Battery charging method and vehicle electrical system

Abstract

The application provides a battery charging method and a vehicle electrical system, which can meet safe and efficient charging of a low SOC power battery by a charging pile in a low temperature environment. The battery charging control method is applied to a vehicle electrical system, which comprises a current control unit including a semiconductor device. The method comprises: when the temperature of the battery is lower than a first preset temperature, controlling the current control unit to be in a first state, wherein the first state comprises a state in which the semiconductor device is reversely connected to a circuit; requesting to send a first charging request, the first charging request comprising a first charging current; when the temperature of the battery reaches the first preset temperature, controlling the current control unit to be in a second state, the second state comprising a state in which the semiconductor device is disconnected from the circuit or a state in which the semiconductor device is connected to the circuit in a forward direction; and requesting to send a second charging request, the second charging request comprising a second charging current, and the battery is charged at the second charging current.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery charging method and a vehicle electrical system. Background Technology

[0002] With the rapid development of new energy batteries, electric vehicles have become a new direction for the future development of the automotive industry. As power battery technology matures, users have higher demands for charging speed and safety. However, currently used charging stations cannot safely and efficiently charge power batteries with low state of charge (SOC) in low-temperature environments, limiting the functionality and application of charging stations. Summary of the Invention

[0003] This application provides a battery charging method and a vehicle electrical system that can meet the requirements of charging piles for safe and efficient charging of low-SOC power batteries in low-temperature environments.

[0004] In a first aspect, this application provides a battery charging control method applied to a vehicle electrical system. The vehicle electrical system includes a current control unit, which includes a semiconductor device. One end of the current control unit is connected to a battery, and the other end is connected to a charging power source. The battery charging control method includes: when the battery temperature is lower than a first preset temperature, controlling the current control unit to be in a first state, wherein the first state includes a state where the semiconductor device is reverse-connected to a circuit; sending a first charging request, the first charging request including a first charging current, which is the current required to heat the battery to the first preset temperature; when the battery temperature reaches the first preset temperature, controlling the current control unit to be in a second state, wherein the second state includes a state where the semiconductor device is disconnected from a circuit or a state where the semiconductor device is forward-connected to a circuit; and sending a second charging request, the second charging request including a second charging current, with the battery being charged using the second charging current.

[0005] This application provides a battery charging method that switches the operating state of the current control unit to a first state or a second state based on the battery temperature. When the battery temperature is below a first preset temperature, the current control unit is in the first state, and the semiconductor device is connected to the circuit in reverse. In this state, the current control unit blocks current flow, the charging power supply stops charging the battery, and the charging power supply forms a loop with the battery heating module, supplying power to the heating module to heat the battery. When the battery temperature reaches the first preset temperature, the current control unit is in the second state, and the semiconductor device is either connected to the circuit in reverse or forward. In this state, the current control unit allows current flow, the charging power supply forms a loop with the battery and the current control unit, charging the battery, and the connection between the charging power supply and the battery heating module is disconnected, stopping power supply to the heating module. This allows for the request of charging current for heating without altering the communication protocol during low-temperature charging, effectively preventing the charging current from flowing into the battery and causing damage. After heating to room temperature or the battery's required operating temperature, the current control unit can be switched for regular fast charging, thus enabling safe and efficient low-temperature charging of low-temperature, low-SOC batteries.

[0006] In one possible embodiment, when the battery temperature reaches a first preset temperature, controlling the current control unit to be in a second state includes: when the battery temperature reaches the first preset temperature, sending a first charging request, the first charging request including: a first charging current of 0.

[0007] In the above embodiments, when the battery has been heated to a first preset temperature, a request is made for the first charging current to be 0, and then the current control unit is switched to a second state. That is, when switching the operating state of the current control unit, the charging current used for heating is reduced to 0. This prevents current from flowing into the battery during the switching of the current control unit's operating state and causing battery damage, further ensuring the safety of low-temperature charging of the battery.

[0008] In one possible embodiment, the current control unit includes a semiconductor device and a first relay. When the battery temperature is lower than a first preset temperature, the current control unit is controlled to be in a first state, including: when the battery temperature is lower than the preset temperature, the first relay is disconnected. One end of the first relay is connected to the battery, and the other end of the first relay is connected to the charging power supply. The semiconductor device is connected in parallel with the first relay.

[0009] In one possible embodiment, the current control unit includes a semiconductor device and a first relay. When the battery temperature reaches a first preset temperature, the current control unit is controlled to be in a second state, including: when the battery temperature reaches the first preset temperature, controlling the first relay to be turned on, wherein one end of the first relay is connected to the battery, the other end of the first relay is connected to the charging power supply, and the semiconductor device is connected in parallel with the first relay.

[0010] In the above embodiments, the current control unit includes a first relay and a semiconductor device, with the first relay and the semiconductor device connected in parallel. Disconnecting the first relay reverses the circuit connection of the semiconductor device, placing the current control unit in a first state; turning on the first relay bypasses the semiconductor device, placing the current control unit in a second state. By controlling the on / off state of the first relay, the semiconductor device can be connected to and disconnected from the circuit, switching the operating state of the current control unit.

[0011] In one possible embodiment, the current control unit includes a bidirectional semiconductor device. When the battery temperature reaches a first preset temperature, the current control unit is controlled to be in a second state, including: when the battery temperature reaches the first preset temperature, the bidirectional semiconductor device is controlled to switch, so that the bidirectional semiconductor device is connected to the circuit in the forward direction.

[0012] In the above embodiments, the current control unit includes a bidirectional semiconductor device. By controlling the switching of the bidirectional semiconductor device, the circuit can be connected in reverse when the battery temperature is lower than the first preset temperature, and in the forward direction when the battery temperature reaches the first preset temperature. This saves the relay in the current control unit, making the circuit connection and control simpler, thereby ensuring quick and efficient switching of the current control unit's working state.

[0013] Secondly, this application provides a vehicle electrical system, including: a current control unit, which includes a semiconductor device, one end of which is connected to a battery and the other end to a charging power supply; a control module, which controls the current control unit to be in a first state when the battery temperature is lower than a first preset temperature, wherein the first state includes a state in which the semiconductor device is reverse-connected to a circuit; a communication module, which sends a first charging request, the first charging request including a first charging current, the first charging current being the current required to heat the battery to the first preset temperature; the control module is also used to control the current control unit to be in a second state when the battery temperature reaches the first preset temperature, wherein the second state includes a state in which the semiconductor device is disconnected from a circuit or a state in which the semiconductor device is forward-connected to a circuit; the communication module is also used to send a second charging request, the second charging request including a second charging current, wherein the battery is charged with the second charging current.

[0014] The above embodiments provide a vehicle electrical system that uses a current control unit to adjust its operation based on the battery temperature, placing it in either a first or second state. When the battery temperature is below a first preset temperature, the current control unit is in the first state, with the semiconductor device connected in reverse to the circuit. In this state, the current control unit blocks current flow, and the charging power supply forms a loop with the battery heating module, supplying power to the heating module to heat the battery. When the battery temperature reaches the first preset temperature, the current control unit is in the second state, with the semiconductor device either disconnected from the circuit or connected in forward mode. In this state, the current control unit allows current flow, and the charging power supply forms a loop with the power battery and the current control unit to perform normal charging of the power battery. The connection between the charging power supply and the battery heating module is disconnected, stopping power supply to the heating module. This allows for the request of charging current for heating without altering the communication protocol during low-temperature charging, effectively preventing the charging current from flowing into the power battery and causing damage. After heating to room temperature or the battery's required operating temperature, normal fast charging can be performed by switching the current control unit, enabling safe and efficient low-temperature charging of low-temperature, low-SOC batteries using charging piles.

[0015] In one possible embodiment, the communication module is further configured to: send a first charging request when the battery temperature reaches a first preset temperature, the first charging request including: a first charging current of 0.

[0016] In the above embodiments, when the battery has been heated to the first preset temperature, the communication module requests that the first charging current be 0. The control module then controls the current control unit to enter the second state, that is, when switching the working state of the current control unit, the charging current is reduced to 0. This prevents current from flowing into the battery and causing battery damage during the switching of the current control unit's working state, further ensuring the safety of low-temperature charging of the battery.

[0017] Thirdly, this application provides a vehicle electrical system, including a battery and a current control unit. The current control unit includes a first relay and a semiconductor device. One end of the first relay is connected to the battery, and the other end of the first relay is connected to a charging power supply. The semiconductor device is connected in parallel with the first relay. Specifically, when the battery temperature is below a first preset temperature, the current control unit is in a first state, in which the first relay is disconnected; when the battery temperature reaches the first preset temperature, the current control unit is in a second state, in which the first relay is turned on.

[0018] In one possible embodiment, the current control unit includes: a first relay, a semiconductor device, and a second relay. One end of the first relay is connected to the battery, and the other end is connected to a charging power supply. The semiconductor device is connected in parallel with the first relay. The second relay is connected to the branch where the semiconductor device is located. When the battery temperature is below a first preset temperature, the current control unit is in a first state, in which the first relay is off and the second relay is on. When the battery temperature reaches the first preset temperature, the current control unit is in a second state, in which the first relay is on and the second relay is off.

[0019] In the above embodiments, the current control unit includes a first relay and a semiconductor device, and also includes a second relay connected in series with the semiconductor device in the branch where the semiconductor device is located. This second relay controls the semiconductor device's connection to and connection from the circuit. Using both the first relay connected in parallel with the semiconductor device and the second relay connected in series with the semiconductor device to simultaneously control the semiconductor device's connection to and connection from the circuit improves circuit safety. When a relay in one branch fails or malfunctions, the relay in the other branch can continue to operate, ensuring the switching between the semiconductor device's connection to and connection from the circuit, thus improving the reliability of the electrical system.

[0020] Fourthly, this application provides a battery management system, including a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to invoke the computer program to execute the method of any possible embodiment of the first aspect described above.

[0021] Fifthly, this application provides a storage medium for storing a computer program for performing the methods of any possible embodiments of the first aspect described above.

[0022] Sixthly, this application provides a vehicle including a vehicle electrical system comprising any possible embodiments of the first and second aspects described above. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a charging system disclosed in one embodiment of this application;

[0025] Figure 2 This is a schematic diagram of the connection between a vehicle electrical system and a charging power supply, as disclosed in an embodiment of this application.

[0026] Figure 3 This is a schematic diagram of another vehicle electrical system connected to a charging power supply according to an embodiment of this application;

[0027] Figure 4 This is a schematic diagram of the connection between a vehicle electrical system and a charging power supply, as disclosed in an embodiment of this application.

[0028] Figure 5 This is a schematic flowchart of a battery charging control method disclosed in an embodiment of this application;

[0029] Figure 6 This is a schematic flowchart of another battery charging control method disclosed in an embodiment of this application;

[0030] Figure 7 This is a schematic flowchart of another battery charging control method disclosed in an embodiment of this application;

[0031] Figure 8 This is a schematic diagram of the structure of a battery management module disclosed in one embodiment of this application; Detailed Implementation

[0032] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0033] In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable tolerance range. "Parallel" is not parallel in the strict sense, but within the allowable tolerance range.

[0034] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0035] Figure 1 A schematic diagram of a charging system applicable to an embodiment of this application is shown.

[0036] like Figure 1 As shown, the charging system 10 may include a charging power supply 100 and a vehicle electrical system 200. Optionally, the vehicle may be an electric vehicle, including pure electric vehicles and plug-in hybrid electric vehicles.

[0037] Optionally, the vehicle electrical system 200 may include at least one battery pack, which can be collectively referred to as a power battery, i.e., battery 210. In terms of battery type, the power battery can be any type of battery, including but not limited to: lithium-ion batteries, lithium metal batteries, lithium-sulfur batteries, lead-acid batteries, nickel-metal hydride batteries, or lithium-air batteries, etc. In terms of battery size, the power battery in this embodiment can be a cell, a battery module, or a battery pack, wherein a battery module or battery pack can be formed by multiple batteries connected in series and parallel. In this embodiment, the specific type and size of the power battery are not specifically limited.

[0038] In addition, to intelligently manage and maintain the power battery, prevent overcharging and over-discharging, and extend battery life, the vehicle electrical system 200 generally includes a battery management module 220 for controlling the vehicle electrical system and monitoring the status of the battery 210. The battery management module can be a battery management system (BMS) or a domain control unit (DCU). Optionally, the battery management module 220 can be integrated with the power battery in the same device or apparatus, or it can be a separate device / apparatus located outside the power battery.

[0039] Specifically, the charging power supply 100 is a device for replenishing electrical energy to the battery 210 in the vehicle electrical system 200. In this embodiment, the charging power supply 100 can be a fast-charging station, a charging station supporting vehicle-to-grid (V2G) mode, etc.

[0040] Optionally, the charging power supply 100 can be connected to the battery 210 via a wire and to the battery management module 220 via a communication line. The communication line is used to enable information exchange between the charging power supply 100 and the battery management module 220.

[0041] As an example, the communication line includes, but is not limited to, a Controller Area Network (CAN) communication bus or a daisy chain communication bus.

[0042] Optionally, in addition to communicating with the battery management module 220 via a communication line, the charging power supply 100 can also communicate with the battery management module 220 via a wireless network. This embodiment does not specifically limit the communication type between the charging power supply 100 and the battery management module 220.

[0043] Most new energy vehicles on the market use rechargeable batteries, the most common being lithium batteries, such as lithium-ion batteries or lithium-ion polymer batteries. The battery temperature and the uniformity of the temperature field have a significant impact on the performance and lifespan of the power battery. If the power battery operates at excessively low temperatures or is charged in a low-temperature environment, lithium plating will occur, leading to a deterioration in battery performance and severely affecting its capacity and lifespan. Therefore, when charging batteries in low-temperature environments, a heat treatment process is necessary first.

[0044] Currently, when a battery is in a low-temperature environment, such as when it is at a low SOC (State of Charge), it cannot discharge externally, and the battery heating module cannot function. In this case, only slow charging, via the onboard charger, can power the battery heating module to heat the battery. Once the battery temperature rises to a certain level, normal charging can begin. However, this method has limitations. Some vehicles lack a slow charging port, making it impossible to power the battery heating module via the onboard charger. For example, if a commercial vehicle only has a fast charging port, the vehicle will be unable to charge and function properly when the battery is at a low temperature and low SOC.

[0045] For fast charging stations, the conventional heating charging method requires changing the communication protocol to enable the charging station to recognize vehicles in low-temperature environments, thus providing auxiliary heating functionality. This method necessitates developing entirely new fast charging stations and adding or modifying the communication protocol during charging, making it incompatible with standard international protocols. Consequently, existing fast charging stations on the market cannot be widely adopted.

[0046] Therefore, to solve the above problems and enable charging piles to safely and efficiently charge low-SOC power batteries in low-temperature environments, this application provides a battery charging control method and a vehicle electrical system.

[0047] Figure 2 This diagram illustrates the connection between a vehicle electrical system 200 and a charging power supply 100 according to an embodiment of this application. The vehicle electrical system 200 includes a battery 210, a battery heating module 230, and a current control unit 240. One end of the current control unit 240 is connected to the battery 210, and the other end is connected to the charging power supply 100. The battery heating module 230 is connected in parallel with the battery 210 and the current control unit 240. One end of the battery heating module 230 is connected to the battery 210 and the charging power supply 100, and the other end is connected to the current control unit 240 and the charging power supply 100.

[0048] Optionally, such as Figure 3 As shown, the battery heating module 230 includes a third relay K3 and a heater R1, with the third relay K3 connected in series with the heater R1. The third relay K3 controls the connection or disconnection of the battery heating module 230 from the circuit, and the heater R1 heats the battery 210; it can be a PTC heater or a heating film. In this embodiment, the specific type and size of the heater in the battery heating module 230 are not specifically limited.

[0049] Optionally, such as Figure 4 The battery heating module 230 may further include a fourth relay K4. The third relay K3, the fourth relay K4 and the heater R1 are connected in series, and the third relay K3 and the fourth relay K4 are respectively disposed at both ends of the heater R1. The third relay K3 and the fourth relay K4 work together to control the battery heating module 230 to enter or exit the circuit, thereby enhancing the safety and reliability of the circuit system.

[0050] The current control unit 240 includes a semiconductor device. Optionally, such as Figure 3 As shown, the current control unit 240 includes a first relay K1 and a semiconductor device D1. One end of the first relay K1 is connected to the battery 210, and the other end of the first relay K1 is connected to the charging power supply 100; the semiconductor device D1 is connected in parallel with the first relay K1.

[0051] Optionally, such as Figure 4 As shown, the current control unit 240 includes a first relay K1 and a semiconductor device D1, and may also include a second relay K2. One end of the first relay K1 is connected to the battery 210, and the other end of the first relay K1 is connected to the charging power supply 100; the semiconductor device D1 is connected in parallel with the first relay K1; the second relay K2 is connected in the branch where the semiconductor device D1 is located.

[0052] Optionally, the semiconductor device D1 in the current control unit 240 can be a diode, a silicon controlled rectifier (SCR), a bidirectional IGBT, or other semiconductor devices. That is, by utilizing the unidirectional conductivity of semiconductors, current can be blocked by connecting the semiconductor device D1 in reverse in the circuit. Furthermore, by adjusting the connection direction of the semiconductor device D1 in the circuit, the current control unit 240 can be positioned on the positive or negative bus of the battery 210. This embodiment of the application uses the current control unit 240 positioned on the negative bus of the battery 210 as an example.

[0053] Optionally, the semiconductor device D1 in the current control unit 240 may be a bidirectional semiconductor device.

[0054] Figure 5 A charging control method 500 according to an embodiment of this application is shown, used for heating and charging a battery 210. The method 500 may specifically include some or all of the following steps.

[0055] Step 510: When the battery temperature is lower than the first preset temperature, the current control unit is in the first state.

[0056] The first state refers to the state where the semiconductor device is connected to the circuit in reverse. Specifically, the first preset temperature is the allowable charging temperature of the battery 210. When the temperature of the battery 210 is lower than the first preset temperature, the battery 210 is in a low-temperature state and needs to be heated before charging. At this time, the first relay K1 is disconnected to connect the semiconductor device D1 to the circuit in reverse, thereby controlling the current control unit 240 to block the current from passing through. The charging power supply 100 stops charging the battery 210, and at the same time, the charging power supply 100 and the battery heating module 230 form a circuit, thereby enabling the charging power supply 100 to supply power to the battery heating module 230 to heat the battery 210.

[0057] Optionally, such as Figure 4 As shown, the current control unit 240 also includes a second relay K2. When the temperature of the battery 210 is lower than the first preset temperature, the first relay K1 is disconnected and the second relay K2 is turned on, so that the semiconductor device D1 is connected to the circuit in reverse, thereby controlling the current control unit 240 to block the current from passing through.

[0058] Optionally, when the semiconductor device D1 in the current control unit 240 is a bidirectional semiconductor device, the direction of the bidirectional semiconductor device D1 in the circuit can be directly controlled to remain in the opposite direction to the current, thereby blocking the current from passing through.

[0059] When the current control unit 240 is in the first state, the battery heating module 230 is connected to the circuit, forming a loop with the charging power supply 100. Specifically, the third relay K3 and the fourth relay K4 are turned on, so that the charging power supply 100 supplies power to the battery heating module 230 to heat the battery 210.

[0060] Step 520: Send the first charging request.

[0061] The first charging request includes a first charging current, which is the current required to heat the battery to a first preset temperature and can be set according to the power of the battery heating module and other electrical appliances. Specifically, at this time, the charging power supply 100 is requested to send the first charging current to heat the battery 210 to the first preset temperature so that the battery 210 can be charged normally afterwards.

[0062] At this time, the first charging current output by the charging power supply 100 flows into the vehicle electrical system 200. Because the semiconductor device is connected to the circuit in reverse, the current control unit 240 is in its first state, meaning the current control unit 240 can block current flow. Therefore, the first charging current can flow into the battery heating module 230 to heat the battery 210, but will not flow into the battery 210 itself, thus preventing battery damage. Furthermore, because the battery 210 and the charging power supply 100 circuit remain connected, the vehicle electrical system 200 can successfully establish a connection with the charging power supply 100 and request charging current without requiring additional or modified communication protocols.

[0063] Step 530: When the battery temperature reaches the first preset temperature, the current control unit is in the second state.

[0064] The second state refers to either the state of the semiconductor device being connected to the circuit or the state of the semiconductor device being connected to the circuit. Specifically, when the temperature of the battery 210 reaches the first preset temperature, the battery 210 can be charged normally. At this time, the first relay K1 is turned on to short-circuit the semiconductor device connection circuit, that is, the semiconductor device D1 is short-circuited, thereby controlling the current control unit 240 to allow current to flow.

[0065] Optionally, such as Figure 4 As shown, the current control unit 240 also includes a second relay K2. When the temperature of the battery 210 reaches the first preset temperature, the first relay is turned on and the second relay K2 is turned off, so that the semiconductor device D1 is connected out of the circuit, that is, the semiconductor device D1 is bypassed, thereby controlling the current control unit 240 to allow current to pass through.

[0066] Optionally, when the semiconductor device D1 in the current control unit 240 is a bidirectional semiconductor device, the direction of the bidirectional semiconductor device D1 in the circuit can be directly controlled to remain in the positive direction relative to the current, thereby allowing the current to pass through.

[0067] At this time, the battery heating module 230 is connected to the circuit. Specifically, disconnecting the third relay K3 in the battery heating module 230, or simultaneously disconnecting the third relay K3 and the fourth relay K4, bypasses the current heating module 230, allowing the charging power supply 100 to perform normal charging to the battery 210.

[0068] Step 540: Send a second charging request.

[0069] The second charging request includes a second charging current. Specifically, based on the charging needs of the battery 210, the charging power supply 100 is requested to send a second charging current to charge the battery 210.

[0070] At this time, the battery heating module 230 is bypassed, and the current control unit 240 is in the second state, that is, the current control unit 240 allows current to pass through, and the second charging current output by the charging power supply 100 can flow to the battery 210 for normal charging.

[0071] In this embodiment, a current control unit is installed in the vehicle's electrical system. When the battery temperature is below a first preset temperature and the battery needs heating, the semiconductor device is reverse-connected to the circuit, and the current control unit is in a first state, meaning the current control unit blocks current flow. This ensures that the battery remains connected to the charging power supply and successfully requests charging current without adding or modifying the communication protocol, while effectively preventing the first charging current from flowing into the battery and causing damage. When the battery temperature reaches the first preset temperature allowing charging, the semiconductor device is either connected to the circuit in the first preset direction or in the forward direction, and the current control unit is in a second state, meaning the current control unit allows current flow. This allows the vehicle's electrical system to directly enter normal fast charging mode when the battery temperature reaches the allowable charging temperature, without affecting the battery's charging efficiency. By setting up the current control unit and controlling its operating state, safe and efficient low-temperature heating and charging of low-temperature, low-SOC batteries can be achieved.

[0072] Furthermore, the charging control method of the above embodiments can be extended to, for example... Figure 6 The charging control method 600 shown may specifically include some or all of the following steps.

[0073] Step 610: When the battery temperature is lower than the first preset temperature, the current control unit is in the first state.

[0074] The first state is the state in which the semiconductor device is connected to the circuit in reverse. The specific execution method is similar to that in method 500, and will not be described again here.

[0075] Step 620: Send the first charging request.

[0076] The first charging request includes a first charging current, which is the current required to heat the battery to a first preset temperature and can be set according to the power of the battery heating module and other electrical appliances. Specifically, at this time, the charging power supply 100 is requested to send the first charging current to heat the battery 210 to the first preset temperature so that the battery 210 can be charged normally afterwards.

[0077] Step 630: When the battery temperature reaches the first preset temperature, send the first charging request, including: the first charging current is 0.

[0078] Specifically, when the battery temperature reaches the first preset temperature, the first charging current output by the charging power supply 100 is reduced to 0, and then the operating state of the current control unit 240 is switched to the second state. That is, when switching the operating state of the current control unit 240, the charging current used for heating is reduced to 0. This prevents current from flowing into the power battery and causing damage during the switching of the current control unit's operating state, further ensuring the safety of low-temperature charging of the battery.

[0079] Step 640: The current control unit is in the second state.

[0080] The second state refers to either the state where the semiconductor device is connected out of the circuit or the state where the semiconductor device is connected to the circuit in the forward direction. The specific execution method is the same as that described in method 500, and will not be repeated here.

[0081] Step 650: Send a second charging request.

[0082] The second charging request includes a second charging current. Specifically, based on the charging needs of the battery 210, the charging power supply 100 is requested to send a second charging current to charge the battery 210.

[0083] In this embodiment, when the battery temperature has been heated to a first preset temperature, a first charging current of 0 is requested, and then the current control unit is controlled to enter a second state, that is, when switching the operating state of the current control unit, the charging current is reduced to 0. This prevents current from flowing into the power battery during the switching of the current control unit's operating state and causing damage to the power battery, further ensuring the safety of low-temperature charging of the battery.

[0084] Figure 7This is a schematic flowchart illustrating one possible implementation of the charging control method described above. By controlling the operating state of the current control unit, safe and efficient low-temperature charging of low-temperature, low-SOC batteries is achieved. Figure 4 Taking the vehicle electrical system shown as an example, method 700 may specifically include:

[0085] Step 701: Confirm the connection between the charging power source and the vehicle, and begin charging.

[0086] Step 702: Check whether the battery temperature meets the first preset temperature.

[0087] The first preset temperature is the allowable charging temperature of battery 210. If the temperature of battery 210 meets the first preset temperature, there is no need to heat battery 210, and the process proceeds to step 708; if the temperature of battery 210 does not meet the first preset temperature, the process proceeds to step 703, and battery 210 is heated.

[0088] Step 703: Disconnect K1 and connect K2 to put the current control unit in the first state.

[0089] The first state is when the semiconductor device is connected to the circuit in reverse. In this state, the first relay K1 is disconnected and the second relay K2 is turned on.

[0090] Step 704: Turn on K3 and K4 to connect the battery heating module to the circuit.

[0091] Step 705: Send a first charging request, including: a first charging current.

[0092] The first charging current is the current required to heat the battery 210 to a first preset temperature, and can be set according to the power of the battery heating module 230. At this time, the charging power supply 100 is requested to send the first charging current to heat the battery 210 to the first preset temperature so that the battery 210 can be charged normally afterwards.

[0093] Step 706: Check whether the battery temperature meets the first preset temperature.

[0094] After heating the battery 210, the heating effect is tested. If the temperature of the battery 210 meets the first preset temperature, heating is stopped and the process proceeds to step 707; if the temperature does not meet the first preset temperature, heating of the battery 210 continues and the process proceeds to step 703.

[0095] Step 707: Send a first charging request, including: the first charging current is 0.

[0096] When the battery temperature reaches the first preset temperature, the first charging current output by the charging power supply 100 is requested to be reduced to 0, and then the working state of the current control unit 240 is switched to the second state, that is, when switching the working state of the current control unit 240, the charging current is reduced to 0.

[0097] Step 708: Close K1 and open K2 to put the current control unit in the second state.

[0098] The second state is the state of the semiconductor device's output circuit. In this state, the first relay K1 is turned on and the second relay K2 is turned off.

[0099] Step 709: Disconnect K3 and K4 to bypass the battery heating module.

[0100] Step 710: Send a second charging request, including: a second charging current.

[0101] At this time, the battery heating module is bypassed, and the current control unit 240 is in the second state, that is, current is allowed to pass through, and the charging power supply 100 is requested to output a second charging current to charge the battery 210 normally.

[0102] Step 711: Charging complete.

[0103] As can be seen from the above possible methods, by controlling the working state of the current control unit, the battery can maintain a connection with the charging power supply and successfully request the charging power supply to output charging current without adding or modifying the communication protocol. It can also prevent the current output by the charging power supply from flowing into the battery during low-temperature charging, which would cause battery damage. Thus, the charging power supply can safely and efficiently charge low-temperature, low-SOC batteries.

[0104] This application also provides a vehicle electrical system, including a current control unit, a control module, and a communication module. The current control unit includes a semiconductor device, one end of which is connected to a battery, and the other end is connected to a charging power supply. The control module controls the current control unit to be in a first state when the battery temperature is lower than a first preset temperature, wherein the first state is a state where the semiconductor device is connected to the circuit in reverse. The communication module sends a first charging request, the first charging request including a first charging current, which is the current required to heat the battery to the first preset temperature. The control module is further configured to control the current control unit to be in a second state when the battery temperature reaches the first preset temperature, wherein the second state is a state where the semiconductor device is connected to the circuit out; the communication module is further configured to send a second charging request, the second charging request including a second charging current, with the battery being charged using the second charging current.

[0105] Specifically, the control module is connected to the battery heating module 230 and the current control unit 240 in the vehicle electrical system 200, and is used to control the on and off states of K1, K2, K3, and K4, thereby controlling whether the battery heating module 230 is connected to the circuit or bypassed, and whether the current control unit 240 is in a first state or a second state. The communication module is used to interact with the charging power supply 100, and its communication methods include, but are not limited to, control area network (CAN) communication or daisy chain communication.

[0106] like Figure 8 As shown, this application embodiment also provides a battery management module 220, including a processor 221 and a memory 222. The memory 222 is used to store computer programs, and the processor 221 is used to call the computer programs to execute the charging control methods in the aforementioned embodiments of this application.

[0107] This application also provides a readable storage medium for storing a computer program for executing the charging control methods described in the foregoing embodiments of this application.

[0108] This application also provides a vehicle including the vehicle electrical system described in the foregoing embodiments of this application.

[0109] It should be understood that the specific examples in this document are only intended to help those skilled in the art better understand the embodiments of this application, and are not intended to limit the scope of the embodiments of this application.

[0110] It should also be understood that, in the various embodiments of this application, the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The various implementation methods described in this specification can be implemented individually or in combination, and the embodiments of this application do not limit this.

[0111] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery charging control method, applied to a vehicle electrical system, characterized in that, The vehicle electrical system includes a battery, a battery heating module, and a current control unit. The current control unit includes semiconductor devices. One end of the current control unit is connected to the battery, and the other end is connected to a charging power source. The battery heating module is connected to the charging power source via a switch. The method includes: When the temperature of the battery is lower than a first preset temperature, the current control unit is controlled to be in a first state, wherein the first state includes the state of the semiconductor device being connected to the reverse circuit to block the current from the charging power supply to the battery, and the switch being in a closed state to connect the battery heating module to the charging power supply. Send a first charging request to the charging power source, the first charging request including a first charging current, the first charging current being the current required by the battery heating module to heat the battery to the first preset temperature; When the battery temperature reaches the first preset temperature, a charging request is sent to the charging power supply to reduce the charging current to 0 during the process of the current control unit switching from the first state to the second state. The current control unit is controlled to be in a second state, wherein the second state includes the state of the semiconductor device being connected to the circuit or the state of the semiconductor being connected to the circuit from the charging power source to the battery. The switch is controlled to be in the off state to disconnect the battery heating module from the charging power supply; A second charging request is sent to the charging power source, the second charging request including a second charging current, and the battery is charged with the second charging current.

2. The control method according to claim 1, characterized in that, The current control unit includes a semiconductor device and a first relay. The step of controlling the current control unit to be in a first state when the battery temperature is lower than a first preset temperature includes: When the temperature of the battery is lower than the first preset temperature, the control disconnects the first relay, wherein one end of the first relay is connected to the battery, the other end of the first relay is connected to the charging power supply, and the semiconductor device is connected in parallel with the first relay.

3. The control method according to claim 1, characterized in that, The current control unit includes a semiconductor device and a first relay. The step of controlling the current control unit to be in a second state when the battery temperature reaches the first preset temperature includes: When the battery temperature reaches the first preset temperature, the first relay is activated. One end of the first relay is connected to the battery, and the other end of the first relay is connected to the charging power supply. The semiconductor device is connected in parallel with the first relay.

4. The control method according to claim 1, characterized in that, The current control unit includes a bidirectional semiconductor device. The step of controlling the current control unit to be in a second state when the battery temperature reaches the first preset temperature includes: When the battery temperature reaches the first preset temperature, the bidirectional semiconductor device is controlled to switch, so that the bidirectional semiconductor device is connected to the circuit in the forward direction.

5. A vehicle electrical system, characterized in that, The system includes: The battery heating module is connected to the charging power supply via a switch; A current control unit, comprising a semiconductor device, wherein one end of the current control unit is connected to a battery and the other end is connected to a charging power supply; The control module is used to control the current control unit to be in a first state when the temperature of the battery is lower than a first preset temperature. The first state includes the state of the semiconductor device reverse access circuit to block the current from the charging power supply to the battery, and the switch is in a closed state to connect the battery heating module to the charging power supply. The communication module is used to send a first charging request to the charging power supply. The first charging request includes a first charging current, which is the current required by the battery heating module to heat the battery to the first preset temperature. When the battery temperature reaches the first preset temperature, the communication module sends a charging request to the charging power supply to reduce the charging current to 0 during the process of the current control unit switching from the first state to the second state. The control module is also configured to, when the battery temperature reaches the first preset temperature, control the current control unit to be in a second state, wherein the second state includes the state of the semiconductor device being connected to the circuit or the state of the semiconductor being connected to the circuit from the charging power supply to the battery; and to control the switch to be in an open state to disconnect the battery heating module from the charging power supply. The communication module is also used to send a second charging request to the charging power supply, the second charging request including a second charging current, and the battery is charged with the second charging current.

6. The system according to claim 5, characterized in that, The current control unit further includes: a first relay, one end of which is connected to the battery, and the other end of which is connected to a charging power supply; the semiconductor device is connected in parallel with the first relay, wherein... When the temperature of the battery is lower than a first preset temperature, the current control unit is in a first state, and in the first state, the first relay is disconnected; When the battery temperature reaches the first preset temperature, the current control unit is in the second state, and in the second state, the first relay is turned on.

7. The system according to claim 6, characterized in that, The current control unit further includes a second relay, which is connected to the branch containing the semiconductor device, wherein... When the temperature of the battery is lower than the first preset temperature, the current control unit is in a first state, in which the first relay is disconnected and the second relay is turned on; When the battery temperature reaches the first preset temperature, the current control unit is in a second state. In the second state, the first relay is turned on and the second relay is turned off.

8. A battery management system, characterized in that, It includes a processor and a memory, the memory being used to store a computer program, and the processor being used to invoke the computer program to execute the method of any one of claims 1 to 4.

9. A readable storage medium, characterized in that, Used to store a computer program for performing the method described in any one of claims 1 to 4.

10. A vehicle, characterized in that, The vehicle electrical system includes any one of claims 5 to 7.

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