Circuit for controlling the protection against load dump of a battery management system of a positive electrode and power supply device

Abstract

The application belongs to the technical field of battery control, and particularly relates to a throw load protection circuit based on control of a positive electrode battery management system and a power supply device. The throw load protection circuit is connected in parallel with a charge-discharge control circuit and is arranged between a battery total positive electrode of a starting battery and a battery bus positive electrode. The throw load protection circuit comprises a first unidirectional switch unit, an energy storage unit, a second unidirectional switch unit and a third unidirectional switch unit connected in series. The first unidirectional switch unit is connected with the battery total positive electrode of the starting battery. The third unidirectional switch unit is connected with the battery bus positive electrode of the starting battery. The second unidirectional switch unit and the third unidirectional switch unit are opposite in conduction direction, and can stabilize the voltage between the battery bus positive electrode and the battery bus negative electrode below a preset threshold value at the moment when the charge-discharge control circuit is disconnected, thereby improving the throw load protection effect of the starting battery.

Description

Technical Field

[0001] This application belongs to the field of battery control technology, and in particular relates to a load dump protection circuit and power supply device based on a control positive electrode battery management system. Background Technology

[0002] Currently, vehicle starting batteries typically use lithium batteries. Lithium battery packs have overcharge and over-discharge protection. When the voltage platform of a single lithium battery cell exceeds a threshold (e.g., 3.6V), the lithium battery pack will activate overcharge protection, preventing the vehicle's alternator from charging the lithium battery pack. However, the vehicle's alternator continues to generate electricity, and the generated electricity cannot charge the lithium battery pack. This causes a voltage spike on the vehicle's controller, triggering an overvoltage protection state. This can prevent the vehicle from starting normally, affect the normal operation of onboard equipment, or even cause overvoltage damage. Therefore, a circuit is needed to provide load dump protection for the starting battery.

[0003] Chinese patent CN222147192U discloses a load dump protection circuit for a starting battery. A control circuit is connected in series between the battery's total negative terminal and the battery bus negative terminal. The control circuit includes a charging switch. The load dump protection circuit is connected in parallel with the control circuit and includes a series-connected energy storage unit and a unidirectional switching unit. The positive terminals of the unidirectional switching unit and the energy storage unit are close to the battery's total negative terminal relative to the negative terminal. This ensures that when the charging switch is turned off, the load dump protection circuit and the starting battery form a freewheeling circuit in series, and the energy storage unit absorbs energy, thereby stabilizing the voltage between the battery bus positive terminal and the battery bus negative terminal below a preset threshold. However, this load dump protection circuit is based on controlling the negative terminal, which may lead to protection failure due to incomplete disconnection of the grounding path. Furthermore, it may introduce safety hazards (such as leakage risk) in high-voltage scenarios, resulting in poor protection performance.

[0004] Therefore, improving the load dump protection effect of the starting battery has become an urgent problem to be solved. Utility Model Content

[0005] This application provides a load dump protection circuit and power supply device based on a control positive electrode battery management system, which aims to improve the load dump protection effect of the starting battery.

[0006] In a first aspect, embodiments of this application provide a load dumping protection circuit based on a control positive electrode battery management system, which is connected in parallel with a charge and discharge control circuit and is disposed between the main positive electrode of the starting battery and the positive electrode of the battery bus.

[0007] The load dump protection circuit includes a first unidirectional switch unit, an energy storage unit, a second unidirectional switch unit, and a third unidirectional switch unit connected in series. The first unidirectional switch unit is connected to the positive terminal of the starting battery. The third unidirectional switch unit is connected to the positive terminal of the starting battery bus. The second unidirectional switch unit and the third unidirectional switch unit have opposite conduction directions.

[0008] In one possible implementation, the load dump protection circuit further includes a first discharge resistor connected in parallel with the energy storage unit.

[0009] In one possible implementation, the energy storage unit is connected to the charge / discharge control circuit via a discharge switch and a second discharge resistor;

[0010] The first end of the discharge switch is connected to the energy storage unit, the second end is connected to one end of the second discharge resistor, and the other end of the second discharge resistor is connected to the charge and discharge control circuit.

[0011] In one possible implementation, the charge / discharge control circuit includes a fourth unidirectional switch unit and a fifth unidirectional switch unit connected in series, wherein the fourth unidirectional switch unit is connected to the positive terminal of the battery and the fifth unidirectional switch unit is connected to the positive terminal of the battery bus.

[0012] The other end of the second bleeder resistor is connected between the fourth unidirectional switch unit and the fifth unidirectional switch unit.

[0013] In one possible implementation, each of the unidirectional switching units is a diode and a switch, or a MOSFET, connected in parallel.

[0014] In one possible implementation, the first unidirectional switching unit includes a first diode and a first switch connected in parallel, the second unidirectional switching unit includes a second diode and a second switch connected in parallel, and the third unidirectional switching unit includes a third diode and a third switch connected in parallel.

[0015] The first end of the first diode is connected to the energy storage unit, and the second end is connected to the positive terminal of the battery; the first end of the second diode is connected to the energy storage unit, and the second end is connected to the third unidirectional switch unit; the first end of the third diode is connected to the positive terminal of the battery bus, and the second end is connected to the second unidirectional switch unit.

[0016] In one possible implementation, the fourth unidirectional switching unit includes a fourth diode and a fourth switch connected in parallel, and the fifth unidirectional switching unit includes a fifth diode and a fifth switch connected in parallel.

[0017] The first end of the fourth diode is connected to the positive terminal of the battery, and the second end is connected to the fifth unidirectional switch unit; the first end of the fifth diode is connected to the positive terminal of the battery bus, and the second end is connected to the fourth unidirectional switch unit.

[0018] In one possible implementation, the energy storage unit is a capacitor.

[0019] Secondly, embodiments of this application provide a power supply device, including a starter battery, a charge / discharge control circuit, a battery management module, and a load dump protection circuit. The charge / discharge control circuit is connected in series between the main positive terminal of the starter battery and the positive terminal of the battery bus. The battery management module is connected to the control terminal of the charge / discharge control circuit. The load dump protection circuit is the load dump protection circuit as described in the first aspect or any of the implementations thereof.

[0020] In one possible implementation, a current detection circuit is connected in series between the main negative terminal of the starting battery and the negative terminal of the battery bus, and the battery management module is connected to the control terminal of the current detection circuit.

[0021] The beneficial effects of this application embodiment compared with the prior art are as follows: When charging the starter battery, at the instant the charge / discharge control circuit is disconnected, a freewheeling circuit is formed between the load dump protection circuit and the starter battery, and the energy storage unit absorbs energy, thereby stabilizing the voltage between the positive and negative terminals of the battery bus below a preset threshold, ensuring normal vehicle start-up and normal operation of on-board equipment; In addition, the load dump protection circuit provided in this application is based on the control of the positive battery management system, which effectively avoids the problems of protection failure due to incomplete disconnection of the grounding path, or the introduction of safety hazards (such as leakage risk) in high-voltage scenarios, which exist in the load dump protection circuit based on the control of the negative battery management system, thus improving the load dump protection effect of the starter battery; Furthermore, the design of the unidirectional switching unit in the load dump protection circuit provided in this application ensures that the energy storage unit can absorb energy only when all unidirectional switching units in the load dump protection circuit are fully turned on, so that when charging the starter battery through the charge / discharge control circuit, the energy does not pass through the load dump protection circuit, reducing energy loss and improving energy utilization and charging efficiency. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1A schematic diagram of a load dump protection circuit based on a control of a positive electrode battery management system is provided in one embodiment of this application;

[0024] Figure 2 This is a schematic diagram of the structure of a power supply device provided in one embodiment of this application;

[0025] Figure 3 A schematic diagram of the current flow direction during the operation of a load dump protection circuit 10 provided in an embodiment of this application;

[0026] Figure 4 This is a schematic diagram showing the current flow direction during another operation of the load dump protection circuit 10 provided in one embodiment of this application;

[0027] Figure 5 This is a schematic diagram showing the current flow direction during another operation of the load dump protection circuit 10 provided in an embodiment of this application. Detailed Implementation

[0028] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0029] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0030] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0031] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0032] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0034] For ease of understanding, the technical solution of this application will be described in detail below with reference to the accompanying drawings.

[0035] Figure 1 A schematic diagram of a load dump protection circuit based on a control of a positive electrode battery management system is provided in one embodiment of this application, as shown below. Figure 1 As shown, for ease of explanation, only the parts relevant to this embodiment are shown. The load dumping protection circuit 10 is connected in parallel with the charge and discharge control circuit 20 and is disposed between the battery total positive terminal B+ and the battery bus positive terminal P+ of the starting battery 30.

[0036] The load dump protection circuit 10 includes a first unidirectional switch unit SK1, an energy storage unit C, a second unidirectional switch unit SK2, and a third unidirectional switch unit SK3 connected in series. The first unidirectional switch unit SK1 is connected to the positive terminal B+ of the starting battery 30. The third unidirectional switch unit is connected to the positive terminal P+ of the starting battery 30. The conduction directions of the second and third unidirectional switch units are opposite.

[0037] In this embodiment, an example of the load dump protection circuit provided in this application is given. The design of the first unidirectional switch unit SK1 can prevent the discharge current from flowing through the load dump protection circuit 10 when the starting battery 30 is discharging by keeping the first switch S1 open, thereby reducing the loss of discharge current and improving the utilization rate of discharge current. The design of the second unidirectional switch unit SK2 and the third unidirectional switch unit SK3 can prevent the charging current from passing through the second unidirectional switch unit SK2 and the third unidirectional switch unit SK3 to charge the energy storage unit C when the starting battery 30 is being charged by keeping the second switch S2 and the third switch S3 open, thereby reducing the loss of charging current and improving the utilization rate and charging efficiency of charging current.

[0038] For example, see Figure 1 The first unidirectional switching unit SK1 is connected to the positive terminal B+ of the battery. The first unidirectional switching unit SK1, the energy storage unit C, the second unidirectional switching unit SK2 and the third unidirectional switching unit SK3 are connected in series. The third unidirectional switching unit SK3 is connected to the positive terminal P+ of the battery bus. The unidirectional conduction direction of the second unidirectional switching unit SK2 is opposite to the conduction direction of the third unidirectional switching unit SK3.

[0039] It should be noted that, Figure 1 The positional relationship between the second unidirectional switching unit SK2 and the third unidirectional switching unit SK3 shown is merely an example. The positions of the second unidirectional switching unit SK2 and the third unidirectional switching unit SK3 can be interchanged, as long as the unidirectional conduction direction of the second unidirectional switching unit SK2 is opposite to the conduction direction of the third unidirectional switching unit SK3. Furthermore, the load dump protection circuit 10 can... Figure 1 Based on the above, more unidirectional switch units are connected in series. The unidirectional conduction direction of the added unidirectional switch units is not required.

[0040] In one possible implementation, the load dump protection circuit 10 further includes a first discharge resistor R1 connected in parallel with the energy storage unit C. The first discharge resistor R1 is used to discharge the energy in the energy storage unit C, which is a capacitor.

[0041] As an example, after the car generator has finished regulating and the voltage has dropped, the voltage of the energy storage unit C is quickly discharged through the first discharge resistor R1, thereby accelerating the discharge speed of the energy storage unit C.

[0042] For example, the resistance of the first bleeder resistor R1 is from 1 kΩ to 10 kΩ. Of course, the resistance of the first bleeder resistor R1 is not limited to this and can be set according to actual needs. This application does not limit this.

[0043] In one possible implementation, the energy storage unit C is connected to the charge / discharge control circuit 20 via a discharge switch SW and a second discharge resistor R2; the first end of the discharge switch SW is connected to the energy storage unit C, the second end is connected to one end of the second discharge resistor R2, and the other end of the second discharge resistor R2 is connected to the charge / discharge control circuit 20.

[0044] It is understood that the positions of the discharge switch SW and the second discharge resistor R2 can be interchanged, that is, one end of the second discharge resistor R2 is connected to the energy storage unit C, and the other end is connected to the first end of the discharge switch SW, and the second end of the discharge switch SW is connected to the charge and discharge control circuit 20. This application does not limit this.

[0045] For example, the discharge switch SW is a diode.

[0046] Based on the above design, the energy in the energy storage unit C can be discharged through the first discharge resistor R1, the charge and discharge control circuit 20, or both, thereby improving the efficiency and flexibility of energy discharge.

[0047] In one possible implementation, the charge / discharge control circuit 20 includes a fourth unidirectional switch unit SK4 and a fifth unidirectional switch unit SK5 connected in series. The fourth unidirectional switch unit SK4 is connected to the battery's total positive terminal B+, and the fifth unidirectional switch unit SK5 is connected to the battery's bus positive terminal P+.

[0048] Specifically, the fourth unidirectional switching unit SK4 is a charging control switching circuit, and the fifth unidirectional switching unit SK5 is a discharging control switching circuit.

[0049] As an example, when the first terminal of the discharge switch SW is connected to the energy storage unit C and the second terminal is connected to one end of the second discharge resistor R2, the other end of the second discharge resistor R2 is connected between the fourth unidirectional switch unit SK4 and the fifth unidirectional switch unit SK5.

[0050] As another example, when one end of the second discharge resistor R2 is connected to the energy storage unit C and the other end is connected to the first end of the discharge switch SW, the second end of the discharge switch SW is connected between the fourth unidirectional switch unit SK4 and the fifth unidirectional switch unit SK5.

[0051] In one possible implementation, each of the aforementioned unidirectional switching units SK is a diode D and a switch S connected in parallel, or a MOSFET. The switch S is a single-pole single-throw switch.

[0052] As an example, the first unidirectional switching unit SK1 includes a first diode D1 and a first switch S1 connected in parallel, the second unidirectional switching unit SK2 includes a second diode D2 and a second switch S2 connected in parallel, and the third unidirectional switching unit SK3 includes a third diode D3 and a third switch S3 connected in parallel.

[0053] Specifically, the first terminal of the first diode D1 is connected to the energy storage unit C, and the second terminal is connected to the positive terminal B+ of the battery; the first terminal of the second diode D2 is connected to the energy storage unit C, and the second terminal is connected to the third unidirectional switch unit SK3; the first terminal of the third diode D3 is connected to the positive terminal P+ of the battery bus, and the second terminal is connected to the second unidirectional switch unit SK2.

[0054] As an example, the fourth unidirectional switching unit SK4 includes a fourth diode D4 and a fourth switch S4 connected in parallel, and the fifth unidirectional switching unit SK5 includes a fifth diode D5 and a fifth switch S5 connected in parallel.

[0055] Specifically, the first terminal of the fourth diode D4 is connected to the positive terminal B+ of the battery, and the second terminal is connected to the fifth unidirectional switching unit SK5; the first terminal of the fifth diode D5 is connected to the positive terminal P+ of the battery bus, and the second terminal is connected to the fourth unidirectional switching unit SK4.

[0056] As another example, any one or more of the unidirectional switching units SK mentioned above are MOSFETs.

[0057] For example, when the first unidirectional switching unit SK1 is a P-channel metal-oxide-semiconductor (PMOS), its source is connected to the positive terminal B+ of the battery, its drain is connected to the energy storage unit C, and its gate is connected to the controller of the battery management system.

[0058] The technical solution provided in this application can form a freewheeling circuit between the load dump protection circuit and the starting battery at the instant the charge / discharge control circuit is disconnected during the charging of the starting battery. The energy storage unit absorbs energy, thereby stabilizing the voltage between the positive and negative terminals of the battery bus below a preset threshold, ensuring normal vehicle starting and normal operation of on-board equipment. In addition, the load dump protection circuit provided in this application is based on the control of the positive battery management system, which effectively avoids the problems of protection failure due to incomplete disconnection of the grounding path or the introduction of safety hazards (such as leakage risk) in high-voltage scenarios, which exist in load dump protection circuits based on the control of the negative battery management system, thus improving the load dump protection effect of the starting battery. Furthermore, the design of the unidirectional switching unit in the load dump protection circuit provided in this application ensures that the energy storage unit can absorb energy only when all unidirectional switching units in the load dump protection circuit are fully turned on. This means that when the starting battery is charged through the charge / discharge control circuit, energy does not pass through the load dump protection circuit, reducing energy loss and improving energy utilization and charging efficiency.

[0059] Figure 2 This is a schematic diagram of a power supply device according to an embodiment of this application. Based on the above embodiment, this embodiment further explains and optimizes the technical solution. Specifically, as shown below... Figure 2 As shown, the power supply device includes a starter battery 30, a charge / discharge control circuit 20, a battery management module 40, and a load dump protection circuit 10. The charge / discharge control circuit 20 is connected in series between the main positive terminal B+ of the starter battery 30 and the positive terminal P+ of the battery bus. The battery management module 40 is connected to the control terminal of the charge / discharge control circuit 20. The battery management module 40 is based on controlling the positive terminal.

[0060] Specifically, the load dump protection circuit 10 is connected in parallel with the charge / discharge control circuit 20, including a first unidirectional switch unit SK1, an energy storage unit C, a second unidirectional switch unit SK2, and a third unidirectional switch unit SK3 connected in series. The charge / discharge control circuit 20 includes a fourth unidirectional switch unit SK4 and a fifth unidirectional switch unit SK5 connected in series. The fourth unidirectional switch unit SK4 is a charging control switch circuit, and the fifth unidirectional switch unit SK5 is a discharging control switch circuit. When the starter battery 30 is being charged, at the instant the fourth unidirectional switch unit SK4 is disconnected, the load dump protection circuit 10 and the starter battery 30 are connected in series to form a freewheeling circuit, and the energy storage unit C absorbs energy, thereby stabilizing the voltage between the positive terminal P+ and the negative terminal P- of the battery bus below a preset threshold.

[0061] For example, the preset threshold is 32 volts (V). Of course, this preset threshold can also be fine-tuned by adjusting the parameters of the energy storage unit C, and this application does not limit it in this way.

[0062] In one possible implementation, a current detection circuit 50 is connected in series between the battery's total negative terminal B- and the battery bus negative terminal P-, and the battery management module 40 is connected to the control terminal of the current detection circuit 50.

[0063] Specifically, based on Figure 2 The power supply device shown, Figures 3 to 5 The current flow direction of the load dump protection circuit 10 provided in this application is described in different operating processes:

[0064] refer to Figure 3 When charging does not exceed the overcharge protection limit, the battery management module 40 controls the fourth switch S4 in the fourth unidirectional switch unit SK4 to remain closed, and controls all unidirectional switch units SK in the load dump protection circuit 10 to remain open. Current I flows from the positive terminal P+ of the battery bus through the fifth diode D5 in the fifth unidirectional switch unit SK5 and the closed fourth switch S4 in the fourth unidirectional switch unit SK4 to the total positive terminal B+ of the battery. The charge / discharge control circuit 20 and the starting battery 30 are connected in series to form a charging circuit. At this time, in the load dump protection circuit 10, since all the unidirectional switch units SK are not closed, and due to the unidirectional conductivity of the second diode D2 in the second unidirectional switch unit SK2, current I cannot pass through the load dump protection circuit 10, effectively avoiding energy waste during charging and improving energy utilization and charging efficiency.

[0065] refer to Figure 4When charging triggers overcharge protection, the battery management module 40 triggers overvoltage protection, thereby shutting off the fourth switch S4 in the fourth unidirectional switch unit SK4 and controlling all unidirectional switch units in the load dump protection circuit 10 to close. At this time, the current I flows from the positive terminal P+ of the battery bus through the third unidirectional switch unit SK3, the second unidirectional switch unit SK2, the energy storage unit C, and the first unidirectional switch unit SK1 to the total positive terminal B+ of the battery. The load dump protection circuit 10 and the starting battery 30 are connected in series to form a freewheeling circuit, and start charging the energy storage unit C, thereby stabilizing the voltage between the positive terminal P+ of the battery bus and the negative terminal P- of the battery bus below the preset threshold.

[0066] refer to Figure 5 When overcharge protection recovery is triggered during charging, the battery management module 40 controls the fourth switch S4 in the fourth unidirectional switch unit SK4 to close and open the switches in all unidirectional switch units SK in the load dump protection circuit 10. Current I flows from the positive terminal P+ of the battery bus through the fifth diode D5 in the fifth unidirectional switch unit SK5 and the closed fourth switch S4 in the fourth unidirectional switch unit to the total positive terminal B+ of the battery. At this time, the energy of the energy storage unit C in the load dump protection circuit 10 can be discharged through the first discharge resistor R1. Current I is released from the positive terminal of the energy storage unit C through the first discharge resistor R1 to the negative terminal of the energy storage unit C. The charge in the energy storage unit C is quickly discharged by the first discharge resistor R1 to prevent the voltage stability between the positive terminal P+ and the negative terminal P- of the battery bus from being affected when the energy storage unit C is discharged. Alternatively, the energy of the energy storage unit C in the load dump protection circuit 10 can be quickly discharged through the charge and discharge control circuit 20. Current I passes through the discharge switch SW and the second discharge resistor R2 and is gradually released from the charge and discharge control circuit 20.

[0067] In summary, when the starting battery 30 is charged, the moment the fourth switch S4 in the fourth unidirectional switch unit SK4 is opened, the switches of all unidirectional switch units SK in the load dump protection circuit 10 are closed, so that the energy storage unit C in the load dump protection circuit 10 is connected in series with the starting battery 30 to form a freewheeling circuit to absorb excess energy, and the voltage between the positive terminal P+ and the negative terminal P- of the battery bus is stabilized below the preset threshold. When the fourth switch S4 in the fourth unidirectional switch unit SK4 is restored, the switches of all unidirectional switch units SK in the load dump protection circuit 10 are opened, and the energy storage unit C in the load dump protection circuit 10 is quickly discharged through the first discharge resistor R1 and / or the charge and discharge control circuit 20, ensuring that the vehicle starts normally and the on-board equipment works normally.

[0068] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A load dump protection circuit based on a control of a positive electrode battery management system, characterized in that, It is connected in parallel with the charge and discharge control circuit and is located between the main positive terminal of the starting battery and the positive terminal of the battery bus. The load dump protection circuit includes a first unidirectional switch unit, an energy storage unit, a second unidirectional switch unit, and a third unidirectional switch unit connected in series. The first unidirectional switch unit is connected to the positive terminal of the starting battery. The third unidirectional switch unit is connected to the positive terminal of the starting battery bus. The second unidirectional switch unit and the third unidirectional switch unit have opposite conduction directions.

2. The load dump protection circuit according to claim 1, characterized in that, The load dump protection circuit also includes a first discharge resistor connected in parallel with the energy storage unit.

3. The load dump protection circuit according to claim 2, characterized in that, The energy storage unit is connected to the charge and discharge control circuit via a discharge switch and a second discharge resistor. The first end of the discharge switch is connected to the energy storage unit, the second end is connected to one end of the second discharge resistor, and the other end of the second discharge resistor is connected to the charge and discharge control circuit.

4. The load dump protection circuit according to claim 3, characterized in that, The charging and discharging control circuit includes a fourth unidirectional switch unit and a fifth unidirectional switch unit connected in series. The fourth unidirectional switch unit is connected to the positive terminal of the battery, and the fifth unidirectional switch unit is connected to the positive terminal of the battery bus. The other end of the second bleeder resistor is connected between the fourth unidirectional switch unit and the fifth unidirectional switch unit.

5. The load dump protection circuit according to claim 4, characterized in that, Each of the unidirectional switching units is a diode and a switch connected in parallel, or a MOSFET.

6. The load dump protection circuit according to claim 5, characterized in that, The first unidirectional switching unit includes a first diode and a first switch connected in parallel; the second unidirectional switching unit includes a second diode and a second switch connected in parallel; and the third unidirectional switching unit includes a third diode and a third switch connected in parallel. The first end of the first diode is connected to the energy storage unit, and the second end is connected to the positive terminal of the battery; the first end of the second diode is connected to the energy storage unit, and the second end is connected to the third unidirectional switch unit; the first end of the third diode is connected to the positive terminal of the battery bus, and the second end is connected to the second unidirectional switch unit.

7. The load dump protection circuit according to claim 5, characterized in that, The fourth unidirectional switching unit includes a fourth diode and a fourth switch connected in parallel, and the fifth unidirectional switching unit includes a fifth diode and a fifth switch connected in parallel; The first end of the fourth diode is connected to the positive terminal of the battery, and the second end is connected to the fifth unidirectional switch unit; the first end of the fifth diode is connected to the positive terminal of the battery bus, and the second end is connected to the fourth unidirectional switch unit.

8. The load dump protection circuit according to any one of claims 1 to 7, characterized in that, The energy storage unit is a capacitor.

9. A power supply device, characterized in that, The device includes a starter battery, a charge / discharge control circuit, a battery management module, and a load dump protection circuit. The charge / discharge control circuit is connected in series between the main positive terminal of the starter battery and the positive terminal of the battery bus. The battery management module is connected to the control terminal of the charge / discharge control circuit. The load dump protection circuit is the load dump protection circuit as described in any one of claims 1 to 8.

10. The power supply device according to claim 9, characterized in that, A current detection circuit is connected in series between the main negative terminal of the starting battery and the negative terminal of the battery bus, and the battery management module is connected to the control terminal of the current detection circuit.

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