Arc discharge protection method and vehicle

Abstract

The invention provides an arc discharge protection method and a vehicle. The arc discharge protection method comprises the following steps that during the operation period of a load, an arc characteristic signal generated by the load is obtained; calculating arc energy based on the arc characteristic signal if the arc characteristic signal indicates that the power distribution system generates an arc; determining a risk level of the load according to the arc energy, and matching a protection strategy corresponding to the power distribution system according to the risk level of the load; and performing arc discharge protection on the power distribution system based on the protection strategy. According to the invention, the absorption of arc energy is more targeted, and the reliability of arc absorption is improved.

Description

Technical Field

[0001] This application relates to the field of low-voltage power distribution system technology, specifically to an arc discharge protection method and a vehicle. Background Technology

[0002] Currently, automotive low-voltage power supply systems generally use 12V. When a circuit is plugged in or disconnected, a small electric arc may occur, but it usually extinguishes quickly on its own and does not damage the controller or connectors. With the increase in automotive electrical equipment and power demands, low-voltage power supply systems are evolving from the traditional 12V to 48V. The 48V system offers higher power density, but its higher voltage level also makes it more prone to arcing during circuit plugging or disconnection. Related arc discharge protection solutions rely on fuse protection, which has a slow response time and cannot provide targeted protection against arcing. Summary of the Invention

[0003] This application provides an arc discharge protection method and vehicle, which makes the absorption of arc energy more targeted and improves the reliability of arc absorption.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, embodiments of this application provide an arc discharge protection method, comprising: acquiring an arc characteristic signal generated by the load during load operation; calculating arc energy based on the arc characteristic signal when the arc characteristic signal indicates that an arc has been generated in the power distribution system; determining the risk level of the load based on the arc energy, and matching a corresponding protection strategy for the power distribution system based on the risk level of the load; and performing arc discharge protection on the power distribution system based on the protection strategy.

[0005] It is understood that the solution provided in this application embodiment is to determine whether an arc has occurred by collecting arc characteristic signals during load operation in real time, further assess the load risk level by combining arc energy, and match the corresponding protection strategy accordingly. This enables the matching of the corresponding protection strategy of the power distribution system for loads with different risk levels, making the absorption of arc energy more targeted and improving the reliability of arc absorption.

[0006] In some embodiments, acquiring the arc characteristic signal generated by the load includes: acquiring the load current signal and the contact voltage signal in the power distribution system; performing feature extraction on the contact voltage signal to obtain the peak voltage and voltage change rate of the arc; performing feature extraction on the load current signal to obtain the peak current and current change rate of the arc; and determining the arc characteristic signal based on at least one of the peak voltage, voltage change rate, peak current, and current change rate of the arc.

[0007] It is understood that the solution provided in this application embodiment is to obtain arc feature signals by collecting load current signals and contact voltage signals in the power distribution system and extracting features. This can improve the accuracy of the arc feature signals, which is beneficial to improving the accuracy of subsequent arc energy calculations, and further making the matching protection strategy corresponding to the power distribution system more accurate.

[0008] In some embodiments, the arc discharge protection method further includes: determining an arc characteristic signal indicating that an arc is generated in the power distribution system when the current change rate is greater than a preset current change rate threshold; or, determining an arc characteristic signal indicating that an arc is generated in the power distribution system when the voltage change rate is greater than a preset voltage change rate threshold and the amplitude of the load current signal is greater than a preset current threshold.

[0009] It is understood that the solution provided in this application, by extracting the rate of change of load current as an arc characteristic signal, can quickly identify arc phenomena in the early stages of arc occurrence, improve detection sensitivity and response speed, and provide a reliable basis for the activation of subsequent protection strategies. Alternatively, by using both voltage change rate and load current as arc characteristic signals, the characteristics of arc occurrence can be more comprehensively characterized, improving the accuracy and robustness of arc identification, especially maintaining good detection performance under complex working conditions.

[0010] In some embodiments, matching the protection strategy corresponding to the power distribution system according to the risk level of the load includes: when the risk level of the load is high, determining the protection strategy to include a protection strategy of centralized arc absorption circuit and a protection strategy of distributed arc absorption circuit; when the risk level of the load is medium, determining the protection strategy to include a protection strategy of centralized arc absorption circuit; and when the risk level of the load is low, determining the protection strategy to include a protection strategy of filter absorption circuit.

[0011] It is understood that the solution provided in this application embodiment achieves a graded protection mechanism by selecting different protection strategies according to the risk level of the load. This ensures the safety of high-risk loads without overprotecting low-risk loads, thereby further improving the reliability of arc absorption.

[0012] In some embodiments, the centralized arc absorption circuit includes a primary protection unit, a secondary protection unit, and a clamping unit, wherein the protection level of the secondary protection unit is higher than that of the primary protection unit; the primary protection unit is connected in parallel across the two ends of the input power supply or connector; the input side of the secondary protection unit is connected to the output side of the primary protection unit, and the output side of the secondary protection unit is connected to the input side of the clamping unit; the output side of the clamping unit is connected in parallel with the load; wherein, when the risk level of the load is high-risk or medium-risk, the protection strategy of the centralized arc absorption circuit includes: the primary protection unit clamping the surge voltage of the input power supply or connector; the secondary protection unit absorbing voltage spikes missed by the primary protection unit and suppressing high-frequency arc energy; and the clamping unit turning on the first transistor in the event of an arc to reduce the contact voltage of the circuit breaker in the power distribution system to a safe threshold.

[0013] It is understood that the solution provided in this application embodiment achieves multi-level protection through a layered centralized arc absorption circuit, effectively absorbs arc energy and limits contact voltage, prevents equipment damage or safety accidents caused by arc, and can improve the safety of the power distribution system.

[0014] In some embodiments, the distributed arc absorption circuit includes a pre-charging circuit, which includes a first switching transistor unit, a first driving circuit, a switching array, and a second driving circuit. A first terminal of the load is connected to a first power supply V1, a second terminal of the load is connected to a first terminal of the first switching transistor unit, the second terminal of the first switching transistor unit is grounded, a control terminal of the first switching transistor unit is connected to an output terminal of the first driving circuit, and an input terminal of the first driving circuit is used to receive a first control signal. The control terminal of the switching array is connected to an output terminal of the second driving circuit. The first terminal of the load is connected to the first power supply, and the second terminal of the load is connected to a second terminal of the first switching transistor unit. When the load's risk level is high, the strategy of the distributed arc absorption circuit includes: controlling both the first switching transistor unit and the switching array to be in a turned-off state when the power distribution system is powered on; determining the appropriate switching state based on the load's operating status and requirements. A pre-charge current threshold is set. When the collected pre-charge current is greater than or equal to the pre-charge current threshold, the duty cycle of the first control signal is reduced, and the first drive circuit is controlled to output the first control signal with reduced duty cycle to control the on or off duration of the first switching unit, so that the pre-charge current is less than the pre-charge current threshold. When the pre-charge current is less than the pre-charge current threshold, and the difference between the voltage of the first power supply and the collected pre-charge voltage meets the first preset condition, the duty cycle of the first control signal is increased to improve the charging speed of the pre-charge circuit. When the pre-charge current is less than the pre-charge current threshold, and the difference between the voltage of the first power supply and the pre-charge voltage meets the second preset condition, the first drive circuit controls the first switching unit to turn off, so that the pre-charging of the pre-charge circuit is completed. The second drive circuit controls the switch array to turn on, so that the load enters the normal working state.

[0015] It is understood that the solution provided in this application embodiment achieves dynamic pre-charge management of high-risk loads by adopting a pre-charge circuit with closed-loop feedback control, effectively limiting the surge current at the moment of power-on, reducing the possibility of arc generation, improving charging efficiency, and ensuring stable system operation.

[0016] In some embodiments, the filter absorption circuit includes a resistor-capacitor filter circuit; or, the filter absorption circuit includes a resistor-capacitor filter circuit and a transient voltage suppressor.

[0017] It is understood that the solution provided in this application embodiment can effectively absorb high-frequency noise and transient voltage caused by electric arc by using a resistor-capacitor filter circuit or a combination of a resistor-capacitor filter circuit and a transient voltage suppressor. It is suitable for simple protection needs of low-risk loads, has a compact structure, low cost, and is suitable for large-scale applications.

[0018] In some embodiments, calculating arc energy based on arc characteristic signals includes: acquiring the peak voltage and peak current of the arc in the arc characteristic signals; acquiring the duration of the arc; and performing an integral operation on the peak voltage and peak current of the arc within the duration to obtain the arc energy.

[0019] It is understood that the solution provided in this application embodiment can accurately obtain the arc energy by integrating the peak voltage and peak current of the arc over a continuous period of time, thereby improving the accuracy of arc energy calculation and further improving the accuracy of subsequent load risk level classification.

[0020] In some embodiments, determining the risk level of a load based on arc energy includes: determining the risk level of the load as low risk when the arc energy is within a first preset range; determining the risk level of the load as medium risk when the arc energy is within a second preset range; and determining the risk level of the load as high risk when the arc energy is within a third preset range; wherein the upper limit of the first preset range is less than the lower limit of the second preset range; and the upper limit of the second preset range is less than the lower limit of the third preset range.

[0021] It is understood that the solution provided in this application is to divide the arc energy into multiple intervals and correspond to different risk levels to achieve a quantitative assessment of the arc hazard level. The quantitative assessment of the arc hazard level reflects the risk level of the load. The higher the risk level of the load, the more difficult it is to absorb the arc energy. This division facilitates the accurate matching of subsequent protection strategies and improves the intelligence and adaptability of the power distribution system.

[0022] In some embodiments, the method further includes: obtaining configuration parameters of the load; determining the load type of the load based on the configuration parameters of the load; wherein the load type includes capacitive load and inductive load.

[0023] It is understood that the solution provided in this application embodiment: identifying load types in multiple ways, distinguishing load types helps to design targeted protection strategies and reduce the risk of arc discharge.

[0024] In some embodiments, the configuration parameters of the load include: the identifier of the load; or, the impedance characteristics of the circuit in which the load is located; or, the relationship between the current phase and the voltage phase of the load.

[0025] It is understood that the solution provided in this application embodiment can identify the load type of a load by different configuration parameters, thereby improving the flexibility of determining the load type.

[0026] In a second aspect, embodiments of this application provide a vehicle including a power distribution system and a control circuit, wherein the power distribution system is connected to the control circuit; wherein the power distribution system includes at least a circuit breaker and a protection circuit, and the protection circuit includes at least one of the following: a centralized arc absorption circuit, a distributed arc absorption circuit, and a filter absorption circuit; the control circuit is configured to implement the method as described in the first aspect. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the specification, serve to explain the technical solutions of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0028] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0029] Figure 1 A flowchart illustrating an arc discharge protection method provided in this application embodiment. Figure 1 ; Figure 2 A schematic diagram of a centralized arc absorption circuit provided in an embodiment of this application; Figure 3 This application provides a schematic diagram of the structure of a distributed arc absorption circuit according to an embodiment of the present application. Figure 4 A flowchart illustrating an arc discharge protection method provided in this application embodiment. Figure 2 ; Figure 5 A flowchart illustrating a method for determining the load type of a load according to an embodiment of this application; Figure 6 This is a schematic diagram of the structure of an arc discharge protection system provided in an embodiment of this application; Figure 7 A schematic diagram illustrating the relationship between the equivalent resistance of a MOSFET and the PWM duty cycle, provided in an embodiment of this application; Figure 8 A schematic diagram illustrating the relationship between pre-charge voltage and pre-charge current over time, provided for an embodiment of this application; Figure 9 This is a flowchart illustrating a strategy for a distributed arc absorption circuit provided in an embodiment of this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the specific technical solutions of this application will be further described in detail below with reference to the accompanying drawings of the embodiments of this application. The following embodiments are used to illustrate this application, but are not intended to limit the scope of this application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0032] In the following description, references to "some embodiments," "this embodiment," "this application embodiment," and examples, etc., describe a subset of all possible embodiments. However, it is understood that "some embodiments" may be the same subset or different subset of all possible embodiments and may be combined with each other without conflict.

[0033] The descriptions such as "first," "second," and "third" appearing in the embodiments of this application do not have a specific meaning (such as no order, nor do they indicate a special limitation on the number of devices in the embodiments of this application), but are merely for the purpose of clearly describing the embodiments of this application and do not constitute any limitation on the embodiments of this application.

[0034] To facilitate understanding of the technical solutions of the embodiments of this application, the relevant technologies or terms of the embodiments of this application are described below. The following relevant technologies or terms are optional solutions and can be combined with the technical solutions of the embodiments of this application in any way, and all of them fall within the protection scope of the embodiments of this application.

[0035] Currently, automotive low-voltage power distribution generally uses 12V power supply. When the circuit is closed / opened, a small electric arc may occur, but it usually extinguishes itself quickly and will not damage the controller or connector. Traditional 12V low-voltage systems rely on fuse protection, which has a slow response speed and cannot provide targeted protection against electric arcs.

[0036] With the increasing electrification of automobiles, the power of vehicle loads, and the proliferation of electrical devices, 48V low-voltage power supply systems are becoming the trend. While 48V systems offer higher power density than 12V systems, the lower DC arc sustaining voltage and the generally larger inductance / capacitance of loads make them more prone to sparking and arcing during insertion / removal or disconnection. Capacitive loads (such as large capacitors in controllers or DC-to-DC input current) generate huge inrush currents upon power-up; inductive loads (such as motors, pumps, and distributed inductance in wiring harnesses) generate backflow voltage when disconnected. Current solutions often rely on single resistor-capacitor filter circuits or passive absorption using transient voltage suppressors (TVS). However, both resistor-capacitor filter circuits and TVS solutions only provide local suppression, lacking global optimization and failing to simultaneously achieve the system objectives of spark-free insertion / removal, inductive voltage absorption, overvoltage clamping, and continuous controllability.

[0037] Furthermore, in related technologies, the pre-charging methods for large surge currents on loads are mostly fixed resistor pre-charging, relay-level pre-charging, or electronic switch pre-charging. However, while fixed resistor pre-charging is simple, it has a long pre-charging time and high energy consumption. Relay-level pre-charging improves efficiency to some extent, but it suffers from contact wear and insufficient lifespan. Electronic switch pre-charging, if using open-loop control, cannot balance speed and safety. Therefore, none of the above pre-charging solutions can meet the needs of future high-power electrical systems and the ability to adaptively adjust the pre-charging time according to load differences, and they are not effective at absorbing electric arcs.

[0038] In related technologies, control circuits identify circuit voltage / current to determine whether a parallel arc or a series arc is generated, and promptly disconnect the line load to avoid consequences such as fire caused by arc discharge.

[0039] Based on this, the inventors of this application discovered through research and analysis that the relevant arc discharge protection schemes rely on fuse protection, which has a slow response speed and cannot provide targeted protection against arcs.

[0040] Based on this, embodiments of this application provide the following arc discharge protection methods and vehicles, etc.

[0041] Figure 1 A flowchart illustrating an arc discharge protection method provided in this application embodiment. Figure 1 ,like Figure 1 As shown, the arc discharge protection method includes the following steps: S101. During load operation, acquire the arc characteristic signal generated by the load.

[0042] S102. When the arc characteristic signal indicates that the power distribution system has generated an arc, the arc energy is based on the arc characteristic signal.

[0043] S103. Determine the risk level of the load based on the arc energy, and match the corresponding protection strategy of the power distribution system according to the risk level of the load.

[0044] S104. Based on the protection strategy, arc discharge protection is implemented in the power distribution system.

[0045] Understandably, by collecting arc characteristic signals during load operation in real time, it is possible to determine whether an arc has occurred. Furthermore, by combining the arc energy to assess the load risk level, and matching the corresponding protection strategy accordingly, the power distribution system can be matched with protection strategies for loads of different risk levels, making the absorption of arc energy more targeted and improving the reliability of arc absorption.

[0046] The following describes further optional implementation methods and related terms for each of the above steps.

[0047] S101. During load operation, acquire the arc characteristic signal generated by the load.

[0048] In one example, obtaining the characteristic signal of the electric arc generated by the load can be achieved by: acquiring the load current signal Is and the contact voltage signal Vs in the power distribution system; and performing feature extraction on the contact voltage signal Vs to obtain the peak voltage U of the electric arc. arc And voltage change rate; feature extraction is performed on the load current signal Is to obtain the peak current I of the arc. arc and the rate of change of current; based on the peak voltage U of the electric arc. arc Voltage change rate, peak current I of the electric arc arc The characteristic signal of the electric arc is determined by at least one of the following: the rate of change of current.

[0049] In another example, the characteristic signals of the electric arc generated by the load can be obtained from: the spikes of the contact voltage signal Vs, the current mutation rate of the load current signal Is, and high-frequency oscillations, etc.

[0050] This application does not impose any particular limitation on the method for "acquiring the characteristic signal of the electric arc generated by the load".

[0051] It is understood that the solution provided in this application embodiment is to obtain arc feature signals by collecting load current signals and contact voltage signals in the power distribution system and extracting features. This can improve the accuracy of the arc feature signals, which is beneficial to improving the accuracy of subsequent arc energy calculations, and further making the matching protection strategy corresponding to the power distribution system more accurate.

[0052] S102. When the arc characteristic signal indicates that the power distribution system has generated an arc, calculate the arc energy based on the arc characteristic signal.

[0053] In one example, when the rate of change of current is greater than a preset rate of change of current threshold, an arc characteristic signal is determined to indicate that an arc has been generated in the power distribution system.

[0054] In another example, when the rate of change of voltage is greater than a preset voltage rate of change threshold and the value of the load current signal is greater than a preset current threshold, an arc characteristic signal is determined to indicate that an arc has been generated in the power distribution system.

[0055] For example, the preset voltage change rate threshold can be 50V / μs; the preset current threshold can be 10A. It is understood that "50V / μs" is an exemplary data point for the preset voltage change rate threshold and is not specific. In practical applications, the preset voltage change rate threshold can be changed according to actual needs, and this application does not impose any particular limitation on it. Similarly, "10A" is an exemplary data point for the preset current threshold and is not specific. In practical applications, the preset current threshold can be changed according to actual needs, and this application does not impose any particular limitation on it.

[0056] Understandably, extracting the rate of change of load current as an arc characteristic signal can quickly identify arc phenomena in their early stages, improving detection sensitivity and response speed, and providing a reliable basis for initiating subsequent protection strategies. Alternatively, by using both the rate of change of voltage and load current as arc characteristic signals, the characteristics of arc occurrence can be more comprehensively characterized, improving the accuracy and robustness of arc identification, especially maintaining good detection performance under complex operating conditions.

[0057] In some embodiments, the peak voltage U of the electric arc in the arc characteristic signal is obtained. arc and the peak current I of the electric arc arc ; Obtain the duration of the electric arc, tarc; Measure the peak voltage U of the electric arc within the duration tarc. arc and the peak current I of the electric arc arc By performing integration, the arc energy E is obtained. arc .

[0058] For example, the arc energy E arc It can be determined using the following formula (1): (1) Among them, U arc The peak voltage of the electric arc, i.e., the peak voltage of the contact voltage Vs, can be obtained by a voltage sensor; I arcThe peak current of the electric arc, i.e., the peak current of the load current signal Is, can be obtained by a current sensor; t1 represents the start time of the electric arc; t2 represents the end time of the electric arc; the difference between the end time t2 and the start time t1 is the duration tarc of the electric arc, which is the total duration from the start time of the electric arc to the end time of the electric arc. The duration of the electric arc can be obtained by a timer.

[0059] Understandably, by integrating the peak voltage and peak current of the arc over a sustained period, the arc energy can be accurately obtained, improving the accuracy of arc energy calculation and further enhancing the accuracy of subsequent load risk level classification.

[0060] S103. Determine the risk level of the load based on the arc energy, and match the corresponding protection strategy of the power distribution system according to the risk level of the load.

[0061] In one alternative embodiment, determining the risk level of the load based on the arc energy includes: at arc energy E arc When the load is within the first set range, its risk level is determined to be low risk; at arc energy E arc When the load is within the second set range, its risk level is determined to be medium risk; at the arc energy E arc When the load falls within the third defined range, its risk level is determined to be high risk.

[0062] Understandably, the magnitude of the electric arc energy is positively correlated with the severity of the damage to the load. In other words, the greater the arc energy, the greater the damage to the subsequent load, and the higher the risk level of the load.

[0063] The upper limit of the first set range is less than the lower limit of the second set range; the upper limit of the second set range is less than the lower limit of the third set range.

[0064] For example, the first set range can be: less than 5 megajoules (MJ), i.e., [0, 5MJ]; the second set range can be: greater than or equal to 5MJ and less than or equal to 20MJ, i.e., [5MJ, 20MJ]; the third set range can be: greater than 20MJ, i.e., (20MJ, +∞). That is to say, when the arc energy E... arc When the energy is less than 5 MJ, it is considered low risk; when 5 MJ ≤ arc energy E arc When the electric arc energy is ≤20MJ, it is determined to be low risk; when the electric arc energy E arc A value greater than 20 MJ is considered high-risk.

[0065] The risk level classification can be dynamically adjusted according to the load type, taking into account the characteristics of the 48V low-voltage power supply system, the load type, the tolerance limit of the contact material, and safety standards.

[0066] It should be noted that the higher the risk level of the load, the more difficult it is to absorb the arc energy, and the more likely it is to cause danger.

[0067] For example, in a vehicle's 48V low-voltage power distribution system, high-risk loads may include, but are not limited to, electric drives and batteries; medium-risk loads may include, but are not limited to, air conditioning compressors; and low-risk loads may include, but are not limited to, vehicle lights.

[0068] Understandably, by dividing arc energy into multiple intervals and corresponding to different risk levels, a quantitative assessment of the degree of arc hazard can be achieved. The quantitative assessment of the degree of arc hazard reflects the risk level of the load. The higher the risk level of the load, the more difficult it is to absorb arc energy. This division facilitates the precise matching of subsequent protection strategies and improves the intelligence and adaptability of the power distribution system.

[0069] In one optional embodiment, to implement a targeted arc discharge protection strategy and improve the reliability of arc absorption, the protection strategy corresponding to the power distribution system is matched according to the risk level of the load, including: When the load risk level is high, the protection strategy is determined to include both centralized arc absorption circuit protection strategy and distributed arc absorption circuit protection strategy.

[0070] When the load risk level is medium risk, the protection strategy should include a centralized arc absorption circuit.

[0071] When the load risk level is low, the protection strategy should include the protection strategy of the filter absorption circuit.

[0072] Understandably, by selecting different protection strategies based on the risk level of the load, a graded protection mechanism is achieved, which can ensure the safety of high-risk loads without overprotecting low-risk loads, thus further improving the reliability of arc absorption.

[0073] The following is combined with Figure 2 and Figure 3 The protection strategies for centralized arc absorption circuits and distributed arc absorption circuits are described in detail respectively.

[0074] Figure 2 A schematic diagram of a centralized arc absorption circuit provided in this application embodiment is shown below. Figure 2As shown, the centralized arc absorption circuit 20 includes: a primary protection unit 201, a secondary protection unit 202, and a clamping unit 203.

[0075] Among them, the protection level of the secondary protection unit 203 is higher than that of the primary protection unit 201.

[0076] Specifically, the primary protection unit 201 is connected in parallel across the input power supply VIN or the connector. This application does not impose any particular limitation on this; the following description uses the example of the primary protection unit 201 being connected in parallel across the input power supply VIN as an example. The input side of the secondary protection unit 202 is connected to the output side of the primary protection unit 201, and the output side of the secondary protection unit 202 is connected to the input side of the clamping unit 203; the output side of the clamping unit 203 is connected in parallel with the load 701.

[0077] For example, the primary protection unit 201 may include a varistor MOV; the secondary protection unit 202 may include a resistor-capacitor filter circuit and a first transient voltage suppressor TVS1; the clamping unit 203 may include a first transistor Q1, a bias resistor R3, a first Zener diode D1, a second Zener diode D2, and a low-pass filter circuit.

[0078] The resistor-capacitor filter circuit includes a first resistor R1, a first capacitor C1, a second capacitor C2, and a second resistor R2; the low-pass filter circuit includes a third capacitor C3 and a fourth resistor R4.

[0079] The first transient voltage suppressor, TVS1, is a transient voltage suppression diode to protect the circuit from voltage spike damage.

[0080] Specifically, the first terminal of the varistor MOV is connected to the input power supply VIN and the first terminal of the first resistor R1, respectively, and the second terminal of the varistor MOV is grounded; the second terminal of the first resistor R1 is connected to the first terminal of the first transient voltage suppressor TVS1, the anode plate of the first capacitor C1, the first terminal of the second resistor R2, and the first terminal of the first transistor Q1; the second terminal of the first transient voltage suppressor TVS1 is grounded, the cathode plate of the first capacitor C1 is connected to the anode plate of the second capacitor C2, and the cathode plate of the second capacitor C2 is grounded; the second terminal of the second resistor R2 is grounded; the first terminal of the first transistor Q1 is also connected to... The anode of the third capacitor C3 and the cathode of the second Zener diode D2 are connected; the second terminal of the first transistor Q1 is grounded; the control terminal of the first transistor Q1 is connected to the control circuit; the cathode of the third capacitor C3 is connected to the first terminal of the fourth resistor R4; the second terminal of the fourth resistor R4 is grounded; the anode of the second Zener diode D2 is grounded; the bias resistor R3 is connected in parallel between the control terminal and the second terminal of the first transistor Q1; the first Zener diode D1 is connected in parallel between the control terminal and the second terminal of the first transistor Q1, and its conduction direction points towards the control terminal of the first transistor Q1; the load 701 is connected in parallel across the second Zener diode D2.

[0081] In one embodiment, the second terminal of the varistor MOV, the second terminal of the first transient voltage suppressor TVS1, the cathode plate of the second capacitor C2, the second terminal of the second resistor R2, the second terminal of the first transistor Q1, and the second terminal of the fourth resistor R4 can be grounded together.

[0082] The first transistor Q1 can be a metal-oxide-semiconductor field-effect transistor (MOSFET), or simply a MOS transistor; it can also be a bipolar junction transistor (BJT), or simply a transistor. This application does not impose any particular limitation on this; the following explanation will use an N-channel MOSFET as an example. When the first transistor Q1 is an N-channel MOSFET, the source of the first transistor Q1 is its first terminal, the drain of the first transistor Q1 is its second terminal, and the gate of the first transistor Q1 is its control terminal.

[0083] For example, the input power supply VIN can be 48V.

[0084] It is understandable that a resistor-capacitor filter circuit includes a first resistor R1, a first capacitor C1, a second capacitor C2, and a second resistor R2. The first resistor R1, first capacitor C1, and second capacitor C2 can form a low-pass filter. When the frequency of the input power supply VIN voltage signal is low, the capacitive reactance of the first capacitor C1 and second capacitor C2 is large, the voltage drop across the first resistor R1 is small, and the output voltage across the series connection of the first capacitor C1 and second capacitor C2 is close to the voltage of the input power supply VIN. When the frequency increases, the capacitive reactance decreases, and the output voltage across the series connection of the first capacitor C1 and second capacitor C2 decreases, achieving signal attenuation and filtering. The first capacitor C1, second capacitor C2, and second resistor R2 can form a high-pass filter. By adjusting the values ​​of the first capacitor C1, second capacitor C2, and second resistor R2, the cutoff frequency can be controlled, achieving attenuation or amplification of high-frequency signals and thus filtering.

[0085] When the risk level of load 701 is high or medium risk, the protection strategy of the centralized arc absorption circuit 20 includes: a primary protection unit 201 for clamping the surge voltage of the input power supply VIN or connector; a secondary protection unit 202 for absorbing voltage spikes missed by the primary protection unit 201 and suppressing high-frequency arc energy; and a control circuit for turning on the clamping unit 203 so that the contact voltage Vs drops to a safe threshold.

[0086] The contact voltage Vs can be the voltage across the contacts of a contactor, circuit breaker, or relay on the connection between the power distribution system and the load. This application does not impose any particular limitation on this. The following description will use the voltage across the contacts of a circuit breaker as an example.

[0087] For example, the safety threshold can be less than or equal to 60V.

[0088] Understandably, by using a layered, centralized arc absorption circuit to achieve multi-level protection, effectively absorb arc energy and limit contact voltage, and prevent equipment damage or safety accidents caused by arcs, the safety of the power distribution system can be improved.

[0089] Figure 3 A schematic diagram of a distributed arc absorption circuit provided in this application embodiment is shown below. Figure 3 As shown, the distributed arc absorption circuit includes a pre-charging circuit. The pre-charging circuit includes a first switching transistor unit 306, a first driving circuit 305, a switching array 308, and a second driving circuit 307.

[0090] Specifically, the first end of the load 701 is connected to the first power supply V1, the second end of the load 701 is connected to the first end of the first switching transistor unit 306, the second end of the first switching transistor unit 306 is grounded to GND, the control terminal of the first switching transistor unit 306 is connected to the output terminal of the first driving circuit 305, and the input terminal of the first driving circuit 305 is used to receive the first control signal h1; the control terminal of the switch array 308 is connected to the output terminal of the second driving circuit 307; the first end of the load 701 is connected to the first power supply V1, and the second end of the load 701 is connected to the second end of the first switching transistor unit 306.

[0091] At this time, when the risk level of load 701 is high risk, the strategy of the distributed arc absorption circuit includes: when the power distribution system is powered on, controlling both the first switching unit 306 and the switching array 308 to be in the off state; determining the pre-charge current threshold according to the working state and demand of the load; when the collected pre-charge current is greater than or equal to the pre-charge current threshold, reducing the duty cycle of the first control signal h1, and controlling the first drive circuit 305 to output the first control signal with reduced duty cycle, so as to control the on or off duration of the first switching unit 306, so that the pre-charge current is less than the pre-charge current threshold. The first control signal h1 is increased to improve the charging speed of the pre-charging circuit when the pre-charging current is less than the pre-charging current threshold and the difference between the voltage of the first power supply and the pre-charging voltage meets the first preset condition. When the pre-charging current is less than the pre-charging current threshold and the difference between the voltage of the first power supply and the pre-charging voltage meets the second preset condition, the first switch unit 306 is turned off by the first drive circuit 305 to complete the pre-charging of the pre-charging circuit. The switch array 308 is turned on by the second drive circuit 307 to enable the load to enter the normal working state.

[0092] The load 701 can be either an inductive or capacitive load; this application does not impose any particular limitation on it. The following explanation will use an inductive load 701 as an example. When the load 701 is an inductive load, it can be a capacitor array (also called a pre-charged capacitor unit), including at least one capacitor. When the capacitor array includes two or more capacitors, the capacitors are arranged in parallel. The following explanation will use a capacitor array including three capacitors as an example.

[0093] In one embodiment, the supply voltage of the first power supply V1 can be taken from the voltage Vbatt of the battery system, which can be 12V.

[0094] In another alternative embodiment, the pre-charging circuit may further include: a voltage detection circuit 301, a pre-charging capacitor unit, a resistance sampling unit 303, and a current-limiting resistor unit 304.

[0095] Specifically, the first terminal of the voltage detection circuit 301 is connected to the first power supply V1 and the first terminal of the pre-charge capacitor unit (i.e., load 701); the second terminal of the pre-charge capacitor unit is connected to the first terminal of the resistance sampling unit 303; the second terminal of the resistance sampling unit 303 is connected to the first terminal of the current limiting resistor unit 304 and the first terminal of the first switching transistor unit 306; the current detection device 90 is also connected in parallel across the two ends of the resistance sampling unit 303; the second terminals of the first switching transistor unit 306 and the second terminals of the current limiting resistor unit 304 are grounded to GND; the control terminal of the first switching transistor unit 306 is connected to the output terminal of the first driving circuit 305, and the signal input terminal of the first driving circuit 305 is connected to the first control signal h1; the output terminal of the second driving circuit 307 is connected to the control terminal of the switch array 308, and the signal input terminal of the second driving circuit 307 is connected to the second control signal h2; the first terminal of the switch array 308 is connected to the first terminal of the resistance sampling unit 303; the first terminal of the load 701 is connected to the first terminal of the pre-charge capacitor unit, and the second terminal of the load 701 is grounded to GND.

[0096] The voltage detection circuit 301 is used to detect the voltage of the pre-charging circuit to obtain the pre-charging voltage; the current detection device 90 is used to collect the current of the pre-charging circuit to obtain the pre-charging current.

[0097] As an optional embodiment, to ensure the smooth conduction of the switch array 308, the distributed arc absorption circuit provided in this application embodiment may further include a signal self-test circuit 302. The signal self-test circuit 302 is disposed on the connection between the output terminal of the second driving circuit 307 and the control terminal of the switch array 308. The signal self-test circuit 302 is used to detect the signal output from the output terminal of the second driving circuit 307. When the signal output from the output terminal of the second driving circuit 307 meets the set conditions, the signal output from the output terminal of the second driving circuit 307 is output to the control terminal of the switch array 308.

[0098] For example, the voltage detection circuit 301 includes: a fifth diode D5, a sixth diode D6, a ninth capacitor C9, an eighteenth resistor R18, and a nineteenth resistor R19. Specifically, the cathode of the fifth diode D5 is connected to the fourth power supply V4, and the anode of the fifth diode D5 is connected to the cathode of the sixth diode D6 and the anode plate of the ninth capacitor C9, respectively; the anode plate of the ninth capacitor C9 can serve as the sampling port h4 of the voltage detection circuit 301; the first terminal of the eighteenth resistor R18 serves as the first terminal of the voltage sampling resistor 301 and is connected to the first power supply V1, and the second terminal of the eighteenth resistor R18 is connected to the first terminal of the nineteenth resistor R19; the anode of the sixth diode D6, the cathode plate of the ninth capacitor C9, and the second terminal of the nineteenth resistor R19 are grounded to GND.

[0099] For example, the pre-charge capacitor unit includes multiple capacitors connected in parallel, such as three: a sixth capacitor C6, a seventh capacitor C7, and an eighth capacitor C8. The anode plate of the seventh capacitor C7 can be optionally connected as the first terminal of the pre-charge capacitor unit (i.e., the first terminal of the load 701) to the first terminal of the eighteenth resistor R18, and the cathode plate of the seventh capacitor C7 can be optionally connected as the second terminal of the pre-charge capacitor unit (i.e., the second terminal of the load 701) to the first terminal of the resistance sampling unit 303; the sixth capacitor C6 is connected in parallel across the seventh capacitor C7; and the eighth capacitor C8 is connected in parallel across the seventh capacitor C7.

[0100] For example, the resistance sampling unit 303 includes at least one sampling resistor. When two or more sampling resistors are included, the multiple sampling resistors are connected in series. This application does not make any special limitation in this regard, and the following description takes a resistance sampling unit 303 including a single sampling resistor Rs as an example. Then, the first end of the sampling resistor Rs is connected as the first end of the resistance sampling unit 303 and the second end of the pre-charge capacitor unit, and the two ends of the sampling resistor Rs are connected as the second ends of the resistance sampling unit 303 and the first end of the current limiting resistor unit 304 and the first end of the first switching transistor unit 306, respectively.

[0101] Exemplarily, the current-limiting resistor unit 304 includes at least one current-limiting resistor. When two or more current-limiting resistors are included, the multiple current-limiting resistors are connected in parallel. This application does not particularly limit this; the following description uses an example where the current-limiting resistor unit 304 includes one current-limiting resistor R22. Then, the first end of the current-limiting resistor R22 is connected as the first end of the current-limiting resistor unit 304 and the two ends of the sampling resistor Rs, and the second end of the current-limiting resistor R22 is grounded to GND as the second end of the current-limiting resistor unit 304.

[0102] For example, the first driving circuit 305 includes: a second transistor Q2, a third transistor Q3, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, and a seventeenth resistor R17. Specifically, the control terminal of the second transistor Q2 serves as the signal input terminal of the first driving circuit 305 and is connected to the first control signal h1. The first terminal of the second transistor Q2 is connected to the control terminal of the second power supply V2 and the third transistor Q3, respectively. The second terminals of the second transistor Q2 and the third transistor Q3 are grounded to GND. The first terminal of the third transistor Q3 serves as the output terminal of the first driving circuit 305 and is connected to the control terminal of the second power supply V2 and the first switching transistor unit 306, respectively. A sixteenth resistor R16 is connected in series on the connection line between the control terminal of the second transistor Q2 and the first control signal h1. A fourteenth resistor R14 is connected in series on the connection line between the first terminal of the second transistor Q2 and the second power supply V2. The first terminal of the seventeenth resistor R17 is connected to the control terminal of the second transistor Q2, and the second terminal of the seventeenth resistor R17 is connected to the second terminal of the second transistor Q2. A fifteenth resistor R15 is connected in series on the connection line between the first terminal of the third transistor Q3 and the second power supply V2.

[0103] Among them, the sixteenth resistor R16 serves as a current limiter; the seventeenth resistor R17 serves as a bias resistor; and the fourteenth resistor R14 and the fifteenth resistor R15 serve as pull-up resistors.

[0104] In this application, the second transistor Q2 and the third transistor Q3 can be either MOSFETs or BJTs, without any particular limitation. The following explanation will use the example of both second transistor Q2 and third transistor Q3 being NPN transistors. It is understood that when second transistor Q2 is an NPN transistor, its base is the control terminal, i.e., the signal input terminal of the first driving circuit 305; its collector is its first terminal; and its emitter is its second terminal. Similarly, when third transistor Q3 is an NPN transistor, its base is the control terminal; its collector is its first terminal, i.e., the output terminal of the first driving circuit 305; and its emitter is its second terminal.

[0105] For example, the first switching transistor unit 306 includes: a first switching transistor MOS1, a twentieth resistor R20, a twenty-first resistor R21, and a tenth capacitor C10. Specifically, the control terminal of the first switching transistor MOS1 is connected to the collector of the third transistor Q3 as the control terminal of the first switching transistor unit 306; the first terminal of the first switching transistor MOS1 is connected to the second terminal of the sampling resistor Rs as the first terminal of the first switching transistor unit 306; the second terminal of the first switching transistor MOS1 is grounded to GND as the second terminal of the first switching transistor unit 306; the twentieth resistor R20 is connected in series on the connection line between the control terminal of the first switching transistor MOS1 and the collector of the third transistor Q3; the anode plate of the tenth capacitor C10 is connected to the control terminal of the first switching transistor MOS1, and the cathode plate of the tenth capacitor C10 is connected to the second terminal of the first switching transistor MOS1; the first terminal of the twenty-first resistor R21 is connected to the control terminal of the first switching transistor MOS1, and the second terminal of the twenty-first resistor R21 is connected to the second terminal of the first switching transistor MOS1.

[0106] In this application, the first switching transistor MOS1 can be either a MOSFET or a BJT, without any particular limitation. The following explanation will use an N-type MOSFET as an example. It is understood that when the first switching transistor MOS1 is an N-type MOSFET, its gate is the control terminal of the first switching transistor MOS1, which is also the control terminal of the first switching transistor unit 306. The drain of the first switching transistor MOS1 is its first terminal, which is also the first terminal of the first switching transistor unit 306. The source of the first switching transistor MOS1 is its second terminal, which is also the second terminal of the first switching transistor unit 306.

[0107] It should be noted that the first switching transistor MOS1 is an N-type MOS transistor with a body diode (also known as a parasitic diode or freewheeling diode).

[0108] Among them, the twentieth resistor R20 serves to limit current; the twenty-first resistor R21 serves to bias; and the tenth capacitor C10 serves to suppress sudden changes in the gate voltage of the first switch MOS1.

[0109] For example, the second driving circuit 307 includes: a fourth transistor Q4, a fifth transistor Q5, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, and a thirteenth resistor R13. Specifically, the control terminal of the fourth transistor Q4 serves as the signal input terminal of the second driving circuit 307 and is connected to the second control signal h2. The first terminal of the fourth transistor Q4 is connected to the control terminals of the third power supply V3 and the fifth transistor Q5, respectively. The second terminals of the fourth transistor Q4 and the fifth transistor Q5 are grounded to GND. The first terminal of the fifth transistor Q5 serves as the output terminal of the second driving circuit 307 and is connected to the control terminals of the third power supply V3 and the switch array 308, respectively. A twelfth resistor R12 is connected in series on the connection line between the control terminal of the fourth transistor Q4 and the second control signal h2. A tenth resistor R10 is connected in series on the connection line between the first terminal of the fourth transistor Q4 and the third power supply V3. The first terminal of the thirteenth resistor is connected to the control terminal of the fourth transistor Q4, and the second terminal of the thirteenth resistor R13 is connected to the second terminal of the fourth transistor Q4. An eleventh resistor R11 is connected in series on the connection line between the first terminal of the fifth transistor Q5 and the third power supply V3.

[0110] Among them, the twelfth resistor R12 serves as a current limiter; the thirteenth resistor R13 serves as a bias resistor; and the tenth resistor R10 and the eleventh resistor R11 serve as pull-up resistors.

[0111] In this application, the fourth transistor Q4 and the fifth transistor Q5 can be either MOSFETs or BJTs; no particular limitation is made. The following explanation will use the example of both fourth transistor Q4 and fifth transistor Q5 being NPN transistors. It is understood that when fourth transistor Q4 is an NPN transistor, its base is the control terminal, i.e., the signal input terminal of the second driving circuit 307; its collector is its first terminal; and its emitter is its second terminal. Similarly, when fifth transistor Q5 is an NPN transistor, its base is the control terminal; its collector is its first terminal, i.e., the output terminal of the second driving circuit 307; and its emitter is its second terminal.

[0112] For example, the switch array 308 includes at least one switching transistor. This application does not impose any particular limitation on this; the following description uses an example of a switch array including three switching transistors, namely the second switching transistor MOS2, the third switching transistor MOS3, and the fourth switching transistor MOS4. Further, the switch array 308 may also include current-limiting resistors R5, R6, and R7. Specifically, the control terminals of the second switch MOS2, the third switch MOS3, and the fourth switch MOS4 are connected together as the control terminals of the switch array 308 and connected to the collector of the fifth transistor Q5; the first terminals of the second switch MOS2, the third switch MOS3, and the fourth switch MOS4 are connected together as the first terminal of the switch array 308 and connected to the first terminal of the sampling resistor Rs; the second terminals of the second switch MOS2, the third switch MOS3, and the fourth switch MOS4 are connected together as the second terminal of the switch array 308 grounded to GND; the current-limiting resistor R5 is connected in series on the connection line between the control terminal of the second switch MOS2 and the collector of the fifth transistor Q5; the current-limiting resistor R6 is connected in series on the connection line between the control terminal of the third switch MOS3 and the collector of the fifth transistor Q5; and the current-limiting resistor R7 is connected in series on the connection line between the control terminal of the fourth switch MOS4 and the collector of the fifth transistor Q5.

[0113] In this application, the second switch MOS2, the third switch MOS3, and the fourth switch MOS4 can be either MOSFETs or BJTs; no particular limitation is made. The following explanation will use an example where all three are N-channel MOSFETs (hereinafter referred to as "N-type MOSFETs"). It is understood that when the second switch MOS2 is an N-type MOSFET, its gate is the control terminal, its drain is its first terminal, and its source is its second terminal. Similarly, when the third switch MOS3 is an N-type MOSFET, its gate is the control terminal, its drain is its first terminal, and its source is its second terminal. When the fourth switch MOS4 is an N-type MOS transistor, the gate of the fourth switch MOS4 is the control terminal of the fourth switch MOS4, the drain of the fourth switch MOS4 is the first terminal of the fourth switch MOS4, and the source of the fourth switch MOS4 is the second terminal of the fourth switch MOS4.

[0114] It should be noted that the second switch MOS2, the third switch MOS3, and the fourth switch MOS4 are all N-type MOS transistors with body diodes.

[0115] For example, the signal self-test circuit 302 includes: a third diode D3, a fourth diode D4, a fifth capacitor C5, a fourth capacitor C4, an eighth resistor R8, and a ninth resistor R9. Specifically, the cathode of the third diode D3 is connected to the third power supply V3, and the anode of the third diode D3 is connected to the cathode of the fourth diode D4 and the anode plate of the fifth capacitor C5, respectively; the first end of the eighth resistor R8 serves as the second end of the signal self-test circuit 302 and is connected to the control terminal of the switch array 308, and the second end of the eighth resistor R8 is connected to the first end of the ninth resistor R9; the first end of the ninth resistor R9 is also connected to the anode plate of the fifth capacitor C5; the anode plate of the fifth capacitor C5 is also connected to the third control signal h3; the anode of the fourth diode D4, the cathode plate of the fifth capacitor C5, the cathode plate of the fourth capacitor C4, and the second end of the ninth resistor R9 are connected together as the third end of the signal self-test circuit 302, grounded (GND); the anode plate of the fourth capacitor C4 serves as the first end of the signal self-test circuit 302 and is connected to the collector of the fifth transistor Q5 and the first end of the eighth resistor R8, respectively.

[0116] At this point, when the risk level of load 701 is high risk, the strategy for the distributed arc absorption circuit includes: S1021. When the power distribution system is powered on, the first drive circuit 301 is turned off to turn off the first switching transistor unit 306; and the second drive circuit 302 is turned off to turn off the switch array 308.

[0117] It is understandable that, since the first switching transistor MOS1 in the first switching transistor unit 306 connected to the output terminal of the first driving circuit 301 is an N-type MOS transistor, which has the characteristic of "high level to turn on, low level to turn off", when the first driving circuit 301 is turned off, its output terminal is equivalent to providing a low level to the gate of the first switching transistor MOS1, causing the first switching transistor MOS1 to be in the off state, thereby realizing the turn-off of the first switching transistor unit 306.

[0118] It is understandable that since the second switch transistor MOS2, the third switch transistor MOS3, and the fourth switch transistor MOS4 in the switch array 308 connected to the output terminal of the second drive circuit 307 are all N-type MOS transistors, which have the characteristic of "high level to turn on, low level to turn off", when the output terminal of the second drive circuit 307 is turned off, its output terminal is equivalent to providing a low level to the gate of the second switch transistor MOS2, the gate of the third switch transistor MOS3, and the gate of the fourth switch transistor MOS4, causing the second switch transistor MOS2, the third switch transistor MOS3, and the fourth switch transistor MOS4 to be in the off state, thereby realizing the turn-off of the switch array 308.

[0119] At this time, the current flows through the following path: starting from the first power supply V1, passing through the pre-charge capacitor unit (i.e., load 701), the resistor sampling unit 303, and the current limiting resistor unit 304 before being grounded.

[0120] Because the current-limiting resistor unit 304 has a relatively large resistance, the initial surge current is limited to a very safe low level. At this time, the current detection device 90 will detect an initial current, which is the pre-charge current. This current will gradually decrease as the pre-charge capacitor unit charges.

[0121] S1022. Determine the pre-charge current threshold based on the operating status and requirements of load 701.

[0122] For example, the pre-charge current threshold can be adaptively adjusted according to the operating state and demand of the load 701. For instance, if the load 701 is operating at reduced power, then the pre-charge current demand for the load 701 is reduced. In this case, the pre-charge current threshold can be set to the upper limit I of the pre-charge current threshold. th1 If the load 701 operates in a boost power mode, then the pre-charge current requirement of the load 701 increases. In this case, the pre-charge current threshold can be set to the lower limit I of the pre-charge current threshold. th2 This application does not impose any specific limitations on this, and the pre-charge current threshold will be used as the upper limit I for the subsequent pre-charge current threshold. th1 The following example will be used to illustrate the point.

[0123] S1023, the pre-charge current at both ends of the acquisition resistor sampling unit 303 and the pre-charge voltage at the sampling port h4 of the voltage detection circuit 301.

[0124] It is understandable that since the two ends of the resistor sampling unit 303 are connected to the current detection device 90, the pre-charge current can be obtained through the current detection device 90.

[0125] It is understandable that since the function of the voltage detection circuit 301 is to detect voltage, the pre-charge voltage can be obtained by acquiring the voltage at the sampling port h4 of the voltage detection circuit 301.

[0126] S1024. Determine whether the pre-charge current is less than the pre-charge current threshold. If not, proceed to S1025; if yes, proceed to S1026.

[0127] Understandably, this is because the upper limit of the pre-charge current threshold is "the pre-charge current threshold I". th1 Using "as an example" as an example, therefore, it is necessary to determine the upper limit I of the pre-charge current and the pre-charge current threshold. th1 The relationship between the magnitudes, that is, whether the pre-charge current is less than the upper limit I of the pre-charge current threshold. th1 If not, then execute S1025; if yes, then execute S1026.

[0128] S1025. When the pre-charge current is greater than or equal to the pre-charge current threshold, reduce the duty cycle of the first control signal h1 and control the first drive circuit 305 to output the first control signal h1 with reduced duty cycle, so as to control the duration of the first switching transistor unit 306 being turned on or off, so that the pre-charge current is less than the pre-charge current threshold.

[0129] The first control signal h1 is issued by the control circuit. While the pre-charge current gradually decreases as the pre-charge capacitor cell charges, it remains greater than or equal to the pre-charge current threshold, meaning the pre-charge current is greater than or equal to the upper limit I of the pre-charge current threshold. th1 In this case, the duty cycle of the first control signal h1 can be reduced so that the first switching transistor unit 306 is turned on or off for a shorter period of time, thereby reducing the pre-charge current to below the upper limit I of the pre-charge current threshold. th1 .

[0130] The first control signal h1 is a pulse width modulation (PWM) signal.

[0131] At this point, the total resistance of the pre-charging circuit is R. 总 =R22 / / R eq（MOS1） Where, " / / " indicates parallel connection; "R" indicates parallel connection. eq（MOS1） "" indicates the equivalent resistance of the first switching transistor MOS1.

[0132] Depending on the duty cycle of the PWM signal, the conduction level of the MOSFET will vary, and its equivalent resistance will also differ. (See reference...) Figure 7 .

[0133] Figure 7This diagram illustrates the relationship between the equivalent resistance of a MOSFET and the PWM duty cycle, as provided in an embodiment of this application. It can be derived by fitting the conduction characteristics of the MOSFET and combining it with a model derived from the datasheet. For example, based on the typical on-resistance Rds(on) provided in the MOSFET datasheet, and combined with the modulation of the PWM signal, the equivalent resistance R of the MOSFET is... eq Relationship: R eq =Rds(on) / D.

[0134] Where D represents the duty cycle of the MOSFET, the equivalent resistance of the MOSFET as a function of the PWM duty cycle can be plotted using the theoretical relationship above. Figure 7 As shown. It should be noted that when the PWM signal duty cycle is 100%, it means the controlled MOSFET is fully on; when the PWM signal duty cycle is 0%, it means the controlled MOSFET is fully off. From Figure 7 As can be seen, when the duty cycle is small, the equivalent resistance is large. As the duty cycle of the PWM signal gradually approaches 100%, the MOSFET also gradually approaches the fully conducting state, and the equivalent resistance of the MOSFET also decreases.

[0135] By detecting the pre-charge current, a closed-loop control system is formed to dynamically adjust the duty cycle of the first control signal h1.

[0136] S1026. Determine the relationship between the difference between the voltage of the first power supply and the pre-charge voltage and the first preset condition and the second preset condition, and match the corresponding control strategy.

[0137] Understandably, as time increases, the precharge current will gradually decrease, while the precharge voltage will gradually increase, such as... Figure 8 As shown.

[0138] Specifically, when the pre-charge current is less than the pre-charge current threshold, as mentioned above, the upper limit I of the pre-charge current being less than the pre-charge current threshold is... th1 At this time, if the difference between the voltage of the first power supply and the pre-charge voltage meets the first preset condition, the duty cycle of the first control signal h1 is increased to improve the charging speed of the pre-charge circuit. At this time, the pre-charge current is still gradually decreasing.

[0139] The first preset condition refers to the difference between the voltage of the first power supply and the pre-charge voltage being within the range of [voltage of the first power supply * 5%, voltage of the first power supply * 20%].

[0140] At this time, if the difference between the voltage of the first power supply and the pre-charge voltage meets the second preset condition, the first drive circuit 305 is controlled to turn off, so as to turn off the first switching tube unit 306, so as to complete the pre-charge of the pre-charge circuit; and the second drive circuit 307 is controlled to turn on, so as to turn on the switch array 308, so as to put the load 701 into normal working state.

[0141] The second preset condition refers to the case where the difference between the voltage of the first power supply and the pre-charge voltage is less than 5% of the voltage of the first power supply.

[0142] Specifically, the control circuit 307 is turned on, meaning the control circuit can control the second control signal h2 to output a high-level signal. This high-level signal turns on the second drive circuit 307, resulting in a high-level output of the second control signal h2. Since the second switch MOS2, third switch MOS3, and fourth switch MOS4 in the switch array 308 are all N-type MOS transistors, exhibiting the characteristic of "high-level on, low-level off," the high-level second control signal h2 ensures that all three switches are in the on state, thus turning on the switch array 308. At this time, the load current can pass through the low-impedance switch array 308, allowing the load 701 to enter normal operating condition.

[0143] As another optional embodiment, when the pre-charge current drops to the lower limit Ith2 of the pre-charge current threshold, the duty cycle of the first control signal h1 may not be adjusted, and the current duty cycle may be maintained. Alternatively, if the difference between the voltage of the first power supply and the pre-charge voltage is greater than 5% of the voltage of the first power supply, when the pre-charge current is less than the pre-charge current threshold, the duty cycle of the first control signal h1 may also not be adjusted, and the current duty cycle may be maintained.

[0144] Understandably, by adopting a pre-charging circuit with closed-loop feedback control, dynamic pre-charging management of high-risk loads can be achieved, effectively limiting the surge current at the moment of power-on, reducing the possibility of arc generation, improving charging efficiency, and ensuring stable system operation.

[0145] The following describes the protection strategy for the filter absorption circuit when the load risk level is low.

[0146] In one embodiment, the protection strategy for the filter absorption circuit may include a resistor-capacitor filter circuit.

[0147] The resistor-capacitor filter circuit can be the resistor-capacitor filter circuit described above, or it can include a resistor and a capacitor connected in series, with the other end of the resistor connected to the power supply and the other end of the capacitor grounded. The load is connected in parallel across the capacitor. This application does not impose any particular limitations on this.

[0148] In another embodiment, the filter absorption circuit may include a resistor-capacitor filter circuit and a transient voltage suppressor. When the filter absorption circuit includes a resistor-capacitor filter circuit and a transient voltage suppressor, it can be the secondary protection unit 202 as described above, which will not be repeated here.

[0149] Understandably, by employing a resistor-capacitor filter circuit or a combination of a resistor-capacitor filter circuit and a transient voltage suppressor, high-frequency noise and transient voltage caused by electric arc can be effectively absorbed. This is suitable for simple protection needs of low-risk loads, and the structure is compact, inexpensive, and suitable for large-scale applications.

[0150] As another alternative embodiment, in some embodiments, such as Figure 4 As shown, the arc discharge protection method provided in this application embodiment further includes steps S105 and S106.

[0151] S105. Obtain the load configuration parameters.

[0152] In one example, this could be the first configuration parameter for obtaining the load.

[0153] The first configuration parameter may include the identifier of the load.

[0154] In yet another example, it could be a second configuration parameter for obtaining the load.

[0155] The second configuration parameter may include the impedance characteristics of the circuit where the load is located or the relationship between the current phase and voltage phase of the load.

[0156] Understandably, different configuration parameters can be used to identify the load type, thus improving the flexibility of determining the load type.

[0157] S106. Determine the load type based on the load configuration parameters.

[0158] The load types include capacitive loads and inductive loads.

[0159] For example, capacitive loads may include, but are not limited to, capacitors; inductive loads may include, but are not limited to, inductors.

[0160] Determining the load type can help in matching discharge protection strategies, allowing for the best possible matching of distributed arc absorption circuit strategies for capacitive loads.

[0161] In one example, determining the load type based on the load's configuration parameters can be achieved by statically identifying the load based on its first configuration parameters.

[0162] In another example, determining the load type based on the load's configuration parameters can be achieved by dynamically identifying the load type based on a second configuration parameter.

[0163] This application does not impose any specific limitations on this matter; the following is in conjunction with... Figure 5 Step S106 will be described in detail.

[0164] like Figure 5 As shown, in one embodiment, as in step S106A.

[0165] S106A. Determine the load type based on the load identifier.

[0166] For example, a table mapping identifiers to load types can be pre-set. Different identifiers represent different loads, and each load corresponds to a load type. By collecting the identifier of the load, the identifier is searched in the pre-set table mapping identifiers to load types. Once the identifier is found, the load type of the load corresponding to the identifier can be obtained, and it can be determined whether the load is a capacitive load or an inductive load.

[0167] In another embodiment, as in step S106B.

[0168] S106B. Determine the load type based on the impedance characteristics of the circuit in which the load is located.

[0169] For example, if the impedance changes significantly with frequency, it is an inductive load; if the impedance is close to zero at low frequencies, it is a capacitive load.

[0170] In yet another embodiment, such as step S106C.

[0171] S106C. Determine the load type based on the relationship between the current phase and voltage phase of the load.

[0172] For example, a small current excitation can be applied and the phase difference between the current and voltage can be observed. If the current phase follows the voltage phase, the load is an inductive load; if the current phase leads the voltage phase, the load is a capacitive load.

[0173] It is understood that the solution provided in this application embodiment: identifying load types in multiple ways, distinguishing load types helps to design targeted protection strategies and reduce the risk of arc discharge.

[0174] It is understood that the arc discharge protection method provided in this application optimizes the arc energy absorption and interruption process through multi-level suppression, active control, and dynamic variable impedance, thus ensuring the safety and stability of the power distribution system. Compared with related technologies, the arc discharge protection method provided in this application can absorb the arc in a timely manner when it is detected, clamp the voltage, and shut off the power supply promptly, achieving both arc absorption and protection with higher reliability.

[0175] In another embodiment of this application, a vehicle is provided, including a power distribution system and a control circuit, wherein the power distribution system is connected to the control circuit; wherein the power distribution system includes at least a circuit breaker and a protection circuit, and the protection circuit includes at least one of the following: a centralized arc absorption circuit, a distributed arc absorption circuit, and a filter absorption circuit; the control circuit is configured to implement any of the arc discharge protection methods as described in the foregoing embodiments.

[0176] For detailed information on the "centralized arc absorption circuit", "distributed arc absorption circuit" and "filter absorption circuit", please refer to the relevant descriptions in the foregoing embodiments, which will not be repeated here.

[0177] The following examples illustrate possible implementation schemes of the arc discharge protection method described in one or more of the above embodiments.

[0178] This embodiment provides an arc discharge protection method that can be applied to the 48V low-voltage power distribution system of electric vehicles, and can also absorb and protect against transient arcs caused by various types of high-power loads in the vehicle.

[0179] This embodiment provides a method for protecting against electric arc discharge, as detailed below: Figure 6 This is a schematic diagram of the structure of an arc discharge protection system provided in an embodiment of this application, as shown below. Figure 6As shown, the system mainly consists of four parts. The first part is the load classification and identification unit 602, which is used to determine the load status of the vehicle and the power-on logic of the load during power-on and power-off. The second part is the centralized arc processing unit 601, which is used to execute the protection strategy of the centralized arc absorption circuit and is responsible for the passive absorption and corresponding processing strategy of the system arc. The third part is the distributed arc absorption and processing unit 603, which is used to execute the protection strategy of the distributed arc absorption circuit. Different absorption and protection circuits are adopted according to the different arc characteristics generated by different types of loads, and different processing methods are adopted for different levels of loads. The fourth part is the intelligent control monitoring unit 604, which mainly monitors the status of the controller or system, judges based on voltage / current sensor signals, and adopts matching suppression strategies. The 48V load unit 70 is connected to the arc discharge protection system 60 through the 48V load interface on the arc discharge protection system 60. The vehicle control unit 80 is connected to the arc discharge protection system 60 through the communication bus and uploads the status and fault codes of the load through the communication bus.

[0180] A 48V battery is connected to the input terminal of the arc discharge protection system 60 via the main fuse F1. The arc discharge protection system 60 integrates multiple power output channels (corresponding to different loads). Each channel is connected in series with a mechanical relay / contaminator (K1~Kn) and in parallel with a centralized arc absorption circuit. The distributed arc absorption circuit is connected in parallel to the power supply interface of the load, forming an integrated "load-energy absorption terminal" unit with the load.

[0181] like Figure 5 The flowchart shown is a method for determining the load type of a load. The load type is determined by either static configuration identification or dynamic identification.

[0182] The type of load can be identified using a preset load identification (ID), or simply the load identifier. Alternatively, the type of load can be identified by detecting the impedance characteristics of the circuit in which the load is located. For example, measuring the circuit impedance before powering on; if the impedance changes significantly with frequency, it is an inductor; if the impedance is close to zero at low frequencies, it is a capacitor. Alternatively, the type of load can be identified through the current / voltage response curve. For example, after applying a small current excitation, observe the phase difference; inductive load current lags the voltage, while capacitive load current leads the voltage.

[0183] Among them, the method of confirming the type of load by using a preset load ID is called the static configuration identification method; the method of confirming the type of load by detecting the impedance characteristics of the circuit in which the load is located, or by using the current / voltage response curve, is called the dynamic identification method.

[0184] In one optional embodiment, the risk level of the load can be determined based on the load type, rated current, and function of the load. In another optional embodiment, the risk level of the load can be determined based on the arc energy of the electric arc. This embodiment does not particularly limit this approach; the following explanation will use the determination of the load risk level based on the arc energy as an example.

[0185] Among them, high-risk loads can be electric drives and batteries; medium-risk loads can be air conditioning compressors; and low-risk loads can be vehicle lights.

[0186] The logic strategy of the intelligent control monitoring unit 604 adopts a dynamic collaborative control strategy. This unit is mainly responsible for monitoring the working status of each load and controlling the operation of the arc suppression unit based on the load type and arc characteristics.

[0187] For example, S1: During load operation (especially at the moment of power-on and power-off), the circuit parameters are collected in real time by voltage / current sensors, and the contact voltage Vs and load current Is are collected.

[0188] S2: Extract characteristic signals of the electric arc (such as voltage spikes, current change rate, high-frequency oscillations), and calculate the rate of change of voltage (dv / dt) and the rate of change of current (di / dt).

[0189] The voltage change rate can be calculated from the contact voltage Vs; the current change rate can be calculated from the load current.

[0190] S3: Compare the extracted arc feature signal with a preset threshold to determine whether an arc has occurred.

[0191] For example, an arc is determined to occur when dv / dt (i.e., the rate of change of voltage) > a preset rate of change of voltage threshold (e.g., 50V / us) and the load current Is > a preset current threshold (10A).

[0192] Alternatively, an arc can be determined to have occurred when the rate of change of current exceeds a preset threshold for the rate of change of current.

[0193] S4: When an electric arc occurs, the arc energy Earc is calculated based on the arc duration Tarc, the peak voltage Uarc, and the peak current Iarc. The formula for calculating the arc energy Earc can be found in formula (1).

[0194] S5: When an electric arc occurs, based on the load level and the energy generated by the arc, redundant protection (such as high-speed switch disconnection, energy discharge) is immediately triggered, and different protection strategies are adopted: (1) For low-risk loads, use an RC filter absorption circuit (i.e., a resistor-capacitor filter circuit) or an RC filter absorption circuit and a transient voltage suppressor filter absorption circuit. (2) For medium-risk levels, a centralized arc absorption module is used. At this time, the load can be actively limited to reduce the current and adjust the load power. (3) For high-risk levels, active and passive intelligent protection schemes (i.e., protection strategies of centralized arc absorption circuit and protection strategies of distributed arc absorption circuit) are adopted. At the same time, the active clamping circuit is triggered to turn on and cut off the switch of the corresponding load to achieve dual protection of "energy absorption + power outage".

[0195] S6: Reports load status to the vehicle control unit (VCU) in real time, uploads fault codes when a fault occurs, and records event logs for diagnostic purposes.

[0196] like Figure 2 As shown, the centralized arc absorption circuit protection strategy is suitable for medium-risk or high-risk loads. The centralized arc absorption circuit includes: active and passive protection + adaptive matching, passively absorbing arc energy while clamping the voltage to below 60V. The centralized arc absorption circuit mainly consists of three parts: a varistor MOV (i.e., primary protection unit 201), a first transient voltage suppressor TVS1 and an RC absorption circuit (i.e., resistor-capacitor filter circuit), and a MOS clamping circuit (i.e., clamping unit 203), forming a two-stage arc protection absorption circuit.

[0197] The protection strategy of the centralized arc absorption circuit includes: when the load risk level is medium or high risk level: a varistor MOV1 is connected in parallel across the input power supply or the connector to clamp the surge voltage; a TVS1 and an RC absorption circuit (i.e., secondary protection unit 202) are used to suppress high-frequency arc energy; and a MOS active clamping circuit is quickly turned on by an intelligent control unit when an arc occurs, forcibly pulling the contact voltage down to a safe threshold (e.g., less than 60V).

[0198] like Figure 3As shown, the protection strategy of the distributed arc absorption circuit is suitable for high-risk loads. The distributed arc absorption circuit protection strategy consists of a dynamic pre-charge branch composed of a MOSFET array (i.e., switch array 308), a current sampling circuit (i.e., resistor sampling unit 303), a voltage detection circuit 301, a current-limiting resistor unit 304, MOS driver 1 (i.e., first drive circuit 305), MOS driver 2 (i.e., second drive circuit 307), a first switching transistor MOS1 (i.e., first switching transistor unit 306), and a pre-charge capacitor unit (i.e., load 701). The control unit dynamically adjusts the equivalent resistance of the first switching transistor MOS1 by modulating the duty cycle of the PWM signal (i.e., the first control signal h1), thereby achieving closed-loop control of the pre-charge current. This scheme is suitable for loads with large capacitor input terminals, such as motor controllers, DC / DC converters, and supercapacitor modules.

[0199] The protection strategy for the distributed arc absorption circuit involves several key aspects. First, the dynamic pre-charge circuit employs a hybrid series-parallel MOSFET array to balance low resistance and high withstand voltage; the MOSFET array consists of multiple low-internal-resistance MOSFETs connected in parallel. Second, the control circuit utilizes proportional-integral (P)-integral (I) control, fuzzy control, or adaptive control algorithms to achieve closed-loop dynamic adjustment of the PWM. Finally, the current sampling circuit and voltage sampling circuit constitute a dual closed-loop feedback control system, enabling real-time monitoring and adjustment of the pre-charge current and pre-charge voltage.

[0200] like Figure 9 As shown, the strategy for a distributed arc absorption circuit includes the following steps: S901: Identify the operating status and requirements of the load, and set the pre-charge current threshold. S902, Set the PWM duty cycle.

[0201] Setting the PWM duty cycle refers to setting the duty cycle of the first control signal h1, which can be an initial PWM duty cycle.

[0202] S903 detects pre-charge current and pre-charge voltage.

[0203] S904. Determine whether the pre-charge current is less than the pre-charge current threshold. If yes, proceed to step S905; otherwise, proceed to step S911.

[0204] S905. Calculate the difference between the power supply voltage and the precharge voltage.

[0205] S906. Determine whether the first preset condition is met. If yes, proceed to step S907; otherwise, proceed to step S908.

[0206] The determination involves whether the difference between the power supply voltage and the pre-charge voltage meets the first preset condition.

[0207] The first preset condition refers to 5% * the voltage of the first power supply ≤ ≤20%*Voltage of the first power supply.

[0208] Wherein, represents the difference between the power supply voltage and the precharge voltage.

[0209] S907: Increase PWM duty cycle to speed up pre-charging.

[0210] S908. Determine whether the second preset condition is met. If yes, proceed to step S909; otherwise, proceed to step S910.

[0211] The determination involves whether the difference between the power supply voltage and the pre-charge voltage meets the second preset condition.

[0212] The second preset condition refers to, <5%*Voltage of the first power supply.

[0213] S909, Close the pre-charge circuit and open the main circuit.

[0214] S910, The third preset condition is met.

[0215] The third presupposition condition refers to, >20%*Voltage of the first power supply.

[0216] When the third preset condition is met, the PWM duty cycle can be kept unchanged, and step S905 can continue to be executed.

[0217] S911, lower the PWM duty cycle to reduce the precharge current.

[0218] In one embodiment, the strategy of the distributed arc absorption circuit can be based on the arc protection method strategy for capacitive load power-on instantaneous arcing, and is divided into three stages: initial current limiting stage, dynamic acceleration stage, and full conduction stage. During this process, the control circuit adjusts the PWM duty cycle in real time to ensure that the pre-charge current does not exceed the pre-charge current threshold, while simultaneously allowing the pre-charge voltage to smoothly rise to the power supply voltage level (i.e., the voltage of the first power supply V1).

[0219] It should be noted that the precharge voltage rises smoothly to the power supply voltage level, which means that the voltage across the load also rises smoothly to the power supply voltage level.

[0220] The initial current limiting phase, also known as the passive pre-charging phase, specifically includes: A1: When the system is powered on, MOS driver 1 and MOS driver 2 are at low level, and all the first switch MOS1 to the fourth switch MOS4 are turned off. At this time, the current flows through the first power supply V1, the load 701, the sampling resistor Rs and the current limiting resistor R22 to ground GND.

[0221] A2: Because the current-limiting resistor R22 has a large resistance value, the initial surge current will be limited to a very safe low level.

[0222] A3: The current detection device 90 will detect an initial peak current, which will then gradually decrease as the load capacitor is charged. This current is the pre-charge current.

[0223] The dynamic acceleration phase, also known as the active pre-charge phase, specifically includes: B1. The control circuit can dynamically adjust the range of the pre-charge current threshold according to the load operating status and demand, and set the upper limit of the pre-charge current threshold to I. th1 The lower limit of the pre-charge current threshold is I. th2 .

[0224] B2. When the control circuit detects through the current detection device 90 that the current has decreased from the initial peak value to the upper limit of the pre-charge current threshold, Ith1, it automatically reduces the duty cycle of the PWM signal to decrease the pre-charge current. At this time, the control circuit starts to control MOS driver 1 to output the PWM signal with the reduced duty cycle. The total resistance of the pre-charge circuit at this time is R. 总 =R22 / / R eq（MOS1） Among them, R eq（MOS1） This is the equivalent resistance of the first switching transistor MOS1. The equivalent resistance value varies depending on the conduction level of the MOS transistor; see details below. Figure 7 .

[0225] B3: The control circuit forms a closed-loop control system by detecting the pre-charge current, and dynamically adjusts the duty cycle of MOS driver 1.

[0226] B4: The control circuit detects the pre-charge voltage and adjusts the PWM duty cycle according to the relationship between the pre-charge voltage and the power supply voltage (i.e., the voltage of the first power supply V1). When the difference between the power supply voltage and the pre-charge voltage is within the range of [power supply voltage * 5%, power supply voltage * 20%], the control circuit gradually increases the PWM duty cycle to accelerate the charging speed. At this time, the pre-charge current gradually decreases.

[0227] Specifically, the full conduction phase is characterized by: C1: The control circuit detects that the pre-charge current has decreased to the lower limit of the pre-charge current threshold. th2 During this process, the pre-charge current is maintained for pre-charging, that is, the PWM duty cycle is kept constant.

[0228] C2: Simultaneously detects the pre-charge voltage. When the difference between the power supply voltage and the pre-charge voltage is less than 5% of the power supply voltage, the control circuit controls the MOS driver 1 to turn off and outputs a low level, indicating that the pre-charge is complete.

[0229] C3: The control circuit controls MOS driver 2 to output a high level, turning on the second switch MOS2, the third switch MOS3 and the fourth switch MOS4. The load current flows through the low-impedance MOSFET array, and the system enters normal operating mode.

[0230] In another alternative embodiment, the distributed arc absorption circuit can also adopt the traditional TVS array + RC filter absorption scheme. This scheme is mainly used for low-risk loads. This circuit is configured at the load power supply interface to achieve basic protection.

[0231] In summary, this embodiment provides an arc discharge protection method. On the one hand, it can effectively solve the problems of arc discharge generated in 48V power distribution systems by classifying and identifying load types (inductive / capacitive), designing targeted suppression strategies (reverse voltage suppression for inductive loads and surge current limitation for capacitive loads), and combining real-time arc detection and emergency handling mechanisms. This effectively solves the problems of contact damage, device failure, and safety hazards caused by arcs during power-on and power-off of 48V power distribution systems, while also taking into account cost control and system integration.

[0232] On the other hand, it can also be applied to a hybrid 12V and 48V power distribution network architecture to form a systematic arc protection method, realizing a method of active and passive protection + system-level monitoring. The power distribution system is designed in layers through four main unit modules to solve the arc problem caused by frequent switching of electric vehicles in multi-load systems.

[0233] Thirdly, a distributed arc absorption mechanism is adopted to construct an active and passive protection system to absorb arcs generated during the power-on and power-off transitions of inductive loads. Passive absorption involves connecting a TVS diode and an RC snubber network in parallel at the power supply end to quickly clamp voltage spikes. Active protection involves replacing mechanical relays with electronic switches such as MOSFETs or Insulated Gate Bipolar Transistors (IGBTs) to achieve controlled disconnection and avoid arcing at mechanical contacts. A large-capacitor pre-charge circuit is also added at the load front end to prevent electrical sparks caused by excessive transient current during power-on and power-off transitions. Through adaptive adjustment of the load capacitance, a flexible, fast, and safe dynamic pre-charge solution can be applied in different scenarios. Fourthly, a dynamic collaborative control method is adopted, which dynamically adjusts the arc absorption strategy by combining load type, risk level and arc energy. When an arc occurs, the intelligent control unit first uses a distributed arc absorption module and then a centralized arc absorption unit. According to the risk level, the clamping circuit is triggered to form an intelligent collaborative control of "distributed rapid energy absorption + centralized deep arc suppression".

[0234] Fifthly, in response to the increasing popularity of high-power loads such as motor controllers, DC / DC converters, and supercapacitor modules, a dynamic pre-charge scheme using a switching array is adopted. By adjusting the equivalent resistance of the first switching transistor MOS1 through PWM and combining current and voltage dual closed-loop control, a three-stage pre-charge mode is achieved, shortening the pre-charge time and allowing the load voltage to smoothly rise to the power supply voltage level.

[0235] Sixthly, design precautions: adopt a pilot pin design, optimize the insertion and removal method of connectors, and at the same time, consider sufficient creepage distance and good grounding design when designing printed circuit boards.

[0236] It should be noted that although the steps of the method in this application are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps; or steps from different embodiments may be combined into a new technical solution.

[0237] It should be understood that the phrases "one embodiment," "an embodiment," or "some embodiments" mentioned throughout the specification mean that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment," "in one embodiment," or "in some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments are merely for descriptive purposes and do not represent the superiority or inferiority of the embodiments. The descriptions of the various embodiments above tend to emphasize the differences between the various embodiments; their similarities or commonalities can be referred to mutually, and for the sake of brevity, they will not be repeated here.

[0238] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three kinds of relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone.

[0239] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0240] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The embodiments described above are merely illustrative. For example, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple modules or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or modules can be electrical, mechanical, or other forms.

[0241] The modules described above as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules. They may be located in one place or distributed across multiple network units. Some or all of the modules may be selected to achieve the purpose of this embodiment according to actual needs.

[0242] In addition, each functional module in the various embodiments of this application can be integrated into one processing unit, or each module can be a separate unit, or two or more modules can be integrated into one unit; the integrated modules can be implemented in hardware or in the form of hardware plus software functional units.

[0243] The methods disclosed in the several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0244] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0245] The features disclosed in the several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method or device embodiments.

[0246] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of this application are included within the scope of protection of this application.

Claims

1. An electric arc discharge protection method, characterized in that, The method comprises the following steps: During the load operation, an arc characteristic signal generated by the load is acquired; In the case that the arc characteristic signal indicates that the power distribution system generates an arc, arc energy is calculated based on the arc characteristic signal; A risk level of the load is determined according to the arc energy, and a protection strategy corresponding to the power distribution system is matched according to the risk level of the load; Arc discharge protection is performed on the power distribution system based on the protection strategy; The arc energy is calculated based on the arc characteristic signal, comprising: The voltage peak value of the arc and the current peak value of the arc in the arc characteristic signal are acquired; The duration of the arc is acquired; The voltage peak value of the arc and the current peak value of the arc are integrated within the duration to obtain the arc energy; The risk level of the load is determined according to the arc energy, comprising: In the case that the arc energy is in a first set range, the risk level of the load is determined as a low risk level; In the case that the arc energy is in a second set range, the risk level of the load is determined as a medium risk level; In the case that the arc energy is in a third set range, the risk level of the load is determined as a high risk level; The upper limit of the first set range is less than the lower limit of the second set range; the upper limit of the second set range is less than the lower limit of the third set range.

2. The method of arc discharge protection according to claim 1, characterized in that, The arc characteristic signal generated by the load is acquired, comprising: Load current signals and contact voltage signals in the power distribution system are collected; The contact voltage signals are subjected to feature extraction to obtain the voltage peak value of the arc and the voltage change rate; The load current signals are subjected to feature extraction to obtain the current peak value of the arc and the current change rate; The arc characteristic signal is determined according to at least one of the voltage peak value of the arc, the voltage change rate, the current peak value of the arc and the current change rate.

3. The method of arc discharge protection according to claim 2, characterized in that, The method further comprises: In the case that the current change rate is greater than a preset current change rate threshold, it is determined that the arc characteristic signal indicates that the power distribution system generates an arc; or In the case that the voltage change rate is greater than a preset voltage change rate threshold and the amplitude of the load current signal is greater than a preset current threshold, it is determined that the arc characteristic signal indicates that the power distribution system generates an arc.

4. The method of arc discharge protection according to claim 1, characterized in that, The protection strategy corresponding to the power distribution system is matched according to the risk level of the load, comprising: In the case that the risk level of the load is a high risk level, it is determined that the protection strategy comprises a protection strategy of a centralized arc absorption circuit and a protection strategy of a distributed arc absorption circuit; In the case that the risk level of the load is a medium risk level, it is determined that the protection strategy comprises the protection strategy of the centralized arc absorption circuit; In the case that the risk level of the load is a low risk level, it is determined that the protection strategy comprises a protection strategy of a filter absorption circuit.

5. The method of arc discharge protection according to claim 4, characterized in that, The centralized arc absorption circuit comprises a first protection unit, a second protection unit and a clamping unit, and the protection level of the second protection unit is higher than that of the first protection unit; the first protection unit is connected in parallel across the input power supply or connector; the input side of the second protection unit is connected to the output side of the first protection unit, and the output side of the second protection unit is connected to the input side of the clamping unit; the output side of the clamping unit is connected in parallel to the load; wherein: In the case that the risk level of the load is a high risk level or a medium risk level, the protection strategy of the centralized arc absorption circuit comprises: The first protection unit is used for clamping the surge voltage of the input power supply or connector; The second protection unit is used for absorbing the voltage spikes missed by the first protection unit and suppressing high-frequency arc energy; The clamping unit is used for turning on the first transistor in the case of arc generation, so that the contact voltage of the circuit breaker in the power distribution system drops to a safety threshold.

6. The method of arc discharge protection according to claim 4, characterized in that, The distributed arc absorption circuit comprises a pre-charge circuit, and the pre-charge circuit comprises a first switch tube unit, a first drive circuit, a switch array and a second drive circuit; The first end of the load is connected to a first power supply, the second end of the load is connected to the first end of the first switch tube unit, the second end of the first switch tube unit is grounded, the control end of the first switch tube unit is connected to the output end of the first drive circuit, and the input end of the first drive circuit is used for receiving a first control signal; the control end of the switch array is connected to the output end of the second drive circuit; In the case that the risk level of the load is high, the strategy of the distributed arc absorption circuit comprises: When the power distribution system is powered on, the first switch tube unit and the switch array are controlled to be in an off state; According to the working state and demand of the load, a pre-charge current threshold is determined; In the case that the collected pre-charge current is greater than or equal to the pre-charge current threshold, the duty cycle of the first control signal is reduced, and the first drive circuit outputs the first control signal with the reduced duty cycle to control the on or off time of the first switch tube unit, so that the pre-charge current is less than the pre-charge current threshold; In the case that the pre-charge current is less than the pre-charge current threshold, and the difference between the voltage of the first power supply and the collected pre-charge voltage satisfies a first preset condition, the duty cycle of the first control signal is increased to improve the charging speed of the pre-charge circuit; In the case that the pre-charge current is less than the pre-charge current threshold, and the difference between the voltage of the first power supply and the pre-charge voltage satisfies a second preset condition, the first switch tube unit is controlled to be off by the first drive circuit, so that the pre-charge of the pre-charge circuit is completed; and the switch array is controlled to be on by the second drive circuit, so that the load enters a normal working state.

7. The method of arc discharge protection according to claim 4, characterized in that, The filter absorption circuit comprises a resistance-capacitance filter circuit; Alternatively, the filter absorption circuit comprises the resistance-capacitance filter circuit and a transient voltage suppressor.

8. The method of arc discharge protection according to any of claims 1 to 7, characterized in that The method further comprises: obtaining a configuration parameter of the load; determining a load type of the load based on the configuration parameter of the load; wherein the load type comprises a capacitive load and an inductive load.

9. The method of arc discharge protection according to claim 8, characterized in that, The configuration parameter of the load comprises: an identifier of the load; or an impedance characteristic of a loop in which the load is located; or a relationship between a current phase and a voltage phase of the load.

10. A vehicle characterized by comprising: A power distribution system and a control circuit, the power distribution system being connected to the control circuit; wherein the power distribution system comprises at least a circuit breaker and a protection circuit, the protection circuit comprising at least one of: a centralized arc absorption loop, a distributed arc absorption loop, and a filter absorption loop; The control circuit is configured to implement the method of any one of claims 1-9.

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