An intelligent power module integrated with short circuit protection of SiC power device

Abstract

The application relates to the field of power electronics, in particular to an intelligent power module integrated with SiC power device short-circuit protection, which comprises a plurality of SiC power devices; further comprises a driving unit, a short-circuit voltage adaptation unit, an OR gate U4 and a plurality of short-circuit protection action units; the short-circuit protection action unit is used for receiving a driving signal generated by the driving unit and transmitting the driving signal to the SiC power device; and is further used for turning off the SiC power device when a short-circuit trigger signal is received; the short-circuit voltage adaptation unit is used for monitoring the on-voltage of the plurality of SiC power devices in real time; when the on-voltage of any one is greater than the short-circuit threshold voltage for a duration greater than the blanking time, a short-circuit trigger signal is generated and transmitted to the short-circuit protection action unit; the size of the on-voltage and the size of the blanking time are linearly inversely related; thus, all the SiC power devices inside are protected from short circuit, the blanking time of the short-circuit protection is more suitable for different bus voltages, and the short-circuit protection precision and efficiency are higher.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to an intelligent power module integrated with short-circuit protection of a SiC power device. Background Art

[0002] An intelligent power module (IPM) is a power drive product that combines power electronics and integrated circuit technology. With the rapid development of industry, the application scenarios of intelligent power modules have increased, and energy efficiency standards have been improved. Intelligent power modules that use SiC power devices (such as SiC-MOSFETs) as switching devices in both the upper and lower bridge arms have higher voltage resistance, lower switching losses, and faster switching speeds. They can significantly improve the efficiency, power density, and reliability of power electronic devices, and have broader application prospects in high-temperature, high-frequency, high-voltage, and high-power applications. This makes SiC power devices an indispensable key component of intelligent power modules. However, in actual applications, SiC power devices inevitably have to operate under working conditions such as overload and desaturation, which may cause short circuits in the SiC power devices. Due to the characteristics and application environment of SiC power devices, they are more sensitive to various types of short-circuit faults and are very prone to false triggering. This requires them to have short-circuit fault protection capabilities to protect themselves and the integrated circuits used, and to be able to implement protection measures when short-circuit faults such as overload and desaturation occur. Therefore, the performance of the short-circuit protection circuit of SiC power devices is the key to determining whether short-circuit protection can be implemented quickly and accurately.

[0003] Existing intelligent power modules do not have short-circuit detection and protection circuits for switching devices such as IGBTs and SiC-MOSFETs. The existing solution is to detect switching devices such as IGBTs and SiC-MOSFETs in the intelligent power module through peripheral circuits, and then transmit them together with other short-circuit detection signals in the peripheral circuits to the ITRIP terminal of the power module, and then transmit them to the internal chip to perform short-circuit fault detection and short-circuit protection actions for the overall solution.

[0004] Because the data is sampled by peripheral circuits and transmitted to the intelligent power module for short-circuit detection, the short-circuit protection action time is relatively long (i.e., sufficient blanking time is reserved). Although this avoids false triggering of the SiC power device, it causes the SiC power device to withstand the short-circuit current for a longer time. In addition, since the characteristic of SiC power devices is that the higher the bus voltage, the shorter the short-circuit withstand time, the short-circuit protection action time must be as short as possible while avoiding false action. Therefore, for intelligent power modules using SiC power devices as switching devices, a short-circuit protection circuit that can automatically adapt the blanking time according to different bus voltages is even more necessary. This circuit should be integrated into the intelligent power module to achieve fast and accurate protection against short-circuit faults (such as overload, desaturation, etc.). Summary of the Invention

[0005] In response to the above-mentioned defects, the purpose of the present invention is to propose an intelligent power module with integrated SiC power device short-circuit protection, which provides short-circuit protection for all internal SiC power devices. The blanking time of the short-circuit protection is more adaptable to different bus voltages, and the short-circuit protection accuracy and efficiency are higher.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] An intelligent power module with integrated short-circuit protection for SiC power devices, comprising a plurality of SiC power devices; a driving unit, a short-circuit voltage adaptation unit, an OR gate U4, and a plurality of short-circuit protection action units; the input terminals of the plurality of short-circuit protection action units are electrically connected to the plurality of driving terminals of the driving unit in a one-to-one correspondence, the output terminals of the short-circuit protection action units are electrically connected to the driving terminals of the SiC power devices, the driving terminals of the plurality of SiC power devices are electrically connected to the plurality of input terminals of the OR gate U4, the output terminals of the OR gate U4 are electrically connected to the feedback terminals of the short-circuit voltage adaptation unit, the conduction voltage terminals of the plurality of SiC power devices are electrically connected to the plurality of input terminals of the short-circuit voltage adaptation unit, and the trigger terminals of the plurality of short-circuit protection action units are electrically connected to the output terminals of the short-circuit voltage adaptation unit;

[0008] The short-circuit protection action unit is used to receive the driving signal generated by the driving unit and transmit it to the SiC power device; and is also used to shut down the SiC power device when a short-circuit trigger signal is received;

[0009] The short-circuit voltage adaptation unit is used to monitor the on-state voltages of the plurality of SiC power devices in real time; when the on-state voltage of any one of the SiC power devices is greater than the short-circuit threshold voltage for a duration greater than the blanking time, the short-circuit trigger signal is generated and transmitted to the short-circuit protection action unit; the magnitude of the on-state voltage and the magnitude of the blanking time are in a linear inverse proportional relationship.

[0010] Furthermore, the short-circuit voltage adaptation unit includes an isolation circuit, a trigger-type judgment circuit, and a plurality of trigger-type acquisition circuits; the input end of the trigger-type acquisition circuit is used as the input end of the short-circuit voltage adaptation unit, the feedback end of the trigger-type judgment circuit is used as the feedback end of the short-circuit voltage adaptation unit, and the output end of the trigger-type judgment circuit is used as the output end of the short-circuit voltage adaptation unit;

[0011] The output ends of the multiple trigger-type acquisition circuits are electrically connected to the multiple input ends of the isolation circuit respectively, and the output end of the isolation circuit is electrically connected to the input end of the trigger-type judgment circuit;

[0012] The short-circuit threshold voltage includes a first threshold voltage and a second threshold voltage;

[0013] The trigger acquisition circuit is used to monitor the conduction voltage in real time; when the conduction voltage is greater than the first threshold voltage, the conduction voltage is transmitted to the trigger judgment circuit via the isolation circuit;

[0014] The trigger judgment circuit is configured to, when receiving the conduction voltage, determine that a value decreases, and the magnitude of the conduction voltage is linearly proportional to the rate of decrease of the judgment value; if the judgment value decreases to less than the second threshold voltage, the short-circuit trigger signal is generated; and the time for the trigger judgment circuit to decrease to less than the second threshold voltage is the blanking time;

[0015] The isolation circuit is used to electrically isolate the trigger-type acquisition circuit and the trigger-type judgment circuit.

[0016] Furthermore, the trigger judgment circuit includes a NOT gate U1, a NOT gate U3, a MOS tube M1, a resistor R6, a resistor R7, a resistor R8, a capacitor C1, a comparator A2 and a Schmitt trigger U2; the input end of the NOT gate U1 is used as the feedback end of the trigger judgment circuit, one end of the resistor R6 is used as the input end of the trigger judgment circuit, and the output end of the NOT gate U3 is used as the output end of the trigger judgment circuit;

[0017] The other end of the resistor R6, one end of the capacitor C1, and the source of the MOS transistor M1 are all electrically connected to the negative input end of the comparator A2, the gate of the MOS transistor M1 is electrically connected to the output end of the NOT gate U1, the drain of the MOS transistor M1 is electrically connected to one end of the resistor R8, the other end of the resistor R8, the other end of the capacitor C1, and the input end of the Schmitt trigger U2 are all electrically connected to the output end of the comparator A2, the positive input end of the comparator A2 is electrically connected to one end of the resistor R7, the other end of the resistor R7 is connected to the VSS power supply, and the output end of the Schmitt trigger U2 is electrically connected to the input end of the NOT gate U3.

[0018] Furthermore, the short-circuit protection action unit is an AND gate U5; the first input end of the AND gate U5 is used as the trigger end of the short-circuit protection action unit, the second input end of the AND gate U5 is used as the input end of the short-circuit protection action unit, and the output end of the AND gate U5 is used as the output end of the short-circuit protection action unit.

[0019] Furthermore, the trigger acquisition circuit includes a diode D1, a diode D2, a resistor R2, and a resistor element R1; the cathode of the diode D1 serves as the positive electrode of the input end of the trigger acquisition circuit, one end of the resistor R2 serves as the negative electrode of the input end of the trigger acquisition circuit, and the anode of the diode D2 serves as the output end of the trigger acquisition circuit;

[0020] An anode of the diode D1 is electrically connected to one end of the resistor R1 , and the other end of the resistor R1 and the other end of the resistor R2 are both electrically connected to the cathode of the diode D2 .

[0021] Furthermore, the isolation circuit includes a resistor R4, a resistor R5 and a comparator A1; one end of the resistor R4 is used as an input end of the isolation circuit, and the output end of the comparator A1 is used as an output end of the isolation circuit;

[0022] The other end of the resistor R4 is electrically connected to the positive input end of the comparator A1, one end of the resistor R5 is electrically connected to the negative input end of the comparator A1, and the other end of the resistor R5 is electrically connected to the output end of the comparator A1.

[0023] Furthermore, the trigger judgment circuit is used to, when receiving the conduction voltage, the judgment value rises, and the magnitude of the conduction voltage is linearly proportional to the rising speed of the judgment value; if the judgment value rises to be greater than the second threshold voltage, the short-circuit trigger signal is generated; the time for the trigger judgment circuit to rise to be greater than the second threshold voltage is the blanking time.

[0024] Furthermore, the resistor R1 is a single large resistor whose resistance is much greater than that of the resistor R2, one end of the large resistor serves as one end of the resistor R1, and the other end of the large resistor serves as the other end of the resistor R1;

[0025] Alternatively, the resistor element R1 is a series resistor circuit with a total resistance much greater than that of the resistor R2, and the series resistor circuit is composed of multiple small resistors in series, the other end of the previous small resistor and one end of the next small resistor are electrically connected, one end of the first small resistor is used as one end of the resistor element R1, and the other end of the last small resistor is used as the other end of the resistor element R1.

[0026] The technical solution provided by the application can include the following beneficial effects: the short-circuit protection mechanism composed of the short-circuit voltage adaptation unit or the gate U4 and the plurality of short-circuit protection action units is integrated in the intelligent power module, all SiC power devices inside are detected in real time, and the blanking time that can adapt to different bus voltages is set to perform fast and accurate short-circuit protection action, which is more suitable for the integrated environment of the plurality of SiC power devices and improves the short-circuit protection efficiency of the intelligent power module.

[0027] Specifically, taking Figure 3 as an example, the SiC power devices in the intelligent power module are mainly used for the inverter unit, Figure 3 is the electrical connection mode of two SiC power devices on a bridge arm of the inverter unit in the intelligent power module; taking the SiC-MOSFET as an example, the gate of the SiC-MOSFET is used as the driving end of the SiC power device, the drain of the SiC-MOSFET is used as the positive pole of the conduction voltage end of the SiC power device, and the source of the SiC-MOSFET is used as the negative pole of the conduction voltage end of the SiC power device, so that the SiC-MOSFET normally works under the driving of the driving unit; when the SiC-MOSFET has an overload, desaturation or other short-circuit faults, the voltage between the drain and the source of the SiC-MOSFET (i.e., the conduction voltage) will rise to the voltage of the bus to which the SiC-MOSFET is connected, and the higher the bus voltage, the shorter the tolerance time of the SiC-MOSFET; therefore, the short-circuit voltage adaptation unit monitors the conduction voltage of the SiC power device in real time, generates a short-circuit trigger signal when the conduction voltage is greater than the short-circuit threshold voltage and the duration is greater than the blanking time, and transmits the short-circuit trigger signal to the short-circuit protection action unit, so as to turn off the SiC power device by the short-circuit protection action unit to achieve protection and prevent false triggering of the short-circuit protection; and since the size of the conduction voltage and the size of the blanking time are in a linear inverse relationship, compared with the RC charging and discharging circuit that makes the size of the conduction voltage (short-circuit voltage) and the size of the blanking time in a parabolic inverse relationship (i.e., facing different short-circuit voltages, the blanking time changes very little), facing different conduction voltages, the blanking time changes linearly, so that the blanking time is more suitable for different bus voltages; finally, the short-circuit protection is more accurate and more in line with the performance requirements of the SiC power device. At the same time, the or gate U4 feeds back the short-circuit protection action of the short-circuit protection action unit in real time, is used for maintaining the short-circuit protection action of the short-circuit voltage adaptation unit and the short-circuit protection action unit in the case that the short-circuit fault has not disappeared, and keeps the SiC power device off, that is, the or gate U4 outputs a high level when detecting the short-circuit action of any SiC power device. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a circuit schematic diagram of an intelligent power module integrated with SiC power device short-circuit protection according to one embodiment of the application.

[0029] Figure 2 Yes Figure 1 The schematic diagram of the local circuit at point A of an intelligent power module with integrated SiC power device short-circuit protection is shown.

[0030] Figure 3 Yes Figure 1 The schematic diagram of the local circuit at point B of an intelligent power module with integrated SiC power device short-circuit protection is shown.

[0031] Figure 4 Yes Figure 2 The Vc-t waveform diagram of the trigger judgment circuit is shown.

[0032] Among them: drive unit 1, short-circuit voltage adaptation unit 2, OR gate U4, short-circuit protection action unit 3, SiC power device 4, isolation circuit 22, trigger judgment circuit 23, trigger acquisition circuit 21, NOT gate U1, NOT gate U3, MOS tube M1, resistor R6, resistor R7, resistor R8, capacitor C1, comparator A2, Schmitt trigger U2, AND gate U5, diode D1, diode D2, resistor R2, resistor element R1, resistor R4, resistor R5, comparator A1. DETAILED DESCRIPTION

[0033] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0034] In the description of the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the described features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically specified.

[0035] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections or indirect connections through an intermediate medium; they may refer to internal communication between two components or an interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0036] The following combination Figures 1 to 4 , describing an intelligent power module with integrated SiC power device short-circuit protection according to an embodiment of the present invention.

[0037] An intelligent power module with integrated short-circuit protection for SiC power devices, comprising a plurality of SiC power devices 4; a drive unit 1, a short-circuit voltage adaptation unit 2, an OR gate U4, and a plurality of short-circuit protection action units 3; the input terminals of the plurality of short-circuit protection action units 3 are electrically connected to the plurality of drive terminals of the drive unit 1 in a one-to-one correspondence, the output terminals of the short-circuit protection action units 3 are electrically connected to the drive terminals of the SiC power devices 4, the drive terminals of the plurality of SiC power devices 4 are respectively electrically connected to the plurality of input terminals of the OR gate U4, the output terminal of the OR gate U4 is electrically connected to the feedback terminal of the short-circuit voltage adaptation unit 2, the conduction voltage terminals of the plurality of SiC power devices 4 are respectively electrically connected to the plurality of input terminals of the short-circuit voltage adaptation unit 2, and the trigger terminals of the plurality of short-circuit protection action units 3 are all electrically connected to the output terminal of the short-circuit voltage adaptation unit 2;

[0038] The short-circuit protection action unit 3 is used to receive the driving signal generated by the driving unit 1 and transmit it to the SiC power device 4; it is also used to turn off the SiC power device 4 when a short-circuit trigger signal is received;

[0039] The short-circuit voltage adaptation unit 2 is used to monitor the on-state voltages of multiple SiC power devices 4 in real time; when the duration of any on-state voltage exceeding the short-circuit threshold voltage is greater than the blanking time, a short-circuit trigger signal is generated and transmitted to the short-circuit protection action unit 3; the magnitude of the on-state voltage and the magnitude of the blanking time are in a linear inverse proportional relationship.

[0040] The present invention proposes a preferred embodiment of an intelligent power module integrated with short-circuit protection of SiC power devices, such as Figures 1 to 3 As shown, the short-circuit protection mechanism consisting of a short-circuit voltage adaptation unit 2, an OR gate U4, and multiple short-circuit protection action units 3 is integrated into the intelligent power module. It detects all internal SiC power devices 4 in real time and sets a blanking time that can adapt to different bus voltages to perform fast and accurate short-circuit protection actions. It is more suitable for the integrated environment of multiple SiC power devices 4 and improves the short-circuit protection efficiency of the intelligent power module.

[0041] Specifically, Figure 3 For example, the SiC power device 4 in the intelligent power module is mainly used in the inverter unit. Figure 3It is the electrical connection method of two SiC power devices 4 on a group of bridge arms of the inverter unit in the intelligent power module; the SiC power device 4 takes SiC-MOSFET as an example, the gate of the SiC-MOSFET is used as the driving end of the SiC power device 4, the drain of the SiC-MOSFET is used as the positive electrode of the conduction voltage end of the SiC power device 4, and the source of the SiC-MOSFET is used as the negative electrode of the conduction voltage end of the SiC power device 4, then the SiC-MOSFET works normally under the drive of the driving unit 1; when the SiC-MOSFET has a short-circuit fault such as overload or desaturation, it will cause the voltage between the drain and source of the SiC-MOSFET (i.e., the conduction voltage) to rise to the voltage of the bus to which it is connected, then the higher the bus voltage, the longer the withstand time of the SiC-MOSFET. short; therefore, the on-state voltage of the SiC power device 4 is monitored in real time through the short-circuit voltage adaptation unit 2. When the on-state voltage is greater than the short-circuit threshold voltage for a duration greater than the blanking time, a short-circuit trigger signal is generated and transmitted to the short-circuit protection action unit 3, and the short-circuit protection action unit 3 turns off the SiC power device 4 to achieve protection, thereby preventing false triggering of the short-circuit protection; and since the magnitude of the on-state voltage and the magnitude of the blanking time are in a linear inverse proportional relationship, compared with the RC charge and discharge circuit that makes the magnitude of the on-state voltage (short-circuit voltage) and the magnitude of the blanking time in a parabolic inverse proportional relationship (that is, the blanking time changes very little in the face of different short-circuit voltages), the blanking time changes linearly in the face of different on-state voltages, thereby making the blanking time more adaptable to different bus voltages; ultimately, the short-circuit protection is more accurate and more in line with the performance requirements of the SiC power device 4. At the same time, the OR gate U4 provides real-time feedback on the short-circuit protection action status of the short-circuit protection action unit 3, and is used to maintain the short-circuit protection action of the short-circuit voltage adaptation unit 2 and the short-circuit protection action unit 3 when the short-circuit fault has not disappeared, and keep the SiC power device 4 turned off, that is, the OR gate U4 outputs a high level when it detects that any SiC power device 4 is in short-circuit action.

[0042] It should be noted that, since a short circuit fault in any SiC power device 4 integrated inside the intelligent power module will cause the entire inverter unit to fail, all SiC power devices 4 will be shut down if a short circuit fault occurs in any SiC power device 4 .

[0043] Furthermore, the short-circuit voltage adaptation unit 2 includes an isolation circuit 22, a trigger-type judgment circuit 23, and a plurality of trigger-type acquisition circuits 21; the input end of the trigger-type acquisition circuit 21 is used as the input end of the short-circuit voltage adaptation unit 2, the feedback end of the trigger-type judgment circuit 23 is used as the feedback end of the short-circuit voltage adaptation unit 2, and the output end of the trigger-type judgment circuit 23 is used as the output end of the short-circuit voltage adaptation unit 2;

[0044] The output terminals of the multiple trigger-type acquisition circuits 21 are electrically connected to the multiple input terminals of the isolation circuit 22 respectively, and the output terminal of the isolation circuit 22 is electrically connected to the input terminal of the trigger-type judgment circuit 23;

[0045] The short-circuit threshold voltage includes a first threshold voltage and a second threshold voltage;

[0046] The trigger acquisition circuit 21 is used to monitor the conduction voltage in real time; when the conduction voltage is greater than the first threshold voltage, the conduction voltage is transmitted to the trigger judgment circuit 23 via the isolation circuit 22;

[0047] The trigger judgment circuit 23 is configured to determine a decrease in the judgment value when receiving the conduction voltage, and the magnitude of the conduction voltage is linearly proportional to the rate of decrease of the judgment value; if the judgment value decreases to less than a second threshold voltage, a short-circuit trigger signal is generated; the time during which the trigger judgment circuit 23 decreases to less than the second threshold voltage is the blanking time;

[0048] The isolation circuit 22 is used to electrically isolate the trigger-type acquisition circuit 21 and the trigger-type judgment circuit 23 .

[0049] In this embodiment, in order to realize the generation of blanking time according to the linear inverse relationship between the magnitude of the conduction voltage, the short-circuit threshold voltage is set as two thresholds, the first threshold voltage and the second threshold voltage, to limit the blanking time; wherein the first threshold voltage is the trigger value used by the trigger acquisition circuit 21 to determine whether a short-circuit fault occurs. The trigger acquisition circuit 21 monitors the conduction voltage in real time. When the conduction voltage is greater than the first threshold voltage, it means that a short circuit occurs but it cannot be determined whether it is a permanent fault. Therefore, the conduction voltage is transmitted to the trigger judgment circuit 23 at this time; the second threshold voltage is the trigger judgment circuit 23 used to determine whether it is a short circuit. The trigger value of a permanent short-circuit fault is that after the trigger-type judgment circuit 23 receives the conduction voltage, the internal judgment value decreases accordingly. The decreasing speed of the judgment value is linearly proportional to the magnitude of the conduction voltage. If the judgment value decreases to less than the second threshold voltage, a short-circuit trigger signal is generated (indicating a permanent short-circuit fault). It can be seen that the time it takes for the trigger-type judgment circuit 23 to drop below the second threshold voltage is the blanking time. From this, the relationship can be derived: decreasing speed = second threshold voltage / blanking time. It can be deduced that the magnitude of the conduction voltage (short-circuit voltage) and the magnitude of the blanking time are linearly inversely proportional, which meets the requirements.

[0050] More importantly, the isolation circuit 22 is arranged between the trigger acquisition circuit 21 and the trigger judgment circuit 23 for electrical isolation, which can effectively isolate the drive unit side and the short-circuit protection unit side, avoid mutual interference between the signals on both sides, and make the normal drive work and the short-circuit protection work run separately, thereby improving the stability of the short-circuit protection circuit and the integrated circuit.

[0051] Furthermore, the trigger judgment circuit 23 includes a NOT gate U1, a NOT gate U3, a MOS transistor M1, a resistor R6, a resistor R7, a resistor R8, a capacitor C1, a comparator A2, and a Schmitt trigger U2; the input end of the NOT gate U1 serves as a feedback end of the trigger judgment circuit 23, one end of the resistor R6 serves as an input end of the trigger judgment circuit 23, and the output end of the NOT gate U3 serves as an output end of the trigger judgment circuit 23;

[0052] The other end of the resistor R6, one end of the capacitor C1, and the source of the MOS transistor M1 are all electrically connected to the negative input terminal of the comparator A2, the gate of the MOS transistor M1 is electrically connected to the output terminal of the NOT gate U1, the drain of the MOS transistor M1 is electrically connected to one end of the resistor R8, the other end of the resistor R8, the other end of the capacitor C1, and the input terminal of the Schmitt trigger U2 are all electrically connected to the output terminal of the comparator A2, the positive input terminal of the comparator A2 is electrically connected to one end of the resistor R7, the other end of the resistor R7 is connected to the VSS power supply, and the output terminal of the Schmitt trigger U2 is electrically connected to the input terminal of the NOT gate U3.

[0053] In this embodiment, the second threshold voltage of the trigger judgment circuit 23 is the trigger value of the Schmitt trigger U2, and its function is realized in conjunction with the active integration circuit composed of the NOT gate U1, MOS transistor M1, resistor R6, resistor R7, resistor R8, capacitor C1 and comparator A2. Specifically, when a short circuit fault occurs, such as Figure 4 As shown, the active integration circuit will continue to receive the conduction voltage (the negative input terminal of the comparator A2 is at a high level), and the output voltage Vc (i.e., the judgment value) of the active integration circuit will continue to decrease with the duration of receiving the conduction voltage until it drops to the second threshold voltage to trigger the Schmitt trigger U2 to output a high level (short-circuit trigger signal). Due to the characteristics of the active integration circuit, the decreasing speed of the output voltage Vc will be linearly proportional to the magnitude of the conduction voltage, as shown in FIG. Figure 4 As can be seen from the multiple curves in Figure 1, each curve represents a bus voltage connected to SiC power device 4, with a blanking time of t1 and a slope representing the rate of decrease of output voltage Vc. After SiC power device 4 is turned off, MOS transistor M1 is used to provide feedback on the shutdown status of SiC power device 4, turning MOS transistor M1 on. Resistor R8 provides a discharge circuit for capacitor C1, preparing for the next short-circuit detection.

[0054] Furthermore, the short-circuit protection action unit 3 is an AND gate U5; the first input end of the AND gate U5 is used as the trigger end of the short-circuit protection action unit 3, the second input end of the AND gate U5 is used as the input end of the short-circuit protection action unit 3, and the output end of the AND gate U5 is used as the output end of the short-circuit protection action unit 3.

[0055] In this embodiment, the short-circuit protection action unit 3 needs to cooperate with the circuit logic of the trigger judgment circuit 23 to realize the control of the SiC power device 4 to be turned on and off according to the driving signal during normal operation and to keep it turned off when a short-circuit fault occurs. Therefore, the short-circuit protection action unit 3 is a logic circuit composed of an AND gate U5; when a short-circuit fault occurs, the Schmitt trigger U2 outputs a high level (short-circuit trigger signal), and after the NOT gate U3 is inverted, at this time, regardless of the driving signal ( Figure 3 The AND gate U5 outputs a low level to turn off the SiC power device 4, regardless of whether the HO1 or LO1 input is high or low. During normal operation, the Schmitt trigger U2 constantly outputs a low level. After the NOT gate U3 is inverted, the output of the AND gate U5 remains consistent with the drive signal, regardless of whether the drive signal is high or low, and the SiC power device 4 is driven normally.

[0056] Furthermore, the trigger acquisition circuit 21 includes a diode D1, a diode D2, a resistor R2, and a resistor element R1; the cathode of the diode D1 serves as the positive electrode of the input end of the trigger acquisition circuit 21, one end of the resistor R2 serves as the negative electrode of the input end of the trigger acquisition circuit 21, and the anode of the diode D2 serves as the output end of the trigger acquisition circuit 21;

[0057] An anode of the diode D1 is electrically connected to one end of the resistor R1 , and the other end of the resistor R1 and the other end of the resistor R2 are both electrically connected to the cathode of the diode D2 .

[0058] In this embodiment, the first threshold voltage of the trigger acquisition circuit 21 is the reverse bias voltage threshold of the diode D1. Only when the short-circuit fault conduction voltage is too large can the diode D1 be reverse biased, and the conduction voltage is collected and transmitted to the isolation circuit 22 and the subsequent trigger judgment circuit 23 through the voltage divider circuit composed of the resistor R2 and the resistor element R1. The diode D2 is used to isolate the transmission between the trigger acquisition circuits 21 when multiple trigger acquisition circuits 21 simultaneously feed back signals to the isolation circuit 22.

[0059] Furthermore, the isolation circuit 22 includes a resistor R4, a resistor R5 and a comparator A1; one end of the resistor R4 is used as an input end of the isolation circuit 22, and the output end of the comparator A1 is used as an output end of the isolation circuit 22;

[0060] The other end of the resistor R4 is electrically connected to the positive input terminal of the comparator A1 , one end of the resistor R5 is electrically connected to the negative input terminal of the comparator A1 , and the other end of the resistor R5 is electrically connected to the output terminal of the comparator A1 .

[0061] In the embodiment, the isolation circuit 22 is a voltage follower composed of the resistor R4, the resistor R5 and the comparator A1; since the impedance of the voltage dividing resistor of the trigger type acquisition circuit 21 is far greater than the impedance of the active integration circuit of the trigger type judgment circuit 23, the voltage follower can transmit the on voltage to the active integration circuit for integration when short circuit occurs, and the voltage follower can also play the role of isolation and buffering, and play the function of electrical isolation.

[0062] Further, the trigger type judgment circuit 23 is used for judging the value rising when the on voltage is received, the size of the on voltage and the rising speed of the judgment value are in linear proportional relationship; if the judgment value rises to be greater than the second threshold voltage, a short circuit trigger signal is generated; the time of the trigger type judgment circuit 23 rising to be greater than the second threshold voltage is the blanking time.

[0063] In the embodiment, since the trigger mode of the Schmitt trigger U2 can also be positive voltage trigger, the function of the trigger type judgment circuit 23 can also be realized by the rising relationship of the judgment value.

[0064] Further, the resistor R1 is a single large resistor with a resistance value far greater than that of the resistor R2, one end of the large resistor is used as one end of the resistor R1, and the other end of the large resistor is used as the other end of the resistor R1.

[0065] Or the resistor R1 is a series resistor circuit with a total resistance value far greater than that of the resistor R2, the series resistor circuit is composed of a plurality of small resistors connected in series, the other end of a first small resistor and one end of a second small resistor are electrically connected, one end of the first small resistor is used as one end of the resistor R1, and the other end of the last small resistor is used as the other end of the resistor R1.

[0066] In the embodiment, the resistor R1 with a resistance value far greater than that of the resistor R2 is used to compose the voltage dividing circuit, which can improve the acquisition accuracy.

[0067] Other configurations and operations of the intelligent power module integrated with the SiC power device short circuit protection according to the embodiment of the application are known to those skilled in the art, and will not be described in detail here.

[0068] In the description of the specification, the description referring to the terms "embodiment", "example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0069] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. An intelligent power module with integrated SiC power device short-circuit protection, comprising multiple SiC power devices; characterized in that: It also includes a driving unit, a short-circuit voltage adaptation unit, an OR gate U4 and a plurality of short-circuit protection action units; the input terminals of the plurality of short-circuit protection action units are electrically connected to the plurality of driving terminals of the driving unit in a one-to-one correspondence, the output terminal of the short-circuit protection action unit is electrically connected to the driving terminal of the SiC power device, the driving terminals of the plurality of SiC power devices are electrically connected to the plurality of input terminals of the OR gate U4, the output terminal of the OR gate U4 is electrically connected to the feedback terminal of the short-circuit voltage adaptation unit, the conduction voltage terminals of the plurality of SiC power devices are electrically connected to the plurality of input terminals of the short-circuit voltage adaptation unit, and the trigger terminals of the plurality of short-circuit protection action units are electrically connected to the output terminal of the short-circuit voltage adaptation unit; The short-circuit protection action unit is used to receive the driving signal generated by the driving unit and transmit it to the SiC power device; and is also used to shut down the SiC power device when a short-circuit trigger signal is received; The short-circuit voltage adaptation unit is used to monitor the on-state voltages of the plurality of SiC power devices in real time; when the on-state voltage of any one of the SiC power devices is greater than the short-circuit threshold voltage for a duration greater than the blanking time, the short-circuit trigger signal is generated and transmitted to the short-circuit protection action unit; the magnitude of the on-state voltage and the magnitude of the blanking time are in a linear inverse proportional relationship; The short-circuit voltage adaptation unit includes an isolation circuit, a trigger-type judgment circuit, and a plurality of trigger-type acquisition circuits; the input end of the trigger-type acquisition circuit serves as the input end of the short-circuit voltage adaptation unit, the feedback end of the trigger-type judgment circuit serves as the feedback end of the short-circuit voltage adaptation unit, and the output end of the trigger-type judgment circuit serves as the output end of the short-circuit voltage adaptation unit; The output ends of the multiple trigger-type acquisition circuits are electrically connected to the multiple input ends of the isolation circuit respectively, and the output end of the isolation circuit is electrically connected to the input end of the trigger-type judgment circuit; The short-circuit threshold voltage includes a first threshold voltage and a second threshold voltage; The trigger acquisition circuit is used to monitor the conduction voltage in real time; when the conduction voltage is greater than the first threshold voltage, the conduction voltage is transmitted to the trigger judgment circuit via the isolation circuit; The trigger judgment circuit is configured to, when receiving the conduction voltage, determine that a value decreases, and the magnitude of the conduction voltage is linearly proportional to the rate of decrease of the judgment value; if the judgment value decreases to less than the second threshold voltage, the short-circuit trigger signal is generated; The time it takes for the trigger judgment circuit to drop below the second threshold voltage is the blanking time; The isolation circuit is used to electrically isolate the trigger-type acquisition circuit and the trigger-type judgment circuit.

2. The intelligent power module with integrated SiC power device short-circuit protection according to claim 1, characterized in that: The trigger judgment circuit includes a NOT gate U1, a NOT gate U3, a MOS tube M1, a resistor R6, a resistor R7, a resistor R8, a capacitor C1, a comparator A2 and a Schmitt trigger U2; the input end of the NOT gate U1 is used as the feedback end of the trigger judgment circuit, one end of the resistor R6 is used as the input end of the trigger judgment circuit, and the output end of the NOT gate U3 is used as the output end of the trigger judgment circuit; The other end of the resistor R6, one end of the capacitor C1, and the source of the MOS transistor M1 are all electrically connected to the negative input end of the comparator A2, the gate of the MOS transistor M1 is electrically connected to the output end of the NOT gate U1, the drain of the MOS transistor M1 is electrically connected to one end of the resistor R8, the other end of the resistor R8, the other end of the capacitor C1, and the input end of the Schmitt trigger U2 are all electrically connected to the output end of the comparator A2, the positive input end of the comparator A2 is electrically connected to one end of the resistor R7, the other end of the resistor R7 is connected to the VSS power supply, and the output end of the Schmitt trigger U2 is electrically connected to the input end of the NOT gate U3.

3. The intelligent power module with integrated SiC power device short-circuit protection according to claim 1, characterized in that: The short-circuit protection action unit is an AND gate U5; the first input end of the AND gate U5 is used as the trigger end of the short-circuit protection action unit, the second input end of the AND gate U5 is used as the input end of the short-circuit protection action unit, and the output end of the AND gate U5 is used as the output end of the short-circuit protection action unit.

4. The intelligent power module with integrated SiC power device short-circuit protection according to claim 1, characterized in that: The trigger acquisition circuit includes a diode D1, a diode D2, a resistor R2, and a resistor R1; the cathode of the diode D1 serves as the positive electrode of the input end of the trigger acquisition circuit, one end of the resistor R2 serves as the negative electrode of the input end of the trigger acquisition circuit, and the anode of the diode D2 serves as the output end of the trigger acquisition circuit; An anode of the diode D1 is electrically connected to one end of the resistor R1 , and the other end of the resistor R1 and the other end of the resistor R2 are both electrically connected to the cathode of the diode D2 .

5. The intelligent power module with integrated SiC power device short-circuit protection according to claim 1, characterized in that: The isolation circuit includes a resistor R4, a resistor R5 and a comparator A1; one end of the resistor R4 is used as an input end of the isolation circuit, and the output end of the comparator A1 is used as an output end of the isolation circuit; The other end of the resistor R4 is electrically connected to the positive input end of the comparator A1, one end of the resistor R5 is electrically connected to the negative input end of the comparator A1, and the other end of the resistor R5 is electrically connected to the output end of the comparator A1.

6. The intelligent power module with integrated SiC power device short-circuit protection according to claim 1, characterized in that: Alternatively, the trigger judgment circuit is used to increase the judgment value when receiving the conduction voltage, and the magnitude of the conduction voltage is linearly proportional to the rising speed of the judgment value; if the judgment value rises to be greater than the second threshold voltage, the short-circuit trigger signal is generated; the time when the trigger judgment circuit rises to be greater than the second threshold voltage is the blanking time.

7. The intelligent power module with integrated SiC power device short-circuit protection according to claim 4, characterized in that: The resistor R1 is a single large resistor with a resistance much greater than that of the resistor R2. One end of the large resistor serves as one end of the resistor R1, and the other end of the large resistor serves as the other end of the resistor R1. Alternatively, the resistor element R1 is a series resistor circuit with a total resistance much greater than that of the resistor R2, and the series resistor circuit is composed of multiple small resistors in series, the other end of the previous small resistor and one end of the next small resistor are electrically connected, one end of the first small resistor is used as one end of the resistor element R1, and the other end of the last small resistor is used as the other end of the resistor element R1.

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