Vehicle power supply system, control method of vehicle power supply system and vehicle

Abstract

The invention relates to a vehicle power supply system, a control method of the vehicle power supply system and a vehicle. In the vehicle power supply system, a first DCDC conversion module is electrically connected with a power battery system through a first switch unit; the second DCDC conversion module is electrically connected with the power battery system; the first switch unit is a normally closed switch; the first DCDC conversion module is also electrically connected with the second switch unit; the rated power of the first DCDC conversion module is smaller than that of the second DCDC conversion module; the first DCDC conversion module and the second DCDC conversion module are both used for converting high voltage provided by the power battery system into low voltage. The first DCDC conversion module provided by the embodiment of the invention is relatively small in structure and relatively low in cost, and the first DCDC conversion module is arranged in the whole vehicle, so that the weight and the cost of the vehicle can be reduced, and miniaturization of the vehicle is facilitated.

Description

Technical Field

[0001] The present disclosure relates to the field of vehicle technology, and in particular to a vehicle power supply system, a control method of the vehicle power supply system, and a vehicle. Background Art

[0002] At present, the new energy vehicle industry still needs a low-voltage power supply to maintain the operation of related devices such as automotive electronics and electrical appliances. The current solution is to use a single DCDC converter and an independent low-voltage power module to supply 12V or 24V and other low-voltage power supplies required by the entire vehicle. Independent low-voltage power modules include 12V / 24V lead-acid batteries, 12V / 24V lithium batteries, etc., but traditional lead-acid batteries are heavy, have a short lifespan, and poor reliability, which often causes cars to break down. Lithium-ion batteries are used as auxiliary power sources for automobiles, but lithium-ion batteries are expensive and easily affected by the environment, resulting in a rapid decline in product reliability and low product maturity.

[0003] Therefore, how to meet the low-voltage requirements of the vehicle and improve the safety and reliability of the overall battery system, while reducing the cost of the low-voltage auxiliary power supply of the vehicle and improving the overall cost performance of the battery system is an issue that needs to be addressed urgently. Summary of the invention

[0004] In order to solve the above technical problems, the present disclosure provides a vehicle power supply system, a control method of the vehicle power supply system, and a vehicle.

[0005] In a first aspect, the present disclosure provides a vehicle power supply system, including: a first DCDC conversion module, a second DCDC conversion module, a first switch unit, and a power battery system; The first DCDC conversion module is electrically connected to the power battery system through a first switch unit; the second DCDC conversion module is electrically connected to the power battery system; the first switch unit is a normally closed switch; the rated power of the first DCDC conversion module is less than the rated power of the second DCDC conversion module; The first DCDC conversion module and the second DCDC conversion module are both used to convert the high voltage provided by the power battery system into a low voltage.

[0006] In some embodiments, the first DCDC conversion module includes a positive input terminal and a negative input terminal; The power battery system includes multiple battery cells, each of which is connected in series; the first end of the power battery system is electrically connected to the first battery cell, and the second end of the power battery system is electrically connected to the last battery cell; the positive input end is electrically connected to the first end of the power battery system through the first switch unit, and the negative input end is electrically connected to the second end of the power battery system through the first switch unit.

[0007] In some embodiments, the first DCDC conversion module includes a positive input terminal and a negative input terminal; the power battery system includes a plurality of battery cells, each of which is connected in series; the power battery system includes a first terminal, a second terminal and at least one intermediate terminal; It also includes a power management module; the power management module is connected to the first DCDC conversion module; the intermediate connection end is electrically connected to the battery cell located between the first battery cell and the last battery cell, dividing the plurality of battery cells into at least two sub-battery cell intervals; The power management module is used to obtain the working parameters of each of the battery cells to determine the sub-battery cell interval in a thermal runaway state, and send it to the first DCDC conversion module; the first DCDC conversion module controls the first switch unit to be connected to the corresponding port of the sub-battery cell interval that is not in a thermal runaway state in the power battery system.

[0008] In some embodiments, the intermediate connection terminal of the power battery system includes a third terminal; The third end divides the plurality of battery cells into a first sub-battery cell interval and a second sub-battery cell interval; The first DCDC conversion module is used to control the electrical connection between the first DCDC conversion module and the port corresponding to the second sub-battery cell interval based on the first sub-battery cell interval being in a thermal runaway state, and to control the electrical connection between the first DCDC conversion module and the port corresponding to the first sub-battery cell interval based on the second sub-battery cell interval being in a thermal runaway state.

[0009] In some embodiments, the first switch unit includes a first gate switch and a second gate switch; The fixed end of the first gating switch is electrically connected to the positive input end of the first DCDC conversion module; the switching end of the first gating switch is electrically connected to the first end or the third end of the power battery system; the fixed end of the second gating switch is electrically connected to the negative input end of the first DCDC conversion module; the switching end of the second gating switch is electrically connected to the second end or the third end of the power battery system; The switching end of the first gating switch and the switching end of the second gating switch cannot be switched to the third end at the same time.

[0010] In some embodiments, a second switch unit is further included; The second DCDC conversion module is electrically connected to the power battery system through the second switch unit; the second switch unit is also electrically connected to the first DCDC conversion module; The first DCDC conversion module is also used to determine that the vehicle is in a power-on completion state based on the vehicle operating state, and control the second switch unit to be turned on, so that the second DCDC conversion module converts the high voltage provided by the power battery system into a low voltage.

[0011] In some embodiments, the first DCDC conversion module is located inside the power battery system.

[0012] In a second aspect, the present disclosure further provides a control method for a vehicle power supply system, which is applied to any of the vehicle power supply systems provided in the first aspect; the control method comprises: Based on the first switch unit being a normally closed switch, controlling the first DCDC conversion module and the second conversion module to convert the high voltage provided by the power battery system into a low voltage; Wherein, the rated power of the first DCDC conversion module is less than the rated power of the second DCDC conversion module.

[0013] In some embodiments, it also includes: Determining a sub-cell interval in the power battery system that is in a thermal runaway state; Based on the sub-cell interval in the thermal runaway state, the first switch unit is controlled to be connected to a corresponding port of the sub-cell interval in the power battery system that is not in the thermal runaway state.

[0014] In some embodiments, the controlling the second conversion module to convert the high voltage provided by the power battery system into a low voltage further includes: Get the vehicle running status; Based on the vehicle running state, it is determined that the vehicle is in a power-on completion state, and the second switch unit is controlled to be turned on to control the second DCDC conversion module to convert the high voltage provided by the power battery system into a low voltage.

[0015] In some embodiments, it also includes: Determining that the vehicle is in a power-off state or in a power-on process based on the vehicle operating state, controlling the second switch unit to be turned off so that the second DCDC conversion module stops converting the high voltage provided by the power battery system into a low voltage.

[0016] In a third aspect, the present disclosure further provides a vehicle, comprising any vehicle power supply system as provided in the first aspect.

[0017] Compared with the prior art, the technical solution provided by the present invention has the following advantages: The vehicle power supply system provided by the present disclosure electrically connects the first DCDC conversion module to the power battery system, and the first DCDC conversion module and the power battery system are in a normally closed connection mode, thereby replacing the low-voltage power supply in the prior art. The rated power of the first DCDC conversion module is lower than the rated power of the second DCDC conversion module. Both the first DCDC conversion module and the second DCDC conversion module can convert the high voltage provided by the power battery system into low voltage to meet the power distribution requirements of the low-voltage load of the vehicle. Since the first DCDC conversion module has a small structure and low cost, setting it in the whole vehicle can reduce the weight and cost of the vehicle, which is conducive to the miniaturization of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0020] Figure 1 A schematic diagram of the structure of a vehicle power supply system provided by an embodiment of the present disclosure; Figure 2 A schematic diagram of the structure of another vehicle power supply system provided by an embodiment of the present disclosure; Figure 3 A schematic diagram of another vehicle power supply system provided in an embodiment of the present disclosure Figure 4 A schematic diagram of the structure of another vehicle power supply system provided by an embodiment of the present disclosure; Figure 5 A schematic diagram of a circuit when a first sub-cell interval fails provided by an embodiment of the present disclosure; Figure 6 A schematic diagram of a circuit when a second sub-cell interval fails provided by an embodiment of the present disclosure; Figure 7 A schematic diagram of the structure of another vehicle power supply system provided by an embodiment of the present disclosure; Figure 8 A flow chart of a control method for a vehicle power supply system provided by an embodiment of the present disclosure; Fig. 9 A schematic diagram of the structure of a vehicle provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0021] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0022] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0023] In order to solve the above defects, the present disclosure provides a vehicle power supply system. Figure 1 A schematic diagram of a vehicle power supply system according to an embodiment of the present disclosure is provided. Figure 1 The vehicle power supply system includes: a first DCDC conversion module 10, a second DCDC conversion module 20, a first switch unit 11 and a power battery system 30.

[0024] The first DCDC conversion module 10 is electrically connected to the power battery system 30 through the first switch unit 11; the second DCDC conversion module 20 is electrically connected to the power battery system 30; the first switch unit 11 is a normally closed switch; the rated power of the first DCDC conversion module 10 is less than the rated power of the second DCDC conversion module 20. The first DCDC conversion module 10 and the second DCDC conversion module 20 are both used to convert the high voltage provided by the power battery system 30 into a low voltage.

[0025] Exemplarily, the disclosed embodiment includes a first DCDC conversion module 10 and a second DCDC conversion module 20, both of which are electrically connected to a power battery system 30, and are used to convert the high voltage provided by the power battery system 30 into a low voltage, thereby supplying power to the low-voltage load in the vehicle. The power battery system 30 may be a power battery of the vehicle, which may obtain power from the power grid through a fast charging pile, or from an onboard charger.

[0026] Among them, the rated power of the first DCDC conversion module 10 is lower than the rated power of the second DCDC conversion module 20. The first DCDC conversion module is electrically connected to the power battery system 30 through the first switch unit 11, and the first switch unit 11 is a normally closed switch. Therefore, the first DCDC conversion module 10 and the power battery system 30 are in a continuous connection state, and no additional control signal is required to control the conduction and shutdown of the first DCDC conversion module 10 and the power battery system 30. The rated power of the first DCDC conversion module 10 is relatively low, for example, the rated power range is set to 0~1000W. When the power battery system 30 stores enough electricity, the first DCDC conversion module 10 can continuously convert the high voltage of the power battery system 30 into a low voltage, for example, into a low voltage of 12V. Therefore, the first DCDC conversion module 10 combined with the power battery system 30 in the vehicle can be used as a low-voltage auxiliary power supply for the whole vehicle, without the need to set a low-voltage battery module to power the low-voltage load of the vehicle, reducing the cost and weight of the whole vehicle, which is conducive to lightweighting of the vehicle and can bring lower power consumption or fuel consumption. Furthermore, the second DCDC conversion module 20 is electrically connected to the power battery system 30 , so that both the first DCDC conversion module 10 and the second DCDC conversion module can convert the high voltage provided by the power battery system 30 into a low voltage to supply power to the low-voltage load of the vehicle.

[0027] The vehicle power supply system provided by the embodiment of the present disclosure electrically connects the first DCDC conversion module to the power battery system. The first DCDC conversion module and the power battery system are in a normally closed connection mode, thereby replacing the low-voltage power supply in the prior art. The rated power of the first DCDC conversion module is lower than the rated power of the second DCDC conversion module. Both the first DCDC conversion module and the second DCDC conversion module can convert the high voltage provided by the power battery system into low voltage to meet the power distribution requirements of the low-voltage load of the vehicle. Since the first DCDC conversion module has a small structure and low cost, it is set in the whole vehicle, which can reduce the weight and cost of the vehicle.

[0028] In some embodiments, Figure 2 A schematic diagram of a vehicle power supply system according to an embodiment of the present disclosure is provided. Figure 2 The first DCDC conversion module 10 includes a positive input terminal V+ and a negative input terminal V-; the power battery system 30 includes a plurality of battery cells, each of which is connected in series; the first end 31 of the power battery system 30 is electrically connected to the first battery cell, and the second end 32 of the power battery system 30 is electrically connected to the last battery cell; the positive input terminal V+ is electrically connected to the first end 31 of the power battery system 30 through the first switch unit 11, and the negative input terminal V- is electrically connected to the second end 32 of the power battery system 30 through the first switch unit 11.

[0029] Exemplarily, the first DCDC conversion module includes two input terminals, namely a positive input terminal V+ and a negative input terminal V-, for being electrically connected to the power battery system 30. The power battery system 30 includes a plurality of battery cells, each of which is connected in series. The number of battery cells is set according to actual needs, and the embodiment of the present disclosure does not set this. Figure 2 The power battery system 30 includes a first end 31 and a second end 32. The first end 31 of the power battery system 30 is connected to the first battery cell ( Figure 2 The second end 32 of the power battery system 30 is electrically connected to the last battery cell ( Figure 2 The first terminal 31 represents the positive terminal of the power battery system 30, and the second terminal 32 represents the negative terminal of the power battery system 30. The positive input terminal V+ is electrically connected to the first terminal 31 of the power battery system 30 through the first switch unit 11, and the negative input terminal V- is electrically connected to the second terminal of the power battery system 30 through the first switch unit 11, so that the first DCDC conversion module 10 is electrically connected to the power battery system 30, and the high voltage provided by the power battery system 30 is converted into a low voltage, thereby supplying power to the low-voltage load in the vehicle. Since the first switch unit 11 is a normally closed switch, the power battery system 30 and the first DCDC conversion module 10 are always in a connected state. However, the first switch unit 11 is set to control the first switch unit 11 to disconnect when some structures of the vehicle fail and the power supply through the first DCDC conversion module 10 needs to be cut off, so as to cut off the connection between the power battery system 30 and the first DCDC conversion module 10, thereby ensuring the safety of the vehicle.

[0030] In some embodiments, Figure 3 A schematic diagram of the structure of another vehicle power supply system provided in an embodiment of the present disclosure is shown in FIG. Figure 4 A schematic diagram of a vehicle power supply system according to an embodiment of the present disclosure is provided. Figure 3 and Figure 4 The first DCDC conversion module 10 includes a positive input terminal V+ and a negative input terminal V-; the power battery system 30 includes a plurality of battery cells, each of which is connected in series; the power battery system 30 includes a first terminal 31, a second terminal 32 and at least one intermediate terminal.

[0031] The vehicle power supply system also includes a power management module 40; the power management module 40 is connected to the first DCDC conversion module 10; the intermediate connection end is electrically connected to the battery cell located between the first battery cell and the last battery cell, dividing the multiple battery cells into at least two sub-battery cell intervals.

[0032] The power management module 40 is used to obtain the working parameters of each battery cell to determine the sub-battery cell interval in a thermal runaway state, and send it to the first DCDC conversion module 10; the first DCDC conversion module 10 controls the first switch unit 11 to connect to the corresponding port of the sub-battery cell interval that is not in a thermal runaway state in the power battery system 30.

[0033] For example, reference Figure 3 , provides an overall layout of the vehicle power supply system, the vehicle power supply system also includes a power management module 40, the power management module 40 is connected to the first DCDC conversion module 10, the power management module 40 can obtain various working information of the vehicle and the working parameters of each battery cell in the power battery system 30. Figure 4 , the first DCDC conversion module 10 in the embodiment of the present disclosure includes a positive input terminal V+ and a negative input terminal V-, and the power battery system 30 includes a plurality of battery cells, each of which is connected in series. The power battery system 30 includes a first terminal 31 and a second terminal 32, and also includes at least one intermediate connection terminal, and the intermediate connection terminal is located between the first battery cell and the last battery cell. The battery cells can be divided into at least two sub-battery cell intervals. For example, if m intermediate connection terminals are included, and n intermediate connection terminals are respectively electrically connected to the m battery cells directly connected to the first battery cell and the last battery cell, the battery cells can be divided into multiple sub-battery cell intervals. The above structure can avoid the problem of thermal runaway due to a certain battery cell failure, which affects the operation of the entire power battery system 30 and various devices in the vehicle.

[0034] Specifically, the power management module 40 is connected to the power battery system 30, and can obtain the working parameters of each battery cell in the power battery system 30, such as collecting the voltage and temperature change rate of the single battery cell, and judging whether the battery cell is faulty based on the change of the voltage and temperature change rate. When the battery cell fails, the voltage decreases and the temperature change rate increases. At this time, the power management module 40 determines that the single battery cell fails and the sub-battery cell interval in which the battery cell is located is in a thermal runaway state. The power management module 40 can send the information to the control unit of the first DCDC conversion module 10 through CAN (Controller Area Network, Controller Local Area Network Bus) communication or LIN (Local Interconnect Network, Low-speed Serial Communication Bus) communication. The control unit in the first DCDC conversion module 10 will judge the received information based on the acquired signal, and determine the corresponding sub-battery cell interval with the maximum power when the battery cell is excluded from the power battery system 30. And control the first switch unit 11 to connect to the corresponding port of the sub-battery cell interval that is not in a thermal runaway state and has the maximum power in the power battery system 30. Removing the faulty battery cell from the power battery system 30 will neither affect the power battery system 30 from continuing to supply power to the load nor damage other devices in the circuit.

[0035] It should be noted that the connection method between the power management module and the power battery system in the embodiment of the present disclosure is not limited. It is a common technical means used by technical personnel in this field. Therefore, the embodiment of the present disclosure does not limit this. It is only used to indicate that the power management module can monitor the power battery system and obtain a series of data information.

[0036] Optional, Figure 3 The medium and fast charging pile or the on-board charger provides high voltage electricity to the power battery system 30, the inverter, and the air conditioning, brake, and turn signal modules through the high voltage distribution box. Among them, the inverter is electrically connected to the motor. The power battery system 30 is powered by the first DCDC conversion module 10 and the second DCDC conversion module 20 respectively. The first DCDC conversion module 10 and the second DCDC conversion module 20 convert the high voltage provided by the power battery system 30 into low voltage, and power the power management module 40, the motor controller, the normal controller and other low-voltage loads.

[0037] In some embodiments, continue to refer to Figure 4 The middle connection end of the power battery system 30 includes a third end 33; the third end 33 divides the multiple cells into a first sub-cell interval A and a second sub-cell interval B. The first DCDC conversion module 10 is used to control the first DCDC conversion module 10 to be electrically connected to the port corresponding to the second sub-cell interval B based on the first sub-cell interval A being in a thermal runaway state, and to control the first DCDC conversion module 10 to be electrically connected to the port corresponding to the first sub-cell interval A based on the second sub-cell interval B being in a thermal runaway state.

[0038] For example, Figure 4The power battery system 30 includes n cells, the first end 31 of the power battery system 30 is electrically connected to the first cell, and the first end 31 is the positive end; the second end 32 of the power battery system 30 is electrically connected to the nth cell, and the second end 32 is the negative end; the relay connection end of the power battery system 30 includes a third end 33, and the third end 33 is located between the first cell and the last cell, and the cell is electrically connected. For example, the i-th cell is located between the first cell and the n-th cell, and the third end 33 is connected to the i-th cell. Thus, the third end 33 divides the multiple cells into a first sub-cell interval A and a second sub-cell interval B. When all the cells in the power battery system 30 are working normally, the positive input terminal V+ of the first DCDC conversion module 10 is electrically connected to the first end 31 of the power battery system 30, and the negative input terminal V- of the first DCDC conversion module is electrically connected to the second end 32 of the power battery system 30. At this time, the power of the power battery system 30 is the maximum. If the power management module 40 determines that there is a faulty cell in the power battery system 30 based on the obtained working parameters of each cell in the power battery system 30, then according to the sub-cell interval in which the cell is located, the connection between each port of the first DCDC conversion module 10 and the power battery system 30 is controlled to eliminate the fault from the power supply cell part.

[0039] Figure 5 A schematic diagram of a circuit when a first sub-cell interval fails is provided in an embodiment of the present disclosure, with reference to Figure 5 For example, if the faulty cell is in the first sub-cell interval A, it is considered that the first sub-cell interval A is in a thermal runaway state, and the first DCDC conversion module 10 is controlled to be electrically connected to the port corresponding to the second sub-cell interval B. That is, the positive input terminal V+ of the first DCDC conversion module 10 is electrically connected to the third terminal 33 of the power battery system 30, and the negative input terminal V- of the first DCDC conversion module is electrically connected to the second terminal 32 of the power battery system 30, and the cells in the second sub-cell interval B are used to supply power to the load. Figure 6 A schematic diagram of a circuit when a second sub-cell interval fails is provided in an embodiment of the present disclosure, referring to Figure 6 For example, if the faulty cell is in the second sub-cell interval B, it is considered that the second cell interval B is in a thermal runaway state, and the first DCDC conversion module 10 is controlled to be electrically connected to the port corresponding to the first sub-cell interval A. That is, the positive input terminal V+ of the first DCDC conversion module 10 is electrically connected to the first terminal 31 of the power battery system 30, and the negative input terminal V- of the first DCDC conversion module is electrically connected to the third terminal 33 of the power battery system 30, and the cells in the first sub-cell interval A are used to supply power to the load.

[0040] Optionally, when no battery cell in the power battery system fails, the positive input terminal of the first DCDC conversion module is electrically connected to the first end of the power battery system, and the negative input terminal of the first DCDC conversion module is electrically connected to the second end of the power battery system, and the power battery system as a whole supplies power to the load.

[0041] Based on the above structure, when thermal runaway occurs in the power battery system, it will take a long time for the thermal runaway to spread to the area without thermal runaway. Therefore, the connection port between the power battery system and the first DCDC conversion module can be quickly switched, and the port of the power battery system can be switched to the non-thermal runaway area to remove the faulty battery cell and continue to input low-voltage auxiliary power to the whole vehicle through the first DCDC conversion module to ensure functional safety redundancy.

[0042] In some embodiments, continue to refer to Figures 4 to 6 The first switch unit 11 includes a first gate switch 111 and a second gate switch 112 .

[0043] The fixed end of the first selection switch 111 is electrically connected to the positive input terminal V+ of the first DCDC conversion module 10; the switching end of the first selection switch 111 is electrically connected to the first end 31 or the third end 33 of the power battery system 30; the fixed end of the second selection switch 112 is electrically connected to the negative input terminal V- of the first DCDC conversion module 10; the switching end of the second selection switch 112 is electrically connected to the second end 32 or the third end 33 of the power battery system 30.

[0044] The switching end of the first selection switch 111 and the switching end of the second selection switch 112 cannot be switched to the third end at the same time.

[0045] For example, reference Figure 4 If there is no faulty battery in the power battery system 30, the switching end of the first selection switch 111 is electrically connected to the first end 31 of the power battery system 30, and the switching end of the second selection switch 112 is electrically connected to the second end 32 of the power battery system 30, and the entire power battery system 30 supplies power to the vehicle. Figure 5 For example, if the faulty cell is in the first sub-cell interval A, and the first sub-cell interval A is in a thermal runaway state, the switching end of the first selection switch 111 is controlled to be electrically connected to the third end 33 of the power battery system 30, and the switching end of the second selection switch 112 is controlled to be electrically connected to the second end 32 of the power battery system 30, and the second sub-cell interval B is used to power the vehicle. Figure 6For example, if the faulty battery cell is in the second sub-battery cell interval B and the second sub-battery cell interval B is in a thermal runaway state, the switching end of the first selection switch 111 is controlled to be electrically connected to the first end 31 of the power battery system 30, and the switching end of the second selection switch 112 is controlled to be electrically connected to the third end 33 of the power battery system 30, and the first sub-battery cell interval A is used to power the vehicle.

[0046] It should be noted that the embodiment of the present disclosure is exemplified by three ports, two sub-cell intervals and two selection switches, and the specific number of ports and the number of sub-cell areas can be designed according to actual needs. In other embodiments, the first switch unit can also be other different design structures, which is not limited by the present disclosure.

[0047] In some embodiments, Figure 7 A schematic diagram of a vehicle power supply system according to an embodiment of the present disclosure is provided. Figure 7 The vehicle power supply system also includes a second switch unit 21.

[0048] The second DCDC conversion module 20 is electrically connected to the power battery system 30 via the second switch unit 21 ; the second switch unit 21 is also electrically connected to the first DCDC conversion module 10 .

[0049] The first DCDC conversion module 10 is further used to determine that the vehicle is in a power-on completion state based on the vehicle operating state, and control the second switch unit 21 to be turned on, so that the second DCDC conversion module 20 converts the high voltage provided by the power battery system 30 into a low voltage.

[0050] Exemplarily, the second DCDC conversion module 20 is electrically connected to the power battery system 30 through the second switch unit 21, and the second switch unit 21 is electrically connected to the first DCDC conversion module 10. The rated power of the second DCDC conversion module 20 is relatively high, for example, the power is 3000W, so considering the vehicle safety and operation requirements, the continuous conduction of the second DCDC conversion module 20 may cause certain safety problems, so the first DCDC conversion module 10 controls the conduction and shutdown of the second switch unit 21 based on the vehicle operation state.

[0051] Specifically, when the vehicle is in the power-on completion state, all components in the vehicle are started and in the running state. To drive the low-voltage load of the whole vehicle, a low-voltage power supply with a relatively high power is required. Therefore, the first DCDC conversion module 10 controls the second switch unit 21 to be turned on, and the connection path between the second DCDC conversion module 20 and the power battery system 30 is turned on. The second DCDC conversion module 20 can convert the high voltage provided by the power battery system 30 into a low voltage to power the whole vehicle. If it is judged based on the vehicle operation state that the vehicle is in the power-on process, the components of the whole vehicle are not fully started, or the vehicle is in the power-off state, then a relatively high-power low-voltage power supply is not required. At this time, the first DCDC conversion module 10 controls the second switch unit 21 to be turned off, and the second DCDC conversion module 20 stops converting the high voltage provided by the power battery system 30 into a low voltage, but the first DCDC conversion module 10 continues to power the low-voltage load in the vehicle. In this way, the power supply demand of the low-voltage load in the vehicle can be met, and the safety and reliability of the vehicle can be improved.

[0052] Optionally, the first DCDC conversion module includes a control unit. The control unit in the first DCDC conversion module 10 can obtain various types of information such as relevant parameters and the operating status of the vehicle from the power management module or other modules of the vehicle, and then control other devices accordingly. The control unit is not described in detail in the embodiment of the present disclosure. It can be considered that it is integrated in the first DCDC conversion module. In other embodiments, it can also be independently set outside the first DCDC conversion module. And the first DCDC conversion module is connected to the second switch, which can be directly electrically connected or indirectly connected through other controllers, power management modules, etc., to achieve the purpose of controlling the second switch unit. The connection method in the embodiment of the present disclosure is only an example, and does not mean that the first DCDC conversion module and the second switch unit can only be directly connected. A variety of omitted circuit modules may be included in the middle.

[0053] In some embodiments, the first DCDC conversion module is located inside the power battery system.

[0054] In the disclosed embodiment, the first DCDC conversion module is combined with the power battery system to replace the low-voltage battery module in the prior art, which not only reduces the cost of the whole vehicle, but also reduces the occupied space, which is conducive to the lightweighting of the vehicle. The first DCDC conversion module is integrated into the power battery system to further reduce the use of space. For example, the first DCDC conversion module can form a PCBA (Printed Circuit Board Assembly) board or a small-sized structural module, and the power battery system includes a shell, and the first DCDC conversion module can be placed inside the shell of the power battery system to reduce space occupation.

[0055] Optionally, the disclosed embodiment may also set a low-power storage battery outside the power battery. The first DCDC conversion module is integrated in the power battery system, and the power management module shares the power battery system. The power management module can perform power calculation and fault diagnosis functions on the external storage battery, and autonomously send a power replenishment request when the battery is low to avoid feeding.

[0056] In the vehicle power supply system provided by the embodiment of the present disclosure, the software structure has also been partially improved accordingly. The software integration module includes ASW (Application Software Layer) and BSW (Basic Software Layer). Among them, ASE includes but is not limited to the use of battery cell voltage, upper and lower high voltage, SOC (State Of Charge), SOP (State Of Power), SOH (State Of Health), battery cell temperature sampling, PACK high voltage sampling, thermal runaway, drive retention and lock power and other functions. ASW adds a drive retention unit and a lock power unit, which corresponds to the partial structure of switching the power battery system port in the hardware structure to continuously supply power to the vehicle load. In addition, a lock power unit is added to control the power battery system to stop supplying power to the outside when the power in the power battery system is low. LIN communication is added to BSW, which can cooperate with the original CAN communication to transmit vehicle signals. A power control unit is also added to BSW to cooperate with the lock power unit. Specifically, the embodiment of the present disclosure does not make specific restrictions on this, and can be set according to actual needs.

[0057] Based on the above structure, an embodiment of the present disclosure further provides a control method for a vehicle power supply system, which is applied to a vehicle power supply system as described in any of the above embodiments. Figure 8 A flow chart of a control method for a vehicle power supply system provided by an embodiment of the present disclosure, referring to Figure 8 , the control method includes S110: S110, based on the first switch unit being a normally closed switch, controlling the first DCDC conversion module and the second conversion module to convert the high voltage provided by the power battery system into a low voltage; The rated power of the first DCDC conversion module is less than the rated power of the second DCDC conversion module.

[0058] The first switch unit in the disclosed embodiment is a normally closed switch, that is, when the first switch unit remains in a normally closed state, the first DCDC conversion module is electrically connected to the power battery system. At this time, the first DCDC conversion module is controlled to convert the high voltage provided by the power battery system into a low voltage, thereby supplying power to the low-voltage load in the vehicle. Similarly, the second DCDC conversion module is also electrically connected to the power battery system, so the second conversion module can be controlled to convert the high voltage provided by the power battery system into a low voltage. The power battery system can be a power battery of the vehicle, which can obtain electricity from the power grid through a fast charging pile, or it can obtain electricity from an on-board charger.

[0059] Among them, the rated power of the first DCDC conversion module is lower than the rated power of the second DCDC conversion module. The first DCDC conversion module can be used as a low-voltage auxiliary power supply for the whole vehicle in combination with the power battery system in the vehicle, without the need to set up a low-voltage battery module to power the low-voltage load of the vehicle, thereby reducing the cost and weight of the whole vehicle, which is conducive to lightweighting of the vehicle and can bring lower power consumption or fuel consumption.

[0060] In some embodiments, it also includes: Determine the sub-cell area in the power battery system that is in thermal runaway state; Based on the sub-cell interval in the thermal runaway state, the first switch unit is controlled to be connected to the corresponding port of the sub-cell interval not in the thermal runaway state in the power battery system.

[0061] Exemplarily, since the power battery system includes multiple battery cells, each battery cell is connected in series to supply power to the vehicle's load. Once a battery cell fails, if it continues to supply power to the vehicle, it will cause serious safety problems, but if the power supply is stopped, it will affect the normal operation of the vehicle. Therefore, the power battery system in the embodiment of the present disclosure is divided into at least two sub-battery cell intervals. If a battery cell in a sub-battery cell interval fails and is in a thermal runaway state, the sub-battery cell interval that is not in a thermal runaway state can supply power to the vehicle, thereby improving the safety of the circuit without affecting the operation of the vehicle.

[0062] Specifically, the vehicle includes a power management module, which can obtain the working parameters of each battery cell in the power battery system, such as collecting the voltage and temperature change rate of the single battery cell, and judging whether the battery cell is faulty based on the change of the voltage and temperature change rate. When the battery cell fails, the voltage decreases and the temperature change rate increases. At this time, the power management module determines that the single battery cell is faulty and the sub-battery cell interval in which the battery cell is located is in a thermal runaway state. The control unit in the first DCDC conversion module can obtain information from the power management module, and judge the received information to determine the corresponding sub-battery cell interval with the maximum power when the battery cell is excluded from the power battery system, and then control the first switch unit to connect to the corresponding port of the sub-battery cell interval that is not in a thermal runaway state and has the maximum power in the power battery system. Removing the faulty battery cell from the power battery system will neither affect the power battery system to continue to supply power to the load nor damage other devices in the circuit.

[0063] In some embodiments, controlling the second conversion module to convert the high voltage provided by the power battery system into a low voltage further includes: Get the vehicle operating status.

[0064] It is determined based on the vehicle running state that the vehicle is in a power-on completion state, and the second switch unit is controlled to be turned on to control the second DCDC conversion module to convert the high voltage provided by the power battery system into a low voltage.

[0065] Exemplarily, when the vehicle is in different operating states, there are differences in the devices in the vehicle that require low-voltage power supply, so the low-voltage load of the vehicle can be powered by conversion modules of different powers. In the embodiment of the present disclosure, the vehicle includes a first DCDC conversion module and a second DCDC conversion module, the rated power of the first DCDC conversion module is less than that of the second DCDC conversion module, and the first DCDC conversion module is connected to the power battery system through a normally closed switch, so the first DCDC is turned on when the vehicle is in different operating states. The power of the second DCDC conversion module is higher. When more loads in the vehicle require low-voltage power supply, the second DCDC conversion module can be combined with the power battery system to power the load. The scenario where more loads require low-voltage power supply is mostly after the vehicle is powered on, and when the vehicle is not powered on, a low-power conversion module is often used for power supply. In this way, the vehicle operating state can be obtained, and then based on the vehicle operating state, it is determined that the vehicle is in a power-on completion state, and the vehicle is driving normally. At this time, it can be understood that various devices in the vehicle require low-voltage power supply, and the first DCDC conversion module cannot meet the demand. At this time, the second switch unit is controlled to be turned on to control the second DCDC conversion module to convert the high voltage provided by the power battery system into low voltage and power the entire vehicle.

[0066] Optionally, when the power converted by the second DCDC conversion module cannot meet the peak power of the entire vehicle, the first DCDC conversion module normally connected to the power battery system can continue to convert the high voltage provided by the power battery system into low voltage and supply power to the entire vehicle.

[0067] In addition, the disclosed embodiment does not limit the method for obtaining the operating status of the vehicle. It can be obtained by the power management module and sent to the control unit of the first DCDC conversion module, and then the control unit of the first DCDC conversion module performs subsequent control. It is also possible that the control unit of the first DCDC conversion module obtains the operating status of the vehicle from other controllers. It can be determined according to the actual circuit structure and the connection relationship between the modules. After the vehicle is powered on, the second switch unit can be controlled to turn on to control the second DCDC conversion module to convert the high voltage provided by the power battery system into a low voltage.

[0068] In some embodiments, it also includes: Based on the vehicle running state, it is determined that the vehicle is in a power-off state or in a power-on process, and the second switch unit is controlled to be turned off so that the second DCDC conversion module stops converting the high voltage provided by the power battery system into a low voltage.

[0069] For example, when the vehicle is in a power-off state or in the power-on process, only some loads in the vehicle need low-voltage power supply. At this time, the first DCDC conversion module converts the high voltage provided by the power battery system into low voltage to power the load, and there is no need for the second DCDC conversion module with higher power to convert the high voltage provided by the power battery system, which can reduce normal power consumption. Therefore, the second switch unit is controlled to be turned off so that the second DCDC conversion module stops converting the high voltage provided by the power battery system into low voltage.

[0070] The embodiments of the present disclosure also provide a vehicle, including the vehicle power supply system described in any of the above embodiments. Since the embodiments of the present disclosure include the vehicle power supply system in any of the above embodiments, they have the same or corresponding beneficial effects as the vehicle power supply systems described in the above embodiments. It should be noted that the electronic device provided by the embodiments of the present disclosure may also include other circuits and devices for supporting its normal operation, and this embodiment does not specifically limit this.

[0071] Fig. 9 A schematic diagram of a vehicle structure provided by an embodiment of the present disclosure, referring to Fig. 9 The vehicle includes a processor 501 and a memory 502. The processor 501 executes the steps of any method in the above embodiments by calling a program or instruction stored in the memory 502.

[0072] Specifically, Fig. 9As shown, the vehicle may include at least one processor 501, at least one memory 502, and at least one communication interface 503. The various components in the vehicle are coupled together via a bus system 504. The communication interface 503 is used to transmit information with external devices. It is understood that the bus system 504 is used to achieve connection and communication between these components. In addition to the data bus, the bus system 504 also includes a power bus, a control bus, and a status signal bus. However, for the sake of clarity, the bus system 504 is not described in detail. Fig. 9 Various buses are labeled as bus system 504 .

[0073] It is understood that the memory 502 in this embodiment may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. In some implementations, the memory 502 stores the following elements: executable units or data structures, or their subsets, or their extended sets of operating systems and applications. In the disclosed embodiment, the processor 501 executes the steps of each embodiment of the method provided in the disclosed embodiment by calling the program or instruction stored in the memory 502.

[0074] The method provided in the embodiment of the present disclosure can be applied to the processor 501, or implemented by the processor 501. The processor 501 can be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in the processor 501 or an instruction in the form of software. The above-mentioned processor 501 can be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0075] The steps of the method provided in the embodiment of the present disclosure can be directly embodied as being executed by a hardware decoding processor, or can be executed by a combination of hardware and software units in the decoding processor. The software unit can be located in a storage medium mature in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 502, and the processor 501 reads the information in the memory 502 and completes the steps of the method in combination with its hardware.

[0076] The embodiments of the present disclosure also provide a computer-readable storage medium, which stores a program or instruction, and the program or instruction enables a computer to execute the steps of any method in the above method embodiments.

[0077] The vehicle may also include one physical component, or multiple physical components, according to the instructions generated by the processor when executing the motor control method provided in the embodiment of the present disclosure. Different physical components can be set inside the vehicle, or outside the vehicle, such as a cloud server, etc. Each physical component cooperates with the processor and the memory to realize the functions of the vehicle in this embodiment.

[0078] The computer-readable storage medium provided by the embodiments of the present disclosure can execute the steps of any one of the methods in the above-mentioned vehicle control method embodiments, and thus can also achieve the same technical effects as the above-mentioned vehicle control method.

[0079] In addition to the above-mentioned method and vehicle, an embodiment of the present application may also be a computer program product, which includes computer program instructions, and when the computer program instructions are executed by a processor, the processor executes the method steps of various embodiments of the present application.

[0080] The computer program product may be written in any combination of one or more programming languages ​​to write program code for performing the operations of the embodiments of the present invention, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a separate software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0081] In addition, the embodiments of the present application may also be a computer-readable storage medium on which computer program instructions are stored. When the computer program instructions are executed by the processor 501, the processor 501 executes the method steps of various embodiments of the present application.

[0082] Computer readable storage media can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can include, for example, but is not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0083] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0084] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A vehicle power supply system, characterized in that: include: A first DCDC conversion module, a second DCDC conversion module, a first switch unit and a power battery system; The first DCDC conversion module is electrically connected to the power battery system through a first switch unit; the second DCDC conversion module is electrically connected to the power battery system; the first switch unit is a normally closed switch; wherein the rated power of the first DCDC conversion module is less than the rated power of the second DCDC conversion module; The first DCDC conversion module and the second DCDC conversion module are both used to convert the high voltage provided by the power battery system into a low voltage.

2. The vehicle power supply system according to claim 1, characterized in that: The first DCDC conversion module includes a positive input terminal and a negative input terminal; The power battery system includes multiple battery cells, each of which is connected in series; the first end of the power battery system is electrically connected to the first battery cell, and the second end of the power battery system is electrically connected to the last battery cell; the positive input end is electrically connected to the first end of the power battery system through the first switch unit, and the negative input end is electrically connected to the second end of the power battery system through the first switch unit.

3. The vehicle power supply system according to claim 1, characterized in that: The first DCDC conversion module includes a positive input terminal and a negative input terminal; the power battery system includes a plurality of battery cells, each of which is connected in series; the power battery system includes a first terminal, a second terminal and at least one intermediate terminal; It also includes a power management module; the power management module is connected to the first DCDC conversion module; the intermediate connection end is electrically connected to the battery cell located between the first battery cell and the last battery cell, dividing the plurality of battery cells into at least two sub-battery cell intervals; The power management module is used to obtain the working parameters of each of the battery cells to determine the sub-battery cell interval in a thermal runaway state, and send it to the first DCDC conversion module; the first DCDC conversion module controls the first switch unit to be connected to the corresponding port of the sub-battery cell interval that is not in a thermal runaway state in the power battery system.

4. The power supply system according to claim 3, characterized in that: The intermediate connection end of the power battery system includes a third end; The third end divides the plurality of battery cells into a first sub-battery cell interval and a second sub-battery cell interval; The first DCDC conversion module is used to control the electrical connection between the first DCDC conversion module and the port corresponding to the second sub-battery cell interval based on the first sub-battery cell interval being in a thermal runaway state, and to control the electrical connection between the first DCDC conversion module and the port corresponding to the first sub-battery cell interval based on the second sub-battery cell interval being in a thermal runaway state.

5. The vehicle power supply system according to claim 4, characterized in that: The first switch unit includes a first gate switch and a second gate switch; The fixed end of the first gating switch is electrically connected to the positive input end of the first DCDC conversion module; the switching end of the first gating switch is electrically connected to the first end or the third end of the power battery system; the fixed end of the second gating switch is electrically connected to the negative input end of the first DCDC conversion module; the switching end of the second gating switch is electrically connected to the second end or the third end of the power battery system; The switching end of the first gating switch and the switching end of the second gating switch cannot be switched to the third end at the same time.

6. The vehicle power supply system according to claim 1, characterized in that: Also includes a second switch unit; The second DCDC conversion module is electrically connected to the power battery system through the second switch unit; the second switch unit is also electrically connected to the first DCDC conversion module; The first DCDC conversion module is further used to determine that the vehicle is in a power-on completion state based on the vehicle operating state, and control the second switch unit to be turned on, so that the second DCDC conversion module converts the high voltage provided by the power battery system into a low voltage.

7. The vehicle power supply system according to claim 1, characterized in that: The first DCDC conversion module is located inside the power battery system.

8. A control method for a vehicle power supply system, characterized in that: Applicable to the vehicle power supply system according to any one of claims 1 to 7; the control method comprises: Based on the first switch unit being a normally closed switch, controlling the first DCDC conversion module and the second conversion module to convert the high voltage provided by the power battery system into a low voltage; Wherein, the rated power of the first DCDC conversion module is less than the rated power of the second DCDC conversion module.

9. The control method according to claim 8, characterized in that: Also includes: Determining a sub-cell interval in the power battery system that is in a thermal runaway state; Based on the sub-cell interval in the thermal runaway state, the first switch unit is controlled to be connected to a corresponding port of the sub-cell interval in the power battery system that is not in the thermal runaway state.

10. The control method according to claim 8, characterized in that: The controlling the second conversion module to convert the high voltage provided by the power battery system into a low voltage also includes: Get the vehicle running status; Based on the vehicle running state, it is determined that the vehicle is in a power-on completion state, and the second switch unit is controlled to be turned on to control the second DCDC conversion module to convert the high voltage provided by the power battery system into a low voltage.

11. The control method according to claim 10, characterized in that: Also includes: Determining that the vehicle is in a power-off state or in a power-on process based on the vehicle operating state, controlling the second switch unit to be turned off so that the second DCDC conversion module stops converting the high voltage provided by the power battery system into a low voltage.

12. A vehicle, characterized in that: Comprising a vehicle power supply system as described in any one of claims 1-7.

Images