Battery heating system, control method thereof, battery charging and discharging system, and vehicle

Abstract

The application discloses a battery heating system and a control method thereof, a battery charging and discharging system and a vehicle. The battery heating control method comprises the following steps: the battery heating system comprises a thermistor unit and a pure resistance heating unit for heating a battery pack, and a first contactor and a second contactor, the thermistor unit, the first contactor and the battery pack are connected in series, and the pure resistance heating unit is connected in parallel with the first contactor after being connected with the second contactor in series, the control method comprises the following steps: acquiring a state parameter of the battery pack; and controlling the switching state of the first contactor and the second contactor according to the state parameter of the battery pack. By using the method, the heating power of the battery heating system can be actively adjusted according to the state parameter of the battery pack, so that the heating efficiency is improved, and the heating time is shortened.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a battery heating system and its control method, a battery charging and discharging system, and a vehicle. Background Technology

[0002] In related technologies, battery heating systems heat the battery by connecting a thermistor unit and a pure resistance heating unit in series. When the temperature of the thermistor unit reaches its Curie point, the resistance value of the thermistor unit will increase rapidly with the increase of temperature, thereby preventing the risk of dry burning and achieving the purpose of passively protecting the battery heating system. However, when the resistance value of the thermistor unit increases rapidly with the increase of temperature, it will also cause a decrease in heating power and affect heating efficiency. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one objective of this invention is to propose a control method for a battery heating system. This method can actively adjust the heating power of the battery heating system based on the state parameters of the battery pack, thereby improving heating efficiency and shortening heating time.

[0004] The second objective of this invention is to provide a computer storage medium.

[0005] The third objective of this invention is to provide a battery heating system.

[0006] The fourth objective of this invention is to provide a battery charging and discharging system.

[0007] The fifth objective of this invention is to provide a vehicle.

[0008] To address the aforementioned problems, a first aspect of the present invention provides a control method for a battery heating system. The battery heating system includes a thermistor unit and a pure resistance heating unit for heating the battery pack, as well as a first contactor and a second contactor. The thermistor unit, the first contactor, and the battery pack are connected in series. The pure resistance heating unit is connected in series with the second contactor and then in parallel with the first contactor. The control method includes: acquiring state parameters of the battery pack; and controlling the switching states of the first contactor and the second contactor according to the state parameters of the battery pack.

[0009] According to the battery heating system control method of the present invention, based on the circuit connection method of the battery heating system, the switching states of the first contactor and the second contactor are controlled by the state parameters of the battery pack, so that the thermistor unit can work alone or the thermistor unit and the pure resistance heating unit can work together. This adjusts the heating power of the battery heating system on the battery pack during the heating process. Moreover, compared with the method of heating by connecting the thermistor unit and the pure resistance heating unit in series, the method of adjusting the heating power by the state parameters of the battery pack based on the circuit connection method of the thermistor unit and the pure resistance heating unit in this application means that the battery heating system is no longer limited to the passive protection of the thermistor unit reaching the Curie point temperature, thereby improving heating efficiency and shortening heating time.

[0010] In some embodiments, controlling the switching states of the first contactor and the second contactor according to the state parameters of the battery pack includes: determining that the state parameters of the battery pack meet the charging or discharging heating conditions, and controlling the second contactor to close so that the thermistor unit and the pure resistance heating unit jointly heat the battery pack.

[0011] In some embodiments, the state parameters of the battery pack include at least the remaining charge value of the battery pack, the minimum temperature value and the maximum temperature value of the battery pack during charging and discharging. Determining that the state parameters of the battery pack meet the charging / discharging heating conditions and controlling the second contactor to close includes: the battery pack is in a discharging state, determining that the remaining charge value is greater than a first preset charge value and the minimum temperature value is less than a first preset temperature and the maximum temperature value is less than a second preset temperature, and controlling the second contactor to close, wherein the second preset temperature is greater than the first preset temperature.

[0012] In some embodiments, the state parameters of the battery pack include at least the minimum temperature value and the maximum temperature value of the battery pack during the charging and discharging process. Determining that the state parameters of the battery pack meet the charging / discharging heating conditions and controlling the second contactor to close includes: the battery pack is in a charging state, determining that the minimum temperature value is less than a third preset temperature and the maximum temperature value is less than a fourth preset temperature, and controlling the second contactor to close, wherein the fourth preset temperature is greater than the third preset temperature.

[0013] In some embodiments, the thermistor unit is used to heat the surface of the battery pack. After controlling the second contactor to close, the switching states of the first contactor and the second contactor are controlled according to the state parameters of the battery pack. The method further includes: determining that the state parameters of the battery pack meet the heating limitation conditions, and controlling the first contactor to alternately close and open.

[0014] In some embodiments, when it is determined that the state parameters of the battery pack meet the heating limitation conditions, the first contactor is alternately controlled to close and open, including: calculating the temperature difference between the maximum temperature value of the battery pack during the charging and discharging process and the minimum temperature value of the battery pack during the charging and discharging process; determining that the temperature difference is greater than a preset temperature difference threshold, and controlling the first contactor to alternately close and open.

[0015] In some embodiments, controlling the first contactor to alternately close and open includes: a calculation step, calculating the temperature difference between the maximum temperature value and the minimum temperature value of the battery pack during charging and discharging; a first determination step, determining a target conduction duration based on the temperature difference; a control closing step, controlling the first contactor to close for the target conduction duration; a second determination step, determining a target disconnection duration based on the minimum temperature value; a control disconnection step, controlling the first contactor to disconnect for the target disconnection duration; and cyclically executing the calculation step, the first determination step, the control closing step, the second determination step, and the control disconnection step until the state parameters of the battery pack meet the heating exit condition, at which point both the first contactor and the second contactor are controlled to disconnect.

[0016] In some embodiments, controlling both the first contactor and the second contactor to disconnect until the state parameters of the battery pack meet the heating exit condition includes: determining that the minimum temperature value is greater than a third preset temperature and controlling both the first contactor and the second contactor to disconnect; or determining that the maximum temperature value is greater than a fourth preset temperature and controlling both the first contactor and the second contactor to disconnect.

[0017] In some embodiments, when the battery pack is in a discharging state, the control to disconnect both the first contactor and the second contactor until the state parameters of the battery pack meet the heating exit condition further includes: determining that the remaining charge value of the battery pack is less than a second preset charge value, and then controlling both the first contactor and the second contactor to disconnect.

[0018] In some embodiments, the temperature difference is proportional to the target conduction duration.

[0019] In some embodiments, the minimum temperature value is inversely proportional to the target disconnection time.

[0020] A second aspect of the present invention provides a computer storage medium having a computer program stored thereon, wherein the computer program is executed by a processor using the control method of the battery heating system described in the above embodiments.

[0021] A third aspect of the present invention provides a battery heating system, comprising: a thermistor unit and a pure resistance heating unit for heating the battery pack; a first contactor and a second contactor, wherein the thermistor unit, the first contactor, and the battery pack are connected in series, and the pure resistance heating unit is connected in series with the second contactor and then in parallel with the first contactor; and a battery manager connected to the first contactor and the second contactor, wherein the battery management system is used to execute the control method of the battery heating system described in the above embodiment.

[0022] According to the battery heating system of the present invention, by executing the control method of the battery heating system of the above embodiment, the heating power of the battery heating system can be actively adjusted by the state parameters of the battery pack, which helps to improve heating efficiency and shorten heating time.

[0023] A fourth aspect of the present invention provides a battery charging and discharging system, including the battery heating system described in the above embodiments.

[0024] According to the battery charging and discharging system of the present invention, the heating power of the battery heating system can be actively adjusted by the state parameters of the battery pack, which helps to improve heating efficiency and shorten heating time.

[0025] A fifth aspect of the present invention provides a vehicle including the battery charging and discharging system described in the above embodiments.

[0026] According to the vehicle of the present invention, the heating power of the battery heating system can be actively adjusted by the state parameters of the battery pack, which helps to improve heating efficiency and shorten heating time.

[0027] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0029] Figure 1 This is a flowchart of a battery heating system control method according to an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of a battery heating system according to an embodiment of the present invention;

[0031] Figure 3 This is a structural block diagram of a battery charging and discharging system according to an embodiment of the present invention;

[0032] Figure 4 This is a structural block diagram of a vehicle according to an embodiment of the present invention.

[0033] Figure label:

[0034] Battery heating system 10; Battery charging and discharging system 20; Vehicle 30;

[0035] Thermistor unit 1; pure resistance heating unit 2; first contactor 3; second contactor 4; battery pack 5; battery manager 6; negative contactor 7; positive contactor 8. Detailed Implementation

[0036] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention are described in detail below.

[0037] To address the aforementioned problems, a first aspect of the present invention provides a battery heating system control method. This method allows for the active adjustment of the battery pack's heating power based on state parameters, resulting in more accurate adjustment of the battery pack's heating power.

[0038] In an embodiment, such as Figure 1 As shown, the battery heating system 10 includes a thermistor unit 1 and a pure resistance heating unit 2 for heating the battery pack, as well as a first contactor 3 and a second contactor 4. The thermistor unit 1, the first contactor 2, and the battery pack 5 are connected in series in sequence. The pure resistance heating unit 2 is connected in series with the second contactor 4 and then connected in parallel with the first contactor 3.

[0039] The following is for reference. Figure 2 A battery heating system control method according to an embodiment of the present invention is described, such as... Figure 2 As shown, the method includes at least steps S1 to S2.

[0040] Step S1: The battery manager collects the status parameters of the battery pack.

[0041] Step S2: Control the switching states of the first and second contactors according to the state parameters of the battery pack.

[0042] Specifically, existing battery heating systems heat the battery by connecting a thermistor unit and a pure resistance heating unit in series. When the temperature of the thermistor unit reaches its Curie point, its resistance increases rapidly with rising temperature, thus preventing the risk of dry burning and achieving passive protection of the battery heating system. However, the rapid increase in the thermistor unit's resistance with temperature also reduces heating power and affects heating efficiency. To address this issue, this application controls the switching states of the first and second contactors based on the battery pack's state parameters. By combining these parameters with the switching state control of the first and second contactors to be closed or open, the thermistor unit can operate independently. Alternatively, the thermistor unit and the pure resistance heating unit can work together. Utilizing the characteristic that the thermistor unit's resistance changes with temperature, the heating temperature of the thermistor unit can be adjusted, thereby changing its resistance value. This, in turn, adjusts the heating power of the battery heating system on the battery pack during the heating process. Compared to the method of connecting the thermistor unit and the pure resistance heating unit in series, this application uses a circuit connection method based on the thermistor unit and the pure resistance heating unit to adjust the heating power according to the battery pack's state parameters. This means the battery heating system is no longer limited to passive protection based on the thermistor unit reaching its Curie point temperature, thus improving heating efficiency, shortening heating time, and allowing for more accurate adjustment of the battery pack's heating power.

[0043] For example, when the thermistor unit is a positive temperature coefficient thermistor unit, the thermistor unit is placed on the surface of the battery pack and close to the external environment, and the pure resistance heating unit is placed inside the battery pack, the state parameters of the battery pack can be the temperature information of the battery pack. When the state parameters of the battery pack indicate that the surface temperature of the battery pack is low and the internal temperature of the battery pack is high, the switch state of the first contactor is controlled to be closed and the switch state of the second contactor is controlled to be open, so that the thermistor unit heats the surface of the battery pack independently. At this time, the resistance value of the thermistor is small, thereby improving the heating effect of the battery heating system on the battery pack during the heating process. The heating power is increased to quickly raise the surface temperature of the battery pack; or when the overall temperature of the battery pack is detected to be low through the state parameters of the battery pack, the switch state of the second contactor is controlled to be closed so that the pure resistance heating unit and the thermistor unit can heat the battery pack together, thereby increasing the overall temperature of the battery pack; or when the overall temperature of the battery pack is detected to be low and the surface temperature of the battery pack is very low through the state parameters of the battery pack, the switch state of the first contactor and the second contactor is controlled to be closed, thereby increasing the heating power of the thermistor unit to the battery pack during the heating process, thereby increasing the surface temperature while increasing the overall temperature of the battery pack.

[0044] According to the battery heating system control method of the present invention, based on the circuit connection method of the battery heating system, the switching states of the first contactor and the second contactor are controlled by the state parameters of the battery pack, so that the thermistor unit can work alone or the thermistor unit and the pure resistance heating unit can work together. This adjusts the heating power of the battery heating system on the battery pack during the heating process. Moreover, compared with the method of heating by connecting the thermistor unit and the pure resistance heating unit in series, the method of adjusting the heating power by the state parameters of the battery pack based on the circuit connection method of the thermistor unit and the pure resistance heating unit in this application means that the battery heating system is no longer limited to the passive protection of the thermistor unit reaching the Curie point temperature, thereby improving heating efficiency and shortening heating time.

[0045] In some embodiments, controlling the switching states of the first and second contactors based on the state parameters of the battery pack includes: determining that the state parameters of the battery pack meet the charging or discharging heating conditions, and controlling the second contactor to close so that the thermistor unit and the pure resistance heating unit jointly heat the battery pack. That is, the battery manager detects the state parameters of the battery pack and determines whether the state parameters meet the charging or discharging heating conditions, thereby determining whether to control the thermistor unit and the pure resistance heating unit to jointly heat the battery pack during the discharging process. If the state parameters meet the charging or discharging heating conditions, the second contactor is controlled to close so that the thermistor unit and the pure resistance heating unit jointly heat the battery pack.

[0046] In some embodiments, the state parameters of the battery pack include at least the remaining charge value of the battery pack, the minimum temperature value and the maximum temperature value of the battery pack during the charging and discharging process. Determining that the state parameters of the battery pack meet the charging / discharging heating conditions and controlling the second contactor to close includes: the battery pack is in a discharging state, determining that the remaining charge value is greater than a first preset charge value and the minimum temperature value is less than a first preset temperature and the maximum temperature value is less than a second preset temperature, and controlling the second contactor to close, wherein the second preset temperature is greater than the first preset temperature.

[0047] The first preset temperature can be understood as a temperature value set based on the minimum temperature of the battery pack in the discharge state, which affects the performance of the battery pack. For example, the first preset temperature is 5℃, and there is no restriction on it. The second preset temperature can be understood as a temperature value set based on the maximum temperature of the battery pack in the discharge state, which affects the performance of the battery pack. For example, the second preset temperature is 30℃, and there is no restriction on it.

[0048] Specifically, when the battery pack is discharging, the battery manager collects the remaining charge value of the battery pack, as well as the minimum and maximum temperature values ​​during the discharge process. It then determines whether the remaining charge value, minimum temperature value, and maximum temperature value meet the discharge heating conditions, thereby determining whether the thermistor unit and the pure resistance heating unit should be controlled to heat the battery pack during the discharge process. If the remaining charge value is greater than a first preset charge value (which can be 10%), it means that the remaining charge can provide the current for the thermistor unit and the pure resistance heating unit to operate during the discharge process, and the remaining charge can meet the discharge requirements of the battery pack. If the minimum temperature value is less than the first preset temperature and the maximum temperature value is less than the second preset temperature, it means that the overall temperature of the battery pack is low during the discharge process, and the battery pack needs to be heated to ensure the discharge performance of the battery pack at low temperatures. After meeting the above discharge heating conditions, the second contactor is controlled to close, so that the thermistor unit and the pure resistance heating unit can jointly heat the battery pack, thereby increasing the overall temperature of the battery pack. In addition, if the minimum temperature value, maximum temperature value, and remaining charge value do not meet the discharge heating conditions, it is determined that the battery pack will not be heated during the discharge process. Therefore, by actively adjusting the heating temperature of the thermistor unit through the state parameters of the battery pack in this application, the battery heating system is no longer limited to passive protection when the temperature of the thermistor unit reaches the Curie point, thereby improving heating efficiency and shortening heating time.

[0049] In this embodiment, after the vehicle is powered by high voltage, the battery pack is in a discharging state, and the negative contactor and the main contactor are closed to supply power to the load.

[0050] In some embodiments, the state parameters of the battery pack include at least the minimum temperature value and the maximum temperature value of the battery pack during the charging and discharging process. Determining that the state parameters of the battery pack meet the charging / discharging heating conditions and controlling the second contactor to close includes: the battery pack is in a charging state, determining that the minimum temperature value is less than a third preset temperature and the maximum temperature value is less than a fourth preset temperature, and controlling the second contactor to close, wherein the fourth preset temperature is greater than the third preset temperature.

[0051] The third preset temperature can be understood as a temperature value set based on the minimum temperature of the battery pack during charging, which affects the battery pack's performance. For example, the third preset temperature is 0℃, and there is no restriction on it. The fourth preset temperature can be understood as a temperature value set based on the maximum temperature of the battery pack during charging, which affects the battery pack's performance. For example, the fourth preset temperature is 15℃, and there is no restriction on it.

[0052] Specifically, when the battery pack is charging, the battery manager collects the minimum and maximum temperature values ​​of the battery pack during the charging process and determines whether the minimum and maximum temperature values ​​meet the charging heating conditions. This determines whether the thermistor unit and the pure resistance heating unit should be controlled to heat the battery pack during charging. Specifically, if the minimum temperature value is less than a third preset temperature and the maximum temperature value is less than a fourth preset temperature, it indicates that the overall temperature of the battery pack is low during charging, and heating is required to ensure the charging performance of the battery pack at low temperatures. After meeting the above charging heating conditions, the second contactor is controlled to close, allowing the thermistor unit and the pure resistance heating unit to jointly heat the battery pack, thereby increasing the overall temperature of the battery pack. Conversely, if the minimum and maximum temperature values ​​do not meet the charging heating conditions, it is determined that the battery pack will not be heated during charging. Therefore, this application actively adjusts the heating temperature of the thermistor unit through the state parameters of the battery pack, so that the battery heating system is no longer limited to passive protection based on the thermistor unit reaching the Curie point temperature, thus improving heating efficiency and shortening heating time.

[0053] In this embodiment, the battery pack enters the charging state by combining the signal interaction between the vehicle end and the charging pile end, at which time the negative contactor and the positive contactor are closed.

[0054] In some embodiments, the thermistor unit is used to heat the surface of the battery pack. After controlling the second contactor to close, the switching states of the first and second contactors are controlled according to the state parameters of the battery pack. The method further includes: determining that the state parameters of the battery pack meet the heating limit conditions, and controlling the first contactor to alternately close and open. That is, to ensure the safety of the battery pack during the charging and discharging heating process, and to avoid the problem of excessive temperature difference affecting battery pack performance, this application pre-sets heating limit conditions for the thermistor unit and the pure resistance heating unit to heat the battery pack. During the heating process of the battery pack by the thermistor unit and the pure resistance heating unit under charging and discharging heating, when the temperature difference reaches the heating limit conditions, the first contactor is controlled to alternately close and open through the state parameters, so that the surface temperature of the battery pack near the external environment increases rapidly, thereby reducing the temperature difference, ensuring the safety of the battery pack during the charging and discharging heating process, and avoiding the problem of excessive temperature difference affecting battery pack performance.

[0055] In some embodiments, when it is determined that the state parameters of the battery pack meet the heating limitation conditions, the first contactor is alternately controlled to close and open, including: calculating the temperature difference between the maximum temperature value of the battery pack during the charging and discharging process and the minimum temperature value of the battery pack during the charging and discharging process; determining that the temperature difference is greater than a first preset temperature difference threshold, and controlling the first contactor to alternately close and open.

[0056] The first preset temperature difference threshold can be understood as the maximum temperature difference that the battery pack can tolerate under certain operating conditions. The first preset temperature difference threshold may be different during the charging or discharging process of the battery pack.

[0057] Specifically, the thermistor unit in this application is disposed on the surface of the battery pack and close to the external environment. The surface of the battery pack has a relatively fast heat transfer rate, making it easier for the surface temperature of the battery pack near the external environment to decrease. The pure resistance heating unit is disposed inside the battery pack. Due to the good insulation effect inside the battery pack, and the cell stacking and structural layout, when the thermistor unit and the pure resistance heating unit jointly heat the battery pack, the temperature of the surface of the battery pack near the external environment rises slowly, while the internal temperature of the battery pack rises rapidly. This results in an excessively large temperature difference between the maximum and minimum temperature values. Therefore, to ensure the safety of the battery pack during the charging and discharging heating process, and to avoid the problem of excessive temperature difference affecting battery pack performance, this application pre-sets limitations on the thermistor unit and the pure resistance heating unit's influence on the battery pack. The heating limitation conditions are set during the heating process of the battery pack by the thermistor unit and the pure resistance heating unit under charge and discharge heating. When the temperature difference reaches the heating limit condition, the first contactor is controlled to alternately close and open. This increases the surface temperature of the battery pack near the external environment, thereby reducing the temperature difference. Specifically, the temperature difference between the maximum and minimum temperatures of the battery pack during charge and discharge is calculated. During the charge and discharge heating process, the temperature difference is continuously checked to see if it exceeds a preset temperature difference threshold. If the temperature difference exceeds the first preset temperature difference threshold, it indicates that the temperature difference of the battery pack is too large and affects its performance or safety. Therefore, the first contactor is controlled to alternately close and open. When the first contactor is closed, the heating power of the thermistor unit during the heating process is increased, causing the surface temperature of the battery pack near the external environment to rise rapidly, thereby reducing the temperature difference. This ensures the safety of the battery pack during charge and discharge heating and avoids the problem of excessive temperature difference affecting battery pack performance. Therefore, this application adjusts the temperature difference by adjusting the state parameters to ensure the safety of the battery pack during the charging and discharging heating process and to avoid the problem of excessive temperature difference affecting battery pack performance. Furthermore, compared to heating the battery by separately setting up a pure resistance heating unit or a thermistor unit, this method can effectively control the battery temperature difference during the heating process, improve consistency, and extend battery life.

[0058] It should be noted that after controlling the first contactor to close, the first contactor is then controlled to open, and the second contactor is closed, thereby increasing the heating rate of the overall battery pack temperature.

[0059] In this embodiment, during the alternating closing and opening of the first contactor, the second contactor can also be closed or opened without restriction. When the first contactor is closed and the second contactor is closed, the thermistor unit and the pure resistance heating unit together heat the battery pack.

[0060] In some embodiments, controlling the first contactor to alternately close and open includes the following steps:

[0061] The calculation steps involve calculating the temperature difference between the maximum and minimum temperatures of the battery pack during the charging and discharging process.

[0062] The first step is to determine the target conduction duration based on the temperature difference. In this application, the correspondence between temperature difference and conduction duration is calibrated experimentally, and the corresponding target conduction duration can be retrieved based on the temperature difference.

[0063] The closing steps are controlled, and the target conduction time of the first contactor is controlled so that the thermistor unit conducts the target conduction time for heating the battery pack, thereby significantly increasing the surface temperature of the battery pack.

[0064] The second step is to determine the target disconnection time based on the minimum temperature value.

[0065] The disconnection step is controlled by controlling the target disconnection time of the first contactor. At this time, the second contactor is closed so that the thermistor unit and the pure resistance heating unit can heat the battery pack together, thereby ensuring the overall temperature rise rate of the battery pack.

[0066] The calculation step, the first determination step, the control closing step, the second determination step, and the control opening step are executed repeatedly until the state parameters of the battery pack meet the heating exit condition. Then, the first contactor and the second contactor are both opened, thereby controlling the thermistor unit and the pure resistance heating unit to stop heating the battery pack.

[0067] In some embodiments, the first and second contactors are disconnected until the battery pack's state parameters meet the heating exit condition. Specifically, if the minimum temperature value is determined to be greater than a fifth preset temperature, it indicates that the battery pack temperature is high and heating to improve charge / discharge performance is unnecessary. Therefore, the first and second contactors are disconnected, thereby stopping the thermistor unit and the pure resistance heating unit from heating the battery pack. Alternatively, if the maximum temperature value is determined to be greater than a sixth preset temperature, it also indicates that the battery pack temperature is high and heating to improve charge / discharge performance is unnecessary. Therefore, the first and second contactors are disconnected, thereby stopping the thermistor unit and the pure resistance heating unit from heating the battery pack. Or, if the temperature difference is determined to be greater than a second preset temperature difference threshold, indicating an excessively large temperature difference, the first and second contactors are disconnected, thereby stopping the thermistor unit and the pure resistance heating unit from heating the battery pack. Thus, the minimum temperature value, the maximum temperature value, and the temperature difference are used to control the thermistor unit and the pure resistance heating unit to stop heating the battery pack.

[0068] The fifth preset temperature can be understood as a temperature value set based on the minimum temperature of the battery pack no longer affecting its performance. For example, the fifth preset temperature could be 15 degrees Celsius, and there are no restrictions on the comparison. The sixth preset temperature can be understood as a temperature value set based on the maximum temperature of the battery pack no longer affecting its performance. For example, the sixth preset temperature could be 40 degrees Celsius, and there are no restrictions on the comparison.

[0069] In some embodiments, when the battery pack is in a discharging state, the first and second contactors are both disconnected until the battery pack's state parameters meet the heating exit condition. Specifically, if the remaining charge of the battery pack is determined to be less than a second preset charge value, it indicates that the remaining charge is insufficient to provide the current required for the thermistor unit and the pure resistance heating unit to operate during the discharge process, and that the remaining charge cannot meet the battery pack's discharge requirements. Therefore, the first and second contactors are disconnected, thereby stopping the thermistor unit and the pure resistance heating unit from heating the battery pack. Thus, the remaining charge value can also be used to control the thermistor unit and the pure resistance heating unit to stop heating the battery pack.

[0070] In some embodiments, the temperature difference is proportional to the target conduction time; that is, the greater the temperature difference, the longer the target conduction time for controlling the first contactor to close, thereby extending the heating time of the thermistor unit on the battery pack and thus significantly increasing the surface temperature of the battery pack.

[0071] In some embodiments, the minimum temperature value is inversely proportional to the target disconnection time, that is, the smaller the minimum temperature value, the longer the target disconnection time, thereby rapidly increasing the minimum temperature value of the battery pack.

[0072] A second aspect of the present invention provides a computer storage medium having a computer program stored thereon, wherein the computer program is executed by a processor using the control method of the battery heating system described above.

[0073] A third aspect of the present invention provides a battery heating system, such as... Figure 1 As shown, the battery heating system 10 includes: a thermistor unit 1, a pure resistance heating unit 2, a first contactor 3, a second contactor 4, and a battery manager 6.

[0074] The thermistor unit 1 and the pure resistance heating unit 2 are used to heat the battery pack 5. The thermistor unit 1, the first contactor 3, and the battery pack 5 are connected in series in sequence. The pure resistance heating unit 2 is connected in series with the second contactor 4 and then connected in parallel with the first contactor 3. The battery manager 6 is connected to the first contactor 3 and the second contactor 4. The battery management system is used to execute the control method of the battery heating system in the above embodiment.

[0075] In this embodiment, when the first or second contactor has a fault such as sticking, the negative contactor 7 serves as a redundancy to improve the safety of the battery heating system.

[0076] It should be noted that the specific implementation of the battery heating system 10 in this embodiment of the invention is similar to the specific implementation of the control method of the battery heating system in any of the above embodiments of the invention. For details, please refer to the description of the method section. To reduce redundancy, it will not be repeated here.

[0077] According to the battery heating system 10 of the present invention, by executing the control method of the battery heating system of the above embodiment, the heating power of the battery heating system can be actively adjusted by the state parameters of the battery pack, which is beneficial to improve heating efficiency and shorten heating time.

[0078] A fourth aspect of the present invention provides a battery charging and discharging system 20, such as... Figure 3 As shown, it includes the battery heating system 10 in the above embodiments.

[0079] According to the battery charging and discharging system 20 of the present invention, the heating power of the battery heating system can be actively adjusted by the state parameters of the battery pack through the battery heating system described in the above embodiment, which helps to improve heating efficiency and shorten heating time.

[0080] A fifth aspect embodiment of the present invention provides a vehicle 30, such as Figure 4 As shown, it includes the battery charging and discharging system 20 in the above embodiments.

[0081] According to the vehicle 30 of the present invention, the heating power of the battery heating system can be actively adjusted by the state parameters of the battery pack, which helps to improve heating efficiency and shorten heating time.

[0082] In the description of this specification, any process or method described in the flowcharts or otherwise herein may be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order according to the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0083] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0084] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any of the following techniques known in the art, or a combination thereof: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0085] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0086] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0087] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0088] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0089] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A control method for a battery heating system, characterized in that, The battery heating system includes a thermistor unit and a pure resistance heating unit for heating the battery pack, as well as a first contactor and a second contactor. The thermistor unit, the first contactor, and the battery pack are connected in series. The pure resistance heating unit is connected in series with the second contactor and then in parallel with the first contactor. The control method includes: Obtain the state parameters of the battery pack; The switching states of the first contactor and the second contactor are controlled according to the state parameters of the battery pack; The method of controlling the switching states of the first contactor and the second contactor based on the state parameters of the battery pack includes: If the state parameters of the battery pack meet the charging or discharging heating conditions, control the second contactor to close so that the thermistor unit and the pure resistance heating unit can jointly heat the battery pack. The thermistor unit is used to heat the surface of the battery pack. After controlling the second contactor to close, it controls the switching states of the first and second contactors according to the state parameters of the battery pack. The system also includes: Once the state parameters of the battery pack are determined to meet the heating limit conditions, the first contactor is controlled to alternately close and open.

2. The control method for the battery heating system according to claim 1, characterized in that, The battery pack's state parameters include at least the remaining charge value, the minimum temperature value, and the maximum temperature value of the battery pack during charging and discharging. Determining that the battery pack's state parameters meet the charging / discharging heating conditions and controlling the second contactor to close includes: When the battery pack is in a discharging state, and it is determined that the remaining charge value is greater than a first preset charge value, the minimum temperature value is less than a first preset temperature, and the maximum temperature value is less than a second preset temperature, the second contactor is controlled to close, wherein the second preset temperature is greater than the first preset temperature.

3. The control method for the battery heating system according to claim 1, characterized in that, The state parameters of the battery pack include at least the minimum and maximum temperature values ​​of the battery pack during charging and discharging. Determining that the state parameters of the battery pack meet the charging / discharging heating conditions and controlling the second contactor to close includes: When the battery pack is in a charging state, and the minimum temperature value is determined to be less than a third preset temperature and the maximum temperature value is determined to be less than a fourth preset temperature, the second contactor is controlled to close, wherein the fourth preset temperature is greater than the third preset temperature.

4. The control method for the battery heating system according to claim 1, characterized in that, When the state parameters of the battery pack meet the heating limit conditions, the first contactor is alternately closed and opened, including: Calculate the temperature difference between the maximum temperature value and the minimum temperature value of the battery pack during the charging and discharging process; If the temperature difference is determined to be greater than a first preset temperature difference threshold, the first contactor is controlled to alternately close and open.

5. The control method for the battery heating system according to claim 1, characterized in that, Controlling the first contactor to alternately close and open includes: The calculation steps involve calculating the temperature difference between the maximum temperature value and the minimum temperature value of the battery pack during the charging and discharging process. The first determining step is to determine the target conduction duration based on the temperature difference. The closing procedure is controlled, and the duration for which the first contactor closes the target conduction is controlled; The second determination step involves determining the target disconnection duration based on the minimum temperature value. Control the disconnection step, and control the first contactor to disconnect the target disconnection duration; The calculation step, the first determination step, the control closing step, the second determination step, and the control opening step are executed repeatedly until the state parameters of the battery pack meet the heating exit condition, at which point both the first contactor and the second contactor are opened.

6. The control method for the battery heating system according to claim 5, characterized in that, Until the state parameters of the battery pack meet the heating exit condition, control both the first contactor and the second contactor to disconnect, including: If the minimum temperature value is determined to be greater than the fifth preset temperature, both the first contactor and the second contactor will be disconnected. Alternatively, if the maximum temperature value is determined to be greater than the sixth preset temperature, both the first contactor and the second contactor are controlled to disconnect. Alternatively, if the temperature difference is determined to be greater than a second preset temperature difference threshold, both the first contactor and the second contactor may be disconnected.

7. The control method for the battery heating system according to claim 6, characterized in that, When the battery pack is in a discharging state, the process of controlling both the first contactor and the second contactor to disconnect until the state parameters of the battery pack meet the heating exit condition also includes: If the remaining power of the battery pack is determined to be less than a second preset power value, both the first contactor and the second contactor are controlled to disconnect.

8. The control method for the battery heating system according to any one of claims 5-7, characterized in that, The temperature difference is proportional to the target conduction duration.

9. The control method for the battery heating system according to any one of claims 5-7, characterized in that, The minimum temperature value is inversely proportional to the duration of the target disconnection.

10. A computer storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the control method of the battery heating system according to any one of claims 1-9.

11. A battery heating system, characterized in that, include: Thermistor unit and pure resistance heating unit used for heating the battery pack; The first contactor and the second contactor, the thermistor unit, the first contactor and the battery pack are connected in series in sequence, and the pure resistance heating unit is connected in series with the second contactor and then connected in parallel with the first contactor; A battery manager, connected to the first contactor and the second contactor, is used to execute the control method of the battery heating system according to any one of claims 1-9.

12. A battery charging and discharging system, characterized in that, Includes the battery heating system as described in claim 11.

13. A vehicle, characterized in that, Includes the battery charging and discharging system as described in claim 12.

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