Charging control method, system and device and BMS

Abstract

The embodiment of the invention provides a charging control method, system and device and a BMS. The method comprises the following steps: generating a charging request voltage according to a battery pack total voltage of a battery pack and a set first set voltage; generating a request charging current according to the resistance rated power of the heating resistor and the request charging voltage; and a charging request signal is sent to the charging pile, and the charging request signal comprises the charging request voltage and the charging request current, so that the charging pile provides resistance current for the heating resistor and provides battery pack current for the battery pack according to the charging request voltage and the charging request current. According to the technical scheme, the problem that the battery pack is damaged due to the fact that the current of the battery pack is too large in the heating process is solved, the process that the high-voltage relay is disconnected and closed in the heating process is avoided, the charging process is simplified, the fault rate of the charging control circuit is reduced, and the service life of the high-voltage relay is prolonged.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of battery charging, and in particular, to a charging control method, system, device, and BMS. Background Art

[0002] At present, in a cold ambient temperature, the temperature of the power battery pack of a new energy vehicle drops to the lowest safe temperature at which the battery cells allow current to be charged. At this time, the power battery cannot be directly charged. The lowest safe temperature at which ternary lithium battery cells allow current to be charged is -5°C, and the lowest safe temperature at which lithium iron phosphate battery cells allow current to be charged is 0°C. When the temperature of the power battery pack is lower than the lowest safe temperature at which the battery cells allow current to be charged, if a large current is charged into the power battery pack at this time, lithium plating will occur inside the battery cells, resulting in serious damage to the power battery pack. Therefore, during low-temperature charging, it is necessary to first disconnect the high-voltage circuit of the battery and heat the power battery pack to make the temperature of the power battery pack higher than the lowest safe temperature at which the battery cells allow current to be charged. At this time, the high-voltage circuit is closed again to allow current to be charged into the power battery pack. Therefore, during the heating process, the high-voltage relay needs to be disconnected and then closed, increasing the complexity of the charging process, increasing the failure rate, and shortening the service life of the high-voltage relay. Summary of the Invention

[0003] In view of this, embodiments of the present invention provide a charging control method, system, device, and BMS, which are used to solve the problem that the high-voltage relay needs to be disconnected and then closed during the heating process, simplify the charging process, reduce the failure rate of the charging control circuit, and improve the service life of the high-voltage relay.

[0004] In a first aspect, a charging control method is provided, and the method includes:

[0005] Generating a requested charging voltage according to the total voltage of the battery pack and a set first set voltage;

[0006] Generating a requested charging current according to the rated power of the heating resistor and the requested charging voltage;

[0007] Sending a requested charging signal to the charging pile, where the requested charging signal includes the requested charging voltage and the requested charging current, so that the charging pile provides a resistor current to the heating resistor and a battery pack current to the battery pack according to the requested charging voltage and the requested charging current.

[0008] In a possible implementation method, the method further includes:

[0009] Obtaining the battery pack current of the battery pack detected by a current sensor;

[0010] Judging whether the battery pack current is greater than or equal to a set threshold;

[0011] If the current of the battery pack is greater than or equal to the set threshold value, then switch the current state to the fault state;

[0012] If the current of the battery pack is less than the set threshold value, then switch the current state according to the first cell temperature of the battery pack detected by the temperature sensor.

[0013] In a possible implementation method, the switching of the current state according to the first cell temperature of the battery pack detected by the temperature sensor includes:

[0014] Obtain multiple first cell temperatures of the battery pack from multiple of the temperature sensors;

[0015] Select the minimum first cell temperature and the maximum first cell temperature from the multiple first cell temperatures;

[0016] Judge whether the minimum first cell temperature is within the first threshold range, the second threshold range or the third threshold range, and judge whether the maximum first cell temperature is greater than or equal to a first set temperature, the first threshold range includes a numerical range less than a second set temperature, the second threshold range includes a numerical range greater than or equal to the second set temperature and less than a third set temperature, and the third threshold range includes a numerical range greater than or equal to the third set temperature;

[0017] If the minimum first cell temperature is within the first threshold range and the maximum first cell temperature is less than the first set temperature, then continue to execute the step of judging whether the current of the battery pack is greater than or equal to the set threshold value;

[0018] If the minimum first cell temperature is within the second threshold range and the maximum first cell temperature is less than the first set temperature, then switch the current state to the state of charging while heating;

[0019] If the minimum first cell temperature is within the third threshold range, then switch the current state to the charging state;

[0020] If the maximum first cell temperature is greater than or equal to the first set temperature, then switch the current state to the charging state.

[0021] In a possible implementation method, before generating a requested charging voltage according to the total voltage of the battery pack and a set first set voltage, it further includes:

[0022] Send a closing signal to the heating relay for the heating relay to close according to the closing signal;

[0023] Detect whether the heating relay is closed;

[0024] If the heating relay is closed, continue to execute the step of generating a requested charging voltage according to the total voltage of the battery pack and a set first set voltage;

[0025] If the heating relay is not closed, switch the current state to a fault state.

[0026] In a possible implementation method, before sending a closing signal to the heating relay for the heating relay to close according to the closing signal, it further includes:

[0027] Obtain a plurality of second cell temperatures of the battery pack from a plurality of the temperature sensors;

[0028] Screen out the minimum second cell temperature and the maximum second cell temperature from the plurality of second cell temperatures;

[0029] If the minimum second cell temperature is within a first threshold range and the maximum second cell temperature is less than the first set temperature, switch the current state to a heating state, where the first threshold range includes a numerical range less than a second set temperature.

[0030] In a possible implementation method, the method further includes:

[0031] If the minimum second cell temperature is within a second threshold range and the maximum second cell temperature is less than the first set temperature, switch the current state to a state of heating while charging, where the second threshold range includes a numerical range greater than or equal to the second set temperature and less than a third set temperature;

[0032] If the minimum second cell temperature is within the third threshold range, switch the current state to a charging state, where the third threshold range includes a numerical range greater than or equal to the third set temperature;

[0033] If the maximum second cell temperature is greater than or equal to the first set temperature, switch the current state to a charging state.

[0034] In a possible implementation method, before obtaining the plurality of second cell temperatures of the battery pack from the plurality of temperature sensors, it further includes:

[0035] Receive a feedback signal sent by a vehicle control unit VCU, where the feedback signal includes an allow signal or a prohibit signal;

[0036] Judge whether the feedback signal is the allow signal;

[0037] If the feedback signal is the prohibit signal, switch the current state to a fault state;

[0038] If the feedback signal is the permission signal, continue to execute the step of obtaining multiple second cell temperatures of the battery pack from multiple of the temperature sensors.

[0039] In a method that may be implemented, before receiving the feedback signal sent by the vehicle control unit VCU, it further includes:

[0040] Determine whether an access signal sent by the resistance sensor is received;

[0041] If the access signal sent by the resistance sensor is not received, switch the current mode to the discharge mode;

[0042] If the access signal sent by the resistance sensor is received, switch the current mode to the charging mode and send a notification signal to the VCU for the VCU to detect whether the current vehicle state allows charging in response to the notification signal and send the feedback signal.

[0043] In a second aspect, a charging control system is provided, including:

[0044] The BMS is configured to generate a requested charging voltage according to the total voltage of the battery pack and a set first set voltage; generate a requested charging current according to the rated power of the heating resistor and the requested charging voltage; send a requested charging signal to the charging pile, where the requested charging signal includes the requested charging voltage and the requested charging current; so that the charging pile provides a resistance current to the heating resistor and a battery pack current to the battery pack according to the requested charging voltage and the requested charging current.

[0045] In a third aspect, a vehicle is provided, including: the charging control system in the second aspect above.

[0046] In a fourth aspect, a charging control device is provided, including:

[0047] A first generation module, configured to generate a requested charging voltage according to the total voltage of the battery pack and a set first set voltage;

[0048] A second generation module, configured to generate a requested charging current according to the rated power of the heating resistor and the requested charging voltage;

[0049] A transceiver module, configured to send a requested charging signal to the charging pile, where the requested charging signal includes the requested charging voltage and the requested charging current, so that the charging pile provides a resistance current to the heating resistor and a battery pack current to the battery pack according to the requested charging voltage and the requested charging current.

[0050] A fifth aspect provides a BMS, including: one or more processors; a memory; and one or more computer programs, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions that, when executed by the BMS, cause the device to execute the charging control method in the above-mentioned first aspect or any possible implementation manner of the first aspect.

[0051] In a sixth aspect, an embodiment of the present invention provides a computer-readable storage medium, where the computer-readable storage medium includes a stored program, and when the program runs, it controls the BMS where the computer-readable storage medium is located to execute the charging control method in the above-mentioned first aspect or any possible implementation manner of the first aspect.

[0052] In the technical solution of the embodiment of the present invention, the BMS generates a requested charging voltage according to the total voltage of the battery pack and a set first set voltage, and generates a requested charging current according to the rated power of the heating resistor and the requested charging voltage, so that the charging pile provides a resistance current to the heating resistor and a battery pack current to the battery pack according to the requested charging voltage and the requested charging current, solving the problem of damage to the battery pack caused by excessive battery pack current during the heating process, thereby avoiding the process of the high-voltage relay disconnecting and then closing during the heating process, simplifying the charging process, reducing the failure rate of the charging control circuit, and increasing the service life of the high-voltage relay. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0054] Figure 1 It is a schematic structural diagram of a charging control system provided by an embodiment of the present invention;

[0055] Figure 2 It is a schematic structural diagram of a charging control circuit provided by an embodiment of the present invention;

[0056] Figure 3 It is a flowchart of a charging control method provided by an embodiment of the present invention;

[0057] Figure 4 It is a flowchart of another charging control method provided by an embodiment of the present invention;

[0058] Figure 5 It is a flowchart of a state switching method provided by an embodiment of the present invention;

[0059] Figure 6 Flow chart of another charging control method provided by an embodiment of the present invention;

[0060] Figure 7 Flow chart of another state switching method provided by an embodiment of the present invention;

[0061] Figure 8 Flow chart of another charging control method provided by an embodiment of the present invention;

[0062] Figure 9 Flow chart of another charging control method provided by an embodiment of the present invention;

[0063] Figure 10 Schematic structural diagram of a charging control device provided by an embodiment of the present invention;

[0064] Figure 11 Schematic structural diagram of a second switching module provided by an embodiment of the present invention;

[0065] Figure 12 Schematic diagram of a BMS provided by an embodiment of the present invention. Detailed implementation manners

[0066] For a better understanding of the technical solutions of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0067] It should be clear that the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0068] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "the" and "said" used in the embodiments of the present invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0069] It should be understood that the term " / and" used herein is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, a and / or b may represent: a exists alone, a and b exist simultaneously, and b exists alone. In addition, the character " / " in this text generally represents an "or" relationship between the associated objects before and after.

[0070] Figure 1 Schematic structural diagram of a charging control system provided by an embodiment of the present invention, as Figure 1As shown in the figure, the system includes: a Battery Management System (BMS) 10.

[0071] The BMS 10 is configured to generate a requested charging voltage based on the total voltage of the battery pack and a set first set voltage; generate a requested charging current based on the rated power of the heating resistor and the requested charging voltage; and send a requested charging signal to the charging pile 20, where the requested charging signal includes the requested charging voltage and the requested charging current, so that the charging pile 20 provides a resistance current to the heating resistor and a battery pack current to the battery pack according to the requested charging voltage and the requested charging current.

[0072] Next, through Figure 2 the charging control circuit shown in the figure, structures such as the heating resistor and the battery pack will be described. Figure 2 It is a schematic structural diagram of a charging control circuit provided by an embodiment of the present invention. As Figure 2 shown in the figure, the charging control circuit includes: a battery pack BP, a heating resistor R1, a heating relay SW1, a high-voltage circuit negative relay SW2, a high-voltage circuit positive relay SW3, a charging positive terminal a, a charging negative terminal b, a discharging positive terminal c, and a discharging negative terminal d. The positive electrode of the battery pack BP is electrically connected to the charging positive terminal a, the negative electrode of the battery pack BP is electrically connected to the first end of the high-voltage circuit negative relay SW2, the second end of the high-voltage circuit negative relay SW2 is electrically connected to the discharging negative terminal d, the first end of the heating relay SW1 is electrically connected to the charging positive terminal a, the second end of the heating relay SW1 is electrically connected to the first end of the heating resistor R1, the second end of the heating resistor R1 is electrically connected to the discharging negative terminal d, the first end of the high-voltage circuit positive relay SW3 is electrically connected to the charging positive terminal a, the second end of the high-voltage circuit positive relay SW3 is electrically connected to the discharging positive terminal c, and the charging negative terminal c is electrically connected to the discharging negative terminal d.

[0073] As Figure 1 and Figure 2 shown in the figure, the charging pile 20 is electrically connected to the charging positive terminal a and the charging negative terminal b.

[0074] In an embodiment of the present invention, the system further includes: a current sensor 30 and a temperature sensor 40. The current sensor 30 is connected to the BMS 10, and the temperature sensor 40 is connected to the BMS 10. The current sensor 30 is configured to detect the battery pack current of the battery pack. The temperature sensor 40 is configured to detect the first cell temperature of the battery pack BP. The BMS 10 is further configured to obtain the battery pack current of the battery pack detected by the current sensor 30; determine whether the battery pack current is greater than or equal to a set threshold; if the battery pack current is greater than or equal to the set threshold, switch the current state to a fault state; if the battery pack current is less than the set threshold, switch the current state according to the first cell temperature of the battery pack detected by the temperature sensor 40.

[0075] In an embodiment of the present invention, BMS10 is specifically configured to obtain multiple first cell temperatures of the battery pack BP from multiple temperature sensors 40; screen out the minimum first cell temperature and the maximum first cell temperature from the multiple first cell temperatures; determine whether the minimum first cell temperature is within the first threshold range, the second threshold range, or the third threshold range, and determine whether the maximum first cell temperature is greater than or equal to the first set temperature. The first threshold range includes a numerical range less than the second set temperature, the second threshold range includes a numerical range greater than or equal to the second set temperature and less than the third set temperature, and the third threshold range includes a numerical range greater than or equal to the third set temperature; if the minimum first cell temperature is within the first threshold range and the maximum first cell temperature is less than the first set temperature, then continue to execute the step of determining whether the battery pack current is greater than or equal to the set threshold; if the minimum first cell temperature is within the second threshold range and the maximum first cell temperature is less than the first set temperature, then switch the current state to the charging while heating state; if the minimum first cell temperature is within the third threshold range, then switch the current state to the charging state; if the maximum first cell temperature is greater than or equal to the first set temperature, then switch the current state to the charging state.

[0076] In an embodiment of the present invention, the system further includes: a heating relay SW1, and the heating relay SW1 is connected to BMS10. BMS10 is further configured to send a closing signal to the heating relay SW1. The heating relay SW1 is configured to close according to the closing signal. BMS10 is further configured to detect whether the heating relay SW1 is closed. If the heating relay SW1 is closed, then continue to execute the step of generating a requested charging voltage according to the total battery pack voltage of the battery pack and the set first set voltage; if the heating relay SW1 is not closed, then switch the current state to the fault state.

[0077] In an embodiment of the present invention, as Figure 1 and Figure 2 shown, the heating relay SW1 closes according to the closing signal sent by BMS10, so that the heating resistor R1 can receive a resistor current for the heating resistor R1 to heat the battery pack BP.

[0078] In an embodiment of the present invention, the BMS 10 is further configured to obtain multiple second cell temperatures of the battery pack BP from multiple temperature sensors 40; screen out the minimum second cell temperature and the maximum second cell temperature from the multiple second cell temperatures; determine whether the minimum second cell temperature is within a first threshold range, a second threshold range, or a third threshold range, and determine whether the maximum second cell temperature is greater than or equal to a first set temperature, where the first threshold range includes a numerical range less than a second set temperature, the second threshold range includes a numerical range greater than or equal to the second set temperature and less than a third set temperature, and the third threshold range includes a numerical range greater than or equal to the third set temperature; if the minimum second cell temperature is within the first threshold range and the maximum second cell temperature is less than the first set temperature, then switch the current state to a heating state.

[0079] In an embodiment of the present invention, the BMS 10 is further configured to, if the minimum second cell temperature is within the second threshold range and the maximum second cell temperature is less than the first set temperature, then switch the current state to a state of charging while heating; if the minimum second cell temperature is within the third threshold range, then switch the current state to a charging state; if the maximum second cell temperature is greater than or equal to the first set temperature, then switch the current state to a charging state.

[0080] In an embodiment of the present invention, the system further includes: a vehicle control unit (VCU) 50, and the VCU 50 is connected to the BMS 10. The VCU 50 is configured to send a feedback signal to the BMS 10, and the feedback signal includes an allow signal or a prohibit signal. The temperature sensor 40 is further configured to detect the second cell temperature of the battery pack. The BMS 10 is further configured to determine whether the feedback signal is an allow signal. If the feedback signal is a prohibit signal, then switch the current state to a fault state; if the feedback signal is an allow signal, then continue to execute the step of obtaining multiple second cell temperatures of the battery pack BP from multiple temperature sensors 40.

[0081] In an embodiment of the present invention, the system further includes: a resistance sensor 60, and the resistance sensor 60 is connected to the BMS 10. The resistance sensor 60 is configured to send an access signal to the BMS 10. The BMS 10 is further configured to determine whether it has received the access signal sent by the resistance sensor 60. If it has not received the access signal sent by the resistance sensor 60, then switch the current mode to a discharge mode; if it has received the access signal sent by the resistance sensor 60, then switch the current mode to a charging mode and send a notification signal to the VCU 60; the VCU 60 is further configured to detect whether the current vehicle state allows charging in response to the notification signal and send the feedback signal.

[0082] In the technical solution of the embodiment of the present invention, the BMS generates a requested charging voltage based on the total voltage of the battery pack and a set first set voltage, and generates a requested charging current based on the rated power of the heating resistor and the requested charging voltage, so that the charging pile provides a resistance current to the heating resistor and a battery pack current to the battery pack according to the requested charging voltage and the requested charging current, solving the problem of damage to the battery pack caused by excessive battery pack current during the heating process, thereby avoiding the process of the high-voltage relay disconnecting and then closing during the heating process, simplifying the charging process, reducing the failure rate of the charging control circuit, and increasing the service life of the high-voltage relay.

[0083] An embodiment of the present invention provides a vehicle, which may include a charging control system. Among them, the charging control system may adopt Figure 1 the charging control system in the embodiment shown, and the specific description can be referred to Figure 1 the description in the embodiment shown, which will not be elaborated here.

[0084] Figure 3 is a flowchart of a charging control method provided by an embodiment of the present invention. As Figure 3 shown, the method includes:

[0085] Step 102: The BMS generates a requested charging voltage based on the total voltage of the battery pack and a set first set voltage.

[0086] Specifically, the BMS calculates the total voltage of the battery pack and the first set voltage according to the formula U1 = U0 + U2 to generate a requested charging voltage, where U1 is the requested charging voltage, U0 is the total voltage U0 of the battery pack BP, and U2 is the first set voltage.

[0087] Among them, as Figure 2 shown, the requested charging voltage U1 may be the potential difference between the positive charging terminal a and the negative charging terminal b.

[0088] Among them, the first set voltage U2 is much smaller than the total voltage U0 of the battery pack. For example, the first set voltage U2 may be 2V. In practical applications, the first set voltage U2 may also be set to other values, and the embodiment of the present invention does not limit this.

[0089] Step 104: The BMS generates a requested charging current based on the rated power of the heating resistor and the requested charging voltage.

[0090] Specifically, the BMS calculates the rated power of the heating resistor and the requested charging voltage through the formula I1 = W1 / U1 to generate a requested charging current, where I1 is the requested charging current, W1 is the rated power W1 of the heating resistor, and U1 is the requested charging voltage.

[0091] Step 106: The BMS sends a charging request signal to the charging pile. The charging request signal includes a requested charging voltage and a requested charging current.

[0092] Step 108: The charging pile provides a resistance current to the heating resistor and a battery pack current to the battery pack according to the requested charging voltage and the requested charging current.

[0093] As Figure 2 shown, the current flowing into the heating resistor R1 can be the resistance current, and the current flowing into the battery pack BP can be the battery pack current.

[0094] In the embodiment of the present invention, Figure 4 is a flowchart of another charging control method provided by the embodiment of the present invention. As Figure 4 shown, after step 108, it further includes:

[0095] Step 202: The BMS obtains the battery pack current of the battery pack detected by the current sensor.

[0096] Step 204: The BMS determines whether the battery pack current is greater than or equal to a set threshold. If so, step 206 is executed; if not, step 208 is executed.

[0097] In the embodiment of the present invention, for example, the set threshold can include 1A. In practical applications, the set threshold can be set to other values according to different types of battery packs. The embodiment of the present invention does not limit this.

[0098] Specifically, if the BMS determines that the battery pack current is greater than or equal to the set threshold, it indicates that the inflow current of the battery pack is too large at this time, which will cause lithium plating inside the battery cells in the battery pack and damage the battery pack. When the BMS determines that a charging overcurrent fault occurs in the battery pack, step 206 is executed; if the BMS determines that the battery pack current is less than the set threshold, it indicates that the inflow current of the battery pack is within the safe range at this time, and lithium plating will not occur inside the battery cells in the battery pack, thus not causing damage to the battery pack, and step 208 is executed.

[0099] Step 206: The BMS switches the current state to a fault state.

[0100] In the embodiment of the present invention, after the BMS switches the current state to a fault state, it sends a fault signal to the charging pile for the charging pile to stop providing a resistance current to the heating resistor and stop providing a battery pack current to the battery pack according to the fault signal.

[0101] Step 208: The BMS switches the current state according to the first cell temperature of the battery pack detected by the temperature sensor.

[0102] As an optional solution, Figure 5The flowchart of a state switching method provided by an embodiment of the present invention is as follows. Figure 5 As shown, step 208 may specifically include:

[0103] Step S11: The BMS obtains multiple first cell temperatures of the battery pack from multiple temperature sensors.

[0104] In an embodiment of the present invention, the battery pack includes multiple cells, each cell corresponds to a temperature sensor, and each temperature sensor can collect the cell temperature of the corresponding cell, so that multiple temperature sensors can collect multiple first cell temperatures.

[0105] Step S12: The BMS screens out the minimum first cell temperature t1 and the maximum first cell temperature t2 from the multiple first cell temperatures.

[0106] Step S13: The BMS determines whether the minimum first cell temperature t1 is within the first threshold range, the second threshold range, or the third threshold range, and determines whether the maximum first cell temperature t2 is greater than or equal to the first set temperature T2. The first threshold range includes a numerical range less than the second set temperature T2, the second threshold range includes a numerical range greater than or equal to the second set temperature T2 and less than the third set temperature T3, and the third threshold range includes a numerical range greater than or equal to the third set temperature T3. If the minimum first cell temperature t1 is within the first threshold range and the maximum first cell temperature t2 is less than the first set temperature T2, then step 204 is executed; if the minimum first cell temperature t1 is within the second threshold range and the maximum first cell temperature t2 is less than the first set temperature T2, then step S14 is executed; if the minimum first cell temperature t1 is within the third threshold range, then step S15 is executed; if the maximum first cell temperature t2 is greater than or equal to the first set temperature T2, then step S15 is executed.

[0107] In an embodiment of the present invention, the minimum first cell temperature t1 being within the first threshold range may include the minimum first cell temperature t1 being greater than or equal to the second set temperature T1; the minimum first cell temperature t1 being within the second threshold range may include the minimum first cell temperature t1 being greater than or equal to the second set temperature T2 and the minimum first cell temperature t1 being less than the third set temperature T3; the minimum first cell temperature t1 being within the third threshold range may include the minimum first cell temperature t1 being greater than or equal to the third set temperature T3.

[0108] The third set temperature T3 should be greater than the second set temperature T2, and the first set temperature T1 should be greater than the third set temperature T3. For example, the first set temperature T1 can include 40 degrees, the second set temperature T2 can include 0 degrees, and the third set temperature T3 can include 15 degrees. In practical applications, the first set temperature T1, the second set temperature T2, and the third set temperature T3 can be set to other values according to different types of battery cells. The embodiments of the present invention do not limit this.

[0109] Specifically, if the BMS determines that the minimum first battery cell temperature t1 is less than the second set temperature T2 and the maximum first battery cell temperature t2 is less than the first set temperature T1, it indicates that if the battery pack is charged at this time, lithium plating will occur inside the battery cells in the battery pack, resulting in serious damage to the battery pack. Therefore, the battery pack cannot be charged in this case, and step 204 is executed; if the BMS determines that the minimum first battery cell temperature t1 is greater than the second set temperature T2, the minimum first battery cell temperature t1 is less than the third set temperature T3, and the maximum first battery cell temperature t2 is less than the first set temperature T1, it indicates that the battery pack can be heated continuously and charged at the same time at this time, and step S14 is executed; if the BMS determines that the minimum first battery cell temperature t1 is greater than or equal to the third set temperature T3, it indicates that the heating of the battery pack needs to be stopped to prevent the battery pack from overheating and malfunctioning, and step S15 is executed; if the BMS determines that the maximum first battery cell temperature t2 is greater than or equal to the first set temperature T1, it indicates that the heating of the battery pack needs to be stopped to prevent the battery pack from overheating and malfunctioning, and step S15 is executed.

[0110] In the embodiments of the present invention, when the BMS determines that the minimum first battery cell temperature t1 is within the third threshold range, whether the maximum first battery cell temperature t2 is less than the first set temperature T2 or the maximum first battery cell temperature t2 is greater than or equal to the first set temperature T2, step S15 is executed. When the BMS determines that the maximum first battery cell temperature t2 is greater than or equal to the first set temperature T2, whether the minimum first battery cell temperature is within the first threshold range, the second threshold range, or the third threshold range, step S15 is executed.

[0111] Step S14, the BMS switches the current state to the state of heating and charging simultaneously.

[0112] In the embodiments of the present invention, the state of heating and charging simultaneously means charging the battery pack while heating the battery pack. After the BMS switches the current state to the state of heating and charging, the heating relay remains closed, and the charging pile can provide a resistance current to the heating resistor to continue heating the battery pack, and the charging pile also provides a battery pack current to the battery pack to charge the battery pack.

[0113] Step S15, the BMS switches the current state to the charging state.

[0114] In an embodiment of the present invention, after the BMS switches the current state to the charging state, it sends a disconnection signal to the heating relay. The heating relay disconnects according to the disconnection signal. At this time, the charging pile only charges the battery pack, and the heating resistor cannot receive the resistance current. Therefore, the heating resistor no longer heats the battery pack.

[0115] In an embodiment of the present invention, Figure 6 is a flowchart of another charging control method provided by an embodiment of the present invention. As Figure 6 shown, before step 102, it further includes:

[0116] Step 302: The BMS sends a closing signal to the heating relay.

[0117] Step 304: The heating relay closes according to the closing signal.

[0118] In an embodiment of the present invention, as Figure 2 shown, the heating relay SW1 closes according to the closing signal, and switches from the open state to the closed state.

[0119] Step 306: The BMS detects whether the heating relay is closed. If so, continue to execute step 102; if not, execute step 308.

[0120] Specifically, if the BMS detects that the heating relay is in the closed state, it indicates that the battery pack can be heated through the Figure 2 shown charging control circuit, and then continue to execute step 102; if the BMS detects that the heating relay is in the open state, it indicates that the heating relay cannot receive the closing signal or the heating relay is damaged, then execute step 308.

[0121] Step 308: The BMS switches the current state to the fault state.

[0122] As an alternative solution, Figure 7 is a flowchart of another state switching method provided by an embodiment of the present invention. As Figure 7 shown, before step 302, it may include:

[0123] Step S21: The BMS obtains multiple second cell temperatures of the battery pack from multiple temperature sensors.

[0124] In an embodiment of the present invention, the battery pack includes multiple cells, each cell corresponds to a temperature sensor, and each temperature sensor can collect the cell temperature of the corresponding cell, so that multiple temperature sensors can collect multiple second cell temperatures.

[0125] Step S22: The BMS screens out the minimum second cell temperature t3 and the maximum second cell temperature t4 from the multiple second cell temperatures.

[0126] Step S23: The BMS determines whether the minimum second cell temperature t3 is within the first threshold range, the second threshold range, or the third threshold range, and determines whether the maximum second cell temperature t4 is greater than or equal to the first set temperature T2. The first threshold range includes a numerical range less than the second set temperature T2, the second threshold range includes a numerical range greater than or equal to the second set temperature T2 and less than the third set temperature T3, and the third threshold range includes a numerical range greater than or equal to the third set temperature T3. If the minimum second cell temperature t3 is within the first threshold range and the maximum second cell temperature t4 is less than the first set temperature T2, then step S24 is executed; if the minimum second cell temperature t3 is within the second threshold range and the maximum second cell temperature t4 is less than the first set temperature T2, then step S25 is executed; if the minimum second cell temperature t3 is within the third threshold range, then step S26 is executed; if the maximum second cell temperature t4 is greater than or equal to the first set temperature T2, then step S26 is executed.

[0127] In the embodiment of the present invention, the minimum second cell temperature t3 being within the first threshold range may include the minimum second cell temperature t3 being greater than or equal to the second set temperature T1; the minimum second cell temperature t3 being within the second threshold range may include the minimum second cell temperature t3 being greater than or equal to the second set temperature T2 and the minimum second cell temperature t3 being less than the third set temperature T3; the minimum second cell temperature t3 being within the third threshold range may include the minimum second cell temperature t3 being greater than or equal to the third set temperature T3.

[0128] The third set temperature T3 should be greater than the second set temperature T2, and the first set temperature T1 should be greater than the third set temperature T3. For example, the first set temperature T1 may include 40 degrees, the second set temperature T2 may include 0 degrees, and the third set temperature T3 may include 15 degrees. In practical applications, the first set temperature T1, the second set temperature T2, and the third set temperature T3 may be set to other values according to different types of cells, and the embodiments of the present invention do not limit this.

[0129] Specifically, if the BMS determines that the minimum second cell temperature t3 is less than the second set temperature T2 and the maximum second cell temperature t4 is less than the first set temperature T1, it indicates that if the battery pack is charged at this time, lithium plating will occur inside the cells in the battery pack, resulting in serious damage to the battery pack. Therefore, the battery pack cannot be charged in this case, and step S24 is executed; if the BMS determines that the minimum second cell temperature t3 is greater than the second set temperature T2, the minimum second cell temperature t3 is less than the third set temperature T3, and the maximum second cell temperature t4 is less than the first set temperature T1, it indicates that the battery pack can continue to be heated and charged at the same time, and step S25 is executed; if the BMS determines that the minimum second cell temperature t3 is greater than or equal to the third set temperature T3, it indicates that the heating of the battery pack needs to be stopped to prevent the battery pack from overheating and malfunctioning, and step S26 is executed; if the BMS determines that the maximum second cell temperature t4 is greater than or equal to the first set temperature T1, it indicates that the heating of the battery pack needs to be stopped to prevent the battery pack from overheating and malfunctioning, and step S26 is executed.

[0130] In an embodiment of the present invention, when the BMS determines that the minimum second cell temperature t3 is within the third threshold range, regardless of whether the maximum second cell temperature t4 is less than the first set temperature T2 or the maximum second cell temperature t4 is greater than or equal to the first set temperature T2, step S26 is executed. When the BMS determines that the maximum second cell temperature t4 is greater than or equal to the first set temperature T2, regardless of whether the minimum second cell temperature is within the first threshold range, the second threshold range, or the third threshold range, step S26 is executed.

[0131] Step S24, the BMS switches the current state to the heating state.

[0132] In an embodiment of the present invention, the heating state refers to the state of heating the battery pack. After the BMS switches the current state to the heating state, it closes the heating relay to enable the heating resistor to heat the battery pack.

[0133] Step S25, the BMS switches the current state to the state of heating and charging simultaneously.

[0134] Step S26, the BMS switches the current state to the charging state.

[0135] In an embodiment of the present invention, Figure 8 is a flowchart of another charging control method provided by an embodiment of the present invention. As Figure 8 shown, before step S21, it further includes:

[0136] Step 402, the VCU sends a feedback signal to the BMS, and the feedback signal includes an allow signal or a prohibit signal.

[0137] Step 404: The BMS determines whether the feedback signal is an enabling signal. If it is, step S21 is executed; if not, step 406 is executed.

[0138] Specifically, if the BMS determines that the feedback signal is an enabling signal, it indicates that the current vehicle state allows charging, and then step S21 is continued; if the BMS determines that the feedback signal is a disabling signal, it indicates that the current vehicle state does not allow charging, and there is a fault or a safety issue with the vehicle, then step 406 is executed.

[0139] Step 406: The BMS switches the current state to the fault state, and the process ends.

[0140] In the embodiment of the present invention, Figure 9 is a flowchart of another charging control method provided by the embodiment of the present invention. As Figure 9 shown, before step 402, it further includes:

[0141] Step 502: The BMS determines whether it has received the access signal sent by the resistance sensor. If it has, step 504 is executed; if not, step 508 is executed.

[0142] In the embodiment of the present invention, the resistance sensor is used to detect whether the charging gun resistance is connected to the charging circuit. If it detects that the charging gun resistance is connected to the charging circuit, it indicates that the charging circuit is connected, and the resistance sensor sends an access signal to the BMS; if it detects that the charging gun resistance is not connected to the circuit, it indicates that the charging circuit is still in the disconnected state, and the resistance sensor will not send an access signal to the BMS.

[0143] Specifically, if the BMS determines that it has received the access signal sent by the resistance sensor, it indicates that the BMS determines that the charging gun has been inserted into the vehicle and the vehicle can be charged, then step 504 is executed; if the BMS determines that it has not received the access signal sent by the resistance sensor, it indicates that the charging gun has not been inserted into the vehicle and the vehicle cannot be charged, then step 508 is executed.

[0144] Step 504: The BMS switches the current mode to the charging mode and sends a notification signal to the VCU.

[0145] As Figure 2 shown, in the charging mode, the negative relay SW2 and the positive relay SW3 of the high-voltage circuit are kept closed.

[0146] Step 506: In response to the notification signal, the VCU detects whether the current vehicle state allows charging and sends a feedback signal.

[0147] In the embodiment of the present invention, if the VCU detects that the current vehicle state allows charging, it takes the allow signal as the feedback signal and sends the feedback signal to the BMS; if the VCU detects that the current vehicle state does not allow charging, it takes the prohibit signal as the feedback signal and sends the feedback signal to the BMS. Among them, the current vehicle state may include battery pack damage, too high battery pack temperature, or the battery pack being in a normal state, etc., and the embodiment of the present invention does not limit this. For example, if the current vehicle state includes the battery pack being in a normal state, the VCU detects that the current vehicle state allows charging; for another example, if the current vehicle state includes battery pack damage, the VCU detects that the current vehicle state does not allow charging.

[0148] Step 508, the BMS switches the current mode to the discharge mode.

[0149] In the embodiment of the present invention, as Figure 2 shown, in the discharge mode, keep the negative high-voltage circuit relay SW2 and the positive high-voltage circuit relay SW3 in the closed state.

[0150] In the technical solution of the embodiment of the present invention, the BMS generates a requested charging voltage according to the total voltage of the battery pack of the battery pack and a set first set voltage, and generates a requested charging current according to the rated power of the heating resistor and the requested charging voltage, so that the charging pile provides a resistance current to the heating resistor and a battery pack current to the battery pack according to the requested charging voltage and the requested charging current, solving the problem that the battery pack current is too large during the heating process and causing damage to the battery pack, thereby avoiding the process of the high-voltage relay disconnecting and closing during the heating process, simplifying the charging process, reducing the failure rate of the charging control circuit, and increasing the service life of the high-voltage relay.

[0151] In the technical solution of the embodiment of the present invention, the BMS detects the inflow current of the battery pack, ensuring that the current actually output by the charging pile is consistent with the requested charging current, avoiding the battery pack current from being too large, and solving the problem of damage to the battery pack caused by charging the battery pack during the heating process, thereby increasing the service life of the battery pack.

[0152] Figure 10 is a schematic structural diagram of a charging control device provided by an embodiment of the present invention. As Figure 10 shown, the device includes: a first generation module 11, a second generation module 12, and a transceiver module 13; the first generation module 11 is connected to the second generation module 12 and the transceiver module 13, and the second generation module 12 is connected to the transceiver module 13.

[0153] The first generation module 11 is used to generate a requested charging voltage according to the total voltage of the battery pack and a set first set voltage; the second generation module 12 is used to generate a requested charging current according to the rated power of the heating resistor and the requested charging voltage; the transceiver module 13 is used to send a requested charging signal to the charging pile, and the requested charging signal includes the requested charging voltage and the requested charging current, so that the charging pile can provide a resistor current to the heating resistor and a battery pack current to the battery pack according to the requested charging voltage and the requested charging current.

[0154] In an embodiment of the present invention, the device further includes: a current acquisition module 14, a first judgment module 15, a first switching module 16, and a second switching module 17; the current acquisition module 14 is connected to the first judgment module 15, and the first judgment module 15 is connected to the first switching module 16 and the second switching module 17.

[0155] The current acquisition module 14 is used to acquire the battery pack current of the battery pack detected by the current sensor; the first judgment module 15 is used to judge whether the battery pack current is greater than or equal to a set threshold; the first switching module 16 is used to switch the current state to a fault state if the first judgment module 15 judges that the battery pack current is greater than or equal to the set threshold; the second switching module 17 is used to switch the current state according to the first cell temperature of the battery pack detected by the temperature sensor if the first judgment module 15 judges that the battery pack current is less than the set threshold.

[0156] In an embodiment of the present invention, Figure 11 is a schematic structural diagram of a second switching module provided by an embodiment of the present invention. As Figure 11 shown, the device includes: a first temperature acquisition sub-module 171, a first temperature screening sub-module 172, a first judgment sub-module 173, and a first switching sub-module 174; the first temperature acquisition sub-module 171 is connected to the first temperature screening sub-module 172, the first temperature screening sub-module 172 is connected to the first judgment sub-module 173, and the first judgment sub-module 173 is connected to the first switching sub-module 174.

[0157] The first temperature acquisition sub-module 171 is used to acquire multiple first cell temperatures of the battery pack from multiple temperature sensors. The first temperature screening sub-module 172 is used to screen out the minimum first cell temperature and the maximum first cell temperature from the multiple first cell temperatures. The first judgment sub-module 173 is used to judge whether the minimum first cell temperature is within the first threshold range, the second threshold range or the third threshold range, and judge whether the maximum first cell temperature is greater than or equal to the first set temperature. The first threshold range includes a numerical range less than the second set temperature, the second threshold range includes a numerical range greater than or equal to the second set temperature and less than the third set temperature, and the third threshold range includes a numerical range greater than or equal to the third set temperature. The first switching sub-module 174 is used to trigger the first judgment module 15 to continue to execute the step of judging whether the battery pack current is greater than or equal to the set threshold if the first judgment sub-module 173 judges that the minimum first cell temperature is within the first threshold range and the maximum first cell temperature is less than the first set temperature; if the first judgment sub-module 173 judges that the minimum first cell temperature is within the second threshold range and the maximum first cell temperature is less than the first set temperature, the current state is switched to the charging while heating state; if the first judgment sub-module 173 judges that the minimum first cell temperature is within the third threshold range, the current state is switched to the charging state; if the first judgment sub-module 173 judges that the maximum first cell temperature is greater than or equal to the first set temperature, the current state is switched to the charging state.

[0158] In an embodiment of the present invention, the device further includes: a detection module 18; the detection module 18 is connected to the first generation module 11 and the first switching module 16.

[0159] The transceiver module 13 is further used to send a closing signal to the heating relay for the heating relay to close according to the closing signal. The detection module 18 is used to detect whether the heating relay is closed. If it is detected that the heating relay is closed, the first generation module 11 is triggered to continue to execute the step of generating a requested charging voltage according to the total battery voltage of the battery pack and the set first set voltage; if it is detected that the heating relay is not closed, the first switching module 16 is triggered to execute the step of switching the current state to the fault state.

[0160] In an embodiment of the present invention, the device further includes: a temperature acquisition module 19, a temperature screening module 20, a second judgment module 21 and a third switching module 22; the temperature acquisition module 19 is connected to the temperature screening module 20, the temperature screening module 20 is connected to the second judgment module 21, and the second judgment module 21 is connected to the third switching module 22.

[0161] The temperature acquisition module 19 is used to acquire multiple second cell temperatures of the battery pack from multiple temperature sensors. The temperature screening module 20 is used to screen out the minimum second cell temperature and the maximum second cell temperature from the multiple second cell temperatures. The second judgment module 21 is used to judge whether the minimum second cell temperature is within the first threshold range, the second threshold range or the third threshold range, and judge whether the maximum second cell temperature is greater than or equal to the first set temperature. The first threshold range includes a numerical range less than the second set temperature, the second threshold range includes a numerical range greater than or equal to the second set temperature and less than the third set temperature, and the third threshold range includes a numerical range greater than or equal to the third set temperature. The third switching module 22 is used to switch the current state to the heating state if the second judgment module 21 judges that the minimum second cell temperature is within the first threshold range and the maximum second cell temperature is less than the first set temperature.

[0162] In an embodiment of the present invention, the third switching module 22 is further used to switch the current state to the charging while heating state if the second judgment module 21 judges that the minimum second cell temperature is within the second threshold range and the maximum second cell temperature is less than the first set temperature; switch the current state to the charging state if the second judgment module 21 judges that the minimum second cell temperature is within the third threshold range; and switch the current state to the charging state if the second judgment module 21 judges that the maximum second cell temperature is greater than or equal to the first set temperature.

[0163] In an embodiment of the present invention, the device further includes: a third judgment module 23; the third judgment module 23 is connected to the transceiver module 13, the first switching module 16 and the temperature acquisition module 19.

[0164] The transceiver module 13 is further used to receive a feedback signal sent by the VCU, and the feedback signal includes an allow signal or a prohibit signal; the third judgment module 23 is used to judge whether the feedback signal is an allow signal; if it is judged that the feedback signal is a prohibit signal, trigger the first switching module 16 to execute the step of switching the current state to the fault state; if it is judged that the feedback signal is an allow signal, trigger the temperature acquisition module 19 to execute the step of acquiring multiple second cell temperatures of the battery pack from multiple temperature sensors.

[0165] In an embodiment of the present invention, the device further includes: a fourth judgment module 24 and a fourth switching module 25; the fourth judgment module 24 is connected to the fourth switching module 25 and the transceiver module 13.

[0166] The fourth determination module 24 is configured to determine whether an access signal sent by the resistance sensor is received. The fourth switching module 25 is configured to switch the current mode to the discharging mode if the fourth determination module 24 determines that the access signal sent by the resistance sensor is not received; and switch the current mode to the charging mode if the fourth determination module 24 determines that the access signal sent by the resistance sensor is received. The transceiver module 13 is further configured to send a determination signal to the VCU if the fourth determination module 24 determines that the access signal sent by the resistance sensor is received, so that the VCU can detect whether the current vehicle state allows charging in response to the notification signal and send a feedback signal.

[0167] In the technical solution of the embodiment of the present invention, the BMS generates a requested charging voltage based on the total voltage of the battery pack and a set first set voltage, and generates a requested charging current based on the rated power of the heating resistor and the requested charging voltage, so that the charging pile provides a resistor current to the heating resistor and a battery pack current to the battery pack according to the requested charging voltage and the requested charging current, solving the problem that the battery pack current is too large during the heating process and causing damage to the battery pack, thereby avoiding the process of the high-voltage relay disconnecting and closing during the heating process, simplifying the charging process, reducing the failure rate of the charging control circuit, and increasing the service life of the high-voltage relay.

[0168] The embodiment of the present invention provides a computer-readable storage medium, which includes a stored program. When the program runs, it controls the BMS where the computer-readable storage medium is located to execute the embodiment of the above-mentioned charging control method.

[0169] The embodiment of the present invention provides a BMS, including: one or more processors; a memory; and one or more computer programs, where the one or more computer programs are stored in the memory, and the one or more computer programs include instructions. When the instructions are executed by the BMS, the BMS is caused to execute the embodiment of the above-mentioned charging control method.

[0170] Figure 12 It is a schematic diagram of a BMS provided by an embodiment of the present invention. As Figure 12 shown, the BMS 10 of this embodiment includes: a processor 31, a memory 32, and a computer program 33 stored in the memory 31 and executable on the processor 31. When the computer program 33 is executed by the processor 31, it implements the charging control method in the embodiment. To avoid repetition, details are not described here one by one.

[0171] The BMS 10 includes, but is not limited to, a processor 31 and a memory 32. Those skilled in the art can understand that Figure 12This is only an example of BMS10 and does not constitute a limitation on BMS10. It may include more or fewer components than those shown in the figure, or combine certain components, or different components. For example, BMS10 may also include input / output devices, network access devices, buses, etc.

[0172] The so-called processor 31 may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0173] The memory 32 may be an internal storage unit of BMS10, such as the hard disk or memory of BMS10. The memory 32 may also be an external storage device of BMS10, such as a plug-in hard disk equipped on BMS10, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. Further, the memory 32 may also include both the internal storage unit and the external storage device of BMS10. The memory 32 is used to store computer programs and other programs and data required by the network device. The memory 32 may also be used to temporarily store data that has been output or is to be output. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the above-described systems, devices, and units can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein. In several embodiments provided by the present invention, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other may be through some interfaces, and the indirect couplings or communication connections of the devices or units may be in electrical, mechanical, or other forms.

[0174] The unit described as a separation component may or may not be physically separated. The component shown as a unit may or may not be a physical unit, that is, it may be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0175] In addition, each functional unit in various embodiments of the present invention may be integrated in a processing unit, may exist separately as individual physical units, or two or more units may be integrated in one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of hardware plus software functional units.

[0176] The above-mentioned integrated units implemented in the form of software functional units can be stored in a computer-readable storage medium. The above-mentioned software functional units stored in a computer-readable storage medium include several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to execute some steps of the methods described in various embodiments of the present invention. The aforementioned computer-readable storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM), random access memories (RAM), magnetic disks, or optical discs that can store program codes.

[0177] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A charging control method, characterized in that, The method is applied to a battery management system (BMS); the method includes: Generating a requested charging voltage based on the total voltage of the battery pack and a set first set voltage; Generating a requested charging current based on the rated power of the heating resistor and the requested charging voltage; Sending a requested charging signal to a charging pile, the requested charging signal including the requested charging voltage and the requested charging current, for the charging pile to provide a resistor current to the heating resistor and a battery pack current to the battery pack according to the requested charging voltage and the requested charging current.

2. The method according to claim 1, wherein The method further includes: Obtaining the battery pack current of the battery pack detected by a current sensor; Determining whether the battery pack current is greater than or equal to a set threshold; If the battery pack current is greater than or equal to the set threshold, switching the current state to a fault state; If the battery pack current is less than the set threshold, switching the current state according to the first cell temperature of the battery pack detected by a temperature sensor.

3. The method according to claim 2, wherein The switching the current state according to the first cell temperature of the battery pack detected by a temperature sensor includes: Obtaining multiple first cell temperatures of the battery pack from multiple temperature sensors; Selecting the minimum first cell temperature and the maximum first cell temperature from the multiple first cell temperatures; Determining whether the minimum first cell temperature is within a first threshold range, a second threshold range, or a third threshold range, and determining whether the maximum first cell temperature is greater than or equal to a first set temperature, the first threshold range including a numerical range less than a second set temperature, the second threshold range including a numerical range greater than or equal to the second set temperature and less than a third set temperature, and the third threshold range including a numerical range greater than or equal to the third set temperature; If the minimum first cell temperature is within the first threshold range and the maximum first cell temperature is less than the first set temperature, continuing to perform the step of determining whether the battery pack current is greater than or equal to the set threshold; If the minimum first cell temperature is within the second threshold range and the maximum first cell temperature is less than the first set temperature, switching the current state to a charging-while-heating state; If the minimum first cell temperature is within the third threshold range, switching the current state to a charging state; If the maximum first cell temperature is greater than or equal to the first set temperature, switching the current state to a charging state.

4. The method according to claim 1, characterized in that Before generating the requested charging voltage based on the total voltage of the battery pack and the set first set voltage, it further includes: Sending a closing signal to a heating relay for the heating relay to close according to the closing signal; Detecting whether the heating relay is closed; If the heating relay is closed, continuing to perform the step of generating the requested charging voltage based on the total voltage of the battery pack and the set first set voltage; If the heating relay is not closed, switching the current state to a fault state.

5. The method according to claim 4, wherein Before sending the closing signal to the heating relay for the heating relay to close according to the closing signal, it further includes: Obtain multiple second cell temperatures of the battery pack from multiple of the temperature sensors; Screen out the minimum second cell temperature and the maximum second cell temperature from the multiple second cell temperatures; If the minimum second cell temperature is within a first threshold range and the maximum second cell temperature is less than the first set temperature, then switch the current state to a heating state, where the first threshold range includes a numerical range less than the second set temperature.

6. The method according to claim 5, characterized in that The method further includes: If the minimum second cell temperature is within a second threshold range and the maximum second cell temperature is less than the first set temperature, then switch the current state to a charging while heating state, where the second threshold range includes a numerical range greater than or equal to the second set temperature and less than the third set temperature; If the minimum second cell temperature is within the third threshold range, then switch the current state to a charging state, where the third threshold range includes a numerical range greater than or equal to the third set temperature; If the maximum second cell temperature is greater than or equal to the first set temperature, then switch the current state to a charging state.

7. The method according to claim 5, wherein Before obtaining multiple second cell temperatures of the battery pack from multiple of the temperature sensors, it further includes: Receive a feedback signal sent by a vehicle control unit VCU, where the feedback signal includes an allow signal or a prohibit signal; Determine whether the feedback signal is the allow signal; If the feedback signal is the prohibit signal, then switch the current state to a fault state; If the feedback signal is the allow signal, then continue to execute the step of obtaining multiple second cell temperatures of the battery pack from multiple of the temperature sensors.

8. The method according to claim 7, wherein Before receiving the feedback signal sent by the vehicle control unit VCU, it further includes: Determine whether an access signal sent by the resistance sensor is received; If the access signal sent by the resistance sensor is not received, then switch the current mode to a discharge mode; If the access signal sent by the resistance sensor is received, then switch the current mode to a charging mode and send a notification signal to the VCU for the VCU to detect whether the current vehicle state allows charging in response to the notification signal and send the feedback signal.

9. A charging control system, characterized in that, The system includes: a BMS; The BMS is configured to generate a requested charging voltage based on the total voltage of the battery pack and a set first set voltage; generate a requested charging current based on the rated power of the heating resistor and the requested charging voltage; send a requested charging signal to a charging pile, where the requested charging signal includes the requested charging voltage and the requested charging current; for the charging pile to provide a resistor current to the heating resistor and a battery pack current to the battery pack according to the requested charging voltage and the requested charging current.

10. A vehicle, characterized in that, Includes: The charging control system according to claim 9.

11. A charging control device, characterized in that, Includes: A first generation module configured to generate a requested charging voltage based on the total voltage of the battery pack and a set first set voltage; A second generation module configured to generate a requested charging current based on the rated power of the heating resistor and the requested charging voltage; A transceiver module for sending a charging request signal to a charging pile, the charging request signal including the requested charging voltage and the requested charging current, so that the charging pile can provide a resistance current to the heating resistor and a battery pack current to the battery pack according to the requested charging voltage and the requested charging current.

12. A BMS, characterized in that, Comprising: One or more processors; A memory; And one or more computer programs, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions that, when executed by the BMS, cause the BMS to execute the charging control method according to any one of claims 1 to 8.

13. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program runs, it controls the BMS where the computer-readable storage medium is located to execute the charging control method according to any one of claims 1 to 8.

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