Over-current protection method, device, equipment and medium

Abstract

The invention discloses an overcurrent protection method. The method comprises the following steps: acquiring overcurrent protection influence factors, wherein the overcurrent protection influence factors comprise temperature drift and voltage fluctuation; dynamic compensation is carried out on the basic overcurrent threshold value according to the overcurrent protection influence factors, and an overcurrent protection threshold value is obtained; the basic overcurrent threshold value is determined based on a wire harness impedance model; and under the condition that the real-time current value is greater than the overcurrent protection threshold value, triggering an overcurrent protection action so as to realize overcurrent protection of the protected object. Through dynamic compensation of the basic overcurrent threshold and integration of multi-dimensional influence factors such as temperature drift and voltage fluctuation, threshold deviation caused by the temperature drift and the voltage fluctuation is effectively eliminated, false triggering or protection failure is avoided, and the method has the advantages of improving overcurrent protection precision and system stability.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronic protection, and in particular to an overcurrent protection method, device, equipment and medium. Background Art

[0002] Existing VDS (Voltage Drain to Source) overcurrent protection systems utilize a fixed current threshold design, which exhibits significant flaws. Under transient operating conditions, such as a motor stall, the system generates short-term peak currents. These transient current fluctuations under normal operating conditions can easily be misinterpreted by the fixed threshold as short-circuit faults, causing the protection device to malfunction. These technical flaws manifest themselves in practical system malfunctions. For example, the one-touch folding function of a car seat can fail due to erroneous triggering of the overcurrent protection. Furthermore, system reliability is reduced, and occasional faults cannot be effectively suppressed by static thresholds, often requiring manual intervention for reset or repair, severely impacting user experience and system stability. Summary of the Invention

[0003] In view of the above-mentioned shortcomings of the prior art, the present invention provides an overcurrent protection method, device, equipment and medium to solve at least one defect in the prior art.

[0004] The present invention provides an overcurrent protection method, which includes: Obtaining overcurrent protection influencing factors; the overcurrent protection influencing factors include temperature drift and voltage fluctuation; Dynamically compensating a basic overcurrent threshold according to the overcurrent protection influencing factors to obtain an overcurrent protection threshold; the basic overcurrent threshold is determined based on a harness impedance model; When the real-time current value is greater than the overcurrent protection threshold, the overcurrent protection action is triggered to implement overcurrent protection for the protected object.

[0005] In one embodiment of the present invention, the overcurrent protection method further includes: Get the real-time junction temperature of the power MOS tube; Determining a first on-resistance corresponding to the real-time junction temperature based on a correlation between the real-time junction temperature and a preset correlation, wherein the correlation represents a mapping relationship between the on-resistance and the junction temperature of the power MOS tube; When the real-time junction temperature is not equal to the set temperature threshold, the first on-resistance is compensated and corrected to obtain a second on-resistance, so that the overcurrent protection threshold is kept constant when the temperature changes through the second on-resistance.

[0006] In one embodiment of the present invention, the association relationship includes: a discrete data table and / or a polynomial function model; wherein, When constructing the discrete data table, the discrete data table is optimized by an optimization method, and the optimization method includes at least one of the following: Use linear interpolation to calculate the on-resistance corresponding to the real-time junction temperature between adjacent temperature points, merge the intervals where the on-resistance change rate of adjacent temperature points is less than the set threshold, and configure the temperature sampling point density in the nonlinear interval to be higher than that in the linear interval; When constructing the polynomial function model, the root mean square error of the fitting result is calculated, and the fitting quality is evaluated by the root mean square error.

[0007] In one embodiment of the present invention, the overcurrent protection method further includes: Matching the real-time junction temperature of the power MOS tube with a preset temperature range set to obtain the preset temperature range to which the real-time junction temperature belongs; The overcurrent protection threshold is dynamically modified according to the preset temperature range to generate an optimized overcurrent protection threshold.

[0008] In one embodiment of the present invention, the overcurrent protection method further includes: A hysteresis threshold is set at the boundary of the temperature interval. When the temperature change crosses the boundary of an adjacent temperature interval, if the temperature change is greater than the hysteresis threshold, the overcurrent protection threshold is switched from the overcurrent protection threshold corresponding to the first temperature interval to the overcurrent protection threshold corresponding to the second temperature interval.

[0009] In one embodiment of the present invention, dynamically compensating the basic overcurrent threshold according to the overcurrent protection influencing factors to obtain the overcurrent protection threshold includes: Obtaining a temperature drift compensation term and a voltage fluctuation compensation term; wherein the temperature drift compensation term is determined based on a difference between a real-time junction temperature of the power MOS tube and a reference junction temperature and a temperature compensation coefficient, and the voltage fluctuation compensation term is determined based on a difference between a real-time supply voltage and a reference supply voltage and a voltage fluctuation compensation coefficient; Obtaining a current compensation value based on the temperature drift compensation term and the voltage fluctuation compensation term; The basic overcurrent threshold is compensated by the current compensation value to obtain an overcurrent protection threshold.

[0010] In one embodiment of the present invention, the overcurrent protection influencing factors further include: load characteristics, and the load characteristics are determined based on at least one of the following: Motor current, motor output shaft speed; The dynamically compensating the basic overcurrent threshold according to the overcurrent protection influencing factors to obtain the overcurrent protection threshold includes: Obtaining a characteristic compensation item, wherein the characteristic compensation item is determined based on a load characteristic and a load characteristic compensation coefficient; Obtaining a current compensation value based on the characteristic compensation item, the temperature drift compensation item, and the voltage fluctuation compensation item; The basic overcurrent threshold is compensated by the current compensation value to obtain an overcurrent protection threshold.

[0011] The present invention provides an overcurrent protection device, comprising: A factor acquisition module is used to obtain overcurrent protection influencing factors; the overcurrent protection influencing factors include temperature drift and voltage fluctuation; a current adjustment module, configured to dynamically compensate a basic overcurrent threshold according to the overcurrent protection influencing factors to obtain a dynamically adjusted overcurrent protection threshold; the basic overcurrent threshold is determined based on a harness impedance model; The overcurrent trigger module is used to trigger the overcurrent protection action when the real-time current value is greater than the overcurrent protection threshold, so as to achieve overcurrent protection for the protected object.

[0012] The present invention provides an overcurrent protection device, comprising: one or more processors; and One or more machine-readable media having instructions stored thereon, when executed by the one or more processors, cause the device to perform the overcurrent protection method.

[0013] The present invention provides a machine-readable medium having instructions stored thereon, which, when executed by one or more processors, enables the processors to execute the overcurrent protection method.

[0014] Beneficial effects of the present invention: The present invention provides an overcurrent protection method, comprising: obtaining overcurrent protection influencing factors; the overcurrent protection influencing factors including temperature drift and voltage fluctuation; dynamically compensating a basic overcurrent threshold based on the overcurrent protection influencing factors to obtain an overcurrent protection threshold; the basic overcurrent threshold is determined based on a wiring harness impedance model; and when the real-time current value is greater than the overcurrent protection threshold, triggering an overcurrent protection action to achieve overcurrent protection for the protected object. By dynamically compensating the basic overcurrent threshold and integrating multi-dimensional influencing factors such as temperature drift and voltage fluctuation, the present invention effectively eliminates threshold deviations caused by temperature drift and voltage fluctuation, avoids false triggering or protection failure, and has the advantages of improving overcurrent protection accuracy and system stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are incorporated into and constitute a part of this specification, illustrate embodiments consistent with the present invention, and together with the description, serve to explain the principles of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and it is clear that those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0016] In the attached figure: Figure 1 This is a flow chart of an overcurrent protection method according to an embodiment of the present invention; Figure 2 This is a flow chart of an overcurrent protection method according to another embodiment of the present invention; Figure 3 This is a flow chart of an overcurrent protection method according to another embodiment of the present invention; Figure 4 Flowchart of a method for determining an overcurrent protection threshold according to an embodiment of the present invention Figure 5 This is a schematic diagram of an overcurrent protection device according to an embodiment of the present invention; Figure 6 A schematic diagram of the structure of a computer system suitable for implementing a memory according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0017] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments. The details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention. The following embodiments and features therein may be combined with one another without conflict.

[0018] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention. The drawings only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be changed at will, and the component layout form may also be more complicated.

[0019] In the following description, numerous details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring the embodiments of the present invention.

[0020] Overcurrent protection systems commonly use a fixed current threshold as the trigger condition. This static protection mechanism is prone to malfunctioning under dynamic operating conditions, such as motor stalls and power device temperature rise, due to transient currents exceeding the threshold. For example, in automotive seat motor control systems, changes in wiring impedance and temperature drift in the on-resistance of the power MOS transistor can cause the actual current threshold to deviate from the designed value, resulting in functional failure or reduced system reliability. When a motor stall generates transient currents, the fixed threshold cannot distinguish between normal operating conditions and actual faults. Frequent protection triggering leads to increased equipment downtime and maintenance.

[0021] To address this issue, researchers discovered that a key flaw in traditional protection mechanisms lies in their failure to account for the impact of dynamic changes in environmental parameters on thresholds. Analyzing the operating data of the motor control system revealed that temperature changes and supply voltage fluctuations are the primary factors contributing to threshold drift. Based on this, the present invention proposes using a wiring impedance model as the basis for calculating the basic threshold, while also establishing a dynamic compensation mechanism for temperature and voltage. By dynamically correcting the basic threshold through real-time acquisition of environmental parameters, the overcurrent protection threshold can automatically adjust to changing operating conditions, eliminating the adaptability limitations of fixed thresholds in dynamic environments.

[0022] See also Figure 1 , Figure 1 This is a flow chart of an overcurrent protection method according to an embodiment of the present invention. Figure 1 In the overcurrent protection method, there are: Step S110, obtaining overcurrent protection influencing factors, which include temperature drift and voltage fluctuation; Step S120, dynamically compensating the basic overcurrent threshold according to the overcurrent protection influencing factors to obtain the overcurrent protection threshold; the basic overcurrent threshold is determined based on the harness impedance model; The harness impedance model refers to an equivalent circuit model established by measuring or calculating parameters such as cable resistance and contact resistance. I base express, , R ds Indicates the on-resistance of the power MOS tube, R harness represents the harness impedance, , L Indicates the length of the harness. S Indicates the cross-sectional area of ​​the harness; R contact Indicates contact impedance, which is the impedance generated by the punch point on the harness. , N Indicates the number of harness connections; V supply Indicates the power supply voltage, which can be 12V;k 1 and k 2 is a constant, which can be obtained by experimentally measuring the actual impedance under different wiring harness configurations and then fitting it.

[0023] Among them, dynamic compensation refers to an algorithm that corrects the basic overcurrent threshold according to the junction temperature and voltage parameters of the power MOS tube. It can be implemented by using a linear superposition compensation term to maintain the accuracy of the overcurrent protection threshold by eliminating the impact of environmental parameter changes on the threshold.

[0024] Step S130: When the real-time current value is greater than the overcurrent protection threshold, an overcurrent protection action is triggered to implement overcurrent protection for the protected object.

[0025] The real-time current value can be obtained by using a current sensor circuit with high-speed sampling capability, such as a Hall effect sensor or a shunt resistor in conjunction with an ADC converter (A / D converter or ADC, Analog to Digital Converter), to accurately capture transient changes in current.

[0026] For real-time current values, a sliding average filter can be applied to multiple sampling points within a set time window. After each ADC sampling, the new sample value is stored in a buffer and the average of the most recent multiple sampling points (up to 100 sampling points) is calculated as the filtered current value. This method effectively smooths short-term fluctuations and provides more stable current readings.

[0027] Specifically, a basic overcurrent threshold is established using a wiring harness impedance model. This basic overcurrent threshold takes into account inherent parameters such as wiring harness length, wiring harness cross-sectional area, and the number of wiring harness connections. During system operation, a temperature sensor continuously monitors the junction temperature of the MOS transistor, the power device, and a voltage sampling circuit tracks fluctuations in the supply voltage. When temperature changes and / or abnormal fluctuations in the supply voltage are detected, the basic overcurrent threshold is adjusted to obtain the overcurrent protection threshold. When the dynamically adjusted overcurrent protection threshold is exceeded by the real-time current, the driver circuit immediately executes an overcurrent protection action, such as disconnecting the power circuit, thereby achieving overcurrent protection for the protected object.

[0028] The present invention enables the protection threshold to have environmental adaptability through a dynamic compensation mechanism, which can not only avoid threshold failure caused by temperature drift, but also suppress false triggering caused by voltage fluctuation.

[0029] Generally speaking, the on-resistance of the power MOS tube R ds Changes significantly with temperature (e.g. at -25°C R ds =0.8mΩ, rising to 1.5mΩ at 60℃), resulting in the overcurrent protection threshold ( Ids = V ds / R ds ) fluctuates over the entire temperature range. For example, at low temperatures, the on-resistance R ds Reduce, if a fixed drain-source voltage is still used V ds , actual current threshold I ds Will be too high, may miss the overcurrent detection; at high temperature, the on-resistance R ds Increase, current threshold I ds Reduced, easy to trigger the protection by mistake. No dynamic compensation of on-resistance R ds Temperature drift leads to reduced system reliability. Based on this, an embodiment of the present invention proposes a temperature-compensated VDS threshold adjustment system. Figure 2 , Figure 2 FIG. 1 is a flow chart of an overcurrent protection method according to an embodiment of the present invention. Figure 2 In the overcurrent protection method, the overcurrent protection method also includes: Step S210, obtaining the real-time junction temperature of the power MOS tube; Real-time junction temperature refers to the operating junction temperature of the power MOS tube. This temperature can be acquired in real time using a temperature sensor or NTC thermistor, reflecting the impact of the current temperature on the on-resistance. For example, the NTC thermistor can be mounted at the center of the heat dissipation surface of the power MOS tube. A voltage divider circuit converts the NTC resistance into a voltage signal, which is then input into the MCU via an ADC. During PCB assembly, a high-precision temperature probe is used to calibrate the mapping between the NTC output and the actual MOS tube junction temperature. The temperature measured by the NTC thermistor can then be used to determine the power MOS tube's junction temperature.

[0030] Step S220, determining a first on-resistance corresponding to the real-time junction temperature based on the real-time junction temperature and a preset correlation relationship, wherein the correlation relationship represents a mapping relationship between the on-resistance and the junction temperature of the power MOS tube; The correlation relationship refers to a pre-established correspondence between on-resistance and junction temperature, which can be implemented using a discrete data table or a polynomial function model to convert the real-time junction temperature into a corresponding theoretical on-resistance value.

[0031] Step S230 , when the real-time junction temperature is not equal to the set temperature threshold, the first on-resistance is compensated and corrected to obtain a second on-resistance, so as to keep the overcurrent protection threshold constant when the temperature changes through the second on-resistance.

[0032] Specifically, the real-time junction temperature is measured using a temperature sensor to measure the operating temperature of the power MOS tube. The measured real-time junction temperature value is matched with the temperature-on-resistance mapping data in the associated relationship to obtain the first on-resistance corresponding to the current junction temperature. When the real-time junction temperature is detected to exceed the set temperature threshold, or when the real-time junction temperature is detected to be lower than the set temperature threshold, the first on-resistance is compensated based on the temperature deviation to generate a temperature-compensated second on-resistance. By substituting the corrected second on-resistance value into the overcurrent protection threshold calculation formula, the temperature compensation amount is included in the final threshold calculation, thereby eliminating the impact of temperature fluctuations on the stability of the overcurrent protection threshold.

[0033] Overcurrent protection threshold I _ set Said that due to I _ set Need to keep constant, according to , introduce compensation resistor , , by adjusting offset R ds temperature drift, ensuring Constant.

[0034] When the real junction temperature T When the temperature is lower than the set threshold, R ds If it is lower than the nominal value (such as 0.8mΩ at -25℃), it is necessary to increase (such as +0.2mΩ), so that the total equivalent resistance R ds + =1.0mΩ, maintain I _ set =33A (corresponding V ds =33A×1.0mΩ=33mV) to complete the low temperature compensation of the overcurrent protection threshold; When the real junction temperature T When the temperature is greater than the set threshold, R ds If the value is higher than the nominal value (such as 1.5mΩ at 60℃), it is necessary to reduce (such as -0.3mΩ), making the total equivalent resistance R ds + =1.2mΩ, maintain I _ set =33A (corresponding V ds =33A×1.2mΩ=39.6mV) to complete the high temperature compensation of the overcurrent protection threshold; The present invention dynamically corrects the on-resistance parameters so that the overcurrent protection threshold is always calculated based on the accurate parameters under the current actual working conditions, thereby solving the problem of threshold fluctuation caused by temperature changes, avoiding false triggering or failure of the protection function due to on-resistance drift, and improving the protection accuracy of the system over a wide temperature range.

[0035] In one embodiment, the association relationship includes: a discrete data table and / or a polynomial function model; wherein, When constructing a discrete data table, the discrete data table is optimized by an optimization method, the optimization method including at least one of the following: using linear interpolation to calculate the on-resistance corresponding to the real-time junction temperature between adjacent temperature points, merging intervals where the on-resistance change rate of adjacent temperature points is less than a set threshold, and configuring a higher temperature sampling point density in the nonlinear interval than in the linear interval; When constructing a polynomial function model, the root mean square error of the fitting results is calculated and the fitting quality is evaluated by the root mean square error.

[0036] The discrete data table refers to a mapping relationship between discrete temperature points and corresponding on-resistances. Specifically, the temperature-resistance correspondence table can be established by experimental measurement.

[0037] Linear interpolation is used to calculate the on-resistance between adjacent temperature points. For example, if the real-time junction temperature T = 17°C is between two sampling points of 10°C and 20°C, the resistance value of the real-time junction temperature can be calculated based on the linear relationship between the resistance values ​​of the two points. The linear relationship can be expressed as . R 10℃ Indicates that the junction temperature is 10 ℃ The on-resistance, R 20℃ Indicates that the junction temperature is 20 ℃ The on-resistance when .

[0038] Merging intervals where the on-resistance change rate is less than a set threshold means merging multiple temperature points into a single temperature interval when the resistance change rate between adjacent temperature points is less than the set threshold. For example, if the resistance change rate between the first and second temperature points in the first temperature interval is less than the set threshold, and the resistance change rate between the third and fourth temperature points in the second temperature interval is less than the set threshold, the first and second temperature intervals will be merged into a single linear segment, storing only the endpoint temperatures and resistance values.

[0039] Increasing the density of temperature sampling points means adding data collection points in the temperature range where the resistance change rate exceeds the set threshold. For example, in the high temperature range of 80-100°C, a data point is collected every 5°C, and in the low temperature range of 10-30°C, a data point is collected every 2°C.

[0040] The polynomial function model refers to the use of polynomial mathematical equations to fit the relationship between junction temperature and on-resistance, such as using a cubic polynomial function to describe the nonlinear change trend. For example, , a, b, c are fitting coefficients.

[0041] The root mean square error is used to quantify the degree of deviation between the polynomial fitting result and the measured data, such as by calculating the actual resistance value. and the fitting curve value The root mean square error of is used to evaluate the accuracy of the model. For example, .

[0042] Specifically, in the process of constructing a discrete data table, when the rate of change of on-resistance between adjacent temperature points is low, for example, the resistance changes slowly in the low temperature range, the amount of data storage can be reduced by merging temperature ranges. For temperature ranges where the resistance changes dramatically, such as high temperature areas, the model resolution is improved by increasing the density of temperature sampling points. The linear interpolation method ensures that continuous resistance values ​​can still be obtained for unsampled temperature points to avoid data jumps. When constructing a polynomial function model, the root mean square error between the fitting curve and the actual data is calculated. For example, when the error exceeds a predetermined threshold, the polynomial order is adjusted or the fitting parameters are reselected to optimize the model accuracy. Discrete models and function models can be used alone or in combination. For example, a discrete model is used in a temperature stable area, and a polynomial model is switched to in a nonlinear change area.

[0043] The present invention dynamically adjusts the sampling density and error feedback mechanism to ensure that the model accurately matches the temperature characteristics of the actual device while ensuring calculation efficiency.

[0044] Generally speaking, if the VDS overcurrent protection adopts a fixed current threshold, it cannot adapt to the on-resistance of the MOS tube. R ds Characteristics that change with temperature. For example: for low temperature environment (-40℃~0℃): on-resistance R ds Reduced. If the fixed threshold of 33A is maintained, the actual allowed current may exceed the device safety limit (such as 40A), resulting in leakage protection risk; for high temperature environment (70℃~125℃): on-resistance R ds Significantly increased, fixed threshold corresponding to V ds As the value increases, the protection may be falsely triggered, leading to functional failure (such as interruption of seat folding). Therefore, the VDS overcurrent protection with a fixed current threshold lacks temperature adaptability and cannot balance protection sensitivity and reliability within the full temperature range. Based on this, the present invention proposes a gradient overcurrent protection method. Figure 3 , Figure 3 FIG. 1 is a flow chart of an overcurrent protection method according to an embodiment of the present invention. Figure 3 In the overcurrent protection method, the overcurrent protection method also includes: Step S310, matching the real-time junction temperature of the power MOS tube with a preset temperature range set to obtain the preset temperature range to which the real-time junction temperature belongs; The temperature interval set refers to dividing the operating temperature range of the power MOS tube into multiple continuous or non-continuous sub-intervals, which can be divided into equal intervals or unequal intervals. For equal interval division, for example, -40℃ to 160℃ is divided into intervals of 10℃ each; for unequal interval division, it can be dynamically adjusted according to the temperature sensitivity characteristics of the MOS tube, for example, R ds Temperature ranges with high rates of change use denser intervals, while areas with more gradual changes use wider intervals, thus balancing computational efficiency and protection accuracy. For example, the operating temperature of a power MOS tube is divided into three ranges: -40°C to 0°C for low temperature, 0°C to 70°C for normal temperature, and 70°C to 125°C for high temperature. The overcurrent protection threshold corresponding to the normal temperature range of 0°C to 70°C can be 33A.

[0045] Step S320 , dynamically correcting the overcurrent protection threshold according to the preset temperature range to generate an optimized overcurrent protection threshold.

[0046] Specifically, when the real-time junction temperature enters a certain temperature range, the overcurrent protection threshold is adjusted based on the temperature range to which the real-time junction temperature belongs. For example, if the real-time junction temperature falls within the low temperature range, the overcurrent protection threshold is increased; if the real-time junction temperature falls within the high temperature range, the overcurrent protection threshold is decreased. For example, if the overcurrent protection threshold is 33A and the real-time junction temperature is -10°C, which falls within the low temperature range of -40°C to 0°C, the overcurrent protection threshold needs to be adjusted. By correcting the overcurrent protection threshold, the overcurrent protection threshold is increased, resulting in an overcurrent protection threshold of 35A. If the real-time junction temperature is 80°C, which falls within the high temperature range of 70°C to 125°C, the overcurrent protection threshold needs to be adjusted. By correcting the overcurrent protection threshold, the overcurrent protection threshold is decreased, resulting in an optimized overcurrent protection threshold of 30A.

[0047] The present invention converts temperature changes into discrete interval switching through temperature interval division and threshold adjustment, thereby solving the problem of overcurrent protection threshold fluctuation caused by power MOS tube junction temperature change and avoiding false triggering or protection failure.

[0048] In one embodiment, the overcurrent protection method further includes: A hysteresis threshold is set at the boundary of the temperature interval. When the temperature change crosses the boundary of the adjacent temperature interval, if the temperature change is greater than the hysteresis threshold, the overcurrent protection threshold is switched from the overcurrent protection threshold corresponding to the first temperature interval to the overcurrent protection threshold corresponding to the second temperature interval.

[0049] The hysteresis threshold refers to the preset temperature change critical value, which can be implemented by a fixed value or dynamic adjustment, such as setting it to 3°C or 5°C or ± the overcurrent protection threshold. 3%, which is used to suppress the triggering of threshold switching operations when the temperature fluctuates slightly near the temperature range boundary. The temperature range boundary refers to the dividing point between adjacent preset temperature ranges. For example, when the temperature is divided into two ranges of 0-60°C and 61-100°C, 60°C is the boundary, which is used to divide the overcurrent protection threshold corresponding to different temperature ranges.

[0050] Specifically, when the real-time temperature fluctuates near the boundary of adjacent temperature intervals, if the temperature change does not exceed the hysteresis threshold, the system maintains the overcurrent protection threshold corresponding to the current temperature interval unchanged. For example, when the temperature rises from 49°C to 61°C, if the hysteresis threshold is 3°C, the temperature must change by more than 3°C to trigger the threshold switch. At this time, the system adjusts the overcurrent protection threshold from the threshold corresponding to the 0-60°C interval to the threshold corresponding to the 61-100°C interval. Conversely, if the temperature fluctuates around 60°C but does not exceed the hysteresis threshold, for example, fluctuating between 48°C and 53°C, the system still maintains the original threshold, thereby avoiding frequent switching caused by small temperature changes.

[0051] The present invention introduces a hysteresis threshold and executes threshold switching only when the temperature change amplitude is large enough. It solves the problem of frequent switching of the overcurrent protection threshold caused by temperature fluctuations when the temperature change crosses the boundary of adjacent temperature ranges, and avoids the system from generating threshold oscillations due to small fluctuations near the critical temperature point, thereby ensuring the stable triggering of the overcurrent protection action and improving system reliability.

[0052] See also Figure 4 , Figure 4 This is a flow chart of a method for determining an overcurrent protection threshold according to an embodiment of the present invention. Figure 4 In the above method, dynamic compensation is implemented on the basic overcurrent threshold according to the influencing factors of overcurrent protection to obtain a dynamically adjusted overcurrent protection threshold, including: Step S410: Obtaining a temperature drift compensation term and a voltage fluctuation compensation term; wherein the temperature drift compensation term is determined based on the difference between the real-time junction temperature of the power MOS tube and the reference junction temperature and a temperature compensation coefficient, and the voltage fluctuation compensation term is determined based on the difference between the real-time supply voltage and the reference supply voltage and the voltage fluctuation compensation coefficient; The temperature drift compensation term is a correction factor used to offset the effect of temperature changes on on-resistance. This is achieved by multiplying the difference between the real-time junction temperature and the reference junction temperature by a temperature compensation coefficient. This compensation term quantifies the contribution of temperature changes to threshold drift. The temperature compensation coefficient can be determined through MOS tube temperature drift testing.

[0053] The voltage fluctuation compensation term is a correction factor used to eliminate the effects of power supply voltage fluctuations. This is achieved by multiplying the difference between the real-time power supply voltage and the reference power supply voltage by the voltage fluctuation compensation coefficient. This compensation term reflects the impact of voltage fluctuations on current detection accuracy. The voltage fluctuation compensation coefficient can be designed based on system tolerance.

[0054] The reference junction temperature refers to the reference temperature of the power MOS tube under standard test conditions. The reference junction temperature can be 25°C.

[0055] The reference supply voltage refers to the standard supply voltage value set during system design. The reference supply voltage can be 12V.

[0056] Step S420, obtaining a current compensation value based on the temperature drift compensation term and the voltage fluctuation compensation term; Step S430: Compensate the basic overcurrent threshold by using the current compensation value to obtain an overcurrent protection threshold.

[0057] Specifically, during the operation of the system, the junction temperature data of the power MOS tube is collected in real time through the temperature sensor, and the instantaneous value of the power supply voltage is obtained through the voltage sampling circuit. The difference between the real-time junction temperature and the preset reference junction temperature is calculated, and the temperature drift compensation term is generated in combination with the temperature compensation coefficient. This coefficient can be obtained through experimental calibration and is used to characterize the degree of influence of unit temperature change on the on-resistance. Synchronously, the difference between the real-time power supply voltage and the reference voltage is combined with the voltage compensation coefficient to generate a voltage fluctuation compensation term. This coefficient can be calculated through circuit parameters and is used to characterize the influence of unit voltage change on the current detection loop. The temperature drift compensation term and the voltage fluctuation compensation term are superimposed to form a current compensation value, and the compensation value is superimposed on the basic overcurrent threshold calculated based on the harness impedance model to finally generate a dynamically adjusted overcurrent protection threshold. Among them, the current compensation value can be used express, , α Indicates the temperature compensation coefficient, which can be determined by MOS tube temperature drift test. T Indicates real-time junction temperature; β It represents the voltage fluctuation compensation coefficient, which can be designed according to the system tolerance. Vbat represents the real-time power supply voltage.

[0058] For the current compensation value, the temperature-voltage compensation calculation can be performed every 50ms. Specifically, at least three temperature sensor data (including motor winding temperature, harness temperature, PCB temperature) and power supply voltage are obtained, and then the preset temperature compensation coefficient is used. α and voltage fluctuation compensation coefficient β Calculate the current compensation value. This compensation value is then used to update the overcurrent protection threshold to achieve dynamic adjustment.

[0059] The present invention solves the problem of inaccurate overcurrent protection threshold caused by dynamic changes in environmental parameters by establishing a dual compensation mechanism for temperature and voltage, avoiding the misjudgment of transient current of motor stall as short-circuit fault. At the same time, it suppresses the unexpected drop in protection threshold caused by temperature increase, ensuring that the overcurrent protection system maintains stable protection performance under different working conditions, and improving the reliability of equipment operation.

[0060] In one embodiment, the overcurrent protection influencing factors further include: load characteristics, which are determined based on at least one of the following: motor current, motor output shaft speed; Dynamic compensation is performed on the basic overcurrent threshold according to the overcurrent protection influencing factors to obtain a dynamically adjusted overcurrent protection threshold, including: obtaining a characteristic compensation item, wherein the characteristic compensation item is determined based on the load characteristic and the load characteristic compensation coefficient; obtaining a current compensation value based on the characteristic compensation item, the temperature drift compensation item and the voltage fluctuation compensation item; and compensating the basic overcurrent threshold by the current compensation value to obtain the overcurrent protection threshold.

[0061] Load characteristics refer to dynamic parameters that reflect the operating status of the protected object. These can be achieved by using Hall sensors or current transformers to collect motor current in real time, or by measuring the motor output shaft speed through an encoder, to characterize changes in load conditions. Load characteristics can be determined through experimental calibration or machine learning optimization. For example, by collecting data such as motor current and motor output shaft speed through multiple seat folding operations, machine learning algorithms (such as k-means clustering or decision trees) are used to analyze the collected data and identify typical load characteristic patterns. These identified load characteristic patterns are stored in the system's non-volatile memory as a reference for subsequent dynamic adjustments. During the seat folding process, motor current and motor output shaft speed are collected in real time. Using sliding window technology, the real-time data is matched with pre-stored load characteristic patterns to obtain the load characteristics.

[0062] The characteristic compensation term refers to the compensation amount generated based on the load characteristics and the load characteristic compensation coefficient. A linear weighted algorithm can be used to convert the real-time values ​​of the motor current and speed into corresponding compensation values ​​to correct the deviation of the basic overcurrent threshold when the load changes suddenly.

[0063] The load characteristic compensation coefficient refers to a weight parameter that reflects the degree of influence of different load characteristics on the overcurrent protection threshold.

[0064] Specifically, during real-time operation, the motor current and motor output shaft speed are continuously monitored and converted into load characteristics. When a current surge or speed drop is detected, a characteristic compensation term is generated based on the preset load characteristic compensation coefficient. The characteristic compensation term is superimposed with the temperature drift compensation term and the voltage fluctuation compensation term to form a comprehensive current compensation value, which is superimposed on the basic overcurrent threshold to generate a dynamically adjusted overcurrent protection threshold. The overcurrent protection threshold is used I _ set express, , represents the load characteristic compensation coefficient, load _ factor Indicates load characteristics.

[0065] The present invention introduces load characteristic parameters and constructs a multi-dimensional compensation mechanism, so that the overcurrent protection threshold can synchronously respond to changes in load status, thereby maintaining the accuracy of the protection logic under complex working conditions such as motor stall and mechanical stagnation.

[0066] See also Figure 5 , Figure 5 This is a schematic diagram of an overcurrent protection device according to an embodiment of the present invention. Figure 5 In the overcurrent protection device, the overcurrent protection device includes: The factor acquisition module 510 is used to obtain overcurrent protection influencing factors; the overcurrent protection influencing factors include temperature drift and voltage fluctuation; The current compensation module 520 is used to dynamically compensate the basic overcurrent threshold according to the overcurrent protection influencing factors to obtain the overcurrent protection threshold; the basic overcurrent threshold is determined based on the wiring harness impedance model; The overcurrent trigger module 530 is used to trigger the overcurrent protection action when the real-time current value is greater than the overcurrent protection threshold, so as to implement overcurrent protection for the protected object.

[0067] It should be noted that the overcurrent protection device provided in the above embodiment and the overcurrent protection method provided in the above embodiment are based on the same concept. The specific manner in which each module and unit performs operations has been described in detail in the method embodiment and will not be repeated here. In actual applications, the overcurrent protection device provided in the above embodiment can, as needed, allocate the above functions to different functional modules, that is, divide the internal structure of the device into different functional modules to complete all or part of the functions described above, and this is not limited here.

[0068] An embodiment of the present invention also provides an overcurrent protection device, comprising: one or more processors; and a memory for storing one or more programs, wherein when the one or more programs are executed by one or more processors, the memory implements the overcurrent protection method in the above embodiment.

[0069] An embodiment of the present invention further provides one or more machine-readable media having instructions stored thereon, which, when executed by one or more processors, enable the processors to execute the overcurrent protection method in the above embodiment.

[0070] Figure 6 FIG1 shows a schematic diagram of a computer system structure suitable for implementing a memory according to an embodiment of the present invention. It should be noted that Figure 6 The computer system of the memory shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0071] like Figure 6 As shown, computer system 600 includes a central processing unit (CPU) 601, which can perform various appropriate actions and processes, such as executing the methods described in the above embodiments, based on programs stored in read-only memory (ROM) 602 or programs loaded from storage into random access memory (RAM) 603. RAM also stores various programs and data required for system operation. CPU 601, ROM 602, and RAM 603 are interconnected via bus 604. An input / output (I / O) interface 605 is also connected to bus 604.

[0072] The following components are connected to the I / O interface 605: an input section 606 including a keyboard, mouse, and the like; an output section 607 including devices such as a cathode ray tube (CRT), a liquid crystal display (LCD), and speakers; a storage section 608 including a hard disk; and a communication section 609 including a network interface card such as a LAN (Local Area Network) card or a modem. The communication section 609 performs communication processing via a network such as the Internet. A drive 610 is also connected to the I / O interface 605 as needed. Removable media 611, such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, is installed in the drive 610 as needed, so that computer programs read from the removable media can be installed in the storage section 608 as needed.

[0073] In particular, according to an embodiment of the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present invention includes a computer program product comprising a computer program carried on a computer-readable medium, the computer program including a computer program for executing the overcurrent protection method described above. In such an embodiment, the computer program can be downloaded and installed from a network via a communication component and / or installed from removable media 611. When executed by the central processing unit (CPU) 601, the computer program performs the various functions defined in the system of the present invention.

[0074] It should be noted that the computer-readable medium described in the embodiments of the present invention may be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium may, for example, be an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or component, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM) 603, read-only memory (ROM) 602, erasable programmable read-only memory (EPROM), flash memory, optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying a computer-readable computer program. This propagated data signal may take various forms, including, but not limited to, an electromagnetic signal, an optical signal, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. A computer program embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, or any suitable combination thereof.

[0075] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of the systems, methods, and computer program products according to various embodiments of the present invention. Each box in the flowchart or block diagram may represent a module, program segment, or portion of code, and the module or portion of the program segment code may contain one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the boxes may also occur in an order different from that marked in the accompanying drawings. For example, two boxes shown in succession may actually be executed substantially in parallel, or they may sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, or the combination of boxes in the flowchart, may be implemented using a dedicated hardware-based system that performs the specified functions or operations, or may be implemented using a combination of dedicated hardware and computer instructions.

[0076] The units involved in the embodiments of the present invention may be implemented in software or hardware, and the units described may also be provided in a processor. In some cases, the names of these units do not limit the units themselves.

[0077] Another aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon. When executed by a computer processor, the computer program causes the computer to perform the aforementioned overcurrent protection method. The computer-readable storage medium may be included in the memory described in the above embodiments, or may exist independently and not be incorporated into the memory.

[0078] Another aspect of the present invention provides a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the overcurrent protection method provided in each of the above embodiments.

[0079] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. An overcurrent protection method, characterized in that: The overcurrent protection includes: Obtaining overcurrent protection influencing factors; the overcurrent protection influencing factors include temperature drift and voltage fluctuation; Dynamically compensating a basic overcurrent threshold according to the overcurrent protection influencing factors to obtain an overcurrent protection threshold; the basic overcurrent threshold is determined based on a harness impedance model; When the real-time current value is greater than the overcurrent protection threshold, the overcurrent protection action is triggered to implement overcurrent protection for the protected object.

2. The overcurrent protection method according to claim 1, characterized in that: The overcurrent protection method further includes: Get the real-time junction temperature of the power MOS tube; Determining a first on-resistance corresponding to the real-time junction temperature based on a correlation between the real-time junction temperature and a preset correlation, wherein the correlation represents a mapping relationship between the on-resistance and the junction temperature of the power MOS tube; When the real-time junction temperature is not equal to the set temperature threshold, the first on-resistance is compensated and corrected to obtain a second on-resistance, so that the overcurrent protection threshold is kept constant when the temperature changes through the second on-resistance.

3. The overcurrent protection method according to claim 2, characterized in that: The association relationship includes: a discrete data table and / or a polynomial function model; wherein, When constructing the discrete data table, the discrete data table is optimized by an optimization method, and the optimization method includes at least one of the following: Use linear interpolation to calculate the on-resistance corresponding to the real-time junction temperature between adjacent temperature points, merge the intervals where the on-resistance change rate of adjacent temperature points is less than the set threshold, and configure the temperature sampling point density in the nonlinear interval to be higher than that in the linear interval; When constructing the polynomial function model, the root mean square error of the fitting result is calculated, and the fitting quality is evaluated by the root mean square error.

4. The overcurrent protection method according to claim 2, wherein: The overcurrent protection method further includes: Matching the real-time junction temperature of the power MOS tube with a preset temperature range set to obtain the preset temperature range to which the real-time junction temperature belongs; The overcurrent protection threshold is dynamically modified according to the preset temperature range to generate an optimized overcurrent protection threshold.

5. The overcurrent protection method according to claim 4, characterized in that: The overcurrent protection method further includes: A hysteresis threshold is set at the boundary of the temperature interval. When the temperature change crosses the boundary of an adjacent temperature interval, if the temperature change is greater than the hysteresis threshold, the overcurrent protection threshold is switched from the overcurrent protection threshold corresponding to the first temperature interval to the overcurrent protection threshold corresponding to the second temperature interval.

6. The overcurrent protection method according to claim 1, characterized in that: The dynamically compensating the basic overcurrent threshold according to the overcurrent protection influencing factors to obtain the overcurrent protection threshold includes: Obtaining a temperature drift compensation term and a voltage fluctuation compensation term; wherein the temperature drift compensation term is determined based on a difference between a real-time junction temperature of the power MOS tube and a reference junction temperature and a temperature compensation coefficient, and the voltage fluctuation compensation term is determined based on a difference between a real-time supply voltage and a reference supply voltage and a voltage fluctuation compensation coefficient; Obtaining a current compensation value based on the temperature drift compensation term and the voltage fluctuation compensation term; The basic overcurrent threshold is compensated by the current compensation value to obtain an overcurrent protection threshold.

7. The overcurrent protection method according to claim 6, characterized in that: The overcurrent protection influencing factors further include: load characteristics, which are determined based on at least one of the following: Motor current, motor output shaft speed; The dynamically compensating the basic overcurrent threshold according to the overcurrent protection influencing factors to obtain the overcurrent protection threshold includes: Obtaining a characteristic compensation item, wherein the characteristic compensation item is determined based on a load characteristic and a load characteristic compensation coefficient; Obtaining a current compensation value based on the characteristic compensation item, the temperature drift compensation item, and the voltage fluctuation compensation item; The basic overcurrent threshold is compensated by the current compensation value to obtain an overcurrent protection threshold.

8. An overcurrent protection device, characterized in that: The overcurrent protection device comprises: A factor acquisition module is used to obtain overcurrent protection influencing factors; the overcurrent protection influencing factors include temperature drift and voltage fluctuation; a current adjustment module, configured to dynamically compensate a basic overcurrent threshold according to the overcurrent protection influencing factors to obtain a dynamically adjusted overcurrent protection threshold; the basic overcurrent threshold is determined based on a harness impedance model; The overcurrent trigger module is used to trigger the overcurrent protection action when the real-time current value is greater than the overcurrent protection threshold, so as to achieve overcurrent protection for the protected object.

9. An overcurrent protection device, characterized in that: include: one or more processors; and One or more machine-readable media having instructions stored thereon, when executed by the one or more processors, enable the device to perform the overcurrent protection method according to any one of claims 1 to 7.

10. A machine-readable medium, characterized in that Instructions are stored thereon, which, when executed by one or more processors, enable the processors to execute the overcurrent protection method according to any one of claims 1 to 7.

Images