Over-current protection method and device of silicon carbide power device, and storage medium
By setting current thresholds and thermal risk assessment windows in silicon carbide power devices, and actively suppressing wave-by-wave current limiting, the thermal damage problem of silicon carbide power devices is solved, and reliable overcurrent protection is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 西安图为电气技术有限公司
- Filing Date
- 2026-03-24
- Publication Date
- 2026-05-05
AI Technical Summary
Existing wave-by-wave current limiting protection methods can cause thermal damage or thermal failure in silicon carbide power devices, especially under high current conditions where the high loss of the body diode leads to a sharp rise in junction temperature.
By acquiring the real-time current of the silicon carbide power device, setting the first and second preset current thresholds, and maintaining drive during the thermal risk assessment window, the device actively suppresses wave-by-wave current limiting to prevent current commutation to the high-loss body diode, and adopts a dual-mode response mechanism for thermal stress management.
It effectively avoids thermal damage or thermal failure of silicon carbide power devices, improves the reliability and dynamic performance of overcurrent protection, and realizes the safe protection of silicon carbide power devices.
Smart Images
Figure CN121984486A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power electronic control technology, and in particular to an overcurrent protection method, device, and storage medium for silicon carbide power devices. Background Technology
[0002] In power converters based on silicon-based insulated gate bipolar transistors (IGBTs), "wave-by-wave current limiting" is a classic and efficient overcurrent protection method. Its basic principle is to detect the current of the power device in real time during each switching cycle. Once the current exceeds the set threshold, the remaining drive signal in that cycle is immediately forcibly turned off, forcing the current to be commutated to the freewheeling diode connected in antiparallel to the IGBT. Since the freewheeling diode is an independent device specifically optimized for efficient conduction, its forward voltage drop is low. Therefore, this protection method can effectively limit the current peak without introducing unacceptable additional losses.
[0003] However, with the development of wide bandgap semiconductor devices, especially the widespread application of silicon carbide power devices, the above method is no longer applicable. When wave-by-wave current limiting protection is applied to silicon carbide power devices, the current is forced to be switched from the low-resistance MOSFET channel to the high-loss body diode. Under high current conditions, the instantaneous power consumption generated by the body diode is extremely large, which causes the junction temperature of the silicon carbide power device to rise sharply in a short period of time. In turn, the protection action causes thermal damage or thermal failure of the device. Summary of the Invention
[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, this invention proposes an overcurrent protection method and apparatus, and a storage medium for silicon carbide power devices, which can effectively and reliably achieve overcurrent protection for silicon carbide power devices.
[0005] In a first aspect, embodiments of the present invention provide an overcurrent protection method for silicon carbide power devices, comprising: When the silicon carbide power device is driven to conduct, the real-time current flowing through the silicon carbide power device is acquired; When the real-time current is detected to be greater than or equal to the first preset current threshold and less than the second preset current threshold, the silicon carbide power device will continue to be driven within the subsequent preset thermal risk assessment window period. Wherein, the first preset current threshold is less than the second preset current threshold; The first preset current threshold is set according to the following conditions: The heat accumulation generated by the silicon carbide power device continuously conducting within the thermal risk assessment window period at the first preset current threshold continuously approaches but does not exceed the initial value of the thermal accumulation risk of the silicon carbide power device. The second preset current threshold is set according to the following conditions: The heat accumulation generated by the silicon carbide power device continuously conducting during the thermal risk assessment window period at the second preset current threshold reaches the thermal accumulation safety limit value of the silicon carbide power device.
[0006] Optionally, in one embodiment of the present invention, during the thermal risk assessment window, the method further includes: The real-time current of the silicon carbide power device is continuously monitored until the entire thermal risk assessment window period has elapsed; If, after the entire thermal risk assessment window period has been completed, the silicon carbide power device is turned off when it is determined that the real-time current at any moment during the thermal risk assessment window period is greater than or equal to the first preset current threshold; or, if it is determined that the real-time current at at least one moment during the thermal risk assessment window period is less than the first preset current threshold, the silicon carbide power device is kept driven.
[0007] Optionally, in one embodiment of the present invention, the method further includes: When the real-time current is detected to be greater than or equal to the second preset current threshold, wave-by-wave current limiting is applied to the silicon carbide power device.
[0008] Optionally, in one embodiment of the present invention, when wave-by-wave current limiting is applied to the silicon carbide power device, the method further includes: An emergency event counter is started, and the count value of the emergency event counter is incremented by 1 for each switching cycle of the silicon carbide power device. When the count value of the emergency event counter reaches the preset count threshold, the silicon carbide power device is turned off.
[0009] Optionally, in one embodiment of the present invention, the method further includes: During the thermal risk assessment window, the real-time junction temperature of the silicon carbide power device is continuously monitored; When the real-time junction temperature is detected to reach the preset target junction temperature at a certain moment, the silicon carbide power device is turned off.
[0010] Optionally, in one embodiment of the present invention, the thermal risk assessment window period adopts N switching cycles of the silicon carbide power device, wherein N is associated with the thermal capacity and specific power loss of the silicon carbide power device, wherein the specific power loss is generated by the body diode of the silicon carbide power device when the real-time current is the first preset current threshold.
[0011] Secondly, embodiments of the present invention provide an overcurrent protection device for a silicon carbide power device, comprising: A current sampling unit is used to acquire the real-time current flowing through the silicon carbide power device when the silicon carbide power device is driven to conduct. The drive control unit is used to maintain the drive of the silicon carbide power device within a subsequent preset thermal risk assessment window period when the real-time current is detected to be greater than or equal to a first preset current threshold and less than a second preset current threshold. Wherein, the first preset current threshold is less than the second preset current threshold; The first preset current threshold is set according to the following conditions: The heat accumulation generated by the silicon carbide power device continuously conducting within the thermal risk assessment window period at the first preset current threshold continuously approaches but does not exceed the initial value of the thermal accumulation risk of the silicon carbide power device. The second preset current threshold is set according to the following conditions: The heat accumulation generated by the silicon carbide power device continuously conducting during the thermal risk assessment window period at the second preset current threshold reaches the thermal accumulation safety limit value of the silicon carbide power device.
[0012] Thirdly, embodiments of the present invention provide an electronic device, comprising: At least one processor; At least one memory for storing at least one program; When at least one of the programs is executed by at least one of the processors, the overcurrent protection method for silicon carbide power devices as described in the first aspect is implemented.
[0013] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing a processor-executable program, which, when executed by a processor, is used to implement the overcurrent protection method for silicon carbide power devices as described in the first aspect.
[0014] This invention proposes an overcurrent protection method, device, and storage medium for silicon carbide power devices. When the silicon carbide power device is driven to conduct, the real-time current flowing through the silicon carbide power device is acquired to further determine the overcurrent nature of the real-time current. Considering the different thermal stress risks of silicon carbide power devices, a first preset current threshold, a second preset current threshold, and a thermal risk assessment window period matched with the first preset current threshold are set accordingly. Thus, when the real-time current is within the current range between the first and second preset current thresholds, the silicon carbide power device can be driven continuously during the subsequent thermal risk assessment window period. This achieves active suppression of wave-by-wave current limiting and creatively avoids the current being forced to commutate to the high-loss body diode, that is, actively avoids the body diode conduction in this situation. It fundamentally eliminates the "self-destructive" thermal damage or thermal failure problem that is easily caused by related prior art on silicon carbide power devices, and can effectively and reliably achieve overcurrent protection for silicon carbide power devices. Attached Figure Description
[0015] Figure 1 This is a flowchart of an overcurrent protection method for silicon carbide power devices provided in an embodiment of the present invention; Figure 2 This is a flowchart of an overcurrent protection method for silicon carbide power devices provided in another embodiment of the present invention; Figure 3 This is a flowchart of an overcurrent protection method for silicon carbide power devices provided in another embodiment of the present invention; Figure 4 This is a flowchart of an overcurrent protection method for silicon carbide power devices provided in another embodiment of the present invention; Figure 5 This is a schematic diagram of the execution flow of an overcurrent protection method for silicon carbide power devices provided in an embodiment of the present invention; Figure 6 This is a circuit topology schematic diagram of a silicon carbide power device provided in an embodiment of the present invention; Figure 7(a) is a schematic diagram of the driving waveform of a silicon carbide power device provided in an embodiment of the present invention; Figure 7(b) is a schematic diagram of the driving waveform of a silicon carbide power device provided in another embodiment of the present invention; Figure 7(c) is a schematic diagram of the driving waveform of a silicon carbide power device provided in another embodiment of the present invention; Figure 8 This is a schematic diagram of the overcurrent protection device for a silicon carbide power device provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation
[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0017] It should be noted that although functional modules are divided in the device schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart.
[0018] Figure 1 This is a flowchart illustrating an overcurrent protection method for a silicon carbide power device according to an embodiment of the present invention. Figure 1 As shown, the overcurrent protection method for the silicon carbide power device may include, but is not limited to, steps S1 to S2.
[0019] Step S1: When the silicon carbide power device is driven to conduct, the real-time current flowing through the silicon carbide power device is acquired. The application scenario of the silicon carbide power device (including its specifications, parameters, and circuit topology) is not limited and can be set by those skilled in the art according to actual needs. This embodiment only focuses on its overcurrent protection. The method of acquiring the real-time current flowing through the silicon carbide power device can be set according to the actual scenario and is not limited here. For example, it is possible to directly collect the current flowing through the silicon carbide power device, or to collect the equivalent current flowing through the silicon carbide power device on the corresponding branch, etc. It should be noted that when a silicon carbide power device is driven to conduct, it means that the silicon carbide power device is being driven normally. This means that the original pulse width modulation (PWM) signal is maintained to control the silicon carbide power device, so that its channel remains in a low-resistance conducting state. In this case, the current will not be commutated to its body diode. Step S2: When the real-time current is detected to be greater than or equal to the first preset current threshold and less than the second preset current threshold, the silicon carbide power device is driven within the subsequent preset thermal risk assessment window period, that is, the normal driving of the silicon carbide power device is maintained.
[0020] Wherein, the first preset current threshold is less than the second preset current threshold; The first preset current threshold is set according to the following conditions: The heat accumulation generated by the silicon carbide power device continuously conducting at a first preset current threshold during the thermal risk assessment window period continuously approaches but does not exceed the initial value of the thermal accumulation risk of the silicon carbide power device. The second preset current threshold is set according to the following conditions: The heat accumulation generated by the silicon carbide power device continuously conducting at a second preset current threshold during the thermal risk assessment window reaches the thermal accumulation safety limit value of the silicon carbide power device.
[0021] In other words, at the current level of the first preset current threshold, if the current is commutated to the body diode of the silicon carbide power device and continues to flow, the resulting losses may begin to accumulate significant thermal stress; the second preset current threshold can be equivalent to: the transient current limit that the silicon carbide power device can withstand or the defined short-circuit current threshold.
[0022] In other words, although the first and second preset current thresholds fall under the category of current thresholds, they are specifically used to assess the thermal stress risk of silicon carbide power devices. Furthermore, the thermal risk assessment window is not a simple delay window, but rather equivalent to the allowable thermal accumulation budget time for the silicon carbide power device. The values of the thermal risk assessment window and the first preset current threshold can be determined by considering various factors such as the silicon carbide power device's packaging, heat dissipation conditions, and operating status. These two parameters represent the silicon carbide power device's ability to operate continuously under overcurrent conditions without exceeding the safe boundary of thermal stress, rather than merely detecting overcurrent. This is completely different from the design philosophy of current thresholds in existing technologies. Only when the real-time current is greater than or equal to the first preset current threshold and less than the second preset current threshold can optimal management of the thermal stress of the body diode be achieved without sacrificing rapid protection capabilities. This is something that a simple delay scheme with a single threshold cannot achieve.
[0023] In this step, when the silicon carbide power device is driven to conduct, the real-time current flowing through the silicon carbide power device is acquired to further determine the overcurrent nature of the real-time current. Considering the different thermal stress risks of the silicon carbide power device, a first preset current threshold, a second preset current threshold, and a thermal risk assessment window period matched with the first preset current threshold are set accordingly. Thus, when the real-time current is within the current range between the first preset current threshold and the second preset current threshold, the silicon carbide power device can be driven during the subsequent thermal risk assessment window period. This achieves active suppression of wave-by-wave current limiting and creatively avoids the current being forced to commutate to the high-loss body diode. That is, it actively avoids the conduction of the body diode in this situation, fundamentally eliminating the "self-destructive" thermal damage or thermal failure problem that is easily caused by related existing technologies on silicon carbide power devices. It can effectively and reliably achieve overcurrent protection for silicon carbide power devices.
[0024] like Figure 2 As shown, in one embodiment of the present invention, during the thermal risk assessment window, the following steps may be included, but are not limited to: Step S3: Continuously monitor the real-time current of the silicon carbide power device until the entire thermal risk assessment window period has passed; Step S4: After the entire thermal risk assessment window period has been completed, if it is determined that the real-time current at any moment during the thermal risk assessment window period is greater than or equal to the first preset current threshold, the silicon carbide power device is turned off; or, if it is determined that the real-time current at at least one moment during the thermal risk assessment window period is less than the first preset current threshold, the silicon carbide power device is kept driven.
[0025] In this step, the silicon carbide power device is not immediately shut off during the thermal risk assessment window. Instead, it is allowed to continue conducting normally according to the original modulation signal. The trigger condition for the thermal risk management mode is that the real-time current is between the first preset current threshold and the second preset current threshold. Under this condition, the wave-by-wave current limiting protection is intentionally suppressed, and the real-time current of the silicon carbide power device is continuously monitored until the entire thermal risk assessment window has elapsed. Then, it is determined whether the overcurrent is transient and self-recoverable or continuously depletes the thermal budget. Specifically, after the entire thermal risk assessment window has elapsed, if the real-time current at any moment within the thermal risk assessment window is greater than or equal to the first preset current threshold, it indicates that the real-time current is consistently not less than the first preset current threshold. If the current threshold is exceeded, it is determined to be a continuous overload fault, and the risk of thermal accumulation has been confirmed. At this time, the thermal risk management mode is exited, and full wave blocking protection is executed, that is, the silicon carbide power devices are shut down. Alternatively, as long as the real-time current is detected to fall below the first preset current threshold at least once during the thermal risk assessment window, it indicates that the overcurrent is temporary and self-recoverable. At this time, the thermal risk management mode can be completely exited without any protection action, achieving lossless ride-through. It can be seen that the control method of this embodiment allows the entire system to safely pass through short-term, non-faulty current surges (such as sudden load increases, motor starts, etc.), reducing false protection, improving availability and dynamic performance, while still providing rapid and reliable protection for true continuous overloads.
[0026] In one embodiment, the thermal risk assessment window period may, but is not limited to, using N switching cycles of silicon carbide power devices, where N is related to the thermal capacity and specific power loss of the silicon carbide power devices. The specific power loss is generated by the body diode of the silicon carbide power device when the real-time current is a first preset current threshold. Generally speaking, the larger the thermal capacity of the silicon carbide power device, the larger N is, or the larger the specific power loss of the silicon carbide power device, the smaller N is. This embodiment does not impose specific limitations on the fixed relationship between N and the thermal capacity and specific power loss of the silicon carbide power device, and can be set accordingly by those skilled in the art according to the actual application scenario.
[0027] In one embodiment, when N switching cycles of silicon carbide power devices are used during the thermal risk assessment window, steps S3 to S4 can be implemented, but are not limited to, in the following ways: A thermal risk assessment counter is started, and the count value of the thermal risk assessment counter is incremented by 1 after each switching cycle of the silicon carbide power device until the final count value of the thermal risk assessment counter reaches N. If the real-time current is detected to drop below the first preset current threshold at any moment, the count of the thermal risk assessment counter is cleared to zero, and the silicon carbide power device is controlled to exit the thermal risk management mode. Alternatively, if the count value of the thermal risk assessment counter reaches N and the real-time current still remains not less than the first preset current threshold, then full wave blocking protection is performed.
[0028] like Figure 3 As shown in one embodiment of the present invention, the overcurrent protection method for the silicon carbide power device may further include, but is not limited to, the following steps: Step S5: During the thermal risk assessment window, continuously monitor the real-time junction temperature of the silicon carbide power device; Step S6: When the real-time junction temperature at a certain moment is detected to reach the preset target junction temperature, turn off the silicon carbide power device.
[0029] In this step, during the thermal risk assessment window, the real-time junction temperature of the silicon carbide power device is monitored to determine whether it has reached the critical level of thermal stress risk. That is, when the real-time junction temperature at a certain moment reaches the preset target junction temperature, it indicates that the real-time junction temperature of the silicon carbide power device is at a high level and the thermal stress risk is high. It is necessary to shut it down to prevent it from exceeding the short-term safe junction temperature limit, thereby protecting itself from damage.
[0030] In one embodiment, the target junction temperature can be determined based on, but is not limited to, the performance and parameters of the silicon carbide power device itself. For example, the target junction temperature can be determined and set by factory settings. No limitation is imposed here.
[0031] In one embodiment of the present invention, the overcurrent protection method for the silicon carbide power device may further include, but is not limited to, the following steps: Step S7: When the real-time current is detected to be greater than or equal to the second preset current threshold, the silicon carbide power device is subjected to wave-by-wave current limiting.
[0032] It can be seen that if the real-time current is detected to be greater than or equal to the second preset current threshold, it indicates that the thermal stress or instantaneous current of the silicon carbide power device is approaching the device limit and is in a relatively dangerous working state. Therefore, wave-by-wave current limiting is performed on the silicon carbide power device to achieve the protection purpose. In other words, compared with the overcurrent detection-triggered wave-by-wave current limiting method in the relevant prior art, the embodiments of the present invention are upgraded to assessing thermal risk and achieving thermal stress boundary shutdown. Specifically, when the real-time current is between the first preset current threshold and the second preset current threshold, the thermal risk management mode is entered, and when the real-time current exceeds the second preset current threshold, the emergency protection mode is entered. Through the coordinated work of such a dual-mode response mechanism, the thermal stress of the silicon carbide power device can be optimized and managed without sacrificing the rapid protection capability, thereby improving the reliability of the overcurrent protection of the silicon carbide power device.
[0033] like Figure 4 As shown, in one embodiment of the present invention, when performing wave-by-wave current limiting on silicon carbide power devices, the following steps may also be included, but are not limited to: Step S8: Start the emergency event counter, and increment the count value of the emergency event counter by 1 for each switching cycle of the silicon carbide power device. Step S9: When the count value of the emergency event counter reaches the preset count threshold, turn off the silicon carbide power device. The preset count threshold can be set according to the actual scenario and is not restricted.
[0034] In this step, the emergency event counter can be denoted as M. When the count value of M accumulates to the preset count threshold, it is determined to be an unrecoverable fault, and complete wave blocking protection is performed, that is, the drive is permanently shut down. Conversely, if the fault has disappeared before the preset count threshold is reached, the count value of M can be gradually decreased or reset. In particular, when the preset count threshold is set to 1, it means that as long as the real-time current flowing through the silicon carbide power device is detected to exceed the second preset current threshold, effective drive will be stopped immediately, and immediate protection will be performed. This is suitable for scenarios where instantaneous blocking of ultra-high current is required.
[0035] To better illustrate the working principle of the above embodiments, the following is combined with... Figure 5 and Figure 6 Specific examples are given to illustrate this, in which, Figure 5 This is a schematic diagram of the execution flow of an overcurrent protection method for a silicon carbide power device according to an embodiment of the present invention. Figure 6 The circuit topology diagram for using silicon carbide power devices is provided in one embodiment of the present invention.
[0036] like Figure 5 As shown, the real-time current I of the silicon carbide power device (i.e., SiC MOSFET) is first detected and processed in two cases: 1. If \(I1\leq I < I2\), it is determined that the current is currently in the light overcurrent / risk area. It is necessary to actively inhibit the per-wave current limiting to keep the SiC MOSFET conducting normally, so as to use the low resistance of the SiC MOSFET channel to carry the current to avoid the conduction of the body diode. Moreover, on this basis, within the thermal risk assessment window period constructed based on the switching cycles of N SiC MOSFETs, start the thermal risk assessment counter for cumulative counting. When the count reaches the maximum value, that is, when the count reaches N, if the real-time current I is still detected to continuously exceed I1, it is determined as a continuous fault and full wave blocking is performed. Otherwise, if it is determined that the current has dropped back below I1, it is determined as a transient overload, and the count is cleared to achieve non-damaging recovery; Among them, I1 is the first preset current threshold, and I2 is the second preset current threshold; 2. If \(I > I2\), it is determined that the current may be in a severe overcurrent / short circuit situation, and it is necessary to immediately perform per-wave current limiting to sacrifice the body diode to ensure safety. Moreover, on this basis, within the thermal risk assessment window period constructed based on the switching cycles of N SiC MOSFETs, start the emergency event counter M for cumulative counting. When M reaches the set value, that is, full wave blocking is performed to achieve the protection purpose, otherwise continue to monitor the real-time current I.
[0037] As Figure 6 shown, taking the inverter bridge arm using SiC MOSFET as an example, the drain current of the lower bridge arm SiC MOSFET can be obtained through a shunt resistor or a Hall sensor. The rated current of the selected SiC MOSFET device is 100A. At the same time, I1 is set to 150A, and this value is determined through device thermal model simulation. The basis is that when the current continuously commutates from the channel to the body diode, it will cause a significant increase in the junction temperature within about 10us. I2 is set to 300A (i.e., 3 times the rated value), corresponding to the hardware short circuit protection requirement. N corresponding to the thermal risk assessment window period is set to 6 (the switching frequency is 50kHz, and the corresponding time window is 120us). This value is determined through device thermal model simulation. The basis is that at a current of 150A, the temperature rise generated by the continuous conduction of the body diode for 120us is close to but does not exceed its short-term safe junction temperature limit.
[0038] The specific working process is as follows: 1. Scenario 1: When the detected current enters the 150A - 300A range, immediately prohibit the output of the conventional per-wave current limiting; at the same time, start the thermal risk assessment counter and maintain the normal PWM drive signal output to the SiC MOSFET. As shown in Figure 7(a), since it is a load mutation, the current adjusts I to 140A (<I1) within 6 counting cycles, then the thermal risk assessment counter is decremented to zero, and no protection actions are triggered throughout the process. The body diode of the SiC MOSFET never conducts, and the device temperature rise is gentle; 2. Scenario 2: As shown in Figure 7(b), if I is detected to be greater than I1 for 6 consecutive counting cycles, the safety boundary of thermal risk assessment is reached, a control signal for complete wave blocking is issued, the drive is permanently shut down and a fault code is reported. 3. Scenario 3: When I exceeds 300A, current limiting is immediately implemented. The drive is forcibly shut down in the first cycle, causing the current to be commutated to the body diode. At the same time, M starts to accumulate. Since the current sampling value in each counting cycle exceeds I2, M accumulates rapidly. When M accumulates to a set value (e.g., 3), it is determined to be an unrecoverable fault. A control signal for complete wave blocking is issued, the drive is permanently shut down and a fault code is reported. This process is completed within tens of microseconds. Although the body diode conducts briefly, the overall circuit topology is safely shut down before the device thermally fails, so the impact is still relatively small. As shown in Figure 7(c), in some cases where the short-circuit response speed is extremely important, M can be set to 1. This means that once I > I2 is detected, the current limiting will be upgraded to complete blocking in the same cycle or at the beginning of the next cycle, thus achieving the fastest fault isolation.
[0039] As can be seen, this embodiment solves the core contradiction in SiC MOSFET applications. By actively suppressing wave-by-wave current limiting within the current range between I1 and I2, it creatively avoids the forced current commutation to the high-loss body diode, fundamentally eliminating the "self-destructive" thermal failure problem caused by related existing technologies in silicon carbide power devices. In particular, it achieves an innovation in protection paradigm, upgrading overcurrent protection from a simple "detection-turn-off" response mode to an intelligent "monitoring-evaluation-classification response" mode, providing an intelligent overcurrent protection solution that takes into account dynamic performance, operational reliability, and device safety.
[0040] like Figure 8 As shown, in one embodiment of the present invention, an overcurrent protection device for a silicon carbide power device is also provided, which may include, but is not limited to, the following: The current sampling unit is used to acquire the real-time current flowing through the silicon carbide power device when the silicon carbide power device is driven to conduct. The drive control unit is used to maintain the drive of the silicon carbide power device within a subsequent preset thermal risk assessment window period when the real-time current is detected to be greater than or equal to the first preset current threshold and less than the second preset current threshold. Wherein, the first preset current threshold is less than the second preset current threshold; The first preset current threshold is set according to the following conditions: The heat accumulation generated by the silicon carbide power device continuously conducting at a first preset current threshold during the thermal risk assessment window period continuously approaches but does not exceed the initial value of the thermal accumulation risk of the silicon carbide power device. The second preset current threshold is set according to the following conditions: The heat accumulation generated by the silicon carbide power device continuously conducting at a second preset current threshold during the thermal risk assessment window reaches the thermal accumulation safety limit value of the silicon carbide power device.
[0041] The overcurrent protection device for the silicon carbide power device has the same inventive concept as the overcurrent protection method for the silicon carbide power device described above. Therefore, the specific implementation of the overcurrent protection device for the silicon carbide power device is basically the same as the specific implementation of the overcurrent protection method for the silicon carbide power device described above. You can refer to the specific implementation of the overcurrent protection method for the silicon carbide power device described above. To avoid redundancy, it will not be described again here.
[0042] Figure 9 This is a schematic diagram of the structure of an electronic device 1000 provided in an embodiment of the present invention. For example... Figure 9 As shown, the electronic device 1000 includes a memory 1100 and a processor 1200. The number of memories 1100 and processors 1200 can be one or more. Figure 9 Taking a memory 1100 and a processor 1200 as an example; the memory 1100 and the processor 1200 in the device can be connected via a bus or other means. Figure 9 Taking the example of a connection between China and Israel via a bus.
[0043] The memory 1100, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the overcurrent protection method for silicon carbide power devices provided in any embodiment of the present invention. The processor 1200 implements the aforementioned overcurrent protection method for silicon carbide power devices by running the software programs, instructions, and modules stored in the memory 1100.
[0044] The memory 1100 may primarily include a program storage area and a data storage area, wherein the program storage area may store the operating system and application programs required for at least one function. Furthermore, the memory 1100 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some instances, the memory 1100 may further include memory remotely located relative to the processor 1200, and these remote memories can be connected to the device via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.
[0045] An embodiment of the present invention also provides a computer-readable storage medium storing computer-executable instructions for performing an overcurrent protection method for a silicon carbide power device as provided in any embodiment of the present invention.
[0046] An embodiment of the present invention also provides a computer program product, including a computer program or computer instructions, which are stored in a computer-readable storage medium. A processor of a computer device reads the computer program or computer instructions from the computer-readable storage medium and executes the computer program or computer instructions, causing the computer device to perform the overcurrent protection method for silicon carbide power devices as provided in any embodiment of the present invention.
[0047] The electronic devices and application scenarios described in the embodiments of this invention are for the purpose of more clearly illustrating the technical solutions of the embodiments of this invention, and do not constitute a limitation on the technical solutions provided by the embodiments of this invention. As those skilled in the art will know, with the evolution of electronic devices and the emergence of new application scenarios, the technical solutions provided by the embodiments of this invention are also applicable to similar technical problems.
[0048] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.
[0049] In hardware implementations, the division between functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.
[0050] The terms “component,” “module,” “system,” etc., used in this specification are used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, or a computer. As illustrated, applications running on computing devices and computing devices can both be components. One or more components may reside in a process or execution thread, and components may be located on a single computer or distributed among two or more computers. Furthermore, these components can be executed from various computer-readable media on which various data structures are stored. Components can communicate, for example, via local or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, or a network, such as the Internet interacting with other systems via signals).
Claims
1. An overcurrent protection method for silicon carbide power devices, characterized in that, include: When the silicon carbide power device is driven to conduct, the real-time current flowing through the silicon carbide power device is acquired; When the real-time current is detected to be greater than or equal to the first preset current threshold and less than the second preset current threshold, the silicon carbide power device will continue to be driven within the subsequent preset thermal risk assessment window period. Wherein, the first preset current threshold is less than the second preset current threshold; The first preset current threshold is set according to the following conditions: The heat accumulation generated by the silicon carbide power device continuously conducting within the thermal risk assessment window period at the first preset current threshold continuously approaches but does not exceed the initial value of the thermal accumulation risk of the silicon carbide power device. The second preset current threshold is set according to the following conditions: The heat accumulation generated by the silicon carbide power device continuously conducting during the thermal risk assessment window period at the second preset current threshold reaches the thermal accumulation safety limit value of the silicon carbide power device.
2. The overcurrent protection method for silicon carbide power devices according to claim 1, characterized in that, During the thermal risk assessment window, the method further includes: The real-time current of the silicon carbide power device is continuously monitored until the entire thermal risk assessment window period has elapsed; If, after the entire thermal risk assessment window period has been completed, the silicon carbide power device is turned off when it is determined that the real-time current at any moment during the thermal risk assessment window period is greater than or equal to the first preset current threshold; or, if it is determined that the real-time current at at least one moment during the thermal risk assessment window period is less than the first preset current threshold, the silicon carbide power device is kept driven.
3. The overcurrent protection method for silicon carbide power devices according to claim 1, characterized in that, The method further includes: When the real-time current is detected to be greater than or equal to the second preset current threshold, wave-by-wave current limiting is applied to the silicon carbide power device.
4. The overcurrent protection method for silicon carbide power devices according to claim 3, characterized in that, When performing wave-by-wave current limiting on the silicon carbide power device, the method further includes: An emergency event counter is started, and the count value of the emergency event counter is incremented by 1 for each switching cycle of the silicon carbide power device. When the count value of the emergency event counter reaches the preset count threshold, the silicon carbide power device is turned off.
5. The overcurrent protection method for silicon carbide power devices according to claim 1, characterized in that, The method further includes: During the thermal risk assessment window, the real-time junction temperature of the silicon carbide power device is continuously monitored; When the real-time junction temperature is detected to reach the preset target junction temperature at a certain moment, the silicon carbide power device is turned off.
6. The overcurrent protection method for silicon carbide power devices according to any one of claims 1 to 5, characterized in that, The thermal risk assessment window period uses N switching cycles of the silicon carbide power device, where N is related to the thermal capacity and specific power loss of the silicon carbide power device, wherein the specific power loss is generated by the body diode of the silicon carbide power device when the real-time current is the first preset current threshold.
7. An overcurrent protection device for a silicon carbide power device, characterized in that, include: A current sampling unit is used to acquire the real-time current flowing through the silicon carbide power device when the silicon carbide power device is driven to conduct. The drive control unit is used to maintain the drive of the silicon carbide power device within a subsequent preset thermal risk assessment window period when the real-time current is detected to be greater than or equal to a first preset current threshold and less than a second preset current threshold. Wherein, the first preset current threshold is less than the second preset current threshold; The first preset current threshold is set according to the following conditions: The heat accumulation generated by the silicon carbide power device continuously conducting within the thermal risk assessment window period at the first preset current threshold continuously approaches but does not exceed the initial value of the thermal accumulation risk of the silicon carbide power device. The second preset current threshold is set according to the following conditions: The heat accumulation generated by the silicon carbide power device continuously conducting during the thermal risk assessment window period at the second preset current threshold reaches the thermal accumulation safety limit value of the silicon carbide power device.
8. An electronic device, characterized in that, include: At least one processor; At least one memory for storing at least one program; When at least one of the programs is executed by at least one of the processors, the overcurrent protection method for silicon carbide power devices as described in any one of claims 1 to 6 is implemented.
9. A computer-readable storage medium, characterized in that, It stores a processor-executable program, which, when executed by the processor, is used to implement the overcurrent protection method for silicon carbide power devices as described in any one of claims 1 to 6.