the first comparison module is used to input a set voltage; if the detection voltage of the IGBT is greater than the set voltage, the first comparison module outputs a first level signal to the first input terminal of the AND logic module. The first input terminal of the second comparison module is used to input the detection current of the IGBT; the second input terminal of the second comparison module is used to input the set current; if the detection current of the IGBT is greater than the set current, the second comparison module outputs a first level signal to the second input terminal of the AND logic module. The first input terminal of the third comparison module is used to input the detection temperature of the IGBT; the second input terminal of the third comparison module is used to input the set temperature; if the detection temperature of the IGBT is greater than the set temperature, the third comparison module outputs a first level signal to the third input terminal of the AND logic module.

[0051] The output end of the AND logic module is used to output the set level signal as a signal of the IGBT fault when the first input end of the AND logic module receives the first level signal, the second input end of the AND logic module receives the first level signal, and the third input end of the AND logic module receives the first level signal.

[0052] Specifically, Figure 3 FIG. 1 is a schematic structural diagram of an embodiment of an IGBT fault detection circuit of the present invention. Figure 3 As shown, the IGBT fault detection circuit includes: a voltage sampling module, a current sampling module, a temperature sampling module, comparators U1, U2, U4, a main chip MCU, a logic chip U3, a sampling resistor Rs, an inductor L1, a diode D1, a capacitor C1, and an IGBT.

[0053] The input voltage Vin, after passing through inductor L1, is connected to the collector (C) of the IGBT. After passing through inductor L1, the input voltage Vin is also connected to the anode of diode D1; the cathode of diode D1 outputs voltage VP. The cathode of diode D1 is connected to ground after passing through capacitor C1; the emitter (E) of the IGBT is connected to ground after passing through sampling resistor Rs. The cathode of diode D1, after passing through the voltage sampling module, outputs the sampled voltage to the sampling voltage input of comparator U1 and the first input of the MCU. The output of comparator U1 is connected to the first input of logic chip U3. The end of sampling resistor Rs, away from the emitter (E) of the IGBT, passes through the current sampling module and outputs the sampled current to the sampling current input of comparator U2 and the second input of the MCU. The output of comparator U2 is connected to the second input of logic chip U3. The emitter (E) of the IGBT, after passing through the temperature sampling module, outputs the sampled temperature to the sampling temperature input of comparator U4 and the third input of the MCU. The output terminal of the logic chip U3 is connected to the fourth input terminal of the MCU.

[0054] In some embodiments, the IGBT protection device described in the solution of the present invention, the driving power conversion module includes: a first switch module, a second switch module, a third switch module, a fourth switch module, a current limiting resistor module, a negative pressure module and a power conversion module, the first switch module such as switch K1, the second switch module such as switch K2, the third switch module such as switch K3, the fourth switch module such as switch K4, the current limiting resistor module such as resistor R1, the negative pressure module such as negative power supply, and the power conversion module such as voltage conversion chip or voltage stabilizing chip.

[0055] The negative electrode of the DC power supply is grounded; the positive electrode of the DC power supply is connected to the first input terminal of the driving module after passing through the first switching module and the power conversion module, and is used to provide a first voltage signal, such as VCC(t1), to the driving module when the first switching module is turned on.

[0056] The positive electrode of the DC power supply is further connected to the second input end of the driving module after passing through the second switch module, the current limiting resistor module, the third switch module, and the power conversion module, and is used to provide a second voltage signal, such as VCC(t2), to the driving module when the first switch module is disconnected and the second switch module and the third switch module are both connected; and to provide a 0 voltage signal to the driving module to stop sending the PWM switching signal to the driving module when the first switch module, the second switch module, and the third switch module are all disconnected; the voltage of the second voltage signal is lower than the voltage of the first voltage signal.

[0057] The positive electrode of the DC power supply is connected to the third input terminal of the driving module after passing through the second switch module and the current limiting resistor module, and also passing through the fourth switch module, the negative pressure module and the power conversion module. The positive electrode of the DC power supply is used to provide a negative voltage to the driving module when the first switch module and the third switch module are disconnected and the second switch module and the fourth switch module are connected, so that the driving module outputs a negative shutdown signal to the IGBT, causing the IGBT to be negatively shut down.

[0058] Specifically, if Figure 3 As shown, the IGBT fault detection circuit also includes: switch K1, switch K2, switch K3, switch K4, current limiting resistor R1, and diode D1. The negative pole of the power supply VCC is grounded; the positive pole of the power supply VCC is connected to the first connection terminal of the switch K1. The second connection terminal of the switch K1 is connected to the first input terminal of the driver module, namely the VCC(t1) terminal. The positive pole of the power supply VCC is also connected to the first connection terminal of the switch K2; the second connection terminal of the switch K2 is connected to the cathode of the voltage-stabilizing diode D2 after passing through the current-limiting resistor R1; the anode of the voltage-stabilizing diode D2 is grounded. The positive pole of the power supply VCC is also connected to the first connection terminal of the switch K2; the second connection terminal of the switch K2 is connected to the first connection terminal of the switch K3 after passing through the current-limiting resistor R1; the second connection terminal of the switch K3 is connected to the second input terminal of the driver module, namely the VCC(t2) terminal. The positive terminal of the power supply VCC is also connected to the first connection terminal of switch K2; the second connection terminal of switch K2 is connected to the first connection terminal of switch K4 after passing through the current-limiting resistor R1; the second connection terminal of switch K4 is connected to the input terminal of the negative pressure module; and the output terminal of the negative pressure module is connected to the third input terminal of the driver module, namely the VCC (t3) terminal. The output terminal of the driver module is connected to the gate (G) of the IGBT after passing through the resistor R2. The first output terminal of the MCU is connected to the control terminal of switch K1. The second output terminal of the MCU is connected to the control terminal of switch K2. The third output terminal of the MCU is connected to the control terminal of switch K3. The fourth output terminal of the MCU is connected to the control terminal of switch K4. The fourth output terminal of the MCU can output a PWM signal to the fourth input terminal of the driver module.

[0059] In some embodiments, the driving power conversion module further includes a Zener diode module, such as a Zener diode D2. The second switch module is connected to the cathode of the Zener diode module via the current-limiting resistor module; the anode of the Zener diode module is grounded; the cathode of the Zener diode module is connected to the second input terminal of the driving module via the third switch module and the power conversion module; and the cathode of the Zener diode module is further connected to the third input terminal of the driving module via the fourth switch module and the negative voltage module.

[0060] Specifically, Figure 4 FIG. 1 is a schematic structural diagram of an embodiment of a negative voltage shutdown circuit after an IGBT fault in an IGBT fault detection circuit of the present invention. Figure 4 As shown, the first output end of the MCU is input to the first input end of the driving power conversion module after passing through the switch K1; the second output end of the MCU is input to the second input end of the driving power conversion module after passing through the switch K2; the third output end of the MCU is input to the third input end of the driving power conversion module after passing through the switch K3; the fourth output end of the MCU is input to the fourth input end of the driving module; the first output end of the driving power conversion module is input to the first input end of the driving module, i.e., the VCC(t1) end; the second output end of the driving power conversion module is input to the second input end of the driving module, i.e., the VCC(t2) end; and the third output end of the driving power conversion module is input to the third input end of the driving module, i.e., the VCC(t3) end.

[0061] like Figure 4 As shown, during normal operation (at time t1), the control switch K1 is turned on, and the normal operating voltage VCC (t1) supplies power to the driver module. When the MCU receives a signal indicating an IGBT fault, it begins negative voltage shutdown. During the negative voltage shutdown process, at time t2, switch K1 is turned off, switch K2 is turned on, and switch K3 is turned off. At this time, the voltage of the power supply VCC is converted to a low voltage VCC (t2) by the driver power conversion module. At time t3, switch K1 is turned off, switch K2 is turned off, and switch K3 is turned off, and the power supply is 0V. At time t4, switch K2 is turned on and switch K4 is turned on. At this time, the VCC voltage is clamped to a lower voltage through the current limiting resistor R1 and the voltage regulator diode D2, and then converted to a negative voltage VCC (t3) by the negative voltage module. The negative voltage VCC (t3) reliably shuts down the IGBT. The driver power conversion module, such as a voltage conversion chip, is used to perform voltage conversion.

[0062] In some embodiments, the IGBT protection device according to the solution of the present invention further includes: a driving resistance module; the driving resistance module is arranged between the driving module and the gate of the IGBT.

[0063] Specifically, Figure 3 FIG. 1 is a schematic structural diagram of an embodiment of an IGBT fault detection circuit of the present invention. Figure 3 As shown, the IGBT fault detection circuit includes: a voltage sampling module, a current sampling module, a temperature sampling module, comparators U1, U2, U4, a main chip MCU, a logic chip U3, switches K1, K2, K3, K4, a current limiting resistor R1, a resistor R2, a sampling resistor Rs, an inductor L1, a diode D1, a voltage regulator diode D2, a capacitor C1, and an IGBT.

[0064] like Figure 3 The IGBT fault detection circuit shown uses a BOOST circuit as an example. The input voltage Vin is boosted by inductor L1 and diode D1 to obtain a voltage VP. The voltage is sampled through a resistor divider or other voltage detection circuit (i.e., a voltage sampling module). The boost circuit uses the IGBT switch and inductor L1 to store energy and the reverse electromotive force of diode D1 to boost the voltage. The sampled voltage is compared with the set voltage by comparator U1. If the sampled voltage is higher than the set voltage, a high-level signal is output to the logic judgment module, such as the first input terminal of the logic chip U3. Current sampling is performed through the sampling resistor Rs. The current sampling module detects the voltage difference between the front and rear ends of the sampling resistor Rs. The sampling signal is amplified by the operational amplifier circuit. The sampled current is compared with the set current by comparator U2. If the sampled current is higher than the set current, a high-level signal is output to the logic judgment module, such as the second input terminal of the logic chip U3. Temperature sampling is performed using a temperature sampling module, such as a thermistor. The sampled temperature is compared with the set temperature via a comparator U4. If the sampled temperature is higher than the set temperature, a high-level signal is output to a logic determination module, such as the third input terminal of the logic chip U3. The logic determination module determines whether the IGBT is faulty based on the input level signal. Upon receiving the IGBT fault signal from the logic determination module, the driver module (such as a driver chip or a driver unit centered around the driver chip) stops sending PWM signals, causing the IGBT to hard-off. Upon receiving the IGBT fault signal from the logic determination module, the main control module stops sending PWM switching signals to the driver module and simultaneously sends a shutdown signal to the driver power conversion module, controlling the IGBT to perform negative voltage shutdown.

[0065] The negative voltage module is similar to having multiple power sources, each controlled by a selector switch. During normal operation, the first power source is controlled to be on, such as by controlling switch K1 to be on, and the normal operating voltage VCC is used for power supply, that is, VCC(t1). When the MCU receives a signal indicating an IGBT fault, it initiates negative voltage shutdown in the following sequence: first, power is supplied by the second power source, such as by controlling switch K1 to be off, and controlling switches K2 and K3 to be on, and the power is supplied by VCC(t2), which is lower than VCC(t1). Then, power is supplied by the third power source, such as by controlling switches K1, K2, and K3 to be off, and the power is supplied by 0V. Then, power is supplied by the fourth power source, controlling switch K1 to be off, switch K2 to be on, and switch K4 to be on, that is, the negative voltage VCC(t3) provided by the negative voltage module is used, and the power is supplied by VCC(t3). When turning off the IGBT, if the current amplitude in the IGBT is large, the self-induced electromotive force Ldi / dt generated is too high, and a very high peak voltage will be generated at both ends of the IGBT's collector (C) and emitter (E). At the same time, there will be a burr spike in the IGBT's gate (G) voltage, which will cause the IGBT to be mis-turned on. Step-by-step shutdown will not cause mis-turning on. Among them, the negative pressure module can be seen in Figure 4 and Figure 6 Related instructions.

[0066] like Figure 5 The IGBT fault detection circuit shown uses a BOOST circuit as an example. The input voltage Vin is boosted by inductor L1 and diode D1 to obtain a voltage VP. This voltage is then divided by resistors R4 and R5, or by another voltage detection circuit (i.e., a voltage sampling module) for voltage sampling. The sampled voltage is compared with the set voltage via comparator U1. If the sampled voltage is higher than the set voltage, comparator U1 flips its level and outputs a high-level signal to a logic determination module, such as the first input terminal of the AND logic chip U3. Current sampling is performed via sampling resistor Rs. The current sampling module detects the voltage difference across the sampling resistor Rs. The sampled signal is amplified by an op amp circuit. The sampled current is compared with the set current via comparator U2. If the sampled current is higher than the set current, a high-level signal is output to a logic determination module, such as the second input terminal of the AND logic chip U3. If sampling accuracy and reliability are required, a precision current sensor can be used for current sampling. Temperature sampling is performed through a temperature sampling module such as a thermistor, and the sampled temperature is compared with the set temperature through a comparator U4. If the sampled temperature is higher than the set temperature, a high-level signal is output to the logic judgment module, such as input to the third input terminal of the logic chip U3.

[0067] like Figure 5As shown, when the logic chip U3 determines whether the IGBT is faulty, it sends an IGBT fault signal to the main chip MCU and the driver module when the IGBT is faulty. At this time, after receiving the IGBT fault signal sent by the logic judgment module, the driver module stops sending the PWM signal to make the IGBT hard shut down; the main chip MCU stops sending the PWM signal and sends a control signal to perform negative voltage shutdown at the same time. The control sequence is as follows: When the system where the IGBT is located is working normally (at t1), the main chip MCU controls the switch K1 to turn on, and the normal working voltage VCC (t1) supplies power to the driver module. When the main chip MCU receives the IGBT fault signal When a fault signal is received, negative voltage shutdown begins; at time t2, switch K1 is disconnected, switch K2 is turned on, and switch K3 is turned on. At this time, the VCC voltage is clamped to a lower voltage VCC (t2) through the current limiting resistor R1 and the voltage stabilizing diode D2; at time t3, switches K1, K2, and K3 are turned off. At this time, the VCC voltage is 0V, VCC (0); at time t4, switch K1 is disconnected, switch K2 is turned on, and switch K4 is turned on. At this time, the VCC voltage is clamped to a lower voltage through the current limiting resistor R1 and the voltage stabilizing diode D2, and then converted to a negative voltage VCC (t4) through the negative voltage module, reliably shutting down the IGBT. The negative voltage module can be a power supply module that outputs negative voltage itself, or it can be a negative voltage power supply output through a different reference ground. The negative voltage can reliably shut down the IGBT.

[0068] Figure 6 Schematic diagram of the IGBT turn-off voltage variation over time in the IGBT fault detection circuit of the present invention. After the IGBT fault is determined, when the IGBT is turned off by negative voltage, the turn-off voltage variation over time is as follows: Figure 6 shown.

[0069] Figure 7 FIG. 1 is a schematic diagram showing the structure of another embodiment of the IGBT fault detection circuit of the present invention. Figure 7 As shown, the power supply for comparators U1, U2, and U4, as well as the logic chip U3, can be powered by a separate power supply independent of power supply VCC, such as power supply VCC2. Furthermore, the solution of the present invention is not limited to the BOOST topology; other topologies are also applicable. The solution of the present invention is also not limited to air conditioners; it is also applicable to other power circuits using switching transistors.

[0070] The technical solution of the present invention is adopted, by setting a driving power conversion module between the main control chip and the driving module of the IGBT, and setting a normal power supply module and a negative pressure shutdown module in the driving power conversion module; when the IGBT is working, the voltage across the collector (C) and the emitter (E) of the IGBT, the current Ic between the collector (C) and the emitter (E) of the IGBT, and the temperature of the IGBT are detected; according to the detected voltage across the collector (C) and the emitter (E) of the IGBT, the current Ic between the collector (C) and the emitter (E) of the IGBT, and the temperature of the IGBT, the logic judgment module is used to judge whether the IGB is in operation or not. Whether T is faulty; when the logic judgment module outputs a signal of IGBT fault, the driving module stops sending PWM signals to the IGBT to make the IGBT hard-turn off, the main control chip stops sending PWM switching signals to the driving module and sends a control signal to the driving power conversion module at the same time, so that the driving power conversion module uses negative pressure to turn off the IGBT through the driving module, and performs double shut-off on the IGBT in the event of an IGBT fault. Therefore, by combining the voltage, current and temperature of the IGBT to determine whether the IGBT is faulty, and performing negative pressure shutdown when the IGBT fails, the IGBT can be reliably shut down to avoid mis-turning on the IGBT, which is beneficial to improving the reliability and safety of IGBT protection.

[0071] According to an embodiment of the present invention, an air conditioner corresponding to the IGBT protection device is also provided. The air conditioner may include: the IGBT protection device described above.

[0072] Since the processing and functions implemented by the air conditioner of this embodiment basically correspond to the embodiments, principles and examples of the device, for any details not fully described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0073] The technical solution of the present invention is adopted. For the IGBT, a driving power conversion module is set between the main control chip and the driving module of the IGBT, and a normal power supply module and a negative pressure shutdown module are set in the driving power conversion module. When the IGBT is working, the voltage across the collector (C) and the emitter (E) of the IGBT, the current Ic between the collector (C) and the emitter (E) of the IGBT, and the temperature of the IGBT are detected. According to the detected voltage across the collector (C) and the emitter (E) of the IGBT, the current Ic between the collector (C) and the emitter (E) of the IGBT, and the temperature of the IGBT, a logic judgment module is used to judge whether the IGBT is faulty. When the logic judgment module outputs a signal indicating an IGBT fault, the driving module stops sending a PWM signal to the IGBT to hard-turn off the IGBT, the main control chip stops sending a PWM switching signal to the driving module and simultaneously sends a control signal to the driving power conversion module, so that the driving power conversion module uses negative pressure to turn off the IGBT through the driving module, and performs double shut-off on the IGBT in the event of an IGBT fault, thereby avoiding mis-turning on of the IGBT when the IGBT is turned off.

[0074] According to an embodiment of the present invention, an IGBT protection method for an air conditioner is also provided. Figure 8 FIG2 is a flow chart of an embodiment of the method of the present invention. The IGBT protection method for an air conditioner may include steps S110 to S140.

[0075] In step S110, the voltage across the collector and emitter of the IGBT is obtained, which is recorded as the detection voltage of the IGBT; the current between the collector and emitter of the IGBT is obtained, which is recorded as the detection current of the IGBT; and the temperature of the IGBT is obtained, which is recorded as the detection temperature of the IGBT.

[0076] At step S120 , when the detection voltage of the IGBT is greater than the set voltage, the detection current of the IGBT is greater than the set current, and the detection temperature of the IGBT is greater than the set temperature, a set level signal, such as a high level signal, is output.

[0077] At step S130, when the set level signal is received, the sending of the PWM switching signal to the driving module is stopped, and a control signal is sent to the driving power conversion module at the same time; the control signal is a signal for controlling the driving power conversion module to cause the IGBT to be negatively shut down; wherein, when the sending of the PWM switching signal to the driving module is stopped, the driving module stops outputting the PWM signal to the IGBT, causing the IGBT to be hard-turned off.

[0078] At step S140, the driving power conversion module is enabled to provide a negative voltage to the driving module when receiving the control signal; wherein, when receiving the negative voltage provided by the driving power conversion module, the driving module is enabled to output a negative shutdown signal to the IGBT, so that the IGBT is negatively shut down.

[0079] The solution of the present invention determines whether the IGBT is faulty by detecting the voltage across the collector (C) and emitter (E) of the IGBT, the current Ic between the collector (C) and emitter (E) of the IGBT, and the temperature of the IGBT. When it is determined that the IGBT is faulty, the negative pressure is reliably shut down by driving the power conversion module to prevent the IGBT from being mis-turned on due to the spike voltage, thereby avoiding the IGBT from being mis-turned on when shutting down the IGBT.

[0080] In some embodiments, when the driving power conversion module includes a first switch module, a second switch module, a third switch module, a fourth switch module, a current limiting resistor module, a negative pressure module, and a power conversion module: if the control signal is not received, the first switch module is controlled to be turned on, and the second, third, and fourth switch modules are controlled to be turned off. The time when the control signal is not received is time t1.

[0081] In the case where the driving power conversion module includes a first switch module, a second switch module, a third switch module, a fourth switch module, a current limiting resistor module, a negative voltage module and a power conversion module: if the control signal is received, the driving module is controlled to provide a negative voltage to output a negative shutdown signal to the IGBT, so that the IGBT is negatively shut down.

[0082] The following combination Figure 9 The method of the present invention is shown as a flow chart of an embodiment of controlling the driving module to provide a negative voltage to output a negative shutdown signal to the IGBT, so that the IGBT is shut down at a negative voltage. The flow chart further illustrates the specific process of controlling the driving module to provide a negative voltage to output a negative shutdown signal to the IGBT, so that the IGBT is shut down at a negative voltage, including: steps S210 to S230.

[0083] Step S210: At a first set time, the first switch module is controlled to be turned off, the second switch module and the third switch module are controlled to be turned on, and the fourth switch module is controlled to continue to be turned off, so as to provide a second voltage signal to the driving module. The first set time is, for example, time t2.

[0084] Step S220: At a second set time, the first switch module, the second switch module, and the third switch module are all controlled to be disconnected, and the fourth switch module is controlled to continue to be disconnected, providing a zero voltage signal to the driver module to stop sending a PWM switching signal to the driver module. The second set time is, for example, time t3.

[0085] Step S230: At a third set time, the second switch module and the fourth switch module are both turned on, and the first switch module and the third switch module are further turned off, providing a negative voltage to the driver module so that the driver module outputs a negative shutdown signal to the IGBT, causing the IGBT to shut down under negative voltage. The third set time is, for example, time t4.

[0086] Specifically, during normal operation (at time t1), the control switch K1 is turned on, and the normal operating voltage VCC (t1) supplies power to the driver module. When the MCU receives a signal of an IGBT fault, it starts to perform negative voltage shutdown. During the negative voltage shutdown process, at time t2, the switch K1 is turned off, the switch K2 is turned on, and the switch K3 is turned off. At this time, the voltage of the power supply VCC is converted to a low voltage VCC (t2) by the driver power conversion module. At time t3, the switch K1 is turned off, the switch K2 is turned off, and the switch K3 is turned off, and the power is supplied by a 0V voltage. At time t4, the switch K2 is turned on and the switch K4 is turned on. At this time, the VCC voltage is clamped to a lower voltage through the current limiting resistor R1 and the voltage regulator diode D2, and then converted to a negative voltage VCC (t3) through the negative voltage module. The IGBT is reliably shut down by the negative voltage VCC (t3).

[0087] Since the processing and functions implemented by the method of this embodiment basically correspond to the embodiments, principles and examples of the aforementioned air conditioner, for any details not fully described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0088] According to the technical solution of this embodiment, a driving power conversion module is provided between the main control chip and the driving module of the IGBT, and a normal power supply module and a negative voltage shutdown module are provided in the driving power conversion module. When the IGBT is working, the voltage across the collector (C) and the emitter (E) of the IGBT, the current Ic between the collector (C) and the emitter (E) of the IGBT, and the temperature of the IGBT are detected. Based on the detected voltage across the collector (C) and the emitter (E), the current Ic between the collector (C) and the emitter (E), and the temperature of the IGBT, a logic judgment module is used to determine whether the IGBT is faulty. When the logic judgment module outputs a signal indicating an IGBT fault, the driving module stops sending a PWM signal to the IGBT to hard-turn off the IGBT, and the main control chip stops sending a PWM switching signal to the driving module while sending a control signal to the driving power conversion module, so that the driving power conversion module uses a negative voltage to turn off the IGBT through the driving module. In the event of an IGBT fault, the IGBT is double-shutdown to prevent the IGBT from being mis-turned on due to a spike voltage.

[0089] In summary, it is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0090] The foregoing description is merely an embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of the claims.

Claims

1. An IGBT protection device, characterized in that: include: Voltage sampling module, current sampling module, temperature sampling module, logic judgment module, drive power conversion module, drive module and main control module; among them, The voltage sampling module is provided at the collector of the IGBT and is used to detect the voltage across the collector and emitter of the IGBT, which is recorded as the detection voltage of the IGBT; The current sampling module is provided at the emitter of the IGBT and is used to detect the current between the collector and emitter of the IGBT, which is recorded as the detection current of the IGBT; The temperature sampling module is provided in the heat dissipation area of ​​the IGBT and is used to detect the temperature of the IGBT, which is recorded as the detected temperature of the IGBT; The input end of the logic determination module is connected to the voltage sampling module, the current sampling module and the temperature sampling module respectively; the output end of the logic determination module is connected to the main control module and the driving module respectively; the logic determination module is used to output a set level signal when the detection voltage of the IGBT is greater than the set voltage, the detection current of the IGBT is greater than the set current, and the detection temperature of the IGBT is greater than the set temperature; The main control module is connected to the driving power conversion module and the driving module respectively, and is used to stop sending the PWM switching signal to the driving module when receiving the set level signal output by the logic judgment module, and at the same time send a control signal to the driving power conversion module; the control signal is a signal for controlling the driving power conversion module to turn off the IGBT under negative voltage; The driving power conversion module is connected to the driving module and is used to provide a negative voltage to the driving module when receiving a control signal sent by the main control module; The driving module is connected to the gate of the IGBT and is used to stop outputting the PWM signal to the IGBT when the main control module stops sending the PWM switching signal to the driving module, so as to hard-turn off the IGBT; and, when receiving the negative voltage provided by the driving power conversion module, output a negative shutdown signal to the IGBT, so as to cause the IGBT to be negatively shut down.

2. The IGBT protection device according to claim 1, characterized in that: Also includes: Inductor module, diode module and capacitor module; The voltage sampling module includes: a first voltage dividing resistor module and a second voltage dividing resistor module; wherein, The input voltage is connected to the collector of the IGBT and the anode of the diode module after passing through the inductor module; the cathode of the diode module is grounded after passing through the capacitor module; the cathode of the diode module is also grounded after passing through the first voltage-dividing resistor module and the second voltage-dividing resistor module; the common end of the first voltage-dividing resistor module and the second voltage-dividing resistor module serves as the output end of the voltage sampling module, which is used to output the detection voltage of the IGBT.

3. The IGBT protection device according to claim 1, wherein: The current sampling module includes: a sampling resistor module; the temperature sampling module includes: a thermistor module; wherein, The sampling resistor module is arranged between the emitter of the IGBT and the ground; one end of the sampling resistor module away from the emitter of the IGBT is used to output the detection current of the IGBT.

4. The IGBT protection device according to claim 1, characterized in that: The logic judgment module includes: a first comparison module, a second comparison module, a third comparison module, and an AND logic module; wherein, The first input terminal of the first comparison module is used to input the detection voltage of the IGBT; the second input terminal of the first comparison module is used to input a set voltage; when the detection voltage of the IGBT is greater than the set voltage, the first comparison module outputs a first level signal to the first input terminal of the AND logic module; The first input terminal of the second comparison module is used to input the detection current of the IGBT; the second input terminal of the second comparison module is used to input the set current; when the detection current of the IGBT is greater than the set current, the second comparison module outputs a first level signal to the second input terminal of the AND logic module; The first input terminal of the third comparison module is used to input the detected temperature of the IGBT; the second input terminal of the third comparison module is used to input a set temperature; when the detected temperature of the IGBT is greater than the set temperature, the third comparison module outputs a first level signal to the third input terminal of the AND logic module; The output end of the AND logic module is used to output the set level signal as a signal of the IGBT fault when the first input end of the AND logic module receives the first level signal, the second input end of the AND logic module receives the first level signal, and the third input end of the AND logic module receives the first level signal.

5. The IGBT protection device according to claim 1, characterized in that: The driving power conversion module includes: a first switch module, a second switch module, a third switch module, a fourth switch module, a current limiting resistor module, a negative pressure module and a power conversion module; wherein, The negative electrode of the DC power supply is grounded; the positive electrode of the DC power supply is connected to the first input terminal of the driving module after passing through the first switch module and the power conversion module, and is used to provide a first voltage signal to the driving module when the first switch module is turned on; The positive electrode of the DC power supply is further connected to the second input terminal of the driving module after passing through the second switch module, the current limiting resistor module, the third switch module, and the power conversion module, and is used to provide a second voltage signal to the driving module when the first switch module is disconnected and the second switch module and the third switch module are both connected; and to provide a zero voltage signal to the driving module to stop sending the PWM switching signal to the driving module when the first switch module, the second switch module, and the third switch module are all disconnected; the voltage of the second voltage signal is lower than the voltage of the first voltage signal; The positive electrode of the DC power supply is connected to the third input terminal of the driving module after passing through the second switch module and the current limiting resistor module, and also passing through the fourth switch module, the negative pressure module and the power conversion module. The positive electrode of the DC power supply is used to provide a negative voltage to the driving module when the first switch module and the third switch module are disconnected and the second switch module and the fourth switch module are connected, so that the driving module outputs a negative shutdown signal to the IGBT, causing the IGBT to be negatively shut down.

6. The IGBT protection device according to claim 5, characterized in that: The driving power conversion module further includes: a voltage stabilizing diode module; wherein, The second switch module is connected to the cathode of the voltage-stabilizing diode module after passing through the current-limiting resistor module; the anode of the voltage-stabilizing diode module is grounded; the cathode of the voltage-stabilizing diode module is connected to the second input end of the driving module after passing through the third switch module and the power conversion module; the cathode of the voltage-stabilizing diode module is also connected to the third input end of the driving module after passing through the fourth switch module and the negative pressure module.

7. The IGBT protection device according to any one of claims 1 to 6, characterized in that: Also includes: Driving resistor module; The driving resistance module is arranged between the driving module and the gate of the IGBT.

8. An air conditioner, characterized in that: include: The IGBT protection device according to any one of claims 1 to 7.

9. An IGBT protection method for an air conditioner according to claim 8, characterized in that: include: Obtaining the voltage across the collector and emitter of the IGBT, which is recorded as the detection voltage of the IGBT; Obtaining a current between the collector and emitter of the IGBT, which is recorded as a detection current of the IGBT; and obtaining a temperature of the IGBT, which is recorded as a detection temperature of the IGBT; outputting a set level signal when the detection voltage of the IGBT is greater than a set voltage, the detection current of the IGBT is greater than a set current, and the detection temperature of the IGBT is greater than a set temperature; When the set level signal is received, the PWM switching signal is stopped from being sent to the driving module, and a control signal is sent to the driving power conversion module at the same time; the control signal is a signal for controlling the driving power conversion module to cause the IGBT to be negatively shut down; wherein, when the PWM switching signal is stopped from being sent to the driving module, the driving module stops outputting the PWM signal to the IGBT, causing the IGBT to be hard shut down; The driving power conversion module is enabled to provide a negative voltage to the driving module when receiving the control signal; wherein, when receiving the negative voltage provided by the driving power conversion module, the driving module is enabled to output a negative shutdown signal to the IGBT, so that the IGBT is negatively shut down.

10. The IGBT protection method for an air conditioner according to claim 9, characterized in that: in, In the case where the driving power conversion module includes a first switch module, a second switch module, a third switch module, a fourth switch module, a current limiting resistor module, a negative pressure module and a power conversion module: If the control signal is not received, controlling the first switch module to be turned on, and controlling the second switch module, the third switch module and the fourth switch module to be turned off; If the control signal is received, the driving module is controlled to provide a negative voltage to output a negative shutdown signal to the IGBT, so that the IGBT is turned off by negative voltage, specifically including: At a first set time, the first switch module is controlled to be disconnected, the second switch module and the third switch module are controlled to be connected, and the fourth switch module is controlled to continue to be disconnected, so as to provide a second voltage signal to the driving module; At a second set time, the first switch module, the second switch module, and the third switch module are all controlled to be disconnected, and the fourth switch module is controlled to continue to be disconnected, providing a 0 voltage signal to the driving module to stop sending a PWM switching signal to the driving module; At a third set moment, the second switch module and the fourth switch module are controlled to be turned on, and the first switch module and the third switch module are controlled to continue to be turned off, providing a negative voltage for the driving module, so that the driving module outputs a negative shutdown signal to the IGBT, causing the IGBT to be turned off by negative voltage.

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