A method, apparatus, device, storage medium and program product for overcurrent protection

Abstract

This application discloses an overcurrent protection method, apparatus, device, storage medium, and program product. The overcurrent protection method is applied to a power electronic converter, which includes at least an inductor. The method includes: acquiring the current signal of the inductor at the current sampling moment, processing the current signal to generate a rate of change parameter of the inductor at the current sampling moment; determining a current limiting threshold at the current sampling moment based on a preset expected protection current peak value, the rate of change parameter, and a preset delay compensation coefficient; generating a protection trigger signal when the instantaneous value of the current signal at the current sampling moment exceeds the current limiting threshold, and performing a turn-off operation of the switching transistor in the circuit containing the inductor based on the protection trigger signal. According to the embodiments of this application, reliable protection of the device can be achieved.

Description

Technical Field

[0001] This application belongs to the field of device protection technology, and in particular relates to an overcurrent protection method, device, equipment, storage medium and program product. Background Technology

[0002] In power electronic conversion devices such as inverters and energy storage converters, overcurrent protection is a critical aspect of ensuring the safe operation of switching transistors and power devices. Existing technologies typically employ fixed-threshold overcurrent protection schemes. This involves sampling the real-time current using a current sensor, comparing it to a preset reference value via a comparator, and then executing current-limiting measures by a microcontroller if an overcurrent is detected. However, due to inherent transmission delays in the current sensor, signal processing link, and drive circuit, there is a fixed delay period between current sampling and the actual turn-off of the switching transistor. During this delay, the inductor current continues to rise, causing the peak current at actual turn-off to exceed the preset protection threshold. Furthermore, the steeper the current rise, the more severe the peak overshoot. Especially under sudden short-circuit or heavy-load sudden changes, the delayed response can easily lead to overcurrent damage to power devices, failing to achieve reliable device protection. Summary of the Invention

[0003] This application provides an overcurrent protection method, apparatus, device, storage medium, and program product, which achieves reliable protection for the device.

[0004] In a first aspect, embodiments of this application provide an overcurrent protection method applied to a power electronic conversion device, the power electronic conversion device including at least an inductive element, comprising: The current signal of the inductor at the current sampling time is acquired and processed to generate the rate of change parameter of the inductor at the current sampling time. The current signal is used to characterize the operating state of the inductor. Based on the preset expected protection current peak value, rate of change parameter and preset delay compensation coefficient, the current limiting threshold corresponding to the current sampling time is determined. If the instantaneous value of the current signal at the current sampling time exceeds the current limiting threshold, a protection trigger signal is generated, and the switching transistor in the circuit containing the inductor is turned off based on the protection trigger signal.

[0005] In one implementation, determining the current limiting threshold corresponding to the current sampling time includes: Based on the rate of change parameter and delay compensation coefficient corresponding to the current sampling time, the predicted current increment is determined. The predicted current increment is used to characterize the expected rise of the current within the inherent delay time. The difference between the predicted current increment and the expected protection current peak is calculated to generate the current limiting threshold corresponding to the current sampling time.

[0006] In one implementation, the current signal of the inductor at the current sampling time is acquired, and the current signal is processed to generate a rate of change parameter of the inductor at the current sampling time, including: Based on the current signal at the current sampling time and the current signal at the previous sampling time, determine the deviation component at the current sampling time. Based on the deviation component and the sampling time interval, a rate of change parameter is generated, where the sampling time interval is the time difference between the current sampling time and the previous sampling time.

[0007] In one implementation, generating the rate of change parameter of the inductor element at the current sampling time includes: Differentiate the current signal to generate an analog electrical signal; Analog-to-digital conversion is performed on the analog electrical signal to obtain the rate of change parameter.

[0008] In one implementation, after generating the current limiting threshold corresponding to the current sampling time, the method further includes: If the rate of change parameter is less than the first rate of change threshold, the current limiting threshold is determined to be the expected protection current peak value; If the rate of change parameter is greater than or equal to the second rate of change threshold, the current limiting threshold is determined to be the preset minimum allowable current limiting value, wherein the first rate of change threshold is less than the second rate of change threshold.

[0009] In one implementation, after performing a turn-off operation on the switch in the circuit containing the inductor based on a protection trigger signal, the method further includes: If the instantaneous current value at each sampling time within a preset time period after the inductor is turned off is less than the preset recovery threshold, the overcurrent fault status flag corresponding to the inductor is reset. Based on the overcurrent fault status flag after reset, the enable signal of the corresponding switch of the inductor is output to enable the inductor to resume current transmission.

[0010] Secondly, embodiments of this application provide an overcurrent protection device, including: The sampling module is used to acquire the current signal corresponding to the inductive element in the power electronic conversion device at the current sampling time. The signal processing module is used to process the current signal, generate the rate of change parameter of the inductor at the current sampling time, and determine the current limiting threshold at the current sampling time based on the preset expected protection current peak, the rate of change parameter and the preset delay compensation coefficient. The current signal is used to characterize the operating state of the inductor. The execution module is used to generate a protection trigger signal when the instantaneous value of the current signal at the current sampling time exceeds the current limiting threshold, and to perform the turn-off operation of the switching transistor in the circuit where the inductor is located based on the protection trigger signal.

[0011] Thirdly, embodiments of this application provide an electronic device, the device comprising: Processor and memory storing programs or instructions; The first aspect of overcurrent protection can be implemented when the processor executes a program or instruction.

[0012] Fourthly, embodiments of this application provide a computer storage medium storing a program or instructions, which, when executed by a processor, can implement the overcurrent protection method of the first aspect.

[0013] Fifthly, embodiments of this application provide a computer program product in which instructions, when executed by the processor of an electronic device, cause the electronic device to perform the overcurrent protection method described in the first aspect.

[0014] An overcurrent protection method according to an embodiment of this application acquires the current signal of an inductor at the current sampling moment and processes it to generate a corresponding rate of change parameter, thereby achieving real-time sensing of the current change trend. Based on this, a current limiting threshold is dynamically determined according to a preset desired protection current peak value, the rate of change parameter, and a delay compensation coefficient. This ensures that protection is triggered when the instantaneous value of the current signal exceeds the current limiting threshold, guaranteeing that the peak current actually turned off after the inherent delay time can stably converge to near the desired protection current peak value. This solves the problem of severe overshoot of peak current as the slope increases under traditional fixed threshold schemes, thus achieving reliable protection for power devices. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating an overcurrent protection method provided in an embodiment of this application; Figure 2 This is a flowchart illustrating the process of determining the current limiting threshold corresponding to the current sampling time in an overcurrent protection method provided in this application embodiment; Figure 3 This is a schematic diagram of a conventional overcurrent protection scheme provided in the embodiments of this application; Figure 4 This is a schematic diagram of an overcurrent protection method provided in an embodiment of this application; Figure 5 This is a characteristic curve between the current limiting threshold and the rate of change parameter in an overcurrent protection method provided in this application embodiment; Figure 6 This is a schematic diagram of the process for generating the rate of change parameter in an overcurrent protection method provided in an embodiment of this application; Figure 7 This is a schematic diagram of the process for generating the rate of change parameter in another overcurrent protection method provided in this application embodiment; Figure 8 This is a schematic diagram of an overcurrent protection method provided in an embodiment of this application; Figure 9 This is a schematic diagram of the structure of an overcurrent protection device provided in an embodiment of this application; Figure 10 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0017] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0018] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0019] It should be noted that the acquisition, storage, use, and processing of data in this application embodiment all comply with the relevant provisions of national laws and regulations.

[0020] It should be noted that in the embodiments of this application, certain software, components, models and other existing solutions in the industry may be mentioned. These should be regarded as exemplary and are only intended to illustrate the feasibility of implementing the technical solution of this application. However, it does not mean that the applicant has used or necessarily used the solution.

[0021] In the field of overcurrent protection for power electronic converters, real-time monitoring and rapid protection of inductor current are crucial for ensuring the safe operation of switching transistors and power devices. Precise overcurrent protection can effectively prevent current overshoot from causing overheating, breakdown, or burnout of power devices, thus ensuring the operational reliability and safety of power electronic converters.

[0022] However, there is currently a lack of overcurrent protection methods with good performance that can simultaneously handle different current rise rates under normal load conditions and sudden short-circuit conditions. Traditional technologies mostly employ fixed-threshold overcurrent protection schemes, which sample real-time current using a current sensor, compare it with a fixed preset reference value via a comparator, and then execute current-limiting measures by a microcontroller after determining an overcurrent. These methods assume that the signal processing link has no delay or that the delay is fixed and negligible, heavily relying on idealized assumptions. They cannot detect the continued current rise caused by the inherent system delay, resulting in delayed protection response and large overshoot.

[0023] Although there are some overcurrent protection methods based on software prediction, the existing methods only make judgments based on the current current amplitude and do not incorporate the current change rate parameter into the control loop, thus lacking the ability to predict and compensate for future current trends.

[0024] In view of the above, in order to solve the aforementioned technical problems, the embodiments of this application provide the following... Figure 1 This paper illustrates an overcurrent protection method. It should be noted that the application scenarios described in the above embodiments are for the purpose of more clearly illustrating the technical solutions of this application and do not constitute a limitation on the technical solutions provided in this application. Those skilled in the art will understand that with the emergence of new application scenarios, the technical solutions provided in this application are also applicable to similar technical problems. The overcurrent protection method provided in this application can be applied to various power electronic conversion device scenarios requiring dynamic current limiting protection of inductor current, such as photovoltaic inverters, energy storage converters, electric vehicle charging piles, and uninterruptible power supplies.

[0025] The following is combined with Figure 1 This application provides a detailed description of an overcurrent protection method based on an embodiment.

[0026] Figure 1 A flowchart illustrating an embodiment of the overcurrent protection method provided in this application is shown. Figure 1 As shown, the overcurrent protection method includes the following steps: S110: Obtain the current signal of the inductor at the current sampling time, process the current signal, and generate the rate of change parameter of the inductor at the current sampling time. The current signal is used to characterize the operating state of the inductor. S120, based on the preset expected protection current peak value, rate of change parameter and preset delay compensation coefficient, determines the current limiting threshold corresponding to the current sampling time; S130: If the instantaneous value of the current signal at the current sampling time exceeds the current limiting threshold, a protection trigger signal is generated, and the switching transistor in the circuit where the inductor is located is turned off based on the protection trigger signal.

[0027] As described above, an overcurrent protection method according to an embodiment of this application acquires the current signal of an inductor and generates a rate of change parameter to achieve real-time sensing of the current change trend. Based on this, a current limiting threshold is determined according to the desired protection current peak value, the rate of change parameter, and a delay compensation coefficient. Utilizing the physical law that the inductor current will continue to rise within its inherent delay time, the rate of change parameter quantitatively estimates the current increment during the delay period, thereby dynamically adjusting the current limiting threshold. This ensures that protection is triggered when the instantaneous value of the current signal exceeds the current limiting threshold, guaranteeing that the peak current actually turned off after the inherent delay time stably converges to near the desired protection current peak value. This improves upon the problem of severe overshoot of peak current as the slope increases under traditional fixed threshold schemes, thus achieving reliable protection for power devices.

[0028] The specific implementation methods of steps 110 to 130 above will be described in detail below.

[0029] In S110, the aforementioned inductor can be an inductor in a power electronic conversion device, such as an inverter output filter inductor, a bridge arm inductor in an energy storage converter, or a boost inductor, etc., which is not limited.

[0030] In a practical implementation, as an example, a current sensor collects the real-time current of the inductor at the current sampling moment, obtaining a current signal. After acquiring the current signal, a signal processing circuit processes it to generate a rate of change parameter corresponding to the inductor at the current sampling moment. In one example, the rate of change parameter can be calculated by differentiating the current signal using a differential operational amplifier to extract the instantaneous rate of change of the current, thereby generating the rate of change parameter. In another example, the current signal can also be sampled using an analog-to-digital converter to obtain the current value at the current sampling moment and the current value at the previous sampling moment, and the rate of change parameter can be obtained through differential calculation. It should be added that after generating the rate of change parameter, it can also be filtered to reduce noise interference and improve the accuracy of the rate of change parameter.

[0031] In S120, the aforementioned expected protection current peak value can be the maximum peak current allowed by the system design. The specific value can be determined comprehensively based on factors such as the current handling capability, heat dissipation conditions, and safety margins of the switching transistors and power devices in the power electronic converter. The aforementioned delay compensation coefficient can be a parameter used to compensate for the inherent delay time of the signal processing link. This inherent delay time can include, for example, the response delay of the current sensor, the propagation delay of the comparator, the interrupt response time of the microcontroller, and the turn-off time of the drive circuit. The aforementioned current limiting threshold is a dynamically adjusted current protection trigger point, used to compare with the real-time current to determine whether overcurrent protection is triggered.

[0032] In S130, the aforementioned protection trigger signal can be a level signal or a pulse signal used to indicate an overcurrent state. The aforementioned switching transistor can be a power switching device in a power electronic conversion device, such as a metal-oxide-semiconductor field-effect transistor, an insulated-gate bipolar transistor, or a silicon carbide device, etc., without limitation.

[0033] In practice, the instantaneous value of the current signal at the current sampling moment can be compared with the current limiting threshold determined in step 120. If the instantaneous value of the current signal at the current sampling moment exceeds the current limiting threshold, it indicates that the current in the inductor has reached the dynamic protection trigger point, and a protection trigger signal is generated. Subsequently, based on this protection trigger signal, the switching transistor corresponding to the inductor is turned off, that is, the switching transistor is controlled to turn off by the drive circuit, cutting off the current path and preventing the current from continuing to rise and causing overcurrent damage to the power device. It should be added that after generating the protection trigger signal, the signal can also be transmitted to the microcontroller, which will execute corresponding current limiting measures according to the preset protection strategy, such as turning off the switching transistor, reducing the output power, or switching to a safe operating mode.

[0034] Optionally, according to embodiments of this application, in conjunction with Figure 2 As shown, the above-mentioned S120, which determines the current limiting threshold corresponding to the current sampling moment based on the preset expected protection current peak value, rate of change parameter, and preset delay compensation coefficient, may include: S121, Based on the rate of change parameter and delay compensation coefficient corresponding to the current sampling time, determine the predicted current increment. The predicted current increment is used to characterize the expected rise of the current within the inherent delay time. S122 calculates the difference between the predicted current increment and the expected protection current peak value to generate the current limiting threshold corresponding to the current sampling time.

[0035] To facilitate understanding of the technical issues to be addressed in determining the aforementioned current limiting threshold, we will first combine... Figure 3 The relevant technical background is explained.

[0036] in, Figure 3 A schematic diagram of the current in a traditional overcurrent protection scheme is shown, such as... Figure 3 The I shown L1 As shown in the curve, when the inductor current rises at a small slope, the current rises from the set threshold I. limit After reaching and passing the inherent delay time Td, the actual turn-off peak I peak 1 is slightly higher than the set threshold I limit ;such as I L2 As shown in the curve, when the current rises at a large slope, such as Figure 3 As can be seen from the curve on the right, after the same inherent delay time Td, the actual turn-off peak value I... peak 2. The current rises even higher. This indicates that in the traditional fixed threshold scheme, after the inherent delay time Td, the actual protection point will rise with the increase of the current rise slope. Under sudden short circuit or heavy load change conditions, the actual protection point will rise even higher within the inherent delay time. In this case, if a fixed preset threshold is used for overcurrent protection, it is easy to cause the current limiting response to be untimely. To address this problem, the embodiments of this application achieve predictive compensation by first estimating the current increment during the delay period in S121 to S122, and then lowering the trigger threshold accordingly.

[0037] In S121, the aforementioned inherent delay time refers to the total time interval between the completion of current sampling and the actual execution of the turn-off operation by the switching transistor. This time interval may include, for example, the response delay of the current sensor, the transmission delay of the signal conditioning circuit, the decision delay of the comparator, the interrupt response delay of the microcontroller, and the turn-off delay of the drive circuit.

[0038] The aforementioned rate of change parameter is used to characterize the rate at which the inductor current changes with time. The aforementioned delay compensation coefficient is used to quantify the correspondence between the current rise amplitude and the rate of change parameter within the inherent delay time. Its typical value can be equal to the inherent delay time Td, or it can be adjusted within the range of Td to 1.2Td to provide additional protection margin.

[0039] The physical meaning of the predicted current increment is: if protection is triggered at the current sampling moment, the inductor current will continue to rise after the inherent delay time; essentially, it is an estimate of the current increment during the delay period. In practical implementation, for example, the predicted current increment can be obtained by multiplying the rate of change parameter by the delay compensation coefficient. For instance, when the detected inductor current rate of change parameter is 3A / µs and the delay compensation coefficient is 2µs, the predicted current increment is approximately 6A, meaning that the current will continue to rise by about 6A after protection is triggered before it is actually shut off.

[0040] In S122, the aforementioned expected protection current peak value refers to the maximum safe current value that the power devices in the power electronic conversion device are allowed to withstand. Its specific value can be determined comprehensively based on the current withstand rating of the switching transistor, heat dissipation conditions, and system safety margin. For example, for a MOSFET switching transistor with a rated current of 100A, the expected protection current peak value can be set to 120A.

[0041] In a specific implementation, for example, the current limiting threshold corresponding to the current sampling moment can be obtained by performing a difference calculation between the predicted current increment obtained in S121 and the preset expected protection current peak value. The physical logic is that the current limiting threshold is reduced by the magnitude of the predicted current increment in advance to compensate for the current rise during the inherent delay time, so that the peak current that is actually turned off after the inherent delay tends to be close to the peak value of the expected protection current.

[0042] To further explain the basis for determining S121 and S122, the derivation process of the current limiting threshold will be introduced below in conjunction with the physical laws of inductance.

[0043] According to the basic voltage-current relationship of an inductor, the voltage VL across the inductor and the rate of change of the inductor current dI(t) / dt at the current sampling time t satisfy the following equation (1): VL=L×(dI(t) / dt) (1) Where VL is the voltage across the inductor, L is the inductance value, and dI(t) / dt is the instantaneous rate of change of the inductor current.

[0044] In overcurrent protection scenarios, there is an inherent delay time Td from current sampling to the controller executing the protection action. During this inherent delay time Td, the inductor current will continue to rise, and its rise amplitude ΔI can be expressed as shown in the following equation (2): ΔI=(dI(t) / dt)×Td (2) As can be seen from equation (2), the rise amplitude ΔI is the physical expression of the predicted current increment in S121, that is, the predicted current increment can be determined by multiplying the rate of change parameter dI(t) / dt with the delay compensation coefficient.

[0045] Furthermore, when the system detects that the current has reached the current limiting threshold I... limit The peak current I at the actual turn-off time after the inherent delay time Td is triggered by the protection. peak As shown in equation (3): I peak =I limit +ΔI=I limit +(dI(t) / dt)×Td(3) To make the actual turn-off peak current I peak The desired peak protection current I tends to be reached under different rates of change. refIt can make I peak =I ref By combining equations (2) and (3) and working backwards, we can obtain the formula for calculating the current limiting threshold. This current limiting threshold can be determined based on the first formula, which is shown in equation (4) below: (4) Wherein, k is the delay compensation coefficient, and its typical value can be equal to the inherent delay time Td, or it can be adjusted within the range of Td to 1.2Td according to the system calibration results to provide additional safety margin. k×(dI(t) / dt) in equation (4) is the predicted current increment determined in S121, and the operation relationship of the expected protection current peak value minus the predicted current increment expressed by equation (4) is the difference operation in S122. That is to say, equation (4) is a numerical integration expression of the two sub-steps S121 and S122. The physical meaning of equation (4) shows that the current limiting threshold automatically decreases as the rate of change parameter increases. When the current rises rapidly, the current limiting threshold automatically decreases to trigger protection in advance, compensate for the current increment in the inherent delay time, and thus ensure that the final peak current tends to be near the peak value of the expected protection current. When the current rises slowly, the rate of change parameter tends to zero, and the current limiting threshold tends to the peak value of the expected protection current. At this time, the dynamic current limiting degenerates into the traditional fixed threshold current limiting method, which ensures the compatibility of the system under normal operating conditions.

[0046] For ease of understanding, the following is combined with Figures 4 to 6 The technical effects that can be achieved by S121 to S122 are explained.

[0047] like Figure 4 The I on the left L1 As shown in the curve, when the inductor current rises at a relatively small slope, the corresponding current limiting threshold is set at I. limit 1. Due to the inherent delay time Td in the signal link, the current will continue to rise to the final peak I. peak The shutdown was implemented only afterward. And if... Figure 4 Right curve I L2 As shown, when the current rise rate increases sharply, the current limiting threshold is automatically reduced to I based on the rate of change parameter. limit 2 (and I limit 2 limit 1). Precisely because a lower trigger threshold is used, even after experiencing the same inherent delay time Td, the current eventually climbs to a peak value I. peak It also maintains consistency with low-slope operating conditions. This mechanism, through dynamic adjustment of the current-limiting threshold, successfully compensates for the inherent delay time of the system, ensuring that the actual protection peak point remains uniform and stable at I when facing fault currents with different rise slopes. peak nearby.

[0048] ​As an example, such as Figure 5 As shown, Figure 5 The characteristic curves showing the relationship between the current limiting threshold and the rate of change parameter are presented, intuitively reflecting the correspondence between the two. Figure 5 The horizontal axis of the characteristic curve represents the rate of change of the inductor current. The vertical axis represents the current limiting threshold. The curve reflects the linear relationship that the current limiting threshold decreases as the rate of change of current increases.

[0049] Specifically, when the current change rate parameter When the value is 0, that is, when the inductor current is in a steady state or a slowly changing condition, the current limiting threshold is [value missing]. Reaching the maximum value ,at this time Equal to the preset expected peak protection current The dynamic current limiting mechanism degenerates into a traditional fixed threshold protection method to ensure system compatibility under normal operating conditions. This is due to the change rate parameter... The increase in the current limiting threshold It decreases linearly along a straight line, and its decreasing slope is determined by the delay compensation coefficient. The decision is as shown in equation (4) above. When the current change rate parameter increases to a certain value, the current limiting threshold drops to its minimum value. This minimum value is set based on the safe operating area of ​​the power device and the minimum conduction requirements of the system to prevent false triggering caused by an excessively low current limiting threshold.

[0050] As a specific example, in the application scenario of electric vehicle charging stations, if the peak protection current is expected to be... Set to 50A, delay compensation coefficient With a calibration of 2µs, the current limiting threshold is 50A when the inductor current change rate is 0A / µs; it linearly decreases to 48A when the change rate is 1A / µs; and it drops to 42A under short-circuit conditions with a change rate of 4A / µs. This characteristic curve visually demonstrates the adaptive mechanism of this application, which dynamically adjusts the current limiting threshold using the change rate parameter, mathematically guaranteeing that the inherent delay time will be sufficient to cover the current. The actual peak turn-off current It always converges to the desired protection current peak. nearby.

[0051] Therefore, this embodiment obtains the predicted current increment by multiplying the rate of change parameter by the delay compensation coefficient, and then uses the difference between the expected protection current peak and the predicted current increment to generate a current limiting threshold. This allows the trigger threshold to be lowered before the current reaches the expected peak value, compensating for the current rise during the inherent delay period. For example, under short-circuit conditions of L=100µH, Vbus=400V, and Td=2µs, the peak overshoot of the traditional fixed threshold scheme can reach approximately 8A; while in this embodiment, the current limiting threshold automatically decreases as the slope increases, making the actual turn-off peak value approach the expected protection current peak value, significantly reducing the overshoot amplitude, and achieving adaptive protection for different current rise slope conditions.

[0052] Optionally, according to some embodiments of this application, in conjunction with Figure 6 As shown, S110 involves acquiring the current signal of the inductor at the current sampling moment, processing the current signal to generate the rate of change parameter of the inductor at the current sampling moment, which may include: S111, Based on the current signal corresponding to the current sampling time and the current signal corresponding to the previous sampling time, determine the deviation component corresponding to the current sampling time; S112, based on the deviation component and the sampling time interval, generates the rate of change parameter, where the sampling time interval is the time difference between the current sampling time and the previous sampling time.

[0053] The following is a detailed explanation of steps 111 to 112 above.

[0054] In S111, the current signal corresponding to the previous sampling time refers to the current signal acquired at the previous sampling time adjacent to the current sampling time. The aforementioned deviation component refers to the difference between the current sample value at the current sampling time and the current sample value at the previous sampling time, and its physical meaning is the change in inductor current within a sampling time interval.

[0055] In practical implementation, as an example, the current signal of the inductor can be sampled using an analog-to-digital converter to obtain the current value at the current sampling moment. Then, the stored current value from the previous sampling moment is retrieved, and the two are subtracted to obtain the deviation component. For example, if the current sample value at the previous sampling moment was 10A and the current sample value at the current sampling moment is 13A, the deviation component is 3A, indicating that the current increased by 3A during the sampling interval. It should be noted that the determination of the deviation component is not limited to directly subtracting two adjacent sample values; it can also combine multiple historical sample values ​​for differential calculation to better reflect the current change trend.

[0056] In S112, the aforementioned sampling time interval is the time difference between the current sampling moment and the previous sampling moment, and its magnitude is related to the sampling frequency. For example, if the sampling frequency is 1MHz, then the sampling time interval is 1µs. The aforementioned rate of change parameter refers to the ratio of the deviation component to the sampling time interval, and its physical meaning is the average rate of change of the inductor current per unit time, which can be regarded as a discretized approximation of the rate of change of the continuous current signal.

[0057] In a specific implementation, for example, the rate of change parameter can be obtained by dividing the deviation component obtained in S111 by the sampling time interval. For example, if the deviation component is 3A and the sampling time interval is 1µs, then the rate of change parameter is 3A / µs.

[0058] Under discrete sampling conditions, the sampling time interval Δt is a finite value. In this case, the difference quotient can be used to approximate the derivative, resulting in the following expression for the calculation of the rate of change parameter as shown in equation (5): dI(t) / dt≈ΔI / Δt=(I2-I1) / (t2-t1) (5) Where I2 is the current value at the current sampling time, I1 is the current value at the previous sampling time, t2 is the current sampling time, t1 is the previous sampling time, Δt=t2-t1 is the sampling time interval, and ΔI=I2-I1 is the deviation component. As can be seen from equation (5), the rate of change parameter is the ratio of the deviation component to the sampling time interval, and the smaller the sampling time interval, the closer the difference approximation result is to the true instantaneous rate of change.

[0059] It should be added that after obtaining the rate of change parameter in S112 above, in order to reduce the impact of sampling noise, quantization error and instantaneous disturbance on the calculation result of the rate of change, the rate of change parameter can also be filtered.

[0060] In practical implementation, due to factors such as electromagnetic interference, switching noise, and ADC quantization errors that may exist during current sampling, the directly calculated rate of change parameter may exhibit instantaneous jumps. Without processing, this could lead to undesirable fluctuations in the subsequent current limiting threshold. Therefore, this embodiment of the application can filter the rate of change parameter to obtain a stable one. Filtering can be implemented in various ways. Thus, through filtering, high-frequency noise can be suppressed while preserving the true trend of current change, improving the accuracy and stability of the rate of change parameter.

[0061] As examples, filtering the rate of change parameter can be achieved using a first-order low-pass filter. The first-order low-pass filter suppresses high-frequency noise by weighting the current sampled value with the filtering result from the previous time step according to a certain ratio. Furthermore, to also suppress occasional pulse interference, a moving average filter can be performed before the first-order low-pass filter; that is, the arithmetic mean of N consecutive sampled values ​​is calculated before applying the first-order low-pass filter. As an example, N can be 8, meaning the average of the current sampled value and the previous 7 consecutive sampled values ​​is used as the input to the first-order low-pass filter. Therefore, by filtering the rate of change parameter, this embodiment of the application can reduce the erroneous fluctuations in the current limiting threshold caused by sampling noise, quantization errors, and instantaneous disturbances, thereby improving the accuracy and stability of the rate of change parameter.

[0062] Therefore, this embodiment of the application determines the deviation component by the difference between the current signals at adjacent sampling times, and then obtains the rate of change parameter by dividing the deviation component by the sampling time interval, thereby realizing real-time extraction of the current change trend during the sampling process. Furthermore, since a combination of differential and filtering methods can be used, sampling noise and instantaneous disturbances can be suppressed while preserving the true current change trend, reducing the erroneous fluctuation of the current limiting threshold caused by noise.

[0063] Optionally, according to some embodiments of this application, in conjunction with Figure 7 As shown, the rate of change parameter of the inductor element at the current sampling time may also include: S113 performs differentiation on the current signal to generate an analog electrical signal; S114 performs analog-to-digital conversion on the analog electrical signal to obtain the rate of change parameter.

[0064] In S113, the aforementioned differential operation refers to calculating the rate of change of the current signal over time, which can be implemented at the circuit level using a differential operational amplifier. The aforementioned analog electrical signal refers to the continuous voltage signal obtained after the differential operation, whose amplitude is proportional to the rate of change of the current.

[0065] As an example, the analog electrical signal output from the current sensor is fed into a differentiating operational amplifier. The amplifier performs a differentiating operation on the input signal, outputting an analog electrical signal proportional to the rate of change of the input signal. For instance, when the inductor current rises at a rate of 3 A / µs, the amplitude of the analog electrical signal output by the differentiating operational amplifier is proportional to this rate of change; that is, the greater the rate of change of the current, the greater the amplitude of the output analog electrical signal. It should be noted that the differentiating operation is not limited to an ideal differentiating circuit; practical differentiating circuits with input current-limiting resistors or active differentiators can also be used to reduce the influence of high-frequency noise. This application does not limit the implementation in this regard.

[0066] In S114, the aforementioned analog-to-digital conversion refers to the process of converting a continuous analog electrical signal into a discrete digital signal, which can be accomplished by an analog-to-digital converter. The aforementioned rate of change parameter refers to the digital quantity of the current change rate obtained after analog-to-digital conversion and used in subsequent stages.

[0067] In a specific implementation, for example, the analog electrical signal obtained in S113 can be sent to an analog-to-digital converter (ADC). The ADC samples and quantizes the analog electrical signal, and outputs a digital quantity corresponding to the amplitude of the analog electrical signal. This digital quantity is the rate of change parameter. For example, if the amplitude of the analog electrical signal is 3V, and the quantization reference of the ADC is set to 1A / µs for 1V, then the converted rate of change parameter is approximately 3A / µs.

[0068] In specific implementation, such as Figure 8 As shown, Figure 8 This diagram illustrates the principle block diagram of how the rate of change parameter is extracted and overcurrent protection is performed using steps 113 to 114 as described above in the embodiments of this application. Specifically, in the case of… Figure 8 During the overcurrent protection process shown, the current sensor 801 samples the current of the inductor in real time. This current signal is divided into two paths: one path is sent to the differential operational amplifier 802 for differentiation to obtain the rate of change parameter; the other path is sent to the comparator 804 as the instantaneous current value. Simultaneously, the rate of change parameter output by the differential operational amplifier 802 is multiplied by the delay compensation coefficient k, and then subtracted from the desired protection current peak value I in the subtractor 803. ref Perform the difference operation to obtain the dynamically adjusted current limiting threshold I. limit The comparator 804 compares the real-time instantaneous current value with the current limiting threshold I. limit If the instantaneous value of the real-time current exceeds the current limiting threshold I, then... limit If the comparator 804 outputs a high-level protection trigger signal to the microcontroller 805, the microcontroller 805 will respond to the protection trigger signal and immediately control the switch 806 to turn off through the drive circuit. This process fully utilizes the fast response capability of the differential operational amplifier 802 to the rate of change of current, so that the current limiting threshold can be adjusted in real time according to the current rise slope, thereby compensating for the continued rise of current during the inherent delay time between current sampling and actual turn-off of the switch 806, and realizing that the actual turn-off peak current stably converges to near the desired protection current peak.

[0069] Therefore, the embodiments of this application are implemented through Figure 8 The circuit architecture shown uses a hybrid signal processing approach that combines analog domain differential operations with digital domain threshold adjustment to achieve real-time extraction of the inductor current change rate and dynamic adjustment of the current limiting threshold. This enables the protection action to be triggered in advance under conditions of sudden short circuits or heavy load changes with large current rise slopes, effectively suppressing peak current overshoot and achieving reliable protection for power devices.

[0070] It should be noted that, Figure 8 The specific circuit structure shown is only an exemplary embodiment of this application. Those skilled in the art can replace or adjust some of the functional modules according to actual needs. For example, the differential operational amplifier 802 can also be replaced with a digital domain differential calculation module, and the comparator 804 can also be integrated into the analog comparator unit inside the microcontroller 805. These variations do not depart from the protection scope of this application.

[0071] This application embodiment performs differentiation on the current signal in the analog domain to obtain an analog electrical signal proportional to the rate of change of current. This signal is then converted from analog to digital to generate a rate of change parameter, thereby enabling real-time extraction of the current change trend during the sampling stage. Since the differentiation operation is performed continuously in the analog domain, it can promptly capture instantaneous changes in current, shortening the acquisition time of the rate of change. For example, when the current rises rapidly under short-circuit conditions, the differential operational amplifier can quickly output an analog electrical signal reflecting the rate of change. After analog-to-digital conversion, the rate of change parameter is obtained, providing timely input for subsequent dynamic current limiting and improving the response speed of overcurrent protection and its adaptability to different current rise slopes.

[0072] Optionally, according to some embodiments of this application, after generating the current limiting threshold corresponding to the current sampling time, the method further includes: If the rate of change parameter is less than the first rate of change threshold, the current limiting threshold is determined to be the expected protection current peak value; If the rate of change parameter is greater than or equal to the second rate of change threshold, the current limiting threshold is determined to be the preset minimum allowable current limiting value, wherein the first rate of change threshold is less than the second rate of change threshold.

[0073] To facilitate understanding of the technical background of the above-mentioned limiting processing, let's first combine... Figure 4 Please provide an explanation, such as Figure 4 As shown, when the inductor current rises at a relatively small slope, the corresponding current limiting threshold is set to I. limit 1; When the current rise rate increases sharply, the current limiting threshold decreases to I. limit 2. However, when the rate of change parameter further approaches zero or increases to an extreme value, if the current limiting threshold is still determined according to the above decreasing relationship, the current limiting threshold may exceed the expected protection current peak value, or drop too low or even close to zero, resulting in an unreasonable protection threshold. Therefore, the embodiments of this application constrain the current limiting threshold through segmented limiting processing.

[0074] In the first scenario, where the rate of change parameter is less than the first rate of change threshold, the aforementioned first rate of change threshold refers to the rate of change threshold used to define the range of slow current changes. When the rate of change parameter is below this value, it indicates that the inductor current rises slowly or is essentially in a steady state. The aforementioned expected protection current peak value refers to the maximum safe current value that the power devices in the power electronic converter are allowed to withstand. Its specific value can be determined comprehensively based on the current withstand rating of the switching transistor, heat dissipation conditions, and system safety margin.

[0075] In practical implementation, as an example, when the rate of change parameter is less than the first rate of change threshold, for example, when the rate of change parameter is 0.1A / µs and the first rate of change threshold is 0.2A / µs, the inductor current rises extremely slowly. In this case, the current limiting threshold is directly set to the desired peak protection current, causing dynamic current limiting to degenerate into a traditional fixed threshold current limiting method. The advantages of this approach are twofold: firstly, under steady-state conditions with slowly changing current, the impact of the current change rate on peak overshoot is relatively small, and the protection requirements can be met without lowering the current limiting threshold; secondly, it avoids the current limiting threshold being incorrectly raised above the desired peak protection current due to noise in the rate of change parameter measurement, thus ensuring that the protection threshold does not exceed the design-allowed peak value.

[0076] In the second scenario, where the rate of change parameter is greater than or equal to the second rate of change threshold, the aforementioned second rate of change threshold refers to the rate of change threshold used to define the range of rapid current changes. When the rate of change parameter reaches or exceeds this value, it indicates that the inductor current is in a rapidly rising operating condition. The aforementioned minimum allowable current limit value refers to the lowest value that the current limit threshold is allowed to reach, used to prevent false triggering caused by an excessively low current limit threshold.

[0077] In practical implementation, as an example, when the rate of change parameter is greater than or equal to the second rate of change threshold, for instance, when the rate of change parameter is 5A / µs and the second rate of change threshold is 4A / µs, the inductor current rises extremely rapidly. If the current limiting threshold continues to decrease in a decreasing manner, the current limiting threshold may drop too low, even below the normal operating current level, thus causing false triggering during normal load fluctuations. Therefore, the current limiting threshold is clamped to a preset minimum allowable current limit value to prevent the current limiting threshold from being reduced indefinitely.

[0078] It should be noted that the first rate of change threshold is less than the second rate of change threshold. That is, between the first rate of change threshold and the second rate of change threshold, the current limiting threshold is determined according to the existing relationship between it and the rate of change parameter, while clamping is performed in the two ends of the interval.

[0079] For ease of understanding, the above segmented amplitude limiting process can be expressed by the segmented expressions of equations (6) and (7) as follows: When dI(t) / dt<dI / dt_min: I limit =I ref (6) When dI(t) / dt≥dI / dt_max: I limit =I limit_min (7) Wherein, dI(t) / dt is the change rate parameter, dI / dt_min is the first change rate threshold, dI / dt_max is the second change rate threshold, I ref is the desired protection current peak value, I limit_min is the minimum allowable current limiting value, and dI / dt_min<dI / dt_max is satisfied.

[0080] Regarding the determination of the second change rate threshold, it can be derived according to the following physical relationship: the current limiting threshold decreases as the change rate parameter increases, and its decreasing rate is related to the delay compensation coefficient. When the change rate parameter is 0, the current limiting threshold is equal to the desired protection current peak value I ref ; when the change rate parameter increases to the second change rate threshold dI / dt_max, the current limiting threshold just drops to the minimum allowable current limiting value I limit_min , that is, the current limiting threshold is reduced by (I ref -I limit_min ), and the corresponding increment of the change rate parameter is dI / dt_max. Accordingly, the calculation expression of the second change rate threshold shown in the following formula (8) can be obtained: dI / dt_max=(I ref -I limit_min ) / k (8) Wherein, k is the delay compensation coefficient. It can be seen from formula (8) that the second change rate threshold is proportional to the difference between the desired protection current peak value and the minimum allowable current limiting value, and inversely proportional to the delay compensation coefficient, that is, the larger the allowable adjustment interval of the current limiting threshold and the smaller the delay compensation coefficient, the larger the second change rate threshold.

[0081] Regarding the determination of the first change rate threshold, it can be set to the change rate value corresponding to when the current limiting threshold reaches the desired protection current peak value, which approaches zero under ideal conditions. In practical applications, considering the measurement noise of the change rate parameter, the first change rate threshold can be set to a positive number slightly greater than zero to cover the tiny change rate fluctuation caused by the noise. For example, the first change rate threshold can be set to 0.2A / µs.

[0082] The specific value for determining the minimum permissible current limit can be set according to the safe operating area of ​​the power device and the minimum conduction requirements of the system. For example, it can be set to a value higher than the normal operating current but lower than the expected peak protection current. For instance, if the expected peak protection current is 50A and the normal operating current is 40A, then the minimum permissible current limit can be set to 42A.

[0083] Combination Figure 5 The characteristic curve shown above, relating the current limiting threshold to the rate of change parameter, provides a visual illustration of this segmented amplitude limiting process. Figure 5 The horizontal axis represents the rate of change parameter, and the vertical axis represents the current limiting threshold. Within the range where the rate of change parameter is less than the first rate of change threshold, the current limiting threshold remains at the desired peak protection current, and the characteristic curve exhibits a horizontal segment. Within the range where the rate of change parameter is greater than or equal to the second rate of change threshold, the current limiting threshold remains at the minimum allowable current limiting value, and the characteristic curve exhibits another horizontal segment. Between the two thresholds, the current limiting threshold decreases as the rate of change parameter increases, and the characteristic curve exhibits a descending segment. Therefore, Figure 5 The characteristic curves visually demonstrate the effect of the embodiments of this application on the upper and lower limits of the current limiting threshold.

[0084] This application imposes upper and lower limits on the current limiting threshold by clamping it to the desired peak protection current when the rate of change parameter is too small, and clamping it to the minimum permissible current limit when the rate of change parameter is too large. The lower limit constraint helps reduce the possibility of the current limiting threshold being raised due to measurement noise and weakening protection capability under steady-state or slowly changing operating conditions. The upper limit constraint helps reduce the possibility of the current limiting threshold dropping too low under rapidly rising operating conditions such as short circuits, leading to false triggering during normal fluctuations. For example, in a scenario where the desired peak protection current is 50A and the minimum permissible current limit is 42A, the current limiting threshold is constrained within the range of 42A to 50A, thus balancing protection reliability and resistance to false triggering, and improving the adaptability of overcurrent protection to different operating conditions.

[0085] Optionally, according to some embodiments of this application, after the switch in the circuit containing the inductor is turned off based on a protection trigger signal, the overcurrent protection method may further include the following steps: If the instantaneous current value at each sampling time within a preset time period after the inductor is turned off is less than the preset recovery threshold, the overcurrent fault status flag corresponding to the inductor is reset. Based on the overcurrent fault status flag after reset, the enable signal of the corresponding switch of the inductor is output to enable the inductor to resume current transmission.

[0086] As described above, an overcurrent protection method according to an embodiment of this application determines whether an overcurrent fault has been resolved by monitoring whether the instantaneous current value at each sampling moment within a preset time period has decayed to below a preset recovery threshold after the switch is turned off. Based on this, the overcurrent fault status flag is reset when the inductor current stably falls back to the safe range, and an enable signal for the switch is output based on the reset flag. Thus, when the overcurrent fault is not truly resolved, the switch can remain in the off state to reduce false turn-on and consequently reduce secondary overcurrent impacts. After the inductor current recovers to the safe range, the switch can promptly resume current transmission, reducing prolonged downtime, thereby achieving automatic recovery of current transmission in the inductor element after the overcurrent fault is resolved.

[0087] The specific implementation methods of the above steps will be described in detail below.

[0088] The aforementioned preset time period refers to a time window used to observe current decay after the inductor is turned off. Its duration can be related to factors such as the inductance value of the circuit containing the inductor, the freewheeling voltage, and the desired current decay magnitude. The aforementioned sampling times refer to the points within this preset time period where current is collected sequentially according to the sampling frequency. The aforementioned preset recovery threshold is a current reference value used to determine whether the overcurrent fault has been resolved. When the inductor current decays below this value, it can be considered that the inductor current has returned to a safe range. The aforementioned overcurrent fault status indicator is a flag used to record whether the inductor is in an overcurrent fault state. It can be a variable in a software program or a bit in a hardware register; there are no limitations on this.

[0089] In a specific implementation, for example, when the switching transistor is turned off due to overcurrent protection, the current in the inductor continues to flow through the freewheeling circuit and gradually decays. Simultaneously, the current sampling circuit continuously samples the current of the inductor at a sampling frequency within the preset time period, obtaining the instantaneous current value corresponding to each sampling moment. Then, the instantaneous current value corresponding to each sampling moment is compared with a preset recovery threshold. If the instantaneous current value corresponding to each sampling moment within the preset time period is less than the preset recovery threshold, it indicates that the inductor current has stabilized and fallen back to a safe range. At this time, the overcurrent fault status flag corresponding to the inductor is reset, that is, its value is restored from representing a fault state to representing a normal state. For example, when overcurrent protection is triggered, the overcurrent fault status flag can be set to logic 1 to indicate a fault state; when the inductor current stabilizes and decays below the preset recovery threshold, the flag is reset to logic 0 to indicate a normal state.

[0090] As an example, if the preset time period is 5µs and the sampling frequency is 1MHz, then the preset time period contains 5 sampling moments. The overcurrent fault status flag will only be reset if the instantaneous current value corresponding to these 5 sampling moments is less than the preset recovery threshold.

[0091] It should be added that the aforementioned preset recovery threshold can be set to a value lower than the current limiting threshold but higher than the normal load current to create a hysteresis characteristic, thereby reducing the frequent switching of the overcurrent fault status indicator caused by the inductor current repeatedly crossing near the recovery threshold. As an example, if the normal load current is approximately 35A and the current limiting threshold is approximately 48A, then the preset recovery threshold can be set to 40A.

[0092] The aforementioned overcurrent fault status indicator after reset refers to an indicator used to indicate that the inductor has recovered from the overcurrent fault state after a reset operation. The aforementioned enable signal refers to a signal used to control whether the switching transistor drive circuit allows the switching transistor to be turned on; for example, it can be a level signal. The aforementioned switching transistor can be a power switching device in a power electronic conversion device, such as a metal-oxide-semiconductor field-effect transistor, an insulated-gate bipolar transistor, or a silicon carbide device, etc., and is not limited thereto.

[0093] In a specific implementation, for example, after the overcurrent fault status flag is reset to a value indicating a normal state, an enable signal is output to the drive circuit of the switching transistor based on the reset overcurrent fault status flag. This releases the restriction on turning on the switching transistor, allowing it to be turned on again according to normal control logic, thereby restoring current transmission in the inductor. Combined with... Figure 8 As shown, in Figure 8 During the overcurrent protection process shown, the reset of the overcurrent fault status indicator and the output of the enable signal can be executed by the microcontroller 805. That is, after confirming that the overcurrent fault status indicator has been reset, the microcontroller 805 outputs an enable signal to the switch 806 through the drive circuit, so that the switch 806 is restored to controlled turn-on.

[0094] It should be added that if the overcurrent fault status indicator is not reset, the enable signal can be kept in an invalid state, keeping the switch continuously off, thereby reducing the likelihood of the switch being turned on again before the overcurrent fault is resolved. For example, if the inductor current has not yet decayed below the preset recovery threshold, the overcurrent fault status indicator remains at logic 1, the enable signal remains at a low level, and the switch remains off.

[0095] Therefore, this embodiment monitors the instantaneous current values ​​at each sampling time within a preset time period after the switch is turned off, and resets the overcurrent fault status flag when all values ​​decay to below a preset recovery threshold. Then, based on the reset flag, an enable signal is output to restore the switch's on-time, achieving automatic recovery of inductor current transmission after the overcurrent fault is resolved. Since the reset judgment is based on the inductor current steadily decaying to a safe range, it helps reduce secondary overcurrent surges caused by accidental switching on of the switch before the fault is resolved. It also helps reduce losses caused by prolonged downtime after the current returns to normal, thus improving the timeliness and reliability of system recovery while ensuring device safety.

[0096] Based on the same inventive concept and the overcurrent protection method provided in the above embodiments, this application also provides an overcurrent protection device corresponding to the above overcurrent protection method. The following describes... Figure 9 This overcurrent protection device is described in detail.

[0097] like Figure 9 As shown, the overcurrent protection device 900 includes: The sampling module 910 is used to acquire the current signal corresponding to the inductor element in the power electronic converter at the current sampling time. The signal processing module 920 is used to process the current signal, generate the rate of change parameter of the inductor at the current sampling time, and determine the current limiting threshold at the current sampling time based on the preset expected protection current peak value, the rate of change parameter and the preset delay compensation coefficient. The current signal is used to characterize the operating state of the inductor. The execution module 930 is used to generate a protection trigger signal when the instantaneous value of the current signal corresponding to the current sampling time exceeds the current limiting threshold, and to perform the turn-off operation of the switching transistor in the circuit where the inductor is located based on the protection trigger signal.

[0098] Figure 10 A schematic diagram of the hardware structure of the control device for the overcurrent protection method described in the embodiments of this application is shown.

[0099] The control device may include a processor 1101 and a memory 1102 storing computer program instructions.

[0100] Specifically, the processor 1101 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0101] Memory 1102 may include mass storage for data or instructions. For example, and not limitingly, memory 1102 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 1102 may include removable or non-removable (or fixed) media. Where appropriate, memory 1102 may be internal or external to a control device. In a particular embodiment, memory 1102 is a non-volatile solid-state memory.

[0102] Memory may include read-only memory (ROM), random access memory (RAM), disk storage media devices, optical storage media devices, flash memory devices, and electrical, optical, or other physical / tangible memory storage devices. Therefore, typically, memory includes one or more tangible (non-transitory) computer storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to one aspect of this disclosure.

[0103] The processor 1101 implements any of the overcurrent protection methods described in the above embodiments by reading and executing computer program instructions stored in the memory 1102.

[0104] In one example, the control device for the overcurrent protection method may further include a communication interface 1103 and a bus 1110. Wherein, as... Figure 10 As shown, the processor 1101, memory 1102, and communication interface 1103 are connected through bus 1110 and complete communication with each other.

[0105] The communication interface 1103 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0106] Bus 1110 includes hardware, software, or both, that couples components of a control device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 1110 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, this application contemplates any suitable bus or interconnect.

[0107] The control device of this overcurrent protection method can execute the overcurrent protection method in the embodiments of this application, thereby realizing the overcurrent protection method described in the above embodiments.

[0108] In addition, in conjunction with the overcurrent protection methods in the above embodiments, this application embodiment can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the overcurrent protection methods in the above embodiments.

[0109] This application also provides a computer program product, including a computer program that, when executed by a processor, implements any of the overcurrent protection methods described in the above embodiments.

[0110] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0111] The functional blocks shown in the above block diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0112] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0113] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by special-purpose hardware performing the specified functions or actions, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0114] The above are merely specific embodiments of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. An overcurrent protection method applied to a power electronic conversion device, wherein the power electronic conversion device includes at least an inductive element, characterized in that, include: The current signal of the inductor at the current sampling time is acquired, and the current signal is processed to generate the rate of change parameter of the inductor at the current sampling time. The current signal is used to characterize the operating state of the inductor. Based on the preset expected protection current peak value, the rate of change parameter, and the preset delay compensation coefficient, the current limiting threshold corresponding to the current sampling time is determined; If the instantaneous value of the current signal at the current sampling time exceeds the current limiting threshold, a protection trigger signal is generated, and the switching transistor in the circuit where the inductor is located is turned off based on the protection trigger signal. After generating the current limiting threshold corresponding to the current sampling time, the method further includes: If the rate of change parameter is less than the first rate of change threshold, the current limiting threshold is determined to be the expected protection current peak value; If the rate of change parameter is greater than or equal to the second rate of change threshold, the current limiting threshold is determined to be a preset minimum allowable current limiting value, wherein the first rate of change threshold is less than the second rate of change threshold. The second rate of change threshold is determined based on the difference between the expected protection current peak value and the minimum allowable current limit value and the delay compensation coefficient. The second rate of change threshold value is equal to the difference between the expected protection current peak value and the minimum allowable current limit value divided by the delay compensation coefficient. The minimum allowable current limit value is set according to the safe operating area of ​​the power device in the circuit where the inductor is located and the minimum conduction requirement of the system in the circuit where the inductor is located. The minimum allowable current limit value is higher than the normal operating current of the circuit where the inductor is located and lower than the expected protection current peak value.

2. The method according to claim 1, characterized in that, Determining the current limiting threshold corresponding to the current sampling time includes: Based on the rate of change parameter and the delay compensation coefficient corresponding to the current sampling time, the predicted current increment is determined, and the predicted current increment is used to characterize the expected rise of the current within the inherent delay time. The difference between the predicted current increment and the expected protection current peak value is calculated to generate the current limiting threshold corresponding to the current sampling time.

3. The method according to claim 1, characterized in that, The step of acquiring the current signal of the inductor at the current sampling time and processing the current signal to generate the rate of change parameter of the inductor at the current sampling time includes: Based on the current signal corresponding to the current sampling time and the current signal corresponding to the previous sampling time, determine the deviation component corresponding to the current sampling time; Based on the deviation component and the sampling time interval, the rate of change parameter is generated, wherein the sampling time interval is the time difference between the current sampling time and the previous sampling time.

4. The method according to claim 1, characterized in that, The generation of the rate of change parameter of the inductor element at the current sampling time includes: The current signal is differentiated to generate an analog electrical signal; The analog electrical signal is converted from analog to digital to obtain the rate of change parameter.

5. The method according to claim 1, characterized in that, After the method performs the turn-off operation of the switching transistor in the circuit where the inductor is located based on the protection trigger signal, the method further includes: If the instantaneous current value at each sampling time within a preset time period after the inductor is turned off is less than the preset recovery threshold, the overcurrent fault status flag corresponding to the inductor is reset. Based on the overcurrent fault status identifier after reset, the enable signal of the switch corresponding to the inductor element is output.

6. An overcurrent protection device, characterized in that, include: The sampling module is used to acquire the current signal corresponding to the inductive element in the power electronic conversion device at the current sampling time. The signal processing module is used to process the current signal, generate the rate of change parameter of the inductor element at the current sampling time, and determine the current limiting threshold at the current sampling time based on the preset expected protection current peak value, the rate of change parameter and the preset delay compensation coefficient. The current signal is used to characterize the operating state of the inductor element. The execution module is configured to generate a protection trigger signal when the instantaneous value of the current signal corresponding to the current sampling time exceeds the current limiting threshold, and to perform a turn-off operation of the switching transistor in the circuit where the inductor is located based on the protection trigger signal.

7. An electronic device, characterized in that, The device includes: a processor and a memory storing computer program instructions; the processor, when executing the computer program instructions, implements the overcurrent protection method as described in any one of claims 1-5.

8. A computer storage medium, characterized in that, The computer storage medium stores computer program instructions, which, when executed by a processor, implement the overcurrent protection method as described in any one of claims 1-5.

9. A computer program product, characterized in that, The computer program product includes computer program instructions that, when executed by a processor, implement the overcurrent protection method according to any one of claims 1-5.

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