A power battery pre-charging circuit, a power battery and a battery pack

Abstract

This utility model provides a pre-charging circuit for a power battery, belonging to the field of battery charging and discharging technology. It includes: a battery pack and a charging pre-charge relay and a discharging pre-charge relay electrically connected to the positive terminal of the battery pack; a main negative relay, one end of which is connected to the negative terminal of the battery pack, and the other end of which is connected to a discharging module and a charging module respectively; the charging pre-charge relay and the discharging pre-charge relay share the same pre-charging resistor, which is connected to the charging module and the discharging module respectively. Beneficial effects: By sharing the same pre-charging resistor, the pre-charging function of the charging and discharging circuit is achieved, while the shared resistor reduces the number of components and high-voltage wiring harnesses, thereby reducing the overall cost and improving product cost-effectiveness; at the same time, the reduction in the number of components and high-voltage wiring harnesses reduces the difficulty of layout, making it particularly suitable for areas with limited space.

Description

Technical Field

[0001] This utility model relates to the field of battery charging and discharging technology, and in particular to a power battery pre-charging circuit, a power battery, and a battery pack. Background Technology

[0002] With increasing global attention to environmental protection and sustainable development, new energy vehicles, as a green and efficient mode of transportation, are gradually becoming the mainstream of the automotive industry. In the power system of new energy vehicles, the vehicle's power is mainly provided by the electric motor, which in turn relies on a motor controller to achieve smooth operation.

[0003] Capacitors are one of the important components of motor controllers. When the vehicle is powered on, due to the presence of capacitors, if the main positive relay and the main negative relay are closed directly, the capacitors will be equivalent to a short circuit in an instant, which will cause a large current to appear in the entire high-voltage circuit. This large current surge can easily damage some equipment in the high-voltage circuit, such as relay contact erosion, fuse blowing, etc., affecting the normal operation of the vehicle and even creating safety hazards.

[0004] To solve the above problems, it is usually necessary to add a relay and a pre-charging resistor to form a pre-charging circuit. When the vehicle is powered on, the pre-charging circuit works first, gradually charging the capacitor. When the voltage across the capacitor approaches the power supply voltage, the main positive and main negative relays are then closed, thus ensuring the safety of the vehicle's power-on.

[0005] As a core component of the high-voltage system of power batteries, the pre-charging circuit plays an irreplaceable and crucial role in ensuring the safe and stable operation of the battery system, extending battery life, and improving user experience. With the rapid development and continuous innovation of new energy vehicle technology, the market has placed higher demands on the driving range, safety, and cost of new energy vehicles, making the design optimization and technological innovation of pre-charging circuits an increasingly important focus within the industry.

[0006] Currently, traditional solutions include pre-charging circuits in both the charging and discharging circuits, requiring two pre-charging resistors to complete the pre-charging process. However, as the capacity of power batteries continues to increase, the space for arranging electrical components within the battery pack is becoming increasingly limited, posing significant challenges to component placement. Furthermore, traditional solutions increase the cost of power batteries, thereby impacting their price competitiveness. Utility Model Content

[0007] To solve the above technical problems, this utility model provides a pre-charging circuit for a power battery; on the other hand, it also provides a power battery; and in another aspect, it also provides a battery pack.

[0008] The technical problem solved by this utility model can be achieved by the following technical solution:

[0009] A power battery pre-charging circuit includes:

[0010] The battery pack, and a pre-charge relay and a pre-charge relay electrically connected to the positive terminal of the battery pack;

[0011] A main negative relay, one end of which is connected to the negative terminal of the battery pack, and the other end of which is connected to the discharge module and the charging module respectively;

[0012] The charging pre-charge relay and the discharging pre-charge relay share the same pre-charge resistor, which is connected to the charging module and the discharging module, respectively.

[0013] Preferably, a shunt is provided between the main negative relay and the negative terminal of the battery pack.

[0014] Preferably, the pre-charge resistor includes a first end and a second end, the first end being connected to the pre-charge relay and the discharge module respectively, and the second end being connected to the pre-charge relay and the charging module respectively;

[0015] During discharge, the discharge pre-charge relay and the main negative relay are closed, and the current flows from the positive terminal of the battery pack through the discharge pre-charge relay, the second end of the pre-charge resistor, and the first end of the pre-charge resistor to the discharge module, pre-charging the discharge module.

[0016] During charging, the pre-charge relay and the main negative relay are closed, and the current flows from the positive terminal of the battery pack through the pre-charge relay, the first end of the pre-charge resistor, and the second end of the pre-charge resistor to the charging module to pre-charge the charging module.

[0017] Preferably, it further includes: a main positive relay, connected between the positive terminal of the battery pack and the discharge module.

[0018] Preferably, after the discharge module is pre-charged, the main positive relay closes and the discharge pre-charge relay opens to switch to the discharge circuit.

[0019] Preferably, it further includes: a fast charging relay, connected between the positive terminal of the battery pack and the charging module.

[0020] Preferably, after the charging module has finished pre-charging, the fast charging relay closes and the pre-charging relay opens to switch to the charging circuit.

[0021] On the other hand, a power battery is provided, the power battery including the power battery pre-charging circuit as described above.

[0022] In another aspect, a battery pack is provided, the battery pack comprising the power battery as described above.

[0023] The advantages or beneficial effects of this utility model's technical solution are as follows:

[0024] This invention uses a shared pre-charge resistor between the charging pre-charge relay and the discharging pre-charge relay. While realizing the pre-charge function of the charging and discharging circuit, the shared resistor can reduce the number of components and the number of high-voltage wiring harnesses used, thereby reducing the overall package cost and improving product cost-effectiveness. At the same time, the reduction in the number of components and high-voltage wiring harnesses reduces the difficulty of layout, making it particularly suitable for layout in areas with limited space. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the pre-charging circuit of the power battery in a preferred embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the charging circuit in a preferred embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the discharge circuit in a preferred embodiment of the present invention. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0031] In a preferred embodiment of this utility model, based on the above-mentioned problems existing in the prior art, a pre-charging circuit for a power battery is provided, such as... Figure 1 As shown, the circuit includes a battery pack 1, a main positive relay K1, a discharge pre-charge relay K2, a fast charge relay K3, a charge pre-charge relay K4, a main negative relay K5, a pre-charge resistor R1, a discharge module 2, a charging module 3, and a shunt 4. Wherein:

[0032] Battery pack 1 is used to provide the electrical energy required by various modules in the circuit and is the core energy storage component of the entire power system.

[0033] The main positive relay K1 has one end connected to the positive terminal of battery pack 1 and the other end connected to one end of discharge module 2, and is used to control the on / off state of the main discharge circuit. When the main positive relay K1 is closed, battery pack 1 can supply electrical energy to discharge module 2.

[0034] The pre-charge relay K2 is connected at one end to the positive terminal of battery pack 1 and is used to control the on / off state of the pre-charge circuit. When the pre-charge relay K2 is closed, battery pack 1 can supply electrical energy to the discharge module 2 to pre-charge it until it approaches the power supply voltage, thus completing the pre-charge. After the discharge module 2 has finished pre-charging, the pre-charge relay K2 is disconnected, and then the main positive relay K1 is closed, thereby ensuring the safety of the vehicle's power-on.

[0035] Fast charging relay K3 has one end connected to the positive terminal of battery pack 1 and the other end connected to one end of charging module 3. It is used to control the on / off state of the fast charging main circuit. When fast charging relay K3 is closed, it enables fast charging of battery pack 1.

[0036] The pre-charge relay K4 is connected at one end to the positive terminal of battery pack 1 and is used to control the on / off state of the pre-charge circuit. When the pre-charge relay K4 is closed, battery pack 1 can supply electrical energy to charging module 3 to pre-charge it. After charging module 3 is pre-charged, the pre-charge relay K4 is disconnected, and then the fast-charge relay K3 is closed.

[0037] The pre-charge resistor R1 includes a first end and a second end. The first end is connected to the other end of the pre-charge relay K4 and one end of the discharge module 2, respectively. The second end is connected to the other end of the pre-charge relay K2 and one end of the charging module 3, respectively. In the pre-charge circuit, the pre-charge resistor R1 plays a role in limiting the current, which can prevent excessive current from damaging the circuit during the pre-charge process.

[0038] The main negative relay K5 has one end connected to the negative terminal of battery pack 1, and the other end connected to discharge module 2 and charging module 3 respectively. The main negative relay K5 and the main positive relay K1 work together to control the on / off state of the entire high voltage circuit.

[0039] Specifically, the pre-charging circuit can avoid the impact of large current on the battery and other high-voltage equipment, reduce the probability of equipment damage, and improve system reliability. At the same time, a stable power-on process can also provide users with a more comfortable and safer driving experience. However, the pre-charging process to complete the charging and discharging in the traditional solution requires two pre-charging resistors, which are difficult to arrange due to the compression of the internal space of the pack, and also increase the cost of the power battery, thus affecting the price competitiveness of the power battery.

[0040] In this embodiment, the pre-charging circuit of the power battery is optimized by setting only one pre-charging resistor R1. The pre-charging resistor R1 is connected between the charging pre-charging relay K4 and the charging module 3, and between the discharging pre-charging relay K2 and the discharging module 2, so that the charging pre-charging relay K4 and the discharging pre-charging relay K2 can share the same pre-charging resistor R1.

[0041] Compared to traditional solutions, this invention can achieve the pre-charge function of the charging and discharging circuit using only a pre-charge resistor R1.

[0042] By using a shared resistor, the requirement of a pre-charge resistor is reduced, and the reduction in the number of components directly lowers material costs. Furthermore, the reduction in the number of components reduces the number of high-voltage wiring harnesses used, further reducing the overall package cost and improving product cost-effectiveness.

[0043] Meanwhile, the reduction in the number of components and high-voltage wiring harnesses lowers the difficulty of component and wiring harness arrangement, making it particularly suitable for areas with limited space, and providing greater flexibility for battery pack design and manufacturing.

[0044] In a preferred embodiment, a shunt 4 is provided between the main negative relay K5 and the negative terminal of the battery pack 1.

[0045] Specifically, a shunt 4 is installed between the negative terminal of battery pack 1 and the main negative relay K5. The shunt 4 is used to measure the current in the circuit so that the battery management system can accurately control and monitor the charging and discharging process of the battery.

[0046] Furthermore, in the initial state, the main positive relay K1, the discharge pre-charge relay K2, the fast charge relay K3, the charging pre-charge relay K4, and the main negative relay K5 are all disconnected.

[0047] In a preferred embodiment, the charging circuit is as follows: Figure 2 As shown, its charging process is as follows:

[0048] During charging, the pre-charge relay K4 and the main negative relay K5 are closed, while all other relays are open. The current flows from the positive terminal of the battery pack 1 through the pre-charge relay K4, the first end of the pre-charge resistor R1, and the second end of the pre-charge resistor R1 to the charging module 3. Then, it flows through the main negative relay K5 and the shunt 4 to the negative terminal of the battery pack 1, forming a pre-charge circuit to pre-charge the charging module 3.

[0049] After the charging module 3 has finished pre-charging, the fast charging relay K3 closes, and the pre-charging relay K4 and other relays open to switch to the charging circuit and realize the fast charging of battery pack 1.

[0050] In a preferred embodiment, the discharge circuit is as follows: Figure 3 As shown, its discharge process is as follows:

[0051] During discharge, the discharge pre-charge relay K2 and the main negative relay K5 are closed, while all other relays are open. The current flows from the positive terminal of battery pack 1 through the discharge pre-charge relay K2, the second end of the pre-charge resistor R1, and the first end of the pre-charge resistor R1 to the discharge module 2, and then through the main negative relay K5 and the shunt 4 to the negative terminal of battery pack 1, forming a discharge pre-charge circuit to pre-charge the discharge module 2.

[0052] After the discharge module 2 has completed its pre-charge, the main positive relay K1 closes, and the discharge pre-charge relay K2 and other relays open to switch to the discharge circuit, enabling the battery pack 1 to discharge normally to the discharge module 2.

[0053] In a preferred embodiment of the present invention, a power battery is provided, the power battery including the power battery pre-charging circuit as described above.

[0054] In a preferred embodiment of this utility model, a battery pack is provided, which includes the power battery as described above, further enhancing the market competitiveness of the battery pack.

[0055] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included within the protection scope of the present utility model.

Claims

1. A pre-charging circuit for a power battery, characterized in that, include: The battery pack, and a pre-charge relay and a pre-charge relay electrically connected to the positive terminal of the battery pack; A main negative relay, one end of which is connected to the negative terminal of the battery pack, and the other end of which is connected to the discharge module and the charging module respectively; The charging pre-charge relay and the discharging pre-charge relay share the same pre-charge resistor, which is connected to the charging module and the discharging module, respectively.

2. The power battery pre-charging circuit according to claim 1, characterized in that, A shunt is provided between the main negative relay and the negative terminal of the battery pack.

3. The power battery pre-charging circuit according to claim 1, characterized in that, The pre-charge resistor includes a first end and a second end. The first end is connected to the pre-charge relay and the discharge module, respectively, and the second end is connected to the pre-charge relay and the charging module, respectively. During discharge, the discharge pre-charge relay and the main negative relay are closed, and the current flows from the positive terminal of the battery pack through the discharge pre-charge relay, the second end of the pre-charge resistor, and the first end of the pre-charge resistor to the discharge module, pre-charging the discharge module. During charging, the pre-charge relay and the main negative relay are closed, and the current flows from the positive terminal of the battery pack through the pre-charge relay, the first end of the pre-charge resistor, and the second end of the pre-charge resistor to the charging module to pre-charge the charging module.

4. The power battery pre-charging circuit according to claim 1, characterized in that, Also includes: The main positive relay is connected between the positive terminal of the battery pack and the discharge module.

5. The power battery pre-charging circuit according to claim 4, characterized in that, After the discharge module is pre-charged, the main positive relay closes and the discharge pre-charge relay opens to switch to the discharge circuit.

6. The power battery pre-charging circuit according to claim 1, characterized in that, Also includes: A fast-charging relay is connected between the positive terminal of the battery pack and the charging module.

7. The power battery pre-charging circuit according to claim 6, characterized in that, After the charging module has finished pre-charging, the fast charging relay closes and the pre-charging relay opens to switch to the charging circuit.

8. A power battery, characterized in that, The power battery includes the power battery pre-charging circuit as described in any one of claims 1-7.

9. A battery pack, characterized in that, The battery pack includes the power battery as described in claim 8.

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