Protective device of direct current converter

Abstract

The utility model relates to a protection device of a direct-current converter. The protection device comprises a pre-charging module; the pre-charging module is respectively coupled with the battery pack and the direct-current converter; and the pre-charging module is used for reducing the voltage input by the battery pack within a preset time period after the direct-current converter is connected with the battery pack through the protection device. According to the invention, the risk of failure of the DC converter due to surge can be reduced, and the safety of the whole vehicle is improved.

Description

Technical Field

[0001] This application relates to the field of new energy technology, specifically to a protection device for a DC converter. Background Art

[0002] With the rapid development of new energy technologies, battery-powered new energy vehicles are becoming increasingly popular. In these vehicles, the DC-DC converter is a crucial component, converting the energy from a high-voltage DC battery into energy suitable for low-voltage DC appliances. For example, the voltage range of the power battery in a pure electric commercial vehicle is between 480V and 700V, while the voltage needed to power the electronic control unit, multimedia system, instrument panel, and lighting equipment needs to be reduced to 24V.

[0003] Currently, there are surges during vehicle startup and relay closure. These surges can cause DC-DC converter failures, affecting the safety of the entire vehicle. Utility Model Content

[0004] In view of the above problems, this application provides a protection device for DC converter, which can reduce the risk of DC converter failure due to surge and provide the safety of the whole vehicle.

[0005] In a first aspect, this application provides a protection device for a DC-DC converter. The protection device includes a pre-charge module; the pre-charge module is coupled to both a battery pack and the DC-DC converter; the pre-charge module is used to reduce the input voltage of the battery pack during a preset period after the DC-DC converter is connected to the battery pack through the protection device.

[0006] The protective device provided in this application embodiment can reduce the input voltage of the battery pack for a period of time after the DC converter is connected to the battery pack, thereby reducing the risk of the DC converter failing due to high voltage and high current surges, and thus improving the safety of the whole vehicle.

[0007] In some embodiments, the protection device further includes a surge absorption module; the surge absorption module is disposed between the battery pack and the precharge module; the surge absorption module is used to absorb differential-mode surges and common-mode surges input to the battery pack. In the technical solution of this application embodiment, the protection device can reduce the input voltage of the battery pack for a period of time after the DC-DC converter is connected to the battery pack, and absorb surges throughout the connection process between the DC-DC converter and the battery pack, thereby reducing the risk of DC-DC converter failure due to surges, and thus improving the safety of the entire vehicle.

[0008] In some embodiments, the protection device further includes a surge absorption module; the surge absorption module is disposed between the precharge module and the DC-DC converter; the surge absorption module is used to absorb differential-mode surges and common-mode surges input to the battery pack. In the technical solution of this application embodiment, the protection device can reduce the input voltage of the battery pack for a period of time after the DC-DC converter is connected to the battery pack, and absorb surges throughout the connection process between the DC-DC converter and the battery pack, thereby reducing the risk of DC-DC converter failure due to surges, and thus improving the safety of the entire vehicle.

[0009] In some embodiments, the pre-charge module includes a positive protection switch, a negative protection switch, and a pre-charge circuit. A first terminal of the positive protection switch is connected to the positive input terminal of the pre-charge module, and a second terminal of the positive protection switch is connected to the first terminal of the pre-charge circuit. The second terminal of the pre-charge circuit is connected to the positive output terminal of the pre-charge module. A first terminal of the negative protection switch is connected to the positive input terminal of the pre-charge module, and a second terminal of the negative protection switch is connected to the negative output terminal of the pre-charge module. The positive and negative protection switches are used to close after the pre-charge module is connected to the battery pack. The pre-charge circuit is used to reduce the input voltage of the battery pack within a preset time period after the positive protection switch closes. This embodiment employs a positive and negative protection switch, which can protect the operator and reduce safety hazards caused by surges generated at the moment the protection device is activated. The pre-charge circuit reduces the input voltage of the battery pack within a preset time period after the positive protection switch closes, thereby reducing the voltage transmitted to the DC-DC converter during the initial connection period, protecting the DC-DC converter, and improving its safety.

[0010] In some embodiments, the pre-charging circuit includes a pre-charging resistor, a first switch, a second switch, and a control circuit. A first terminal of the pre-charging resistor is connected to a second terminal of the positive protection switch, and a second terminal of the pre-charging resistor is connected to a first terminal of the first switch. The second terminal of the first switch is connected to both the control circuit and the positive output terminal of the pre-charging module. A first terminal of the second switch is connected to a second terminal of the positive protection switch, and a second terminal of the second switch is connected to the positive output terminal of the pre-charging module. The control circuit is connected to both the first and second switches. The control circuit controls the first switch to open and the second switch to close after detecting that the voltage of the pre-charging resistor has reached a preset voltage. In this embodiment, by detecting whether the voltage of the pre-charging resistor has reached a preset voltage, if the voltage of the pre-charging resistor has not reached the preset voltage, the first switch closes and the second switch opens, resulting in a reduced voltage output by the pre-charging module. If the voltage of the pre-charging resistor reaches the preset voltage, the control circuit controls the first switch to open and the second switch to close, allowing the voltage input to the battery pack to be directly output from the pre-charging module output terminal. The pre-charging circuit has a simple structure and easy-to-implement control logic. It can also reduce the voltage transmitted to the DC-DC converter during the initial connection period, thereby protecting the DC-DC converter and improving its safety.

[0011] In some embodiments, the control circuit includes a microcontroller unit and a power supply circuit; the power supply circuit is connected to the positive output terminal of the first switch, the microcontroller unit, and the precharge module, respectively; the microcontroller unit is also connected to the first switch and the second switch, respectively; the power supply circuit is used to supply power to the microcontroller unit after the positive protection switch is closed; the microcontroller unit is used to control the first switch to open and the second switch to close after detecting that the voltage of the precharge resistor reaches a preset voltage. This embodiment uses a microcontroller unit for control, resulting in a simple control circuit structure, easy-to-implement control logic, and the ability to reduce the voltage transmitted to the DC-DC converter during the initial connection period, thereby protecting the DC-DC converter.

[0012] In some embodiments, the power supply circuit includes a first voltage divider resistor, a second voltage divider resistor, and an energy storage capacitor. A first terminal of the first voltage divider resistor is connected to a second terminal of a first switch, and a second terminal of the first voltage divider resistor is connected to a first terminal of the second voltage divider resistor. The second terminal of the second voltage divider resistor is grounded. The common terminal of the first and second voltage divider resistors is connected to the first terminals of the microcontroller unit and the energy storage capacitor, respectively. The second terminal of the energy storage capacitor is grounded. In this embodiment, the first and second voltage divider resistors are used to power the microcontroller unit during the pre-charging stage, and the energy storage capacitor is used in subsequent stages. The power supply circuit is easy to implement and relatively stable, enabling the microcontroller unit to operate stably, thereby ensuring the stable operation of the protective device.

[0013] In some embodiments, the surge absorption module includes a first absorption circuit and a second absorption circuit interconnected. The input terminal of the first absorption circuit is connected to the input terminal of the surge absorption module, and the output terminal of the second absorption circuit is connected to the output terminal of the surge absorption module. The first absorption circuit is used to absorb differential-mode surges and common-mode surges; the second absorption circuit is used to absorb differential-mode surges and common-mode surges again. This embodiment employs a first absorption circuit and a second absorption circuit to perform two-stage absorption of surges input to the battery pack, which can absorb more surges, thereby reducing the risk of DC-DC converter failure due to surges.

[0014] In some embodiments, the first absorption circuit includes a first varistor, a second varistor, a third varistor, and a discharge tube. The two ends of the first varistor are connected to the positive and negative input terminals of the surge absorption module, respectively. The first end of the second varistor is connected to the positive input terminal of the surge absorption module, and the second end of the second varistor is connected to the first end of the third varistor. The second end of the third varistor is connected to the negative input terminal of the surge absorption module. The first end of the discharge tube is connected to the common terminal of the second and third varistors, and the second end of the discharge tube is grounded. This embodiment uses a first varistor to absorb differential-mode surges and a second varistor, a third varistor, and a discharge tube to absorb common-mode surges, thus comprehensively and fully absorbing surges input from the battery pack and reducing the risk of DC-DC converter failure due to surges.

[0015] In some embodiments, the second absorption circuit includes a first Y capacitor, a second Y capacitor, a thermistor, a differential-mode inductor, a common-mode inductor, multiple bleeder resistors, and an absorption capacitor; the first terminal of the first Y capacitor is connected to the positive input terminal of the surge absorption module, the second terminal of the first Y capacitor is connected to the first terminal of the second Y capacitor, and the common terminal of the first Y capacitor and the second Y capacitor is grounded; the second terminal of the second Y capacitor is connected to the negative input terminal of the surge absorption module; the first terminal of the thermistor is connected to the positive input terminal of the surge absorption module, and the second terminal of the thermistor is connected to the first terminal of the differential-mode inductor; the second terminal of the differential-mode inductor is connected to the first terminal of the common-mode inductor; the second terminal of the common-mode inductor is connected to the negative input terminal of the surge absorption module, the third terminal of the common-mode inductor is connected to the positive output terminal of the surge absorption module, and the fourth terminal of the common-mode inductor is connected to the negative output terminal of the surge absorption module; the multiple bleeder resistors are connected in series to form a series circuit, and the two ends of the series circuit are respectively connected to the positive output terminal and the negative output terminal of the surge absorption module; the two ends of the absorption capacitor are respectively connected to the positive output terminal and the negative output terminal of the surge absorption module. In this embodiment, based on the surge absorption performed in the first absorption circuit, a thermistor, differential-mode inductor, absorption capacitor, and bleeder resistor are used to absorb differential-mode surges, and a first Y capacitor, a second Y capacitor, and a common-mode inductor are used to absorb common-mode surges. In this way, differential-mode surges and common-mode surges can be further suppressed, thereby greatly reducing the risk of DC converter failure due to surges and providing more effective protection for the DC converter.

[0016] In some embodiments, the protective device further includes a fuse module; the input terminal of the fuse module is connected to the battery pack, and the output terminal of the fuse module is connected to the input terminal of the precharge module or surge absorption module; the fuse module is used to blow when the voltage input to the battery pack exceeds a preset voltage threshold, cutting off the path between the battery pack and the DC-DC converter. In this embodiment, when the protective device is assembled with the battery pack or junction box, large current or voltage surges may occur, and the fuse module can improve the safety of the assembly process.

[0017] In some embodiments, the insurance module, pre-charge module, and surge absorption module are assembled and connected via connectors. This connection method provided in this application embodiment simplifies assembly and disassembly, allows for flexible combination of multiple modules, and enables module expansion based on this method. This allows the protective device to meet the needs of various products and expands its application scenarios.

[0018] In some embodiments, the insurance module, precharge module, and surge absorption module all include a module housing, and the connectors include a connection button, a knob, and a nut; the connection button and knob are located on a first side of the module housing, and the nut is located on a second side of the module housing. This embodiment uses a knob and nut for connection, which facilitates assembly, disassembly, and replacement.

[0019] In some embodiments, the protective device further includes a device housing and a heat sink; the safety module, precharge module, and surge absorption module are disposed within the device housing, and the heat sink is disposed on the outer surface of the device housing. This application embodiment uses a device housing to protect multiple internal modules and employs a heat sink to improve the heat dissipation performance of the protective device, thereby enhancing its safety. Attached Figure Description

[0020] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the alternative embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0021] Figure 1 This is one of the structural schematic diagrams of a protection device for a DC-DC converter according to an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of the connection relationship of the protective device according to an embodiment of this application;

[0023] Figure 3 This is a second schematic diagram of the structure of a protection device for a DC-DC converter according to an embodiment of this application;

[0024] Figure 4 This is a third schematic diagram of the structure of a protection device for a DC-DC converter according to an embodiment of this application;

[0025] Figure 5 This is one of the structural schematic diagrams of a pre-charge module according to an embodiment of this application;

[0026] Figure 6 This is a second schematic diagram of the structure of a pre-charge module according to an embodiment of this application;

[0027] Figure 7This is the third schematic diagram of the pre-charge module according to an embodiment of this application;

[0028] Figure 8 This is the fourth schematic diagram of the pre-charge module according to an embodiment of this application;

[0029] Figure 9 This is one of the structural schematic diagrams of a surge absorption module according to an embodiment of this application;

[0030] Figure 10 This is a second schematic diagram of the surge absorption module according to an embodiment of this application;

[0031] Figure 11 This is the third schematic diagram of the surge absorption module according to an embodiment of this application;

[0032] Figure 12a This is one of the structural schematic diagrams of a protection device for a DC-DC converter according to another embodiment of this application;

[0033] Figure 12b This is a second schematic diagram of the structure of a protection device for a DC-DC converter according to another embodiment of this application;

[0034] Figure 13a This is the third schematic diagram of the structure of the protection device of a DC-DC converter according to yet another embodiment of this application;

[0035] Figure 13b This is the fourth schematic diagram of the structure of the protection device of a DC-DC converter according to another embodiment of this application;

[0036] Figure 14 This is a schematic diagram of the structure of a connector according to an embodiment of this application;

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. Protective device; 2. Battery pack; 3. DC-DC converter;

[0039] Precharge module 10, surge absorption module 20;

[0040] Positive protection switch CPA+, negative protection switch CPA-, pre-charge circuit 11;

[0041] Pre-charge resistor Ry, first switch K1, second switch K2, control circuit 111;

[0042] Microcontroller unit (MCU), power supply circuit 1111;

[0043] First voltage divider resistor Rf1, second voltage divider resistor Rf2, energy storage capacitor Cc;

[0044] First absorption circuit 21, second absorption circuit 22;

[0045] The first varistor R1, the second varistor R2, the third varistor R3, and the discharge tube DG.

[0046] First Y capacitor C1, second Y capacitor C2, thermistor R4, differential mode inductor L1;

[0047] Common mode inductor L2, bleeder resistors R5, R6, R7, and absorption capacitor C3;

[0048] Safety module 30, connector 40, connection button 41, knob 42, nut 43. DETAILED DESCRIPTION

[0049] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0050] 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 pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0051] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0052] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0053] In the description of the embodiments of this application, the term "and / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0054] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0055] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0056] With the rapid development of new energy technologies, battery-powered new energy vehicles are becoming increasingly popular. In these vehicles, the DC-DC converter is a crucial component, converting the energy from a high-voltage DC battery into energy suitable for low-voltage DC appliances. For example, the voltage range of the power battery in a pure electric commercial vehicle is between 480V and 700V, while the voltage needed to power the electronic control unit, multimedia system, instrument panel, and lighting equipment needs to be reduced to 24V. Currently, surges occur during vehicle startup and relay closure, which can cause DC-DC converter failure, affecting the safety of the entire vehicle.

[0057] To address the aforementioned issues, this application provides a protection device for a DC-DC converter. This protection device includes a pre-charge module; the pre-charge module reduces the input voltage of the battery pack for a preset period after the DC-DC converter is connected to the battery pack via the protection device. In this application embodiment, the protection device can reduce the input voltage of the battery pack for a period of time after the DC-DC converter is connected to the battery pack, thereby reducing the risk of DC-DC converter failure due to high voltage and high current surges, and thus improving the safety of the entire vehicle.

[0058] The technical solutions involved in the embodiments of this application are described below.

[0059] According to some embodiments of this application, refer to Figure 1 A protection device for a DC-DC converter is provided. The protection device 1 includes a pre-charge module 10; the pre-charge module 10 is coupled to a battery pack 2 and a DC-DC converter 3 respectively; the pre-charge module 10 is used to reduce the input voltage of the battery pack 2 during a preset period after the DC-DC converter 3 is connected to the battery pack 2 through the protection device 1.

[0060] In this embodiment, the protective device 1 includes a pre-charge module 10. After the protective device 1 is connected to the battery pack 2 and the DC-DC converter 3 respectively, the input terminal of the pre-charge module 10 is connected to the battery pack 2, and the output terminal of the pre-charge module 10 is connected to the input terminal of the DC-DC converter 3.

[0061] During the initial period after the protection device 1 is connected to the battery pack 2, the voltage output by the battery pack 2 is transmitted to the protection device 1, where it is reduced by the pre-charge module 10. The reduced voltage is then transmitted to the DC-DC converter 3. In this way, even if the voltage output by the battery pack 2 is high, the voltage transmitted to the DC-DC converter 3 will not cause the DC-DC converter 3 to fail after the reduction processing by the pre-charge module 10.

[0062] In some embodiments, the protective device 1 can be connected to the battery pack 2 via a junction box. (See reference...) Figure 2 The positive and negative terminals of battery pack 2 are connected to the junction box, which in turn is connected to the protective device 1. It should be noted that the internal connections of the junction box can be configured according to actual conditions.

[0063] In some embodiments, the output of the DC-DC converter 3 can be connected to automotive accessories such as vehicle lights, vehicle controllers, and small electrical appliances to supply power to these devices.

[0064] In the above embodiments, the protection device for the DC-DC converter includes a pre-charge module; the pre-charge module reduces the input voltage of the battery pack within a preset period after the DC-DC converter is connected to the battery pack through the protection device. By employing the protection device provided in this application embodiment, the input voltage of the battery pack can be reduced for a period of time after the DC-DC converter is connected to the battery pack, reducing the risk of DC-DC converter failure due to high voltage and high current surges, thereby improving the safety of the entire vehicle.

[0065] According to some embodiments of this application, refer to Figure 3 The protection device 1 also includes a surge absorption module 20; the surge absorption module 20 is disposed between the battery pack 2 and the precharge module 10; the surge absorption module 20 is used to absorb differential mode surges and common mode surges input to the battery pack 2.

[0066] In this embodiment, the protection device 1 includes a pre-charge module 10 and a surge absorption module 20, with the output terminal of the surge absorption module 20 connected to the input terminal of the pre-charge module 10. After the protection device 1 is connected to the battery pack 2 and the DC-DC converter 3 respectively, the input terminal of the surge absorption module 20 is connected to the battery pack 2, and the output terminal of the pre-charge module 10 is connected to the DC-DC converter 3.

[0067] Throughout the connection between the DC converter and the battery pack, if a surge occurs in the battery pack 2, the surge is transmitted to the protection device 1, where it is absorbed by the surge absorption module 20. This can reduce the surge transmitted to the DC converter 3, or even prevent the surge from being transmitted to the DC converter 3. In this way, the risk of the DC converter 3 failing due to the surge can be reduced.

[0068] Furthermore, during the initial period after the protective device 1 is connected to the battery pack 2, the voltage output by the battery pack 2 is transmitted to the pre-charge module 10, where it is reduced. The reduced voltage is then transmitted to the DC-DC converter 3. In this way, even if the voltage output by the battery pack 2 is high, the voltage transmitted to the DC-DC converter 3 will not cause the DC-DC converter 3 to fail after the reduction processing by the pre-charge module 10.

[0069] In the above embodiments, the protection device for the DC-DC converter includes a pre-charge module and a surge absorption module. The surge absorption module absorbs differential-mode surges and common-mode surges input to the battery pack. The pre-charge module reduces the input voltage of the battery pack within a preset period after the DC-DC converter is connected to the battery pack through the protection device. Using the protection device provided in this application embodiment, the input voltage of the battery pack can be reduced for a period of time after the DC-DC converter is connected to the battery pack, and surges can be absorbed throughout the connection process between the DC-DC converter and the battery pack, thereby reducing the risk of DC-DC converter failure due to surges and improving the safety of the entire vehicle.

[0070] According to some embodiments of this application, refer to Figure 4 The protection device 1 also includes a surge absorption module 20; the surge absorption module 20 is disposed between the precharge module 10 and the DC converter 3; the surge absorption module 20 is used to absorb differential mode surges and common mode surges input to the battery pack 1.

[0071] In this embodiment, the protection device 1 includes a pre-charge module 10 and a surge absorption module 20, with the output terminal of the pre-charge module 10 connected to the input terminal of the surge absorption module 20. After the protection device 1 is connected to the battery pack 2 and the DC-DC converter 3 respectively, the input terminal of the pre-charge module 10 is connected to the battery pack 2, and the output terminal of the surge absorption module 20 is connected to the DC-DC converter 3.

[0072] For a short period after the protection device 1 is connected to the battery pack 2, the voltage output by the battery pack 2 is transmitted to the pre-charge module 10, where it is reduced. The reduced voltage is then transmitted to the DC-DC converter 3 through the surge absorption module 20. In this way, even if the voltage output by the battery pack 2 is high, the voltage transmitted to the DC-DC converter 3 will not cause the DC-DC converter 3 to fail after being reduced by the pre-charge module 10.

[0073] Throughout the connection between the DC converter and the battery pack, if a surge occurs in the battery pack 2, the surge is transmitted to the protection device 1, where it is absorbed by the surge absorption module 20. This can reduce the surge transmitted to the DC converter 3, or even prevent the surge from being transmitted to the DC converter 3. In this way, the risk of the DC converter 3 failing due to the surge can be reduced.

[0074] In the above embodiments, the protection device for the DC-DC converter includes a pre-charge module and a surge absorption module. The pre-charge module reduces the input voltage of the battery pack during a preset period after the DC-DC converter is connected to the battery pack via the protection device. The surge absorption module absorbs differential-mode surges and common-mode surges input to the battery pack. By employing the protection device provided in this application embodiment, the input voltage of the battery pack can be reduced for a period of time after the DC-DC converter is connected to the battery pack, and surges can be absorbed throughout the entire connection process between the DC-DC converter and the battery pack, thereby reducing the risk of DC-DC converter failure due to surges and improving the safety of the entire vehicle.

[0075] According to some embodiments of this application, refer to Figure 5 The precharge module 10 includes a positive protection switch CPA+, a negative protection switch CPA-, and a precharge circuit 11. The first terminal of the positive protection switch CPA+ is connected to the positive input terminal INPUT+ of the precharge module 10, and the second terminal of the positive protection switch CPA+ is connected to the first terminal of the precharge circuit 11. The second terminal of the precharge circuit 11 is connected to the positive output terminal of the precharge module 10. The first terminal of the negative protection switch CPA- is connected to the positive input terminal INPUT+ of the precharge module 10, and the second terminal of the negative protection switch CPA- is connected to the negative output terminal OUTPUT- of the precharge module 10. The positive protection switch CPA+ and the negative protection switch CPA- are used to close after the precharge module 10 is connected to the battery pack 2. The precharge circuit 11 is used to reduce the input voltage of the battery pack 2 during a preset period after the positive protection switch CPA+ is closed.

[0076] In this embodiment, when the surge absorption module 20 is positioned between the battery pack 2 and the precharge module 10, the positive terminal of the battery pack 2 is connected to the positive input terminal INPUT+ of the surge absorption module 20, and the negative terminal of the battery pack 2 is connected to the negative input terminal INPUT- of the surge absorption module 20; the positive output terminal OUTPUT+ of the surge absorption module 20 is connected to the positive input terminal INPUT+ of the precharge module 10, and the negative output terminal OUTPUT- of the surge absorption module 20 is connected to the negative input terminal INPUT- of the precharge module 10. The positive output terminal OUTPUT+ and the negative output terminal OUTPUT- of the precharge module 10 are respectively connected to the DC-DC converter 3.

[0077] With the surge absorption module 20 positioned between the precharge module 10 and the DC-DC converter 3, the positive terminal of the battery pack 2 is electrically connected to the positive input terminal INPUT+ of the precharge module 10, and the negative terminal of the battery pack 2 is electrically connected to the negative input terminal INPUT- of the precharge module 10. The positive output terminal OUTPUT+ of the precharge module 10 is connected to the positive input terminal INPUT+ of the surge absorption module 20, and the negative output terminal OUTPUT- of the precharge module 10 is connected to the negative input terminal INPUT- of the surge absorption module 20. The positive output terminal OUTPUT+ and the negative output terminal OUTPUT- of the surge absorption module 20 are respectively connected to the DC-DC converter 3.

[0078] The precharge module 10 includes a positive protection switch CPA+, a negative protection switch CPA-, and a precharge circuit 11. The two ends of the positive protection switch CPA+ are connected to the positive input terminal INPUT+ of the precharge module 10 and the first terminal of the precharge circuit 11, respectively. The two ends of the negative protection switch CPA- are connected to the negative input terminal INPUT- and the negative output terminal OUTPUT- of the precharge module 10, respectively.

[0079] After the precharge module 10 is electrically connected to the battery pack 2, the positive protection switch CPA+ and the negative protection switch CPA- close. The voltage output from the positive terminal of the battery pack 2 is transmitted to the precharge circuit 11 through the positive input terminal INPUT+ of the precharge module 10. The precharge circuit 11 reduces this voltage and outputs the reduced voltage from the positive output terminal OUTPUT+ of the precharge module 10. After a preset period of time, the precharge circuit 11 no longer reduces the voltage output from the positive terminal of the battery pack 2, but directly outputs the voltage from the positive output terminal OUTPUT+ of the precharge module 10.

[0080] The aforementioned positive protection switch CPA+ and negative protection switch CPA- can employ a connector position assurance (CPA) mechanism. For example, the connection wire of the junction box engages with and locks with the CPA of the precharge module 10. When the CPA is closed, the voltage output from the battery pack 2 can be transmitted through the junction box to the precharge circuit 11 of the precharge module 10.

[0081] It should be noted that the positive protection switch CPA+ and the negative protection switch CPA- are not limited to the examples above. In practical applications, other switches or other structures can be used.

[0082] In the above embodiments, the pre-charge module includes a positive protection switch, a negative protection switch, and a pre-charge circuit. This application embodiment employs a positive protection switch and a negative protection switch, which can protect operators and reduce safety hazards caused by surges generated at the moment the protection device is activated. The pre-charge circuit can reduce the input voltage of the battery pack for a preset period after the positive protection switch is closed, thereby reducing the voltage transmitted to the DC-DC converter during the initial connection period, protecting the DC-DC converter, and improving its safety.

[0083] According to some embodiments of this application, refer to Figure 6 The pre-charging circuit 11 includes a pre-charging resistor Ry, a first switch K1, a second switch K2, and a control circuit 111. The first end of the pre-charging resistor Ry is connected to the second end of the positive protection switch CPA+, and the second end of the pre-charging resistor Ry is connected to the first end of the first switch K1. The second end of the first switch K1 is connected to the control circuit 111 and the positive output terminal OUTPUT+ of the pre-charging module 10. The first end of the second switch K2 is connected to the second end of the positive protection switch CPA+, and the second end of the second switch K2 is connected to the positive output terminal OUTPUT+ of the pre-charging module 10. The control circuit 111 is connected to the first switch K1 and the second switch K2. The control circuit 111 is used to control the first switch K1 to open and the second switch K2 to close after detecting that the voltage of the pre-charging resistor Ry reaches a preset voltage.

[0084] In this embodiment, the pre-charging circuit 11 may include a pre-charging resistor Ry, a first switch K1, a second switch K2, and a control circuit 111. The two ends of the pre-charging resistor Ry are connected to the positive protection switch CPA+ and the first switch K1, respectively. The first switch K1 is also connected to the positive output terminal OUTPUT+ of the pre-charging module 10. The two ends of the second switch K2 are connected to the positive protection switch CPA+ and the positive output terminal OUTPUT+ of the pre-charging module 10, respectively.

[0085] The first switch K1 can be a normally closed switch. After the positive protection switch CPA+ is closed, the voltage output from the positive terminal of the battery pack 2 is output from the positive output terminal OUTPUT+ of the precharge module 10 through the positive protection switch CPA+, the precharge resistor Ry, and the first switch K1.

[0086] The control circuit 111 is electrically connected to the first switch K1 and communicatively connected to both the first switch K1 and the second switch K2. The voltage input to the battery pack 2 is transmitted to the control circuit 111 via the first switch K1, supplying power to the control circuit 111. Upon receiving the supply voltage, the control circuit 111 begins operation, detecting whether the voltage of the pre-charge resistor Ry reaches a preset voltage. If the voltage of the pre-charge resistor Ry reaches the preset voltage, it controls the first switch K1 to open and the second switch K2 to close. This allows the voltage input to the battery pack 2 to be output from the positive output terminal OUTPUT+ of the pre-charge module 10 through the positive protection switch CPA+ and the second switch K2.

[0087] In some embodiments, a voltage sensor is provided at the pre-charge resistor Ry, which is connected to the control circuit 111. The control circuit 111 can detect whether the voltage of the pre-charge resistor Ry has reached a preset voltage based on the voltage collected by the voltage sensor.

[0088] In some embodiments, a current sensor is provided at the pre-charging resistor Ry, which is connected to the control circuit 111. The control circuit 111 can detect whether the voltage of the pre-charging resistor Ry reaches a preset voltage based on the current collected by the current sensor and the resistance value of the pre-charging resistor Ry.

[0089] Taking the output voltage of battery pack 2 as 700V as an example, the preset voltage can be set to 700V. When the control circuit 111 detects that the voltage of the pre-charge resistor Ry reaches 700V, it controls the first switch K1 to open and the second switch K2 to close, so that the voltage input to battery pack 2 can be output from the positive output terminal OUTPUT+ of the pre-charge module 10 through the positive protection switch CPA+ and the second switch K2.

[0090] In the above embodiments, the pre-charging circuit includes a pre-charging resistor, a first switch, a second switch, and a control circuit. This embodiment detects whether the voltage of the pre-charging resistor reaches a preset voltage. If the voltage of the pre-charging resistor does not reach the preset voltage, the first switch closes and the second switch opens, resulting in a reduced voltage output from the pre-charging module. If the voltage of the pre-charging resistor reaches the preset voltage, the control circuit controls the first switch to open and the second switch to close, allowing the battery pack input voltage to be directly output from the pre-charging module output terminal. The pre-charging circuit has a simple structure, its control logic is easy to implement, and it can reduce the voltage transmitted to the DC-DC converter during the initial connection period, thereby protecting the DC-DC converter and improving its safety.

[0091] According to some embodiments of this application, refer to Figure 7The control circuit 111 includes a microcontroller unit (MCU) and a power supply circuit 1111. The power supply circuit 1111 is connected to the first switch K1, the microcontroller unit (MCU), and the positive output terminal OUT+ of the precharge module 10. The microcontroller unit (MCU) is also connected to the first switch K1 and the second switch K2. The power supply circuit 1111 is used to supply power to the microcontroller unit (MCU) after the positive protection switch CPA+ is closed. The microcontroller unit (MCU) is used to control the first switch K1 to open and the second switch K2 to close after detecting that the voltage of the precharge resistor Ry has reached a preset voltage.

[0092] In this embodiment of the application, the control circuit 111 may include a microcontroller unit (MCU) and a power supply circuit 1111. The power supply circuit 1111 outputs to the first switch K1, the microcontroller unit (MCU), and the positive output terminal OUTPUT+ of the precharge module 10.

[0093] After the positive protection switch CPA+ is closed, the voltage input to the battery pack 2 is transmitted to the power supply circuit 1111 through the positive protection switch CPA+, the pre-charge resistor Ry, and the first switch K1. The power supply circuit 1111 provides the power supply voltage to the microcontroller unit MCU based on this voltage, so that the microcontroller unit MCU starts to work.

[0094] The microcontroller unit (MCU) is communicatively connected to the first switch K1 and the second switch K2. After the MCU starts working, it detects whether the voltage of the pre-charge resistor Ry has reached the preset voltage. If the voltage of the pre-charge resistor Ry has not reached the preset voltage, the MCU does not perform any control. If the voltage of the pre-charge resistor Ry has reached the preset voltage, the MCU controls the first switch K1 to open and the second switch K2 to close.

[0095] In the above embodiments, the control circuit includes a microcontroller unit and a power supply circuit. This application embodiment uses a microcontroller unit for control, resulting in a simple control circuit structure, easily implemented control logic, and the ability to reduce the voltage transmitted to the DC-DC converter during the initial connection period, thereby protecting the DC-DC converter.

[0096] According to some embodiments of this application, refer to Figure 8 The power supply circuit 1111 includes a first voltage divider resistor Rf1, a second voltage divider resistor Rf2, and an energy storage capacitor Cc; the first end of the first voltage divider resistor Rf1 is connected to the second end of the first switch K1, the second end of the first voltage divider resistor Rf1 is connected to the first end of the second voltage divider resistor Rf2, and the second end of the second voltage divider resistor Rf2 is grounded to GND; the common end of the first voltage divider resistor Rf1 and the second voltage divider resistor Rf2 is connected to the microcontroller unit MCU and the first end of the energy storage capacitor Cc, respectively, and the second end of the energy storage capacitor Cc is grounded to GND.

[0097] In this embodiment of the application, the power supply circuit 1111 includes a first voltage divider resistor Rf1 and a second voltage divider resistor Rf2. The first voltage divider resistor Rf1 and the second voltage divider resistor Rf2 are connected in series. One end of the series circuit is connected to the first switch K1 and the positive output terminal OUTPUT+ of the precharge module 10, respectively, and the other end is grounded to GND.

[0098] After the positive protection switch CPA+ is closed, the voltage input to battery pack 2 is transmitted through the positive protection switch CPA+, the pre-charge resistor Ry, and the first switch K1 to the first voltage divider resistor Rf1 and the second voltage divider resistor Rf2. The microcontroller unit (MCU) is connected to the common terminal of the first voltage divider resistor Rf1 and the second voltage divider resistor Rf2, and the voltage applied across the second voltage divider resistor Rf2 is the power supply voltage for the MCU.

[0099] When the voltage input to battery pack 2 is transmitted to the first voltage divider resistor Rf1 and the second voltage divider resistor Rf2, it charges the energy storage capacitor Cc. After the microcontroller unit (MCU) controls the first switch K1 to open and the second switch K2 to close, the energy storage capacitor Cc supplies power to the MCU.

[0100] In the above embodiments, the power supply circuit includes a first voltage divider resistor, a second voltage divider resistor, and an energy storage capacitor. In this embodiment, the first and second voltage divider resistors are used to power the microcontroller unit during the pre-charging stage, and the energy storage capacitor is used in subsequent stages. The power supply circuit is easy to implement and relatively stable, enabling the microcontroller unit to operate stably, thereby ensuring the stable operation of the protection device.

[0101] According to some embodiments of this application, refer to Figure 9 The surge absorption module 20 includes a first absorption circuit 21 and a second absorption circuit 22 connected to each other. The input terminal of the first absorption circuit 21 is connected to the input terminal of the surge absorption module 20, and the output terminal of the second absorption circuit 22 is connected to the output terminal of the surge absorption module 20. The first absorption circuit 21 is used to absorb differential-mode surges and common-mode surges. The second absorption circuit 22 is used to absorb differential-mode surges and common-mode surges again.

[0102] In this embodiment, when the surge absorption module 20 is disposed between the battery pack 2 and the precharge module 10, the positive terminal of the battery pack 2 is connected to the positive input terminal INPUT+ of the surge absorption module 20, and the negative terminal of the battery pack 2 is connected to the negative input terminal INPUT- of the surge absorption module 20; the positive output terminal OUTPUT+ of the surge absorption module 20 is connected to the positive input terminal INPUT+ of the precharge module 10, and the negative output terminal OUTPUT- of the surge absorption module 20 is connected to the negative input terminal INPUT- of the precharge module 10.

[0103] When the surge absorption module 20 is positioned between the precharge module 10 and the DC-DC converter 3, the positive input terminal INPUT+ of the surge absorption module 20 is connected to the positive output terminal OUTPUT+ of the precharge module 10, and the negative input terminal INPUT- of the surge absorption module 20 is connected to the negative output terminal OUTPUT- of the precharge module 10; the positive output terminal OUTPUT+ of the surge absorption module 20 is connected to the positive input terminal of the DC-DC converter 3, and the negative output terminal OUTPUT- of the surge absorption module 20 is connected to the negative input terminal of the DC-DC converter 3.

[0104] The surge absorption module 20 includes a first absorption circuit 21 and a second absorption circuit 22. The positive input terminal of the first absorption circuit 21 is connected to the positive input terminal INPUT+ of the surge absorption module 20, and the negative input terminal of the first absorption circuit 21 is connected to the negative input terminal INPUT- of the surge absorption module 20. The positive output terminal of the first absorption circuit 21 is connected to the positive input terminal of the second absorption circuit 22, and the negative output terminal of the first absorption circuit 21 is connected to the negative input terminal of the second absorption module. The positive output terminal of the second absorption circuit 22 is connected to the positive output terminal OUTPUT+ of the surge absorption module 20, and the negative output terminal of the second absorption circuit 22 is connected to the negative output terminal OUTPUT- of the surge absorption module 20.

[0105] After the surge generated by the battery pack 2 is input to the protection device 1, it is first absorbed by the first absorption circuit 21 of the surge absorption module 20, and then second absorbed by the second absorption circuit 22 of the surge absorption module 20.

[0106] In some embodiments, the surge generated by the battery pack 2 includes differential mode surge and common mode surge, and both the first absorption circuit 21 and the second absorption circuit 22 can absorb differential mode surge and common mode surge.

[0107] In the above embodiments, the surge absorption module includes a first absorption circuit and a second absorption circuit connected to each other. This application embodiment uses a first absorption circuit and a second absorption circuit to perform two-stage absorption of surges input to the battery pack, which can absorb more surges, thereby reducing the risk of DC-DC converter failure due to surges.

[0108] According to some embodiments of this application, refer to Figure 10The first absorption circuit 21 includes a first varistor R1, a second varistor R2, a third varistor R3, and a discharge tube DG. The two ends of the first varistor R1 are connected to the positive input terminal INPUT+ and the negative input terminal INPUT- of the surge absorption module 20, respectively. The first end of the second varistor R2 is connected to the positive input terminal INPUT+ of the surge absorption module 20, and the second end of the second varistor R2 is connected to the first end of the third varistor R3. The second end of the third varistor R3 is connected to the negative input terminal INPUT- of the surge absorption module 20. The first end of the discharge tube DG is connected to the common terminal of the second varistor R2 and the third varistor R3, and the second end of the discharge tube DG is grounded to GND.

[0109] In this embodiment, the first absorption circuit 21 includes a first varistor R1, a second varistor R2, a third varistor R3, and a discharge tube DG. The two ends of the first varistor R1 are connected to the positive input terminal INPUT+ and the negative input terminal INPUT- of the surge absorption module 20, respectively. The second varistor R2 and the third varistor R3 are connected in series, with the two ends of the series circuit connected to the positive input terminal INPUT+ and the negative input terminal INPUT- of the surge absorption module 20, respectively. The first end of the discharge tube DG is connected to the common terminal of the second varistor R2 and the third varistor R3, and the second end of the discharge tube DG is grounded to GND.

[0110] When a differential-mode surge is input, the resistance of the first varistor R1 changes, suppressing the voltage within a preset range. Subsequent circuitry then absorbs the remaining differential-mode surge. When a common-mode surge is input, the resistances of the second and third varistors R2 and R3 change, suppressing the voltage. The discharge transistor DG then discharges the surge, and subsequent circuitry absorbs the remaining common-mode surge.

[0111] The resistance of the aforementioned varistor is related to the magnitude of the voltage applied across its terminals. When the voltage applied to the varistor is within its nominal value, the resistance is infinite, and almost no current flows. When the voltage across the varistor is slightly higher than the nominal voltage, the varistor quickly breaks down and conducts, its resistance drops rapidly, and the resistor is in a conducting state. When the voltage decreases below the nominal voltage, its resistance begins to increase again, and the varistor returns to a high-resistance state.

[0112] The preset voltage range is determined based on the input voltage of the DC-DC converter 3. For example, if the DC-DC converter 3 converts the input 700V to the output 24V, then the preset voltage range is 700V.

[0113] In the above embodiments, the first absorption circuit includes a first varistor, a second varistor, a third varistor, and a discharge tube. This application embodiment uses a first varistor to absorb differential-mode surges and uses a second varistor, a third varistor, and a discharge tube to absorb common-mode surges. This can comprehensively and fully absorb surges input from the battery pack, reducing the risk of DC-DC converter failure due to surges.

[0114] According to some embodiments of this application, refer to Figure 11 The second absorption circuit 22 includes a first Y capacitor C1, a second Y capacitor C2, a thermistor R4, a differential-mode inductor L1, a common-mode inductor L2, multiple bleeder resistors R5, R6, and R7, and an absorption capacitor C3. The first terminal of the first Y capacitor C1 is connected to the positive input terminal INPUT+ of the surge absorption module 20, and the second terminal of the first Y capacitor C1 is connected to the first terminal of the second Y capacitor C2. The common terminal of the first Y capacitor C1 and the second Y capacitor C2 is grounded to GND. The second terminal of the second Y capacitor C2 is connected to the negative input terminal INPUT- of the surge absorption module 20. The first terminal of the thermistor R4 is connected to the positive input terminal INPUT+ of the surge absorption module 20, and the second terminal of the thermistor R4 is connected to the first terminal of the differential-mode inductor L1. One end is connected; the second end of the differential mode inductor L1 is connected to the first end of the common mode inductor L2; the second end of the common mode inductor L2 is connected to the negative input terminal INPUT- of the surge absorption module 20, the third end of the common mode inductor L2 is connected to the positive output terminal OUTPUT+ of the surge absorption module 20, and the fourth end of the common mode inductor L2 is connected to the negative output terminal OUTPUT- of the surge absorption module 20; multiple bleeder resistors R5, R6, and R7 are connected in series, and the two ends of the series circuit are respectively connected to the positive output terminal OUTPUT+ and the negative output terminal OUTPUT- of the surge absorption module 20; the two ends of the absorption capacitor C3 are respectively connected to the positive output terminal OUTPUT+ and the negative output terminal OUTPUT- of the surge absorption module 20.

[0115] In this embodiment of the application, the second absorption circuit 22 includes a first Y capacitor C1, a second Y capacitor C2, a thermistor R4, a differential mode inductor L1, a common mode inductor L2, multiple bleeder resistors R5, R6, R7, and an absorption capacitor C3.

[0116] The first Y capacitor C1 and the second Y capacitor C2 are connected in series. The two ends of the series circuit are connected to the positive input terminal INPUT+ and the negative input terminal INPUT- of the surge absorption module 20, respectively. The two ends of the thermistor R4 are connected to the positive input terminal INPUT+ of the surge absorption module 20 and the differential mode inductor L1, respectively.

[0117] The first terminal of the common-mode inductor L2 is connected to the differential-mode inductor L1; the second terminal of the common-mode inductor L2 is connected to the negative input terminal INPUT- of the surge absorption module 20; the third terminal of the common-mode inductor L2 is connected to the positive output terminal OUTPUT+ of the surge absorption module 20; and the fourth terminal of the common-mode inductor L2 is connected to the negative output terminal OUTPUT- of the surge absorption module 20.

[0118] Multiple bleeder resistors R5, R6, and R7 are connected in series, with their two ends connected to the positive output terminal OUTPUT+ and the negative output terminal OUTPUT- of the surge absorption module 20, respectively. The two ends of the absorption capacitor C3 are also connected to the positive output terminal OUTPUT+ and the negative output terminal OUTPUT- of the surge absorption module 20, respectively. It should be noted that the number and value of the bleeder resistors can be set according to actual conditions.

[0119] The principles of surge absorption can include: capacitors absorb part of the surge energy, reduce the voltage amplitude, and protect other circuits in the circuit; inductors utilize their characteristics to generate a reverse electromotive force when the current changes abruptly, slowing down the rate of change of the current, thereby reducing the surge voltage.

[0120] The aforementioned thermistor R4, differential-mode inductor L1, absorption capacitor C3, and bleeder resistor are used to absorb differential-mode surges. The differential-mode inductor L1 and absorption capacitor C3 (X capacitor) form a circuit. Because the differential-mode inductor L1 has a high inductive reactance to differential-mode surges, while the absorption capacitor C3 has a low capacitive reactance, they can filter out differential-mode surges, thus suppressing them. Resistors R5, R6, and R7 form a bleeder circuit, enabling rapid voltage release.

[0121] The aforementioned first Y capacitor C1, second Y capacitor C2, and common-mode inductor L2 are used to absorb common-mode surges. When a common-mode surge passes through common-mode inductor L2, a magnetic field of the same direction is generated within common-mode inductor L2. This increases the inductance of common-mode inductor L2, which in turn increases its inductive reactance to the common-mode surge, thus suppressing the surge more effectively and achieving the purpose of attenuating it. Simultaneously, the energy absorption of Y capacitors C1 and C2 also suppresses the common-mode surge, resulting in even more significant suppression.

[0122] In the above embodiments, the second absorption circuit includes a first Y capacitor, a second Y capacitor, a thermistor, a differential-mode inductor, a common-mode inductor, multiple bleeder resistors, and an absorption capacitor. This embodiment, based on the surge absorption already performed by the first absorption circuit, further employs a thermistor, differential-mode inductor, absorption capacitor, and bleeder resistor to absorb differential-mode surges, and a first Y capacitor, second Y capacitor, and common-mode inductor to absorb common-mode surges. This further suppresses both differential-mode and common-mode surges, significantly reducing the risk of DC-DC converter failure due to surges and providing more robust protection for the DC-DC converter.

[0123] According to some embodiments of this application, refer to Figure 12a and 12b The protective device 1 also includes a fuse module 30; the input terminal of the fuse module 30 is connected to the battery pack 2, and the output terminal of the fuse module 30 is connected to the input terminal of the precharge module 10; the fuse module 30 is used to melt and disconnect the battery pack 2 from the DC-DC converter 3 when the voltage input to the battery pack 2 exceeds a preset voltage threshold.

[0124] In this embodiment of the application, the protective device 1 may further include a safety module 30, such as... Figure 12a The insurance module 30, surge absorption module 20, and pre-charge module 10 are connected in sequence; for example... Figure 12b The fuse module 30, precharge module 10, and surge absorption module 20 are connected in sequence. After the protection device 1 is connected to the battery pack 2 and the DC-DC converter 3, the input terminal of the fuse module 30 can be connected to the battery pack 2 through the junction box.

[0125] The safety module 30 can be equipped with devices such as fuses. When the input voltage of the battery pack 2 exceeds a preset voltage threshold, the fuse blows, cutting off the path between the battery pack 2 and the DC-DC converter 3.

[0126] In the above embodiments, the protective device further includes a fuse module; the fuse module melts when the voltage input to the battery pack exceeds a preset voltage threshold, cutting off the path between the battery pack and the DC-DC converter. In this embodiment, when the protective device is assembled with the battery pack or junction box, a large current or voltage surge may occur; the fuse module can improve the safety of the assembly process.

[0127] According to some embodiments of this application, refer to Figure 13a and 13b The insurance module 30, the precharge module 10 and the surge absorption module 20 are assembled and connected by the connector 40.

[0128] In this embodiment, the connection between the safety module 30, the pre-charge module 10, and the surge absorption module 20 can be achieved through assembly using the connector 40. This connection method simplifies assembly and disassembly, allows for flexible combination of multiple modules, and enables module expansion based on this method. This allows the protective device to meet the needs of various products and expands its application scenarios.

[0129] According to some embodiments of this application, refer to Figure 14 The insurance module 30, the precharge module 10 and the surge absorption module 20 all include a module housing, and the connector 40 includes a connection button 41, a knob 42 and a nut 43; the connection button 41 and the knob 42 are located on the first side of the module housing, and the nut 43 is located on the second side of the module housing.

[0130] In this embodiment, the safety module 30, precharge module 10, and surge absorption module 20 all include a module housing, and a connector 40 is disposed on the module housing. Exemplarily, the module housing of the safety module 30 has a connection button 41 and a knob 42 on a first side, and a nut 43 on a second side; the module housing of the precharge module 10 also has a connection button 41 and a knob 42 on a first side, and a nut 43 on a second side; the module housing of the surge absorption module 20 also has a connection button 41 and a knob 42 on a first side, and a nut 43 on a second side. Thus, the nut 43 of the safety module 30 engages with the knob 42 of the precharge module 10, triggering the connection button 41 of the precharge module 10; the nut 43 of the precharge module 10 engages with the knob 42 of the surge absorption module 20, triggering the connection button 41 of the surge absorption module 20.

[0131] It should be noted that the first side and the second side can be two opposite sides or two adjacent sides. The structure and connection relationship of the connector 40 are not limited to the above example and can be set according to the actual situation.

[0132] In some embodiments, the module housing is provided with two knobs 42 and two nuts 43. The two knobs 42 are connected inside the module housing to the positive input terminal INPUT+ and the negative input terminal INPUT-, respectively. The two nuts 43 are connected inside the module housing to the positive output terminal OUTPUT+ and the negative output terminal OUTPUT-, respectively. Alternatively, the two knobs 42 are connected inside the module housing to the positive output terminal OUTPUT+ and the negative output terminal OUTPUT-, respectively. The two nuts 43 are also connected inside the module housing to the positive output terminal OUTPUT+ and the negative output terminal OUTPUT-, respectively.

[0133] The aforementioned connection button 41 can adopt a CPA structure. The CPA structure can reduce the energy consumption of the protective device 1 and can also greatly protect the operator, reducing the safety hazards caused by the surge generated when the protective device 1 is activated.

[0134] In some embodiments, the assembly point of nut 43 and knob 42 is insulated, for example, by providing an insulating sleeve or spraying insulating paint on the outside of nut 43. It should be noted that the insulation design method is not limited to the above example and can be set according to the actual situation.

[0135] In the above embodiments, the insurance module, pre-charge module, and surge absorption module all include a module housing, and the connectors include a connection button, a knob, and a nut; the connection button and knob are located on the first side of the module housing, and the nut is located on the second side of the module housing. This embodiment uses a knob and nut for connection, which facilitates assembly, disassembly, and replacement.

[0136] According to some embodiments of this application, the protective device 1 further includes a device housing and a heat sink; the safety module 30, the precharge module 10 and the surge absorption module 20 are disposed in the device housing, and the heat sink is disposed on the outer surface of the device housing.

[0137] In this embodiment of the application, the protective device 1 may further include a device housing, in which the safety module 30, the precharge module 10 and the surge absorption module 20, assembled with connector 40, are disposed.

[0138] The protective device 1 may also include a heat sink, with the heat sink disposed on the outer surface of the device housing. The heat sink may have a finned or similar structure.

[0139] In some embodiments, the device housing may also be coated with an insulator to protect the protective device 1.

[0140] In the above embodiments, the protective device further includes a device housing and a heat sink. This application embodiment uses a device housing to protect multiple internal modules, and uses a heat sink to improve the heat dissipation performance of the protective device, thereby enhancing its safety.

[0141] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0142] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. A protection device for a DC-DC converter, characterized in that, The protective device includes a pre-charge module, which is coupled to the battery pack and the DC-DC converter respectively; The pre-charge module is used to reduce the input voltage of the battery pack during a preset period after the DC converter is connected to the battery pack through the protection device.

2. The protective device according to claim 1, characterized in that, The protection device also includes a surge absorption module; the surge absorption module is disposed between the battery pack and the precharge module; The surge absorption module is used to absorb differential-mode surges and common-mode surges input from the battery pack.

3. The protective device according to claim 1, characterized in that, The protection device also includes a surge absorption module; the surge absorption module is disposed between the precharge module and the DC-DC converter; The surge absorption module is used to absorb differential-mode surges and common-mode surges input from the battery pack.

4. The protective device according to any one of claims 1-3, characterized in that, The pre-charge module includes a positive protection switch, a negative protection switch, and a pre-charge circuit; The first terminal of the positive protection switch is connected to the positive input terminal of the precharge module, and the second terminal of the positive protection switch is connected to the first terminal of the precharge circuit. The second end of the pre-charging circuit is connected to the positive output end of the pre-charging module; The first end of the negative protection switch is connected to the positive input end of the precharge module, and the second end of the negative protection switch is connected to the negative output end of the precharge module. The positive protection switch and the negative protection switch are used to close after the precharge module is connected to the battery pack; The pre-charging circuit is used to reduce the input voltage of the battery pack during a preset period after the positive protection switch is closed.

5. The protective device according to claim 4, characterized in that, The pre-charging circuit includes a pre-charging resistor, a first switch, a second switch, and a control circuit. The first end of the pre-charge resistor is connected to the second end of the positive protection switch, and the second end of the pre-charge resistor is connected to the first end of the first switch. The second terminal of the first switch is connected to both the control circuit and the positive output terminal of the precharge module. The first end of the second switch is connected to the second end of the positive protection switch, and the second end of the second switch is connected to the positive output end of the precharge module; The control circuit is connected to the first switch and the second switch respectively; The control circuit is used to control the first switch to open and the second switch to close after detecting that the voltage of the pre-charge resistor has reached a preset voltage.

6. The protective device according to claim 5, characterized in that, The control circuit includes a microcontroller unit and a power supply circuit; the power supply circuit is connected to the positive output terminal of the first switch, the microcontroller unit, and the precharge module, respectively; the microcontroller unit is also connected to the first switch and the second switch, respectively. The power supply circuit is used to supply power to the microcontroller unit after the positive protection switch is closed; The microcontroller unit is used to control the first switch to open and the second switch to close after detecting that the voltage of the pre-charge resistor has reached the preset voltage.

7. The protective device according to claim 6, characterized in that, The power supply circuit includes a first voltage divider resistor, a second voltage divider resistor, and an energy storage capacitor; The first end of the first voltage divider resistor is connected to the second end of the first switch, the second end of the first voltage divider resistor is connected to the first end of the second voltage divider resistor, and the second end of the second voltage divider resistor is grounded. The common terminal of the first voltage divider resistor and the second voltage divider resistor is connected to the first terminal of the microcontroller unit and the first terminal of the energy storage capacitor, respectively, and the second terminal of the energy storage capacitor is grounded.

8. The protective device according to claim 2 or 3, characterized in that, The surge absorption module includes a first absorption circuit and a second absorption circuit that are connected to each other. The input terminal of the first absorption circuit is connected to the input terminal of the surge absorption module, and the output terminal of the second absorption circuit is connected to the output terminal of the surge absorption module. The first absorption circuit is used to absorb the differential-mode surge and the common-mode surge; The second absorption circuit is used to absorb differential-mode surges and common-mode surges again.

9. The protective device according to claim 8, characterized in that, The first absorption circuit includes a first varistor, a second varistor, a third varistor, and a discharge tube; The two ends of the first varistor are respectively connected to the positive input terminal and the negative input terminal of the surge absorption module; The first end of the second varistor is connected to the positive input terminal of the surge absorption module, and the second end of the second varistor is connected to the first end of the third varistor. The second terminal of the third varistor is connected to the negative input terminal of the surge absorption module; The first end of the discharge tube is connected to the common terminal of the second and third varistors, and the second end of the discharge tube is grounded.

10. The protective device according to claim 8, characterized in that, The second absorption circuit includes a first Y capacitor, a second Y capacitor, a thermistor, a differential mode inductor, a common mode inductor, multiple bleeder resistors, and an absorption capacitor; The first terminal of the first Y capacitor is connected to the positive input terminal of the surge absorption module, the second terminal of the first Y capacitor is connected to the first terminal of the second Y capacitor, and the common terminal of the first Y capacitor and the second Y capacitor is grounded. The second terminal of the second Y capacitor is connected to the negative input terminal of the surge absorption module; The first end of the thermistor is connected to the positive input terminal of the surge absorption module, and the second end of the thermistor is connected to the first end of the differential mode inductor. The second terminal of the differential mode inductor is connected to the first terminal of the common mode inductor; The second terminal of the common mode inductor is connected to the negative input terminal of the surge absorption module, the third terminal of the common mode inductor is connected to the positive output terminal of the surge absorption module, and the fourth terminal of the common mode inductor is connected to the negative output terminal of the surge absorption module. The plurality of bleeder resistors are connected in series to form a series circuit, and the two ends of the series circuit are respectively connected to the positive output terminal and the negative output terminal of the surge absorption module. The two ends of the absorption capacitor are connected to the positive output terminal and the negative output terminal of the surge absorption module, respectively.

11. The protective device according to claim 2 or 3, characterized in that, The protective device also includes a safety module; the input terminal of the safety module is connected to the battery pack, and the output terminal of the safety module is connected to the input terminal of the precharge module or the surge absorption module. The fuse module is used to blow the circuit when the voltage input to the battery pack exceeds a preset voltage threshold, thereby cutting off the connection between the battery pack and the DC-DC converter.

12. The protective device according to claim 11, characterized in that, The insurance module, the pre-charge module, and the surge absorption module are assembled and connected by connectors.

13. The protective device according to claim 12, characterized in that, The insurance module, the precharge module, and the surge absorption module all include a module housing, and the connector includes a connection button, a knob, and a nut; The connection button and the knob are located on the first side of the module housing, and the nut is located on the second side of the module housing.

14. The protective device according to claim 11, characterized in that, The protective device also includes a housing and heat sinks; The insurance module, the precharge module, and the surge absorption module are disposed in the device housing, and the heat sink is disposed on the outer surface of the device housing.

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