A protection device, method and power electronic apparatus for a SiC module

Abstract

The application discloses a protection device and method of a SiC module and a power electronic equipment, and the device comprises: a driving chip, which obtains a control signal based on a PWM signal and a first logic processing signal; a first detection unit, which obtains a first detection result by detecting a drain-source voltage of a MOS tube based on a third logic processing signal; a second detection unit, which obtains a second detection result by detecting a voltage of an internal packaging parasitic inductance; a logic processing unit, which processes the first detection result, the second detection result and the control signal to obtain the first logic processing signal, the second logic processing signal and the third logic processing signal, so as to control the SiC module to be turned off according to the second logic processing signal; and the driving chip stops sending the PWM signal according to the first logic processing signal. According to the scheme, the drain-source voltage of the MOS tube of the SiC module and the voltage of the internal packaging parasitic inductance are combined to judge the short circuit of the SiC module and to timely turn off the SiC module, so that the safety is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of power electronic devices, and particularly relates to a SiC module protection device and method and a power electronic device, in particular to a SiC MOSFET module short-circuit protection detection circuit and method and a power electronic device with the detection circuit. BACKGROUND

[0002] In recent years, with the development of new energy vehicles, industrial frequency conversion, rail transit and aerospace fields, higher requirements for power and performance of power electronic devices are put forward. Power semiconductor modules are a large category, which can be divided into silicon, silicon carbide, gallium nitride and other material types according to different materials. Silicon controlled rectifier module (i.e. silicon carbide module) is one of the power semiconductor modules. Silicon carbide modules (i.e. SiC modules) have gradually replaced traditional silicon modules due to their excellent performance in high voltage, high frequency and high temperature environments, and have become an indispensable key component in these fields.

[0003] Compared with traditional silicon modules, the working conditions of silicon carbide modules are more severe. Since the silicon carbide module has large power and small chip area, the current capacity of the silicon carbide module when short-circuited is weak. In order to ensure the normal and safe operation of the power device, various protection circuits are usually used to protect the silicon carbide module, and the protection time is strictly controlled to reduce the risk of damage or failure of the silicon carbide module and its associated devices after short-circuit.

[0004] The above content is only used to assist in understanding the technical solutions of the present application, and does not represent the acknowledgement of the above content as prior art. SUMMARY

[0005] The purpose of the present application is to provide a SiC module protection device, method and power electronic device to solve the problem that the current capacity of the SiC module when short-circuited is weak, there is a risk of damage or failure, and the running safety is affected. The effect of judging whether the SiC module is short-circuited by combining the drain-source voltage of the MOS tube of the SiC module and the voltage of the internal packaging parasitic inductance of the SiC module, and turning off the SiC module in time when judging that the SiC module is short-circuited, to suppress the short-circuit current and improve the safety of the SiC module operation.

[0006] The application provides a protection device of a SiC module, the SiC module has a MOS tube and an internal package parasitic inductance; the protection device of the SiC module is arranged between a driving chip of the SiC module and the SiC module; the driving chip is controlled by a master control unit of the driving chip; the protection device of the SiC module comprises a first detection unit, a second detection unit, a logic processing unit and a switching amplification unit; the logic processing unit can output a first logic processing signal, a second logic processing signal and a third logic processing signal; wherein the master control unit is used for sending a PWM signal to the driving chip; the driving chip is used for obtaining a control signal based on the PWM signal and the first logic processing signal output by the logic processing unit; the first detection unit is used for detecting a drain-source voltage of the MOS tube under the action of the third logic processing signal output by the logic processing unit; and determining whether the SiC module is short-circuited according to the drain-source voltage of the MOS tube to obtain a first detection result; the second detection unit is used for detecting a voltage of the internal package parasitic inductance; and determining whether the SiC module is short-circuited according to the voltage of the internal package parasitic inductance to obtain a second detection result; the logic processing unit is used for performing logic processing on the first detection result output by the first detection unit, the second detection result output by the second detection unit and the control signal output by the driving chip to output the first logic processing signal, the second logic processing signal and the third logic processing signal; the switching amplification unit is used for sending an off signal under the condition that the second logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, so as to control the SiC module to be turned off by using the off signal; and the driving chip is further used for feeding back the first logic processing signal output by the logic processing unit to the master control unit under the condition that the first logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, so as to make the master control unit stop sending the PWM signal.

[0007] In some embodiments, the first detection unit comprises: a first diode module, a first sampling resistor module, a first current-limiting resistor module, a comparison module, and a switch tube module; wherein the drain of the MOS tube is connected to the cathode of the first diode module; the anode of the first diode module is sampled by the first sampling resistor module to obtain the drain-source voltage of the MOS tube and then input to the inverting input terminal of the comparison module; a preset voltage threshold is input to the non-inverting input terminal of the comparison module; the output terminal of the comparison module can output the first detection result; the control terminal of the switch tube module is used for receiving the third logic processing signal; the first connection terminal of the switch tube module is connected to the source auxiliary terminal of the MOS tube; and the second connection terminal of the switch tube module is connected to the inverting input terminal of the comparison module through the first current-limiting resistor module.

[0008] In some embodiments, the first detection unit further comprises at least one of: a first voltage stabilizing diode module and a blanking capacitor module; wherein the inverting input terminal of the comparison module is connected to the cathode of the first voltage stabilizing diode module; the anode of the first voltage stabilizing diode module is connected to the source auxiliary terminal of the MOS tube; the inverting input terminal of the comparison module is connected to the source auxiliary terminal of the MOS tube through the blanking capacitor module; wherein, in the case that the control signal output by the drive chip is a low-level signal, the first detection unit is in a non-working state; in the case that the control signal output by the drive chip is a high-level signal, the first detection unit is in a working state; in the case that the drain-source voltage of the MOS tube is less than the preset voltage threshold, the comparison module outputs a high-level signal indicating that the SiC module is not short-circuited as the first detection result; in the case that the drain-source voltage of the MOS tube is greater than the preset voltage threshold, the comparison module outputs a low-level signal indicating that the SiC module is short-circuited as the first detection result.

[0009] In some embodiments, the second detection unit comprises: a second sampling resistor module, a second current-limiting resistor module, an output resistor module, and an optocoupler module; wherein the source auxiliary terminal of the MOS tube is connected to the first connection terminal of the second sampling resistor module; the second connection terminal of the second sampling resistor module can be connected to the anode of the diode side of the optocoupler module; the source main terminal of the MOS tube is connected to the cathode of the diode side of the optocoupler module; a preset DC power supply is connected to the collector of the transistor side of the optocoupler module through the second current-limiting resistor module; the collector of the transistor side of the optocoupler module outputs the second detection result through the output resistor module; and the emitter of the transistor side of the optocoupler module is grounded.

[0010] In some embodiments, the second detection unit further comprises at least one of a second zener diode module, a second diode module, and a reference resistor module; wherein the second connection end of the second sampling resistor module is connected to the cathode of the second zener diode module; the anode of the second zener diode module is connected to the anode of the diode side of the optocoupler module; the second connection end of the second sampling resistor module is connected to the source main terminal of the MOS tube through the reference resistor module; the second connection end of the second sampling resistor module is connected to the cathode of the second diode module; the anode of the second diode module is connected to the source main terminal of the MOS tube; wherein, when the voltage corresponding to the current slope of the internal packaging parasitic inductance is less than the preset voltage threshold, the optocoupler module is not turned on, and the output end of the optocoupler module is a high-level signal indicating that the SiC module is not short-circuited as the second detection result; when the voltage corresponding to the current slope of the internal packaging parasitic inductance is greater than the preset voltage threshold, the optocoupler module is turned on, and the output end of the optocoupler module is a low-level signal indicating that the SiC module is short-circuited as the second detection result.

[0011] In some embodiments, the logic processing unit comprises a first logic module, a second logic module, and a third logic module; wherein the logic processing unit performs logic processing based on the first detection result output by the first detection unit, the second detection result output by the second detection unit, and the control signal output by the driving chip, and outputs a first logic processing signal, a second logic processing signal, and a third logic processing signal, including: the first logic module is configured to perform AND logic processing based on the first detection result and the second detection result to obtain the first logic processing signal output by the logic processing unit; the second logic module is configured to perform AND logic processing based on the first logic processing signal output by the logic processing unit and the control signal to obtain the second logic processing signal output by the logic processing unit; and the third logic module is configured to perform NOT logic processing based on the second logic processing signal output by the logic processing unit to obtain the third logic processing signal output by the logic processing unit.

[0012] In order to match the above-mentioned device, the present application further provides an electric power electronic device comprising the above-mentioned SiC module protection device.

[0013] In some embodiments, the logic processing unit comprises a first logic module, a second logic module, and a third logic module; wherein, through the logic processing unit, the first detection result output by the first detection unit, the second detection result output by the second detection unit, and the control signal output by the driving chip are logically processed to output the first logic processing signal, the second logic processing signal, and the third logic processing signal, which comprises: through the first logic module, the first detection result and the second detection result are logically processed to obtain the first logic processing signal output by the logic processing unit; through the second logic module, the first logic processing signal output by the logic processing unit and the control signal are logically processed to obtain the second logic processing signal output by the logic processing unit; and through the third logic module, the second logic processing signal output by the logic processing unit is logically processed to obtain the third logic processing signal output by the logic processing unit.

[0014] In some embodiments, the logic processing unit comprises a first logic module, a second logic module, and a third logic module; wherein, through the logic processing unit, the first detection result output by the first detection unit, the second detection result output by the second detection unit, and the control signal output by the driving chip are logically processed to output the first logic processing signal, the second logic processing signal, and the third logic processing signal, which comprises: through the first logic module, the first detection result and the second detection result are logically processed to obtain the first logic processing signal output by the logic processing unit; through the second logic module, the first logic processing signal output by the logic processing unit and the control signal are logically processed to obtain the second logic processing signal output by the logic processing unit; and through the third logic module, the second logic processing signal output by the logic processing unit is logically processed to obtain the third logic processing signal output by the logic processing unit.

[0015] Therefore, the scheme of the application, by setting the first detection unit (such as the desaturation detection unit), the second detection unit (such as the current slope detection unit), the logic processing unit (such as the fault summary and shutdown unit), and the switching amplification unit (such as the push-pull amplification unit) between the driving chip of the SiC module and the SiC module, the master control DSP sends the PWM signal to control the driving chip, and the driving chip outputs the control signal to the desaturation detection unit and the push-pull amplification unit based on the PWM signal and the signal output by the fault summary and shutdown unit; the desaturation detection unit is used to detect the drain-source voltage of the MOS tube of the SiC module under the control of the control signal output by the driving chip to determine whether the SiC module has a short circuit to obtain a first detection result, the current slope detection unit is used to detect the voltage of the internal packaging parasitic inductance of the SiC module to determine whether the SiC module has a short circuit to obtain a second detection result, and the fault summary and shutdown unit is used to output the summary signal to the push-pull amplification unit and the driving chip according to the first detection result and the second detection result to shut down the SiC module through the push-pull amplification unit when the SiC module has a short circuit and feedback to the master control DSP through the driving chip to make the master control DSP stop sending the PWM signal; thereby, whether the SiC module has a short circuit is determined by combining the drain-source voltage of the MOS tube of the SiC module and the voltage of the internal packaging parasitic inductance of the SiC module, and the SiC module is shut down in time when it is determined that the SiC module has a short circuit, so as to suppress the short circuit current and improve the safety of the operation of the SiC module.

[0016] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the application.

[0017] The technical scheme of the present application will be further described in detail below with the aid of the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The structural schematic diagram of an embodiment of the protection device of the SiC module of the present application;

[0019] Figure 2 The structural schematic diagram of the driving and short circuit protection circuit of the SiC module;

[0020] Figure 3 The electrical principle schematic diagram of the driving and short circuit protection circuit of the SiC module;

[0021] Figure 4 The electrical principle schematic diagram of the desaturation detection unit in the driving and short circuit protection circuit of the SiC module;

[0022] Figure 5 The electrical principle schematic diagram of the current slope detection unit in the driving and short circuit protection circuit of the SiC module;

[0023] Figure 6 Electrical schematic diagram of a fault summary and shutdown unit in a driving and short circuit protection circuit of a SiC module;

[0024] Figure 7 Flowchart of an embodiment of a protection method for a SiC module of the present application;

[0025] Figure 8 Flowchart of an embodiment of a method of the present application, in which a first detection result output by the first detection unit, a second detection result output by the second detection unit, and a control signal output by the driving chip are logically processed. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the present application clearer, the technical solutions of the present application will be described below in connection with specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0027] It is considered that the SiC module has weak ability to withstand current when short-circuited, and there is a risk of damage or failure, which affects the operation safety. The short circuit of a silicon carbide module (i.e. SiC module) is divided into two categories: one type of short circuit is an internal bridge arm short circuit, also known as "straight through", which is caused by the simultaneous turn-on of two power devices in a bridge arm; one type of short circuit is due to the small inductance in the loop, and the current rises very quickly when short-circuited, i.e. the current slope is large; the second type of short circuit is a bridge arm to bridge arm short circuit, which is generally a bridge arm to bridge arm short circuit or a bridge arm to ground short circuit, and the inductance of this type of short circuit is slightly larger, which is in the order of uH, so the current rise speed when this type of short circuit occurs will be slower than that of the first type of short circuit. In related schemes, the detection method of SiC module (such as SiC MOSFET module) short circuit is divided into several types:

[0028] The first type is to detect the on-state voltage drop V ds to protect, but the detection has a certain blanking time, and the detection of the second type of short circuit is not timely. In the first method, since Vds increases with the increase of current, it is only judged that a short circuit occurs when Vds is greater than a certain threshold value, and the current of the second type of short circuit rises slowly, so the time of detecting the fault by Vds is also slow.

[0029] The second type is to detect the current slope of the parasitic inductance inside the silicon carbide module to determine whether a short circuit occurs, but the specific inductance value cannot be determined, so there may be a protection blind area.

[0030] The third method involves collecting the voltage drop V of the silicon carbide module. ds and conduction current I C One method achieves protection by calculating instantaneous power and heat loss, but this requires computation, resulting in complex circuitry and significant time delays. The third method requires hardware integration calculations, further complicating the circuitry and increasing the processing time.

[0031] Therefore, the present invention proposes a protection device for SiC modules, specifically a detection circuit for short-circuit protection of SiC MOSFET modules. By detecting the changes in different positions of the SiC module when a short circuit occurs, the SiC module is quickly turned off based on the detection results to suppress the short-circuit current and improve the safety of SiC module operation.

[0032] According to an embodiment of the present invention, a protection device for a SiC module is provided. See also... Figure 1 The diagram shows a structural schematic of an embodiment of the device of the present invention. The SiC module includes a MOSFET and an internally packaged parasitic inductor (e.g., inductor Ls). The source auxiliary terminal of the MOSFET is connected to a first connection terminal of the internally packaged parasitic inductor, and the source main terminal of the MOSFET is connected to a second connection terminal of the internally packaged parasitic inductor. A protection device for the SiC module is disposed between the driver chip and the SiC module. The driver chip is controlled by a main control unit, such as a main control DSP. More specifically, the SiC module also includes a diode. The SiC module internally includes a MOSFET and a diode (collectively referred to as SiC power device T1), and a parasitic inductor Ls between the source auxiliary terminal and the source main terminal of the MOSFET. s . Figure 2 This is a schematic diagram of the driving and short-circuit protection circuit of the SiC module. Figure 3 This is a schematic diagram of the electrical principle of the SiC module's drive and short-circuit protection circuit. Figure 2 and Figure 3 In the example shown, T1 is a SiC power device, g is the gate of the MOSFET, d is the drain of the MOSFET, s' is the source auxiliary terminal of the MOSFET, and s is the source main terminal of the MOSFET; L s Parasitic inductors are packaged internally within the SiC module. In the solution of this invention, as... Figure 1 As shown, the protection device for the SiC module includes: a first detection unit (such as...) Figure 2 The desaturation detection unit shown), the second detection unit (as shown) Figure 2 The current slope detection unit shown), logic processing unit (such as...) Figure 2 The fault summary and shutdown unit shown), and the switching amplification unit (such as...) Figure 2The push-pull amplification unit is shown in the figure) The logic processing unit can output a first logic processing signal, a second logic processing signal and a third logic processing signal.

[0033] The master control unit is configured to send a PWM signal to the drive chip.

[0034] The drive chip is configured to obtain a control signal based on the PWM signal and the first logic processing signal output by the logic processing unit, and output the second logic processing signal and the third logic processing signal through the logic processing unit based on the control signal, output the second logic processing signal output by the logic processing unit to the switching amplification unit, and output the third logic processing signal output by the logic processing unit to the first detection unit.

[0035] The first detection unit is configured to detect the drain-source voltage of the MOS tube under the action of the third logic processing signal output by the logic processing unit, and determine whether the SiC module is short-circuited according to the drain-source voltage of the MOS tube to obtain a first detection result.

[0036] The second detection unit is configured to detect the voltage of the internal packaging parasitic inductance, and determine whether the SiC module is short-circuited according to the voltage of the internal packaging parasitic inductance to obtain a second detection result, and the logic processing unit can combine the first detection result, the second detection result and the control signal output by the drive chip to perform logic processing and output the first logic processing signal, the second logic processing signal and the third logic processing signal.

[0037] The logic processing unit is configured to combine the first detection result output by the first detection unit, the second detection result output by the second detection unit and the control signal output by the drive chip to perform logic processing and output the first logic processing signal, the second logic processing signal and the third logic processing signal, output the first logic processing signal to the drive chip, output the second logic processing signal output by the logic processing unit to the switching amplification unit, and output the third logic processing signal output by the logic processing unit to the first detection unit.

[0038] The switching amplification unit is configured to send an off signal when the second logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, so as to control the SiC module to be turned off by using the off signal.

[0039] The driver chip is also configured to, when the first logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, feed back the first logic processing signal output by the logic processing unit to the main control unit so that the main control unit stops sending the PWM signal.

[0040] The present invention proposes a detection scheme for short-circuit protection of SiC MOSFET modules, as follows: Figure 2 As shown, the SiC module's drive and short-circuit protection circuit mainly consists of a main control DSP, SiC power devices (i.e., the SiC module), and a drive and short-circuit protection circuit. The drive and short-circuit protection circuit includes a driver chip, a push-pull amplifier unit, a desaturation detection unit, a current slope detection unit, and a fault summary and shutdown unit. The principle of the SiC module's drive and short-circuit protection circuit is as follows: Figure 3 As shown, in order to enable those skilled in the art to more clearly understand the embodiments of the present invention, the following description is provided in conjunction with... Figure 4 , Figure 5 and Figure 6 The example shown clearly and completely describes the SiC module's drive and short-circuit protection circuit by breaking it down into three parts. Figure 4 This is a schematic diagram of the desaturation detection unit in the drive and short-circuit protection circuit of the SiC module.

[0041] like Figure 2As shown, in the driving and short-circuit protection circuit of the SiC module (i.e. SiC power device T1 such as MOS tube), the main control DSP sends a PWM control signal to the driving chip in the driving and short-circuit protection circuit, and after logical conversion by the driving chip, the signal is combined with the signal of the fault aggregation and shutdown unit to obtain an output signal and output to the desaturation detection unit and the push-pull amplification unit, respectively. The output signal is used to control whether the desaturation detection unit works. The push-pull amplification unit controls the opening and closing of the SiC power device according to the output signal. The desaturation detection unit judges whether the SiC power device has a short circuit by detecting the voltage between the drain (such as the drain d of the MOS tube) and the source (such as the source s' of the MOS tube) of the MOS tube of the SiC power device to obtain a detection result, and outputs the detection result to the fault aggregation and shutdown unit. The current slope detection unit judges whether the device has a short circuit by detecting the voltage of the parasitic inductance (such as inductance Ls) inside the SiC module package, and outputs the detection result to the fault aggregation and shutdown unit. The fault aggregation and shutdown unit aggregates the above two signals, and outputs them to the push-pull amplification unit after being combined with the output signal of the driving chip, or feeds back to the driving chip and then to the main control DSP, so that the main control DSP stops sending the PWM control signal. This control mode and structure can improve the stability of the short-circuit protection trigger of the SiC module to a certain extent, reduce the protection blind area, and reduce the time from the occurrence of the SiC module short circuit to the shutdown of the SiC module.

[0042] In the scheme of the present application, by detecting the changes at different positions of the SiC module when a short circuit occurs, and according to the detection result, the SiC module is quickly shut down, thereby realizing the suppression of the short-circuit current, effectively reducing the temperature of the SiC module and the downstream equipment, and improving the safety and stability of the operation of the SiC module. At the same time, the problem of the protection circuit of the SiC module in the related scheme not detecting in time when a short circuit occurs is solved, the problem of the protection circuit of the SiC module in the related scheme having a protection blind area when detecting is solved, and the problem of the protection circuit of the SiC module in the related scheme being complex and having a large delay is solved.

[0043] In some embodiments, the first detection unit includes a first diode module (such as a high-voltage fast-recovery diode D1), a first sampling resistance module (such as a resistance R1), a first current-limiting resistance module (such as a resistance R2), a comparison module (such as an operational amplifier U2), and a switching tube module (such as an NPN triode M1). The resistance R1 can control the blanking time when a short circuit occurs by changing the resistance value. The resistance R2 is a current-limiting resistance to prevent damage to the NPN triode M1 when it is working.

[0044] The anode of the first diode module is connected with the source auxiliary terminal of the MOS tube through the first sampling resistor module, and the anode of the first diode module is input to the non-inverting input end of the comparison module after the drain-source voltage of the MOS tube is sampled. A preset voltage threshold (such as a voltage threshold V Ref for fault judgment set in advance) is input to the non-inverting input end of the comparison module. The output end of the comparison module can output the first detection result. The control end (such as the base of the NPN triode M1) of the switch tube module is used for receiving the third logic processing signal (such as a control signal V M1 ). The first connection end (such as the emitter of the NPN triode M1) of the switch tube module is connected with the source auxiliary terminal of the MOS tube. The second connection end (such as the collector of the NPN triode M1) of the switch tube module is connected with the non-inverting input end of the comparison module through the first current limiting resistor module.

[0045] In the scheme of the application, whether the conduction voltage drop V ds between the drain and the source of the MOS tube exceeds the preset voltage threshold is judged by using the first detection unit, which is beneficial to improve the detection speed of the SiC module short circuit detection and reduce the protection blind area.

[0046] In some embodiments, the first detection unit further comprises at least one of the following: a first zener diode module (such as a zener diode D2) and a blanking capacitor module (such as a blanking capacitor C4).

[0047] The non-inverting input end of the comparison module is connected with the cathode of the first zener diode module. The anode of the first zener diode module is connected with the source auxiliary terminal of the MOS tube. The non-inverting input end of the comparison module is connected with the source auxiliary terminal of the MOS tube through the blanking capacitor module. In the case that the control signal output by the drive chip is a low-level signal, the first detection unit is in a non-working state. In the case that the control signal output by the drive chip is a high-level signal, the first detection unit is in a working state. In the case that the drain-source voltage of the MOS tube is less than the preset voltage threshold, the comparison module outputs a high-level signal indicating that the SiC module is not short-circuited as the first detection result. In the case that the drain-source voltage of the MOS tube is greater than the preset voltage threshold, the comparison module outputs a low-level signal indicating that the SiC module is short-circuited as the first detection result.

[0048] On the basis of Figure 3 , the principle of the desaturation detection unit in the driving and short circuit protection circuit of the SiC module is as shown in Figure 4 . As Figure 4As shown, the desaturation detection unit comprises: a high-voltage fast recovery diode D1, a voltage stabilizing diode D2, an NPN triode M1, a high-precision current source I A , a resistor R1 and a resistor R2, a blanking capacitor C4 and an operational amplifier U2. Among them, the control signal V M1 is input to the base of the NPN triode M1, the emitter of the NPN triode M1 is connected to the source auxiliary terminal s' of the MOS tube, and the collector of the NPN triode M1 is connected to the source auxiliary terminal s' of the MOS tube through the resistor R2 and the blanking capacitor C4. The power supply VCC is connected to the cathode of the voltage stabilizing diode D2 through the high-precision current source I A ; the anode of the voltage stabilizing diode D2 is connected to the source auxiliary terminal s' of the MOS tube; the cathode of the high-voltage fast recovery diode D1 is connected to the drain d of the MOS tube; the anode of the high-voltage fast recovery diode D1 is connected to the inverting input terminal of the operational amplifier U2 through the resistor R1; and the inverting input terminal of the operational amplifier U2 is also connected to the cathode of the voltage stabilizing diode D2 and the common terminal of the resistor R2 and the blanking capacitor C4. The voltage threshold V Ref is input to the non-inverting input terminal of the operational amplifier U2; and the output terminal of the operational amplifier U2 outputs the first detection result V Fault1 .

[0049] When the control signal V M1 at the base of the NPN triode M1 is at a high level, the NPN triode M1 is turned on, and the desaturation detection unit is in a non-working state, at which time the voltage of the blanking capacitor C4 is a fixed voltage: Since the voltage of the blanking capacitor C4 is less than the voltage threshold V Ref set in advance for fault judgment, the output terminal of the operational amplifier U2 outputs a signal at a high level, i.e., the first detection result V Fault1 is a signal at a high level.

[0050] When the control signal V M1 at the base of the NPN triode M1 is at a low level, the NPN triode M1 is turned off, and the desaturation detection unit is in a working state, at which time the voltage of the blanking capacitor C4 is:

[0051] is the voltage on the resistor R1, and is the voltage on the high-voltage fast recovery diode D1. If the SiC power device is normally turned on, the voltage of the blanking capacitor C4 will also be less than the voltage threshold V Ref set in advance for fault judgment, so that the output terminal of the operational amplifier U2 outputs a signal at a high level, i.e., the first detection result VFault1 A high-level signal; if the SiC power device is short-circuited, the drain-source voltage V of the SiC power device... ds' It will increase as the current increases, according to the formula above. It also increases in size when Greater than V Ref At that time, the output of operational amplifier U2 outputs a low-level signal, i.e., the first detection result V. Fault1 This is a low-level signal. The current source I... A The blanking capacitor C4 and resistor R1 can be selected and matched according to the actual situation. Usually, the blanking time is set within 3us to ensure that the short circuit protection is triggered in time.

[0052] In the solution of the present invention, a first Zener diode module and a blanking capacitor module are provided in the first detection unit, which can better protect the safety of the first detection unit itself, improve the accuracy of the first detection result obtained by the first detection unit, and thus improve the accuracy of the short circuit judgment of the SiC module.

[0053] In some embodiments, the second detection unit includes: a second sampling resistor module (e.g., resistor R3), a second current-limiting resistor module (e.g., resistor R5), an output resistor module (e.g., resistor R6), and an optocoupler module (e.g., optocoupler U3). Resistor R3 divides the voltage across resistor R4. When optocoupler U3 is on, resistor R5 limits the current to prevent damage to optocoupler U3. When optocoupler U3 is off, resistors R5 and R6 divide the voltage, determining the high level of the AND gate U4 to a corresponding value.

[0054] The MOS transistor's source auxiliary terminal is connected to the first connection terminal of the second sampling resistor module; the second connection terminal of the second sampling resistor module can be connected to the anode of the diode side of the optocoupler module; the MOS transistor's source main terminal is connected to the cathode of the diode side of the optocoupler module. A preset DC power supply (e.g., power supply Vcc) is connected to the collector of the transistor side of the optocoupler module after passing through the second current-limiting resistor module; the collector of the transistor side of the optocoupler module outputs the second detection result after passing through the output resistor module; the emitter of the transistor side of the optocoupler module is grounded (e.g., ground GND).

[0055] In the solution of this invention, the second detection unit is used to determine the current slope of the parasitic inductance inside the SiC module. Whether the current slope exceeds the preset threshold is beneficial to improving the detection speed of short circuit detection in SiC modules and reducing the protection blind zone.

[0056] In the scheme of the present application, the detection circuit combining the first detection unit (such as the desaturation detection circuit) and the second detection unit (such as the current slope detection circuit) is adopted, which solves the problem of not timely detection of the two types of short circuit in the related scheme, also reduces the protection blind area, improves the stability and reliability of the SiC module short circuit protection, and ensures that the circuit can be triggered stably when the SiC module is short-circuited.

[0057] In some embodiments, the second detection unit further comprises at least one of the following: a second voltage stabilizing diode module (such as a voltage stabilizing tube D3), a second diode module (such as a diode D4), and a reference resistance module (such as a resistance R4). The resistance R3 and the resistance R4 can perform voltage division, and the diode D4 can perform freewheeling on the light emitting diode of the diode side of the optocoupler U3.

[0058] The second connection end of the second sampling resistance module is connected to the cathode of the second voltage stabilizing diode module; the anode of the second voltage stabilizing diode module is connected to the anode of the diode side of the optocoupler module. The second connection end of the second sampling resistance module is connected to the source main terminal of the MOS tube through the reference resistance module. The second connection end of the second sampling resistance module is connected to the cathode of the second diode module; the anode of the second diode module is connected to the source main terminal of the MOS tube.

[0059] In the case where the voltage corresponding to the current slope of the internal packaging parasitic inductance is less than the preset voltage threshold, the optocoupler module does not conduct, and the output end of the optocoupler module is a high-level signal indicating that the SiC module is not short-circuited as the second detection result; in the case where the voltage corresponding to the current slope of the internal packaging parasitic inductance is greater than the preset voltage threshold, the optocoupler module conducts, and the output end of the optocoupler module is a low-level signal indicating that the SiC module is short-circuited as the second detection result.

[0060] Figure 5 The electrical principle diagram of the current slope detection unit in the driving and short circuit protection circuit of the SiC module is shown in Figure 3 On the basis of Figure 5 , the principle of the fault summary and shutdown unit in the driving and short circuit protection circuit of the SiC module is shown in Figure 5The fault summary and shutdown unit includes a voltage stabilizing tube D3, a diode D4, resistors R3, R4, R5 and R6, and an optical coupler U3. The source auxiliary terminal s' of the MOS tube is connected to the cathode of the voltage stabilizing tube D3 through the resistor R3; the anode of the voltage stabilizing tube D3 is connected to the anode of the diode side of the optical coupler U3; and the cathode of the diode side of the optical coupler U3 is connected to the source main terminal s of the MOS tube. The diode D4 is connected in parallel with the resistor R4, and the cathode of the diode D4 is connected to the cathode of the voltage stabilizing tube D3, and the anode of the diode D4 is connected to the source main terminal s of the MOS tube. The power supply VCC is connected to the collector of the transistor side of the optical coupler U3 through the resistor R5; the emitter of the transistor side of the optical coupler U3 is grounded; and the collector of the transistor side of the optical coupler U3 is connected to the second detection result V Fault2 .

[0061] The current slope detection unit judges whether a short circuit occurs by detecting the voltage of the parasitic inductance L s inside the SiC module s . The voltage V Ls of the parasitic inductance L

[0062] When the SiC power device is normally turned on, the current is normally rising, and the current slope is a small value; but when the SiC power device is short-circuited, the current will rise by several times, and the current slope is also several times of the normal current slope, according to the above formula, the voltage V s of the parasitic inductance L Ls also increases. For example, the voltage V s of the parasitic inductance L Ls is 1V to 2V under normal circumstances, and will surge to 4V to 5V when short-circuited. The threshold of the short-circuit protection trigger can be set by adjusting the voltage stabilizing tube D3, the resistor R3 and the resistor R4. When the voltage V s of the parasitic inductance L Ls reaches a certain value, the optical coupler U3 is turned on, and the signal level of the second detection result V Fault2 changes from high level to low level. Since the size of the current slope is used to determine whether a short circuit occurs, the detection of the second-class short circuit is more timely.

[0063] In the scheme of the application, the second voltage stabilizing diode module and the second diode module, and the reference resistance module are arranged in the second detection unit, so that the safety of the second detection unit itself can be better protected, the accuracy of the second detection result obtained by the second detection unit is improved, and the accuracy of the short-circuit judgment of the SiC module is improved.

[0064] In the scheme of the application, the on-voltage drop V dsand the current slope of the parasitic inductance inside the SiC module package The combined short-circuit detection circuit can improve the detection speed and reliability of short circuit detection, and reduce the protection blind zone.

[0065] In some implementations, the logic processing unit includes: a first logic module (such as a logic AND gate U4), a second logic module (such as a logic AND gate U5), and a third logic module (such as a logic NOT gate U6).

[0066] The logic processing unit combines the first detection result output by the first detection unit, the second detection result output by the second detection unit, and the control signal output by the driver chip to perform logic processing, and outputs a first logic processing signal, a second logic processing signal, and a third logic processing signal, including:

[0067] The first logic module is configured to perform AND logic processing based on the first detection result and the second detection result to obtain a first logic processing signal output by the logic processing unit, and output the first logic processing signal output by the logic processing unit to the driver chip.

[0068] The second logic module is used to perform AND logic processing on the first logic processing signal output by the logic processing unit and the control signal to obtain the second logic processing signal output by the logic processing unit, and output the second logic processing signal output by the logic processing unit to the switching amplifier unit.

[0069] The third logic module is used to perform non-logic processing based on the second logic processing signal output by the logic processing unit to obtain the third logic processing signal output by the logic processing unit, and output the third logic processing signal output by the logic processing unit to the first detection unit.

[0070] Figure 6 This is a schematic diagram of the fault summary and shutdown unit in the drive and short-circuit protection circuit of the SiC module. Figure 3 Based on this, the principle of the fault summary and shutdown unit in the SiC module's drive and short-circuit protection circuit is as follows: Figure 6 As shown. Figure 6 As shown, the fault summary and shutdown unit includes: AND gates U4 and U5, and NOT gate U6. The first input of driver chip U1 receives the PWM signal, and the second input receives the output signal (Fault signal) of the fault summary and shutdown unit. The first output of driver chip U1 is connected to the input of the push-pull amplifier unit, and the second output is connected to the input of the main control DSP. Driver chip U1 can be an IC1ED020I12 chip.

[0071] The first output end of the driving chip U1 is connected to the first input end of the logic AND gate U5, and the first detection result V Fault1 The first input end of the logic AND gate U4 is inputted with the second detection result V Fault2 The second input end of the logic AND gate U4 is inputted with the second detection result V, and the output end of the logic AND gate U4 is connected to the second input end of the driving chip U1. The output end of the logic AND gate U4 is also connected to the second input end of the logic AND gate U5, and the output end of the logic AND gate U5 is connected to the input end of the push-pull amplification unit. The output end of the push-pull amplification unit is connected to the gate g of the MOS tube. The output end of the logic AND gate U5 is also connected to the input end of the logic NOT gate U6, and the output end of the logic NOT gate U6 outputs the control signal V M1 to the base of the NPN triode M1.

[0072] As shown in Figure 6 , the logic AND gate U4 receives the level signals outputted by the desaturation detection unit and the current slope detection unit, such as the first detection result V Fault1 and the second detection result V Fault2 . Only when both of them are high (i.e. no short circuit), the logic AND gate U4 outputs high level. If one or more of them is low (i.e. there is a short circuit), the logic AND gate U4 outputs low level. The output signal of the logic AND gate U4 is sent to the driving chip U1, and then fed back to the main control DSP by the driving chip U1, so that the main control DSP stops sending PWM waves. The output signal of the logic AND gate U4 is also outputted after being ANDed with the control signal outputted by the driving chip U1 through the logic AND gate U5, so that when there is a short circuit, the voltage at the input end of the push-pull amplification unit is quickly pulled down, and the SiC module is quickly disconnected. The output signal of the logic AND gate U5 is also used to control whether the desaturation detection unit works after being outputted through the logic NOT gate U6. Compared with the related scheme in which the fault signal is fed back to the main control DSP, and then the main control DSP stops sending waves (i.e. stops sending PWM signals), the scheme of the present application can reduce the delay of the wave-off and reduce the short circuit time of the SiC module by using the logic circuit to turn off in advance.

[0073] In the scheme of the present application, the fast-off mode composed of the logic circuit is used to reduce the delay of triggering the gate-off after detecting the short circuit. In this way, the fast-off mode composed of the logic circuit is adopted, the circuit is simple, the response speed is fast, and the risk of the SiC module being damaged or disabled due to the long short circuit time can be effectively reduced when the short circuit of the SiC module occurs, and the service life of the SiC module is improved.

[0074] In some embodiments, the switching amplification unit comprises a push-pull power amplifier.

[0075] In the scheme of the present application, the push-pull amplification unit is used as a controllable switch, such as a push-pull power amplifier. The push-pull amplification unit adopts a push-pull structure, such as: the push-pull structure mainly consists of an NPN transistor, a PNP transistor and resistors and capacitors, one transistor is responsible for pulling up the output voltage, and one transistor is responsible for pulling down the output voltage, hence the name "push-pull", the main function is to improve the driving ability and reduce signal distortion.

[0076] It should be noted that in the above embodiment, only the short circuit protection of the MOSFET power device is listed, and the protection circuit can also be used for short circuit protection of other power devices such as MOS tubes. In the above embodiment, only the optocoupler U3 is used as a signal isolation and switching device, but it should be understood that the optocoupler U3 can be replaced by other switching devices with fast response speed and isolation measures (such as transformers). The above embodiment contains specific value parameters for demonstration, but it should be understood that the parameters do not need to be exactly equal to the corresponding values, and should be determined according to the actual situation.

[0077] In the scheme of the present application, the detection circuit is combined with the current source-based drain-source voltage detection and the optocoupler-based inductance current rate of change detection. Compared with the integral-based inductance current rate of change detection and other detection methods in related schemes, the entire detection circuit loop is simpler, the circuit delay is low, and the detection of short circuit is more rapid and reliable. After detecting the short circuit fault, one is directly combined with the output signal of the drive chip U1 and then output to the push-pull amplification unit, and the other is fed back to the drive chip U1 and then fed back to the main control DSP by the drive chip U1, so that the main control DSP stops sending PWM waves. A fast shutdown method composed of a logic circuit is used, which can directly shut down the control signal of the power device when a short circuit is detected, reducing the delay from detection to triggering the gate to shut down.

[0078] The technical scheme of the present application is characterized in that a desaturation detection unit, a current slope detection unit, a fault summary and shutdown unit, and a push-pull amplification unit are arranged between the drive chip of the SiC module and the SiC module, the main control DSP sends a PWM signal to control the drive chip, the drive chip outputs a control signal to the desaturation detection unit and the push-pull amplification unit based on the PWM signal and the signal output by the fault summary and shutdown unit, the desaturation detection unit detects the drain-source voltage of the MOS tube of the SiC module under the control of the control signal output by the drive chip to determine whether the SiC module has a short circuit and obtain a first detection result, the current slope detection unit detects the voltage of the internal packaging parasitic inductance of the SiC module to determine whether the SiC module has a short circuit and obtain a second detection result, and the fault summary and shutdown unit outputs a summary signal to the push-pull amplification unit and the drive chip according to the first detection result and the second detection result to shut down the SiC module through the push-pull amplification unit when the SiC module has a short circuit and feed back to the main control DSP through the drive chip to make the main control DSP stop sending the PWM signal, so that whether the SiC module has a short circuit is determined by combining the drain-source voltage of the MOS tube of the SiC module and the voltage of the internal packaging parasitic inductance of the SiC module, and the SiC module is shut down in time when it is determined that the SiC module has a short circuit to suppress the short circuit current and improve the safety of the operation of the SiC module.

[0079] According to an embodiment of the present application, a power electronic device corresponding to the protection device of the SiC module is also provided. The power electronic device can include the protection device of the SiC module described above.

[0080] Since the processing and functions realized by the power electronic device of the present embodiment are basically corresponding to the embodiments, principles and examples of the device, the description of the present embodiment will not be elaborated on the related matters which can be referred to the relevant description in the foregoing embodiments.

[0081] According to an embodiment of the present application, a protection method of a SiC module of a power electronic device corresponding to the power electronic device is also provided, as shown in the flowchart of an embodiment of the method of the present application. Figure 7 The protection method of the SiC module of the power electronic device can include steps S110 to S170.

[0082] At step S110, the main control unit sends a PWM signal to the drive chip.

[0083] At step S120, a control signal is obtained by the driving chip based on the PWM signal and a first logic processing signal output by the logic processing unit; and a second logic processing signal and a third logic processing signal are output by the logic processing unit based on the control signal, the second logic processing signal output by the logic processing unit is output to the switching amplification unit, and the third logic processing signal output by the logic processing unit is output to the first detection unit.

[0084] At step S130, the drain-source voltage of the MOS tube is detected by the first detection unit under the action of the third logic processing signal output by the logic processing unit; and whether the SiC module is short-circuited is determined according to the drain-source voltage of the MOS tube, to obtain a first detection result.

[0085] At step S140, the voltage of the internal package parasitic inductance is detected by the second detection unit; and whether the SiC module is short-circuited is determined according to the voltage of the internal package parasitic inductance, to obtain a second detection result; and then, the logic processing unit performs logic processing in combination with the first detection result, the second detection result, and the control signal output by the driving chip, to output the first logic processing signal, the second logic processing signal, and the third logic processing signal.

[0086] At step S150, the first logic processing signal, the second logic processing signal, and the third logic processing signal are output by the logic processing unit in combination with the first detection result output by the first detection unit, the second detection result output by the second detection unit, and the control signal output by the driving chip, the first logic processing signal is output to the driving chip, the second logic processing signal output by the logic processing unit is output to the switching amplification unit, and the third logic processing signal output by the logic processing unit is output to the first detection unit.

[0087] At step S160, a turn-off signal is sent by the switching amplification unit in a case where the second logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, to control the SiC module to turn off by using the turn-off signal.

[0088] At step S170, the first logic processing signal output by the logic processing unit is fed back to the main control unit by the driving chip in a case where the first logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, to make the main control unit stop sending the PWM signal, that is, the PWM signal is stopped from being sent by the main control unit in a case where the first logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited.

[0089] like Figure 2 As shown, in the drive and short-circuit protection circuit of the SiC module (i.e., the SiC power device T1, such as a MOSFET), the main control DSP sends a PWM control signal to the drive chip within the drive and short-circuit protection circuit. After logic conversion by the drive chip, the signal is combined with the signal from the fault summary and shutdown unit to obtain an output signal, which is then output to the desaturation detection unit and the push-pull amplification unit, respectively. This output signal is used to control whether the desaturation detection unit operates. The push-pull amplification unit controls the turn-on and turn-off of the SiC power device based on this output signal. The desaturation detection unit determines whether a short circuit has occurred in the SiC power device by detecting the voltage between the drain (e.g., drain d) and source (e.g., source s') of the MOSFET, and outputs the detection result to the fault summary and shutdown unit. The current slope detection unit determines whether a short circuit has occurred in the device by detecting the voltage of the parasitic inductance (e.g., inductor Ls) inside the SiC module, and outputs the detection result to the fault summary and shutdown unit. The fault summary and shutdown unit summarizes the signals from both sources and outputs them in two ways: first, directly combining them with the output signal from the driver chip and sending it to the push-pull amplifier unit; second, feeding them back to the driver chip, which then feeds them back to the main control DSP, thereby stopping the main control DSP from sending PWM control signals. This control method and structure can improve the stability of short-circuit protection triggering when the SiC module is short-circuited, reduce the protection blind zone, and shorten the time from the occurrence of a short circuit to the shutdown of the SiC module.

[0090] like Figure 4 As shown, the desaturation detection unit includes: a high-voltage fast recovery diode D1, a Zener diode D2, an NPN transistor M1, and a high-precision current source I. A Resistors R1 and R2, blanking capacitor C4, and operational amplifier U2. When the control signal V at the base of NPN transistor M1... M1 When the voltage is high, NPN transistor M1 is turned on, and the desaturation detection unit is in a non-operating state. At this time, the voltage of blanking capacitor C4 is... For fixed voltage: Due to the voltage of blanking capacitor C4 The voltage is less than the pre-set fault detection threshold V Ref Therefore, the operational amplifier U2 outputs a high-level signal, i.e., the first detection result V. Fault1 This is a high-level signal.

[0091] When the control signal V at the base of NPN transistor M1 M1 When the voltage is low, NPN transistor M1 is turned off, and the desaturation detection unit is in operation. At this time, the voltage of blanking capacitor C4 is... V V is the voltage on the high-voltage fast-recovery diode D1. If the SiC power device is normally turned on, the voltage of the blanking capacitor C4 will also be less than the voltage threshold V Ref set in advance for fault judgment, so the output end of the operational amplifier U2 outputs a high-level signal, i.e., the first detection result V Fault1 is a high-level signal; if the SiC power device is short-circuited, the drain-source voltage V ds' of the SiC power device will increase with the current, according to the above formula, , the voltage V of L Ref will also increase, and when V Ref is greater than V Ref , the output end of the operational amplifier U2 outputs a low-level signal, i.e., the first detection result V Fault1 is a low-level signal. Among them, the current source I A , the blanking capacitor C4 and the resistor R1 can be selected and matched according to actual conditions, and the blanking time is usually set within 3us to ensure that the short-circuit protection is triggered in time.

[0092] As shown in Figure 5 , the fault summary and shutdown unit includes a voltage stabilizing tube D3, a diode D4, resistors R3, R4, R5 and R6, and an optical coupler U3. The current slope detection unit judges whether a short circuit occurs by detecting the voltage of the parasitic inductance L s inside the SiC module package, and the voltage V s of L Ls is: When the SiC power device is normally turned on, the current is normally rising, and the current slope is a small value; but when the SiC power device is short-circuited, the current will rise by several times, and the current slope is also several times of the normal current slope, according to the above formula, the voltage V s of L Ls will also increase. For example: under normal circumstances, the voltage V s of L Ls is 1V to 2V, and it will surge to 4V to 5V in short circuit. By adjusting the voltage stabilizing tube D3, the resistor R3 and the resistor R4, the threshold value of the short-circuit protection triggering can be set. When the voltage V s of L Ls reaches a certain value, the optical coupler U3 is turned on, and the signal level of the second detection result V Fault2 changes from high level to low level. Since the size of the current slope is used to determine whether a short circuit occurs, the detection of the second type of short circuit is more timely.

[0093] In the scheme of the present application, the push-pull amplification unit is used as a controllable switch, such as a push-pull power amplifier. The push-pull amplification unit adopts a push-pull structure, for example: the push-pull structure mainly consists of an NPN transistor, a PNP transistor, and resistors and capacitors. One transistor is responsible for pulling up the output voltage, and one transistor is responsible for pulling down the output voltage, hence the name "push-pull". The main function is to improve the driving ability and reduce signal distortion.

[0094] In the scheme of the present application, by detecting the changes of SiC modules at different positions when short circuit occurs, and according to the detection results, the SiC module is quickly turned off, so as to realize the suppression of short circuit current, effectively reduce the temperature of SiC module and rear-end equipment, and improve the safety and stability of SiC module operation. At the same time, the problem of slow detection of the protection circuit of the SiC module in the related scheme when short circuit occurs is solved, the problem of protection blind area of the protection circuit of the SiC module in the related scheme when detecting is solved, and the problem of complex circuit and large delay of the protection circuit of the SiC module in the related scheme is solved.

[0095] In some embodiments, the logic processing unit includes a first logic module (such as a logic AND gate U4), a second logic module (such as a logic AND gate U5), and a third logic module (such as a logic NOT gate U6).

[0096] In step S150, the logic processing unit combines the first detection result output by the first detection unit, the second detection result output by the second detection unit, and the control signal output by the driving chip to perform logic processing, and outputs the first logic processing signal, the second logic processing signal, and the third logic processing signal. The specific process is described in the following example.

[0097] The following will be described in conjunction with Figure 8 The following will be described in conjunction with

[0098] In step S210, the first logic module performs AND logic processing based on the first detection result and the second detection result to obtain the first logic processing signal output by the logic processing unit, and outputs the first logic processing signal output by the logic processing unit to the driving chip.

[0099] Step S220, through the second logic module, based on the first logic processing signal output by the logic processing unit and the control signal, the logic processing unit outputs the second logic processing signal by performing AND logic processing, and outputs the second logic processing signal output by the logic processing unit to the switching amplification unit.

[0100] Step S230, through the third logic module, based on the second logic processing signal output by the logic processing unit, the logic processing unit outputs the third logic processing signal by performing non-logic processing, and outputs the third logic processing signal output by the logic processing unit to the first detection unit.

[0101] As shown in Figure 6 The fault summary and shutdown unit includes: logic AND gate U4 and logic AND gate U5, logic NOT gate U6. The logic AND gate U4 receives the level signals output by the desaturation detection unit and the current slope detection unit, such as the first detection result V Fault1 And the second detection result V Fault2 Only when both are high (i.e. no short circuit), the logic AND gate U4 outputs high level; if one or more is low (i.e. short circuit), the logic AND gate U4 outputs low level. The output signal of the logic AND gate U4 is sent to the drive chip U1, and then fed back to the master control DSP by the drive chip U1 to make the master control DSP stop sending PWM wave; secondly, the output signal of the logic AND gate U4 is outputted through the logic AND gate U5 and the control signal output by the drive chip U1, and when there is a short circuit, the voltage at the input end of the push-pull amplification unit is quickly pulled down, so that the SiC module is quickly disconnected. The output signal of the logic AND gate U5 is used to control whether the desaturation detection unit works after passing through the logic NOT gate U6. Compared with the related scheme in which the fault signal is fed back to the master control DSP, and then the master control DSP closes the wave (i.e. closes the PWM signal), in the scheme of the present application, the logic circuit is used to shut down in advance, which can reduce the delay of closing the wave and reduce the short circuit time of the SiC module.

[0102] In the scheme of the present application, the fast shutdown mode composed of logic circuits is used, which reduces the delay of triggering the gate shutdown after detecting the short circuit. In this way, the fast shutdown mode composed of logic circuits is adopted, the circuit is simple and the response speed is fast, which can effectively reduce the risk of heating damage or failure of the SiC module caused by too long short circuit time when the SiC module short circuit occurs, and improve the service life of the SiC module.

[0103] Since the processing and functions realized by the method of the present embodiment are basically corresponding to the foregoing embodiments, principles and examples of the power electronic device, the description of the present embodiment will not be described in detail, and the related description in the foregoing embodiments can be referred to, which will not be described herein.

[0104] In summary, the person skilled in the art can easily understand that the above-mentioned advantageous modes can be freely combined and superimposed without conflict.

[0105] The above merely provides an example of the present application, but is not intended to limit the present application. The present application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall fall within the scope of claims of the present application.

Claims

1. A protection device for a SiC module, characterized in that, The SiC module has a MOSFET and an internally packaged parasitic inductor; the protection device of the SiC module is disposed between the driver chip of the SiC module and the SiC module; the driver chip is controlled by the main control unit of the driver chip; The protection device of the SiC module includes: a first detection unit, a second detection unit, a logic processing unit, and a switching amplification unit; the second detection unit includes: a second sampling resistor module, a second current-limiting resistor module, an output resistor module, and an optocoupler module; wherein, the source auxiliary terminal of the MOS transistor is connected to the first connection terminal of the second sampling resistor module; the second connection terminal of the second sampling resistor module can be connected to the anode of the diode side of the optocoupler module; the source main terminal of the MOS transistor is connected to the cathode of the diode side of the optocoupler module; a preset DC power supply, after passing through the second current-limiting resistor module, is connected to the collector of the transistor side of the optocoupler module; the collector of the transistor side of the optocoupler module, after passing through the output resistor module, outputs the second detection result; the emitter of the transistor side of the optocoupler module is grounded; the logic processing unit can output a first logic processing signal, a second logic processing signal, and a third logic processing signal; wherein... The main control unit is used to send PWM signals to the driver chip; The driver chip is used to obtain a control signal based on the PWM signal and the first logic processing signal output by the logic processing unit; The first detection unit is used to detect the drain-source voltage of the MOS transistor under the action of the third logic processing signal output by the logic processing unit; and to determine whether the SiC module is short-circuited based on the drain-source voltage of the MOS transistor, thereby obtaining a first detection result; The second detection unit is used to detect the voltage of the internal package parasitic inductor; and to determine whether the SiC module is short-circuited based on the voltage of the internal package parasitic inductor, thereby obtaining a second detection result; The logic processing unit is used to combine the first detection result output by the first detection unit, the second detection result output by the second detection unit, and the control signal output by the driver chip to perform logic processing, and output a first logic processing signal, a second logic processing signal, and a third logic processing signal. The switching amplification unit is used to issue a shutdown signal when the second logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, so as to control the SiC module to shut down using the shutdown signal. The driver chip is also configured to, when the first logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, feed back the first logic processing signal output by the logic processing unit to the main control unit so that the main control unit stops sending the PWM signal.

2. The protection device for the SiC module according to claim 1, characterized in that, The first detection unit includes: a first diode module, a first sampling resistor module, a first current-limiting resistor module, a comparator module, and a switching transistor module; wherein, The drain of the MOS transistor is connected to the cathode of the first diode module; the anode of the first diode module is sampled by the first sampling resistor module to obtain the drain-source voltage of the MOS transistor and then input to the inverting input terminal of the comparator module; a preset voltage threshold is input to the non-inverting input terminal of the comparator module; the output terminal of the comparator module can output the first detection result. The control terminal of the switching transistor module is used to receive the third logic processing signal; the first connection terminal of the switching transistor module is connected to the source auxiliary terminal of the MOS transistor; the second connection terminal of the switching transistor module is connected to the inverting input terminal of the comparator module after passing through the first current limiting resistor module.

3. The protection device for the SiC module according to claim 2, characterized in that, The first detection unit further includes at least one of the following: a first Zener diode module and a blanking capacitor module; wherein, The inverting input terminal of the comparator module is connected to the cathode of the first Zener diode module; the anode of the first Zener diode module is connected to the source auxiliary terminal of the MOS transistor. The inverting input terminal of the comparator module is connected to the source auxiliary terminal of the MOS transistor after passing through the blanking capacitor module. Specifically, when the control signal output by the driver chip is a low-level signal, the first detection unit is in a non-operating state; when the control signal output by the driver chip is a high-level signal, the first detection unit is in an operating state: when the drain-source voltage of the MOS transistor is less than a preset voltage threshold, the comparison module outputs a high-level signal to indicate that the SiC module is not short-circuited, which is taken as the first detection result; when the drain-source voltage of the MOS transistor is greater than the preset voltage threshold, the comparison module outputs a low-level signal to indicate that the SiC module is short-circuited, which is taken as the first detection result.

4. The protection device for the SiC module according to claim 1, characterized in that, The second detection unit further includes at least one of the following: a second Zener diode module, a second diode module, and a reference resistor module; wherein, The second connection terminal of the second sampling resistor module is connected to the cathode of the second Zener diode module; the anode of the second Zener diode module is connected to the anode of the diode side of the optocoupler module. The second connection terminal of the second sampling resistor module is connected to the source main terminal of the MOS transistor after passing through the reference resistor module; The second connection terminal of the second sampling resistor module is connected to the cathode of the second diode module; the anode of the second diode module is connected to the main source terminal of the MOS transistor. Specifically, if the voltage corresponding to the current slope of the internally packaged parasitic inductor is less than a preset voltage threshold, the optocoupler module is not turned on, and the output terminal of the optocoupler module is a high-level signal, indicating that the SiC module is not short-circuited, which is the second detection result; if the voltage corresponding to the current slope of the internally packaged parasitic inductor is greater than the preset voltage threshold, the optocoupler module is turned on, and the output terminal of the optocoupler module is a low-level signal, indicating that the SiC module is short-circuited, which is the second detection result.

5. The protection device for the SiC module according to any one of claims 1 to 4, characterized in that, The logic processing unit includes: a first logic module, a second logic module, and a third logic module; wherein, The logic processing unit performs logic processing on the first detection result output by the first detection unit, the second detection result output by the second detection unit, and the control signal output by the driver chip, and outputs a first logic processing signal, a second logic processing signal, and a third logic processing signal, including: The first logic module is used to perform AND logic processing based on the first detection result and the second detection result to obtain the first logic processing signal output by the logic processing unit; The second logic module is used to perform AND logic processing on the first logic processing signal output by the logic processing unit and the control signal to obtain the second logic processing signal output by the logic processing unit. The third logic module is used to perform non-logic processing based on the second logic processing signal output by the logic processing unit to obtain the third logic processing signal output by the logic processing unit.

6. The protection device for the SiC module according to any one of claims 1 to 4, characterized in that, The switching amplification unit includes a push-pull power amplifier.

7. The protection device for the SiC module according to claim 5, characterized in that, The switching amplification unit includes a push-pull power amplifier.

8. A power electronic device, characterized in that, include: The protection device for the SiC module as described in any one of claims 1 to 7.

9. A method for protecting a SiC module corresponding to the protection device of a SiC module as described in any one of claims 1 to 7, characterized in that, include: Send a PWM signal to the driver chip; The control signal is obtained by the driver chip based on the PWM signal and the first logic processing signal output by the logic processing unit. The first detection unit detects the drain-source voltage of the MOS transistor under the action of the third logic processing signal output by the logic processing unit; and determines whether the SiC module is short-circuited based on the drain-source voltage of the MOS transistor, thereby obtaining the first detection result. The second detection unit detects the voltage of the internally packaged parasitic inductor and determines whether the SiC module is short-circuited based on the voltage of the internally packaged parasitic inductor, thus obtaining a second detection result. The logic processing unit combines the first detection result output by the first detection unit, the second detection result output by the second detection unit, and the control signal output by the driver chip to perform logic processing, and outputs a first logic processing signal, a second logic processing signal, and a third logic processing signal. The switching amplification unit issues a shutdown signal when the second logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, so as to control the SiC module to shut down using the shutdown signal. When the first logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, the transmission of the PWM signal is stopped.

10. The protection method for SiC modules according to claim 9, characterized in that, The logic processing unit includes: a first logic module, a second logic module, and a third logic module; wherein, The logic processing unit performs logic processing on the first detection result output by the first detection unit, the second detection result output by the second detection unit, and the control signal output by the driver chip, and outputs a first logic processing signal, a second logic processing signal, and a third logic processing signal, including: The first logic module performs AND logic processing based on the first detection result and the second detection result to obtain the first logic processing signal output by the logic processing unit. The second logic module performs AND logic processing on the first logic processing signal output by the logic processing unit and the control signal to obtain the second logic processing signal output by the logic processing unit. The third logic module performs non-logic processing on the second logic processing signal output by the logic processing unit to obtain the third logic processing signal output by the logic processing unit.

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