Protection device and method of SiC module and power electronic equipment

Abstract

The invention discloses a SiC module protection device and method and 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; the first detection unit detects the drain-source voltage of the MOS tube based on the third logic processing signal to obtain a first detection result; the second detection unit is used for detecting the voltage of the internal packaging parasitic inductor to obtain a second detection result; the logic processing unit performs processing by combining the first detection result, the second detection result and a control signal to obtain a first logic processing signal, a second logic processing signal and a 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 SiC module is timely turned off when it is judged that 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 inductor, and the safety is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power electronic equipment, and specifically relates to a protection device and method for a SiC module and a power electronic equipment, and more particularly to a detection circuit and method for short-circuit protection of a SiC MOSFET module, and a power electronic equipment having the detection circuit. Background Art

[0002] In recent years, with the development of new energy vehicles, industrial frequency conversion, rail transit, aerospace and other fields, higher requirements have been placed on the power and performance of power electronic equipment. Power semiconductor modules are a large category, which can be divided into silicon, silicon carbide, gallium nitride and other materials according to different materials. Thyristor modules (i.e. silicon carbide modules) are one type of power semiconductor modules. Silicon carbide modules (i.e. SiC modules) have gradually replaced traditional silicon modules due to their outstanding 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 stringent. Due to the high power and small chip area of ​​silicon carbide modules, the ability of silicon carbide modules to withstand current during short circuit is relatively weak. In order to ensure the normal and safe operation of power devices, various protection circuits are usually required to protect silicon carbide modules, and their protection time must be strictly controlled to reduce the risk of damage or failure of silicon carbide modules and their associated devices after short circuit.

[0004] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0005] The purpose of the present invention is to provide a protection device, method and power electronic device for a SiC module to solve the problem that the SiC module has a weak ability to withstand current when it is short-circuited, has the risk of damage or failure, and affects the operation safety, so as to achieve 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 package parasitic inductance of the SiC module, and shutting down the SiC module in time when it is judged that the SiC module is short-circuited, so as to suppress the short-circuit current and improve the safety of the operation of the SiC module.

[0006] The present invention provides a protection device for a SiC module, wherein the SiC module has a MOS tube and an internal package parasitic inductance; the protection device for the SiC module is arranged between a driving chip of the SiC module and the SiC module; the driving chip is controlled by a main control unit of the driving chip; the protection device for the SiC module comprises: a first detection unit, a second detection unit, a logic processing unit, and a switch 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 main control unit is used to send a PWM signal to the driving chip; the driving 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 tube under the action of the third logic processing signal output by the logic processing unit; and judge whether the SiC module is short-circuited according to the drain-source voltage of the MOS tube, and obtain a first detection result; the second detection unit is used to detect the voltage of the internal package parasitic inductance; and judge 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 to perform logic processing 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 driver chip, and output a first logic processing signal, a second logic processing signal, and a third logic processing signal; the switch amplifying unit is used to send 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 shutdown of the SiC module by using the shutdown signal; the driver chip is also used to feed back the first logic processing signal output by the logic processing unit to the main control unit when the first logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, so as to cause the main control unit to stop sending the PWM signal.

[0007] In some embodiments, the first detection unit includes: 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 input to the inverting input terminal of the comparison module after the drain-source voltage of the MOS tube is sampled by the first sampling resistor 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 to receive 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; the second connection terminal of the switch tube module is connected to the inverting input terminal of the comparison module after passing through the first current limiting resistor module.

[0008] In some embodiments, the first detection unit further includes at least one of the following: 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 after passing through the blanking capacitor module; wherein, when the control signal output by the driving chip is a low-level signal, the first detection unit is in a non-working state; when the control signal output by the driving chip is a high-level signal, the first detection unit is in a working state: when the drain-source voltage of the MOS tube is less than a 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; when 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 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 tube is connected to the first connection end of the second sampling resistor module; the second connection end of the second sampling resistor module can be connected to the anode on the diode side of the optocoupler module; the source main terminal of the MO tube is connected to the cathode on the diode side of the optocoupler module; a preset DC power supply is connected to the collector on the transistor side of the optocoupler module after passing through the second current limiting resistor module; the collector on the transistor side of the optocoupler module outputs the second detection result after passing through the output resistor module; the emitter on the transistor side of the optocoupler module is grounded.

[0010] In some embodiments, the second detection unit further includes at least one of the following: a second voltage stabilizing diode module, a second diode module, and a reference resistor module; wherein the second connection end of the second voltage stabilizing diode 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 resistor module is connected to the source main terminal of the MO tube after passing 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 MO tube; wherein, when the voltage corresponding to the current slope of the internal package parasitic inductance is less than a 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 package 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 includes: a first logic module, a second logic module, and a third logic module; wherein the logic processing unit performs logic processing 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 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 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; 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.

[0012] Matching the above device, the present invention further provides a power electronic device, including: the protection device of the SiC module described above.

[0013] Matching the above-mentioned power electronic device, the present invention provides a protection method for a SiC module of a power electronic device on another aspect, comprising: sending a PWM signal to the driving chip; obtaining a control signal through the driving chip based on the PWM signal and a first logic processing signal output by the logic processing unit; detecting the drain-source voltage of the MOS tube through the first detection unit under the action of a third logic processing signal output by the logic processing unit; and judging whether the SiC module is short-circuited according to the drain-source voltage of the MOS tube to obtain a first detection result; detecting the voltage of the internal package parasitic inductance through the second detection unit; and judging whether the SiC module is short-circuited according to the voltage of the internal package parasitic inductance. Whether the SiC module is short-circuited, a second detection result is obtained; 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 combined to perform logic processing, and a first logic processing signal, a second logic processing signal, and a third logic processing signal are output; through the switch amplification unit, when the second logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, a shutdown signal is sent to control the shutdown of the SiC module by 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 PWM signal is stopped from being sent.

[0014] In some embodiments, the logic processing unit includes: a first logic module, a second logic module, and a third logic module; wherein, through the logic processing unit, logic processing is performed 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 driver chip, and a first logic processing signal, a second logic processing signal, and a third logic processing signal are output, including: through the first logic module, based on the first detection result and the second detection result, and logic processing is performed to obtain the first logic processing signal output by the logic processing unit; through the second logic module, based on the first logic processing signal output by the logic processing unit and the control signal, and logic processing is performed to obtain the second logic processing signal output by the logic processing unit; through the third logic module, non-logic processing is performed 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.

[0015] Therefore, the scheme of the present invention is to set a first detection unit (such as a desaturation detection unit), a second detection unit (such as a current slope detection unit), a logic processing unit (such as a fault summary and shutdown unit), and a switch amplification unit (such as a push-pull amplification unit) between the driver chip of the SiC module and the SiC module, and the main control DSP sends a PWM signal to control the driver chip, and the driver 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 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 driver chip to determine whether the SiC module is short-circuited to obtain a first detection result, and the current slope 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 driver chip to determine whether the SiC module is short-circuited to obtain a first detection result. The element is used to detect the voltage of the internal package parasitic inductance of the SiC module to determine whether the SiC module is short-circuited to obtain a second detection result, and the fault summary and shutdown unit is used to output a summary signal to the push-pull amplifier unit and the driver chip according to the first detection result and the second detection result, so as to shut down the SiC module through the push-pull amplifier unit when the SiC module is short-circuited, and feed back to the main control DSP through the driver chip to make the main control DSP stop sending the PWM signal; thereby, by combining the drain-source voltage of the MOS tube of the SiC module and the voltage of the internal package parasitic inductance of the SiC module, it is determined whether the SiC module is short-circuited, and when it is determined that the SiC module is short-circuited, the SiC module is shut down in time 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 invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention.

[0017] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of an embodiment of a protection device for a SiC module of the present invention;

[0019] Figure 2 It is a schematic diagram of the structure of the driving and short-circuit protection circuit of the SiC module;

[0020] Figure 3 This is a schematic diagram of the electrical principle of the SiC module's drive and short-circuit protection circuit;

[0021] Figure 4 This is a schematic diagram of the electrical principle of the desaturation detection unit in the drive and short-circuit protection circuit of the SiC module;

[0022] Figure 5 This is a schematic diagram of the electrical principle of the current slope detection unit in the drive and short-circuit protection circuit of the SiC module;

[0023] Figure 6 This is a schematic diagram of the electrical principle of the fault summary and shutdown unit in the drive and short-circuit protection circuit of the SiC module;

[0024] Figure 7 A schematic diagram of a flow chart of an embodiment of a method for protecting a SiC module of the present invention;

[0025] Figure 8 The present invention is a flow chart of an embodiment of performing logic processing on 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 in the method of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] Considering that the SiC module has a weak ability to withstand current when short-circuited, there is a risk of damage or failure, which affects operational safety. There are two types of short circuits in silicon carbide modules (i.e., SiC modules): one type of short circuit is a short circuit within the bridge arm, also known as "straight-through", which is caused by the simultaneous opening of two power devices in a bridge arm. Due to the small inductance in the loop, the current rises very quickly during a short circuit, that is, the current slope is large; the second type of short circuit is a short circuit between bridge arms, generally between bridge arms or between bridge arms and ground. This type of short circuit has a slightly larger inductance, which is at the uH level. Therefore, when this type of short circuit occurs, the current rises slower than the first type of short circuit. In related schemes, there are several methods for detecting short circuits in SiC modules (such as SiC MOSFET modules):

[0028] The first is to detect the conduction voltage drop V between the drain and source of the MOS tube. ds Protection is performed, but there is a certain blanking time for detection, and the second type of short circuit is not detected in time. In the first method, since Vds increases with the increase of current, a short circuit is only determined to occur when Vds is greater than a certain threshold, and the second type of short circuit current rises slowly, so the time to detect the fault through Vds is also slow.

[0029] The second method is to detect the current slope of the parasitic inductance of the internal package of 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 spot.

[0030] The third method is to collect the tube pressure drop V of the silicon carbide module ds and the on-state current I C , the protection function is realized by calculating the instantaneous power and heat loss, but because of the need for calculation, the circuit is complex and the delay is large. Since the third method requires the use of hardware for integration operation, the circuit will become complex and time-consuming.

[0031] Therefore, the solution of the present invention proposes a protection device for a SiC module, specifically a detection circuit for short-circuit protection of a SiC MOSFET module, which detects changes in different positions of the SiC module when a short circuit occurs and quickly shuts down the SiC module according to the detection results to suppress the short-circuit current and improve the safety of the SiC module operation.

[0032] According to an embodiment of the present invention, a protection device for a SiC module is provided. Figure 1 The schematic diagram of the structure of an embodiment of the device of the present invention is shown. The SiC module has a MOS tube and an internal package parasitic inductance (such as inductance Ls); the source auxiliary terminal of the MOS tube is connected to the first connection end of the internal package parasitic inductance, and the source main terminal of the MOS tube is connected to the second connection end of the internal package parasitic inductance; the protection device of the SiC module is arranged 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, such as the main control DSP. More specifically, the SiC module also has a diode; the SiC module internally contains a MOS tube and a diode (collectively referred to as SiC power device T1), and a parasitic inductance Ls parasitic between the source auxiliary terminal of the MOS tube and the source main terminal of the MOS tube. s . Figure 2 This is a schematic diagram of the structure of the SiC module's drive and short-circuit protection circuit. 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 a gate of a MOS tube, d is a drain of the MOS tube, s' is a source auxiliary terminal of the MOS tube, and s is a source main terminal of the MOS tube; L s is the parasitic inductance of the SiC module package. Figure 1 As shown, the protection device of the SiC module includes: a first detection unit (such as Figure 2 The desaturation detection unit shown), the second detection unit (such as Figure 2 The current slope detection unit shown), the logic processing unit (such as Figure 2 Fault summary and shutdown unit shown), and switch amplification unit (such as Figure 2The logic processing unit can output a first logic processing signal, a second logic processing signal and a third logic processing signal.

[0033] Wherein, the main control unit is used to send a PWM signal to the driving chip.

[0034] The driving 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; and based on the control signal, output a second logic processing signal and a third logic processing signal after passing through the logic processing unit, output the second logic processing signal output by the logic processing unit to the switch amplifying 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 used 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 used to detect the voltage of the internal package parasitic inductance; and judge whether the SiC module is short-circuited according to the voltage of the internal package parasitic inductance to obtain a second detection result; further, the logic processing unit can perform logic processing in combination with the first detection result, the second detection result, and the control signal output by the driving chip, and output a first logic processing signal, a second logic processing signal, and a third logic processing signal.

[0037] The logic processing unit is used to perform 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, output a first logic processing signal, a second logic processing signal, and a third logic processing signal, output the first logic processing signal to the driver chip, output the second logic processing signal output by the logic processing unit to the switch amplification unit, and output the third logic processing signal output by the logic processing unit to the first detection unit.

[0038] The switch amplifying unit is used to send 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 shutdown of the SiC module by using the shutdown signal.

[0039] The driving chip is further configured to feed back the first logic processing signal output by the logic processing unit to the main control unit when the first logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, 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. Figure 2 As shown in the figure, the driving and short-circuit protection circuit of the SiC module is mainly composed of the main control DSP, SiC power devices (i.e. SiC modules), and the driving and short-circuit protection circuit, wherein the driving and short-circuit protection circuit includes a driving 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 driving and short-circuit protection circuit of the SiC module is as follows Figure 3 In order to make those skilled in the art understand the embodiments of the present invention more clearly, the following is a detailed description of the embodiments of the present invention. Figure 4 , Figure 5 and Figure 6 In the example shown, the driving and short-circuit protection circuit of the SiC module is divided into three parts for a clear and complete description. Figure 4 Schematic diagram of the electrical principle 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., the SiC power device T1 such as a MOS tube), the main control DSP sends a PWM control signal to the driving chip in the driving and short-circuit protection circuit. After the driving chip performs logic conversion, the signal is combined with the signal of the fault summary and shutdown unit to obtain an output signal and output it to the desaturation detection unit and the push-pull amplifier unit respectively. The output signal is used to control whether the desaturation detection unit works. The push-pull amplifier unit controls the opening and closing of the SiC power device according to the output signal. The desaturation detection unit determines whether the SiC power device is short-circuited 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 SiC power device to obtain a detection result, and outputs the detection result to the fault summary and shutdown unit. The current slope detection unit determines whether the device is short-circuited by detecting the voltage of the internal package parasitic inductance (such as the inductance Ls) of the SiC module, and outputs the detection result to the fault summary and shutdown unit. The fault aggregation and shutdown unit aggregates the above two signals, and then directly combines them with the output signal of the driver chip and outputs them to the push-pull amplifier unit, and then feeds them back to the driver chip, which then feeds them back to the main control DSP, so that the main control DSP stops 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 to a certain extent, reduce the protection blind area, and reduce the time from the occurrence of SiC module short-circuit to the entire process of shutting down the SiC module.

[0042] In the solution of the present invention, by detecting the changes in different positions of the SiC module when a short circuit occurs, and quickly shutting down the SiC module according to the detection results, the short-circuit current is suppressed, the temperature of the SiC module and the back-end equipment is effectively reduced, and the safety and stability of the SiC module operation are improved. At the same time, the problem of the protection circuit of the SiC module in the related solution not being able to detect the short circuit in time is solved, the problem of the protection circuit of the SiC module in the related solution having a protection blind spot during detection is solved, and the problem of the protection circuit of the SiC module in the related solution 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 resistor module (such as a resistor R1), a first current limiting resistor module (such as a resistor R2), a comparison module (such as an operational amplifier U2), and a switch tube module (such as an NPN transistor M1). The resistor R1 can control the blanking time during a short circuit by changing the resistance value. The resistor R2 is a current limiting resistor to prevent the NPN transistor M1 from being damaged by too much current when it is working.

[0044] 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; the preset voltage threshold (such as the voltage threshold V Ref ), which 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 (such as the base of the NPN transistor M1) is used to receive the third logic processing signal (such as the control signal V M1 ); the first connection end of the switch tube module (such as the emitter of the NPN transistor M1) is connected to the source auxiliary terminal of the MOS tube; the second connection end of the switch tube module (such as the collector of the NPN transistor M1) is connected to the inverting input end of the comparison module after passing through the first current limiting resistor module.

[0045] In the solution of the present invention, the first detection unit is used to determine the conduction voltage drop V between the drain and source of the MOS tube. ds Whether the preset voltage threshold is exceeded is beneficial to improving the detection speed of SiC module short-circuit detection and reducing the protection blind area.

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

[0047] Wherein, the inverting input terminal of the comparison module is connected to the cathode of the first voltage zener diode module; the anode of the first voltage zener 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 after passing through the blanking capacitor module. Wherein, when the control signal output by the driving chip is a low-level signal, the first detection unit is in a non-working state; when the control signal output by the driving chip is a high-level signal, the first detection unit is in a working state: when the drain-source voltage of the MOS tube is less than a 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; when 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] exist Figure 3 Based on this, the principle of the desaturation detection unit in the drive and short-circuit protection circuit of the SiC module is as follows Figure 4 As shown. Figure 4As shown, the desaturation detection unit includes: a high-voltage fast recovery diode D1, a voltage regulator 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. Among them, the control signal V M1 The input is to the base of the NPN transistor M1, the emitter of the NPN transistor M1 is connected to the source auxiliary terminal s' of the MOS tube, and the collector of the NPN transistor 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 source auxiliary terminal s' of the MOS tube through the high-precision current source I A After that, it is connected to the cathode of the voltage zener diode D2; the anode of the voltage zener 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; the inverting input terminal of the operational amplifier U2 is also connected to the cathode of the voltage zener diode D2, and the common end of the resistor R2 and the blanking capacitor C4. Voltage threshold V Ref , input to the non-inverting input terminal of the operational amplifier U2; the output terminal of the operational amplifier U2 outputs the first detection result V Fault1 .

[0049] When the control signal V M1 When it is high level, the NPN transistor M1 is turned on, and the desaturation detection unit is in a non-working state. At this time, the voltage V C4 For a fixed voltage: V C4 =I A × R2. Due to the voltage V C4 Less than the voltage threshold V for fault judgment set in advance Ref Therefore, the output terminal of the operational amplifier U2 outputs a high level signal, that is, the first detection result V Fault1 A high level signal.

[0050] When the control signal V M1 When it is low level, the NPN transistor M1 is turned off, and the desaturation detection unit is in working state. At this time, the voltage V C4 for:

[0051] V C4 =V R1 +V D1 +V ds' . V R1 is the voltage on resistor R1, V D1 is the voltage on the high-voltage fast recovery diode D1. If the SiC power device is turned on normally, the voltage VC4 It will also be lower than the voltage threshold V set in advance for fault judgment. Ref Therefore, the output terminal of the operational amplifier U2 outputs a high level signal, that is, 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' Will increase with the increase of current. According to the above formula, V C4 Also increases, when V C4 Greater than V Ref When the output terminal of the operational amplifier U2 outputs a low level signal, that is, the first detection result V Fault1 is a low level signal. The current source I A , blanking capacitor C4 and resistor R1 can be selected and matched according to actual conditions. 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 voltage regulator 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, and is conducive to improving the accuracy of the first detection result obtained by the first detection unit, thereby improving 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 (such as resistor R3), a second current limiting resistor module (such as resistor R5), an output resistor module (such as resistor R6), and an optical coupler module (such as optical coupler U3). 3 The voltage on resistor R4 is divided. When the optocoupler U3 is turned on, resistor R 5 It plays a role of current limiting to prevent the optical coupler U3 from being damaged. When the optical coupler U3 is turned off, the resistor R5 and the resistor R6 divide the voltage and determine the high level given to the gate U4 to the corresponding value.

[0054] Among them, the source auxiliary terminal of the MOS tube is connected to the first connection end of the second sampling resistor module; the second connection end of the second sampling resistor module can be connected to the anode on the diode side of the optocoupler module; the source main terminal of the MO tube is connected to the cathode on the diode side of the optocoupler module. A preset DC power supply (such as power supply Vcc) is connected to the collector on the transistor side of the optocoupler module after passing through the second current limiting resistor module; the collector on the transistor side of the optocoupler module outputs the second detection result after passing through the output resistor module; the emitter on the transistor side of the optocoupler module is grounded (such as ground GND).

[0055] In the solution of the present invention, the second detection unit is used to determine the current slope of the parasitic inductance of the internal package of the SiC module. Whether the current slope threshold exceeds the preset value is beneficial to improving the detection speed of the SiC module short circuit detection and reducing the protection blind area.

[0056] In the solution of the present invention, a detection circuit combining the first detection unit (such as a desaturation detection circuit) and the second detection unit (such as a current slope detection circuit) is adopted, which solves the problem of untimely detection of the second type of short circuit in related solutions, and also reduces the protection blind area, improves the stability and reliability of the short-circuit protection of the SiC module, and ensures that the circuit can be stably triggered when the SiC module is short-circuited.

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

[0058] The second connection end of the second sampling resistor 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 resistor module is connected to the source main terminal of the MO tube after passing 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 MO tube.

[0059] Among them, when the voltage corresponding to the current slope of the internal package 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 package 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.

[0060] Figure 5 This is a schematic diagram of the electrical principle of the current slope detection unit in the SiC module's drive and short-circuit protection circuit. Figure 3 Based on this, the principle of the fault aggregation and shutdown unit in the drive and short-circuit protection circuit of the SiC module is as follows Figure 5 As shown. Figure 5As shown, the fault summary and shutdown unit includes: a voltage regulator tube D3, a diode D4, resistors R3, R4, R5 and R6, and an optocoupler U3. Among them, the source auxiliary terminal s' of the MOS tube is connected to the cathode of the voltage regulator tube D3 after passing through the resistor R3; the anode of the voltage regulator tube D3 is connected to the anode of the diode side of the optocoupler U3; the cathode of the diode side of the optocoupler 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 regulator 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 optocoupler U3 after passing through the resistor R5; the emitter of the transistor side of the optocoupler U3 is grounded; the collector of the transistor side of the optocoupler U3 outputs the second detection result V after passing through the resistor R6. Fault2 .

[0061] The current slope detection unit detects the parasitic inductance L of the internal package of the SiC module. s The voltage is used to determine whether a short circuit has occurred. s The voltage V Ls for:

[0062] When the SiC power device is turned on normally, the current is normally rising, and the current slope is a small value; however, when the SiC power device is short-circuited, the current will increase geometrically, and the current slope It is also a geometric multiple of the normal current slope. According to the above formula, L s The voltage V Ls For example, under normal circumstances, L s The voltage V Ls The voltage of the short circuit protection is 1V to 2V, and it will surge to 4V to 5V when short circuit occurs. The threshold of short circuit protection triggering can be set by adjusting the voltage regulator D3, resistor R3, and resistor R4. s The voltage V Ls After reaching a certain value, the optocoupler U3 is turned on, and the second detection result V Fault2 The signal level changes from high level to low level. Since the short circuit is determined by the current slope, the detection of the second type of short circuit is more timely.

[0063] In the solution of the present invention, a second voltage stabilizing diode module, a second diode module, and a reference resistor module are provided in the second detection unit, which can better protect the safety of the second detection unit itself, and is conducive to improving the accuracy of the second detection result obtained by the second detection unit, thereby improving the accuracy of the short circuit judgment of the SiC module.

[0064] In the solution of the present invention, the conduction voltage drop V between the drain and source of the MOS tube is used. dsand the current slope of the parasitic inductance of the SiC module package The combined short-circuit detection circuit can not only improve the detection speed and reliability of short-circuit detection, but also reduce the protection blind area.

[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 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:

[0067] The first logic module is used to perform 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 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 output the second logic processing signal output by the logic processing unit to the switch amplification unit.

[0069] The third logic module is used to perform non-logical processing based on the second logic processing signal output by the logic processing unit to obtain a 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 electrical principle 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 aggregation and shutdown unit in the drive and short-circuit protection circuit of the SiC module is as follows Figure 6 As shown. Figure 6 As shown, the fault summary and shutdown unit includes: logic AND gate U4 and logic AND gate U5, and logic NOT gate U6. Among them, the first input end of the driver chip U1 is used to receive the PWM signal, the second input end of the driver chip U1 is used to receive the output signal (i.e., Fault signal) of the fault summary and shutdown unit, the first output end of the driver chip U1 is connected to the input end of the push-pull amplifier unit, and the second output end of the driver chip U1 is connected to the input end of the main control DSP. The driver chip U1 can use a chip with model number IC1ED020I12.

[0071] The first output terminal of the driving chip U1 is connected to the first input terminal of the logic AND gate U5; the first detection result V Fault1 Input to the first input terminal of the logic AND gate U4, the second detection result V Fault2 The output of the logic AND gate U4 is connected to the second input of the driver chip U1. The output of the logic AND gate U4 is also connected to the second input of the logic AND gate U5. The output of the logic AND gate U5 is connected to the input of the push-pull amplifier unit. The output of the push-pull amplifier unit is connected to the gate g of the MOS tube. The output of the logic AND gate U5 is also connected to the input of the logic NOT gate U6. The output of the logic NOT gate U6 outputs the control signal V M1 To the base of NPN transistor M1.

[0072] like Figure 6 As shown, the logic gate U4 receives the level signal 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 level (i.e. no short circuit), the logic AND gate U4 outputs high level; if more than one is low level (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 driver chip U1, and then fed back to the main control DSP by the driver chip U1 to stop the main control DSP from sending PWM waves; the second is to output after being ANDed with the control signal output by the driver 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 amplifier unit can be quickly lowered, so that 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 passing 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 turns off the wave (i.e. turns off the PWM signal), the scheme of the present invention uses a logic circuit for early shutdown, which can reduce the delay of turning off the wave and reduce the short circuit time of the SiC module.

[0073] In the solution of the present invention, a fast shutdown method composed of a logic circuit is used to reduce the delay of triggering gate shutdown after a short circuit is detected. In this way, a fast shutdown method composed of a logic circuit is adopted, the circuit is simple and the response speed is fast, and the risk of heat damage or failure of the SiC module due to a long short circuit time can be effectively reduced when a short circuit occurs in the SiC module, thereby increasing the service life of the SiC module.

[0074] In some implementations, the switch amplification unit includes: a push-pull power amplifier.

[0075] In the solution of the present invention, the push-pull amplifier unit is used as a controllable switch, such as a push-pull power amplifier. The push-pull amplifier unit adopts a push-pull structure, for example: the push-pull structure is mainly composed of an NPN transistor, a PNP transistor, a resistor and a capacitor. One transistor is responsible for pulling up the output voltage, and the other transistor is responsible for pulling down the output voltage, so it is called "push-pull", and its 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 MOSFET power devices 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 (such as transformers) with fast response speed and isolation measures. The above embodiment includes parameter demonstrations of specific values, 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 actual conditions.

[0077] In the scheme of the present invention, a detection circuit combining current source-based drain-source voltage detection and optocoupler isolation-based inductor current change rate detection is adopted. Compared with the detection methods such as the inductor current change rate detection based on integration in the related schemes, the entire detection circuit loop is simpler, the circuit delay is low, and the detection of short circuits is faster and more reliable. After the short circuit fault is detected, first, it is directly combined with the output signal of the driver chip U1 and then output to the push-pull amplifier unit, and second, it is fed back to the driver chip U1, and then fed back to the main control DSP by the driver chip U1, so that the main control DSP stops sending PWM waves. A fast shutdown method composed of a logic circuit is used. When a short circuit is detected, the control signal of the power device can be directly turned off, reducing the delay from detection to triggering the gate shutdown.

[0078] According to the technical solution of the present invention, a desaturation detection unit, a current slope detection unit, a fault summary and shutdown unit, and a push-pull amplification unit are arranged between a driving chip of a SiC module and the SiC module. The main control DSP sends a PWM signal to control the driving chip. The driving 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 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 is short-circuited to obtain a first detection result. The current slope detection unit is used to detect the internal packaging parasitic voltage of the SiC module. The voltage of the inductor is used to determine whether the SiC module is short-circuited to obtain a second detection result, and the fault summary and shutdown unit is used to output a summary signal to the push-pull amplifier unit and the driver chip according to the first detection result and the second detection result, so as to shut down the SiC module through the push-pull amplifier unit when the SiC module is short-circuited, and feed back to the main control DSP through the driver chip to make the main control DSP stop sending the PWM signal; thereby, by combining the drain-source voltage of the MOS tube of the SiC module and the voltage of the internal package parasitic inductance of the SiC module, it is determined whether the SiC module is short-circuited, and the SiC module is shut down in time when it is determined that the SiC module is short-circuited, so as 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 invention, a power electronic device corresponding to a protection device of a SiC module is also provided. The power electronic device may include: the protection device of the SiC module described above.

[0080] Since the processing and functions implemented by the power electronic device of this embodiment basically correspond to the embodiments, principles and examples of the device, for the details not described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments, and no further elaboration will be made here.

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

[0082] In step S110, a PWM signal is sent to the driving chip through the main control unit.

[0083] At step S120, a control signal is obtained through the driving chip based on the PWM signal and the first logic processing signal output by the logic processing unit; and based on the control signal, a second logic processing signal and a third logic processing signal are output after passing through the logic processing unit, the second logic processing signal output by the logic processing unit is output to the switch amplifying 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 based on the voltage of the internal package parasitic inductance to obtain a second detection result; 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 driver chip, and outputs a first logic processing signal, a second logic processing signal, and a third logic processing signal.

[0086] At step S150, the logic processing unit performs logic processing 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 driver chip, outputs a first logic processing signal, a second logic processing signal, and a third logic processing signal, outputs the first logic processing signal to the driver chip, outputs the second logic processing signal output by the logic processing unit to the switch amplification unit, and outputs the third logic processing signal output by the logic processing unit to the first detection unit.

[0087] At step S160 , the switch amplifying 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 shutdown of the SiC module by using the shutdown signal.

[0088] At step S170, when the first logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, the first logic processing signal output by the logic processing unit is fed back to the main control unit through the driving chip, so that the main control unit stops sending the PWM signal, that is, when the first logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, the main control unit stops sending the PWM signal.

[0089] like Figure 2 As shown, in the driving and short-circuit protection circuit of the SiC module (i.e., the SiC power device T1 such as a MOS tube), the main control DSP sends a PWM control signal to the driving chip in the driving and short-circuit protection circuit. After the driving chip performs logic conversion, the signal is combined with the signal of the fault summary and shutdown unit to obtain an output signal and output it to the desaturation detection unit and the push-pull amplifier unit respectively. The output signal is used to control whether the desaturation detection unit works. The push-pull amplifier unit controls the opening and closing of the SiC power device according to the output signal. The desaturation detection unit determines whether the SiC power device is short-circuited 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 SiC power device to obtain a detection result, and outputs the detection result to the fault summary and shutdown unit. The current slope detection unit determines whether the device is short-circuited by detecting the voltage of the internal package parasitic inductance (such as the inductance Ls) of the SiC module, and outputs the detection result to the fault summary and shutdown unit. The fault aggregation and shutdown unit aggregates the above two signals, and then directly combines them with the output signal of the driver chip and outputs them to the push-pull amplifier unit, and then feeds them back to the driver chip, which then feeds them back to the main control DSP, so that the main control DSP stops 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 to a certain extent, reduce the protection blind area, and reduce the time from the occurrence of SiC module short-circuit to the entire process of shutting down the SiC module.

[0090] like Figure 4 As shown, the desaturation detection unit includes: a high-voltage fast recovery diode D1, a voltage regulator 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 M1 When it is high level, the NPN transistor M1 is turned on, and the desaturation detection unit is in a non-working state. At this time, the voltage V C4 For a fixed voltage: V C4 =I A × R2. Due to the voltage V C4 Less than the voltage threshold V for fault judgment set in advance Ref Therefore, the output terminal of the operational amplifier U2 outputs a high level signal, that is, the first detection result V Fault1 A high level signal.

[0091] When the control signal V M1When it is low level, the NPN transistor M1 is turned off, and the desaturation detection unit is in working state. At this time, the voltage V C4 =V C4 =V R1 +V D1 +V ds' . V R1 is the voltage on resistor R1, V D1 is the voltage on the high-voltage fast recovery diode D1. If the SiC power device is turned on normally, the voltage V C4 It will also be lower than the voltage threshold V set in advance for fault judgment. Ref Therefore, the output terminal of the operational amplifier U2 outputs a high level signal, that is, 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' Will increase with the increase of current. According to the above formula, V C4 Also increases, when V C4 Greater than V Ref When the output terminal of the operational amplifier U2 outputs a low level signal, that is, the first detection result V Fault1 is a low level signal. The current source I A , blanking capacitor C4 and resistor R1 can be selected and matched according to actual conditions. Usually the blanking time is set within 3us to ensure that the short-circuit protection is triggered in time.

[0092] like Figure 5 As shown in FIG. 1 , the fault summary and shutdown unit includes: a voltage regulator tube D3, a diode D4, resistors R3, R4, R5 and R6, and an optocoupler U3. The current slope detection unit detects the parasitic inductance L of the internal package of the SiC module. s The voltage is used to determine whether a short circuit has occurred. s The voltage V Ls for: When the SiC power device is turned on normally, the current is normally rising, and the current slope is a small value; however, when the SiC power device is short-circuited, the current will increase geometrically, and the current slope It is also a geometric multiple of the normal current slope. According to the above formula, L s The voltage V Ls For example, under normal circumstances, L s The voltage V Ls The voltage is 1V to 2V, and it will surge to 4V to 5V when short-circuited. The threshold for triggering the short-circuit protection can be set by adjusting the voltage regulator D3, resistor R3, and resistor R4. s The voltage V LsAfter reaching a certain value, the optocoupler U3 is turned on, and the second detection result V Fault2 The signal level changes from high level to low level. Since the short circuit is determined by the current slope, the detection of the second type of short circuit is more timely.

[0093] In the solution of the present invention, the push-pull amplifier unit is used as a controllable switch, such as a push-pull power amplifier. The push-pull amplifier unit adopts a push-pull structure, for example: the push-pull structure is mainly composed of an NPN transistor, a PNP transistor, a resistor and a capacitor. One transistor is responsible for pulling up the output voltage, and the other transistor is responsible for pulling down the output voltage, so it is called "push-pull", and its main function is to improve the driving ability and reduce signal distortion.

[0094] In the solution of the present invention, by detecting the changes in different positions of the SiC module when a short circuit occurs, and quickly shutting down the SiC module according to the detection results, the short-circuit current is suppressed, the temperature of the SiC module and the back-end equipment is effectively reduced, and the safety and stability of the SiC module operation are improved. At the same time, the problem of the protection circuit of the SiC module in the related solution not being able to detect the short circuit in time is solved, the problem of the protection circuit of the SiC module in the related solution having a protection blind spot during detection is solved, and the problem of the protection circuit of the SiC module in the related solution being complex and having a large delay is solved.

[0095] 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 ).

[0096] In step S150, the logic processing unit performs logic processing 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 driver chip to output the first logic processing signal, the second logic processing signal, and the third logic processing signal. For the specific process, please refer to the following exemplary description.

[0097] Combine the following Figure 8 The method of the present invention is shown as a flow chart of an embodiment of performing logical processing 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 driver chip, further illustrating the specific process of performing logical processing 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 driver chip in step S150, including: steps S210 to S230.

[0098] Step S210: Performing logic processing based on the first detection result and the second detection result through the first logic module to obtain a first logic processing signal output by the logic processing unit, and outputting the first logic processing signal output by the logic processing unit to the driver chip.

[0099] Step S220, performing logic processing based on the first logic processing signal output by the logic processing unit and the control signal through the second logic module to obtain a second logic processing signal output by the logic processing unit, and outputting the second logic processing signal output by the logic processing unit to the switch amplification unit.

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

[0101] like Figure 6 As shown, the fault summary and shutdown unit includes: logic AND gates U4 and U5, and logic NOT gate U6. The logic AND gate U4 receives the level signal 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 level (i.e. no short circuit), the logic AND gate U4 outputs high level; if more than one is low level (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 driver chip U1, and then fed back to the main control DSP by the driver chip U1 to stop the main control DSP from sending PWM waves; the second is to output after being ANDed with the control signal output by the driver 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 amplifier unit can be quickly lowered, so that 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 passing 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 turns off the wave (i.e. turns off the PWM signal), the scheme of the present invention uses a logic circuit for early shutdown, which can reduce the delay of turning off the wave and reduce the short circuit time of the SiC module.

[0102] In the solution of the present invention, a fast shutdown method composed of a logic circuit is used to reduce the delay of triggering gate shutdown after a short circuit is detected. In this way, a fast shutdown method composed of a logic circuit is adopted, the circuit is simple and the response speed is fast, and the risk of heat damage or failure of the SiC module due to a long short circuit time can be effectively reduced when a short circuit occurs in the SiC module, thereby increasing the service life of the SiC module.

[0103] Since the processing and functions implemented by the method of this embodiment basically correspond to the embodiments, principles and examples of the aforementioned power electronic equipment, for the details not fully described in this embodiment, reference can be made to the relevant descriptions in the aforementioned embodiments, and no further elaboration will be made here.

[0104] 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.

[0105] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A protection device for a SiC module, characterized in that: The SiC module has a MOS tube and an internal package parasitic inductance; the protection device of the SiC module is arranged 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 comprises: a first detection unit, a second detection unit, a logic processing unit, and a switch 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 main control unit is used to send a PWM signal to the driving chip; The driving 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 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; The second detection unit is used to detect the voltage of the internal package parasitic inductance; and determine 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 to perform 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 output a first logic processing signal, a second logic processing signal, and a third logic processing signal; The switch amplifying unit is used to send 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 shutdown of the SiC module by using the shutdown signal; The driving chip is further configured to feed back the first logic processing signal output by the logic processing unit to the main control unit when the first logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, so that the main control unit stops sending the PWM signal.

2. The protection device for 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 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; the 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 end of the switch tube module is used to receive the third logic processing signal; the first connection end of the switch tube module is connected to the source auxiliary terminal of the MOS tube; the second connection end of the switch tube module is connected to the inverting input end of the comparison module after passing through the first current limiting resistor module.

3. The protection device for SiC module according to claim 2, characterized in that: The first detection unit further includes at least one of the following: 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 after passing through the blanking capacitor module; Among them, when the control signal output by the driving chip is a low-level signal, the first detection unit is in a non-working state; when the control signal output by the driving chip is a high-level signal, the first detection unit is in a working state: when the drain-source voltage of the MOS tube is less than a 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; when 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.

4. The protection device for a SiC module according to any one of claims 1 to 3, characterized in that: The second detection unit includes: a second sampling resistor module, a second current limiting resistor module, an output resistor module, and an optical coupling module; wherein, The source auxiliary terminal of the MOS tube is connected to the first connection end of the second sampling resistor module; the second connection end of the second sampling resistor module can be connected to the anode on the diode side of the optical coupling module; the source main terminal of the MO tube is connected to the cathode on the diode side of the optical coupling module; The preset DC power supply is connected to the collector on the transistor side of the optocoupler module after passing through the second current limiting resistor module; the collector on the transistor side of the optocoupler module outputs the second detection result after passing through the output resistor module; the emitter on the transistor side of the optocoupler module is grounded.

5. The protection device for SiC module according to claim 4, characterized in that: The second detection unit further includes at least one of the following: a second voltage stabilizing diode module, a second diode module, and a reference resistance module; wherein, The second connection end of the second sampling resistor 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 optical coupling module; The second connection end of the second sampling resistor module is connected to the source main terminal of the MO tube after passing 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 MO tube; Among them, when the voltage corresponding to the current slope of the internal package 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 package 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.

6. The protection device for a SiC module according to any one of claims 1 to 5, 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 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; The second logic module is used to perform AND logic processing based on the first logic processing signal output by the logic processing unit and the control signal to obtain a 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 a third logic processing signal output by the logic processing unit.

7. The protection device for a SiC module according to any one of claims 1 to 6, characterized in that: The switch amplifying unit comprises: a push-pull power amplifier.

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

9. A method for protecting a SiC module corresponding to the protection device for a SiC module according to any one of claims 1 to 7, characterized in that: include: Sending a PWM signal to the driver chip; Obtaining a control signal through the driving chip based on the PWM signal and a first logic processing signal output by the logic processing unit; By means of the first detection unit, under the action of the third logic processing signal output by the logic processing unit, the drain-source voltage of the MOS tube is detected; 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; Detecting the voltage of the internal package parasitic inductance by the second detection unit; and judging whether the SiC module is short-circuited according to the voltage of the internal package parasitic inductance to obtain a second detection result; By combining 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 logic processing unit performs logic processing to output a first logic processing signal, a second logic processing signal, and a third logic processing signal; By means of the switch amplification unit, a shutdown signal is issued 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 shutdown of the SiC module by means of the shutdown signal; When the first logic processing signal output by the logic processing unit indicates that the SiC module is short-circuited, sending the PWM signal is stopped.

10. The method for protecting a SiC module 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: By means of the first logic module, performing 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; By means of the second logic module, performing AND logic processing based on the first logic processing signal output by the logic processing unit and the control signal, to obtain a second logic processing signal output by the logic processing unit; The third logic module performs non-logic processing based on the second logic processing signal output by the logic processing unit to obtain a third logic processing signal output by the logic processing unit.

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