A battery pack charging system, method, device, and vehicle

Abstract

The present disclosure provides a battery pack charging system, method, device and vehicle, relating to the technical field of charging management, the system comprising: a battery pack, a main positive relay, a main negative relay, a voltage division relay, a direct current charging positive relay, a direct current charging negative relay, a direct current charging port; the first end of the main positive relay is connected with the positive electrode of the battery pack, the first end of the main negative relay is connected with the negative electrode of the battery pack, the first end of the voltage division relay is connected to the battery pack, the battery pack is divided into a voltage division 1 section and a voltage division 2 section, the second end of the voltage division relay is connected with the second end of the main positive relay and the first end of the direct current charging negative relay, the second end of the direct current charging negative relay is connected with the second end of the main negative relay, the positive electrode of the direct current charging port is connected with the second end of the main positive relay through the direct current charging positive relay, and the negative electrode of the direct current charging port is connected with the second end of the main negative relay. The present disclosure can improve the charging efficiency of the 400V charging pile for the 800V battery pack charging.

Description

Technical Field

[0001] This disclosure relates to the field of charging management technology, specifically to a battery pack charging system, method, apparatus, and vehicle. Background Technology

[0002] Currently, most pure electric vehicles and DC charging stations on the market use a 400V voltage platform. However, with advancements in demand and technology, many new energy vehicle manufacturers have begun to launch 800V high-voltage platform models, which not only offer faster charging speeds but also significantly contribute to reduced energy consumption and increased range. However, the commonly used 400V low-voltage charging stations are incompatible with charging 800V high-voltage platform models.

[0003] Chinese utility model patent CN 219544538 U discloses an electric vehicle charging architecture compatible with both 400V and 800V charging voltages. When using 400V low-voltage charging, two battery modules within the battery pack, each with a voltage of 400V, are charged in parallel, thus achieving compatibility with 400V charging stations. However, this patent's solution has high requirements for the consistency between the first and second battery modules. If the parameters of the first and second battery modules are inconsistent, it is difficult to achieve optimal voltage and current matching during parallel charging. Summary of the Invention

[0004] To address the problems of the prior art, this disclosure provides a battery pack charging system, method, apparatus, and vehicle. Specifically, it includes the following technical solutions:

[0005] A first aspect of the present disclosure provides a battery pack charging system, including: a battery pack, a main positive relay, a main negative relay, a voltage divider relay, a DC charging positive relay, a DC charging negative relay, and a DC charging port;

[0006] The first terminal of the main positive relay is connected to the positive terminal of the battery pack, the first terminal of the main negative relay is connected to the negative terminal of the battery pack, the first terminal of the voltage divider relay is connected to the inside of the battery pack, dividing the battery pack into voltage divider segment 1 and voltage divider segment 2, the second terminal of the voltage divider relay is connected to the second terminal of the main positive relay and the first terminal of the DC charging negative relay, the second terminal of the DC charging negative relay is connected to the second terminal of the main negative relay, the DC charging port is used to connect to the charging pile, the positive terminal of the DC charging port is connected to the second terminal of the main positive relay through the DC charging positive relay, and the negative terminal of the DC charging port is connected to the second terminal of the main negative relay;

[0007] The voltage divider relay is used to connect the first and second voltage dividers inside the pack to the DC charging port when charging at low voltage, so as to charge the first and second voltage dividers inside the pack respectively.

[0008] Optionally, a pre-charging circuit is also connected in parallel across the two ends of the main positive relay. The pre-charging circuit is composed of a pre-charging relay and a pre-charging resistor connected in series.

[0009] Optionally, the voltage of the first voltage divider segment within the battery pack is 300V-500V, and / or the voltage of the second voltage divider segment within the battery pack is 300V-500V.

[0010] A second aspect of this disclosure provides a battery pack charging method, including:

[0011] To obtain the charging capacity of charging stations;

[0012] If the charging capacity of the charging station meets the charging needs of the battery pack, the battery pack will be charged through the charging station.

[0013] If the charging capacity of the charging station does not meet the charging requirements of the battery pack, the charging station will charge the battery pack through the first stage of voltage division. After the first stage of voltage division is completed, the second stage of voltage division will be charged.

[0014] Optionally, if the charging capacity of the charging pile meets the charging requirements of the battery pack, the main positive relay, the main negative relay, and the DC charging positive relay are closed to charge the battery pack.

[0015] Optionally, if the charging capacity of the charging pile does not meet the charging requirements of the battery pack, close the main positive relay, the voltage divider relay, the DC charging positive relay, and the DC charging negative relay to charge the first voltage divider segment of the pack; after the first voltage divider segment of the pack is fully charged, disconnect the DC charging negative relay and the main positive relay, and close the main negative relay to charge the second voltage divider segment of the pack.

[0016] Optionally, once the first stage of charging within the pack is complete, the charging mode of the charging station can be changed to constant voltage mode.

[0017] A third aspect of this disclosure provides a battery pack charging device, comprising:

[0018] Battery management system, used to obtain the charging capacity of the charging station;

[0019] The charging control system is used to charge the battery pack through the charging pile if the charging capacity of the charging pile meets the charging requirements of the battery pack; or, if the charging capacity of the charging pile does not meet the charging requirements of the battery pack, to charge the first stage of the internal voltage division of the battery pack through the charging pile, and after the first stage of internal voltage division is completed, to charge the second stage of internal voltage division of the battery pack.

[0020] Optionally, the battery management system obtains the charger's maximum output capacity message and determines whether the charging pile's charging capacity meets the battery pack's charging requirements based on the charger's maximum output capacity message.

[0021] A fourth aspect of this disclosure provides a vehicle that includes a battery pack charging system provided in the first aspect or a battery pack charging device provided in the third aspect, wherein the vehicle is charged using a battery pack charging method provided in the second aspect.

[0022] The beneficial effects of the technical solutions provided in this disclosure are:

[0023] In this embodiment, the high-voltage (800V) battery pack is divided into two voltage divider segments: internal voltage divider segment 1 and internal voltage divider segment 2. If a low-voltage (400V) charging station is used during charging, the internal voltage divider segment 1 and internal voltage divider segment 2 are charged sequentially by controlling the on / off state of each relay. This allows for optimal matching of charging voltage and current based on the actual state of internal voltage divider segment 1 and internal voltage divider segment 2 during charging, ensuring charging efficiency. Furthermore, this solution does not have special requirements for the consistency between internal voltage divider segment 1 and internal voltage divider segment 2, and strict matching between the two is not necessary.

[0024] Advantages of this disclosure in additional aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a battery pack charging system provided in an embodiment of this disclosure;

[0027] Figure 2 This is a schematic diagram of a battery pack charging method provided in an embodiment of this disclosure;

[0028] Figure 3 This is a schematic diagram of a battery pack charging device provided in an embodiment of this disclosure. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0030] Most DC charging stations on the market are low-voltage (400V platform), which cannot meet the charging needs of 800V platform electric vehicles, thus requiring compatibility design. The current common solution is to divide the 800V battery pack into two parallel 400V modules, charging both modules simultaneously. This solution is feasible under ideal conditions, but in practical applications, it's difficult to ensure that the parameters of the two modules are identical. Therefore, during parallel charging, the charging station's output current and voltage can only be matched according to the parameters of the smaller module. When the two modules differ significantly, charging becomes difficult.

[0031] To address the aforementioned problems, this disclosure provides a battery pack charging system. Figure 1 This is a schematic diagram of a battery pack charging system provided in an embodiment of this disclosure. See also... Figure 1 The system includes: a battery pack, a main positive relay K2, a main negative relay K4, a voltage divider relay K3, a DC charging positive relay K6, a DC charging negative relay K5, and a DC charging port.

[0032] The first terminal of the main positive relay K2 is connected to the positive terminal of the battery pack, the first terminal of the main negative relay K4 is connected to the negative terminal of the battery pack, the first terminal of the voltage divider relay K3 is connected to the inside of the battery pack, dividing the battery pack into voltage divider segment 1 and voltage divider segment 2. The second terminal of the voltage divider relay K3 is connected to the second terminal of the main positive relay K2 and the first terminal of the DC charging negative relay K5. The second terminal of the DC charging negative relay K5 is connected to the second terminal of the main negative relay K4. The DC charging port is used to connect to the charging pile. The positive terminal of the DC charging port is connected to the second terminal of the main positive relay through the DC charging positive relay K6, and the negative terminal of the DC charging port is connected to the second terminal of the main negative relay.

[0033] The voltage divider relay K3 is used to connect the first and second voltage dividers inside the package to the DC charging port when charging at a low voltage of 400V, so that the first and second voltage dividers inside the package can be charged respectively.

[0034] A pre-charging circuit is connected in parallel across the main positive relay K2. The pre-charging circuit consists of a pre-charging relay K1 and a pre-charging resistor connected in series. Before closing the main positive relay, the pre-charging relay should be closed first to charge the pre-charging resistor, so that the voltage and current gradually increase, avoiding the impact of instantaneous circuit conduction when the main positive relay is closed directly.

[0035] By controlling the on / off state of each relay to change the circuit topology, compatibility with both 400V and 800V charging stations is achieved. The voltage divider relays divide the battery pack into two voltage divider segments: segment 1 and segment 2. These two segments are typically designed to have the same voltage, but can also be designed differently depending on actual needs, as long as they match the charging capacity of the 400V charging station. For example, in some implementations, the voltage of segment 1 within the battery pack can be 300V-500V, and the voltage of segment 2 can also be 300V-500V.

[0036] Figure 2 This is a schematic diagram of a battery pack charging method further provided by an embodiment of the present disclosure, based on the battery pack charging system provided above. Figure 2 As shown, the method includes:

[0037] To obtain the charging capacity of charging stations;

[0038] If the charging capacity of the charging station meets the charging needs of the battery pack, the battery pack will be charged through the charging station.

[0039] If the charging capacity of the charging station does not meet the charging requirements of the battery pack, the charging station will charge the battery pack through the first stage of voltage division. After the first stage of voltage division is completed, the second stage of voltage division will be charged.

[0040] First, the charging capacity of the charging pile connected to the DC charging port is obtained. This process can be completed within the Battery Management System (BMS). Before starting DC charging, the BMS determines whether the DC charging pile's capacity meets the current vehicle charging requirements based on the CML message (maximum output capacity of the charger) sent by the charging pile. If it does, meaning the charging pile is an 800V platform and matches the vehicle's power battery, then the main positive relay K2, main negative relay K4, and DC charging positive relay K6 are closed, while the voltage divider relay K3 and DC charging negative relay K5 remain open. At this time, the two ends of the battery pack are connected to the two ends of the DC charging port, and charging begins.

[0041] If the charging capacity of the charging pile does not meet the charging requirements of the battery pack, the main positive relay K2 and the voltage divider relay K3 are closed, while the DC charging positive relay K6 and the DC charging negative relay K5 are closed. The main negative relay K4 remains open, prioritizing charging of the first voltage divider stage within the battery pack. After the first voltage divider stage is fully charged, the BMS must first change the charging mode of the DC charging pile to constant voltage mode, maintaining the entire vehicle at a constant voltage. Then, the DC charging negative relay K5 and the main positive relay K2 are opened, and the main negative relay K4 is closed, forming a high-voltage closed circuit for the second voltage divider stage within the battery pack. At this point, the BMS changes the charging mode back to constant current mode to charge the second voltage divider stage. Charging both the first and second voltage dividers separately ensures that the charging pile can fully match the parameters of the first and second voltage dividers during charging, guaranteeing charging efficiency.

[0042] When the vehicle is in discharge mode, simply close the main positive relay K2 and the main negative relay K4 to connect the battery pack to the vehicle load and discharge it to the outside.

[0043] Figure 3 This is a schematic diagram of a battery pack charging device provided in an embodiment of this disclosure, as shown below. Figure 3 As shown, the device includes:

[0044] Battery management system, used to obtain the charging capacity of the charging station;

[0045] The charging control system is used to charge the battery pack through the charging pile if the charging capacity of the charging pile meets the charging requirements of the battery pack; or, if the charging capacity of the charging pile does not meet the charging requirements of the battery pack, to charge the first stage of the internal voltage division of the battery pack through the charging pile, and after the first stage of internal voltage division is completed, to charge the second stage of internal voltage division of the battery pack.

[0046] The battery pack charging device provided in the above embodiments is illustrated by the division of the aforementioned hardware modules during battery pack charging. In practical applications, the aforementioned hardware modules can be replaced with other hardware modules with similar or identical functions as needed, or the function of a certain hardware module can be assigned to different hardware modules. Furthermore, the battery pack charging device and the battery pack charging method embodiment provided in the above embodiments belong to the same concept; their specific implementation process is detailed in the method embodiment and will not be repeated here.

[0047] In some embodiments of this disclosure, a vehicle is further provided, which is an electric vehicle that uses a battery pack for energy storage, including the battery pack charging system or battery pack charging device provided above, and the vehicle is charged using the battery pack charging method provided above.

[0048] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A battery pack charging system, characterized in that, include: Battery pack, main positive relay, main negative relay, voltage divider relay, DC charging positive relay, DC charging negative relay, DC charging port; The first terminal of the main positive relay is connected to the positive terminal of the battery pack, the first terminal of the main negative relay is connected to the negative terminal of the battery pack, the first terminal of the voltage divider relay is connected to the inside of the battery pack, dividing the battery pack into voltage divider segment 1 and voltage divider segment 2, the second terminal of the voltage divider relay is connected to the second terminal of the main positive relay and the first terminal of the DC charging negative relay, the second terminal of the DC charging negative relay is connected to the second terminal of the main negative relay, the DC charging port is used to connect to the charging pile, the positive terminal of the DC charging port is connected to the second terminal of the main positive relay through the DC charging positive relay, and the negative terminal of the DC charging port is connected to the second terminal of the main negative relay; The voltage divider relay is used to connect the first voltage divider segment and the second voltage divider segment inside the pack to the DC charging port respectively when charging at low voltage, so as to charge the first voltage divider segment and the second voltage divider segment inside the pack respectively. Specific charging process This includes closing the main positive relay, the voltage divider relay, the DC charging positive relay, and the DC charging negative relay to charge the first voltage divider stage within the battery pack. After the first voltage divider stage within the battery pack is fully charged, the BMS first changes the charging mode of the DC charging pile to constant voltage mode, while the entire vehicle is simultaneously maintained at constant voltage. Then, the DC charging negative relay and the main positive relay are disconnected, and the main negative relay is closed to form a high-voltage closed circuit for the second voltage divider stage within the battery pack. At this point, the BMS changes the charging mode to constant current mode to charge the second voltage divider stage within the battery pack.

2. The battery pack charging system as described in claim 1, characterized in that, The main positive relay is also connected in parallel with a pre-charging circuit, which consists of a pre-charging relay and a pre-charging resistor connected in series.

3. The battery pack charging system as described in claim 1, characterized in that, The voltage of the first voltage divider segment inside the battery pack is 300V-500V, and / or the voltage of the second voltage divider segment inside the battery pack is 300V-500V.

4. A battery pack charging method, implementing the battery pack charging system as described in any one of claims 1-3, characterized in that, include: To obtain the charging capacity of charging stations; If the charging capacity of the charging station meets the charging needs of the battery pack, the battery pack will be charged through the charging station. If the charging capacity of the charging station does not meet the charging requirements of the battery pack, the charging station will charge the battery pack through the first stage of voltage division. After the first stage of voltage division is completed, the second stage of voltage division will be charged.

5. A battery pack charging method as described in claim 4, characterized in that, If the charging capacity of the charging pile meets the charging requirements of the battery pack, the main positive relay, the main negative relay, and the DC charging positive relay are closed to charge the battery pack.

6. A battery pack charging method as described in claim 4, characterized in that, If the charging capacity of the charging pile does not meet the charging requirements of the battery pack, close the main positive relay, the voltage divider relay, the DC charging positive relay, and the DC charging negative relay to charge the first voltage divider segment of the pack; after the first voltage divider segment of the pack is fully charged, disconnect the DC charging negative relay and the main positive relay, and close the main negative relay to charge the second voltage divider segment of the pack.

7. A battery pack charging method as described in claim 6, characterized in that, Once the first stage of charging within the battery pack is complete, switch the charging station to constant voltage mode.

8. A battery pack charging device, implementing the battery pack charging system as described in any one of claims 1-3, characterized in that, include: Battery management system, used to obtain the charging capacity of the charging station; The charging control system is used to charge the battery pack through the charging pile if the charging capacity of the charging pile meets the charging requirements of the battery pack; or, if the charging capacity of the charging pile does not meet the charging requirements of the battery pack, to charge the first stage of the internal voltage division of the battery pack through the charging pile, and after the first stage of internal voltage division is completed, to charge the second stage of internal voltage division of the battery pack.

9. A battery pack charging device as described in claim 8, characterized in that, The battery management system obtains the charger's maximum output capacity message and determines whether the charging pile's charging capacity meets the battery pack's charging requirements based on the charger's maximum output capacity message.

10. A vehicle, characterized in that, The battery pack charging system includes a battery pack charging system as described in any one of claims 1-3 or a battery pack charging device as described in any one of claims 8-9, wherein the vehicle is charged using a battery pack charging method as described in any one of claims 4-7.

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