Method, device and equipment for evaluating dynamic safety work area of high frequency operation

Abstract

The application belongs to the technical field of safety evaluation, and specifically discloses a kind of high-frequency operation dynamic safety work area evaluation method, device and equipment. According to the temperature characteristics and degradation information, the second current change rate and the second voltage change rate of SiC MOSFET device under the driving protection circuit are determined respectively through the application. After calculating the target current change rate combined with the first current change rate, and calculating the target voltage change rate combined with the first voltage change rate, the high-frequency operation dynamic safety work area of SiC MOSFET device is evaluated respectively. Through the above-mentioned mode, the root cause of the secondary problem of SiC MOSFET device switching transient is considered, the current change rate and the voltage change rate are selected to represent the switching rate, and the voltage and current overshoot and oscillation of the switching transient are effectively evaluated, and the safety work area is evaluated combined with the temperature characteristics and degradation information, so as to effectively improve the accuracy of evaluating the high-frequency operation dynamic safety work area.

Description

Technical Field

[0001] This application belongs to the field of safety assessment technology, and more specifically, relates to assessment methods, apparatus and equipment for high-frequency operating dynamic safety working areas. Background Technology

[0002] While meeting the evolving requirements of power electronic devices for higher temperatures, higher power densities, and higher frequencies, SiC MOSFET devices also experience higher voltages, larger on-state currents, higher switching stresses, and higher bulk and surface electric fields during operation. In high-speed switching, SiC MOSFET devices generate very high voltage and current change rates. These, coupled with parasitic parameters present in the device itself and the circuit, can lead to voltage / current overshoot and oscillations, or voltage / current spikes and glitches, resulting in increased switching losses and even device damage.

[0003] The aforementioned secondary problems are directly related to the switching speed and parasitic parameters of the devices. These problems, on the one hand, prevent the full utilization of the superior performance of SiC MOSFET devices, resulting in significant resource waste; on the other hand, they degrade the transient performance of SiC MOSFET devices, leading to instability in SiC MOSFET switching transients, increasing the failure rate of SiC MOSFETs at high frequencies, affecting the efficiency, power density, and lifespan of power electronic converters, and reducing their reliability. Therefore, evaluating the high-frequency dynamic safe operating area can fully utilize the superior high-speed switching performance of SiC MOSFET devices and effectively control the secondary problems caused by high-frequency switching. Currently, common methods for evaluating the high-frequency dynamic safe operating area rely on human experience. However, parameter settings based on experience are prone to deviations and may ignore factors such as temperature and device aging. Therefore, the accuracy of these methods in evaluating the high-frequency dynamic safe operating area is relatively low. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this application is to provide a method, apparatus and equipment for evaluating the dynamic safety working area of ​​high-frequency operation, which aims to solve the problem that the accuracy of evaluating the dynamic safety working area of ​​high-frequency operation is low due to the deviation that occurs when using human experience to set parameters.

[0005] To achieve the above objectives, in a first aspect, this application provides a method for evaluating a high-frequency operating dynamic safety working area, comprising: Obtain the first current change rate and the first voltage change rate that lead to the failure of the SiC MOSFET device; The temperature characteristics and degradation information of the SiC MOSFET device are obtained, and the second current change rate and the second voltage change rate of the SiC MOSFET device under the drive protection circuit are determined according to the temperature characteristics and the degradation information, respectively. The first current change rate and the second current change rate are intersected to obtain the target current change rate, and the first voltage change rate and the second voltage change rate are intersected to obtain the target voltage change rate. The high-frequency operating dynamic safe operating region of the SiC MOSFET device is evaluated based on the target current change rate and the target voltage change rate, respectively.

[0006] In one embodiment, the step of acquiring the temperature characteristics and degradation information of the SiC MOSFET device, and determining the second current change rate and the second voltage change rate of the SiC MOSFET device under the drive protection circuit based on the temperature characteristics and the degradation information, includes: To obtain temperature characteristics and degradation information of SiC MOSFET devices; The current and voltage change rates of the SiC MOSFET device at different temperatures were determined based on the aforementioned temperature characteristics. Based on the degradation information, determine the current and voltage change rates of the SiC MOSFET device under different degrees of degradation; When the drive protection circuit is detected to be connected to the SiC MOSFET device, a second current change rate is determined based on the current change rate of the SiC MOSFET device at different temperatures and the current change rate at different degradation levels, and a second voltage change rate is determined based on the voltage change rate of the SiC MOSFET device at different temperatures and the voltage change rate at different degradation levels.

[0007] In one embodiment, the step of determining a second current change rate based on the current change rate of the SiC MOSFET device at different temperatures and at different degradation levels when the drive protection circuit is detected to be connected to the SiC MOSFET device, and determining a second voltage change rate based on the voltage change rate of the SiC MOSFET device at different temperatures and at different degradation levels, when the temperature characteristics are determined, includes: When the drive protection circuit is detected to be connected to the SiC MOSFET device, the current temperature and current degradation level of the SiC MOSFET device are detected. The current change rate corresponding to the current temperature is determined based on the current change rate of the SiC MOSFET device at different temperatures, and the current change rate corresponding to the current degradation level is determined based on the current change rate of the SiC MOSFET device at different degradation levels. The second current change rate is determined based on the current change rate corresponding to the current temperature and the current change rate corresponding to the current degree of degradation; The voltage change rate corresponding to the current temperature is determined based on the voltage change rate of the SiC MOSFET device at different temperatures, and the voltage change rate corresponding to the current degradation level is determined based on the voltage change rate of the SiC MOSFET device at different degradation levels. The second voltage change rate is determined based on the voltage change rate corresponding to the current temperature and the voltage change rate corresponding to the current degree of degradation.

[0008] In one embodiment, the step of obtaining the first current change rate that leads to the failure of the SiC MOSFET device includes: When a SiC MOSFET device fails due to drain-source breakdown under high current change rate, the stray inductance of the circuit is obtained. The first current change rate that causes the SiC MOSFET device to fail is calculated based on the maximum voltage that the drain and source can withstand, the stray inductance of the circuit, and the bus voltage. When a SiC MOSFET device fails due to reverse recovery of the body diode under high current change rate, the reverse recovery data of the body diode is obtained. The first current change rate that causes the failure of the SiC MOSFET device is determined based on the reverse recovery data of the body diode.

[0009] In one embodiment, the step of obtaining the first voltage change rate that causes the SiC MOSFET device to fail includes: When a SiC MOSFET device fails due to parasitic NPN conduction under high voltage change rate, the junction capacitance formed in the drain base region is obtained. The first voltage change rate that causes the SiC MOSFET device to fail is calculated based on the junction capacitance formed in the drain base region, the PN junction built-in potential, and the base region resistance. When SiC MOSFET devices fail due to bridge arm punch-through caused by crosstalk in the half-bridge circuit under high voltage change rate, the target threshold voltage is obtained. The first voltage change rate that causes the SiC MOSFET device to fail is calculated based on the target threshold voltage, gate resistance, and gate-drain capacitance.

[0010] In one embodiment, the step of evaluating the high-frequency operating dynamic safe operating region of the SiC MOSFET device based on the target current change rate and the target voltage change rate respectively includes: The dynamic safe operating region of the SiC MOSFET device in the current dimension is evaluated based on the target current change rate. The target voltage change rate is used to evaluate the dynamic safe operating region of the SiC MOSFET device at high frequencies in the voltage dimension.

[0011] Secondly, this application provides an evaluation device for a high-frequency operating dynamic safety working area, comprising: The acquisition module is used to acquire the first current change rate and the first voltage change rate that cause the SiC MOSFET device to fail; The acquisition module is also used to acquire the temperature characteristics and degradation information of the SiC MOSFET device, and to determine the second current change rate and the second voltage change rate of the SiC MOSFET device under the drive protection circuit based on the temperature characteristics and the degradation information. The calculation module is used to perform an intersection operation on the first current change rate and the second current change rate to obtain the target current change rate, and to perform an intersection operation on the first voltage change rate and the second voltage change rate to obtain the target voltage change rate. The evaluation module is used to evaluate the high-frequency dynamic safe operating area of ​​the SiC MOSFET device based on the target current change rate and the target voltage change rate, respectively.

[0012] Thirdly, this application provides an electronic device, comprising: at least one memory for storing a program; and at least one processor for executing the program stored in the memory, wherein when the program stored in the memory is executed, the processor is configured to execute the method described in the first aspect or any possible implementation thereof.

[0013] Fourthly, this application provides a computer-readable storage medium storing a computer program that, when run on a processor, causes the processor to perform the method described in the first aspect or any possible implementation thereof.

[0014] Fifthly, this application provides a computer program product that, when run on a processor, causes the processor to perform the method described in the first aspect or any possible implementation thereof.

[0015] It is understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.

[0016] Overall, the technical solutions conceived in this application have the following beneficial effects compared with the prior art: (1) This application considers that the secondary problems of switching transients (oscillation spikes and crosstalk) of SiC MOSFET devices are caused by the large current and voltage change rates generated during high-speed switching, which couple with parasitic parameters in the SiC MOSFET device and circuit to form interference voltage and interference current. Therefore, the switching speed is characterized by the current and voltage change rates to achieve effective evaluation of voltage and current overshoot and oscillation during switching transients. At the same time, in active gate control, the ringing can be suppressed and the switching speed can be maximized by real-time control of this characteristic quantity, so as to give full play to the high-frequency characteristics of SiC MOSFET devices.

[0017] (2) In calculating the first current change rate and the first voltage change rate that cause the failure of the SiC MOSFET device, this application identifies multiple factors that cause the failure of the SiC MOSFET device, and then performs calculations based on the corresponding parameters. In addition, since temperature and the degree of device degradation affect the current change rate and voltage change rate of the SiC MOSFET device under the drive protection circuit, the second current change rate and the second voltage change rate of the SiC MOSFET device under the drive protection circuit are determined based on temperature characteristics and degradation information, which enables dynamic evaluation of the high-frequency performance of the SiC MOSFET device over a long lifespan.

[0018] In summary, this application obtains the failure modes of a SiC MOSFET device and determines the first current change rate and the first voltage change rate that cause the failure of the SiC MOSFET device based on the failure modes; obtains the second current change rate and the second voltage change rate of the SiC MOSFET device under the drive protection circuit, and determines the target current change rate and the target voltage change rate based on the first current change rate and the second current change rate; determines the target temperature change characteristic information based on the real-time current change rate and the real-time voltage change rate of the SiC MOSFET device as a function of temperature, and determines the target degradation characteristic information based on the real-time current change rate and the real-time voltage change rate of the SiC MOSFET device under different degradation levels; and evaluates the high-frequency dynamic safe operating area of ​​the SiC MOSFET device based on the target current change rate, the target voltage change rate, the target temperature change characteristic information, and the target degradation characteristic information. By taking into account the root causes of secondary problems caused by switching transients in SiC MOSFET devices, the target current change rate and target voltage change rate are used to characterize the switching rate, thereby enabling effective assessment of voltage and current overshoot and oscillations during switching transients. Furthermore, the target temperature change characteristic information and target degradation characteristic information are combined to assess the safe operating area, thus effectively improving the accuracy of assessing the dynamic safe operating area during high-frequency operation. Attached Figure Description

[0019] Figure 1 This is one of the flowcharts illustrating the evaluation method for a high-frequency dynamic security working area provided in the embodiments of this application; Figure 2 This is a trend diagram of the high-frequency operation dynamic safe operating area as a function of stray inductance, provided in the embodiments of this application. Figure 3 This is a schematic diagram illustrating the relationship between gate resistance and current change rate provided in an embodiment of this application; Figure 4 This is a schematic diagram illustrating the relationship between gate resistance and voltage change rate provided in an embodiment of this application; Figure 5 This is a trend graph showing the change of the high-frequency dynamic safe operating area with temperature in terms of current dimension, as provided in the embodiments of this application. Figure 6 This is a trend graph showing the change of the high-frequency dynamic safe operating area in terms of current dimension with the degree of degradation, as provided in the embodiments of this application. Figure 7 This is a trend graph showing the change of the high-frequency operating dynamic safe working area with temperature in terms of voltage dimension, as provided in the embodiments of this application. Figure 8 This is a trend graph showing the change of the high-frequency operating dynamic safe working area with the degree of degradation in the voltage dimension, as provided in the embodiments of this application. Figure 9 This is a circuit diagram of the target sampling circuit provided in the embodiments of this application; Figure 10 This is a schematic diagram of the dynamic safe operating region of a SiC MOSFET device at high frequency, as evaluated based on the target current change rate, provided in an embodiment of this application. Figure 11 This is a schematic diagram of the high-frequency operating dynamic safe operating region of a SiC MOSFET device, as evaluated based on the target voltage change rate, provided in an embodiment of this application. Figure 12 This is a schematic diagram of the module structure of the evaluation device for the high-frequency operating dynamic safety working area provided in the embodiments of this application; Figure 13 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0021] In this article, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The symbol " / " in this article indicates that the related objects are in an "or" relationship; for example, A / B means A or B.

[0022] The terms "first" and "second," etc., used in the specification and claims herein are used to distinguish different objects, not to describe a specific order of objects. For example, "first response message" and "second response message," etc., are used to distinguish different response messages, not to describe a specific order of response messages.

[0023] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0024] Based on this, embodiments of this application provide an evaluation method for a high-frequency operating dynamic security workspace, referring to... Figure 1 , Figure 1This is one of the flowcharts illustrating the evaluation method for a high-frequency operating dynamic security working area provided in this application embodiment. In this embodiment, the evaluation method for a high-frequency operating dynamic security working area includes steps S10 to S40: Step S10: Obtain the first current change rate and the first voltage change rate that cause the SiC MOSFET device to fail.

[0025] It should be noted that the SiC MOSFET device refers to the device used to evaluate the dynamic safe operating area during high-frequency operation. In this embodiment, considering that the secondary problems of SiC MOSFET switching transients (oscillation spikes and crosstalk) are caused by the large current and voltage change rates generated during high-speed switching coupling with parasitic parameters existing in the SiC MOSFET device and circuit, resulting in interference voltage and interference current, the switching rate is characterized by the current and voltage change rates to achieve effective evaluation of voltage and current overshoot and oscillation during switching transients. Furthermore, in active gate control, real-time control of this characteristic quantity can suppress ringing, maximize switching speed, and fully utilize the high-frequency characteristics of the SiC MOSFET device.

[0026] It should be understood that for SiC MOSFET devices, the causes of failure differ under different parameters. For example, under high current change rate, SiC MOSFET devices may fail due to drain-source breakdown or reverse recovery of the body diode. Under high voltage change rate, SiC MOSFET devices may fail due to parasitic NPN conduction or bridge arm punch-through caused by crosstalk in the half-bridge circuit. The first current change rate refers to the maximum current change rate at which SiC MOSFET devices fail under high current change rate. Similarly, the first voltage change rate refers to the maximum voltage change rate at which SiC MOSFET devices fail under high voltage change rate.

[0027] Further, the step of obtaining the first current change rate leading to the failure of the SiC MOSFET device includes: obtaining the loop stray inductance when the SiC MOSFET device fails due to drain-source breakdown under a high current change rate; calculating the first current change rate leading to the failure of the SiC MOSFET device based on the maximum voltage that the drain and source can withstand, the loop stray inductance, and the bus voltage; obtaining the reverse recovery data of the body diode when the SiC MOSFET device fails due to reverse recovery of the body diode under a high current change rate; and determining the first current change rate leading to the failure of the SiC MOSFET device based on the reverse recovery data of the body diode.

[0028] It should be understood that for SiC MOSFET devices, during the turn-off transient, the rapid high rate of current change couples with stray parameters in the power circuit, superimposing the drain-source voltage and thus forming a voltage spike at the drain-source. If this voltage spike exceeds the maximum withstand voltage of the SiC MOSFET device, it may cause the SiC MOSFET device to fail. Therefore, the stray inductance of the circuit can be obtained at the moment of failure, and the first rate of current change that leads to the failure of the SiC MOSFET device can be calculated by combining the maximum voltage that the drain and source can withstand and the bus voltage. Specifically: .

[0029] in, This indicates the maximum voltage that the drain and source terminals can withstand. Indicates the stray inductance of the circuit. This indicates the bus voltage.

[0030] It should be noted that the reference Figure 2 , Figure 2 This is a trend graph showing the dynamic safe operating area at high frequency as a function of stray inductance, specifically with a drain-source breakdown voltage of 1700V. L loop =1nH、 Lloop =2nH、 Lloop Taking 3nH as an example, the stray inductance in the circuit is explained. L loop As the voltage gradually increases from 1nH to 2nH to 3nH, the maximum allowable rate of change of current in a SiC MOSFET device decreases gradually for the same breakdown voltage.

[0031] Understandably, another factor affecting the rate of change of current is the gate resistance. Different gate resistances cause changes in the rate of rise of the gate voltage, thus affecting the rate of change of current. Under the driving action, when the rate of change of current is at its maximum, the gate resistance at the driving end is 0Ω. Analysis shows that the gate resistance and the rate of change of current exhibit an exponential relationship (e). (Reference) Figure 3 , Figure 3 This diagram illustrates the relationship between gate resistance and the rate of change of current. Specifically, when the gate resistance is 0Ω, there is still a small resistance inside the gate. Analysis of the curve shows that the rate of change of current reaches its maximum value (maximum rate of change of current) when the external resistance of the gate is 0Ω. (Reference) Figure 4 , Figure 4The diagram illustrates the relationship between gate resistance and voltage change rate. Specifically, the green line represents the maximum voltage change rate when the external gate resistance is 0Ω, the blue line represents the maximum allowable voltage change rate when the target threshold voltage is 3.5V, and the orange line represents the maximum allowable gate resistance of the system. At this point, the switching speed of the device under evaluation slows down, the switching losses increase, and it is not conducive to utilizing the high-frequency characteristics of the device under evaluation.

[0032] It should be understood that, for SiC MOSFET devices, the reverse recovery of the body diode can also cause the SiC MOSFET device to fail. In this case, the reverse recovery data of the body diode can be obtained, and the first current change rate that causes the SiC MOSFET device to fail can be further determined.

[0033] Further, the step of obtaining the first voltage change rate that causes the SiC MOSFET device to fail includes: when the SiC MOSFET device fails due to parasitic NPN conduction under a high voltage change rate, obtaining the junction capacitance formed in the drain base region; calculating the first voltage change rate that causes the SiC MOSFET device to fail based on the junction capacitance formed in the drain base region, the PN junction built-in potential, and the base region resistance; when the SiC MOSFET device fails due to bridge arm punch-through caused by crosstalk in the half-bridge circuit under a high voltage change rate, obtaining the target threshold voltage; and calculating the first voltage change rate that causes the SiC MOSFET device to fail based on the target threshold voltage, the gate resistance, and the gate-drain capacitance.

[0034] It should be noted that for SiC MOSFET devices, when operating at high frequencies, their drains undergo rapid changes, resulting in an extremely high voltage change rate. This high voltage change rate can cause the SiC MOSFET device to fail due to parasitic NPN conduction or crosstalk in the half-bridge circuit causing bridge arm punch-through. Specifically, for SiC MOSFET devices containing parasitic NPN bipolar transistors, when a high voltage change rate exists at the drain, current is generated through the junction capacitance formed in the drain-base region. When this current passes through the P-type base region resistor, the voltage drop across the P-type base region resistor causes the parasitic NPN bipolar transistor to be forward biased at the emitter-base junction. When the voltage drop equals the built-in potential of the target junction, current injection begins within the junction. At this point, the first voltage change rate leading to SiC MOSFET device failure can be calculated. Specifically: .

[0035] in, This represents the built-in potential of the PN junction. This represents the junction capacitance formed in the drain-base region. This represents the base region resistance.

[0036] On the other hand, for SiC MOSFET devices, when a high voltage change rate acts on the drain, a displacement current is generated on the parasitic capacitance. When this displacement current flows through the gate circuit, a voltage is generated at the gate-source terminals. If the generated voltage exceeds the target threshold voltage, the SiC MOSFET device will turn on falsely, causing the SiC MOSFET device to fail. In this case, the first voltage change rate that causes the SiC MOSFET device to fail can be calculated. Specifically: .

[0037] in, Indicates the target threshold voltage. Indicates gate resistance. This represents the gate-drain capacitance.

[0038] Step S20: Obtain the temperature characteristics and degradation information of the SiC MOSFET device, and determine the second current change rate and the second voltage change rate of the SiC MOSFET device under the drive protection circuit based on the temperature characteristics and the degradation information.

[0039] It is understood that the second current change rate refers to the maximum current change rate when the drive protection circuit is connected and the SiC MOSFET device is affected by temperature and degradation. Similarly, the second voltage change rate refers to the maximum voltage change rate when the drive protection circuit is connected and the SiC MOSFET device is affected by temperature and degradation. The second current change rate is less than the first current change rate, and the second voltage change rate is less than the first voltage change rate.

[0040] Further, step S20 includes: acquiring the temperature characteristics and degradation information of the SiC MOSFET device; determining the current change rate and voltage change rate of the SiC MOSFET device at different temperatures based on the temperature characteristics; determining the current change rate and voltage change rate of the SiC MOSFET device at different degradation levels based on the degradation information; when a drive protection circuit is detected to be connected to the SiC MOSFET device, determining a second current change rate based on the current change rate and current change rate of the SiC MOSFET device at different temperatures and at different degradation levels, and determining a second voltage change rate based on the voltage change rate and voltage change rate of the SiC MOSFET device at different temperatures and at different degradation levels based on the temperature characteristics.

[0041] It should be understood that the current and voltage change rates under the drive protection circuit are affected by the temperature and degradation of the SiC MOSFET device, thus affecting the dynamic safe operating area at high frequencies. Therefore, when calculating the second current and second voltage change rates of the SiC MOSFET device under the drive protection circuit, it is necessary to incorporate the temperature characteristics and degradation information of the SiC MOSFET device. At this time, the current and voltage change rates of the SiC MOSFET device at different temperatures and the current and voltage change rates of the SiC MOSFET device at different degradation levels can be determined separately. Then, the second current change rate is determined based on the current and voltage change rates of the SiC MOSFET device at different temperatures and the current and voltage change rates at different degradation levels, i.e., the current change rate taking temperature and degradation into account. The second voltage change rate is determined based on the voltage change rates of the SiC MOSFET device at different temperatures and the voltage and voltage change rates at different degradation levels, i.e., the voltage change rate taking temperature and degradation into account.

[0042] It should be noted that the reference Figure 5 , Figure 5 This is a trend chart of the high-frequency dynamic safe operating region as a function of temperature, specifically: the high-frequency dynamic safe operating region in the current dimension consists of three lines. The green line represents the maximum current change rate when the external gate resistance is 0Ω; the blue line represents the maximum allowable drain-source voltage for the SiC MOSFET device under different stray inductances; and the orange line represents the maximum allowable drain-source voltage. As can be seen from the blue line, when the bus voltage... V dc When approaching the maximum allowable voltage of a SiC MOSFET device, the margin of the current change rate is reached, which significantly reduces the current-carrying capacity of the SiC MOSFET device, thus wasting its current-carrying characteristics. As temperature increases, the current change rate increases with temperature, causing the maximum value of the current change rate to rise, but the corresponding bus voltage also decreases. Therefore, with increasing temperature, the safe operating area corresponding to the current change rate increases. (Reference) Figure 6 , Figure 6 This is a trend graph showing the change of the dynamic safe operating area for high-frequency operation with the degree of degradation in the current dimension. Specifically, as the degree of gate degradation of the SiC MOSFET device increases, the rate of change of current gradually decreases, which in turn causes the dynamic safe operating area for high-frequency operation to shrink. For example, when the degree of gate degradation is A, the dynamic safe operating area for high-frequency operation is a1, and when the degree of gate degradation is B, the dynamic safe operating area for high-frequency operation is b1, and B > A, b1 < a1.

[0043] It should be understood that, reference Figure 7 , Figure 7This is a trend graph showing the dynamic safe operating range for high-frequency operation as a function of temperature, specifically: as temperature increases, the target threshold voltage decreases, causing the maximum rate of voltage change to decrease, which in turn reduces the dynamic safe operating range for high-frequency operation. For example, at temperature C, the dynamic safe operating range for high-frequency operation is a2, and at temperature D, it is b2, where D > C and b2 < a2. (Reference) Figure 8 , Figure 8 This is a trend diagram showing the change of the high-frequency operating dynamic safe working area with the degree of degradation in the voltage dimension. Specifically, as the degree of gate degradation of the SiC MOSFET device increases, its target threshold voltage increases, which also increases the maximum allowable voltage change rate. Therefore, the high-frequency operating dynamic safe working area shows an expanding trend. For example, when the gate degradation degree is E, the high-frequency operating dynamic safe working area is a3, and when the gate degradation degree is F, the high-frequency operating dynamic safe working area is b3, and F > E, b3 > a3.

[0044] Further, the step of determining a second current change rate based on the current change rate of the SiC MOSFET device at different temperatures and the current change rate at different degradation levels when the drive protection circuit is detected to be connected to the SiC MOSFET device, and determining a second voltage change rate based on the voltage change rate of the SiC MOSFET device at different temperatures and the voltage change rate at different degradation levels when the drive protection circuit is detected to be connected to the SiC MOSFET device, includes: detecting the current temperature and current degradation level of the SiC MOSFET device when the drive protection circuit is detected to be connected to the SiC MOSFET device; determining a current change rate corresponding to the current temperature based on the current change rate of the SiC MOSFET device at different temperatures, and determining a current change rate corresponding to the current degradation level based on the current change rate of the SiC MOSFET device at different degradation levels; determining a second current change rate based on the current change rate corresponding to the current temperature and the current change rate corresponding to the current degradation level; determining a voltage change rate corresponding to the current temperature based on the voltage change rate of the SiC MOSFET device at different temperatures, and determining a second voltage change rate based on the voltage change rate of the SiC MOSFET device at different degradation levels when the drive protection circuit is detected to be connected to the SiC MOSFET device, including: detecting the current temperature and current degradation level of the SiC MOSFET device when the drive protection circuit is detected to be connected to the SiC MOSFET device; determining a second current change rate based on the current change rate corresponding to the current temperature and the current degradation level when the drive protection circuit is detected to be connected to the SiC MOSFET device; determining a second voltage ... The voltage change rate of the MOSFET device at different degradation levels is used to determine the voltage change rate corresponding to the current degradation level; a second voltage change rate is determined based on the voltage change rate corresponding to the current temperature and the voltage change rate corresponding to the current degradation level.

[0045] It should be noted that, in order to effectively improve the accuracy of determining the second current change rate and the second voltage change rate, this embodiment also detects the current temperature and current degradation level of the SiC MOSFET device. On the one hand, regarding the current change rate, the current change rate corresponding to the current temperature can be looked up based on the current change rate of the SiC MOSFET device at different temperatures. After analyzing the expression for the current change rate, the partial derivative of the expression for the current change rate can be calculated, and based on the derivative result, the target threshold voltage can be determined. and electron mobility The current temperature coefficients presented are all negative, meaning they decrease as temperature increases. Therefore, it can be determined that the current change rate increases with increasing temperature. Based on the current change rate of the SiC MOSFET device at different degradation levels, the current change rate corresponding to the current degradation level is determined. Then, combining the two current change rates mentioned above, a second current change rate is determined.

[0046] On the other hand, regarding the voltage change rate, the voltage change rate corresponding to the current temperature can be determined based on the voltage change rate of the SiC MOSFET device at different temperatures. For a SiC MOSFET device, as its gate degrades, the target threshold voltage of the SiC MOSFET device gradually increases, and the voltage change rate gradually decreases. Conversely, as its gate degrades, the target threshold voltage of the SiC MOSFET device gradually increases, thus increasing the maximum allowable voltage change rate. Furthermore, the voltage change rate corresponding to the current degradation level can be determined based on the voltage change rate of the SiC MOSFET device at different degradation levels. Combining these two voltage change rates, a second voltage change rate is determined.

[0047] It should be understood that, reference Figure 9 , Figure 9 The circuit diagram for the target sampling circuit is as follows: The target sampling circuit includes a main circuit, a voltage change rate sampling circuit (upper green part), and a current change rate sampling circuit (lower green part). The core of the current change rate sampling circuit is based on a common-source inductor. Specifically, it first collects the voltage change across the common-source inductor, and then uses the linear relationship between the voltage change and the current change rate to directly calculate the current change rate. The whole process relies on the inherent characteristics of the common-source inductor and the basic principle of electromagnetic induction. The voltage change rate sampling circuit includes a high-voltage capacitor and a resistor. The main mechanism is that when a high voltage change rate acts on the high-voltage capacitor, a displacement current is generated across the high-voltage capacitor. When this displacement current flows through the resistor, a voltage is generated. Measuring this voltage yields the voltage change rate.

[0048] Step S30: Perform an intersection operation on the first current change rate and the second current change rate to obtain the target current change rate, and perform an intersection operation on the first voltage change rate and the second voltage change rate to obtain the target voltage change rate.

[0049] It should be understood that after determining the second current change rate and the second voltage change rate, the optimal current change rate (i.e., the target current change rate) and the optimal voltage change rate (i.e., the target current change rate) can be determined by taking the intersection of the first current change rate and the first voltage change rate, which lead to the failure of the SiC MOSFET device. Specifically, this involves taking the intersection of the first current change rate and the second current change rate, and taking the intersection of the first voltage change rate and the second voltage change rate, ultimately obtaining the target current change rate and the target voltage change rate. Through this intersection calculation method, safe, reliable, and executable current change rates and voltage change rates are determined for the SiC MOSFET device.

[0050] Step S40: Evaluate the high-frequency dynamic safe operating region of the SiCMOSFET device based on the target current change rate and the target voltage change rate, respectively.

[0051] It should be noted that after obtaining the target current change rate and the target voltage change rate, the high-frequency dynamic safe operating region of the SiC MOSFET device can be evaluated separately. A schematic diagram of the high-frequency dynamic safe operating region of the SiC MOSFET device evaluated based on the target current change rate can be found here. Figure 10 Specifically, the green area represents the high-frequency dynamic safe operating region of a SiC MOSFET device, as assessed based on the target voltage change rate. (See the schematic diagram for details.) Figure 11 Specifically, the green area.

[0052] Further, step S40 includes: evaluating the high-frequency dynamic safe operating region of the SiC MOSFET device in the current dimension based on the target current change rate; and evaluating the high-frequency dynamic safe operating region of the SiC MOSFET device in the voltage dimension based on the target voltage change rate.

[0053] It is understood that, in this embodiment, the high-frequency dynamic safe operating region of the SiC MOSFET device is divided into a high-frequency dynamic safe operating region in the current dimension and a high-frequency dynamic safe operating region in the voltage dimension. After obtaining the target current change rate and the target voltage change rate, the high-frequency dynamic safe operating region is evaluated from the current dimension based on the target current change rate, which is the high-frequency dynamic safe operating region of the SiC MOSFET device in the current dimension. The high-frequency dynamic safe operating region is evaluated from the voltage dimension based on the target voltage change rate, which is the high-frequency dynamic safe operating region of the SiC MOSFET device in the voltage dimension.

[0054] This embodiment obtains the first current change rate and the first voltage change rate that cause the SiC MOSFET device to fail; it obtains the temperature characteristics and degradation information of the SiC MOSFET device, and determines the second current change rate and the second voltage change rate of the SiC MOSFET device under the drive protection circuit based on the temperature characteristics and the degradation information; it performs an intersection operation on the first current change rate and the second current change rate to obtain the target current change rate, and performs an intersection operation on the first voltage change rate and the second voltage change rate to obtain the target voltage change rate; it evaluates the high-frequency dynamic safe operating area of ​​the SiC MOSFET device based on the target current change rate and the target voltage change rate. By considering the root causes of secondary problems of switching transients in SiC MOSFET devices, the current change rate and voltage change rate are selected to characterize the switching rate to achieve an effective evaluation of voltage and current overshoot and oscillation during switching transients. Combined with temperature characteristics and degradation information, the evaluation of the safe operating area is performed, thereby effectively improving the accuracy of evaluating the high-frequency dynamic safe operating area.

[0055] The evaluation apparatus for the high-frequency dynamic safety working area provided in this application is described below. The evaluation apparatus for the high-frequency dynamic safety working area described below can be referred to in conjunction with the evaluation method for the high-frequency dynamic safety working area described above. Please refer to... Figure 12 , Figure 12 This is a schematic diagram of the module structure of the evaluation device for the high-frequency dynamic safety working area provided in this application embodiment, including: The acquisition module T10 is used to acquire the failure mode of the SiC MOSFET device and determine the first current change rate and the first voltage change rate that cause the failure of the SiC MOSFET device based on the failure mode.

[0056] The acquisition module T10 is further configured to acquire the second current change rate and the second voltage change rate of the SiC MOSFET device under the drive protection circuit, and determine the target current change rate based on the first current change rate and the second current change rate, and determine the target voltage change rate based on the first voltage change rate and the second voltage change rate.

[0057] The determination module T20 is used to determine the target temperature change characteristic information based on the real-time current change rate and real-time voltage change rate of the SiC MOSFET device with temperature, and to determine the target degradation characteristic information based on the real-time current change rate and real-time voltage change rate of the SiC MOSFET device under different degradation levels.

[0058] Evaluation module T30 is used to evaluate the high-frequency dynamic safe operating area of ​​the SiC MOSFET device based on the target current change rate, the target voltage change rate, the target temperature change characteristic information, and the target degradation characteristic information.

[0059] This embodiment acquires the failure modes of a SiC MOSFET device and determines the first current change rate and the first voltage change rate that cause the SiC MOSFET device to fail based on the failure modes; acquires the second current change rate and the second voltage change rate of the SiC MOSFET device under the drive protection circuit, and determines the target current change rate and the target voltage change rate based on the first current change rate and the second current change rate; determines the target temperature change characteristic information based on the real-time current change rate and the real-time voltage change rate of the SiC MOSFET device as a function of temperature, and determines the target degradation characteristic information based on the real-time current change rate and the real-time voltage change rate of the SiC MOSFET device under different degradation levels; and evaluates the high-frequency dynamic safe operating area of ​​the SiC MOSFET device based on the target current change rate, the target voltage change rate, the target temperature change characteristic information, and the target degradation characteristic information. By taking into account the root causes of secondary problems caused by switching transients in SiC MOSFET devices, the target current change rate and target voltage change rate are used to characterize the switching rate, thereby enabling effective assessment of voltage and current overshoot and oscillations during switching transients. Furthermore, the target temperature change characteristic information and target degradation characteristic information are combined to assess the safe operating area, thus effectively improving the accuracy of assessing the dynamic safe operating area during high-frequency operation.

[0060] It is understood that the detailed functional implementation of each of the above modules can be found in the description of the aforementioned method embodiments, and will not be repeated here.

[0061] It should be understood that the above-described device is used to execute the methods in the above embodiments. The implementation principle and technical effect of the corresponding program modules in the device are similar to those described in the above methods. The working process of the device can be referred to the corresponding process in the above methods, and will not be repeated here.

[0062] Based on the methods in the above embodiments, this application provides an electronic device, please refer to... Figure 13 , Figure 13 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application.

[0063] It should be noted that the system may include: a processor 10, a communications interface 20, a memory 30, and a communication bus 40. The processor 10, communications interface 20, and memory 30 communicate with each other via the communication bus 40. The processor 10 can invoke logical instructions stored in the memory 30 to execute the methods described in the above embodiments.

[0064] Furthermore, the logical instructions in the aforementioned memory 30 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application.

[0065] Based on the methods in the above embodiments, this application provides a computer-readable storage medium storing a computer program that, when run on a processor, causes the processor to execute the methods in the above embodiments.

[0066] Based on the methods in the above embodiments, this application provides a computer program product that, when run on a processor, causes the processor to execute the methods in the above embodiments.

[0067] It is understood that the processor in the embodiments of this application can be a central processing unit, or other general-purpose processors, digital signal processors, application-specific integrated circuits, field-programmable gate arrays, or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0068] The method steps in this application embodiment can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor.

[0069] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. Those skilled in the art will readily understand that the above descriptions are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for evaluating the dynamic safe operating area during high-frequency operation, characterized in that, include: Obtain the first current change rate and the first voltage change rate that lead to the failure of the SiC MOSFET device; The temperature characteristics and degradation information of the SiC MOSFET device are obtained, and the second current change rate and the second voltage change rate of the SiC MOSFET device under the drive protection circuit are determined according to the temperature characteristics and the degradation information, respectively. The first current change rate and the second current change rate are intersected to obtain the target current change rate, and the first voltage change rate and the second voltage change rate are intersected to obtain the target voltage change rate. The high-frequency operating dynamic safe operating region of the SiC MOSFET device is evaluated based on the target current change rate and the target voltage change rate, respectively.

2. The method as described in claim 1, characterized in that, The steps of acquiring the temperature characteristics and degradation information of the SiC MOSFET device, and determining the second current change rate and the second voltage change rate of the SiC MOSFET device under the drive protection circuit based on the temperature characteristics and the degradation information, respectively, include: To obtain temperature characteristics and degradation information of SiC MOSFET devices; The current and voltage change rates of the SiC MOSFET device at different temperatures were determined based on the aforementioned temperature characteristics. Based on the degradation information, determine the current and voltage change rates of the SiC MOSFET device under different degrees of degradation; When the drive protection circuit is detected to be connected to the SiC MOSFET device, a second current change rate is determined based on the current change rate of the SiC MOSFET device at different temperatures and the current change rate at different degradation levels, and a second voltage change rate is determined based on the voltage change rate of the SiC MOSFET device at different temperatures and the voltage change rate at different degradation levels.

3. The method as described in claim 2, characterized in that, The steps of determining a second current change rate based on the current change rate of the SiC MOSFET device at different temperatures and at different degradation levels when the drive protection circuit is detected to be connected to the SiC MOSFET device, and determining a second voltage change rate based on the voltage change rate of the SiC MOSFET device at different temperatures and at different degradation levels, and determining a second voltage change rate based on the temperature characteristics, include: When the drive protection circuit is detected to be connected to the SiC MOSFET device, the current temperature and current degradation level of the SiC MOSFET device are detected. The current change rate corresponding to the current temperature is determined based on the current change rate of the SiC MOSFET device at different temperatures, and the current change rate corresponding to the current degradation level is determined based on the current change rate of the SiC MOSFET device at different degradation levels. The second current change rate is determined based on the current change rate corresponding to the current temperature and the current change rate corresponding to the current degree of degradation; The voltage change rate corresponding to the current temperature is determined based on the voltage change rate of the SiC MOSFET device at different temperatures, and the voltage change rate corresponding to the current degradation level is determined based on the voltage change rate of the SiC MOSFET device at different degradation levels. The second voltage change rate is determined based on the voltage change rate corresponding to the current temperature and the voltage change rate corresponding to the current degree of degradation.

4. The method as described in claim 1, characterized in that, The step of obtaining the first current change rate that leads to the failure of the SiC MOSFET device includes: When a SiC MOSFET device fails due to drain-source breakdown under high current change rate, the stray inductance of the circuit is obtained. The first current change rate that causes the SiCMOSFET device to fail is calculated based on the maximum voltage that the drain and source can withstand, the stray inductance of the circuit, and the bus voltage. When a SiC MOSFET device fails due to reverse recovery of the body diode under high current change rate, the reverse recovery data of the body diode is obtained. The first current change rate that causes the failure of the SiC MOSFET device is determined based on the reverse recovery data of the body diode.

5. The method as described in claim 1, characterized in that, The step of obtaining the first voltage change rate that causes the SiC MOSFET device to fail includes: When a SiC MOSFET device fails due to parasitic NPN conduction under high voltage change rate, the junction capacitance formed in the drain base region is obtained. The first voltage change rate that causes the failure of the SiCMOSFET device is calculated based on the junction capacitance formed in the drain base region, the PN junction built-in potential, and the base region resistance. When SiC MOSFET devices fail due to bridge arm punch-through caused by crosstalk in the half-bridge circuit under high voltage change rate, the target threshold voltage is obtained. The first voltage change rate that causes the SiC MOSFET device to fail is calculated based on the target threshold voltage, gate resistance, and gate-drain capacitance.

6. The method according to any one of claims 1 to 5, characterized in that, The step of evaluating the high-frequency dynamic safe operating region of the SiC MOSFET device based on the target current change rate and the target voltage change rate includes: The dynamic safe operating region of the SiC MOSFET device in the current dimension is evaluated based on the target current change rate. The target voltage change rate is used to evaluate the dynamic safe operating region of the SiC MOSFET device at high frequencies in the voltage dimension.

7. An evaluation device for a high-frequency operating dynamic safety working area, characterized in that, include: The acquisition module is used to acquire the first current change rate and the first voltage change rate that cause the SiC MOSFET device to fail; The acquisition module is also used to acquire the temperature characteristics and degradation information of the SiC MOSFET device, and to determine the second current change rate and the second voltage change rate of the SiC MOSFET device under the drive protection circuit based on the temperature characteristics and the degradation information. The calculation module is used to perform an intersection operation on the first current change rate and the second current change rate to obtain the target current change rate, and to perform an intersection operation on the first voltage change rate and the second voltage change rate to obtain the target voltage change rate. The evaluation module is used to evaluate the high-frequency dynamic safe operating area of ​​the SiCMOSFET device based on the target current change rate and the target voltage change rate, respectively.

8. An electronic device, characterized in that, include: At least one memory for storing computer programs; At least one processor is configured to execute a program stored in the memory, wherein when the program stored in the memory is executed, the processor is configured to perform the method as described in any one of claims 1-6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is run on the processor, it causes the processor to perform the method as described in any one of claims 1-6.

10. A computer program product, characterized in that, When the computer program product is run on a processor, the processor causes the processor to perform the method as described in any one of claims 1-6.

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