Power supply method and device of battery system, vehicle power supply system and vehicle

Abstract

The invention discloses a power supply method and device of a battery system, a vehicle power supply system and a vehicle. The method comprises the steps that a first state parameter of a first power battery and a second state parameter of a second power battery are obtained; according to the first state parameter and the second state parameter, whether the first power battery and the second power battery break down or not is judged; when one of the first power battery and the second power battery breaks down, the first end and the second end of the bidirectional converter are communicated, and the third end and the fourth end of the bidirectional converter are communicated, so that the first power battery and the second power battery are connected in parallel, and the power battery which does not break down supplies power to a load and supplies power to a vehicle. The vehicle is driven to run to a maintenance station or a safe position, the running vehicle is prevented from stopping suddenly, and the driving safety is improved.

Description

Technical Field

[0001] This application belongs to the field of battery management technology, and in particular relates to a power supply method, device, vehicle power supply system and vehicle for a battery system. Background Technology

[0002] In related technologies, most vehicle battery systems consist of a single power battery. When this power battery fails, it cannot continue to supply power to the load (such as the drive motor). For vehicles already in motion, the abnormal power supply from the battery system causes them to lose power and suddenly stop in the middle of the road, increasing driving risks. Furthermore, because the disabled vehicle cannot move, it needs to be towed or pushed to a repair shop, causing significant inconvenience to users. Summary of the Invention

[0003] This application provides a battery system power supply method, device, vehicle power supply system, and vehicle. It can determine whether a fault has occurred based on the state parameters of a first power battery and a second power battery. When one of the first power battery and the second power battery fails, the first and second terminals of the bidirectional converter, as well as the third and fourth terminals of the bidirectional converter, are connected to connect the first power battery and the second power battery in parallel. The power battery that has not failed supplies power to the load and provides power to the vehicle, driving the vehicle to a repair station or a safe location. This prevents the vehicle from stopping suddenly and improves driving safety.

[0004] In a first aspect, embodiments of this application provide a power supply method for a battery system, used to supply power to a vehicle. The battery system includes a first power battery, a second power battery, a bidirectional converter, a first switch, and a second switch. A first terminal of the first power battery is connected to a first end of the bidirectional converter, and a second terminal of the first power battery is connected to a first end of a load. A first terminal of the second power battery is connected to a second end of the load, and a third terminal of the second power battery is connected to a third terminal of the bidirectional converter. The first switch is located on a branch between the first power battery and the load, and the second switch is located on a branch between the second power battery and the load. A second end of the bidirectional converter is connected to a first connection point, and a fourth end of the bidirectional converter is connected to a second connection point. The first connection point is the connection point between the second switch and the load, and the second connection point is the connection point between the first switch and the load. The method includes: Obtain the first state parameters of the first power battery and the second state parameters of the second power battery; Based on the first state parameter and the second state parameter, determine whether the first power battery and the second power battery have malfunctioned. If one of the first and second power batteries fails, disconnect the first and second switches. Connect the first and second terminals of the bidirectional converter, and connect the third and fourth terminals of the bidirectional converter; Close the switch connected to the fault-free power battery, and the fault-free power battery will supply power to the load.

[0005] According to any of the foregoing embodiments of the first aspect of this application, the vehicle includes a drive motor and drive wheels, the drive motor includes a first drive motor and a second drive motor, and correspondingly, before disconnecting the first switch and the second switch, the method further includes: Get the wheel speed; When the wheel speed exceeds the set speed threshold, the drive motor is decoupled from the drive wheel. After closing the switch connected to the fault-free power battery, the method further includes: Control one of the first drive motor and the second drive motor to couple with the corresponding drive wheel.

[0006] According to any of the foregoing embodiments of the first aspect of this application, the battery system further includes a reverse pre-charge type DC-DC converter, wherein a first terminal of the reverse pre-charge type DC-DC converter is connected to a first terminal of the load, a second terminal of the reverse pre-charge type DC-DC converter is connected to a second terminal of the load, and a third terminal of the reverse pre-charge type DC-DC converter is connected to a DC power supply. Accordingly, after disconnecting the first switch and the second switch, the method further includes: The reverse pre-charge type DC-DC converter is controlled to adjust the output voltage of the DC power supply to the first voltage. The state parameters of the power battery that has not experienced a fault include the second voltage. The absolute difference between the first voltage and the second voltage is less than or equal to the second voltage threshold.

[0007] According to any of the foregoing embodiments of the first aspect of this application, before obtaining the first state parameters of the first power battery and the second state parameters of the second power battery, the method further includes: Responding to a wake-up signal, perform a battery system self-test; After the self-test is completed, connect the first and third terminals of the bidirectional converter; Close one of the first and second switches to control the reverse pre-charge type DC-DC converter to perform reverse pre-charge; After confirming that the reverse pre-charge is complete, close the other of the first and second switches; After power-on, confirm that the vehicle is in a ready state.

[0008] According to any of the foregoing embodiments of the first aspect of this application, the method further includes: When neither the first power battery nor the second power battery malfunctions, the first power battery and the second power battery supply power to the load.

[0009] According to any of the foregoing embodiments of the first aspect of this application, when neither the first power battery nor the second power battery malfunctions, power is supplied to the load by the first power battery and the second power battery, including: When neither the first power battery nor the second power battery is faulty, obtain the maximum operating voltage of the load; When the maximum operating voltage is greater than or equal to the third voltage threshold, the first and third terminals of the bidirectional converter are connected. The third voltage threshold is determined based on the third voltage of the first power battery and the fourth voltage of the second power battery. When the first and second switches are closed, the first and second power batteries supply power to the load in series.

[0010] According to any of the foregoing embodiments of the first aspect of this application, when neither the first power battery nor the second power battery malfunctions, the power supply to the load from the first power battery and the second power battery further includes: When the maximum operating voltage is less than the third voltage threshold, connect the first and second terminals of the bidirectional converter, and connect the third and fourth terminals of the bidirectional converter. When the first and second switches are closed, the first and second power batteries supply power to the load in parallel.

[0011] According to any of the foregoing embodiments of the first aspect of this application, the method further includes: When both the first and second power batteries fail, disconnect the first and second switches to power off the entire vehicle.

[0012] According to any of the foregoing embodiments of the first aspect of this application, the method further includes: In response to the power-down command, the first switch and the second switch are disconnected; Connect the first and second ends of the bidirectional converter, or disconnect the connections at each end of the bidirectional converter.

[0013] Secondly, embodiments of this application also provide a power supply device for a battery system, which is used to supply power to a vehicle. The battery system includes a first power battery, a second power battery, a bidirectional converter, a first switch, and a second switch. A first terminal of the first power battery is connected to a first end of the bidirectional converter, and a second terminal of the first power battery is connected to a first end of a load. A first terminal of the second power battery is connected to a second end of the load, and a third terminal of the second power battery is connected to a third terminal of the bidirectional converter. The first switch is located on a branch between the first power battery and the load, and the second switch is located on a branch between the second power battery and the load. A second end of the bidirectional converter is connected to a first connection point, and a fourth end of the bidirectional converter is connected to a second connection point. The first connection point is the connection point between the second switch and the load, and the second connection point is the connection point between the first switch and the load. The device includes: The acquisition module is used to acquire the first state parameters of the first power battery and the second state parameters of the second power battery. The judgment module is used to determine the faulty battery and the number of faulty batteries based on the first state parameter and the second state parameter. The switching module is used to disconnect the first switch and the second switch when one of the first power battery and the second power battery fails. The switching module is also used to connect the first and second terminals of the bidirectional converter, and to connect the third and fourth terminals of the bidirectional converter. The switching module is also used to close the switch connected to the power battery that is not faulty, so that the power battery that is not faulty can supply power to the load.

[0014] Thirdly, embodiments of this application also provide a vehicle power supply system, including: The battery system includes a first power battery, a second power battery, a bidirectional converter, a first switch, and a second switch. The first terminal of the first power battery is connected to the first end of the bidirectional converter, and the second terminal of the first power battery is connected to the first end of a load. The first terminal of the second power battery is connected to the second end of the load, and the second terminal of the second power battery is connected to the third end of the bidirectional converter. The first switch is located on a branch between the first power battery and the load, and the second switch is located on a branch between the second power battery and the load. The second end of the bidirectional converter is connected to a first connection point, and the fourth end of the bidirectional converter is connected to a second connection point. The first connection point is the connection point between the second switch and the load, and the second connection point is the connection point between the first switch and the load. The controller is configured to perform the steps of any of the above-described battery system power supply methods.

[0015] Fourthly, embodiments of this application also provide a vehicle, including the aforementioned vehicle power supply system.

[0016] The battery system power supply method, device, vehicle power supply system, and vehicle provided in this application embodiment can determine whether a fault has occurred based on the state parameters of the first power battery and the second power battery. When one of the first power battery and the second power battery fails, the first and second terminals of the bidirectional converter and the third and fourth terminals of the bidirectional converter are connected to connect the first power battery and the second power battery in parallel. The power battery that has not failed supplies power to the load and provides power to the vehicle, driving the vehicle to a repair station or a safe location, preventing the vehicle from stopping suddenly, and improving driving safety. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a battery system provided in an embodiment of this application; Figure 2 This is a schematic flowchart of a power supply method for a battery system provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application; Figure 4 This is a schematic flowchart of another power supply method for a battery system provided in an embodiment of this application; Figure 5 This is a schematic flowchart of another power supply method for a battery system provided in an embodiment of this application; Figure 6 This is a schematic flowchart of another power supply method for a battery system provided in an embodiment of this application; Figure 7 This is a schematic flowchart of another power supply method for a battery system provided in an embodiment of this application; Figure 8 yes Figure 7 A detailed flowchart of the power supply method S160 for the battery system is shown. Figure 9 This is a schematic diagram of the current flow path of the first power battery failure and the second power battery supply provided in the embodiments of this application; Figure 10 This is a schematic diagram of the current flow path of the first power battery supplying power in the event of a second power battery failure, as provided in an embodiment of this application. Figure 11 This is a schematic diagram of the current flow path of the first power battery and the second power battery connected in series to supply power to the load, as provided in the embodiments of this application. Figure 12 This is a schematic diagram of the current flow path of the first power battery and the second power battery connected in parallel to supply power to the load, according to an embodiment of this application. Figure 13 This is a schematic diagram of the power supply device for a battery system provided in an embodiment of this application. Detailed Implementation

[0019] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0020] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0021] To address the technical problems raised in the background, embodiments of this application provide a battery system power supply method, apparatus, vehicle power supply system, and vehicle. The battery system power supply method provided in this application embodiment will be described first below.

[0022] Figure 1 This is a schematic diagram of the structure of a battery system provided in an embodiment of this application. Figure 2 This is a schematic diagram of another battery system provided in an embodiment of this application. Figure 3 This is a schematic flowchart of a power supply method for a battery system provided in an embodiment of this application.

[0023] like Figure 1 As shown, the battery system includes a first power battery B1, a second power battery B2, a bidirectional converter 1, a first switch K1, and a second switch K2.

[0024] In this configuration, the first terminal of the first power battery B1 is connected to the first terminal a of the bidirectional converter 1, and the second terminal of the first power battery B1 is connected to the first terminal of the load 2; the first terminal of the second power battery B2 is connected to the second terminal of the load 2, and the second terminal of the second power battery B2 is connected to the third terminal c of the bidirectional converter 1. One of the first and second terminals is a positive terminal, and the other is a negative terminal.

[0025] In one example, the difference between the first nominal voltage of the first power battery B1 and the second nominal voltage of the second power battery B2 is less than or equal to a set voltage threshold. For example, the first nominal voltage of the first power battery B1 and the second nominal voltage of the second power battery B2 are equal, both being 400V.

[0026] In one example, the first power battery B1 includes at least one cell, and the second power battery B2 includes at least one cell. The number of cells in the first power battery B1 is equal to the number of cells in the second power battery B2, such that the voltage of the first power battery B1 is equal to the voltage of the second power battery B2.

[0027] The first switch K1 is located on the branch between the first power battery B1 and the load 2, and the second switch K2 is located on the branch between the second power battery B2 and the load 2; the second end b of the bidirectional converter 1 is connected to the first connection point m, and the fourth end d of the bidirectional converter 1 is connected to the second connection point n. The first connection point m is the connection point between the second switch K2 and the load 2, and the second connection point n is the connection point between the first switch K1 and the load 2.

[0028] The first switch K1 and the second switch K2 may include all types of electronic devices with switching functions known to those skilled in the art, such as relays, contactors or single-pole switches, without limitation herein.

[0029] In one example, the bidirectional converter 1 may include a power interface and a signal interface. The power interface is used to connect to an external power supply to power the circuitry of the bidirectional converter 1, and the signal interface is used to receive control signals. In response to the received control signals, the bidirectional converter 1 switches the connectivity of each terminal.

[0030] like Figure 2 As shown, the power supply method of the battery system provided in this application embodiment is used to supply power to a vehicle. The method may include the following steps: S110~S150.

[0031] S110: Obtain the first state parameters of the first power battery and the second state parameters of the second power battery.

[0032] The first dynamic state parameter may include at least one of the following: operating current, operating voltage, operating power, and operating temperature; the second state parameter may include at least one of the following: operating current, operating voltage, operating power, and operating temperature.

[0033] S120. Based on the first state parameter and the second state parameter, determine whether the first power battery and the second power battery have malfunctioned.

[0034] In this step, the first state parameter is compared with the corresponding set threshold to determine whether the first power battery B1 has malfunctioned, and the second state parameter is compared with the corresponding set threshold to determine whether the second power battery B2 has malfunctioned, thereby determining the number of faulty batteries. When either the first power battery or the second power battery malfunctions, i.e., the number of faulty batteries is 1, step S130 is executed.

[0035] S130. When one of the first power battery and the second power battery fails, disconnect the first switch and the second switch.

[0036] In this step, when one of the first power battery B1 and the second power battery B2 fails, the first switch K1 and the second switch K2 are disconnected, cutting off the power supply circuit between the power battery and the load 2.

[0037] S140 connects the first and second terminals of the bidirectional converter, and connects the third and fourth terminals of the bidirectional converter.

[0038] In this step, the bidirectional converter 1 is switched to parallel mode, connecting the first and second terminals of the bidirectional converter, as well as the third and fourth terminals of the bidirectional converter, so that the first power battery B1 and the second power battery B2 are connected in parallel.

[0039] S150: Close the switch connected to the power battery that is not faulty, and supply power to the load from the power battery that is not faulty.

[0040] Load 2 may include all high-voltage platform components on the vehicle, such as drive motors.

[0041] In this step, if the first power battery B1 malfunctions but the second power battery B2 does not malfunction, then the second switch K2 is closed, and the second power battery B2 supplies power to the load 2. If the second power battery B2 malfunctions but the first power battery B1 does not malfunction, then the first switch K1 is closed, and the first power battery B1 supplies power to the load 2.

[0042] For example, such as Figure 9 As shown, when the first power battery B1 malfunctions, the first terminal a and the second terminal b of the bidirectional converter 1, as well as the third terminal c and the fourth terminal d of the bidirectional converter 1, are connected, causing the first power battery B1 and the second power battery B2 to be connected in parallel. The second switch K2 is closed, but the first switch K1 is not closed. The second power battery B2 supplies power to the load, and the current flow path is as follows. Figure 9 As indicated by the black solid arrow in the middle.

[0043] For example, such as Figure 10As shown, when the second power battery B2 malfunctions, the first terminal a and the second terminal b of the bidirectional converter 1 are connected, as are the third terminal c and the fourth terminal d of the bidirectional converter 1, causing the first power battery B1 and the second power battery B2 to be connected in parallel. The first switch K1 is closed, but the second switch K2 is not closed. The first power battery B1 supplies power to the load, and the current flow path is as follows. Figure 10 As indicated by the black solid arrow in the middle.

[0044] The battery system power supply method of this application embodiment is used to power a vehicle. The battery system includes a first power battery B1, a second power battery B2, a bidirectional converter 1, a first switch K1, and a second switch K2. The first terminal of the first power battery B1 is connected to the first terminal a of the bidirectional converter 1, and the second terminal of the first power battery B1 is connected to the first terminal of a load 2. The first terminal of the second power battery B2 is connected to the second terminal of the load 2, and the second terminal of the second power battery B2 is connected to the third terminal c of the bidirectional converter 1. The first switch K1 is located on the branch between the first power battery B1 and the load 2, and the second switch K2 is located on the branch between the second power battery B2 and the load 2. The second terminal b of the bidirectional converter 1 is connected to a first connection point m, and the fourth terminal d of the bidirectional converter 1 is connected to a second connection point n. The first connection point m is the connection point between the second switch K2 and the load 2, and the second connection point n is the connection point between the first switch K1 and the load 2. This method can determine whether a fault has occurred based on the state parameters of the first power battery B1 and the second power battery B2. When one of the first power battery B1 and the second power battery B2 fails, the first terminal a and the second terminal b of the bidirectional converter 1, as well as the third terminal c and the fourth terminal d of the bidirectional converter 1, are connected to connect the first power battery B1 and the second power battery B2 in parallel. The power battery that has not failed supplies power to the load 2, provides power to the vehicle, and drives the vehicle to a repair station or a safe location, preventing the vehicle from stopping suddenly and improving driving safety.

[0045] In one embodiment, such as Figure 3 As shown, the vehicle includes a drive motor 101 and drive wheels 102. The drive motor includes a first drive motor and a second drive motor. One of the first drive motor and the second drive motor is a front drive motor, and the other is a rear drive motor. The power battery supplies power to the drive motor 101, providing it with a power source. The drive motor drives the drive wheels to rotate, thereby driving the vehicle.

[0046] Accordingly, such as Figure 4 As shown, before S134 "disconnecting the first switch and the second switch", the method may further include the following steps: S132~S133.

[0047] S132, Obtain the wheel speed.

[0048] If a fault is detected in either the first power battery B1 or the second power battery B2, the wheel speed can be obtained using a wheel speed sensor. This application does not limit the type of wheel speed sensor; any wheel speed sensor known to those skilled in the art can be used, such as a Hall effect wheel speed sensor or a magnetoelectric wheel speed sensor.

[0049] In one example, the vehicle's speed can also be determined based on the wheel rotation speed and wheel circumference.

[0050] S133. When the wheel speed is greater than the set speed threshold, control the drive motor to decouple from the drive wheel.

[0051] When the wheel speed is greater than the set speed threshold, it indicates that the vehicle is traveling at a high speed. If the first switch K1 and the second switch K2 are disconnected at this time, the power supply circuit will be cut off. A large back electromotive force will be generated at the moment of disconnection. The voltage of the back electromotive force is positively correlated with the vehicle's speed. An excessive back electromotive force may damage the circuit components and even affect the vehicle control system.

[0052] This step involves decoupling the drive motor from the drive wheels when the wheel speed exceeds a set speed threshold, thus eliminating the impact of excessive back electromotive force on the vehicle control system. For example... Figure 3 As shown, the vehicle also includes a front and rear wheel-end decoupling mechanism. This step utilizes the front and rear wheel-end structural mechanism to cut off the transmission path between the front drive motor and the front drive wheels, as well as the transmission path between the rear drive motor and the rear drive wheels. The front and rear wheel-end decoupling mechanism may include a mechanical decoupling mechanism or an electronic control decoupling mechanism.

[0053] After S151 “closing the switch connected to the power battery that is not faulty”, the method may further include the following step: S152.

[0054] S152, Control one of the first drive motor and the second drive motor to couple with the corresponding drive wheel.

[0055] In this step, after closing the switch connected to the non-faulty power battery, the power supply circuit between the non-faulty power battery and load 2 is completed, and the non-faulty power battery can supply power to load 2. Before supplying power, the first drive motor is coupled to the corresponding drive wheel, or the second drive motor is coupled to the corresponding drive wheel, so that the vehicle can drive in two-wheel drive mode. This helps to reduce power consumption and ensures that the power of a single power battery can sustain the vehicle to a repair station or a safe location, preventing the vehicle from stopping suddenly and improving driving safety.

[0056] It should be noted that, Figure 4The power supply method of the battery system shown includes steps S110, S120, S131, S134, S140, S151 and S152 which are the same as S110~S150. For details, please refer to the explanation of S110~S150 above, and will not be repeated here.

[0057] The power supply method of the battery system in this application embodiment controls the decoupling of the drive motor and drive wheels when the vehicle is traveling at a high speed, eliminating the influence of excessive back electromotive force on the vehicle control system. After the power supply circuit between the power battery that has not failed and the load 2 is connected, the vehicle is controlled to travel in two-wheel drive mode, so that the power of a single power battery can sustain the vehicle to a repair station or a safe location, preventing the vehicle from stopping suddenly, which is beneficial to improving driving safety.

[0058] In one embodiment, such as Figure 1 As shown, the battery system also includes a reverse pre-charge DC-DC converter 41. The first end of the reverse pre-charge DC-DC converter 41 is connected to the first end of the load 2, the second end of the reverse pre-charge DC-DC converter 41 is connected to the second end of the load 2, and the third end of the reverse pre-charge DC-DC converter 41 is connected to the DC power supply 5.

[0059] The reverse pre-charge DC-DC converter 41 has bidirectional conversion functionality. In reverse pre-charge mode, electrical energy is pre-charged from the low-voltage side (i.e., DC power supply 5) to the equivalent capacitance (i.e., the first capacitor 31) of the electrical equipment on the high-voltage side, inverting the low-voltage electricity into high-voltage electricity to achieve pre-charging of the high-voltage circuit. The reverse pre-charge DC-DC converter 41 also has a forward power supply mode, which can convert the high-voltage electricity of the power battery into low-voltage electricity to charge the DC power supply 5. In one example, the DC power supply 5 may include a 12V / 48V lithium battery.

[0060] Accordingly, such as Figure 5 As shown, after S134 "disconnecting the first switch and the second switch", the method may further include the following step: S135.

[0061] S135 controls the reverse precharge type DC-DC (DCDC) converter to regulate the output voltage of the DC power supply to the first voltage.

[0062] Among them, the state parameters of the power battery that has not experienced a fault include a second voltage, and the absolute difference between the first voltage and the second voltage is less than or equal to the second voltage threshold. For example, the value range of the second voltage threshold is [10V, 20V].

[0063] In this embodiment, after the first switch K1 and the second switch K2 are opened, the power supply circuit of the power battery is cut off. The reverse pre-charge type DC-DC converter 41 adjusts the output voltage of the DC power supply 5 to a first voltage, which is close to the second voltage of the fault-free power battery. This can temporarily maintain the power supply to the vehicle's low-voltage system (such as steering, brake assist, and instrument panel), preventing the low-voltage load from failing due to power supply interruption and ensuring the vehicle's basic functions and safety control requirements. In addition, when the switch connected to the fault-free power battery is closed, a momentary current is generated. The voltage difference between the first voltage and the second voltage is small, preventing the switch contacts from melting and sticking due to excessive voltage difference.

[0064] In one embodiment, such as Figure 6 As shown, before S110 "obtaining the first state parameters of the first power battery and the second state parameters of the second power battery", the method may further include the following steps: S101~S105.

[0065] S101, Perform a battery system self-test in response to the wake-up signal.

[0066] In this step, when the user presses the unlock button on the key, opens the door, or presses the start button, a wake-up signal is forwarded to the vehicle controller via the gateway, waking it up. The vehicle controller then wakes up the battery management system and battery control unit, among other control modules. Once awakened, the battery management system begins a self-test, checking the voltage, differential voltage, temperature, and connection status of the power battery. It also checks the high-voltage interlock, insulation resistance, and the status of the first and second switches, and performs tests on the battery management system's own hardware (such as the control chip, communication interface, and data acquisition module).

[0067] S102. After the self-test is completed, connect the first and third terminals of the bidirectional converter.

[0068] After confirming that the self-test is normal, connect the first terminal a and the third terminal c of the bidirectional converter 1 to connect the first power battery B1 and the second power battery B2 in series.

[0069] S103: Close one of the first and second switches to control the reverse precharge type DC-DC (DCDC) converter to perform reverse precharge.

[0070] In this step, one of the first switch K1 and the second switch K2 is closed, and the bus capacitor (i.e. the first capacitor 31) in the motor controller is reverse precharged using the reverse precharge type DC-DC converter 41.

[0071] S104. After confirming that the reverse pre-charge is complete, close the other of the first and second switches.

[0072] When the pre-charge voltage of the first capacitor 31 reaches a set voltage threshold, it is determined that reverse pre-charging has been completed. For example, the set voltage threshold is greater than or equal to 80% to 90% of the total voltage of the power battery.

[0073] In this step, after completing the reverse pre-charge, the other of the first switch K1 and the second switch K2 is closed, thus connecting the power supply circuit of the power battery. If the first switch K1 is closed by S103, then the second switch K2 is closed in this step. If the second switch K2 is closed by S103, then the first switch K1 is closed in this step.

[0074] S105. After power-on, confirm that the vehicle is in a ready state.

[0075] Once the power supply circuit of the power battery is connected and the high voltage is successfully powered on, the user can be notified by the instrument display or by the illumination of indicator lights, indicating that the vehicle has entered a ready state and can be driven normally.

[0076] The battery system power supply method provided in this embodiment performs a self-test on the battery system before driving, and performs reverse pre-charging and high-voltage power-on after the self-test passes, eliminating safety hazards, avoiding loss of control of the vehicle due to system failure during driving, improving the reliability of vehicle functions, and helping to reduce safety risks.

[0077] In one embodiment, such as Figure 7 As shown, the method may further include the following step: S160.

[0078] S160. When neither the first power battery nor the second power battery is faulty, the first power battery and the second power battery supply power to the load.

[0079] In this embodiment, neither the first power battery B1 nor the second power battery B2 is faulty, meaning there are zero faulty batteries, and both can simultaneously supply power to the load 2. The first power battery B1 and the second power battery B2 can supply power to the load 2 in parallel or series mode, and the connection method can be switched according to the maximum operating voltage of the load 2. For example, when the load 2 is an 800V high-voltage platform component, the first power battery B1 and the second power battery B2 supply power to the load 2 in series mode; when the load 2 is a 400V high-voltage platform component, the first power battery B1 and the second power battery B2 supply power to the load 2 in parallel mode. This method is applicable to loads with different high-voltage platforms, offering high flexibility and versatility.

[0080] In one embodiment, S160 may include the following steps: S161~S163, as follows: Figure 8 As shown.

[0081] S161. When neither the first power battery nor the second power battery has failed, obtain the maximum operating voltage of the load.

[0082] The operating voltage of load 2 is usually a voltage range, for example, the operating voltage range of the load is 200V~900V, and the maximum operating voltage of the load is 900V.

[0083] S162. When the maximum operating voltage is greater than or equal to the third voltage threshold, connect the first and third terminals of the bidirectional converter.

[0084] The third voltage threshold is determined based on the third voltage of the first power battery and the fourth voltage of the second power battery. For example, if the maximum supply voltage (i.e., the third voltage) of the first power battery B1 is 400V and the maximum supply voltage (i.e., the fourth voltage) of the second power battery B2 is 400V, then the range of the third voltage threshold is [750V, 850V].

[0085] In this step, the maximum operating voltage of load 2 is greater than or equal to the third voltage threshold. Connect the first terminal a and the third terminal c of the bidirectional converter 1. After connecting the first power battery B1 and the second power battery B2 in series, the power supply voltage output by the two power batteries will not exceed the maximum operating voltage of load 2, and load 2 will not be overloaded.

[0086] S163. Close the first switch and the second switch, and the first power battery and the second power battery supply power to the load in series.

[0087] In this step, the first switch K1 and the second switch K2 are closed to connect the power supply circuit between the power battery and the load 2. The first power battery B1 and the second power battery B2 supply power to the load in series.

[0088] For example, load 2 is an 800V high-voltage platform component with a maximum operating voltage of 900V. The maximum supply voltage of the first power battery B1 and the second power battery B2 is 400V. The first power battery B1 and the second power battery B2 are connected in series, and the first power battery B1 and the second power battery B2 supply power to load 2 in series.

[0089] For example, such as Figure 11 As shown, neither the first power battery B1 nor the second power battery B2 is faulty. Connecting the first terminal a and the third terminal c of the bidirectional converter 1 connects the first power battery B1 and the second power battery B2 in parallel. Closing the first switch K1 and the second switch K2 allows the first power battery B1 and the second power battery B2 to supply power to the load 2 in series. The current flow path is as follows. Figure 11 As indicated by the black solid arrow in the middle.

[0090] In one embodiment, S160 may further include the following steps: S164~S165, such as... Figure 8 As shown.

[0091] S164. When the maximum operating voltage is less than the third voltage threshold, connect the first and second terminals of the bidirectional converter, and connect the third and fourth terminals of the bidirectional converter.

[0092] In this step, the maximum operating voltage of load 2 is less than the third voltage threshold. If the first power battery B1 and the second power battery B2 are connected in series, the supply voltage output by the two power batteries will be greater than the maximum operating voltage of load 2, posing a significant risk of overload to load 2. Therefore, by connecting the first terminal a and the second terminal b of the bidirectional converter 1, and connecting the third terminal c and the fourth terminal d of the bidirectional converter 1, the first power battery B1 and the second power battery B2 are connected in parallel. The supply voltage output by the two power batteries will not exceed the maximum operating voltage of load 2, and load 2 will not operate under overload.

[0093] S165. Close the first switch and the second switch, and the first power battery and the second power battery supply power to the load in parallel.

[0094] In this step, the first switch K1 and the second switch K2 are closed to connect the power supply circuit between the power battery and the load 2. The first power battery B1 and the second power battery B2 supply power to the load in parallel.

[0095] For example, load 2 is a 400V high-voltage platform component with a maximum operating voltage of 500V. The maximum supply voltage of the first power battery B1 and the second power battery B2 is 400V. The first power battery B1 and the second power battery B2 are connected in parallel, and the first power battery B1 and the second power battery B2 supply power to load 2 in parallel.

[0096] For example, such as Figure 12 As shown, neither the first power battery B1 nor the second power battery B2 malfunctions. Connecting the first terminal a and the second terminal b of the bidirectional converter 1, and connecting the third terminal c and the fourth terminal d of the bidirectional converter 1, connects the first power battery B1 and the second power battery B2 in parallel. Closing the first switch K1 and the second switch K2 allows the first power battery B1 and the second power battery B2 to supply power to the load 2 in parallel. The current flow path is as follows. Figure 12 As indicated by the black solid arrow in the middle.

[0097] In one embodiment, such as Figure 7 As shown, the method may further include the following step: S170.

[0098] S170: When both the first and second power batteries fail, disconnect the first and second switches to power off the entire vehicle.

[0099] In this embodiment, when both the first power battery B1 and the second power battery B2 fail, that is, when there are two faulty batteries, neither power battery can supply power to the load 2, the first switch K1 and the second switch K2 are disconnected, and the entire vehicle is powered off.

[0100] In one embodiment, the method may further include the following steps: In response to the power-down command, the first switch and the second switch are disconnected; Connect the first and second ends of the bidirectional converter, or disconnect the connections at each end of the bidirectional converter.

[0101] In this embodiment, when the vehicle is not working, i.e. in the power-off state, the first terminal a and the second terminal b of the bidirectional converter 1 are connected to connect the first power battery B1 and the second power battery B2 in series, or the connection between each terminal of the bidirectional converter 1 is disconnected to prevent the load 2 from being connected to the positive or negative terminal of the power battery when the power is off, which helps to reduce safety risks.

[0102] In one example, such as Figure 1 As shown, the battery system also includes a current acquisition unit 7, a first protection module 81, and a second protection module 82.

[0103] The current acquisition device 7 is located at least one of the following branches: the branch between the negative terminal of the first power battery B1 and the first switch K1; the branch between the second connection point n and the load; and the branch between the third terminal c of the bidirectional converter 1 and the second power battery B2. The current acquisition device 7 includes all electronic devices with current acquisition functions known to those skilled in the art, such as current sensors or shunts, and is not limited thereto.

[0104] The first protection module 81 is located on the branch between the positive terminal of the first power battery B1 and the bidirectional converter 1. The second protection module 82 is located on the branch between the positive terminal of the second power battery B2 and the second switch K2. The first protection module 81 and the second protection module 82 may include all electronic devices with electrical protection functions known to those skilled in the art, such as fuses, smart fuses, and circuit breakers, and are not limited herein.

[0105] The first protection module 81 is connected in series with the first power battery B1, and the second protection module 82 is connected in series with the second power battery B2. By associating them with the corresponding sensors, protection against overcurrent, overvoltage, or overtemperature in the high-voltage circuit can be achieved.

[0106] For example, such as Figure 1As shown, the first protection module 81 and the second protection module 82 are smart fuses. The first protection module 81 is connected to the positive terminal of the first power battery B1, and the second protection module 82 is connected to the positive terminal of the second power battery B2. When the circuit is overloaded / short-circuited and the fuse blows, the connection between the positive terminal and the subsequent circuit (such as the load or wiring harness) will be completely cut off. There will be no voltage in the subsequent circuit, and there will be no risk of electric shock during maintenance or handling.

[0107] For example, such as Figure 1 As shown, the first protection module 81 and the current collector 7 located in the branch between the negative terminal of the first power battery B1 and the first switch K1 realize overcurrent protection for the first power battery B1; the second protection module 82 and the current collector 7 located in the branch between the third terminal c of the bidirectional converter 1 and the second power battery B2 realize overcurrent protection for the second power battery B2.

[0108] Based on the power supply method for the battery system provided in the above embodiments, this application also provides a specific implementation of a power supply device for the battery system, which is used to supply power to a vehicle. Please refer to the following embodiments.

[0109] First see Figure 13 The power supply device 200 for the battery system provided in this application embodiment includes the following modules: acquisition module 201, judgment module 202 and switching module 203.

[0110] The acquisition module 201 is used to acquire the first state parameters of the first power battery and the second state parameters of the second power battery.

[0111] The judgment module 202 is used to determine whether the first power battery and the second power battery have malfunctioned based on the first state parameter and the second state parameter.

[0112] The switching module 203 is used to disconnect the first switch and the second switch when one of the first power battery and the second power battery fails. The switching module 203 is also used to connect the first and second ends of the bidirectional converter, and to connect the third and fourth ends of the bidirectional converter.

[0113] The switching module 203 is also used to close the switch connected to the power battery that is not faulty, so that the power battery that is not faulty can supply power to the load.

[0114] The power supply device of the battery system provided in this application embodiment can determine whether a fault has occurred based on the state parameters of the first power battery and the second power battery. When one of the first power battery and the second power battery fails, the first and second terminals of the bidirectional converter and the third and fourth terminals of the bidirectional converter are connected to connect the first power battery and the second power battery in parallel. The power battery that has not failed supplies power to the load and provides power to the vehicle, driving the vehicle to a repair station or a safe location, preventing the vehicle from stopping suddenly, and thus improving driving safety.

[0115] In one embodiment, the vehicle includes a drive motor and drive wheels. The drive motor includes a first drive motor and a second drive motor. Accordingly, the device further includes a decoupling module, which is configured to: acquire the wheel speed before disconnecting the first and second switches; control the drive motor to decouple from the drive wheel when the wheel speed is greater than a set speed threshold; and the decoupling module is further configured to: control one of the first and second drive motors to couple with the corresponding drive wheel after closing the switch connected to the power battery that has not failed.

[0116] In one embodiment, the battery system further includes a reverse pre-charge DC-DC converter, a first terminal of which is connected to a first terminal of a load, a second terminal of which is connected to a second terminal of the load, and a third terminal of which is connected to a DC power supply. Accordingly, the device further includes an adjustment module, which is used to: after the first switch and the second switch are disconnected, control the reverse pre-charge DC-DC converter to adjust the output voltage of the DC power supply to a first voltage. The state parameters of the power battery without faults include a second voltage, and the absolute difference between the first voltage and the second voltage is less than or equal to a second voltage threshold.

[0117] In one embodiment, the device further includes a high-voltage power-on module, which is configured to: perform a battery system self-test in response to a wake-up signal before acquiring the first state parameters of the first power battery and the second state parameters of the second power battery; after the self-test is completed, connect the first and third terminals of the bidirectional converter; close one of the first and second switches to control the reverse pre-charge type DC-DC converter to perform reverse pre-charge; after determining that the reverse pre-charge is completed, close the other of the first and second switches; and after power-on is completed, determine that the vehicle has entered a ready state.

[0118] In one embodiment, the switching module is further configured to: supply power to the load from the first power battery and the second power battery when neither of the first power battery nor the second power battery fails.

[0119] In one embodiment, the switching module is further configured to: obtain the maximum operating voltage of the load when neither the first power battery nor the second power battery is faulty; connect the first and third terminals of the bidirectional converter when the maximum operating voltage is greater than or equal to a third voltage threshold, the third voltage threshold being determined based on the third voltage of the first power battery and the fourth voltage of the second power battery; and close the first and second switches, so that the first power battery and the second power battery supply power to the load in series.

[0120] In one embodiment, the switching module is further configured to: connect the first and second terminals of the bidirectional converter, and connect the third and fourth terminals of the bidirectional converter, when the maximum operating voltage is less than a third voltage threshold; close the first and second switches, and the first and second power batteries supply power to the load in parallel.

[0121] In one embodiment, the switching module is further configured to: disconnect the first switch and the second switch to control the vehicle to power down when both the first power battery and the second power battery fail.

[0122] In one embodiment, the switching module is further configured to: disconnect the first switch and the second switch in response to a power-down command; connect the first and second terminals of the bidirectional converter, or disconnect the connection of each terminal in the bidirectional converter.

[0123] Based on the power supply method for the battery system provided in the above embodiments, this application also provides a specific implementation of a vehicle power supply system. Please refer to the following embodiments.

[0124] The vehicle power supply system provided in this application includes a battery system and a controller.

[0125] Among them, such as Figure 1 As shown, the battery system includes a first power battery B1, a second power battery B2, a bidirectional converter 1, a first switch K1, and a second switch K2. The first terminal of the first power battery B1 is connected to the first terminal a of the bidirectional converter 1, and the second terminal of the first power battery B1 is connected to the first terminal of the load 2. The first terminal of the second power battery B2 is connected to the second terminal of the load 2, and the second terminal of the second power battery B2 is connected to the third terminal c of the bidirectional converter 1. The first switch K1 is located on the branch between the first power battery B1 and the load 2, and the second switch K2 is located on the branch between the second power battery B2 and the load 2. The second terminal b of the bidirectional converter 1 is connected to the first connection point m, and the fourth terminal d of the bidirectional converter is connected to the second connection point n. The first connection point m is the connection point between the second switch K2 and the load 2, and the second connection point n is the connection point between the first switch K1 and the load 2.

[0126] The controller is configured to perform the steps of any of the above-described battery system power supply methods, which have corresponding beneficial effects. To avoid repetition, these will not be elaborated further here.

[0127] Based on the above embodiments, this application also provides a vehicle, which includes the above-described vehicle power supply system and has corresponding beneficial effects. To avoid repetition, these will not be described again here.

[0128] The vehicles may include pure electric vehicles or hybrid vehicles, and are not limited to these.

[0129] In other embodiments, the vehicle may also include all components known to those skilled in the art, such as a vehicle controller and a battery management system, which are not limited herein.

[0130] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0131] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by special-purpose hardware performing the specified functions or actions, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0132] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A power supply method for a battery system, characterized in that, The method is used to power a vehicle. The battery system includes a first power battery, a second power battery, a bidirectional converter, a first switch, and a second switch. A first terminal of the first power battery is connected to a first end of the bidirectional converter, and a second terminal of the first power battery is connected to a first end of a load. A first terminal of the second power battery is connected to a second end of the load, and a second terminal of the second power battery is connected to a third end of the bidirectional converter. The first switch is located on a branch between the first power battery and the load, and the second switch is located on a branch between the second power battery and the load. A second end of the bidirectional converter is connected to a first connection point, and a fourth end of the bidirectional converter is connected to a second connection point. The first connection point is the connection point between the second switch and the load, and the second connection point is the connection point between the first switch and the load. The method includes: Obtain the first state parameters of the first power battery and the second state parameters of the second power battery; Based on the first state parameter and the second state parameter, determine whether the first power battery and the second power battery have malfunctioned; If one of the first power battery and the second power battery fails, disconnect the first switch and the second switch; Connect the first and second terminals of the bidirectional converter, and connect the third and fourth terminals of the bidirectional converter; Close the switch connected to the fault-free power battery, and the fault-free power battery supplies power to the load.

2. The power supply method according to claim 1, characterized in that, The vehicle includes a drive motor and drive wheels, the drive motor includes a first drive motor and a second drive motor, and correspondingly, before disconnecting the first switch and the second switch, the method further includes: Get the wheel speed; When the wheel speed exceeds a set speed threshold, the drive motor is decoupled from the drive wheel. After closing the switch connected to the fault-free power battery, the method further includes: Control one of the first drive motor and the second drive motor to couple with the corresponding drive wheel.

3. The power supply method according to claim 1 or 2, characterized in that, The battery system further includes a reverse pre-charge DC-DC converter, wherein a first terminal of the reverse pre-charge DC-DC converter is connected to a first terminal of the load, a second terminal of the reverse pre-charge DC-DC converter is connected to a second terminal of the load, and a third terminal of the reverse pre-charge DC-DC converter is connected to a DC power supply. Correspondingly, after disconnecting the first switch and the second switch, the method further includes: The reverse pre-charge type DC-DC converter is controlled to adjust the output voltage of the DC power supply to a first voltage. The state parameters of the power battery that has not experienced a fault include a second voltage. The absolute difference between the first voltage and the second voltage is less than or equal to a second voltage threshold.

4. The power supply method according to claim 3, characterized in that, Before obtaining the first state parameters of the first power battery and the second state parameters of the second power battery, the method further includes: Responding to a wake-up signal, perform a battery system self-test; After the self-test is completed, connect the first and third terminals of the bidirectional converter; By closing one of the first switch and the second switch, the reverse pre-charge type DC-DC converter is controlled to perform reverse pre-charge; After confirming that the reverse pre-charge is complete, close the other of the first and second switches; After power-on, confirm that the vehicle is in a ready state.

5. The power supply method according to claim 1, characterized in that, The method further includes: When neither the first power battery nor the second power battery malfunctions, the first power battery and the second power battery supply power to the load.

6. The power supply method according to claim 5, characterized in that, When neither the first power battery nor the second power battery malfunctions, the power supply to the load by the first power battery and the second power battery includes: When neither the first power battery nor the second power battery is faulty, obtain the maximum operating voltage of the load; When the maximum operating voltage is greater than or equal to the third voltage threshold, the first and third terminals of the bidirectional converter are connected, wherein the third voltage threshold is determined based on the third voltage of the first power battery and the fourth voltage of the second power battery. When the first switch and the second switch are closed, the first power battery and the second power battery supply power to the load in series.

7. The power supply method according to claim 6, characterized in that, The provision of supplying power to the load by the first and second power batteries when neither the first nor the second power battery malfunctions further includes: When the maximum operating voltage is less than the third voltage threshold, the first and second terminals of the bidirectional converter are connected, as are the third and fourth terminals of the bidirectional converter. When the first switch and the second switch are closed, the first power battery and the second power battery supply power to the load in parallel.

8. The power supply method according to claim 1, characterized in that, The method further includes: When both the first power battery and the second power battery fail, disconnect the first switch and the second switch to power off the entire vehicle.

9. The power supply method according to claim 1, characterized in that, The method further includes: In response to a power-down command, the first switch and the second switch are disconnected; Connect the first and second ends of the bidirectional converter, or disconnect the connections of each end of the bidirectional converter.

10. A power supply device for a battery system, characterized in that, The device is used to power a vehicle. The battery system includes a first power battery, a second power battery, a bidirectional converter, a first switch, and a second switch. A first terminal of the first power battery is connected to a first end of the bidirectional converter, and a second terminal of the first power battery is connected to a first end of a load. A first terminal of the second power battery is connected to a second end of the load, and a second terminal of the second power battery is connected to a third end of the bidirectional converter. The first switch is located on a branch between the first power battery and the load, and the second switch is located on a branch between the second power battery and the load. A second end of the bidirectional converter is connected to a first connection point, and a fourth end of the bidirectional converter is connected to a second connection point. The first connection point is the connection point between the second switch and the load, and the second connection point is the connection point between the first switch and the load. The device includes: The acquisition module is used to acquire the first state parameters of the first power battery and the second state parameters of the second power battery. The judgment module is used to determine whether the first power battery and the second power battery have malfunctioned based on the first state parameter and the second state parameter. A switching module is used to disconnect the first switch and the second switch when one of the first power battery and the second power battery fails; The switching module is also used to connect the first and second ends of the bidirectional converter, and to connect the third and fourth ends of the bidirectional converter. The switching module is also used to close the switch connected to the power battery that is not faulty, so that the power battery that is not faulty can supply power to the load.

11. A vehicle power supply system, characterized in that, include: A battery system includes a first power battery, a second power battery, a bidirectional converter, a first switch, and a second switch. A first terminal of the first power battery is connected to a first end of the bidirectional converter, and a second terminal of the first power battery is connected to a first end of a load. A first terminal of the second power battery is connected to a second end of the load, and a third terminal of the second power battery is connected to a third end of the bidirectional converter. The first switch is located on a branch between the first power battery and the load, and the second switch is located on a branch between the second power battery and the load. A second end of the bidirectional converter is connected to a first connection point, and a fourth end of the bidirectional converter is connected to a second connection point. The first connection point is the connection point between the second switch and the load, and the second connection point is the connection point between the first switch and the load. A controller configured to perform the steps of the power supply method for the battery system as described in any one of claims 1-9.

12. A vehicle, characterized in that, include: The vehicle power supply system as described in claim 11.

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