Multi-branch battery control system and method and vehicle

Abstract

The invention provides a multi-branch battery control system and method and a vehicle, and the system comprises a first switching circuit which comprises a first input end and a first output end, the first input end is connected with the negative electrode of each battery in any battery pack, the first output end is connected with a first confluence point, and the first confluence point is the confluence point of the negative electrode of each load circuit; the second switching circuit comprises a plurality of second input ends and a second output end, any second input end is connected with the negative electrode of any battery in any battery pack, and the second output end is connected with the first confluence point; the pre-charging circuit is connected between a second confluence point and the positive electrode of the load, and the second confluence point is the confluence point of the positive electrodes of the batteries; a third switching circuit connected between the second confluence point and the positive electrode of the load circuit; contactor adhesion caused in the load operation and power-on process can be effectively prevented, and the safety of the multi-branch battery control system is improved.

Description

Technical Field

[0001] This invention relates to the field of battery system technology, specifically to a multi-branch battery control system and method, and a vehicle. Background Technology

[0002] Currently, new energy electric heavy-duty trucks are gradually developing towards larger battery capacities, making multi-branch battery systems a growing trend. Many battery manufacturers, considering the issue of individual cell consistency and the potential for overcharging and over-discharging at the end of the battery system's charging and discharging cycle, incorporate contactors into the battery branches to address this problem. However, this introduces a risk of high-current surges during power-on / off cycles and in parallel connections between branches. Therefore, there is a risk of high-current surges during power-on / off cycles and in parallel connections between batteries. Summary of the Invention

[0003] In view of this, the embodiments of the present invention aim to provide a multi-branch battery control system and method, and a vehicle, to solve the problem of overcharging and over-discharging of battery cells caused by circulating current in the later branch circuits, effectively prevent contactor sticking during load operation and power-on process, and improve the safety of the multi-branch battery control system.

[0004] According to one aspect of the present invention, an embodiment of the present invention provides a multi-branch battery control system, comprising: a first switching circuit including a first input terminal and a first output terminal, the first input terminal being connected to the negative terminal of each battery in any battery pack, the first output terminal being connected to a first busbar for balancing the battery packs when closed, wherein the battery pack includes at least two associated batteries, and the first busbar is a busbar for the negative terminals of each load circuit; a second switching circuit including a plurality of second input terminals and a second output terminal, wherein any second input terminal is connected to the negative terminal of any battery in any battery pack, and the second output terminal is connected to the first busbar for balancing the batteries in any battery pack when closed; a pre-charging circuit connected between the second busbar and the positive terminal of the load, wherein the second busbar is a busbar for the positive terminals of each battery; and a third switching circuit connected between the second busbar and the positive terminal of the load circuit.

[0005] In one embodiment, the first switching circuit includes a first resistor and a first switching transistor; a first terminal of the first switching transistor is connected to the negative terminal of any of the battery packs through the first resistor, and a second terminal of the first switching transistor is connected to the first bus point.

[0006] In one embodiment, the pre-charging circuit includes a second resistor and a fourth switching circuit, wherein a first terminal of the fourth switching circuit is connected to the second bus point through the second resistor, and a second terminal of the fourth switching circuit is connected to the negative terminal of the load circuit.

[0007] In one embodiment, the load circuit includes a plurality of first loads, the first loads being controller loads; the fourth switching circuit includes a plurality of second switching transistors, the first terminal of any second switching transistor being connected to a second resistor, and the second terminal of any second switching transistor being connected to the positive terminal of one of the first loads.

[0008] In one embodiment, the third switching circuit includes a plurality of first control switches, any one of which is connected between the second bus point and the positive terminal of one of the first loads.

[0009] In one embodiment, the load circuit includes a plurality of second loads, the second loads being resistive loads; the system further includes a third resistor and a third switch; the first terminal of the third switch is connected to the first bus point through the third resistor, and the second terminal of the third switch is connected to the negative terminal of the second load.

[0010] In one embodiment, the second switching circuit includes: a plurality of second control switches, any one of which is connected between the negative terminal of any of the batteries in any of the battery packs and the first busbar.

[0011] According to another aspect of the present invention, an embodiment of the present invention provides a multi-branch battery control method, applied to the aforementioned multi-branch battery control system. The method includes: detecting the voltage difference between any two battery packs; if the voltage difference is greater than a reference voltage, controlling the output voltage of the first battery pack with the larger voltage and discharging it to each load circuit until the voltage difference between the battery packs is less than or equal to the reference voltage; if the voltage difference is less than or equal to the reference voltage, controlling the voltage of each battery pack to be clamped to the same voltage and supplying power to each load circuit.

[0012] In one embodiment, the step of controlling the voltage of each battery pack to be clamped to the same voltage and controlling the power-on operation of each load circuit if the voltage difference is less than or equal to the reference voltage includes: if the voltage difference is less than or equal to the reference voltage, controlling the first switching circuit connected to the negative terminal of the first battery pack to close, so that each battery in the first battery pack is turned on to the pre-charge circuit for discharge; then controlling the second switching circuit connected to the negative terminal of each battery in the first battery pack to close, so that the voltage between the negative terminal of each battery in the first battery pack and the first busbar is close to the voltage between the second busbar and the first busbar; controlling the first switching circuit connected to the negative terminal of the second battery pack to close, so that the negative terminal voltages of each battery in the first battery pack and the second battery pack are clamped to the same voltage; controlling the second switching circuit connected to the negative terminal of each battery in the second battery pack to close, while simultaneously controlling the first switching circuit connected to the negative terminal of the first battery pack and the first switching circuit connected to the negative terminal of the second battery pack to open.

[0013] According to another aspect of the present invention, one embodiment of the present invention provides a vehicle including the aforementioned multi-branch battery control system.

[0014] This invention provides a multi-branch battery control system and method, and a vehicle. The system includes: a first switching circuit, comprising a first input terminal and a first output terminal, wherein the first input terminal is connected to the negative terminal of each battery in any battery pack, and the first output terminal is connected to a first busbar for balancing the battery packs when closed; the battery packs include at least two associated batteries, and the first busbar is a busbar for the negative terminals of each load circuit; a second switching circuit, comprising multiple second input terminals and a second output terminal, wherein any second input terminal is connected to the negative terminal of any battery in any battery pack, and the second output terminal is connected to the first busbar for balancing the batteries in any battery pack when closed; a pre-charging circuit, connected between the second busbar and the positive terminal of the load, wherein the second busbar is a busbar for the positive terminals of each battery; and a third switching circuit, connected between the second busbar and the positive terminal of the load circuit, which effectively prevents contactor sticking during load operation and power-on, thereby improving the safety of the multi-branch battery control system. Attached Figure Description

[0015] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0016] Figure 1 The diagram shown is a structural schematic of a multi-branch battery control system provided in an embodiment of this application.

[0017] Figure 2 The diagram shown is a circuit diagram of a multi-branch battery control system provided in an embodiment of this application.

[0018] Figure 3 The diagram shown is a flowchart of a multi-branch battery control method provided in an embodiment of this application.

[0019] Figure 4 The diagram shown is an example schematic of a multi-branch battery control method provided in an embodiment of this application. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Furthermore, in exemplary embodiments, since the same reference numerals denote the same components having the same structure or the same steps of the same method, if one embodiment has been described by way of example, then in other exemplary embodiments only structures or methods different from those described in the embodiment will be described.

[0022] Throughout the specification and claims, when a component is described as being “connected” to another component, that component may be “directly connected” to the other component or “electrically connected” to the other component via a third component. Furthermore, unless explicitly stated otherwise, the term “comprising” and its corresponding terms should be understood only to include the stated component and not to exclude any other component.

[0023] In related technologies, new energy electric heavy-duty trucks are gradually developing towards larger capacity, and multi-branch batteries have become a development trend. Most battery manufacturers, considering the potential for overcharging and over-discharging due to individual cell inconsistency issues, incorporate contactors into their batteries. Therefore, there is a risk of high-current surges when powering on and off between batteries and when paralleling between branches. Currently, the multi-in-one controllers used in new energy electric heavy-duty trucks are limited by space constraints, posing a challenge to the internal layout of controllers with multiple branches and integrated battery high-voltage boxes. As the batteries in multiple branches age and degrade, the inconsistency problem of the cells will become prominent. The mainstream battery manufacturers in the market use a solution of paralleling multiple branches, which brings the risk of circulating current in the branches, overcharging, and over-discharging of the cells later on. To solve the problems of overcharging and over-discharging of cells, contactors are added, but this increases the risk of branch adhesion in parallel.

[0024] To address the issue of overcharging and over-discharging of battery cells caused by circulating currents in the later branches of the battery, this application provides a multi-branch battery control system. Figure 1 The diagram shown is a structural schematic of a multi-branch battery control system according to an embodiment of this application. Figure 1 As shown, the multi-branch battery control system includes: The first switching circuit includes a first input terminal and a first output terminal. The first input terminal is connected to the negative terminal of each battery in any battery pack, and the first output terminal is connected to a first busbar for balancing the battery packs when closed. The battery pack includes at least two associated batteries, and the first busbar N is the busbar for the negative terminal of each load circuit. The second switching circuit includes multiple second input terminals and one second output terminal. Each second input terminal is connected to the negative terminal of any battery in any battery pack, and the second output terminal is connected to the first busbar, which is used to balance the batteries in any battery pack when closed. A pre-charging circuit is connected between the second bus point P0 and the positive terminal of the load, wherein the second bus point P0 is the bus point for the positive terminal of each battery. The third switching circuit is connected between the second bus point and the positive terminal of the load circuit.

[0025] In one embodiment, a multi-branch battery control system may include multiple battery packs, each containing multiple batteries. For example... Figure 1 The system includes two battery packs: the first battery pack contains batteries 1 and 2, and the second battery pack contains batteries 3 and 4. The negative terminal of each battery pack is connected to a first busbar via a first switching circuit and a second switching circuit, respectively. The positive terminal of each battery pack is connected to a load circuit via a third switching circuit and a pre-charge circuit, respectively. The connection between the negative terminal of each battery pack and the load can be controlled by switching the first and second switching circuits on and off, and the connection between the positive terminal of each battery pack and the load can be controlled by switching the third switching circuit and the pre-charge circuit on and off.

[0026] In one embodiment, the voltage of each battery pack can be detected. If there is a large voltage difference between different battery packs, the battery pack with the higher voltage can be connected to the load circuit to form a discharge loop by controlling the first, second, and third switching circuits and the pre-charging circuit. This discharges the battery pack until its voltage is similar to that of the other battery packs, preventing contactor sticking. If the voltage difference between different battery packs is small, the voltage of each battery pack can be clamped to the same voltage by controlling the first and second switching circuits, and power can be supplied to each load circuit. This solves the imbalance between different battery pack branches, effectively avoids current surges and sticking caused by large voltage differences between battery pack branches, and improves safety performance.

[0027] In one embodiment, the first switching circuit includes: a first resistor and a first switching transistor; a first terminal of the first switching transistor is connected to the negative terminal of any of the battery packs through the first resistor, and a second terminal of the first switching transistor is connected to the first busbar. Figure 2As shown, the first terminal of the first switch Q1 is connected to the negative terminals of batteries 1 and 2 in the first battery pack through the first resistor R1, and the second terminal of the first switch Q1 is connected to the first bus point N. When the first switch Q1 is turned on, batteries 1 and 2 in the first battery pack are clamped to the same voltage. The first terminal of the fourth switch Q4 is connected to the negative terminals of batteries 3 and 4 in the second battery pack through the fourth resistor R4, and the second terminal of the fourth switch Q4 is connected to the first bus point N. When the fourth switch Q4 is turned on, batteries 3 and 4 in the second battery pack are clamped to the same voltage. If the voltage of the first battery pack is much greater than the voltage of the second battery pack, the first switch circuit connected to the first battery pack can be turned on, and the first battery pack discharges through the load until the voltages of the first and second battery packs are similar. If the voltages of the first and second battery packs are not significantly different, the first switch circuits connected to the first and second battery packs respectively are turned on, and the first and second battery packs simultaneously supply power to the load circuit. In this way, the voltage of different battery packs can be adjusted through the first switching circuit, which can prevent voltage imbalance between different battery packs from causing load problems and prevent the contactor from sticking due to machine failure during operation.

[0028] In one embodiment, the pre-charging circuit includes a second resistor R2 and a fourth switching circuit. The first terminal of the fourth switching circuit is connected to the second bus point via the second resistor R2, and the second terminal of the fourth switching circuit is connected to the negative terminal of the load circuit. Before the load circuit operates normally, controlling the on / off state of the pre-charging circuit controls the connection between the positive terminal of each battery in each battery pack and the load circuit, while simultaneously controlling the connection between the negative terminal of each battery and the load circuit. This forms a discharge loop between the battery, the pre-charging circuit, and the load circuit, allowing the corresponding battery to discharge and pre-charge the controller in the load circuit. This prevents voltage imbalance between different battery packs from causing the load to overheat and potentially cause contactor sticking during operation.

[0029] In one embodiment, the load circuit includes multiple first loads, each of which is a controller load; that is, the first load includes a controller capable of autonomously controlling the start and stop of the first load. The fourth switching circuit includes multiple second switching transistors, the first terminal of any second switching transistor being connected to the second resistor R2, and the second terminal of the second switching transistor being connected to the positive terminal of one of the first loads. See also... Figure 2The load circuit includes first loads such as the main drive motor controller, the auxiliary drive three-in-one controller, the air conditioner, the superstructure, and the battery heating device. Each first load is connected to a second resistor R2 via a second switch transistor. Multiple second switches connected to each first load are connected in parallel. For example, the positive terminal of the main drive motor controller is connected to the second resistor R2 via the second switch transistor Qhc1, the air conditioner via the second switch transistor Qhc2, and the battery heating device via the second switch transistor Qhc3. Some first loads can share a second switch transistor with other first loads. For example, the auxiliary drive three-in-one controller is also connected to the second resistor R2 via the second switch transistor Qhc1. The superstructure and PTC-type power distribution loads are also connected to the second resistor R2 via the second switch transistor Qhc2. Battery heating devices 1 and 2 are both connected to the second resistor R2 via the second switch transistor Qhc3. When any load circuit needs to be pre-charged, the pre-charge circuit can be turned on while the first or second switch circuit is turned on, so that the battery, the pre-charge circuit and the load circuit form a discharge circuit.

[0030] In one embodiment, the third switching circuit includes multiple first control switches, each of which is connected between the second bus point and the positive terminal of one of the first loads. Each first load is connected to the positive terminal of each battery through a first control switch. Alternatively, some first loads can be connected to the second bus point P0 through the same first control switch. After the first load is pre-charged via a pre-charging circuit, the pre-charging circuit is disconnected, and simultaneously the first control switch is closed, forming a circuit between the load and the battery pack via the first control switch. The battery pack then supplies power to the first load, enabling it to operate normally. For example, the main drive motor controller is connected to the second bus point P0 via the first control switch KM1. The auxiliary drive three-in-one controller is connected to the second bus point P0 via the first control switch KM1. The air conditioner, superstructure, and PTC power distribution are connected to the second bus point P0 via the first control switch KM3. The battery heating device is connected to the second bus point P0 via the first control switch KM13.

[0031] In one embodiment, the load circuit includes multiple second loads, which are resistive loads, meaning they cannot be controlled to start or stop autonomously and can only be switched on and off externally. The system also includes a third resistor and a third switch; the first terminal of the third switch is connected to the first bus point via the third resistor, and the second terminal of the third switch is connected to the negative terminal of the second load. For example, a PTC-type power distribution load is connected to the first bus point N via a series-connected third switch Q3 and third resistor R3. A battery heating device 1 is connected to the first bus point N via a series-connected third switch Q5 and third resistor R5. A battery heating device 2 is connected to the first bus point N0 via a series-connected third switch Q6 and third resistor R6. By controlling the on / off state of the third switch, the connection of the corresponding second load to the first bus point N can be controlled, thereby controlling the start and stop of the second load.

[0032] In one embodiment, the second switching circuit includes: a plurality of second control switches, each of which is connected between the negative terminal of any battery in any battery pack and the first busbar. Battery 1 in the first battery pack is connected to the first busbar N via second control switch KM14. Battery 2 in the first battery pack is connected to the first busbar N via second control switch KM15. Battery 3 in the second battery pack is connected to the first busbar N via second control switch KM16. Battery 4 in the second battery pack is connected to the first busbar N via second control switch KM17. If the voltage difference between different batteries in the same battery pack is relatively large, the second control switch connected to the battery with the larger voltage can be closed, and the pre-charging circuit or the third switch circuit can be closed simultaneously, allowing the battery with the larger voltage to discharge through the load until the voltage of all batteries in the battery pack is the same. If the voltage difference between different batteries in the same battery pack is not large, the second control switches connected to each battery in the battery pack can be closed to directly clamp the voltage of each battery in the battery pack to the same voltage.

[0033] In one embodiment, a fuse is also connected between each load circuit and the third switching circuit and the pre-charge circuit to prevent excessive current. For example, Figure 2 When the current in the branch containing fuses FU4-FU9 is too high, the corresponding fuses FU4-FU9 will blow to protect the components in the circuit from damage. Each battery in each battery pack is also connected to a current sensor between itself and the second switching circuit to detect the voltage of the corresponding battery. See also Figure 2Batteries 1-4 are connected to the corresponding first and second switching circuits via current sensors A1-A4. The multi-branch battery control system can also set sampling points in multiple locations, such as PB1-PB4, P1-P4, N1-N4, etc., to sample voltage or current, and then connect the first switching circuit, second switching circuit, pre-charging circuit, and third switching circuit according to the sampled voltage or current.

[0034] In one embodiment, each control switch can be a mechanical switch or contactor, or a switching transistor, such as a bipolar transistor or a MOSFET.

[0035] In one embodiment, the first, second, and third switching transistors can be bipolar transistors, MOSFETs, or IGBTs, preferably IGBTs. Replacing contactors with IGBTs saves space and reduces costs. Using IGBTs integrates current sampling, providing early protection against excessive inrush current in parallel branches. An IGBT pre-charging circuit with overcurrent protection is designed on the battery branch, effectively protecting against current surges during large voltage difference parallel connections between branches. Overcurrent protection is also provided for heating loads; the negative circuit of heating loads uses integrated IGBT overcurrent protection, effectively preventing contactor sticking during load operation and power-on, and preventing contactor sticking caused by machine failure during operation.

[0036] In one embodiment, the multi-branch battery control system includes a fast-charging interface, which is connected to an inductive power transfer (IPT) system. The IPT system is connected to a second busbar P0 via a third control switch KM8 and to a first busbar N via a fourth control switch KM12. In one embodiment, the second busbar P0 is also directly connected to an auxiliary drive three-in-one controller, with the corresponding battery serving as a high-voltage activation power source.

[0037] The multi-branch battery control system of this application embodiment includes: a first switching circuit, including a first input terminal and a first output terminal, the first input terminal being connected to the negative terminal of each battery in any battery pack, and the first output terminal being connected to a first busbar, used for balancing the battery packs when closed, wherein the battery pack includes at least two associated batteries, and the first busbar is the busbar for the negative terminal of each load circuit; a second switching circuit, including multiple second input terminals and a second output terminal, wherein any second input terminal is connected to the negative terminal of any battery in any battery pack, and the second output terminal is connected to the first busbar, used for balancing the batteries in any battery pack when closed; a pre-charging circuit, connected between the second busbar and the positive terminal of the load, wherein the second busbar is the busbar for the positive terminal of each battery; and a third switching circuit, connected between the second busbar and the positive terminal of the load circuit; which can effectively prevent contactor sticking during load operation and power-on, and improve the safety of the multi-branch battery control system.

[0038] Figure 3 The diagram shown is a flowchart illustrating a multi-branch battery control method according to an embodiment of this application. Figure 1 As shown, the multi-branch battery control method includes: Step S11: Detect the voltage difference between any two battery packs.

[0039] Sensors can be installed on each battery branch in each battery pack to detect the voltage of the corresponding battery and further calculate the voltage difference between different battery packs.

[0040] Step S12: If the voltage difference is greater than the reference voltage, control the output voltage of the first battery pack with the larger voltage and discharge it to each load circuit until the voltage difference between the battery packs is less than or equal to the reference voltage.

[0041] If the voltage difference is greater than the reference voltage, the first switch circuit connected to the first battery pack with the higher voltage is closed, and the pre-charge circuit is also closed. The first battery pack with the higher voltage outputs its voltage and pre-charges each load circuit. Then, the second control switch connected to each battery in the first battery pack is closed, so that the voltage between the second bus point p0 and the first bus point N reaches a preset ratio greater than or equal to the voltage between the positive terminal PB1 of the battery and the first bus point N. The preset ratio can be set as needed, preferably 95%, but other values ​​are also possible and are not specifically limited here. After the pre-charge is complete, the first switch circuits connected to each battery pack are simultaneously disconnected, the pre-charge circuit is disconnected, and the third switch circuit is closed, so that each load is powered on and operates normally.

[0042] Step S13: If the voltage difference is less than or equal to the reference voltage, control the voltage of each battery pack to be clamped to the same voltage and supply power to each load circuit.

[0043] The voltage of each battery pack is clamped to the same voltage and then supplied to each load circuit.

[0044] In one embodiment, if the voltage difference is less than or equal to the reference voltage, it indicates that the contactor will not stick. The first switch circuit connected to the negative terminal of the first battery pack can be closed to turn on each battery in the first battery pack to the pre-charging circuit for discharge. Then, the second switch circuit connected to the negative terminal of each battery in the first battery pack is closed to make the voltage between the negative terminal of each battery in the first battery pack and the first busbar close to the voltage between the second busbar and the first busbar.

[0045] Then, the first switching circuit connected to the negative terminal of the second battery pack is closed, clamping the negative terminal voltages of all batteries in the first and second battery packs to the same voltage. Simultaneously, the second switching circuit connected to the negative terminal of each battery in the second battery pack is closed, while the first switching circuits connected to the negative terminals of both the first and second battery packs are opened. After complete pre-charging, the first switching circuits connected to each battery pack are simultaneously disconnected, the pre-charging circuit is opened, and the third switching circuit is closed, powering on all loads and enabling normal operation.

[0046] In one embodiment, if the voltage difference between different batteries in the same battery pack is too large, a similar method can be applied to control the second switch circuit connected to the battery with the larger voltage to close, and at the same time control the corresponding pre-charging circuit to close to pre-charge the load circuit. After the pre-charging is completed, the pre-charging circuit is disconnected and the third switch circuit is closed to supply power to the load so that the load can be powered on and run.

[0047] The following details an example of multi-branch battery control, combined with... Figure 2 ,like Figure 4 As shown, the multi-branch battery control method includes: Step 100: Power on the vehicle key.

[0048] Insert the key into the vehicle and turn it to the "on" position on the ignition switch.

[0049] Step 101: Compare the battery voltages of the two branches: U1 (voltage at points PB1 and PB2) and U2 (voltage at points PB3 and PB4).

[0050] The voltages at the positive electrode sampling points PB1-PB4 of batteries 1-4 are collected. U1 and U2 are obtained based on the collected voltages at each sampling point, where U1 is the voltage between sampling point PB1 and sampling point PB2, and U2 is the voltage between sampling point PB3 and sampling point PB4.

[0051] Step 102: If |U1-U2| ≤ U0.

[0052] Compare voltages U1 and U2, and calculate the voltage difference between them, which represents the voltage difference between the first and second battery packs. Compare the absolute value of this voltage difference with a preset threshold to determine if the absolute value is less than or equal to the preset threshold. If the absolute value is less than or equal to the preset threshold, it can be either the voltage difference between the first and second battery packs is less than or equal to the preset threshold, or the voltage difference between the second and first battery packs is less than or equal to the preset threshold.

[0053] Step 103: Q1 pipe opening.

[0054] When the first switch Q1, which is connected to batteries 1 and 2 in the first battery pack, is closed, the main drive motor controller and the auxiliary drive three-in-one precharge is initiated, and the current direction is from top to bottom through the second resistor R2.

[0055] Step 104: KM14 and KM15 are closed.

[0056] The second control switch KM14, which is connected to battery 1 in the first battery pack, and the second control switch KM15, which is connected to battery 2 in the first battery pack, are closed.

[0057] Step 105: Open Q4 pipe.

[0058] When the fourth switch Q4, which is connected to batteries 3 and 4 in the second battery pack, is closed, the main drive motor controller and the auxiliary drive three-in-one continue to precharge, and the current direction is from top to bottom through the second resistor R2.

[0059] Step 106: KM16 and KM17 are closed.

[0060] The second control switch KM16, which is connected to battery 3 in the second battery pack, and the second control switch KM17, which is connected to battery 4 in the second battery pack, are closed.

[0061] Step 107: Open Qhc1, UP1≥95%UP0 for 100ms, close KM1 for 100ms, and close Qhc1.

[0062] Close the second switch Qhc1. The voltage UP1 at sampling point P1 is greater than or equal to 95% of the voltage UP0 at sampling point P0, and remains so for 100ms. Then, control the first control switch KM1 to close for 100ms, and then control the second switch Qhc1 to open.

[0063] Step 108: Open Qhc2, UP2 ≥ 95%UP0, close KM3 for 100ms, then close Qhc2. Then proceed to step 119.

[0064] Close the second switch Qhc2. If the voltage UP2 at sampling point P2 is greater than or equal to 95% of the voltage UP0 at sampling point P0, control the first control switch KM3 to close and hold for 100ms, then control the second switch Qhc2 to open.

[0065] Step 109: Enter single-branch limp mode.

[0066] If the absolute value of the voltage difference exceeds a preset threshold, the circuit enters single-branch limp mode. This means that only one battery pack is used to power the load circuit.

[0067] Step 110: If |U1-U2| > U0, and U1-U2 > 0.

[0068] Determine whether the absolute value of the voltage difference is greater than a preset threshold, and whether the voltage of the first battery pack is greater than the voltage of the second battery pack (greater than 0).

[0069] Step 111: Q1 pipe opening.

[0070] If the absolute value of the voltage difference is greater than the preset threshold, and the voltage of the first battery pack is greater than the voltage of the second battery pack and greater than 0, then the first switch Q1 connected to battery 1 and battery 2 in the first battery pack is closed, and the main drive motor controller and the auxiliary drive three-in-one precharge is initiated, with the current direction being from top to bottom through the second resistor R2.

[0071] Step 112: KM14 and KM15 are closed.

[0072] The second control switch KM14, which is connected to battery 1 in the first battery pack, and the second control switch KM15, which is connected to battery 2 in the first battery pack, are closed.

[0073] Step 113: Open Qhc1, keep UP1 ≥ 95% UP0 for 100ms, close KM1 for 100ms, and close Qhc1.

[0074] Close the second switch Qhc1. The voltage UP1 at sampling point P1 is greater than or equal to 95% of the voltage UP0 at sampling point P0, and remains so for 100ms. Then, control the first control switch KM1 to close for 100ms, and then control the second switch Qhc1 to open.

[0075] Step 114: Open Qhc2, UP2≥95%UP0, close KM3 for 100ms, then close Qhc2.

[0076] Close the second switch Qhc2. If the voltage UP2 at sampling point P2 is greater than or equal to 95% of the voltage UP0 at sampling point P0, control the first control switch KM3 to close and hold for 100ms, then control the second switch Qhc2 to open.

[0077] If other controller loads also require pre-charging before power-on, the control closes the second switch connected to the corresponding controller load to perform pre-charging. After pre-charging is complete, the control closes the corresponding first control switch and opens the corresponding second switch.

[0078] Step 115: The vehicle is powered on and begins operation. Monitor the branch line pressure difference while driving.

[0079] Once all controller loads have been pre-charged, the vehicle is powered on and each load circuit begins operation. The first battery pack supplies power to each load circuit, and the voltage difference between branches is monitored during driving until the voltage difference between the first battery pack and other battery packs is less than or equal to a preset threshold.

[0080] Step 116: If |U1-U2| ≤ U0.

[0081] Determine whether the absolute value of the voltage difference between the first battery pack and the second battery pack is less than or equal to a preset threshold. If the absolute value of the voltage difference between the first battery pack and the second battery pack is less than or equal to the preset threshold, it indicates that the first battery pack has discharged to a voltage similar to that of the other battery packs.

[0082] Step 117: Q4 tube opening.

[0083] When the fourth switch Q4, which is connected to batteries 3 and 4 in the second battery pack, is closed, the main drive motor controller and the auxiliary drive three-in-one continue to precharge, and the current direction is from top to bottom through the second resistor R2.

[0084] Step 118: KM16 and KM17 are closed.

[0085] The second control switch KM16, which is connected to battery 3 in the second battery pack, and the second control switch KM17, which is connected to battery 4 in the second battery pack, are closed.

[0086] Step 119: Powering on the branch line is complete.

[0087] Power-on of all branches of the vehicle is complete, and all load circuits are operating normally.

[0088] This invention provides a multi-branch battery control method that detects the voltage difference between any two battery packs. If the voltage difference is greater than a reference voltage, the method controls the output voltage of the first battery pack with the larger voltage and discharges it to each load circuit until the voltage difference between the battery packs is less than or equal to the reference voltage. If the voltage difference is less than or equal to the reference voltage, the method controls the voltage of each battery pack to be clamped to the same voltage and supplies power to each load circuit. This effectively prevents contactor sticking during load operation and power-on, improving the safety of the multi-branch battery control system.

[0089] According to another aspect of the present invention, one embodiment of the present invention provides a vehicle including the aforementioned multi-branch battery control system.

[0090] The beneficial effects of the above embodiments can be referred to the beneficial effects of the corresponding methods provided above, and will not be repeated here.

[0091] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0092] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0093] It should also be noted that in the apparatus or equipment of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0094] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0095] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A multi-branch battery control system, characterized in that, The system includes: The first switching circuit includes a first input terminal and a first output terminal. The first input terminal is connected to the negative terminal of each battery in any battery pack, and the first output terminal is connected to a first busbar for balancing the battery packs when closed. The battery pack includes at least two associated batteries, and the first busbar is the busbar for the negative terminal of each load circuit. The second switching circuit includes multiple second input terminals and one second output terminal. Each second input terminal is connected to the negative terminal of any battery in any battery pack, and the second output terminal is connected to the first busbar, which is used to balance the batteries in any battery pack when closed. A pre-charging circuit is connected between the second busbar and the positive terminal of the load circuit, wherein the second busbar is the busbar of the positive terminal of each battery. The third switching circuit is connected between the second bus point and the positive terminal of the load circuit.

2. The system according to claim 1, characterized in that, The first switching circuit includes a first resistor and a first switching transistor; a first terminal of the first switching transistor is connected to the negative terminal of any of the battery packs through the first resistor, and a second terminal of the first switching transistor is connected to the first bus point.

3. The system according to claim 1, characterized in that, The pre-charging circuit includes a second resistor and a fourth switching circuit. The first terminal of the fourth switching circuit is connected to the second bus point through the second resistor, and the second terminal of the fourth switching circuit is connected to the negative terminal of the load circuit.

4. The system according to claim 3, characterized in that, The load circuit includes multiple first loads, the first loads being controller loads; the fourth switching circuit includes multiple second switching transistors, the first end of any second switching transistor being connected to the second resistor, and the second end of the second switching transistor being connected to the positive terminal of one of the first loads.

5. The system according to claim 4, characterized in that, The third switching circuit includes a plurality of first control switches, any one of which is connected between the second bus point and the positive terminal of one of the first loads.

6. The system according to claim 1, characterized in that, The load circuit includes multiple second loads, which are resistive loads; the system also includes a third resistor and a third switch; the first terminal of the third switch is connected to the first bus point through the third resistor, and the second terminal of the third switch is connected to the negative terminal of the second load.

7. The system according to claim 1, characterized in that, The second switching circuit includes: a plurality of second control switches, any one of which is connected between the negative terminal of any of the batteries in any of the battery packs and the first busbar.

8. A multi-branch battery control method, characterized in that, The method, applied to a multi-branch battery control system as described in any one of claims 1-7, comprises: Detect the voltage difference between any two battery packs; If the voltage difference is greater than the reference voltage, the first battery pack with the larger control voltage outputs its voltage and discharges to each load circuit until the voltage difference between the battery packs is less than or equal to the reference voltage. If the voltage difference is less than or equal to the reference voltage, the control clamps the voltage of each battery pack to the same voltage and supplies power to each load circuit.

9. The method according to claim 8, characterized in that, If the voltage difference is less than or equal to the reference voltage, the control will clamp the voltage of each battery pack to the same voltage and control the power-on operation of each load circuit, including: If the voltage difference is less than or equal to the reference voltage, the first switch circuit connected to the negative terminal of the first battery pack is closed, so that each battery in the first battery pack is turned on to the pre-charging circuit for discharge. Then, the second switch circuit connected to the negative terminal of each battery in the first battery pack is closed, so that the voltage between the negative terminal of each battery in the first battery pack and the first busbar is close to the voltage between the second busbar and the first busbar. The first switch circuit connected to the negative terminal of the second battery pack is closed, clamping the negative terminal voltages of each battery in the first and second battery packs to the same voltage; the second switch circuit connected to the negative terminal of each battery in the second battery pack is closed, while the first switch circuit connected to the negative terminal of the first battery pack and the first switch circuit connected to the negative terminal of the second battery pack are opened.

10. A vehicle, characterized in that, The vehicle includes a multi-branch battery control system as described in any one of claims 1-7.

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