Low-voltage power supply systems and vehicles

Abstract

This disclosure provides a low-voltage power supply system and a vehicle, belonging to the automotive field. In this disclosure, the low-voltage power supply system provides two low-voltage batteries. When one low-voltage battery fails, the other low-voltage battery can be used to power the low-voltage loads on the vehicle, thereby maintaining the normal operation of the various low-voltage loads and improving the reliability of vehicle operation.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of automobiles, and in particular, to a low-voltage power supply system and a vehicle. BACKGROUND

[0002] A low-voltage storage battery is an essential component of an automobile, and is used to supply power to various low-voltage loads (such as audio playback devices, automobile lights, various controllers, and the like) on the vehicle. Generally, a low-voltage storage battery is installed on a vehicle, and when the low-voltage storage battery fails, the various low-voltage loads on the vehicle cannot work normally, resulting in the vehicle being unable to be used normally. SUMMARY

[0003] Embodiments of the present disclosure provide a low-voltage power supply system and a vehicle, which can solve the technical problems in the related art. The technical solutions are as follows:

[0004] In a first aspect, embodiments of the present disclosure provide a low-voltage power supply system, which is applied to a vehicle, and includes a first low-voltage battery, a second low-voltage battery, a switching circuit, a low-voltage load, and a controller.

[0005] The switching circuit is electrically connected with the first low-voltage battery, the second low-voltage battery, the low-voltage load, and the controller, respectively.

[0006] The controller is configured to, in a state where the switching circuit communicates the first low-voltage battery with the low-voltage load and disconnects the second low-voltage battery from the low-voltage load, when detecting that the first low-voltage battery fails, control the switching circuit to communicate the second low-voltage battery with the low-voltage load and disconnect the first low-voltage battery from the low-voltage load.

[0007] In a possible implementation, the low-voltage power supply system further includes a direct-current high-low voltage converter, which is electrically connected with the first low-voltage battery, the second low-voltage battery, a high-voltage battery, and the controller, respectively.

[0008] The controller is further configured to:

[0009] In a case where the vehicle is in a powered-on state, control the high-voltage battery to charge the low-voltage battery, which is in communication with the low-voltage load, among the first low-voltage battery and the second low-voltage battery.

[0010] In a possible implementation, the controller is further configured to:

[0011] when it is detected that there is a low-voltage battery with an electric quantity lower than a first electric quantity threshold in the first low-voltage battery and the second low-voltage battery, control the high-voltage battery to charge the low-voltage battery with the electric quantity lower than the first electric quantity threshold;

[0012] when it is detected that the electric quantity of the charged low-voltage battery rises to a second electric quantity threshold, control the high-voltage battery to stop charging the charged low-voltage battery.

[0013] In a possible implementation, the controller is further configured to:

[0014] when it is detected that there is a low-voltage battery with an electric quantity lower than a first electric quantity threshold in the first low-voltage battery and the second low-voltage battery, determine a current time;

[0015] when the current time is within a target time period, control the high-voltage battery to charge the low-voltage battery with the electric quantity lower than the first electric quantity threshold, wherein a length of the target time period is a specified value, and the target time period is a time period with the highest average temperature in a day determined by historical statistical data;

[0016] when it is detected that the electric quantity of the charged low-voltage battery rises to a second electric quantity threshold, control the high-voltage battery to stop charging the charged low-voltage battery.

[0017] In a possible implementation, the low-voltage power supply system further includes a first temperature sensor and a second temperature sensor;

[0018] the first temperature sensor is attached to the first low-voltage battery and is configured to detect a temperature of the first low-voltage battery, the second temperature sensor is attached to the second low-voltage battery and is configured to detect a temperature of the second low-voltage battery, and the first temperature sensor and the second temperature sensor are respectively electrically connected to the controller;

[0019] the controller is further configured to:

[0020] when it is detected that there is a low-voltage battery with an electric quantity lower than a first electric quantity threshold in the first low-voltage battery and the second low-voltage battery, determine a temperature of the low-voltage battery by using a temperature sensor attached to the low-voltage battery with the electric quantity lower than the first electric quantity threshold;

[0021] when the temperature of the low-voltage battery with the electric quantity lower than the first electric quantity threshold is greater than a temperature threshold, control the high-voltage battery to charge the low-voltage battery with the electric quantity lower than the first electric quantity threshold;

[0022] When it is detected that the electric quantity of the charged low-voltage battery reaches a second electric quantity threshold, the high-voltage battery is controlled to stop charging the charged low-voltage battery.

[0023] In a possible implementation, the controller is further configured to:

[0024] acquire the charging times of the first low-voltage battery and the second low-voltage battery within a preset time period;

[0025] When the charging times of the first low-voltage battery within the preset time period reach a time threshold, it is determined that the first low-voltage battery is faulty, and when the charging times of the second low-voltage battery within the preset time period reach the time threshold, it is determined that the second low-voltage battery is faulty.

[0026] In a possible implementation, the low-voltage power supply system further comprises a heating assembly, the heating assembly has a first heat exchange pipeline, the first heat exchange pipeline of the heating assembly, a second heat exchange pipeline of the first low-voltage battery, and a third heat exchange pipeline of the second low-voltage battery are connected in series;

[0027] The heating assembly is electrically connected with the controller, and the heating assembly is configured to heat the liquid in the first heat exchange pipeline and drive the liquid in the first heat exchange pipeline to flow;

[0028] The controller is further configured to:

[0029] When the temperature of the low-voltage battery below the first electric quantity threshold detected by the temperature sensor of the low-voltage battery is less than or equal to the temperature threshold, the heating assembly is controlled to heat the liquid in the first heat exchange pipeline, and the heating assembly is controlled to drive the liquid in the first heat exchange pipeline to flow;

[0030] When the temperature of the low-voltage battery below the first electric quantity threshold detected by the temperature sensor of the low-voltage battery is greater than the temperature threshold, the heating assembly is controlled to stop heating the liquid in the first heat exchange pipeline, and the heating assembly is controlled to stop driving the liquid in the first heat exchange pipeline to flow.

[0031] In a second aspect, the embodiments of the present disclosure provide a vehicle, which comprises the low-voltage power supply system according to any one of the first aspect.

[0032] The present disclosure provides a low-voltage power supply system, which provides two low-voltage batteries, when one of the low-voltage batteries is faulty, the other low-voltage battery can be used to supply power to low-voltage loads on the vehicle, thereby maintaining the normal operation of the low-voltage loads on the vehicle, and the reliability of the vehicle operation can be improved.

[0033] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative labor.

[0035] Figure 1 is a schematic diagram of a low-voltage power supply system according to an embodiment of the present disclosure;

[0036] Figure 2 is a schematic diagram of a low-voltage power supply system according to an embodiment of the present disclosure;

[0037] Figure 3 is a schematic diagram of a low-voltage power supply system according to an embodiment of the present disclosure;

[0038] Figure 4 is a schematic diagram of a low-voltage power supply system according to an embodiment of the present disclosure;

[0039] Figure 5 is a flowchart of a method for charging a low-voltage battery according to an embodiment of the present disclosure;

[0040] Figure 6 is a flowchart of a method for charging a low-voltage battery according to an embodiment of the present disclosure;

[0041] Figure 7 is a flowchart of a method for charging a low-voltage battery according to an embodiment of the present disclosure;

[0042] Figure 8 is a flowchart of a method for charging a low-voltage battery according to an embodiment of the present disclosure;

[0043] Figure 9 is a flowchart of a method for detecting charging faults of a low-voltage battery according to an embodiment of the present disclosure.

[0044] LEGEND:

[0045] 1. first low-voltage battery;

[0046] 2. second low-voltage battery;

[0047] 3. switching circuit;

[0048] 4. low-voltage load;

[0049] 5. controller;

[0050] 6. High-low voltage DC converter

[0051] 7. High voltage battery

[0052] 8. First temperature sensor

[0053] 9. Second temperature sensor DETAILED DESCRIPTION

[0054] In order to make the objects, technical solutions and advantages of the present disclosure clearer, the following will further describe the embodiments of the present disclosure in detail with reference to the drawings.

[0055] Unless otherwise defined, technical terms or scientific terms used herein should be understood as having the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first", "second", "third" and similar terms used in the patent disclosure and claims of the present disclosure do not indicate any order, number or importance, but are only used to distinguish different components. Similarly, "one" or "a" and similar terms do not indicate a quantity limitation, but indicate the presence of at least one. "Include" or "contain" and similar terms mean that the elements or objects appearing before "include" or "contain" cover the elements or objects listed after "include" or "contain" and their equivalents, and do not exclude other elements or objects. "Connected" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships, and when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0056] Generally, there is only one low-voltage battery on a vehicle to supply power to various low-voltage loads on the vehicle. When the low-voltage battery fails, it cannot normally supply power to various low-voltage loads on the vehicle, thereby affecting the normal use of the vehicle. The embodiments of the present disclosure provide a low-voltage power supply system, which includes two low-voltage batteries. When one of the low-voltage batteries fails, the other low-voltage battery can be used to supply power to the low-voltage load, ensuring that each component on the vehicle can be used normally, and improving the reliability of the low-voltage power supply system on the vehicle.

[0057] The embodiments of the present disclosure provide a low-voltage power supply system, which can be applied to a vehicle. As shown in Figure 1 The low-voltage power supply system includes a first low-voltage battery 1, a second low-voltage battery 2, a switching circuit 3, a low-voltage load 3 and a controller 5, which are described in detail below.

[0058] I. First low-voltage battery 1

[0059] The first low-voltage battery 1 is a low-voltage storage battery used to power low-voltage loads on the vehicle. The voltage of the first low-voltage battery 1 can be 12V, but this embodiment of the present disclosure does not limit it. The first low-voltage battery can be a lithium battery. Compared with lead-lithium hybrid batteries, lithium batteries have a lower structural complexity, and compared with dual lead-acid batteries, lithium batteries are smaller in weight and volume, making them easier to install on the vehicle.

[0060] II. Second low-voltage battery 2

[0061] The second low-voltage battery 2 can be the same as or different from the first low-voltage battery 1, and this disclosure does not limit this. This disclosure provides a detailed description of the scheme using the example where both the first low-voltage battery 1 and the second low-voltage battery 2 are low-voltage lithium batteries.

[0062] III. Switching Circuit 3

[0063] Switching circuit 3 is electrically connected to the first low-voltage battery 1, the second low-voltage battery 2, and the low-voltage load 4, such as... Figure 1 As shown, the switching circuit 3 is used to connect or disconnect the first low-voltage battery 1 and the low-voltage load 3, and is also used to connect or disconnect the second low-voltage battery 2 and the low-voltage load 3. When the first low-voltage battery 1 and the low-voltage load 3 are connected, the first low-voltage battery 1 supplies power to the low-voltage load 3. When the second low-voltage battery 2 and the low-voltage load 3 are connected, the second low-voltage battery 2 supplies power to the low-voltage load 3.

[0064] IV. Low-voltage load 4

[0065] Devices powered by low-voltage batteries in a car can be called low-voltage loads. There are many types of low-voltage loads in a vehicle, such as windows, power seats, horns, lighting equipment, dashboards, audio entertainment systems, and so on.

[0066] V. Controller 5

[0067] Controller 5 can be electrically connected to switching circuit 3, and controller 5 can control switching circuit 3 based on certain principles. Controller 5 can be a vehicle domain controller, or other controllers on the vehicle that can know the overall status of the vehicle; this embodiment does not limit this. Controller 5 can monitor the status of each low-voltage battery. Specifically, the low-voltage battery monitoring system (LBMS) can know the status of the batteries and transmit it to controller 5 via the Controller Area Network (CAN) bus. Therefore, controller 5 can control switching circuit 3 based on the battery status.

[0068] The following section introduces some optional structural features of low-voltage power supply systems:

[0069] Structural features: 1. Low-voltage power supply systems may also include DC-DC converters (DCDC) 6.

[0070] The DC-DC high-low voltage converter 6 is a device that can convert high-voltage DC power into low-voltage DC power. This device can convert the high-voltage DC power stored inside the vehicle's high-voltage battery (i.e., the vehicle's power battery) into low-voltage DC power. For example... Figure 2 As shown, the DC-DC high-low voltage converter 6 is electrically connected to the first low-voltage battery 1, the second low-voltage battery 2, the high-voltage battery 7, and the controller 5, respectively. The controller 5 can control the DC-DC high-low voltage converter 6 to charge the two batteries based on the states of the first low-voltage battery 1 and the second low-voltage battery 2. When the vehicle is powered on normally, the DC-DC high-low voltage converter 6 continuously converts the high voltage of the high-voltage battery 7 to low voltage, thereby continuously supplying power to the low-voltage batteries. When the vehicle is in sleep mode, the DC-DC high-low voltage converter 6 can charge the low-voltage batteries whose charge is below the charge threshold to prevent the battery from being depleted due to excessive power consumption during sleep mode.

[0071] Structural feature 2: The low-voltage power supply system may also include a DC-DC converter (DCDC) 6, a first temperature sensor 8, and a second temperature sensor 9.

[0072] Temperature sensors are devices used in vehicles to monitor battery temperature. They can be mounted on the surface of the low-voltage battery, in close contact with it, to monitor temperature changes in real time. A first temperature sensor 8 can be used to monitor the temperature of a first low-voltage battery 1, and a second temperature sensor 9 can be used to monitor the temperature of a second low-voltage battery 2. For example... Figure 3 As shown, the first temperature sensor 8 and the second temperature sensor 9 can be electrically connected to the controller 5, respectively. Furthermore, the first temperature sensor 8 and the second temperature sensor 9 send the battery temperature to the controller 5.

[0073] Structural feature three: The low-voltage power supply system may also include a DC-DC converter (DCDC) 6, a first temperature sensor 8, a second temperature sensor 9, and a heating component 10.

[0074] The heating assembly 10 includes a first heat exchange pipe through which a fluid flows. The fluid can be water or other fluids, and this embodiment does not limit the specific type of fluid. The heating assembly 10 includes a heating device, such as a heating wire, for heating the liquid in the first heat exchange pipe.

[0075] like Figure 4As shown in FIG. 1, the first heat exchange pipe of the heating assembly 10, the second heat exchange pipe of the first low-voltage battery 1, and the third heat exchange pipe of the second low-voltage battery 2 are connected in series. The heat exchange pipes in the low-voltage batteries can be arranged in the battery compartment of the low-voltage batteries or arranged elsewhere, which is not limited in the embodiments of the present disclosure. The heat carried by the fluid in the heat exchange pipes is used to adjust the temperature of the low-voltage batteries.

[0076] The embodiments of the present disclosure also provide a method for low-voltage power supply of a vehicle, which can be applied to the low-voltage power supply system described above. When one of the low-voltage batteries fails, another low-voltage battery is used to supply power to the low-voltage load. The method will be described in detail as follows:

[0077] When the switching circuit connects the first low-voltage battery with the low-voltage load and disconnects the second low-voltage battery from the low-voltage load, and when the first low-voltage battery is detected to fail, the switching circuit is controlled to connect the second low-voltage battery with the low-voltage load and disconnect the first low-voltage battery from the low-voltage load.

[0078] The controller can control the switching circuit to connect the first low-voltage battery with the low-voltage load and disconnect the second low-voltage battery from the low-voltage load in advance. The controller is electrically connected with the DBMS and can know whether the low-voltage battery is working normally. Specifically, the DBMS can monitor the current and voltage of the low-voltage battery to know whether the low-voltage battery fails. There are many reasons for the failure of the low-voltage battery, for example, the internal short circuit of the battery, the overcharging of the battery, and the like, which will not be described in detail in the embodiments of the present disclosure. When the DBMS knows that the first low-voltage battery fails, the controller is informed of the failure message, and then the controller controls the switching circuit to connect the second low-voltage battery with the low-voltage load and disconnect the first low-voltage battery from the low-voltage load.

[0079] The mechanism of the low-voltage power supply system in the two scenarios of the normal power-on of the vehicle and the hibernation of the vehicle will be described in detail as follows.

[0080] First, the case that the vehicle is in the power-on state is introduced. The corresponding steps are that when the vehicle is in the power-on state, the controller controls the high-voltage battery to continuously charge the first low-voltage battery, and the first low-voltage battery is the low-voltage battery currently connected with the low-voltage load. When the first low-voltage battery is detected to fail, the switching circuit is controlled to connect another low-voltage battery with the low-voltage load and disconnect the low-voltage battery from the low-voltage load. At this time, the controller controls the high-voltage battery to stop charging the first low-voltage battery and continuously charge the second low-voltage battery.

[0081] Next, the method for charging the low-voltage battery when the vehicle is in the hibernation state is introduced. The corresponding process is as shown in FIG. 2, which includes the following steps. Figure 5

[0082] ​Step 501, in the case that the vehicle is in the hibernation state, when the controller detects that there is a low-voltage battery with an electric quantity lower than the first electric quantity threshold in the first low-voltage battery and the second low-voltage battery, the high-voltage battery is controlled to charge the low-voltage battery with the electric quantity lower than the first electric quantity threshold.

[0083] The first electric quantity threshold can be a percentage, for example, 20% or 10%, etc., which can be set by the relevant technical personnel according to the actual situation, and the embodiments of the present disclosure do not limit this. The controller can know the remaining electric quantity of the two low-voltage batteries through the LBMS, and then control the DCDC to charge the low-voltage battery with the electric quantity lower than the first electric quantity threshold. When the remaining electric quantities of the two low-voltage batteries are both lower than the first electric quantity threshold, the controller can control the DCDC to charge the two low-voltage batteries at the same time, or can charge them respectively, and the embodiments of the present disclosure do not limit this.

[0084] Optionally, before charging the low-voltage battery, the controller can determine whether the battery to be charged is a faulty battery, and if it is a faulty battery, it will not be charged. The controller can also obtain the electric quantity of the high-voltage battery, and when the electric quantity of the high-voltage battery is too low, the controller will not perform the charging operation.

[0085] Step 502, when the controller detects that the electric quantity of the charged low-voltage battery rises to the second electric quantity threshold, the high-voltage battery is controlled to stop charging the low-voltage battery.

[0086] The second electric quantity threshold can be a percentage, for example, 90% or 95%, etc., which can be set by the relevant technical personnel according to the actual situation. The embodiments of the present disclosure do not limit this.

[0087] The above-mentioned operation steps of the process are used to charge the low-voltage battery. When the electric quantity of the low-voltage battery is detected to be less than the first electric quantity threshold, the low-voltage battery is charged to ensure that the low-voltage battery can be timely recharged, thereby maintaining the normal work of part of the controller when the vehicle is in hibernation.

[0088] When the temperature of the low-voltage battery is too low, the efficiency of the high-voltage battery charging the low-voltage battery is low, so the time period with the highest temperature in a day can be selected to charge the low-voltage battery. The corresponding process is as shown in Figure 6 , including the following steps:

[0089] Step 601, in the case that the vehicle is in the hibernation state, when the controller detects that there is a low-voltage battery with an electric quantity lower than the first electric quantity threshold in the first low-voltage battery and the second low-voltage battery, the current time is determined.

[0090] The current time is the time when the low-voltage battery with the electric quantity lower than the first electric quantity threshold is detected.

[0091] Step 602, when the time is in the target time period, the controller controls the high-voltage battery to charge the low-voltage battery with the electric quantity lower than the first electric quantity threshold.

[0092] The length of the target time period is a specified value, and the target time period is a time period with the highest average temperature in a day determined by historical statistical data.

[0093] Specifically, the time period can be divided in advance, for example, the time period can be two hours. Then the temperature of multiple time points of each day in a certain region for one year is obtained, and for a certain time period of a day, the average temperature of the temperatures of multiple time points of the day included in the time period is taken as the temperature of the time period of the day. Then for each time period, the average temperature of the time period in a year is taken as the temperature of the time period. In this way, each time period has a corresponding temperature. The time period with the highest temperature can be taken as the target time period.

[0094] Optionally, considering that the time period with the highest temperature in a day can be different for each province, the above operation can be performed for each province, so that each province corresponds to a target time period. The vehicle corresponds to different target time periods for charging in different provinces.

[0095] Step 603, when it is detected that the electric quantity of the charged low-voltage battery rises to the second electric quantity threshold, the high-voltage battery stops charging the charged low-voltage battery.

[0096] The above process is used to charge the low-voltage battery, and the low-voltage battery is charged only at the most appropriate temperature in a day, which can ensure the charging efficiency of the low-voltage battery to a certain extent. Because when the battery temperature is too low, due to the structural characteristics of the battery itself, even if the charging power of the high-voltage battery to the low-voltage battery is high, the charging rate of the battery is small, which causes waste of electric quantity. In an extreme case, since the time taken for the low-voltage battery to reach the second electric quantity threshold is very long, the high-voltage battery may continue to supply power to the low-voltage battery and eventually consume the electric quantity of the high-voltage battery. This causes great waste of electric quantity, and when the vehicle owner wants to power on the vehicle again, he finds that the electric quantity of the high-voltage battery is very low, which affects the normal use of the vehicle. Therefore, the low-voltage battery can be charged at a time period with a high temperature in a day, which ensures the charging efficiency of the low-voltage battery and prevents excessive waste of the electric quantity of the high-voltage battery.

[0097] In addition, the charging of the low-voltage battery can be determined not by the time period but by the temperature of the low-voltage battery. When the temperature of the low-voltage battery reaches a temperature threshold, the charging is started. If the low-voltage battery does not reach the temperature threshold, the low-voltage battery to be charged can be heated by a heating component, and the charging is started when the temperature of the low-voltage battery reaches the temperature threshold. Correspondingly, the process is as shown in Figure 7 ​

[0098] Step 701, in the case where the vehicle is in a dormant state, when the controller detects that there is a low-voltage battery with an electric quantity lower than the first electric quantity threshold in the first low-voltage battery and the second low-voltage battery, the temperature of the low-voltage battery is determined by the corresponding temperature sensor.

[0099] Step 702, when the temperature of the low-voltage battery is greater than the temperature threshold, the controller controls the high-voltage battery to charge the low-voltage battery.

[0100] The temperature threshold can be set by the relevant technical personnel according to the actual situation, and the embodiment of the present disclosure does not limit it.

[0101] Step 703, when the temperature of the low-voltage battery is less than the temperature threshold, the controller controls the heating assembly to heat the low-voltage battery until the temperature of the low-voltage battery reaches the temperature threshold and then charges the low-voltage battery.

[0102] When the temperature of the low-voltage battery detected by the temperature sensor is less than or equal to the temperature threshold, the heating assembly is controlled to heat the liquid in the first heat exchange pipeline, and the heating assembly is controlled to drive the liquid in the first heat exchange pipeline to flow; when the temperature of the low-voltage battery detected by the temperature sensor is greater than the temperature threshold, the heating assembly is controlled to stop heating the liquid in the first heat exchange pipeline, and the heating assembly is controlled to stop driving the liquid in the first heat exchange pipeline to flow.

[0103] Optionally, the controller can control the heating assembly to drive the liquid in the first heat exchange pipeline to flow at a speed, and the faster the liquid flows, the faster the low-voltage battery is heated. A corresponding relationship between the temperature range and the flow rate can be established in advance, and different temperature ranges correspond to different flow rates, and the higher the temperature, the lower the flow rate.

[0104] Step 704, when it is detected that the electric quantity of the charged low-voltage battery reaches the second electric quantity threshold, the high-voltage battery stops charging the charged low-voltage battery.

[0105] The above operation process is used to charge the low-voltage battery, which can heat the low-voltage battery when the battery temperature is low, and then ensure a high charging rate when charging the low-voltage battery, and does not waste too much electric quantity of the high-voltage battery.

[0106] For the above case, considering that the electric energy needed for heating the heating assembly comes from the low-voltage battery, therefore, whether to charge the low-voltage battery or heat the low-voltage battery can be determined based on the remaining electric quantity of the low-voltage battery, and the corresponding process is as shown in Figure 8 , including the following steps:

[0107] Step 801, in the case where the vehicle is in a dormant state, the temperature of the low-voltage battery and the electric quantity of the low-voltage battery are determined.

[0108] Step 802, when it is detected that there is a low-voltage battery with an electric quantity lower than a third electric quantity threshold in the two low-voltage batteries, the high-voltage battery is controlled to charge the low-voltage battery lower than the third electric quantity threshold until the third electric quantity threshold is reached.

[0109] The third electric quantity threshold can be set by the related technicians according to the actual situation, and the embodiments of the present disclosure do not limit this, for example, the third electric quantity threshold can be 10%. When the remaining electric quantity of the low-voltage battery is less than the third threshold, it indicates that the remaining electric quantity of the current low-voltage battery is very low, and the low-voltage battery is preferentially charged without using the electric quantity of the low-voltage battery to heat the low-voltage battery.

[0110] When the electric quantity of the low-voltage battery reaches the third electric quantity threshold, the charging can continue according to the operation steps of step 804.

[0111] Step 803, when it is detected that there is a low-voltage battery with an electric quantity higher than the third electric quantity threshold and lower than a fourth electric quantity threshold in the two low-voltage batteries, and the temperature of the low-voltage battery is less than the temperature threshold, the high-voltage battery is controlled to charge the low-voltage battery, the heating assembly is controlled to heat the liquid in the first heat exchange pipeline, and the heating assembly is controlled to drive the liquid in the first heat exchange pipeline to flow until the fourth electric quantity threshold is reached.

[0112] Wherein, the fourth electric quantity threshold is greater than the third electric quantity threshold, and the related technicians can set it according to the actual situation, and the embodiments of the present disclosure do not limit this, for example, when the third electric quantity threshold is 10%, the fourth electric quantity threshold can be set to 20%.

[0113] By setting the charging power of the high-low battery to the low-voltage battery and the heating power of the low-voltage battery, the power consumption speed of the low-voltage battery is less than the charging speed, and then the electric quantity of the battery can slowly rise, and with the growth of time, the temperature of the battery is closer and closer to the temperature suitable for charging the battery, and then the charging speed of the battery will be faster and faster, until the electric quantity of the battery reaches the fourth electric quantity threshold. If the temperature of the battery being charged reaches the temperature threshold before reaching the fourth electric quantity threshold, the heating assembly is controlled to stop heating the liquid in the first heat exchange pipeline, and the heating assembly is controlled to stop driving the liquid in the first heat exchange pipeline to flow. When the electric quantity of the battery reaches the fourth electric quantity threshold, the charging can continue according to the operation steps of step 805.

[0114] Step 804, when it is detected that there is a low-voltage battery with an electric quantity higher than the fourth electric quantity threshold and lower than a fifth electric quantity threshold in the two low-voltage batteries, and the temperature of the low-voltage battery is less than the temperature threshold, the heating assembly is controlled to heat the liquid in the first heat exchange pipeline, and the heating assembly is controlled to drive the liquid in the first heat exchange pipeline to flow until the second electric quantity threshold is reached.

[0115] The fifth electric quantity threshold is greater than the fourth electric quantity threshold, and a person skilled in the art can set it according to actual conditions, and the embodiment of the present disclosure does not limit it, for example, the fifth electric quantity threshold can be 30%. The fifth electric quantity threshold indicates that the low-voltage battery needs to be charged when it is lower than the fifth electric quantity threshold. The fifth electric quantity threshold can be the same as the first electric quantity threshold, or it can be different, and the embodiment of the present disclosure does not limit it.

[0116] When the electric quantity threshold of the low-voltage battery is between the fourth electric quantity threshold and the fifth electric quantity threshold, and when the temperature of the low-voltage battery is lower than the temperature threshold, the low-voltage battery can be normally heated without considering the consumption of the heating assembly to the electric quantity of the low-voltage battery.

[0117] Step 805, when it is detected that the electric quantity of the low-voltage battery being charged reaches the second electric quantity threshold, the high-voltage battery is controlled to stop charging the low-voltage battery being charged.

[0118] The above operation process is used to charge the low-voltage battery, which takes into account the discharge and charging rate of the low-voltage battery, and thus the low-voltage battery can be better charged.

[0119] Optionally, even if the remaining electric quantity of the low-voltage battery is not lower than the electric quantity threshold that needs to be charged, when it is detected that the temperature of the low-voltage battery is too low, the low-voltage battery can be heated to ensure normal operation of the low-voltage battery.

[0120] Optionally, the remaining electric quantity of the high-voltage battery can be obtained before charging the low-voltage battery, and when the remaining electric quantity of the high-voltage battery is too low, the high-voltage battery is not controlled to charge the low-voltage battery.

[0121] Optionally, in the state of hibernation of the vehicle, the charging frequency of the vehicle can be counted, and whether the low-voltage battery fails can be determined by counting the charging frequency of the low-voltage battery. When the charging frequency of the low-voltage battery is too high and exceeds the frequency threshold, it can be determined that the low-voltage battery fails. Then the low-voltage battery that fails is locked, the low-voltage load is not powered by the low-voltage battery, and the low-voltage battery is not powered. The corresponding process can be as shown in Figure 9 The process can include the following steps:

[0122] Step 901, obtaining the charging frequency of the first low-voltage battery and the second low-voltage battery within a preset time period.

[0123] The preset time period can be determined by a person skilled in the art according to actual conditions, and the embodiment of the present disclosure does not limit it, for example, the preset time period can be 6 hours, or 8 hours, etc.

[0124] At step 902, when the number of times of charging of the first low-voltage battery in the preset time length reaches a number threshold, it is determined that the first low-voltage battery is faulty, and when the number of times of charging of the second low-voltage battery in the preset time length reaches the number threshold, it is determined that the second low-voltage battery is faulty.

[0125] The number threshold can be determined by a person skilled in the art according to actual conditions, and the embodiments of the present disclosure do not limit this, for example, when the preset time length is 6 hours, the number threshold can be 50 times. When the number of times of charging of the low-voltage battery in the preset time length is greater than or equal to the number threshold, it is determined that the low-voltage battery is faulty. The fault of the low-voltage battery can be due to the internal failure of the low-voltage battery, or the low-voltage battery is leaking, etc.

[0126] At step 903, the low-voltage battery determined to be the faulty battery is locked, and another low-voltage battery is used to supply power to the low-voltage load.

[0127] When it is determined that the low-voltage battery is faulty, the low-voltage battery can be locked, and another low-voltage battery is used to supply power to the low-voltage load. Specifically, the switching circuit can be controlled to disconnect the faulty low-voltage battery from the low-voltage load and connect the low-voltage battery that has not failed to the low-voltage load. Furthermore, the DCDC is notified that the faulty low-voltage battery will not be charged regardless of the state of the faulty low-voltage battery.

[0128] In this way, the number of times of charging of the low-voltage battery can be used to learn that the low-voltage battery is faulty in a timely manner, and the low-voltage battery is then locked, so that the faulty low-voltage battery is not used to supply power to the low-voltage load, and the faulty low-voltage battery will not be charged when the power of the faulty low-voltage battery is low. When the vehicle is in hibernation, the waste of the power of the high-voltage battery on the vehicle can be avoided.

[0129] The present disclosure provides a low-voltage power supply system, which provides two low-voltage batteries, and when one of the low-voltage batteries fails, another low-voltage battery can be used to supply power to the low-voltage load on the vehicle, thereby maintaining the normal operation of each low-voltage load of the vehicle and improving the reliability of the operation of the vehicle.

[0130] The embodiments of the present disclosure provide an electric vehicle, which includes the low-voltage power supply system described above. The electric vehicle uses the low-voltage power supply system described above to supply power to each low-voltage load on the vehicle, and the low-voltage power supply system can work when the electric vehicle starts, when the electric vehicle normally drives, and when the electric vehicle hibernates.

[0131] The above only describes optional embodiments of the present disclosure and does not limit the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A low voltage power supply system, characterized in that The low-voltage power supply system is applied to a vehicle, and comprises a first low-voltage battery (1), a second low-voltage battery (2), a switching circuit (3), a low-voltage load (4), a DC high-low voltage converter (6), a first temperature sensor (8), a second temperature sensor (9) and a controller (5); The switching circuit (3) is electrically connected with the first low-voltage battery (1), the second low-voltage battery (2), the low-voltage load (4) and the controller (5) respectively; The DC high-low voltage converter (6) is electrically connected with the first low-voltage battery (1), the second low-voltage battery (2), a high-voltage battery (7) and the controller (5) respectively; The first temperature sensor (8) is attached to the first low-voltage battery (1) and used for detecting the temperature of the first low-voltage battery (1), the second temperature sensor (9) is attached to the second low-voltage battery (2) and used for detecting the temperature of the second low-voltage battery (2), and the first temperature sensor (8) and the second temperature sensor (9) are electrically connected with the controller (5) respectively; The controller (5) is configured to: when detecting that the first low-voltage battery (1) is faulty in a state where the switching circuit (3) connects the first low-voltage battery (1) with the low-voltage load (4) and disconnects the second low-voltage battery (2) from the low-voltage load (4), control the switching circuit (3) to connect the second low-voltage battery (2) with the low-voltage load (4) and disconnect the first low-voltage battery (1) from the low-voltage load (4); In a case where the vehicle is in a powered-on state, control the high-voltage battery (7) to charge the low-voltage battery, which is connected with the low-voltage load (4), among the first low-voltage battery (1) and the second low-voltage battery (2); In a case where the vehicle is in a sleep state, when detecting that there is a low-voltage battery with an electric quantity lower than a first electric quantity threshold in the first low-voltage battery (1) and the second low-voltage battery (2), determine the temperature of the low-voltage battery through the temperature sensor attached to the low-voltage battery; when the temperature of the low-voltage battery with the electric quantity lower than the first electric quantity threshold is greater than a temperature threshold, control the high-voltage battery (7) to charge the low-voltage battery; and when detecting that the electric quantity of the charged low-voltage battery reaches a second electric quantity threshold, control the high-voltage battery (7) to stop charging the low-voltage battery.

2. The low voltage power supply system of claim 1, wherein, The controller (5) is further configured to: In a case where the vehicle is in a sleep state, when detecting that there is a low-voltage battery with an electric quantity lower than a first electric quantity threshold in the first low-voltage battery (1) and the second low-voltage battery (2), determine a current time; When the current time is within a target time period, control the high-voltage battery (7) to charge the low-voltage battery with the electric quantity lower than the first electric quantity threshold, wherein the length of the target time period is a specified value, and the target time period is a time period with the highest average temperature in a day determined through historical statistical data. When detecting that the electric quantity of the charged low-voltage battery rises to a second electric quantity threshold, the high-voltage battery (7) is controlled to stop charging the charged low-voltage battery.

3. The low voltage power supply system of claim 1, wherein, The controller (5) is further configured to: acquire the charging times of the first low-voltage battery (1) and the second low-voltage battery (2) within a preset time period; when the charging times of the first low-voltage battery (1) within the preset time period reaches a times threshold, determine that the first low-voltage battery (1) is faulty, and when the charging times of the second low-voltage battery (2) within the preset time period reaches the times threshold, determine that the second low-voltage battery (2) is faulty.

4. The low voltage power supply system of claim 3, wherein, The controller (5) is further configured to: after determining the faulty low-voltage battery, control the high-voltage battery (7) to stop charging the faulty low-voltage battery.

5. The low voltage power supply system of claim 1, wherein, The controller (5) is further configured to: acquire the remaining electric quantity of the high-voltage battery (7); when the remaining electric quantity of the high-voltage battery (7) is lower than a third electric quantity threshold, control the high-voltage battery (7) to stop charging the low-voltage battery.

6. The low voltage power supply system of claim 1, wherein, The first low-voltage battery (1) and the second low-voltage battery (2) are both lithium batteries.

7. A vehicle characterized by comprising: The vehicle comprises the low-voltage power supply system according to any one of claims 1 to 6.

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