Intelligent power module integrated with SiC power device short circuit protection

Abstract

The invention relates to the technical 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, the circuit 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 the driving signal generated by the driving unit and transmitting the driving signal to the SiC power device; the switching module is also used for switching off the SiC power device when receiving the short-circuit trigger signal; the short-circuit voltage adaptation unit is used for monitoring the break-over voltage of the plurality of SiC power devices in real time; when the duration that any break-over voltage is greater than the short-circuit threshold voltage is greater than blanking time, a short-circuit trigger signal is generated and transmitted to the short-circuit protection action unit; the magnitude of the conduction voltage and the magnitude of the blanking time are linearly inversely proportional; therefore, all internal SiC power devices are subjected to short-circuit protection, the blanking time of the short-circuit protection is more adaptive to 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] Intelligent power module, or IPM (Intelligent Power Module), 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-MOSFET) as switching devices for both 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 situations, making SiC power devices one of the indispensable key components in intelligent power modules. However, in practical applications, SiC power devices inevitably have to work under overload, desaturation and other working conditions that cause short circuits in 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 easy to be falsely triggered. This requires that they must have short-circuit fault protection capabilities to protect themselves and the integrated circuits used, and 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] The existing intelligent power module does not have short-circuit detection and protection circuits for switching devices such as IGBT and SiC-MOSFET. The existing solution is to detect switching devices such as IGBT and SiC-MOSFET in the intelligent power module through a peripheral circuit, and transmit them together with other short-circuit detection signals in the peripheral circuit to the ITRIP end 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] Since the data is sampled by the peripheral circuit 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 false triggering of the SiC power device is avoided, the SiC power device is subjected to 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 tolerance time, the short-circuit protection action time should 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 needed, which is integrated in the intelligent power module to achieve fast and accurate action protection for short-circuit faults (such as overload, desaturation and other short-circuit faults). Summary of the invention

[0005] In view of 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 can provide short-circuit protection for all internal SiC power devices, and 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 integrated with short-circuit protection of SiC power devices, comprising a plurality of SiC power devices; further comprising a driving unit, a short-circuit voltage adaptation unit, an OR gate U4 and a plurality of short-circuit protection action units; the input ends of the plurality of short-circuit protection action units are electrically connected to the plurality of driving ends of the driving unit in a one-to-one correspondence, the output end of the short-circuit protection action unit is electrically connected to the driving end of the SiC power device, the driving ends of the plurality of SiC power devices are electrically connected to the plurality of input ends of the OR gate U4, the output end of the OR gate U4 is electrically connected to the feedback end of the short-circuit voltage adaptation unit, the conduction voltage ends of the plurality of SiC power devices are electrically connected to the plurality of input ends of the short-circuit voltage adaptation unit, and the trigger ends of the plurality of short-circuit protection action units are electrically connected to the output end 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 receiving the short-circuit trigger signal;

[0009] The short-circuit voltage adaptation unit is used to monitor the on-voltage of the plurality of SiC power devices in real time; when any one of the on-voltages 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-voltage is inversely proportional to the magnitude of the blanking time.

[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-type 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-type judgment circuit via the isolation circuit;

[0014] The trigger judgment circuit is used to judge that the value decreases when receiving the conduction voltage, and the magnitude of the conduction voltage and the decreasing speed of the judgment value are linearly proportional; if the judgment value decreases to less than the second threshold voltage, the short circuit trigger signal is generated; the time when the trigger judgment circuit decreases 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 a feedback end of the trigger judgment circuit, one end of the resistor R6 is used as an input end of the trigger judgment circuit, and the output end of the NOT gate U3 is used as an 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 tube M1 are all electrically connected to the negative input end of the comparator A2, the gate of the MOS tube M1 is electrically connected to the output end of the NOT gate U5, the drain of the MOS tube 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 a trigger end of the short-circuit protection action unit, the second input end of the AND gate U5 is used as an input end of the short-circuit protection action unit, and the output end of the AND gate U5 is used as an output end of the short-circuit protection action unit.

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

[0020] The 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 the on-voltage is received, the judgment value rises, and the magnitude of the on-voltage and the rising speed of the judgment value are linearly proportional; 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] Further, 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 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;

[0025] Alternatively, the resistor element R1 is a series resistor circuit with a total resistance value 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 is electrically connected to one end of the next small resistor, 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 present invention may include the following beneficial effects: a short-circuit protection mechanism consisting of a short-circuit voltage adaptation unit, an OR gate U4 and a plurality of short-circuit protection action units is integrated into an intelligent power module, all internal SiC power devices are detected in real time, and a blanking time that can adapt to different bus voltages is set to perform fast and accurate short-circuit protection actions, which is more suitable for the integrated environment of multiple SiC power devices and improves the short-circuit protection efficiency of the intelligent power module.

[0027] Specifically, Figure 3 For example, SiC power devices in intelligent power modules are mainly used in inverter units. Figure 3 It is the electrical connection method of two SiC power devices on a group of bridge arms of the inverter unit in the intelligent power module; Taking SiC-MOSFET as an example of SiC power device, the gate of SiC-MOSFET is used as the driving end of SiC power device, the drain of SiC-MOSFET is used as the positive electrode of the on-voltage end of SiC power device, and the source of SiC-MOSFET is used as the negative electrode of the on-voltage end of SiC power device, then SiC-MOSFET works normally under the drive of the driving unit; when SiC-MOSFET has a short-circuit fault such as overload or desaturation, it will cause the voltage between the drain and source of SiC-MOSFET (i.e., the on-voltage) to rise to the voltage of the bus to which it is connected, then the higher the bus voltage, the longer the tolerance time of SiC-MOSFET. short; therefore, the on-voltage of the SiC power device is monitored in real time through the short-circuit voltage adaptation unit. When the on-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, and the short-circuit protection action unit shuts down the SiC power device to achieve protection, thereby preventing false triggering of the short-circuit protection; and since the on-voltage and the blanking time are in a linear inverse proportional relationship, compared to the RC charge and discharge circuit that makes the on-voltage (short-circuit voltage) and 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-voltages, thereby making the blanking time more adaptable to different bus voltages; ultimately making the short-circuit protection more accurate and more in line with the performance requirements of SiC power devices. 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, and is used to maintain the short-circuit protection action of the short-circuit voltage adaptation unit and the short-circuit protection action unit when the short-circuit fault has not disappeared, and keep the SiC power device turned off, that is, the OR gate U4 outputs a high level when it detects that any SiC power device is short-circuited. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The circuit diagram of an intelligent power module integrated with short-circuit protection of SiC power devices according to one embodiment of the present invention is shown.

[0029] Figure 2 Yes Figure 1 A partial circuit schematic diagram at location A of an intelligent power module integrated with short-circuit protection of SiC power devices 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: driving 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] Embodiments of the present invention are described in detail below, examples of which 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 only used to explain the present invention, and cannot be understood 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 are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] In the description of the embodiments of the present invention, it should be noted that, 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 directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0036] Combine the following 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; further comprising a driving 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 ends of the plurality of short-circuit protection action units 3 are electrically connected to the plurality of driving ends of the driving unit 1 in a one-to-one correspondence, the output ends of the short-circuit protection action units 3 are electrically connected to the driving ends of the SiC power devices 4, the driving ends of the plurality of SiC power devices 4 are electrically connected to the plurality of input ends of the OR gate U4, the output end of the OR gate U4 is electrically connected to the feedback end of the short-circuit voltage adaptation unit 2, the conduction voltage ends of the plurality of SiC power devices 4 are electrically connected to the plurality of input ends of the short-circuit voltage adaptation unit 2, and the trigger ends of the plurality of short-circuit protection action units 3 are electrically connected to the output end 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 receiving a short-circuit trigger signal;

[0039] The short-circuit voltage adaptation unit 2 is used to monitor the on-voltage of multiple SiC power devices 4 in real time; when any on-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; the size of the on-voltage and the size 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 composed of the short-circuit voltage adaptation unit 2, the OR gate U4 and multiple short-circuit protection action units 3 is integrated into the intelligent power module, which 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, which 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 an 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 SiC-MOSFET is used as the driving end of SiC power device 4, the drain of SiC-MOSFET is used as the positive electrode of the on-voltage end of SiC power device 4, and the source of SiC-MOSFET is used as the negative electrode of the on-voltage end of SiC power device 4, then 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 SiC-MOSFET (i.e., the on-voltage) to increase to the voltage of the bus to which it is connected, then the higher the bus voltage, the longer the tolerance time of SiC-MOSFET. short; therefore, the on-voltage of the SiC power device 4 is monitored in real time through the short-circuit voltage adaptation unit 2. When the on-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 shuts down the SiC power device 4 to achieve protection, thereby preventing false triggering of the short-circuit protection; and since the on-voltage and the blanking time are in a linear inverse proportional relationship, compared to the RC charge and discharge circuit that makes the on-voltage (short-circuit voltage) and the blanking time in a parabolic inverse proportional relationship (that is, in the face of different short-circuit voltages, the blanking time changes very little), in the face of different on-voltages, the blanking time changes linearly, thereby making the blanking time more adaptable to different bus voltages; ultimately making the short-circuit protection 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 short-circuited.

[0042] It should be noted that as long as any SiC power device 4 integrated inside the intelligent power module has a short circuit fault, the entire inverter unit will fail. Therefore, as long as any SiC power device 4 has a short circuit fault, all SiC power devices 4 will be turned off.

[0043] Further, 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 ends of the multiple trigger-type acquisition circuits 21 are electrically connected to the multiple input ends of the isolation circuit 22 respectively, and the output end of the isolation circuit 22 is electrically connected to the input end 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 used to judge that the value decreases when receiving the conduction voltage, and the magnitude of the conduction voltage and the decreasing speed of the judgment value are linearly proportional; if the judgment value decreases to less than the second threshold voltage, a short circuit trigger signal is generated; the time when 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 blanking time generated according to the linear inverse relationship between the magnitude of the conduction voltage, the short-circuit threshold voltage is set to two thresholds, the first threshold voltage and the second threshold voltage, to limit the blanking time; wherein the first threshold voltage is a 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 a trigger value used by the trigger judgment circuit 23 to determine whether it is a permanent fault. The trigger value of a permanent short circuit fault, after the trigger judgment circuit 23 receives the on-voltage, the internal judgment value decreases accordingly, and the decreasing speed of the judgment value is linearly proportional to the size of the on-voltage. If the judgment value decreases to less than the second threshold voltage, a short circuit trigger signal is generated (representing a permanent short circuit fault); it can be seen that the time when the trigger judgment circuit 23 drops to less than the second threshold voltage is the blanking time, from which the relationship can be obtained: decreasing speed = second threshold voltage / blanking time, it can be deduced that the size of the on-voltage (short-circuit voltage) and the size 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 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 a feedback end of the trigger judgment circuit 23, one end of the resistor R6 is used as an input end of the trigger judgment circuit 23, and the output end of the NOT gate U3 is used 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 tube M1 are all electrically connected to the negative input end of the comparator A2, the gate of the MOS tube M1 is electrically connected to the output end of the NOT gate U5, the drain of the MOS tube 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.

[0053] In this embodiment, the second threshold voltage of the trigger judgment circuit 23 is the trigger value of the Schmitt trigger U2, and the active integration circuit composed of the NOT gate U1, MOS tube M1, resistor R6, resistor R7, resistor R8, capacitor C1 and comparator A2 realizes its function. 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), and 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 It can be seen from the multiple curves in that each curve represents a bus voltage connected to the SiC power device 4, the blanking time is t1, and the slope is the falling speed of the output voltage Vc. At the same time, after the SiC power device 4 is turned off, the MOS tube M1 is used to feedback the turn-off status of the SiC power device 4, so that the MOS tube M1 is turned on, and the resistor R8 provides a discharge circuit for the capacitor C1 to prepare for the next short circuit judgment.

[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 a trigger end of the short-circuit protection action unit 3, the second input end of the AND gate U5 is used as an input end of the short-circuit protection action unit 3, and the output end of the AND gate U5 is used as an 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 opening and closing of the SiC power device 4 according to the driving signal during normal operation and keep it 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. When working normally, the Schmitt trigger U2 always outputs a low level, and after the NOT gate U3 is inverted, the output of the AND gate U5 is consistent with the driving signal, and the SiC power device 4 is driven normally.

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

[0057] The 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. When the short-circuit fault conduction voltage is too large, the diode D1 can 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 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 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.

[0061] In this embodiment, the isolation circuit 22 is a voltage follower composed of a resistor R4, a resistor R5 and a comparator A1; since the impedance of the voltage-dividing resistor of the trigger-type acquisition circuit 21 is much larger than the impedance of the active integration circuit of the trigger-type judgment circuit 23, the use of a voltage follower can transmit the conduction voltage operational amplification to the active integration circuit for integration when a short circuit occurs. At the same time, the voltage follower can also play the role of isolation and buffering, and play the function of electrical isolation.

[0062] Furthermore, the trigger judgment circuit 23 is used to, when receiving the on-voltage, the judgment value rises, and the magnitude of the on-voltage and the rising speed of the judgment value are linearly proportional; if the judgment value rises to be greater than the second threshold voltage, a short-circuit trigger signal is generated; the time for the trigger judgment circuit 23 to rise to be greater than the second threshold voltage is the blanking time.

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

[0064] Further, 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 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] Alternatively, the resistor element R1 is a series resistor circuit whose total resistance is much greater than the resistance of the resistor R2. The series resistor circuit is composed of multiple small resistors in series, the other end of the previous small resistor is electrically connected to one end of the next small resistor, 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.

[0066] In this embodiment, the resistance value of the resistor R1 is much greater than the resistance value of the resistor R2 to form a voltage divider circuit, which can improve the acquisition accuracy.

[0067] Other structures and operations of an intelligent power module integrated with short-circuit protection of SiC power devices according to an embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0068] In the description of this specification, the description with reference to the terms "embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation 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] Although the 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 present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An intelligent power module with integrated short-circuit protection of SiC power devices, comprising a plurality of 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 receiving the short-circuit trigger signal; The short-circuit voltage adaptation unit is used to monitor the on-voltage of the plurality of SiC power devices in real time; when any one of the on-voltages 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-voltage is inversely proportional to the magnitude of the blanking time.

2. The intelligent power module with integrated short-circuit protection of SiC power devices according to claim 1, characterized in that: 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; 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-type 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-type judgment circuit via the isolation circuit; The trigger judgment circuit is used for judging that the value decreases when the conduction voltage is received, and the magnitude of the conduction voltage and the decreasing speed of the judgment value are in linear proportional relationship; if the judgment value decreases to be less than the second threshold voltage, the short circuit trigger signal is generated; The time for the trigger judgment circuit to drop to a voltage lower than 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.

3. The intelligent power module with integrated SiC power device short-circuit protection according to claim 2, 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 a feedback end of the trigger judgment circuit, one end of the resistor R6 is used as an input end of the trigger judgment circuit, and the output end of the NOT gate U3 is used as an 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 tube M1 are all electrically connected to the negative input end of the comparator A2, the gate of the MOS tube M1 is electrically connected to the output end of the NOT gate U5, the drain of the MOS tube 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.

4. 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.

5. The intelligent power module with integrated SiC power device short-circuit protection according to claim 2, characterized in that: The trigger type acquisition circuit comprises a diode D1, a diode D2, a resistor R2 and a resistor element R1; the cathode of the diode D1 is used as the positive electrode of the input end of the trigger type acquisition circuit, one end of the resistor R2 is used as the negative electrode of the input end of the trigger type acquisition circuit, and the anode of the diode D2 is used as the output end of the trigger type acquisition circuit; The 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 .

6. The intelligent power module with integrated SiC power device short-circuit protection according to claim 2, 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.

7. The intelligent power module integrated with short-circuit protection of SiC power devices according to claim 2, characterized in that: The trigger judgment circuit is used to, when receiving the on-state voltage, increase the judgment value, and the magnitude of the on-state voltage and the rising speed of the judgment value are linearly proportional; 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.

8. The intelligent power module integrated with short-circuit protection of SiC power devices according to claim 5, characterized in that: The resistor R1 is a single large resistor with a resistance value much 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; Alternatively, the resistor element R1 is a series resistor circuit with a total resistance value 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 is electrically connected to one end of the next small resistor, 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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