Short-circuit protection circuit and device for silicon carbide module

Abstract

The invention discloses a short-circuit protection circuit and device of a silicon carbide module, and relates to the technical field of silicon carbide module short-circuit protection, the short-circuit protection circuit comprises a short-circuit signal acquisition circuit, a short-circuit signal processing circuit and an oscillation signal processing circuit, the short-circuit signal processing circuit is arranged between the short-circuit signal acquisition circuit and the silicon carbide module; the oscillation signal processing circuit is connected with the short-circuit signal acquisition circuit, the short-circuit signal processing circuit and the silicon carbide module, and is configured to acquire oscillation voltage generated when the silicon carbide module is conducted, process the oscillation voltage and output the processed oscillation voltage between the short-circuit signal processing circuit and the short-circuit signal acquisition circuit; the oscillation component in the short-circuit signal output by the short-circuit signal processing circuit to the short-circuit signal acquisition circuit is suppressed. According to the protection circuit, the amplitude of short-circuit voltage during high-frequency oscillation is reduced through the oscillation signal processing circuit, overshoot voltage generated by high-frequency oscillation is suppressed, the accuracy of the short-circuit voltage is improved, and spurious triggering of short-circuit protection of the silicon carbide module is prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of short-circuit protection of silicon carbide modules, and in particular to a short-circuit protection circuit and a device for a silicon carbide module. Background Art

[0002] As the third-generation power semiconductor device, silicon carbide modules have higher operating temperature, higher operating frequency, higher power density and lower conduction loss compared with traditional silicon-based semiconductor IGBTs. Therefore, silicon carbide modules are increasingly used in power electronics, automotive electronics, photovoltaic inverters and other fields. However, both IGBT modules and silicon carbide modules require real-time monitoring and timely protection of short-circuit conditions during application, and the protection mechanism needs to be highly reliable and cannot be falsely triggered. Since the switching speed of silicon carbide modules is much faster than that of IGBTs, the current oscillation problem in the switching process is more prominent than that of IGBTs, which leads to high-frequency oscillation of the drain-source voltage during the opening process of silicon carbide modules. Therefore, silicon carbide modules are more prone to false triggering of short-circuit protection than IGBTs.

[0003] The short-circuit protection circuit in the prior art implements short-circuit protection based on the collected short-circuit voltage response of the silicon carbide module. However, the high-frequency oscillation generated by the silicon carbide module during the switching process will cause its short-circuit voltage to overshoot, increasing the collected short-circuit voltage of the silicon carbide module, which can easily lead to false triggering of the short-circuit protection of the silicon carbide module. Summary of the invention

[0004] The embodiments of the present invention provide a short-circuit protection circuit and device for a silicon carbide module to solve the technical problem in the related art that the high-frequency oscillation generated by the existing silicon carbide module during the switching process will cause its short-circuit voltage to overshoot, increase the collected short-circuit voltage of the silicon carbide module, and easily lead to the false triggering of the short-circuit protection of the silicon carbide module.

[0005] In a first aspect, a short circuit protection circuit of a silicon carbide module is provided, comprising:

[0006] Short circuit signal acquisition circuit;

[0007] A short-circuit signal processing circuit, wherein the short-circuit signal processing circuit is arranged between the short-circuit signal acquisition circuit and the silicon carbide module;

[0008] An oscillation signal processing circuit, the oscillation signal processing circuit is connected to the short-circuit signal acquisition circuit, the short-circuit signal processing circuit and the silicon carbide module, and is configured as follows:

[0009] The oscillating voltage generated when the silicon carbide module is turned on is collected, and the oscillating voltage is processed and output between the short-circuit signal processing circuit and the short-circuit signal acquisition circuit to suppress the oscillating component in the short-circuit signal output by the short-circuit signal processing circuit to the short-circuit signal acquisition circuit.

[0010] In some embodiments, the oscillation signal processing circuit includes:

[0011] An oscillation signal acquisition circuit, wherein the oscillation signal acquisition circuit is connected to the short-circuit signal processing circuit and the silicon carbide module;

[0012] An oscillation signal amplifying circuit, wherein the oscillation signal amplifying circuit is connected to the oscillation signal collecting circuit;

[0013] An oscillation signal suppression circuit is connected to the oscillation signal amplification circuit and the short-circuit signal processing circuit.

[0014] In some embodiments, the oscillation signal acquisition circuit includes:

[0015] a fourth diode D4, wherein a cathode of the fourth diode D4 is connected to the short-circuit signal processing circuit and the silicon carbide module;

[0016] a second capacitor C2, wherein a first end of the second capacitor C2 is connected to the anode of the fourth diode D4;

[0017] A third resistor R3, a first end of the third resistor R3 is connected to the second end of the second capacitor C2, and a second end of the third resistor R3 is grounded.

[0018] In some embodiments, the oscillation signal amplification circuit includes:

[0019] An operational amplifier U1, wherein a non-inverting terminal of the operational amplifier U1 is connected to a first terminal of the third resistor R3 and a second terminal of the second capacitor C2;

[0020] a fourth resistor R4, wherein a first end of the fourth resistor R4 is connected to the inverting end of the operational amplifier U1, and a second end of the fourth resistor R4 is grounded;

[0021] A fifth resistor R5, wherein a first end of the fifth resistor R5 is connected to a first end of the fourth resistor R4 and an inverting end of the operational amplifier U1, and a second end of the fifth resistor R5 is connected to an output end of the operational amplifier U1.

[0022] In some embodiments, the oscillation signal suppression circuit includes:

[0023] a sixth resistor R6, wherein a first end of the sixth resistor R6 is connected to the output end of the operational amplifier U1 and a second end of the fifth resistor R5, and a second end of the sixth resistor R6 is grounded;

[0024] A first field effect transistor Q2, wherein a gate of the first field effect transistor Q2 is connected to a first end of the sixth resistor R6, and a source of the first field effect transistor Q2 is grounded;

[0025] A third capacitor C3, a first end of the third capacitor C3 is connected to the drain of the first field effect transistor Q2, and a second end of the third capacitor C3 is grounded;

[0026] A seventh resistor R7, wherein a first end of the seventh resistor R7 is connected to a first end of the third capacitor C3 and a drain of the field effect transistor Q2, and a second end of the seventh resistor R7 is connected to the short-circuit signal processing circuit.

[0027] In some embodiments, the short-circuit signal processing circuit includes:

[0028] A first resistor R1, wherein a first end of the first resistor R1 is connected to a power source;

[0029] A first capacitor C1, wherein a first end of the first capacitor C1 is connected to a second end of the first resistor R1, and a second end of the first capacitor C1 is grounded;

[0030] a first diode D1, wherein a cathode of the first diode D1 is connected to a first end of the first capacitor C1 and a second end of the seventh resistor R7, and an anode of the first diode D1 is grounded;

[0031] A second resistor R2, wherein a first end of the second resistor R2 is connected to the cathode of the first diode D1 and a second end of the seventh resistor R7, and a second end of the second resistor R2 is connected to the silicon carbide module.

[0032] In some embodiments, the short-circuit signal acquisition circuit includes:

[0033] A driving chip, the driving chip is connected to the second end of the first resistor R1 and the first end of the first capacitor C1, and is used to compare the collected short-circuit voltage of the silicon carbide module with the short-circuit threshold voltage and act according to the comparison result.

[0034] In some embodiments, the short-circuit protection circuit of the silicon carbide module further includes:

[0035] An anti-reverse circuit is provided between the short-circuit signal processing circuit and the silicon carbide module, and is used to isolate the high voltage and the low voltage of the silicon carbide module.

[0036] In some embodiments, the anti-reverse circuit includes:

[0037] a second diode D2, wherein an anode of the second diode D2 is connected to a second end of the second resistor R2 and a cathode of the fourth diode D4;

[0038] A third diode D3, wherein an anode of the third diode D3 is connected to a cathode of the second diode D2, and a cathode of the third diode D3 is connected to the silicon carbide module.

[0039] In a second aspect, a short-circuit protection device for a silicon carbide module is provided, comprising the aforementioned short-circuit protection circuit for the silicon carbide module.

[0040] The beneficial effects brought about by the technical solution provided by the present invention include:

[0041] The embodiment of the present invention provides a short-circuit protection circuit and device for a silicon carbide module, wherein the short-circuit protection circuit includes a short-circuit signal acquisition circuit, a short-circuit signal processing circuit and an oscillation signal processing circuit, wherein the short-circuit signal processing circuit is arranged between the short-circuit signal acquisition circuit and the silicon carbide module, and the oscillation signal processing circuit is connected to the short-circuit signal acquisition circuit, the short-circuit signal processing circuit and the silicon carbide module, and is configured to: acquire the oscillation voltage generated when the silicon carbide module is turned on, and output the oscillation voltage between the short-circuit signal processing circuit and the short-circuit signal acquisition circuit after processing, so as to suppress the oscillation component in the short-circuit signal output by the short-circuit signal processing circuit to the short-circuit signal acquisition circuit. The short-circuit protection circuit of the silicon carbide module of the embodiment of the present invention reduces the amplitude of the short-circuit voltage during the high-frequency oscillation of the silicon carbide module through the oscillation signal processing circuit, suppresses the overshoot voltage generated by the high-frequency oscillation of the silicon carbide module, improves the accuracy of the short-circuit voltage of the silicon carbide module, and prevents the short-circuit protection of the silicon carbide module from being falsely triggered. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 A block diagram of a short-circuit protection circuit for a silicon carbide module provided in an embodiment of the present invention;

[0044] Figure 2 A specific block diagram of a short-circuit protection circuit of a silicon carbide module provided by an embodiment of the present invention;

[0045] Figure 3 A circuit schematic diagram of a short-circuit protection circuit for a silicon carbide module provided in an embodiment of the present invention;

[0046] Figure 4 The short-circuit voltage signal V is affected by the high-frequency oscillation of the silicon carbide module provided in the embodiment of the present invention. d ' esat Waveform diagram of

[0047] Figure 5 The short-circuit voltage signal V with suppressed oscillation components provided by the embodiment of the present invention d ” esat Waveform diagram of

[0048] Figure 6 The short-circuit voltage signal V with suppressed oscillation components provided by the embodiment of the present invention d ” esat With the oscillating voltage signal V sc Waveform diagram of . DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0050] The embodiments of the present invention provide a short-circuit protection circuit and device for a silicon carbide module, which can solve the technical problem in the related art that the high-frequency oscillation generated by the existing silicon carbide module during the switching process will cause its short-circuit voltage to overshoot, increase the collected short-circuit voltage of the silicon carbide module, and easily lead to the false triggering of the short-circuit protection of the silicon carbide module.

[0051] Figure 1 A short-circuit protection circuit for a silicon carbide module provided in an embodiment of the present invention comprises a short-circuit signal acquisition circuit, a short-circuit signal processing circuit and an oscillation signal processing circuit. The short-circuit signal processing circuit is arranged between the short-circuit signal acquisition circuit and the silicon carbide module. The oscillation signal processing circuit is connected to the short-circuit signal acquisition circuit, the short-circuit signal processing circuit and the silicon carbide module, and is configured to: acquire an oscillation voltage generated when the silicon carbide module is turned on, and output the processed oscillation voltage between the short-circuit signal processing circuit and the short-circuit signal acquisition circuit, so as to suppress the oscillation component in the short-circuit signal output by the short-circuit signal processing circuit to the short-circuit signal acquisition circuit.

[0052] The short-circuit protection circuit of the silicon carbide module of the embodiment of the present invention is provided with a short-circuit signal acquisition circuit, a short-circuit signal processing circuit and an oscillation signal processing circuit. The short-circuit signal processing circuit is arranged between the short-circuit signal acquisition circuit and the silicon carbide module. The oscillation signal processing circuit is connected with the short-circuit signal acquisition circuit, the short-circuit signal processing circuit and the silicon carbide module, and is configured to: acquire the oscillation voltage generated when the silicon carbide module is turned on, and output the oscillation voltage between the short-circuit signal processing circuit and the short-circuit signal acquisition circuit after processing, so as to suppress the oscillation component in the short-circuit signal output by the short-circuit signal processing circuit to the short-circuit signal acquisition circuit. The oscillation signal processing circuit first acquires the oscillation voltage V generated when the silicon carbide module is turned on. sc , and then through isolation, amplification and introduction of negative feedback measures, the short-circuit voltage V collected by the short-circuit signal collection circuit is desat A negative feedback is added to reduce the amplitude of the short-circuit voltage during the high-frequency oscillation of the silicon carbide module, thereby suppressing the overshoot voltage caused by the high-frequency oscillation of the silicon carbide module, improving the accuracy of the short-circuit voltage of the silicon carbide module, and preventing the short-circuit protection of the silicon carbide module from being falsely triggered.

[0053] As an optional implementation, in an embodiment of the invention, see Figure 2 As shown, the oscillation signal processing circuit includes: an oscillation signal acquisition circuit, an oscillation signal amplification circuit and an oscillation signal suppression circuit. The oscillation signal acquisition circuit is connected to the short-circuit signal processing circuit and the silicon carbide module. The oscillation signal amplification circuit is connected to the oscillation signal acquisition circuit. The oscillation signal suppression circuit is connected to the oscillation signal amplification circuit and the short-circuit signal processing circuit. The oscillation signal acquisition circuit is used to collect the oscillation voltage signal V generated when the silicon carbide module Q1 is turned on. sc , and the collected oscillation voltage signal V sc The oscillation signal amplifying circuit is used to amplify the collected high-frequency oscillation signal and output it to the oscillation signal suppression circuit, which is used to give a short-circuit voltage signal V desat Adding a negative feedback reduces the short-circuit voltage signal V desat The overshoot voltage generated by high-frequency oscillation can prevent the short-circuit protection of the silicon carbide module Q1 from being falsely triggered.

[0054] As an optional implementation, in an embodiment of the invention, see Figure 3As shown, the oscillation signal acquisition circuit includes: a fourth diode D4, a second capacitor C2 and a third resistor R3, the cathode of the fourth diode D4 is connected to the short-circuit signal processing circuit and the silicon carbide module, the first end of the second capacitor C2 is connected to the anode of the fourth diode D4, the first end of the third resistor R3 is connected to the second end of the second capacitor C2, the second end of the third resistor R3 is grounded, the silicon carbide module Q1 is a silicon carbide semiconductor field effect transistor, the cathode of the fourth diode D4 is connected to the drain of the silicon carbide module Q1, the source of the silicon carbide module Q1 is grounded, the fourth diode D4 can prevent the system blanking time from increasing due to circuit shunting, and the fourth diode D4 can also prevent the current of the oscillation signal amplification circuit and the oscillation signal suppression circuit from reverse flow, the second capacitor C2 is a DC blocking capacitor, which can enable the oscillation signal acquisition circuit to only collect the high-frequency oscillation voltage signal V of the silicon carbide module Q1 sc The AC component in the circuit avoids affecting the short-circuit voltage V desat The voltage amplitude in steady state, the third resistor R3 is a pull-down resistor and can provide a low level for the oscillation signal acquisition circuit.

[0055] As an optional implementation, in an embodiment of the invention, see Figure 3 As shown, the oscillation signal amplification circuit includes: an operational amplifier U1, a fourth resistor R4 and a fifth resistor R5, the in-phase end of the operational amplifier U1 is connected to the first end of the third resistor R3 and the second end of the second capacitor C2, the first end of the fourth resistor R4 is connected to the inverting end of the operational amplifier U1, the second end of the fourth resistor R4 is grounded, the first end of the fifth resistor R5 is connected to the first end of the fourth resistor R4 and the inverting end of the operational amplifier U1, the second end of the fifth resistor R5 is connected to the output end of the operational amplifier U1, the operational amplifier U1, the fourth resistor R4 and the fifth resistor R5 form a proportional amplification circuit, and its circuit gain is:

[0056]

[0057] The oscillation voltage signal V1 collected by the oscillation signal collection circuit can be amplified to obtain an amplified oscillation voltage signal V2, that is:

[0058]

[0059] As an optional implementation, in an embodiment of the invention, see Figure 3 and Figure 5As shown, the oscillation signal suppression circuit includes: a sixth resistor R6, a first field effect transistor Q2, a third capacitor C3 and a seventh resistor R7, the first end of the sixth resistor R6 is connected to the output end of the operational amplifier U1 and the second end of the fifth resistor R5, the second end of the sixth resistor R6 is grounded, the gate of the first field effect transistor Q2 is connected to the first end of the sixth resistor R6, the source of the first field effect transistor Q2 is grounded, the first end of the third capacitor C3 is connected to the drain of the first field effect transistor Q2, the second end of the third capacitor C3 is grounded, the first end of the seventh resistor R7 is connected to the first end of the third capacitor C3 and the drain of the field effect transistor Q2, the second end of the seventh resistor R7 is connected to the short-circuit signal processing circuit, the seventh resistor R7 is a current limiting resistor, the oscillation voltage signal V2 amplified by the oscillation signal amplification circuit turns on the first field effect transistor Q2, and the oscillation voltage flows through the first field effect transistor Q2 as an oscillation voltage signal V3 and is output to the current limiting resistor R7, giving the short-circuit signal voltage V desat Add a negative feedback so that the short-circuit signal acquisition circuit finally acquires the short-circuit voltage V d ” esat for:

[0060]

[0061] Reduces the on-state voltage V of the silicon carbide module ds During high frequency oscillation, the short circuit voltage V desat The amplitude of the short-circuit voltage signal V desat The overshoot voltage generated by the high-frequency oscillation achieves the purpose of preventing the short-circuit protection of the silicon carbide module from being falsely triggered.

[0062] As an optional implementation, in an embodiment of the invention, see Figure 4 and Figure 6 As shown, the short-circuit signal processing circuit includes: a first resistor R1, a first capacitor C1, a first diode D1 and a second resistor R2, the first end of the first resistor R1 is connected to a power supply, the first end of the first capacitor C1 is connected to the second end of the first resistor R1, the second end of the first capacitor C1 is grounded, the cathode of the first diode D1 is connected to the first end of the first capacitor C1 and the second end of the seventh resistor R7, the anode of the first diode D1 is grounded, the first end of the second resistor R2 is connected to the cathode of the first diode D1 and the second end of the seventh resistor R7, the second end of the second resistor R2 is connected to the silicon carbide module, the first resistor R1 is a pull-up resistor, the first diode D1 is a clamping diode, the second resistor R2 is a threshold adjustment resistor, and the short-circuit voltage signal output by the short-circuit signal processing circuit to the short-circuit signal acquisition circuit is:

[0063]

[0064] Where V ds is the on-state voltage of the silicon carbide module Q1, I desat Represents the current value of the acquisition end of the short-circuit signal acquisition circuit, V D represents the voltage drop of the first diode D1, and the high-frequency oscillation generated by the silicon carbide module Q1 during the switching process will cause the short-circuit voltage signal output by the short-circuit signal processing circuit to the short-circuit signal acquisition circuit to overshoot, thereby increasing the collected short-circuit voltage value V of the silicon carbide module Q1. desat , then the short-circuit voltage signal V affected by the high-frequency oscillation of the silicon carbide module Q1 d ' esat for:

[0065]

[0066] Where ΔV ds It is an oscillation component affected by the on-voltage of the silicon carbide module Q1. At this time, the short-circuit voltage signal value output by the short-circuit signal processing circuit to the short-circuit signal acquisition circuit is too large, which may easily lead to the false triggering of the short-circuit protection of the silicon carbide module Q1. Therefore, the oscillation signal suppression circuit is set at one end of the threshold adjustment resistor R2, and the oscillation voltage of the silicon carbide module Q1 is collected and amplified and output to the current limiting resistor R7, and then the threshold adjustment resistor R2 is shunted by the current limiting resistor R7, thereby suppressing the oscillation component in the short-circuit voltage signal output by the short-circuit signal processing circuit to the short-circuit signal acquisition circuit. The short-circuit voltage V d ” esat for:

[0067]

[0068] In this way, the amplitude of the short-circuit voltage during the high-frequency oscillation of the silicon carbide module Q1 is reduced, the overshoot voltage caused by the high-frequency oscillation of the silicon carbide module Q1 is suppressed, the accuracy of the short-circuit voltage of the silicon carbide module Q1 is improved, and the short-circuit protection of the silicon carbide module Q1 is prevented from being falsely triggered.

[0069] As an optional implementation, in an embodiment of the invention, see Figure 3 As shown, the short-circuit signal acquisition circuit includes: a driving chip, the driving chip is connected to the second end of the first resistor R1 and the first end of the first capacitor C1, and is used to compare the collected short-circuit voltage of the silicon carbide module with the short-circuit threshold voltage and act according to the comparison result. The driving chip is a silicon carbide driving chip, and its internal D esatIt is composed of a detection module, which mainly includes two functions. One function is to provide a constant current source to charge the first external capacitor C1. When the silicon carbide module is turned on, its on-voltage V ds Rapidly increases, the D esat The constant current source of the detection module and the external power supply VCC quickly charge the first capacitor C1 to the short-circuit protection threshold voltage, thereby shutting down the silicon carbide module Q1 for short-circuit protection; another function is to collect the short-circuit voltage signal of the silicon carbide module Q1 output by the short-circuit signal processing circuit, and compare the collected short-circuit voltage signal of the silicon carbide module Q1 with the internal threshold voltage. If the collected short-circuit voltage signal of the silicon carbide module Q1 is not less than the internal threshold voltage, it is determined that the silicon carbide module Q1 has a short-circuit fault and the silicon carbide module Q1 is shut down.

[0070] As an optional implementation, in an embodiment of the invention, see Figure 2 As shown, the short-circuit protection circuit of the silicon carbide module also includes: an anti-reverse circuit, which is arranged between the short-circuit signal processing circuit and the silicon carbide module, and is used to isolate the high voltage and low voltage of the silicon carbide module. The anti-reverse circuit is used to isolate the drain high voltage and low voltage weak current circuit of the silicon carbide module Q1, and protect the short-circuit signal processing circuit from damage by reverse current.

[0071] As an optional implementation, in an embodiment of the invention, see Figure 3 As shown, the anti-reverse circuit includes: a second diode D2 and a third diode D3, the anode of the second diode D2 is connected to the second end of the second resistor R2 and the cathode of the fourth diode D4, the anode of the third diode D3 is connected to the cathode of the second diode D2, and the cathode of the third diode D3 is connected to the silicon carbide module, the second diode D2 and the third diode D3 have unidirectional conductivity, which can effectively prevent the current of the silicon carbide module Q1 from flowing in reverse, thereby protecting the short-circuit signal processing circuit.

[0072] An embodiment of the present invention also provides a short-circuit protection device for a silicon carbide module, comprising the aforementioned short-circuit protection circuit of the silicon carbide module, wherein the short-circuit protection circuit of the silicon carbide module is provided with a short-circuit signal acquisition circuit, a short-circuit signal processing circuit and an oscillation signal processing circuit, wherein the short-circuit signal processing circuit is arranged between the short-circuit signal acquisition circuit and the silicon carbide module, and the oscillation signal processing circuit is connected to the short-circuit signal acquisition circuit, the short-circuit signal processing circuit and the silicon carbide module, and is configured to: collect the oscillation voltage generated when the silicon carbide module is turned on, and output the processed oscillation voltage between the short-circuit signal processing circuit and the short-circuit signal acquisition circuit, so as to suppress the oscillation component in the short-circuit signal output by the short-circuit signal processing circuit to the short-circuit signal acquisition circuit.

[0073] The short-circuit protection device of the silicon carbide module of the embodiment of the present invention, the short-circuit protection circuit of the silicon carbide module first collects the oscillation voltage generated when the silicon carbide module is turned on through the oscillation signal processing circuit, and then adds a negative feedback to the short-circuit voltage collected by the short-circuit signal collection circuit through isolation, amplification and introduction of negative feedback, so as to reduce the amplitude of the short-circuit voltage during the high-frequency oscillation of the silicon carbide module, suppress the overshoot voltage generated by the high-frequency oscillation of the silicon carbide module, improve the accuracy of the short-circuit voltage of the silicon carbide module, and prevent the short-circuit protection of the silicon carbide module from being falsely triggered.

[0074] In the description of the present invention, it should be noted that the terms "upper", "lower", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0075] It should be noted that, in the present invention, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0076] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features of the present invention.

Claims

1. A short-circuit protection circuit for a silicon carbide module, characterized in that: include: Short circuit signal acquisition circuit; A short-circuit signal processing circuit, wherein the short-circuit signal processing circuit is arranged between the short-circuit signal acquisition circuit and the silicon carbide module; An oscillation signal processing circuit, the oscillation signal processing circuit is connected to the short-circuit signal acquisition circuit, the short-circuit signal processing circuit and the silicon carbide module, and is configured as follows: The oscillating voltage generated when the silicon carbide module is turned on is collected, and the oscillating voltage is processed and output between the short-circuit signal processing circuit and the short-circuit signal acquisition circuit to suppress the oscillating component in the short-circuit signal output by the short-circuit signal processing circuit to the short-circuit signal acquisition circuit.

2. The short-circuit protection circuit of the silicon carbide module according to claim 1, characterized in that: The oscillation signal processing circuit comprises: An oscillation signal acquisition circuit, wherein the oscillation signal acquisition circuit is connected to the short-circuit signal processing circuit and the silicon carbide module; An oscillation signal amplifying circuit, wherein the oscillation signal amplifying circuit is connected to the oscillation signal collecting circuit; An oscillation signal suppression circuit is connected to the oscillation signal amplification circuit and the short-circuit signal processing circuit.

3. The short-circuit protection circuit of the silicon carbide module according to claim 2, characterized in that: The oscillation signal acquisition circuit comprises: a fourth diode D4, wherein a cathode of the fourth diode D4 is connected to the short-circuit signal processing circuit and the silicon carbide module; a second capacitor C2, wherein a first end of the second capacitor C2 is connected to the anode of the fourth diode D4; A third resistor R3, a first end of the third resistor R3 is connected to the second end of the second capacitor C2, and a second end of the third resistor R3 is grounded.

4. The short-circuit protection circuit of the silicon carbide module according to claim 3, characterized in that: The oscillation signal amplifying circuit comprises: An operational amplifier U1, wherein a non-inverting terminal of the operational amplifier U1 is connected to a first terminal of the third resistor R3 and a second terminal of the second capacitor C2; a fourth resistor R4, wherein a first end of the fourth resistor R4 is connected to the inverting end of the operational amplifier U1, and a second end of the fourth resistor R4 is grounded; A fifth resistor R5, wherein a first end of the fifth resistor R5 is connected to a first end of the fourth resistor R4 and an inverting end of the operational amplifier U1, and a second end of the fifth resistor R5 is connected to an output end of the operational amplifier U1.

5. The short-circuit protection circuit of the silicon carbide module according to claim 4, characterized in that: The oscillation signal suppression circuit comprises: a sixth resistor R6, wherein a first end of the sixth resistor R6 is connected to the output end of the operational amplifier U1 and a second end of the fifth resistor R5, and a second end of the sixth resistor R6 is grounded; A first field effect transistor Q2, wherein a gate of the first field effect transistor Q2 is connected to a first end of the sixth resistor R6, and a source of the first field effect transistor Q2 is grounded; A third capacitor C3, a first end of the third capacitor C3 is connected to the drain of the first field effect transistor Q2, and a second end of the third capacitor C3 is grounded; A seventh resistor R7, wherein a first end of the seventh resistor R7 is connected to a first end of the third capacitor C3 and a drain of the field effect transistor Q2, and a second end of the seventh resistor R7 is connected to the short-circuit signal processing circuit.

6. The short-circuit protection circuit of the silicon carbide module according to claim 5, characterized in that: The short-circuit signal processing circuit comprises: A first resistor R1, wherein a first end of the first resistor R1 is connected to a power source; A first capacitor C1, wherein a first end of the first capacitor C1 is connected to a second end of the first resistor R1, and a second end of the first capacitor C1 is grounded; a first diode D1, wherein a cathode of the first diode D1 is connected to a first end of the first capacitor C1 and a second end of the seventh resistor R7, and an anode of the first diode D1 is grounded; A second resistor R2, wherein a first end of the second resistor R2 is connected to the cathode of the first diode D1 and a second end of the seventh resistor R7, and a second end of the second resistor R2 is connected to the silicon carbide module.

7. The short-circuit protection circuit of the silicon carbide module according to claim 6, characterized in that: The short-circuit signal acquisition circuit comprises: A driving chip, the driving chip is connected to the second end of the first resistor R1 and the first end of the first capacitor C1, and is used to compare the collected short-circuit voltage of the silicon carbide module with the short-circuit threshold voltage and act according to the comparison result.

8. The short-circuit protection circuit of the silicon carbide module according to claim 7, characterized in that: Also includes: An anti-reverse circuit is provided between the short-circuit signal processing circuit and the silicon carbide module, and is used to isolate the high voltage and the low voltage of the silicon carbide module.

9. The short-circuit protection circuit of the silicon carbide module according to claim 8, characterized in that: The anti-reverse circuit comprises: a second diode D2, wherein an anode of the second diode D2 is connected to a second end of the second resistor R2 and a cathode of the fourth diode D4; A third diode D3, wherein an anode of the third diode D3 is connected to a cathode of the second diode D2, and a cathode of the third diode D3 is connected to the silicon carbide module.

10. A short-circuit protection device for a silicon carbide module, characterized in that: A short-circuit protection circuit comprising a silicon carbide module as claimed in any one of claims 1 to 9.

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