Control method and control device for electronic fuse

Abstract

The invention discloses a control method and a control device for an electronic fuse. The control method comprises the following steps: detecting current passing through the electronic fuse at a time interval; storing a plurality of current values detected at a plurality of time points; and determining a plurality of stroke currents corresponding to a plurality of stroke times according to the plurality of current values, including determining the plurality of stroke currents by dividing the plurality of stroke currents into two parts, the first part being obtained by performing a plurality of arithmetic average operation programs on the stored current values, and the second part being obtained by performing a plurality of arithmetic average operation programs on the stored current values. The second part is obtained by carrying out a plurality of arithmetic average operation programs on the current stroke current and the previously calculated stroke current; and comparing the plurality of stroke currents with preset current values corresponding to the plurality of stroke times in a preset stroke current-stroke time curve to generate a plurality of comparison results so as to control the state of the electronic fuse.

Description

TECHNICAL FIELD

[0001] The present application relates to a control method and a control device for an electronic fuse, and in particular to a control method and a control device for an electronic fuse that can improve computational efficiency and reduce resource requirements. BACKGROUND

[0002] Electronic fuses (eFuse) play an important role in modern electronic systems, especially in the fields of automotive electronics, power management, and industrial control. Traditional thermal fuses permanently break when detecting overcurrent, while electronic fuses can achieve resettable overcurrent protection through control circuits.

[0003] The most basic control method for electronic fuses is to use a fixed threshold comparator. When the detected current exceeds the preset threshold, the control circuit will immediately cut off the current. This method is simple and direct, but it cannot handle short-term current pulses or long-term low-intensity overload. To solve this problem, existing technologies introduce a time delay mechanism, which uses a fixed time window to accumulate current values, and if the average current within the time window exceeds the threshold, the protection mechanism is triggered. This method improves the anti-interference ability of the system, but it is still difficult to adapt to different time scales of overcurrent situations.

[0004] More complex control methods use variable time windows or multiple protection thresholds, which attempt to simulate the current-time curve of traditional thermal fuses to provide more accurate protection at different time scales. However, this method usually requires a large amount of computational resources and complex hardware circuits, increasing the cost and power consumption of the system.

[0005] In addition, most existing electronic fuse control methods are based on fixed protection parameters. However, in actual applications, the working environment and load characteristics of electronic systems may change. For example, in automotive applications, different wiring harnesses may have different ignition characteristics, and these characteristics may change over time. Fixed parameter control methods are difficult to adapt to this dynamically changing environment.

[0006] Therefore, for the control of electronic fuses, how to provide accurate overcurrent protection at various time scales while having high computational efficiency, low resource requirements, strong flexibility, and being able to adapt to actual use conditions has become one of the goals of the industry. SUMMARY

[0007] Therefore, the main purpose of the present application is to provide a control method and a control device for an electronic fuse to improve computational efficiency and reduce resource requirements.

[0008] Embodiments of the present application provide a control method for an electronic fuse, comprising detecting current passing through the electronic fuse at a time interval; storing current values detected at a plurality of time points; determining a plurality of trip currents corresponding to a plurality of trip times according to the current values, the plurality of trip times being in an exponential relationship with respect to the time interval, comprising (a) for trip times less than or equal to a first value among the plurality of trip times, performing a plurality of arithmetic average operation procedures on the plurality of current values to obtain a first part of the plurality of trip currents corresponding to a current time point according to the exponential relationship of each trip time with respect to the time interval; (b) for trip times greater than the first value among the plurality of trip times, performing a plurality of arithmetic average operation procedures to obtain a second part of the plurality of trip currents corresponding to the current time point based on a second value, the plurality of arithmetic average operation procedures being performed on a plurality of obtained trip currents corresponding to each trip time selected from the first part of the plurality of trip currents corresponding to the current time point and a plurality of first parts of the plurality of trip currents corresponding to a plurality of previous time points; and (c) outputting the first part of the plurality of trip currents and the second part of the plurality of trip currents as the plurality of trip currents; comparing the plurality of trip currents with preset current values corresponding to the plurality of trip times in a preset trip current versus trip time curve to generate a plurality of comparison results; and controlling a state of the electronic fuse according to the plurality of comparison results.

[0009] The application also provides a control device for an electronic fuse. The control device includes a detection module for detecting current passing through the electronic fuse at a time interval; a storage module coupled to the detection module for storing current values detected by the detection module at multiple time points; a trip current determination module coupled to the storage module for determining trip currents corresponding to multiple trip times according to the current values, wherein the multiple trip times are in an exponential relationship with respect to the time interval, and wherein the trip current determination module determines the multiple trip currents by performing the following steps: (a) for trip times less than or equal to a first value among the multiple trip times, performing multiple arithmetic average operations on the current values according to the exponential relationship of each trip time with respect to the time interval to obtain a first part of the multiple trip currents corresponding to a current time point; (b) for trip times greater than the first value among the multiple trip times, performing multiple arithmetic average operations on the first part of the multiple trip currents corresponding to the current time point and multiple first parts of the multiple trip currents corresponding to multiple previous time points to obtain a second part of the multiple trip currents corresponding to the current time point, based on a second value and selected from the first part of the multiple trip currents corresponding to the current time point and the multiple first parts of the multiple trip currents corresponding to the multiple previous time points; and (c) outputting the first part of the multiple trip currents and the second part of the multiple trip currents as the multiple trip currents; multiple comparators coupled to the trip current determination module for comparing the multiple trip currents with preset current values corresponding to the multiple trip times in a preset trip current versus trip time curve; and a switch module coupled to the multiple comparators for controlling a state of the electronic fuse according to comparison results of the multiple comparators. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 A schematic diagram of a trip current versus trip time curve of a fuse.

[0011] Figure 2 A schematic diagram of a power transmission system according to an embodiment of the application.

[0012] Figure 3 A schematic diagram of a control process according to an embodiment of the application.

[0013] Figure 4 A schematic diagram of a determination process according to an embodiment of the application.

[0014] Figure 5 A schematic diagram of an embodiment of determining trip currents according to an embodiment of the application.

[0015] Figure 6 A schematic diagram of a control device according to an embodiment of the application.

[0016] Figure 7This is a schematic diagram of a power transmission system according to Embodiment 1 of the present invention.

[0017] Figure labeling: 10 - travel curve; A0~Ay - travel current; 2 - power transmission system; 20 - power supply; 22 - load; 24 - wiring harness; 26 - electronic fuse; 28 - control device; SW - switching signal; Ir - current; 30 - control flow; 40 - judgment flow; 300~312, 400~408 - steps; t0 - current time point; 600 - detection module; 602 - storage module; 604 - travel current judgment module; 606 - switch module; D1~Da - storage unit; CMP_0~CMP_y - comparator; 7 - power transmission system; 70 - input protection module; 72 - output protection module; 74 - control device; PWR_1~PWR_n - power supply; EF1_1~EF1_n, EF2_1~EF2_n - electronic fuse; LD_1~LD_n - load. Detailed Implementation

[0018] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the trip curve 10, which shows the trip current versus trip time of a fuse. Figure 1 This is a logarithmic coordinate system that describes the overcurrent conditions a fuse can withstand at different travel times, i.e., the current it can withstand in different time windows. The vertical axis represents the travel current, and the horizontal axis represents the logarithm of the travel time T, base 2 (log2(T)). For example, A0 represents the current that a fuse can withstand at travel time T equal to (2... 0 =) The average current that a fuse can withstand within 1 millisecond (ms). If a current exceeding the average current value A0 passes through the fuse within 1 millisecond, the fuse will blow; and so on. Ay represents the current during the travel time T equals 2... y The average current that a fuse can withstand within milliseconds, if within 2... y Within milliseconds, if a fuse withstands a current exceeding its average current value Ay, it will blow. In other words, a large current in a short period will cause the fuse to blow quickly, while a smaller overcurrent can be withstood for a longer period. This avoids unnecessary fuse blowing caused by short-duration pulse currents and also ensures that the heat accumulated by low currents over a long period can effectively blow the fuse.

[0019] Depend on Figure 1 As shown in the travel curve 10, a fuse needs to have different fusing characteristics depending on the travel time (time window) to provide more precise protection at different time scales. To achieve this with an electronic fuse... Figure 1The curve of the stroke current versus the stroke time requires a large amount of computing resources and a complex hardware circuit. To this end, the present application uses a dual-mode to determine the stroke current so as to reduce the requirement of the computing resources and the complexity of the circuit. Please refer to Figure 2 , Figure 2 Fig. 1 is a schematic diagram of a power transmission system 2 according to an embodiment of the present application. The power transmission system 2 transmits power from a power supply 20 to a load 22 via a wiring harness 24, which includes an electronic fuse 26 and a control device 28. The power supply 20 can be a linear power supply, a switching mode power supply, a programmable power supply, a high voltage power supply, a battery supply, etc., and is not limited thereto. The load 22 can be any hardware device driven by power, for example, if applied to the automotive field, the load 22 can be a car light, an air conditioning system, a power window, a wiper, etc., and is not limited thereto. The electronic fuse 26 is electrically connected between the power supply 20 and the wiring harness 24, which has different turn-off characteristics corresponding to different stroke times, and can be reset to restore the conduction. The control device 28 is electrically connected to the electronic fuse 26, which outputs a switching signal SW according to the current Ir passing through the electronic fuse 26, so as to control the state of the electronic fuse 26, so that the operating characteristics thereof can reach or approach the stroke curve 10 shown in Fig. 1. In the embodiment of the present application, the "controlling the state of the electronic fuse 26" means controlling the electronic fuse 26 to be in the conduction state or the turn-off state. In other words, the control device 28 outputs the switching signal SW to turn on or turn off the electronic fuse 26 according to the current Ir. Figure 1

[0020] Specifically, the operating mode of the control device 28 can be summarized as a control flow 30, as shown in Fig. 2. The control flow 30 includes the following steps: Figure 3

[0021] Step 300: Start.

[0022] Step 302: Detect the current passing through the electronic fuse 26 at a time interval.

[0023] Step 304: Store a plurality of current values detected at a plurality of time points.

[0024] Step 306: Determine a plurality of stroke currents corresponding to a plurality of stroke times according to the plurality of current values, the plurality of stroke times being in an exponential relationship with respect to the time interval.

[0025] Step 308: Compare the plurality of stroke currents with a plurality of preset current values corresponding to the plurality of stroke times in a preset stroke current versus stroke time curve (hereinafter referred to as a preset stroke curve) to generate a plurality of comparison results.

[0026] Step 310: Control the state of the electronic fuse 26 according to the plurality of comparison results.​​

[0027] Step 312: End.

[0028] According to the control flow 30, the control device 28 detects or samples the current passing through the electronic fuse 26 at fixed time intervals (step 302), and stores the detected (or sampled) current values to form a set of current data corresponding to a plurality of time points (step 304); where the time interval is preferably the response time of the electronic fuse 26, for example, 1 millisecond, and the way of storing the detected current values can be a shift register way, i.e., each time the newest sampled current value data replaces the oldest current value data, but not limited thereto. Next, the control device 28 determines a plurality of trip currents corresponding to a plurality of trip times according to the stored plurality of current values (step 306); it is worth noting that there is an exponential relationship between the trip time and the detection time interval. After obtaining the trip current data, the control device 28 compares it with the corresponding preset current values on the preset trip curve (for example, the trip curve 10 of Figure 1 ). Specifically, the control device 28 compares the actually measured trip current with the current value corresponding to the same trip time on the preset trip curve, thereby obtaining a plurality of comparison results corresponding to a plurality of trip times. In the embodiment of the present application, the preset trip curve can be determined according to the characteristics (for example, the ignition characteristics) of the wire harness 24. Finally, the control device 28 determines how to control the state of the electronic fuse 26 according to these comparison results (step 310). The preset trip curve is set according to the application scenario, for example, the ignition characteristics of the wire harness 24 or the characteristics of the electronic fuse 26 entering the over temperature protection. Therefore, if a comparison result shows that the trip current is greater than the corresponding current value on the preset trip curve, it means that the current may cause the wire harness 24 to ignite or the electronic fuse 26 to enter the over temperature protection, and then the control device 28 can turn off the electronic fuse 26 to avoid causing the wire harness 24 to overheat or the electronic fuse 26 to overload.

[0029] In one embodiment, the current passing through the electronic fuse 26 is detected by the control device 28. In another embodiment, the current passing through the electronic fuse 26 is detected by the internal sensing element of the electronic fuse 26 and a corresponding sensing current signal is generated, and the control device 28 samples the sensing current signal to obtain the current value representing the current passing through the electronic fuse 26.

[0030] Since the trip time corresponding to each trip current is exponentially related to the response time of the electronic fuse 26, the control device 28 can control the electronic fuse 26 to respond to a large current at a short trip time and to respond to the heat accumulated by a small current at a long trip time. In other words, the control device 28 needs to calculate the trip currents at different trip times according to the current detection results at long times. In this case, in order to reduce the requirements for computing resources and storage capacity, the embodiment of the present application further adopts a judgment procedure 40 to implement step 306. As shown in Figure 4 the judgment procedure 40 includes the following steps:

[0031] Step 400: Start.

[0032] Step 402: For the trip times less than or equal to a first value among the plurality of trip times, perform a plurality of arithmetic average operation procedures on the plurality of current values according to the exponential relationship of each trip time with respect to the time interval to obtain a first part of the plurality of trip currents corresponding to a current time point.

[0033] Step 404: For the trip times greater than the first value among the plurality of trip times, based on a second value, select the obtained trip currents corresponding to each trip time from the first part of the plurality of trip currents corresponding to the current time point and a plurality of first parts of the plurality of trip currents corresponding to a plurality of previous time points to perform a plurality of arithmetic average operation procedures to obtain a second part of the plurality of trip currents corresponding to the current time point.

[0034] Step 406: Output the first part of the trip currents and the second part of the trip currents as the plurality of trip currents.

[0035] Step 408: End.

[0036] In short, the judgment procedure 40 divides the trip currents into two parts for judgment. The first part corresponds to the trip times less than or equal to the first value among the trip times, and is obtained by performing a plurality of arithmetic average operation procedures on the stored current values according to the exponential relationship of each trip time with respect to the time interval (step 402). The second part corresponds to the trip times greater than the first value among the trip times, and is obtained by performing a plurality of arithmetic average operation procedures on the trip currents calculated at the current time point and the previous time points (through step 402) with a second value (step 404). In other words, the arithmetic average operation basis of the first part of the trip currents changes according to the exponential relationship of the trip times, while the arithmetic average operation basis (the second value) of the second part of the trip currents does not change with the trip times and can be a constant value. In this case, the computing complexity and cost can be greatly reduced, and the reduction of the computing complexity and cost is more obvious as the trip times increase.

[0037] In detail, let's assume S a (x) represents the a-th current value stored (or sampled) by control device 28 at the x-th time interval from the current time point (t0), C T (x) represents the travel current at the x-th time interval from the current point in time, with a travel time of T. For example, S1(1), S2(1), ..., S 64 (1) This represents the first to 64th current values ​​stored (or sampled) by the control device 28 at the first time interval from the current point in time; since the control device 28 replaces the oldest current value data with the latest sampled current value data each time it samples, in other words, at the next (latest) sample, the S value of the previous sampled current value will be replaced by the latest sampled current value data. 64 (1) will be removed, while the S sampled in the previous sampling 63 (1) Become the new S 64 (1) S from the previous sampling 62 (1) Become the new S 63 (1), and so on, the previously sampled S1(1) becomes the new S2(1), and the latest sampled current value becomes the new S1(1). Furthermore, the first value is related to or depends on the number of current values ​​that the control device 28 can store (or sample), while the second value is related to the number of current values ​​that need to be referenced when calculating the second part of the stroke current. The first and second values ​​can be equal, related, or different. For simplicity, it is assumed that the first and second values ​​are equal, both being 2. P According to step 402, the first part of the stroke current... for:

[0038] And n≤p, x=1;

[0039] According to step 404, the second part of the stroke current... for:

[0040] And p <m。

[0041] For example, taking a trip time of 5 PM and a sampling time interval of 1 millisecond (ms) as an example, that is, T = 2... 0 ,2 1 ,2 2 , ..., 2 16 (ms), assuming the number of current values ​​that the control device 28 can store is 64, that is, the current values ​​stored by the control device 28 in the first time interval at the current time point are S1(1), S2(1), ..., S 64 (1), and the first value is 2 P =64, or p=6. According to Equation 1, the first part of the stroke current can be obtained. for:

[0042] T=2 0 n=0,

[0043] T=2 1 n=1,

[0044] T=2 2 n=2,

[0045] …

[0046] T=2 6 n=6

[0047] Specifically, for values ​​less than or equal to the first value 2 P The travel time T, i.e., T = 2 0 ,2 1 ,2 2 , ..., 2 6 Equation 1 or step 402 is based on the exponential relationship between each travel time and the time interval (i.e., 2). n This determines the number of current values ​​used to calculate the stroke current corresponding to each stroke time (e.g., calculating...). At that time, the number of reference current values ​​is 2; calculation At that time, the number of current values ​​to be referenced is 4). Then, Equation 1 or step 402 uses the stored current values ​​(i.e., S1(1), S2(1), ..., S...). 64 (1) Select the current values ​​corresponding to each stroke time (e.g., calculate the current value). When S1(1) and S2(1) are selected, calculate... When selecting S1(1), S2(1), S3(1), and S4(1), an arithmetic average calculation program is performed on the current values ​​corresponding to each stroke time (e.g., ...). ), to obtain the first portion of the travel current corresponding to the current time point. Furthermore, since each sampling replaces the oldest current value with the most recently sampled current value, selecting current values ​​to calculate the travel current can be understood as starting from the current time point and selecting current values ​​equal to the number of previously determined current values ​​from previous time points. For example, when calculating... When the number of current values ​​to be referenced is 4, then Equation 1 or step 402 selects a total of 4 current values ​​(equal to the number of current values) from the current time point (corresponding to S1(1)) to the previous time points (corresponding to S2(1), S3(1), S4(1)).

[0048] After the first part of the travel current is calculated, the second part of the travel current is calculated by Equation 2 or step 404. In this example, 17 points of travel time are needed, and it is known that 6 < m < 17. According to Equation 2, the second part of the travel current is T = 2

[0049] T = 2 7 , m = 7,

[0050] T = 2 8 , m = 8,

[0051] …

[0052] T = 2 16 , m = 16,

[0053] In particular, for travel times T greater than the first value 2 P , i.e., T = 2 7 , 2 8 , 2 9 , …, 2 16 , Equation 2 or step 404 obtains the second part of the travel current by taking the difference (i.e., 2 m ) between each travel time (i.e., 2 P ) and the first value 2 (m-p) , and then taking the arithmetic average of the obtained travel currents corresponding to each travel time and related to the second value (i.e., 2 P ) from the first part of the travel current corresponding to the current time point (i.e., x = 1) and the first parts of the travel currents corresponding to the previous time points (i.e., x = 2, 3, …, 64). For example, when calculating , T = 2 7 , the difference between the travel time and the first value 2 6 is 2 1 , and thus the first part of the travel current to be referenced when calculating is In detail, the first part of the travel current corresponding to the current time point (i.e., x = 1) and the obtained first parts of the travel currents related to the second value 2 6 , i.e., the first parts of the travel currents x = 2, 3, …, 64 are referenced when calculating . Then, the arithmetic average of these travel currents with the second value 2 6 is calculated, and the travel current By analogy, the second part of the stroke current can be obtained.

[0054] Furthermore, it should be noted that in this example, when calculating the second part of the travel current... When, Equation 2 or step 404 refers to the stroke current in the second part. However, as can be seen from the above derivation, The calculation is based on the first part of the stroke current. Therefore, broadly speaking, the second part of the stroke current The calculation is still based on the first part of the travel current. Therefore, in summary, the embodiment of the present invention performs an arithmetic average operation on the stored current values ​​to determine the first part of the travel current, and then performs an arithmetic average operation on the calculated first part of the travel current to determine the second part of the travel current. In this way, the calculation of all travel currents at the current time point can be completed (step 406).

[0055] As described above, after determining the number of travel times, the first value is related to the ratio of the first portion of the travel current to the second portion of the travel current. For example, in the aforementioned embodiment, the number of travel times is 17 points, and the first value is 2. 6 It can be seen that the first part of the stroke current corresponds to the stroke time 2. 0 Up to 2 6 The second part of the stroke current corresponds to the stroke time 2. 7 Up to 2 16 At the same time, the first value is also related to the number of current values ​​that need to be referenced when calculating the first part of the stroke current, which in the aforementioned embodiment are S1(1), S2(1), ..., S 64 (1). In this case, a person skilled in the art can determine the first value according to the system requirements, for example, based on the storage space of the control device 28; or, the first value can be determined first, and then the storage space of the control device 28 can be designed or adjusted. Furthermore, as shown in Equation 1, when calculating the first portion of the stroke current, the reference 2 for the arithmetic mean of each stroke current is... n It changes with the travel time, for example, in calculations. At that time, the arithmetic mean benchmark was 2, while the calculation At that time, the arithmetic mean baseline is 4. Therefore, when determining the first value, it is also necessary to consider that as the stroke current increases, the calculation requirements of the control device 28 will also increase exponentially.

[0056] On the other hand, as can be seen from Equation 2, when calculating the second part of the stroke current, the first value (i.e., the numerator of Equation 2) is... 2 in P The first part of the stroke current needs to be referenced (forward) for each stroke time, while the second value (i.e., the summation symbol in the numerator of Equation 2 and the 2 in the denominator) determines which stroke currents need to be referenced (forward).P ) is the number of the first partial trip currents to be referenced for determining the arithmetic mean reference and the (current and previous) first partial trip currents. For example, in calculating , according to the difference between the trip time and the first value (i.e. 2 (m-p) = (i.e. 2 1 ), the first partial trip currents are to be referenced and according to the second value, the first partial trip currents are to be referenced and the arithmetic mean reference is 64. Furthermore, from the equation 2, it can be seen that the arithmetic mean reference for all the second partial trip currents is 64, in other words, different from the arithmetic mean reference 2 n for calculating the first partial trip currents. As the trip time increases, the required computing resources for the second partial trip currents are linearly increased, which can effectively reduce the operation demand.

[0057] The above calculation and derivation process can be represented in a graphical manner, as shown in Figure 5 , which can clearly show that the arithmetic mean reference for calculating the first partial trip currents is changed with the trip time, while the arithmetic mean reference for calculating the second partial trip currents is fixed.

[0058] It should be noted that the judgment flow 40 of Figure 4 is an embodiment of the present application, and those skilled in the art with ordinary knowledge can make different modifications without being limited thereto. For example, in addition to adjusting the first value according to the needs of the system, the second value can also be different from the first value, or dynamically adjusted. For example, in an embodiment, the control device 28 can adjust the size of the second value according to the changes of the operation resources. Furthermore, the aforementioned embodiment divides the trip currents to be calculated into two parts, in fact, the trip currents to be calculated can also be divided into three or more parts. For example, a third partial trip current can be set to adopt a different second value, or the third partial trip current can be defined to adopt the second partial trip current as the basis for calculation, which are all within the scope of the present application.

[0059] Therefore, by Figure 4The first part is an arithmetic average operation according to the stored (sampled) current value, and the second part is an arithmetic average operation according to the operation result of the first part. Meanwhile, the calculation basis of the first part of the travel current is changed according to the travel time, and the calculation basis of the second part of the travel current is not changed with the travel time. Therefore, the calculation complexity and cost can be greatly reduced. In addition, the travel time is exponentially related to the time interval of the sampling, that is, the closer to the current time point, the more frequently the travel current is judged. It can be ensured that the short-time large current and the long-time small current can be simultaneously reacted, so that the unnecessary shutdown of the electronic fuse 26 caused by the short-time pulse current can be avoided, and it can be ensured that the long-time low current will not damage the wire harness 24 or cause the electronic fuse 26 to be overloaded.

[0060] After the travel current is judged by the judging flow 40 or the formula 1 and the formula 2, the control flow 30 is returned, and the control device 28 can compare the judged travel current with the preset current value in the preset travel curve (step 308), and control the state of the electronic fuse 26 according to the comparison (step 310). Therefore, by the control flow 30, the control device 28 can control the electronic fuse 26 to be turned on or turned off according to the current passing through the electronic fuse 26, so as to avoid the wire harness 24 from being burned or the electronic fuse 26 from being damaged. It should be noted that, Figure 2 The power transmission system 2 is an embodiment of the present application, and those skilled in the art with ordinary skill can make different modifications according to the power transmission system 2 without being limited thereto. For example, please refer to Figure 6 , Figure 6A schematic diagram of an embodiment of the control device 28. The control device 28 comprises a detection module 600, a storage module 602, a trip current determination module 604, comparators CMP_0 to CMP_y, and a switching module 606. In this embodiment, the detection module 600 is configured to detect the current Ir passing through the electronic fuse 26 at a time interval, for example, it can be a combination of a resistor and an analog-to-digital converter, where the resistor converts the current into a voltage signal, and the analog-to-digital converter samples to convert the current value into a digital form. In other embodiments, the electronic fuse 26 detects the current passing through the electronic fuse 26 by an internal sensing element and generates a corresponding sensing current signal, and the detection module 600 samples the sensing current signal at a time interval to obtain the current value representing the current passing through the electronic fuse 26. The storage module 602 is coupled to the detection module 600 and comprises storage units D1 to Da, which preferably store the current values detected by the detection module 600 at multiple time points in a shift register manner, i.e., each time a new sampled current value data replaces the oldest current value data. The trip current determination module 604 is coupled to the storage module 602 and is configured to determine the trip currents C T (x) corresponding to the multiple trip times based on the current values stored in the storage module 602. Specifically, the trip current determination module 604 can perform the determination process 40 or equation 1, 2 and their derivative variations, i.e., the trip currents are divided into two (or more) parts for calculation, the first part is an arithmetic mean calculation based on the current values stored in the storage module 602, and the second part is an arithmetic mean calculation based on the calculation result of the first part. The comparators CMP_0 to CMP_y are coupled to the trip current determination module 604 and are respectively configured to compare the trip currents C T (x) with the preset current values A0 to Ay corresponding to the trip times in the preset trip curve to generate corresponding comparison results. The switching module 606 is coupled to the comparators CMP_0 to CMP_y and is configured to output a switching signal SW based on the comparison results of the comparators CMP_0 to CMP_y to control the state of the electronic fuse 26.

[0061] In an embodiment, when the comparison result of any one of the comparators CMP_0 to CMP_y indicates that the corresponding trip current is greater than the corresponding preset current value in the preset trip curve, the switching module 606 outputs the switching signal SW to control the electronic fuse 26 to enter the off state, in the case that the electronic fuse 26 is in the on state. For example, when the comparison result of the comparator CMP_1 indicates that the trip current C When the trip current is greater than the preset current value Ap, the switch module 606 outputs a switching signal SW to control the electronic fuse 26 to enter the off state. According to the above, the condition for controlling the electronic fuse 26 to enter the off state is that the comparison result indicating that the corresponding trip current is greater than the corresponding preset current value in the preset trip curve is equal to 1.

[0062] The detailed operation of the trip current judgment module 604 can refer to the descriptions of the judgment flow 40 and formulas 1 and 2. It is noted that the first value 2 P The number a of the storage units D1-Da can be related to the number y of the comparators CMP_0-CMP_y, which are related to the trip current versus trip time curve. Therefore, the designer can adjust the implementation of the control device 28 according to the system requirements, without being limited thereto.

[0063] In addition, Figure 2 The power transmission system 2 only includes a single electronic fuse. However, a person with ordinary skill in the art can derive multiple electronic fuses as appropriate and share some components as appropriate. For example, please refer to Figure 7 , Figure 7Fig. 1 shows a schematic diagram of a power delivery system 7 according to an embodiment of the present application. The power delivery system 7 is used to deliver power from power supplies PWR_1-PWR_n to loads LD_1-LD_n, and includes an input protection module 70, an output protection module 72, and a control device 74. The power supplies PWR_1-PWR_n can be linear power supplies, switching mode power supplies, programmable power supplies, high voltage power supplies, battery supplies, etc., and are not limited thereto. The loads LD_1-LD_n can be any hardware devices powered by the power supplies, for example, if applied to the automotive field, the loads LD_1-LD_n can be vehicle lights, air conditioning systems, power windows, wipers, etc., and are not limited thereto. The input protection module 70 and the output protection module 72 form a power delivery network from the power supplies PWR_1-PWR_n to the loads LD_1-LD_n, and are respectively composed of electronic fuses EF1_1-EF1_n and EF2_1-EF2_n, which can have different turn-off characteristics according to different trip times, and can be reset to restore conduction. The control device 74 is electrically connected to the electronic fuses EF1_1-EF1_n and EF2_1-EF2_n, and is used to control the state of the electronic fuses EF1_1-EF1_n and EF2_1-EF2_n (i.e., control the electronic fuses EF1_1-EF1_n and EF2_1-EF2_n to be in a conduction state or a turn-off state) according to the current passing through the electronic fuses EF1_1-EF1_n and EF2_1-EF2_n. The control method of the control device 74 for each electronic fuse can refer to the description of the control device 28 described above, so as to achieve or approach the Figure 1 the trip current versus trip time curve shown.

[0064] Figure 7 The power delivery system 7 can implement a power network, such as a power distribution module of a vehicle. When applied to a vehicle, the control device 74 of the embodiment of the present application can timely turn off a specific electronic fuse to avoid overheating of the corresponding wiring harness or overloading of the electronic fuse. In addition, for vehicle applications, in addition to properly calculating the trip current, the characteristics of the wiring harness that can be affected by the use environment also need to be considered, and for this case, the trip current versus trip time curve (e.g., the aforementioned preset trip curve) can be updated to meet the actual use requirements.

[0065] In detail, with the continuous progress of vehicle technology, the complexity of vehicle electronic systems is increasing. However, the traditional method of protecting the wiring harness of the vehicle has been unable to meet the safety requirements of modern vehicles, especially how to dynamically adjust the protection parameters according to the aging condition of the wiring harness. Generally speaking, the relationship between the aging speed of the wire and the temperature can be represented by the Arrhenius equation:

[0066]

[0067] wherein,

[0068] t life : expected lifetime of the wire (time);

[0069] A: constant, related to material properties;

[0070] E a : activation energy (unit: Joule / mole);

[0071] K b : Boltzmann constant (1.38 x 10-23J / K);

[0072] T: operating temperature of the wire (absolute temperature, Kelvin).

[0073] As can be seen from the equation, the aging of the wire is closely related to the ambient temperature and the temperature generated by the current flowing through it. The aging problem of the wire harness cannot be ignored due to its long-term exposure to high-temperature environments during driving and under the scorching sun when parked. In this regard, the current value of each load at a specific speed and ambient temperature can be recorded after the vehicle is shipped, for example, it can be recorded and stored by the microcontroller of the power distribution module, and these data can be transmitted back to the manufacturer's server when the vehicle is regularly maintained or uploaded through the network, as a reference for judging the harness or load problem in the future. For example, as the vehicle is used, the wire harness will gradually age due to usage frequency and environmental factors, and the aging process will reduce the current-carrying capacity of the wire harness, increasing the safety risk. In this regard, the embodiments of the present application can evaluate the aging degree of the wire harness according to the driving mileage (such as 10km / 20km / 30km) or other related parameters, and then multiply the current value in the preset trip curve (for example, the preset trip curve used for comparison operation in step 308) used to control the electronic fuse by a derating factor, thereby updating the preset trip curve stored by the vehicle through over-the-air technology or wired connection method (such as through controller area network).

[0074] It should be noted that in order to achieve the above updating operation, the power transmission system 7 should have wired or wireless connection function, and can appropriately update the current-time curve stored by the control device 74. Such derivative changes should be familiar to those skilled in the art with ordinary knowledge, and therefore will not be described in detail.

[0075] In short, for automotive applications, the embodiments of the present application can improve the safety and reliability of automotive electronic systems by monitoring the wire harness state in real time and dynamically adjusting the protection parameters, not only can prevent potential safety hazards, but also can provide important decision basis for vehicle maintenance.

[0076] In summary, for the control of electronic fuse, the prior art has high computational complexity, requires a large amount of hardware resources, and lacks flexibility, and is difficult to adapt to dynamically changing working environments and load characteristics. In contrast, the present application can provide accurate overcurrent protection on various time scales, while having the characteristics of high computational efficiency, low resource demand, and strong flexibility, and can be updated and adjusted according to actual use.

[0077] The above description is only the preferred embodiment of the present application, and any equivalent changes and modifications made according to the claims of the present application shall be within the scope of the present application.

Claims

1. A control method for an electronic fuse, characterized in that, Includes: The current passing through the electronic fuse is detected at time intervals; Store multiple current values ​​detected at multiple time points; Based on these multiple current values, multiple stroke currents corresponding to multiple stroke times are determined. These multiple stroke times have an exponential relationship with the time interval and include: (a) For a travel time less than or equal to a first value among the plurality of travel times, perform a plurality of arithmetic average operations on the plurality of current values ​​according to the exponential relationship between each travel time and the time interval, so as to obtain a first portion of the travel current among the plurality of travel currents corresponding to a current point in time. (b) For the travel time greater than the first value among the multiple travel times, based on a second value, multiple arithmetic average operations are performed on multiple travel currents corresponding to each travel time from the first part of the travel current corresponding to the current time and the multiple first part of the travel current corresponding to multiple previous times, so as to obtain a second part of the travel current among the multiple travel currents corresponding to the current time. as well as (c) Output the first part of the stroke current and the second part of the stroke current as the multiple stroke currents; The multiple stroke currents are compared with a preset current value corresponding to the multiple stroke times in the stroke current-to-stroke time curve to generate multiple comparison results; as well as Based on these multiple comparison results, the state of the electronic fuse is controlled.

2. The control method as described in claim 1, characterized in that, Step (a) includes: For each travel time less than or equal to the first value, the number of current values ​​used to calculate the travel current corresponding to each travel time is determined based on the exponential relationship between each travel time and the time interval; and The current values ​​corresponding to each travel time are selected from the multiple current values, and an arithmetic average calculation is performed on the current values ​​corresponding to each travel time to obtain the first part of the travel current corresponding to the current point in time.

3. The control method as described in claim 1, characterized in that, Step (b) includes: For any travel time greater than the first value among the plurality of travel times, based on the difference between each travel time and the first value, the plurality of previously obtained travel currents corresponding to each travel time and related to the second value are obtained from the first portion of the travel current corresponding to the current time and the plurality of first portion of the travel current corresponding to the plurality of previous times; and An arithmetic average calculation procedure is performed on the plurality of acquired travel currents corresponding to each travel time and related to the second value to obtain the second portion of the travel current.

4. The control method as described in claim 1, characterized in that, The electronic fuse is electrically connected to a wire harness, and the preset travel current versus travel time curve is related to the ignition characteristics of the wire harness.

5. The control method as described in claim 1, characterized in that, It also includes updating the travel current to travel time curve, wherein the electronic fuse is electrically connected to a wire harness, and the update of the travel current to travel time curve is based on the usage of the wire harness.

6. A control device for an electronic fuse, characterized in that, Includes: A detection module is used to detect the current passing through the electronic fuse at time intervals; A storage module, coupled to the detection module, is used to store multiple current values ​​detected by the detection module at multiple points in time; A stroke current determination module, coupled to the storage module, is used to determine multiple stroke currents corresponding to multiple stroke times based on the multiple current values, wherein the multiple stroke times have an exponential relationship with the time interval, and wherein the stroke current determination module performs the following steps to determine the multiple stroke currents: (a) For a travel time less than or equal to a first value among the plurality of travel times, perform a plurality of arithmetic average operations on the plurality of current values ​​according to the exponential relationship between each travel time and the time interval, so as to obtain a first portion of the travel current among the plurality of travel currents corresponding to a current point in time. (b) For a travel time greater than the first value among the plurality of travel times, based on a second value, a plurality of arithmetic average operations are performed on the plurality of travel currents corresponding to each travel time, selected from the first portion of travel current corresponding to the current time and the plurality of first portion of travel current corresponding to a plurality of previous time points, to obtain a second portion of travel current among the plurality of travel currents corresponding to the current time; and (c) Output the first part of the stroke current and the second part of the stroke current as the multiple stroke currents; Multiple comparators, coupled to the travel current determination module, are used to compare the multiple travel currents with a preset current value corresponding to the multiple travel times in a preset travel current-to-time curve; and A switching module, coupled to the plurality of comparators, is used to control the state of the electronic fuse based on the comparison results of the plurality of comparators.

7. The control device as described in claim 6, characterized in that, Step (a) includes: For each travel time less than or equal to the first value, the number of current values ​​used to calculate the travel current corresponding to each travel time is determined based on the exponential relationship between each travel time and the time interval; and The current values ​​corresponding to each travel time are selected from the multiple current values, and an arithmetic average calculation is performed on the current values ​​corresponding to each travel time to obtain the first part of the travel current corresponding to the current point in time.

8. The control device as described in claim 6, characterized in that, Step (b) includes: For any travel time greater than the first value among the plurality of travel times, based on the difference between each travel time and the first value, the plurality of previously obtained travel currents corresponding to each travel time and related to the second value are obtained from the first portion of the travel current corresponding to the current time and the plurality of first portion of the travel current corresponding to the plurality of previous times; and An arithmetic average calculation procedure is performed on the plurality of acquired travel currents corresponding to each travel time and related to the second value to obtain the second portion of the travel current.

9. The control device as described in claim 6, characterized in that, The electronic fuse is electrically connected to a wire harness, and the preset travel current versus travel time curve is related to the ignition characteristics of the wire harness.

10. The control device as claimed in claim 6, characterized in that, It also includes an update module for updating the travel current versus travel time curve, wherein the electronic fuse is electrically connected to a wire harness, and the update module updates the travel current versus travel time curve according to the usage of the wire harness.

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