A dual-battery system, an electric vehicle, and a charging method thereof

Abstract

The present invention relates to the technical field of electric vehicles. The present invention discloses a dual-battery system, an electric vehicle and a charging method thereof. The system includes: a dual-battery pack, a high-voltage box and a vehicle controller; the dual-battery pack includes: a first battery pack and a second battery pack; the first battery pack and the second battery pack are connected in parallel and are both connected to the battery input interface of the high-voltage box; the high-voltage box is provided with two DC charging interfaces, one of the DC charging interfaces is connected to the output end of a first charging gun, and the other DC charging interface is connected to the output end of a second charging gun. The input ends of the first charging gun and the second charging gun are both connected to a charging pile controller; the vehicle controller communicates with the battery management unit of the high-voltage box, and the battery management unit realizes charging the dual-battery pack by simultaneously inserting two charging guns by controlling the opening and closing of the relay in the high-voltage box. Without changing the battery standard box, an additional set of the same battery pack is externally connected in parallel, and the capacity is doubled.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicles, and particularly to a dual-battery system, an electric vehicle and a charging method thereof. Background Art

[0002] The statements in this section merely mention the background art related to the present invention and do not necessarily constitute prior art.

[0003] The battery capacity is directly related to the cruising range of the vehicle. If the capacity is to be increased, generally the number of parallel connections needs to be increased within the standard battery box, and this method inevitably requires expanding the standard box body. In addition, during the development process, it is necessary to re-design and select high-voltage plugs, MSD, relays, high-voltage harnesses, etc., which will cause problems such as increased costs and technical difficulties. Summary of the Invention

[0004] To solve the deficiencies of the prior art, the present invention provides a dual-battery system, an electric vehicle and a charging method thereof; an additional set of the same battery pack is externally connected in parallel without changing the standard battery box, doubling the capacity, and the charging adopts a single charging pile with two charging guns charging in parallel to charge the dual-battery packs simultaneously, and the charging time remains basically unchanged.

[0005] In the first aspect, the present invention provides a dual-battery system;

[0006] A dual-battery system includes: a dual-battery pack, a high-voltage box and a vehicle controller; the dual-battery pack includes: a first battery pack and a second battery pack; the first battery pack and the second battery pack are connected in parallel and are both connected to the battery input interface of the high-voltage box;

[0007] The high-voltage box is provided with two DC charging interfaces, one of the DC charging interfaces is connected to the output end of the first charging gun, and the other DC charging interface is connected to the output end of the second charging gun. The input ends of the first charging gun and the second charging gun are both connected to the charging pile controller;

[0008] The vehicle controller communicates with the battery management unit of the high-voltage box, and the battery management unit controls the opening and closing of the relay in the high-voltage box to realize charging the dual-battery pack by simultaneously inserting two charging guns.

[0009] In the second aspect, the present invention provides an electric vehicle;

[0010] An electric vehicle includes the dual-battery system described in the first aspect.

[0011] In the third aspect, the present invention provides a charging method for a dual-battery system;

[0012] A charging method for a dual-battery system includes:

[0013] Plug-in gun judgment: When the charging gun is connected and the key switch is in the Off position, the charging gun and the charger send identification messages to each other, and the parameter configuration is successful;

[0014] Enter charging: After judging that the plug-in gun is successful, first close the charging pile relay, and then close the battery management system relay before charging;

[0015] Judge the charging status: When the battery management system judges that the battery is fully charged, it sends a message, and after the charging pile receives the message, it sends a confirmation termination message;

[0016] Charging end: The charging pile first disconnects the relay, and then the battery management system disconnects the relay, unlocks, and the charging ends.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] Without changing the battery standard box, an additional set of the same battery pack is externally paralleled, doubling the capacity. The charging adopts a single charging pile and dual charging gun parallel charging mode to charge the dual battery packs at the same time, and the charging time remains basically unchanged. Description of the drawings

[0019] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0020] Figure 1 It is the electrical schematic diagram of the dual battery system in Embodiment 1;

[0021] Figure 2 It is the electrical schematic diagram of the dual system high-voltage box in Embodiment 1;

[0022] Figure 3 It is the schematic diagram of the dual system charging mode in Embodiment 1;

[0023] Figure 4 It is the dual charging flow chart of the dual battery system in Embodiment 1;

[0024] Among them, 1. First relay, 2. Second relay, 3. Third relay, 4. Fourth relay, 5. Fifth relay, 6. Sixth relay, 7. Seventh relay, 8. Eighth relay, 9. Ninth relay, 10. Tenth relay, 11. Eleventh relay, 12. Second battery input positive electrode interface, 13. First battery input positive electrode interface, 14. Second heating output interface, 15. First heating output interface, 16. Second battery input negative electrode interface, 17. First battery input negative electrode interface, 18. First heating input interface, 19. Second heating input interface, 20. First compartment communication interface, 21. Second compartment communication interface, 22. Debugging interface, 23. Output positive electrode interface, 24. First DC charging positive electrode interface, 25. Second DC charging positive electrode interface, 26. Output negative electrode interface, 27. First DC charging negative electrode interface, 28. Second DC charging negative electrode interface, 29. Vehicle communication interface, 30. Charging communication interface, 31. First fuse, 32. Second fuse, 33. First current sensor, 34. Second current sensor, 35. Battery management unit, 36. Charging pile controller, 37. First charging gun, 38. Second charging gun, 39. Vehicle controller, 40. Pre-charge resistor. Detailed implementation mode

[0025] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0026] It should be noted that the terms used herein are only for describing specific implementation modes and are not intended to limit the exemplary implementation modes according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products or devices.

[0027] Embodiment 1

[0028] This embodiment provides a dual-battery system;

[0029] Such as Figure 1 And Figure 3As shown in the figure, a dual-battery system includes: a dual-battery pack, a high-voltage box, and a vehicle controller; the dual-battery pack includes: a first battery pack and a second battery pack; the first battery pack and the second battery pack are connected in parallel and are both connected to the battery input interface of the high-voltage box;

[0030] The high-voltage box is provided with two DC charging interfaces, one of the DC charging interfaces is connected to the output end of the first charging gun 37, and the other DC charging interface is connected to the output end of the second charging gun 38. The input ends of the first charging gun and the second charging gun are both connected to the charging pile controller 36;

[0031] The vehicle controller 39 communicates with the battery management unit 35 of the high-voltage box. The battery management unit 35 realizes charging the dual-battery pack by simultaneously inserting two charging guns by controlling the opening and closing of the relays in the high-voltage box.

[0032] Further, as Figure 2 shown in the figure, the high-voltage box includes: a first battery input positive interface 13. The first battery input positive interface 13 is connected to the first relay 1 through the first fuse 31. The first relay 1 is connected to the input end of the first current sensor 33. The output end of the first current sensor 33 is connected to the second relay 2. The second relay 2 is connected to the output positive interface 23;

[0033] The high-voltage box further includes: a second battery input positive interface 12. The second battery input positive interface 12 is connected to the third relay 3 through the second fuse 32. The third relay 3 is connected to the input end of the second current sensor 34. The output end of the second current sensor 34 is connected to the second relay.

[0034] Further, the output end of the second current sensor is also connected to the first end of the fourth relay 4. The second end of the fourth relay 4 is connected to the pre-charge resistor 40. The pre-charge resistor 40 is connected to the output positive interface;

[0035] The output end of the second current sensor is also connected to the first DC charging positive interface 24 of the high-voltage box through the fifth relay 5;

[0036] The output end of the second current sensor is also connected to the second DC charging positive interface 25 of the high-voltage box through the sixth relay 6.

[0037] Further, the high-voltage box further includes: a first heating output interface 15 and a second heating output interface 14. The first heating output interface 15 and the second heating output interface 14 are both connected to the output end of the second current sensor through the seventh relay 7.

[0038] Further, the high-voltage box further includes: a first battery input negative electrode interface 17 and a second battery input negative electrode interface 16; both the first battery input negative electrode interface 17 and the second battery input negative electrode interface 16 are connected to the negative electrode interface 26 of the output end of the high-voltage box through an eighth relay 8.

[0039] Further, the first battery input negative electrode interface is also connected to a first DC charging negative electrode interface 27 through a ninth relay 9;

[0040] The first battery input negative electrode interface is also connected to a second DC charging negative electrode interface 28 through a tenth relay 10.

[0041] Further, the high-voltage box further includes: a first heating input interface 18 and a second heating input interface 19, and both the first heating input interface and the second heating input interface are connected to the first battery input negative electrode interface through an eleventh relay 11.

[0042] Further, the high-voltage box further includes:

[0043] A first inter-pack communication interface 20 is connected to the battery pack; a second inter-pack communication interface 21 is connected to the battery pack; a vehicle communication interface 29 is connected to the vehicle; a charging communication interface 30 is connected to the vehicle charging interface, and a debugging interface 22 is connected to the vehicle debugging port.

[0044] Further, the first battery input positive electrode interface is connected to the positive electrode of each single battery of the first battery pack; the second battery input positive electrode interface is connected to the positive electrode of each single battery of the second battery pack;

[0045] The first battery input negative electrode interface is connected to the negative electrode of each single battery of the first battery pack; the second battery input negative electrode interface is connected to the negative electrode of each single battery of the second battery pack.

[0046] Further, as Figure 1 shown, the first heating input interface is connected to the heating wire of each single battery of the first battery pack; the second heating input interface is connected to the heating wire of each single battery of the second battery pack.

[0047] Further, the first inter-pack communication interface is connected to the temperature sensor of each single battery; the second inter-pack communication interface is connected to the temperature sensor of each single battery.

[0048] Figure 1It is the electrical schematic diagram of a dual-battery system. The entire battery system is divided into two major parts: a dual-battery pack and a high-voltage box. In this invention, an additional independent battery pack is added on the basis of the original battery pack. The two battery packs are connected in parallel to the high-voltage box. Under the same operating conditions, the discharge current of each battery subsystem in the dual-battery system is half of that when a single battery system operates independently. Since the battery capacity is affected by the magnitude of the discharge current, the battery capacity is indirectly increased. The high-voltage box mainly plays the roles of on-off, control, or protection during the charge and discharge of the battery pack, and communicates with the Vehicle Control Unit.

[0049] Figure 2 It is the internal electrical schematic diagram of the system high-voltage box. The Battery Management Unit receives sensor signals and controls the on-off of the relays in the high-voltage box. The insulation detector detects whether there is insulation leakage in the high-voltage box. A maintenance switch, a branch relay, and a current sensor are set for each input branch of each battery in the box. The second relay and the eighth relay control the on-off of the positive and negative circuits of the dual-battery pack. The fourth relay and the pre-charge resistor form a pre-charge circuit to prevent the current from damaging the relay when the system is directly powered on. Voltage acquisitions are provided at both ends of the second relay, which are responsible for detecting the battery terminal voltage and the motor terminal voltage. The seventh relay controls the heating circuits of the two battery packs. In addition, the high-voltage box is provided with 2 charging interfaces to support dual-gun charging.

[0050] Figure 3 It is the schematic diagram of the system dual-charging mode. The charging pile adopted is different from the traditional charging pile. The charging pile control system uses 1 CAN bus to control 2 charging guns. The dual-charging interfaces of the high-voltage box are also controlled by 1 CAN line. During the charging process, after the charging guns are connected in parallel to the charging interfaces of the high-voltage box, the charging pile control system communicates with the battery management system through the CAN bus to confirm the connection of each charging gun and charging interface. Only after confirmation can the normal charging process be entered. If a certain charging interface fails, single-gun charging can still be used.

[0051] Closing logic of the second relay: After the low-voltage power supply is powered on and the Battery Management System (BMS) completes self-checking and there is no fault alarm from the BMS, the BMS waits for the Vehicle Control Unit (VCU) to send an instruction to allow the second relay to close. After receiving the closing instruction, the BMU closes the second relay, and the relay status feedbacks a closing signal after the second relay is closed.

[0052] Second relay disconnection logic: When the Battery Management System (BMS) receives a power-off instruction request sent by the whole vehicle and confirms no abnormalities, it disconnects the second relay. When a level 1 alarm occurs in the battery system, the BMS first sends a request to disconnect the second relay, and can only disconnect the second relay after being permitted by the vehicle controller. If the vehicle controller does not respond, the BMS disconnects the main positive relay after 35s.

[0053] Embodiment 2

[0054] This embodiment provides an electric vehicle;

[0055] An electric vehicle includes the dual battery system described in Embodiment 1.

[0056] Embodiment 3

[0057] As Figure 4 shown, this embodiment provides a charging method for a dual battery system, including:

[0058] Step 301: Plug-in gun judgment: When the charging gun (single gun or double gun) is plugged in, the key switch is in the Off gear, and the charging gun and the charger send identification messages to each other, and the parameter configuration is successful;

[0059] Step 302: Enter charging: After judging that the gun is plugged in successfully, first close the charging pile relay, and then close the Battery Management System (BMS) relay to start charging;

[0060] Step 303: Judge the charging status: When the BMS judges that the battery is fully charged, it sends a message, and after receiving the message, the charging pile sends a confirmation termination message;

[0061] Step 304: Charging end: The charging pile first disconnects the relay, and then the BMS disconnects the relay, unlocks, and the charging ends.

[0062] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A dual-battery system, characterized in that, Including: Dual battery packs, a high-voltage box, and a vehicle controller; The dual battery packs include a first battery pack and a second battery pack; the first battery pack and the second battery pack are connected in parallel and are both connected to the battery input interface of the high-voltage box; The high-voltage box is provided with two DC charging interfaces, one of the DC charging interfaces is connected to the output end of the first charging gun, and the other DC charging interface is connected to the output end of the second charging gun. The input ends of the first charging gun and the second charging gun are both connected to the charging pile controller; The vehicle controller communicates with the battery management unit of the high-voltage box, and the battery management unit realizes charging the dual battery packs by simultaneously inserting two charging guns by controlling the opening and closing of the relay in the high-voltage box; The high-voltage box includes a first battery input positive interface, the first battery input positive interface is connected to a first relay through a first fuse, the first relay is connected to the input end of a first current sensor, the output end of the first current sensor is connected to a second relay, and the second relay is connected to the output positive interface; The high-voltage box further includes a second battery input positive interface, the second battery input positive interface is connected to a third relay through a second fuse, the third relay is connected to the input end of a second current sensor, and the output end of the second current sensor is connected to the second relay; The output end of the second current sensor is also connected to the first end of a fourth relay, the second end of the fourth relay is connected to a pre-charge resistor, and the pre-charge resistor is connected to the output positive interface; the fourth relay and the pre-charge resistor form a pre-charge circuit to prevent the current from damaging the relay when the system is directly powered on; the seventh relay controls the heating circuits of the two battery packs; the output end of the second current sensor is also connected to the first DC charging positive interface of the high-voltage box through a fifth relay; the output end of the second current sensor is also connected to the second DC charging positive interface of the high-voltage box through a sixth relay; The high-voltage box further includes a first heating output interface and a second heating output interface, and both the first heating output interface and the second heating output interface are connected to the output end of the second current sensor through a seventh relay; The high-voltage box further includes a first heating input interface and a second heating input interface, and both the first heating input interface and the second heating input interface are connected to the first battery input negative interface through an eleventh relay; The first heating input interface is connected to the heating wires of each single battery of the first battery pack; the second heating input interface is connected to the heating wires of each single battery of the second battery pack.

2. The dual-battery system according to claim 1, characterized in that, The high-voltage box further includes a first battery input negative interface and a second battery input negative interface; both the first battery input negative interface and the second battery input negative interface are connected to the output negative interface of the high-voltage box through an eighth relay.

3. The dual-battery system according to claim 2, wherein The first battery input negative interface is also connected to the first DC charging negative interface through a ninth relay; The first battery input negative interface is also connected to the second DC charging negative interface through a tenth relay.

4. A dual-battery system according to claim 3, characterized in that, The first battery input positive electrode interface is connected to the positive electrode of each single battery of the first battery pack; the second battery input positive electrode interface is connected to the positive electrode of each single battery of the second battery pack; The first battery input negative electrode interface is connected to the negative electrode of each single battery of the first battery pack; the second battery input negative electrode interface is connected to the negative electrode of each single battery of the second battery pack; The first inter-compartment communication interface is connected to the temperature sensor of each single battery; the second inter-compartment communication interface is connected to the temperature sensor of each single battery.

5. An electric vehicle, characterized in that, It includes the dual-battery system according to any one of claims 1-4.

6. A charging method applicable to the dual-battery system according to any one of claims 1-4, characterized by comprising: Plug-in gun judgment: When the charging gun is plugged in and the key switch is in the Off gear, the charging gun and the charger send identification messages to each other, and the parameter configuration is successful; Enter charging: After judging that the plug-in gun is successful, first close the charging pile relay, and then close the battery management system relay before charging; Judge the charging state: When the battery management system judges that the battery is fully charged, it sends a message, and after the charging pile receives the message, it sends a confirmation termination message; Charging end: The charging pile first disconnects the relay, and then the battery management system disconnects the relay, unlocks, and the charging ends.

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