Battery management system and method for vehicle, and vehicle

Abstract

The present invention provides a battery management system for a vehicle, comprising a high-voltage battery pack, a low-voltage battery, and a DCDC. The high-voltage battery pack comprises a high-voltage battery and a high-voltage battery management system. The high-voltage battery management system comprises: an isolation module, a MOSFET module, and a control module. The DCDC is connected to the high-voltage battery management system, the low-voltage battery is connected to an output end of the DCDC, and the DCDC is used for converting a high voltage of the high-voltage battery into a low-voltage power and supplying power to the low-voltage battery; an output end of the low-voltage battery is connected to the high-voltage battery management system and used for supplying power to the high-voltage battery management system; the isolation module is connected to a battery cell of the high-voltage battery, and when the low-voltage battery is under-voltage, the MOSFET module is used for switching to the battery cell of the high-voltage battery to supply power to the high-voltage battery management system; and the high-voltage battery management system, when being powered by the battery cell of the high-voltage battery, is used for waking up the DCDC to supply power to the low-voltage battery. Once the technical solution is used, the low-voltage battery can be charged in time when the low-voltage battery of the vehicle is under-voltage, ensuring normal starting of the vehicle.

Description

A battery management system and method for a vehicle, a vehicle Technical Field

[0001] The present invention relates to the field of vehicles, and in particular to a battery management system and method for a vehicle, and a vehicle. Background Art

[0002] Existing electric vehicles use low-voltage batteries to power the vehicle's ECU. When the low-voltage battery is powered, the high-voltage battery management system and other ECUs cannot be awakened, resulting in the high-voltage system being unable to connect normally and the vehicle being unable to start normally. Summary of the Invention

[0003] In order to overcome the above technical deficiencies, an object of the present invention is to provide a battery management system that can enable a vehicle to start normally even when powered by a low-voltage battery.

[0004] Specifically, the present invention provides a vehicle battery management system, including a high-voltage battery pack, a low-voltage battery and a DCDC.

[0005] The high-voltage battery pack includes a high-voltage battery and a high-voltage battery management system, and the high-voltage battery management system includes: an isolation module, a MOSFET module and a control module;

[0006] The DCDC is connected to a high-voltage battery management system, and the low-voltage battery is connected to an output end of the DCDC. The DCDC is used to convert the high voltage of the high-voltage battery into low voltage electricity to supply power to the low-voltage battery;

[0007] The output end of the low-voltage battery is connected to the high-voltage battery management system for supplying power to the high-voltage battery management system;

[0008] The isolation module is connected to the cell of the high-voltage battery. When the low-voltage battery supplies power, the MOSFET module is used to switch the cell of the high-voltage battery to supply power to the high-voltage battery management system.

[0009] The high-voltage battery management system is used to wake up the DCDC and supply power to the low-voltage battery when the high-voltage battery cells are used for power supply.

[0010] Preferably, the high-voltage battery management system further includes a power management chip and a latch;

[0011] The MOSFET module includes a first MOS transistor, a second MOS transistor, a third MOS transistor, and a fourth MOS transistor, wherein the drain of the first MOS transistor is connected to the isolation module, the gate of the first MOS transistor is connected to the low-voltage battery, and the source of the first MOS transistor is connected to the drain of the second MOS transistor;

[0012] The source of the second MOS transistor is connected to the power management chip, and the gate of the second MOS transistor is connected between the gate of the first MOS transistor and the low-voltage battery;

[0013] The source of the third MOS transistor is connected between the source of the second MOS transistor and the power management chip, the gate of the third MOS transistor is connected between the source of the first MOS transistor and the drain of the second MOS transistor, and the drain of the third MOS transistor is connected between the gate of the second MOS transistor and the low-voltage battery;

[0014] The drain of the fourth MOS transistor is connected between the drain of the first MOS transistor and the isolation module, the source of the fourth MOS transistor is connected between the gate of the second MOS transistor and the low-voltage battery via the drain of the third MOS transistor, and the source of the fourth MOS transistor is communicatively connected to the latch;

[0015] The first end of the latch is communicatively connected to the power management chip, and the second end of the latch is communicatively connected to the control module.

[0016] Preferably, the isolation module is connected between the input and output ends of the cell of the high-voltage battery. When the low-voltage battery is powered, the isolation module is used to convert the high-voltage electricity output by the cell of the high-voltage battery into low-voltage electricity, and supply power to the high-voltage battery management system via the MOSFET module.

[0017] The MOSFET module is used to send a first wake-up signal to the control module to wake up the control module, and the control module is used to wake up the DCDC according to the first wake-up signal.

[0018] Preferably, the high-voltage battery pack includes a first relay, a second relay and a third relay, the first relay is provided at the output end of the high-voltage battery, and the second relay is connected in parallel with the first relay;

[0019] The third relay is provided at the input end of the high-voltage battery;

[0020] The control module is communicatively connected to the first relay, the second relay, and the third relay, and the control module is configured to control the first relay, the second relay, and the third relay to be closed according to the first wake-up signal;

[0021] The control module is used to send a second wake-up signal to the DCDC according to the first wake-up signal, and the DCDC is used to convert the high voltage electricity of the high voltage battery into low voltage electricity according to the second wake-up signal to supply power to the low voltage battery.

[0022] Preferably, the high-voltage battery pack includes a current sensor, which is provided between the input end of the cell of the high-voltage battery and the third relay, and the isolation module is connected between the third relay and the current sensor;

[0023] The current sensor is communicatively connected to the control module, and is used to detect the real-time current of the high-voltage battery management system and send the real-time current to the control module.

[0024] Preferably, the DCDC is used to supply power to the low-voltage battery. When the voltage of the low-voltage battery reaches the power supply voltage of the low-voltage battery, the MOSFET module is used to switch the low-voltage battery to supply power to the high-voltage battery management system.

[0025] Preferably, the DCDC is used to supply power to the low-voltage battery until a charging time threshold is reached;

[0026] The control module is used to control the first relay, the second relay and the third relay to be disconnected, and to control the latch to be reset, so that the high-voltage battery management system is in sleep mode.

[0027] Another aspect of the present invention further discloses a battery management method for a vehicle, which applies any of the above-described battery management systems for a vehicle.

[0028] Another aspect of the present invention further discloses a vehicle, comprising any one of the above-described battery management systems for a vehicle.

[0029] After adopting the above technical solution, compared with the existing technology, it has the following beneficial effects: by adding an isolation module and a MOSFET module to the high-voltage battery management system, the isolation module can convert the high voltage electricity in the high-voltage battery into low-voltage power supply, and the MOSFET module can switch to the internal battery cell of the high-voltage battery for power supply when the low-voltage battery power supply voltage is insufficient, and at the same time wake up the high-voltage battery management system, thereby ensuring the normal start-up of the vehicle.

[0030] Summary of the Figures

[0031] In order to make the above-mentioned objects, features and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings, wherein:

[0032] FIG1 is a schematic diagram of a battery management system for a vehicle in the prior art;

[0033] FIG2 is a schematic diagram of a battery management system for a vehicle according to an embodiment of the present invention.

[0034] Preferred embodiments of the present invention

[0035] The advantages of the present invention are further described below with reference to the accompanying drawings and specific embodiments.

[0036] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0037] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0038] It should be understood that although the terms first, second, third, etc. may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining."

[0039] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal communication between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0040] In the following description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention and have no specific meaning. Therefore, "module" and "component" can be used interchangeably.

[0041] Figure 1 is a schematic diagram of a battery management system for a vehicle in the prior art. The right side of the figure shows the circuit connection relationship, and the left side shows the power conversion relationship. Existing electric vehicles use a low-voltage battery to power the ECU on the vehicle. In the figure, when the voltage of the low-voltage battery (usually 12V) is within the normal power supply range, the HVBMS (High Voltage Battery Management System) is powered by the low-voltage battery. When a wake-up signal is received, the HV BMS supplies power to the DCDC and wakes up the DCDC. The HV BMS starts the normal high-voltage process, closes the first relay and the third relay, and connects the high-voltage line. The DCDC then converts the high-voltage electricity into low-voltage electricity to charge the low-voltage battery.

[0042] However, when the low-voltage battery is feeding power, the HV BMS and ECU cannot be woken up normally, and the vehicle cannot start normally. It should be noted that the feeding situation described in the present invention refers to the situation where the voltage provided by the low-voltage battery cannot wake up the BMS and other ECUs.

[0043] Correspondingly, FIG2 is a schematic diagram of a battery management system for a vehicle in an embodiment of the present invention. Similarly, the right side of the figure shows the circuit connection relationship, and the left side shows the power conversion relationship.

[0044] As can be seen from FIG2 , the battery management system in this embodiment includes: a high-voltage battery pack, a low-voltage battery, and a DCDC.

[0045] The high-voltage battery pack includes a high-voltage battery and a high-voltage battery management system (HV BMS). The HV BMS further includes an isolation module, a MOSFET module, and a control module. In this embodiment, the control module is an MCU.

[0046] The DCDC is connected to the high-voltage battery management system, and the low-voltage battery is connected to the output of the DCDC. The DCDC is used to convert the high voltage of the high-voltage battery into low voltage electricity to supply power to the low-voltage battery. The output of the low-voltage battery is connected to the high-voltage battery management system to supply power to the high-voltage battery management system.

[0047] The isolation module is connected to the battery cell of the high-voltage battery. When the low-voltage battery is powered, the MOSFET module can switch the battery cell of the high-voltage battery to power the high-voltage battery management system; the high-voltage battery management system is used to wake up the DCDC and supply power to the low-voltage battery when powered by the battery cell of the high-voltage battery.

[0048] 2 includes a specific circuit diagram of the MOSFET module, including: a first MOS tube, a second MOS tube, a third MOS tube and a fourth MOS tube.

[0049] As can be seen from the figure, the drain of the first MOS transistor is connected to the isolation module, the gate of the first MOS transistor is connected to the low-voltage battery, and the source of the first MOS transistor is connected to the drain of the second MOS transistor.

[0050] The source of the second MOS tube is connected to the power management chip, and the gate of the second MOS tube is connected between the gate of the first MOS tube and the low-voltage battery.

[0051] The source of the third MOS tube is connected between the source of the second MOS tube and the power management chip, the gate of the third MOS tube is connected between the source of the first MOS tube and the drain of the second MOS tube, and the drain of the third MOS tube is connected between the gate of the second MOS tube and the low-voltage battery.

[0052] The drain of the fourth MOS transistor is connected between the drain of the first MOS transistor and the isolation module, the source of the fourth MOS transistor is connected between the gate of the second MOS transistor and the low-voltage battery via the drain of the third MOS transistor, and the source of the fourth MOS transistor is communicatively connected to the latch.

[0053] The first end of the latch is communicatively connected to the power management chip (SBC, System Base Chip), and the second end of the latch is communicatively connected to the control module.

[0054] Based on the above, it can be seen that in this embodiment, the functional properties of the P-type MOSFET are used to control the on / off of the circuit through the voltage difference between the source and the gate. Specifically, when the voltage of the low-voltage battery is normal, the first MOS tube is cut off, the second MOS tube is cut off, the third MOS tube is turned on, and the BMS is powered by the low-voltage battery. The fourth MOS tube is cut off and cannot send a wake-up signal. When the voltage of the low-voltage battery is lower than the threshold and cannot supply power normally, the first MOS tube is turned on, the second MOS tube is turned on, the third MOS tube is cut off, and the BMS is powered by the internal battery cell of the high-voltage battery. The fourth MOS tube is turned on, thereby sending a first wake-up signal.

[0055] The isolation module in this embodiment is connected between the input and output terminals of the high-voltage battery cell. When the low-voltage battery is feeding power, the isolation module is used to convert the high-voltage power output by the high-voltage battery cell into low-voltage power, which is then fed to the high-voltage battery management system via the MOSFET module. This solves the technical problem that the low-voltage battery cannot feed power to the HV BMS.

[0056] At the same time, the MOSFET module sends a first wake-up signal to the control module, waking up the MCU. The MCU then sends a second wake-up signal to the DCDC based on the first wake-up signal. The DCDC then converts the high voltage of the high-voltage battery into low voltage based on the second wake-up signal, supplying power to the low-voltage battery. This allows charging of a low-voltage battery in a feeding state. Specifically, the latch is linked to the MCU. After the MCU is awakened by the SBC, it can detect the input voltage and determine whether the wake-up signal it receives is the first wake-up signal, i.e., the signal source is the wake-up signal of the MOSFET module.

[0057] Furthermore, in this embodiment, the high-voltage battery pack includes a first relay, a second relay, and a third relay. The first relay is located at the output terminal of the high-voltage battery, the second relay is connected in parallel with the first relay, and the third relay is located at the input terminal of the high-voltage battery. The MCU is communicatively connected to the first, second, and third relays and can control the closure of the first, second, and third relays based on the first wake-up signal.

[0058] Furthermore, the high-voltage battery pack further includes a current sensor, which is provided between the input end of the cell of the high-voltage battery and the third relay, and the isolation module is connected between the third relay and the current sensor;

[0059] The current sensor is communicatively connected to the control module, and is used to detect the real-time current of the high-voltage battery management system and send the real-time current to the control module.

[0060] In addition, the DCDC in this embodiment continuously provides a stable current to the low-voltage battery for charging. When the voltage of the low-voltage battery reaches the power supply voltage of the low-voltage battery, the MOSFET module is used to switch the power supply from the low-voltage battery to the HV BMS. The DCDC continues to supply power to the low-voltage battery until a charging time threshold is reached. At this time, the control module is used to control the first relay, the second relay and the third relay to be disconnected, and to control the latch to be reset, and the high-voltage battery management system enters a dormant state. At this time, since the low-voltage battery has reached the power supply voltage, the vehicle can be started normally. When the vehicle is powered on, the control module first controls the second relay to close, then closes the first relay and the third relay, and then disconnects the second relay.

[0061] Based on the above, the vehicle battery management system (HVBMS) of the present invention incorporates a software strategy. When the wakeup source is detected as a MOSFET module input, the relay is closed, enabling the DC-DC converter (DC-DC converter), allowing the high-voltage battery to charge the low-voltage battery. At the start of charging, the low-voltage terminal voltage is equal to the DC-DC converter output voltage, exceeding the supply voltage range. The HVBMS switches to the low-voltage battery terminal for power supply, and the latch maintains the wakeup state. When the set charging time threshold is reached, the relay is disconnected, cutting off the DC-DC converter power supply. The MCU resets the latch, shutting off the wakeup source and placing the HVBMS in sleep mode. This ensures that the low-voltage battery is promptly charged when the vehicle's low-voltage battery is feeding power, ensuring the vehicle's normal startup.

[0062] In another embodiment of the present invention, a battery management method for a vehicle using the above-mentioned management system is provided, which is not described in detail herein. In another embodiment of the present invention, a vehicle is provided, comprising the above-mentioned battery management system for a vehicle, which is not described in detail herein.

[0063] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A battery management system for a vehicle, comprising a high-voltage battery pack, a low-voltage battery, and a DCDC, characterized in that the high-voltage battery pack includes a high-voltage battery and a high-voltage battery management system, and the high-voltage battery management system includes: an isolation module, a MOSFET module, and a control module; the DCDC is connected to the high-voltage battery management system, the low-voltage battery is connected to the output terminal of the DCDC, and the DCDC is used to convert the high voltage of the high-voltage battery into low voltage electricity to supply power to the low-voltage battery; the output terminal of the low-voltage battery is connected to the high-voltage battery management system and is used to supply power to the high-voltage battery management system; the isolation module is connected to the battery cells of the high-voltage battery. When the low-voltage battery is powered, the MOSFET module is used to switch the power supply from the battery cells of the high-voltage battery to the high-voltage battery management system; the high-voltage battery management system is used to wake up the DCDC and supply power to the low-voltage battery when powered by the battery cells of the high-voltage battery.

2. The battery management system for a vehicle according to claim 1, characterized in that the high-voltage battery management system further includes a power management chip and a latch; the MOSFET module includes a first MOS transistor, a second MOS transistor, a third MOS transistor, and a fourth MOS transistor. The drain of the first MOS transistor is connected to the isolation module, the gate of the first MOS transistor is connected to the low-voltage battery, and the source of the first MOS transistor is connected to the drain of the second MOS transistor; the source of the second MOS transistor is connected to the power management chip, the gate of the second MOS transistor is connected between the gate of the first MOS transistor and the low-voltage battery, and the power management chip is used to supply power to the control module; the source of the third MOS transistor is connected between the source of the second MOS transistor and the power management chip, the gate of the third MOS transistor is connected between the source of the first MOS transistor and the drain of the second MOS transistor, and the drain of the third MOS transistor is connected between the gate of the second MOS transistor and the low-voltage battery; the drain of the fourth MOS transistor is connected between the drain of the first MOS transistor and the isolation module, the source of the fourth MOS transistor is connected to the gate of the second MOS transistor and the low-voltage battery via the drain of the third MOS transistor, and the source of the fourth MOS transistor is communicatively connected to the latch; the first end of the latch is communicatively connected to the power management chip, and the second end is communicatively connected to the control module.

3. The battery management system for a vehicle according to claim 2, characterized in that the isolation module is connected between the input terminal and the output terminal of the battery cells of the high-voltage battery. When the low-voltage battery is powered, the isolation module is used to convert the high voltage output by the battery cells of the high-voltage battery into low voltage electricity and supply power to the high-voltage battery management system via the MOSFET module; The MOSFET module is used to send a first wake-up signal to the control module to wake up the control module, and the control module is used to wake up the DCDC according to the first wake-up signal.

4. The battery management system for a vehicle according to claim 3, wherein the high-voltage battery pack includes a first relay, a second relay, and a third relay. The first relay is disposed at the output end of the high-voltage battery, and the second relay is connected in parallel with the first relay; the third relay is disposed at the input end of the high-voltage battery; the control module is communicatively connected to the first relay, the second relay, and the third relay, and the control module is used to control the first relay, the second relay, and the third relay to close according to the first wake-up signal; the control module is used to send a second wake-up signal to the DCDC according to the first wake-up signal, and the DCDC is used to convert the high-voltage power of the high-voltage battery into low-voltage power according to the second wake-up signal and supply power to the low-voltage battery.

5. The battery management system for a vehicle according to claim 4, wherein the high-voltage battery pack includes a current sensor disposed between the input end of the battery cell of the high-voltage battery and the third relay, and the isolation module is connected between the third relay and the current sensor; the current sensor is communicatively connected to the control module, and the current sensor is used to detect the real-time current of the high-voltage battery management system and send the real-time current to the control module.

6. The battery management system for a vehicle according to claim 5, wherein the DCDC is used to supply power to the low-voltage battery. When the voltage of the low-voltage battery reaches the supply voltage of the low-voltage battery, the MOSFET module is used to switch to supply power from the low-voltage battery to the high-voltage battery management system.

7. The battery management system for a vehicle according to claim 6, wherein the DCDC is used to supply power to the low-voltage battery until a charging time threshold is reached; the control module is used to control the first relay, the second relay, and the third relay to disconnect, and control the latch to reset, and the high-voltage battery management system goes to sleep.

8. A battery management method for a vehicle, characterized in that, Apply the battery management system for a vehicle according to any one of claims 1-7.

9. A vehicle, characterized in that, Include the battery management system for a vehicle according to any one of claims 1-7.

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