Battery temperature control device and battery management system

Abstract

The application relates to the battery technical field and discloses a battery temperature control device and a battery management system. The battery temperature control device comprises a switching module, a temperature acquisition module, a charging and discharging module, an internal resistance detection module and a control module; the switching module is connected with a plurality of battery monomers in series in a battery pack and has a plurality of conduction states; the temperature acquisition module is configured to acquire the temperature of the battery monomers; the charging and discharging module can discharge or charge the corresponding battery monomers when the switching module is in the corresponding conduction state; the internal resistance detection module can detect the internal resistance of the corresponding battery monomers when the switching module is in the corresponding conduction state; and the control module is configured to set the conduction state of the switching module according to the battery temperature parameter of the battery monomers and the internal resistance value, so that the charging and discharging module alternately charges and discharges the battery monomer with the maximum internal resistance value, and the battery monomer is subjected to pulse self-heating. The application can improve the battery equalization efficiency.

Description

TECHNICAL FIELD

[0001] The application relates to the battery technology field, in particular to a battery temperature control device and a battery management system. BACKGROUND

[0002] The vehicle-mounted power battery pack is usually composed of multiple battery monomers.

[0003] The battery monomer is usually a lithium ion battery. However, the lithium ion battery is prone to charging difficulty, discharge efficiency reduction and cycle life attenuation in a low-temperature environment.

[0004] In order to solve the above problems, the battery monomer can be effectively heated by a pulse heating method before the working cycle of the vehicle-mounted power battery pack. However, since the real-time temperature and aging degree of each battery monomer are inconsistent, the battery monomer cannot be heated in a targeted manner in the process of internally heating the battery monomer by using a pulse heating current, resulting in reduced heating efficiency. SUMMARY

[0005] The application aims to provide a battery temperature control device and a battery management system, which can control the temperature of a single battery monomer in a battery pack and improve the battery balancing efficiency.

[0006] The application provides a battery temperature control device, which comprises:

[0007] A switch module is connected to multiple battery monomers in series in a battery pack and has multiple conduction states.

[0008] A temperature acquisition module is configured to acquire the temperature of the battery monomer.

[0009] A charge-discharge module is connected to the switch module and can discharge or charge the corresponding battery monomer when the switch module is in the corresponding conduction state.

[0010] An internal resistance detection module is connected to the switch module and can detect the internal resistance of the corresponding battery monomer when the switch module is in the corresponding conduction state.

[0011] A control module is connected to the switch module, the temperature acquisition module, the charge-discharge module and the internal resistance detection module and is configured to set the conduction state of the switch module according to the battery temperature parameter and the internal resistance value of the battery monomer, so that the charge-discharge module alternately charges and discharges the battery monomer with the largest internal resistance value to pulse self-heat the battery monomer.

[0012] In some embodiments, the control module is further configured to set the on-off state of the switch module according to the battery temperature parameter of the battery cell with the maximum internal resistance value, so that the charging and discharging module performs alternating charging and discharging on the battery cell with the maximum internal resistance value.

[0013] The battery temperature parameter and the internal resistance value of each battery cell are obtained.

[0014] The average battery temperature parameter is calculated according to the battery temperature parameter of each battery cell.

[0015] It is determined whether the average battery temperature parameter reaches a temperature threshold parameter.

[0016] If not, the on-off state of the switch module is set, the battery cell with the maximum internal resistance value is formed into a loop with the charging and discharging module, the charging and discharging module performs alternating charging and discharging on the battery cell with the maximum internal resistance value, and the step of obtaining the battery temperature parameter and the internal resistance value of each battery cell is returned.

[0017] In some embodiments, the control module is further configured to make the charging and discharging module discharge the battery cell with the maximum internal resistance value at a first pulse heating frequency and charge the battery cell with the maximum internal resistance value at a second pulse heating frequency; the first pulse heating frequency and the second pulse heating frequency are positively correlated with the battery temperature parameter of the battery cell when the battery temperature parameter of the battery cell is in a first temperature interval, the first pulse heating frequency and the second pulse heating frequency are negatively correlated with the battery temperature parameter of the battery cell when the battery temperature parameter of the battery cell is in a second temperature interval, and the maximum critical value of the first temperature interval is not greater than the minimum critical value of the second temperature interval.

[0018] In some embodiments, the control module is further configured to set the on-off state of the switch module according to the deviation degree between the internal resistance value of the battery cell with the maximum internal resistance value and the internal resistance value of other battery cells, so that the charging and discharging module performs alternating charging and discharging on several battery cells including the battery cell with the maximum internal resistance value.

[0019] In some embodiments, the control module is further configured to set the on-off state of the switch module according to the battery temperature parameter of the battery cell, so that the charging and discharging module performs alternating charging and discharging on each battery cell to perform pulse self-heating on each battery cell.

[0020] In some embodiments, the control module is further configured to set the on-off state of the switch module according to the battery temperature parameter of the battery cell with the maximum internal resistance value, so that the charging and discharging module performs alternating charging and discharging on the battery cell with the maximum internal resistance value.

[0021] acquire a battery temperature parameter of each of the battery cells;

[0022] calculate an average battery temperature parameter according to the battery temperature parameters of each of the battery cells;

[0023] determine whether the average battery temperature parameter reaches a temperature threshold parameter;

[0024] if not, set the on state of the switch module and form a loop between each of the battery cells and the charge-discharge module, so that the charge-discharge module alternately charges and discharges each of the battery cells, and return to the step of acquiring the battery temperature parameter and the internal resistance value of each of the battery cells.

[0025] In some embodiments, the switch module includes a plurality of first branches and a plurality of second branches;

[0026] The first end of the battery cell is connected to the first end of one of the first branches and the first end of one of the second branches, respectively, and the second end of the battery cell is connected to the first end of another of the first branches and the first end of another of the second branches, respectively. The second end of the first branch is connected to the first end of the charge-discharge module, and the second end of the second branch is connected to the second end of the charge-discharge module.

[0027] The control module is connected to the first branch and the second branch, and is configured to turn on or turn off the first branch and the second branch to form a loop between the corresponding battery cell and the charge-discharge module.

[0028] In some embodiments, the charge-discharge module includes a first inductor, a first capacitor, a diode, and a first switch;

[0029] The first inductor, the first capacitor, and the first switch are connected in series and form a loop with the corresponding battery cell when the first switch is closed and the switch module is in the corresponding on state;

[0030] The cathode of the diode is connected to one end of the first capacitor close to the first inductor, and the anode of the diode is connected to one end of the first capacitor away from the first inductor;

[0031] The control module is connected to the first switch and is configured to set the on state of the first switch and set the current direction of the loop formed by the battery cell, the switch module, and the charge-discharge module.

[0032] In some embodiments, the internal resistance detection module includes a second inductor, a second capacitor, a second switch, a third switch, and a resistor;

[0033] The resistor, the second inductor, the second capacitor and the second switch are connected in series to form a loop with the corresponding battery monomer when the second switch is closed and the switch module is in a corresponding conduction state;

[0034] The third switch is connected in parallel with the resistor, the second inductor and the second capacitor.

[0035] The control module is connected with the second switch and the third switch, and is configured to set the conduction state of the second switch and the conduction state of the third switch, so that the resistor, the second inductor and the second capacitor form a loop with the corresponding battery monomer.

[0036] The application further provides a battery management system comprising the above battery temperature control device.

[0037] The application has the following beneficial effects: The switch module, the temperature acquisition module, the charging and discharging module, the internal resistance detection module and the control module are configured, the battery temperature parameters and the internal resistance values of the battery monomers can be acquired in real time, the control module sets the conduction state of the switch module according to the battery temperature parameters and the internal resistance values of the battery monomers, the charging and discharging module alternately charges and discharges the battery monomer with the largest internal resistance value, the battery monomer is self-heated by pulse, the battery monomer to be controlled in temperature can be flexibly configured according to the battery temperature parameters and the internal resistance values of the battery monomers, the battery monomer with the largest internal resistance value is self-heated by pulse, and the battery temperature control efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a structural schematic diagram of a battery temperature control device provided by a first embodiment of the application.

[0039] Figure 2 is a structural schematic diagram of a battery temperature control device provided by a second embodiment of the application.

[0040] Figure 3 is a temperature control schematic diagram of a battery temperature control device provided by the first embodiment of the application.

[0041] Figure 4 is a temperature control schematic diagram of a battery temperature control device provided by the second embodiment of the application.

[0042] Figure 5 is a temperature control schematic diagram of a battery temperature control device provided by a third embodiment of the application.

[0043] Figure 6 is a temperature control schematic diagram of a battery temperature control device provided by a fourth embodiment of the application. DETAILED DESCRIPTION

[0044] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0045] It should be noted that although the functional modules are divided in the device schematic diagram, and the logical sequence is shown in the flowchart, in some cases, the steps shown can be performed in a manner different from the module division in the device or the sequence in the flowchart. The terms "first", "second", etc. in the specification and claims and drawings are used to distinguish similar objects, and are not intended to describe a specific order or sequence.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application.

[0047] The embodiments of the present application provide a battery temperature control device. Referring to Figure 1 In some embodiments, the battery temperature control device includes a switching module 100, a temperature acquisition module 200, a charging and discharging module 300, an internal resistance detection module 400 and a control module 500.

[0048] The switching module 100 is connected to a plurality of battery monomers in series in a battery pack, and the switching module 100 has a plurality of conduction states. Specifically, the switching module 100 is connected to a plurality of battery monomers in the battery pack, and by being configured as different conduction states, one or more battery monomers can be connected to an external circuit through the switching module 100. For example, when the switching module 100 is set to a first conduction state, the first battery monomer can be connected to the external circuit while the other battery monomers are not connected to the external circuit, when the switching module 100 is set to a second conduction state, the second battery monomer can be connected to the external circuit while the other battery monomers are not connected to the external circuit, and when the switching module 100 is set to an n-th conduction state, all battery monomers can be connected to the external circuit.

[0049] The temperature acquisition module 200 is configured to acquire the temperature of the battery monomers. Specifically, the temperature acquisition module 200 has a plurality of temperature acquisition modules, each of which is arranged near each battery monomer, and by acquiring the temperature of each battery monomer, the battery temperature parameters of each battery monomer are obtained.

[0050] The charging and discharging module 300 is connected to the switch module 100. The charging and discharging module 300 can discharge or charge the corresponding battery cell when the switch module 100 is in the corresponding conduction state. Specifically, the charging and discharging module 300 has two charging and discharging states, i.e., external discharging and external charging. When the switch module 100 is in the corresponding conduction state, the charging and discharging module 300 is connected to the corresponding battery cell. The charging and discharging module 300 in the external discharging state discharges the corresponding battery cell and stores the electrical energy released by the battery cell. The charging and discharging module 300 in the external charging state charges the corresponding battery cell using the pre-stored electrical energy.

[0051] The internal resistance detection module 400 is connected to the switch module 100. The internal resistance detection module 400 can detect the internal resistance of the corresponding battery cell when the switch module 100 is in the corresponding conduction state. Specifically, the internal resistance detection module 400 calculates the internal resistance of the battery cell based on Ohm's law by measuring the voltage and current response of the battery cell under alternating current (AC) or direct current (DC) conditions.

[0052] The control module 500 is connected to the switch module 100, the temperature acquisition module 200, the charging and discharging module 300, and the internal resistance detection module 400. The control module 500 is configured to set the conduction state of the switch module 100 according to the battery temperature parameter of the battery cell and the internal resistance, so that the charging and discharging module 300 alternately charges and discharges the battery cell with the largest internal resistance to pulse self-heat the battery cell. Specifically, the control module 500 sets the conduction state of the switch module 100 according to the battery temperature parameter of the battery cell and the internal resistance. When the battery temperature parameter of the battery cell does not reach the preset temperature threshold parameter, the control module 500 determines the battery cell with the largest internal resistance and sets the conduction state of the switch module 100, so that the charging and discharging module 300 alternately charges and discharges the battery cell with the largest internal resistance. The charging and discharging module 300 first discharges the battery cell with the largest internal resistance and stores the electrical energy released by the battery cell, and then charges the battery cell with the largest internal resistance using the stored electrical energy. In this way, by alternately charging and discharging the battery cell with the largest internal resistance multiple times, heat energy is generated through the internal resistance of the battery cell, which can increase the temperature inside the battery cell with the largest internal resistance and generate heat energy.

[0053] In some embodiments, the switch module 100 is set to the on state according to the battery temperature parameters and the internal resistance values of the battery cells, and the alternating charging and discharging of the battery cell with the largest internal resistance value by the charging and discharging module 300 includes: obtaining the battery temperature parameters and the internal resistance values of the battery cells; calculating an average battery temperature parameter according to the battery temperature parameters of the battery cells; determining whether the average battery temperature parameter reaches a temperature threshold parameter; if not, setting the on state of the switch module 100 and forming a loop between the battery cell with the largest internal resistance value and the charging and discharging module 300, so that the charging and discharging module 300 alternately charges and discharges the battery cell with the largest internal resistance value, and returning to the step of obtaining the battery temperature parameters and the internal resistance values of the battery cells.

[0054] It can be understood that before the average battery temperature parameter reaches the temperature threshold parameter, the control module 500 periodically alternately charges and discharges the battery cell with the largest current internal resistance value until the average battery temperature parameter reaches the temperature threshold parameter. Thus, the battery cell with the largest internal resistance value in the battery pack can be heated specifically, and the battery temperature parameters of the battery cells with the lowest temperature and / or the most serious aging in the battery pack tend to be close to the battery temperature parameters of other battery cells in the battery pack. Specifically, in the current heating period, the temperature collection module 200 collects the temperature of each battery cell and obtains the battery temperature parameters of each battery cell, the internal resistance detection module 400 detects the internal resistance of each battery cell and obtains the internal resistance values of each battery cell, the control module 500 obtains the battery temperature parameters and the internal resistance values of each battery cell through the temperature collection module 200 and the internal resistance detection module 400, calculates the average battery temperature parameter by averaging the battery temperature parameters of each battery cell, compares the average battery temperature parameter with the temperature threshold parameter, if the average battery temperature parameter reaches the temperature threshold parameter, the current heating period ends and the next heating period begins, if the average battery temperature parameter does not reach the temperature threshold parameter, the on state of the switch module 100 is set to form a loop between the battery cell with the largest internal resistance value and the charging and discharging module 300, and the current of the loop formed by the battery cell with the largest internal resistance value and the charging and discharging module 300 is controlled, so that the charging and discharging module 300 alternately charges and discharges the battery cell with the largest internal resistance value within a preset charging and discharging time, and enters the next heating period when the preset charging and discharging time ends.

[0055] In some embodiments, the control module 500 is further configured to cause the charge-discharge module 300 to discharge the battery cell with the largest internal resistance at a first pulse heating frequency and charge the battery cell with the largest internal resistance at a second pulse heating frequency. Wherein the first pulse heating frequency and the second pulse heating frequency are positively correlated with the battery temperature parameter of the battery cell when the battery temperature parameter of the battery cell is in a first temperature interval, and the first pulse heating frequency and the second pulse heating frequency are negatively correlated with the battery temperature parameter of the battery cell when the battery temperature parameter of the battery cell is in a second temperature interval, and the maximum critical value of the first temperature interval is not greater than the minimum critical value of the second temperature interval.

[0056] It can be understood that charging or discharging the battery cell at a temperature that is too low can cause low charging efficiency and reduce the service life of the battery, and the lower the temperature, the more obvious the above problems. Therefore, the first pulse heating frequency and the second pulse heating frequency are positively correlated with the battery temperature parameter of the battery cell in a relatively lower low-temperature environment, the charging intensity and the discharging intensity are reduced, the battery cell is slowly heated to a relatively higher low-temperature environment, which can reduce the damage to the battery cell caused by charging and discharging in a low-temperature environment, and the first pulse heating frequency and the second pulse heating frequency are positively correlated with the battery temperature parameter of the battery cell in a relatively higher low-temperature environment, the charging intensity and the discharging intensity are increased, the battery cell is quickly heated to a target temperature, which can improve the heating speed of the battery cell. Specifically, a first temperature interval and a second temperature interval are preset, the temperature parameter in the first temperature interval represents a relatively lower low-temperature environment, and the temperature parameter in the second temperature interval represents a relatively higher low-temperature environment. It is determined whether the battery cell with the largest internal resistance is in the first temperature interval or the second temperature interval. If it is in the first temperature interval, the corresponding first pulse heating frequency and the second pulse heating frequency are determined according to the battery cell with the largest internal resistance, so that the first pulse heating frequency and the second pulse heating frequency are positively correlated with the battery temperature parameter of the battery cell. If it is in the second temperature interval, the corresponding first pulse heating frequency and the second pulse heating frequency are determined according to the battery cell with the largest internal resistance, so that the first pulse heating frequency and the second pulse heating frequency are negatively correlated with the battery temperature parameter of the battery cell. Then, the charge-discharge module 300 discharges the battery cell with the largest internal resistance at the first pulse heating frequency and charges the battery cell with the largest internal resistance at the second pulse heating frequency, and the battery cell with the largest internal resistance is alternately charged and discharged.

[0057] In some embodiments, the control module 500 is further configured to set the on-off state of the switch module 100 according to the deviation between the internal resistance of the battery cell with the largest internal resistance and the internal resistance of other battery cells, so that the charge-discharge module 300 alternately charges and discharges several battery cells including the battery cell with the largest internal resistance.

[0058] It can be understood that, according to the deviation degree between the internal resistance value of the battery cell with the largest internal resistance value and the internal resistance values of the other battery cells, the battery cell with the deviation between the internal resistance value and the internal resistance value of the battery cell with the largest internal resistance value within the preset deviation interval is selected from the other battery cells, and then the battery cell with the largest internal resistance value and the selected battery cell are alternately charged and discharged, which can further improve the balancing efficiency of the battery cells. Specifically, before the battery cell with the largest internal resistance value is alternately charged and discharged, the control module 500 first determines the deviation degree between the internal resistance value of the battery cell with the largest internal resistance value and the internal resistance values of the other battery cells, compares the internal resistance deviation value between the internal resistance value of the battery cell with the largest internal resistance value and the internal resistance values of the other battery cells with the preset deviation value, to determine whether the internal resistance deviation value between the internal resistance value of the battery cell with the largest internal resistance value and the internal resistance values of the other battery cells is within the preset deviation interval, and if so, the battery cell is selected. By setting the conduction state of the switch module 100, the charge-discharge module 300 alternately charges and discharges the battery cell with the largest internal resistance value and the selected battery cell.

[0059] In some embodiments, the control module 500 is also configured to set the conduction state of the switch module 100 according to the battery temperature parameter of the battery cell, so that the charge-discharge module 300 alternately charges and discharges each battery cell to pulse self-heat each battery cell.

[0060] Specifically, the control module 500 sets the conduction state of the switch module 100 according to the battery temperature parameter of the battery cell, and when the battery temperature parameter of the battery cell does not reach the preset temperature threshold parameter, the control module 500 sets the conduction state of the switch module 100, so that the charge-discharge module 300 alternately charges and discharges each battery cell. The charge-discharge module 300 first discharges the electrical energy released by the storage battery cell, and then uses the stored electrical energy to charge each battery cell. In this way, by alternately charging and discharging each battery cell multiple times, heat energy can be generated through the internal resistance of the battery cell, so that the temperature inside each battery cell can be increased to generate heat energy.

[0061] In some embodiments, the setting the on state of the switch module 100 according to the battery temperature parameter of the battery cell, and causing the charge-discharge module 300 to perform the alternating charge-discharge on the battery cells comprises: obtaining the battery temperature parameter of each battery cell; calculating an average battery temperature parameter according to the battery temperature parameter of each battery cell; determining whether the average battery temperature parameter reaches a temperature threshold parameter; if not, setting the on state of the switch module 100 and causing each battery cell to form a loop with the charge-discharge module 300, causing the charge-discharge module 300 to perform the alternating charge-discharge on the battery cells, and returning to the step of obtaining the battery temperature parameter and the internal resistance value of each battery cell.

[0062] It can be understood that the control module 500 periodically performs the alternating charge-discharge on the battery cells until the average battery temperature parameter reaches the temperature threshold parameter. Thus, all the battery cells in the battery pack can be heated at the same time, and the battery temperature parameter of all the battery cells in the battery pack tends to be close to the temperature threshold parameter. Specifically, in the current heating period, the temperature collection module 200 collects the temperature of each battery cell and obtains the battery temperature parameter of each battery cell, the control module 500 obtains the battery temperature parameter of each battery cell through the temperature collection module 200, calculates the average battery temperature parameter by averaging the battery temperature parameter of each battery cell, compares the average battery temperature parameter with the temperature threshold parameter, if the average battery temperature parameter reaches the temperature threshold parameter, the current heating period ends and the next heating period begins, if the average battery temperature parameter does not reach the temperature threshold parameter, the on state of the switch module 100 is set to cause each battery cell to form a loop with the charge-discharge module 300, and the current direction of the current in the loop formed by each battery cell and the charge-discharge module 300 is controlled, so that the charge-discharge module 300 performs the alternating charge-discharge on the battery cells within a preset charge-discharge time, and enters the next heating period when the preset charge-discharge time ends.

[0063] The battery temperature control device provided by the present application will be described below in combination with specific embodiments.

[0064] For reference Figure 1 and Figure 2In one specific embodiment, the switch module 100 includes a plurality of first branches 110 and a plurality of second branches 120, the first end of the battery cell is connected to the first end of one of the first branches 110 and the first end of one of the second branches 120, the second end of the battery cell is connected to the first end of another of the first branches 110 and the first end of another of the second branches 120, the second end of the first branch 110 is connected to the first end of the charge-discharge module 300, and the second end of the second branch 120 is connected to the second end of the charge-discharge module 300. The control module 500 is connected to the first branch 110 and the second branch 120, and the control module 500 is configured to turn on or turn off the first branch 110 and the second branch 120 to form a loop between the corresponding battery cell and the charge-discharge module 300. More specifically, the first branch 110 and the second branch 120 are both obtained by connecting two field effect tubes in series in a back-to-back manner, the control module 500 is connected to the gate of the field effect tube, and the control module 500 can set the current direction of the loop formed by the battery cell, the switch module 100 and the charge-discharge module 300 by setting the conduction state of the field effect tube.

[0065] For reference Figure 1 and Figure 2 In one specific embodiment, the charge-discharge module 300 includes a first inductor L1, a first capacitor C1, a diode D1 and a first switch K1, the first inductor L1, the first capacitor C1 and the first switch K1 are connected in series, and form a loop with the corresponding battery cell when the first switch K1 is closed and the switch module 100 is in a corresponding conduction state, the cathode of the diode D1 is connected to one end of the first capacitor C1 close to the first inductor L1, and the anode of the diode D1 is connected to one end of the first capacitor C1 away from the first inductor L1. The control module 500 is connected to the first switch K1, and the control module 500 is configured to set the conduction state of the first switch K1 and set the current direction of the loop formed by the battery cell, the switch module 100 and the charge-discharge module 300.

[0066] For reference Figure 1 and Figure 2 In one specific embodiment, the internal resistance detection module 400 includes a second inductor L2, a second capacitor C2, a second switch K2, a third switch K3 and a resistor R LC , the resistor R LC , the second inductor L2, the second capacitor C2 and the second switch K2 are connected in series, and form a loop with the corresponding battery cell when the second switch K2 is closed and the switch module 100 is in a corresponding conduction state, the third switch K3 is connected across the resistor R LC , the second inductor L2 and the second capacitor C2. The control module 500 is connected to the second switch K2 and the third switch K3, and the control module 500 is configured to set the conduction state of the second switch K2 and the conduction state of the third switch K3 to make the resistor RLC , the second inductor L2, the second capacitor C2 and the corresponding battery cell form a loop.

[0067] With reference to Figure 1 , Figure 3 and Figure 4 , in a specific embodiment, the control module 500 sets the on-off state of the switch module 100 and makes the second switch K2 closed and the third switch K3 open, so that the second inductor L2, the second capacitor C2 and the resistor R LC of the internal resistance detection module 400 form a loop with the corresponding battery cell and measure the internal resistance value of the battery cell. When the battery temperature parameter of the battery cell does not reach the preset temperature threshold parameter and the internal resistance value of the second battery cell in the battery pack is the largest, the control module 500 sets the on-off state of the switch module 100 to make the charge-discharge module 300 alternately charge and discharge the second battery cell in the battery pack. When discharging, the control module 500 makes the first branch 110 (Q3, M3) and the second branch 120 (Q4, M4) open and makes the first switch K1 of the charge-discharge module 300 closed, so that the second battery cell in the battery pack forms a loop with the first inductor L1 in the charge-discharge module 300. The first inductor L1 discharges the second battery cell in the battery pack and stores the electrical energy released by the second battery cell in the battery pack. When charging, the control module 500 makes the first branch 110 (Q5) and the second branch 120 (Q2) open and makes the first switch K1 of the charge-discharge module 300 closed, so that the second battery cell in the battery pack forms a loop with the first inductor L1 in the charge-discharge module 300. The first inductor L1 charges the second battery cell in the battery pack using the stored electrical energy.

[0068] With reference to Figure 1 , Figure 5 and Figure 6 , in a specific embodiment, when the battery temperature parameter of the battery cell does not reach the preset temperature threshold parameter, the control module 500 sets the on-off state of the switch module 100 to make the charge-discharge module 300 alternately charge and discharge all battery cells in the battery pack. When discharging, the control module 500 makes the first branch 110 (Q 2n+1 ) and the second branch 120 (Q0) open and makes the first switch K1 of the charge-discharge module 300 closed, so that all battery cells in the battery pack form a loop with the first inductor L1 and the first capacitor C1 in the charge-discharge module 300. The first inductor L1 and the first capacitor C1 discharge all battery cells in the battery pack and store the electrical energy released by all battery cells in the battery pack. When charging, the control module 500 makes the first branch 110 (Q 2n+1) and the second branch 120 (Q0) is opened, and the first switch K1 of the charge-discharge module 300 is closed, so that all the battery monomers in the battery pack form a loop with the first inductor L1 and the first capacitor C1 in the charge-discharge module 300, and all the battery monomers in the battery pack are charged by the first inductor L1 and the first capacitor C1 using the stored electric energy.

[0069] The application further provides a battery management system. The battery management system comprises the battery temperature control device described above, and the specific structure of the battery temperature control device is referred to the above embodiments. Since the battery management system provided by the application adopts all the technical solutions of the above embodiments, it has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0070] In summary, the battery temperature control device and the battery management system provided by the application are configured with a switching module, a temperature acquisition module, a charge-discharge module, an internal resistance detection module and a control module, which can acquire the battery temperature parameters and the internal resistance values of each battery monomer in real time, set the conduction state of the switching module according to the battery temperature parameters and the internal resistance values of the battery monomer through the control module, and make the charge-discharge module alternately charge and discharge the battery monomer with the largest internal resistance value to pulse self-heat the battery monomer. Therefore, the battery monomer to be temperature controlled can be flexibly configured according to the battery temperature parameters and the internal resistance values of the battery monomer, the battery monomer with the largest internal resistance value is pulse self-heated, and the battery temperature control efficiency is improved.

[0071] It should be understood that, in the present application, "at least one" means one or more, and "multiple" means two or more. "And / or" is used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, "A and / or B" can mean that there are three cases of only A, only B and A and B at the same time, wherein A and B can be singular or plural. The character " / " generally represents an "or" relationship between the front and rear associated objects. "At least one of the following" or the like means any combination of these items, including single item or any combination of multiple items. For example, at least one of a, b or c can mean a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b and c can be single or multiple.

[0072] The preferred embodiments of the application are described above with reference to the accompanying drawings, which do not limit the scope of the application. Any modifications, equivalent replacements and improvements made by those skilled in the art without departing from the scope and essence of the application shall be within the scope of the application.

Claims

1. A battery temperature control device, characterized in that, include: The switch module connects multiple battery cells connected in series in the battery pack and has multiple conduction states; The temperature acquisition module is configured to acquire the temperature of the battery cell; The charging / discharging module is connected to the switching module and can discharge or charge the corresponding battery cell when the switching module is in the corresponding on state. An internal resistance detection module, connected to the switch module, can detect the internal resistance of the corresponding battery cell when the switch module is in the corresponding on state. The control module, connected to the switch module, the temperature acquisition module, the charge / discharge module, and the internal resistance detection module, is configured to set the conduction state of the switch module based on the battery temperature parameters and internal resistance value of the battery cell, so that the charge / discharge module alternately charges and discharges the battery cell with the largest internal resistance value to perform pulse self-heating on the battery cell.

2. The battery temperature control device according to claim 1, characterized in that, The step of setting the conduction state of the switch module based on the battery temperature parameters and internal resistance value of the individual battery cells, so that the charge / discharge module alternately charges and discharges the battery cell with the largest internal resistance value, includes: Obtain the battery temperature parameters and internal resistance values ​​of each of the battery cells; Calculate the average battery temperature parameter based on the battery temperature parameters of each individual battery cell; Determine whether the average battery temperature parameter has reached the temperature threshold parameter; If the condition is not met, the switch module is set to conduction state, and the battery cell with the largest internal resistance value is made to form a circuit with the charging and discharging module. The charging and discharging module then alternately charges and discharges the battery cell with the largest internal resistance value, and the process returns to the step of obtaining the battery temperature parameters and internal resistance values ​​of each battery cell.

3. The battery temperature control device according to claim 1, characterized in that, The control module is further configured to cause the charging / discharging module to discharge the battery cell with the largest internal resistance at a first pulse heating frequency and to charge the battery cell with the largest internal resistance at a second pulse heating frequency; the first pulse heating frequency and the second pulse heating frequency are positively correlated with the battery temperature parameter of the battery cell when the battery temperature parameter of the battery cell is in a first temperature range, and negatively correlated with the battery temperature parameter of the battery cell when the battery temperature parameter of the battery cell is in a second temperature range, wherein the maximum critical value of the first temperature range is not greater than the minimum critical value of the second temperature range.

4. The battery temperature control device according to claim 1, characterized in that, The control module is further configured to set the conduction state of the switch module based on the degree of deviation between the internal resistance value of the battery cell with the largest internal resistance value and the internal resistance values ​​of other battery cells, so that the charging and discharging module alternately charges and discharges several battery cells, including the battery cell with the largest internal resistance value.

5. The battery temperature control device according to claim 1, characterized in that, The control module is also configured to set the conduction state of the switch module according to the battery temperature parameters of the battery cells, so that the charge and discharge module alternately charges and discharges each of the battery cells to perform pulse self-heating on each of the battery cells.

6. The battery temperature control device according to claim 5, characterized in that, The step of setting the conduction state of the switching module based on the battery temperature parameters of the individual battery cells, so that the charging and discharging module alternately charges and discharges each of the individual battery cells, includes: Obtain the battery temperature parameters of each of the battery cells; Calculate the average battery temperature parameter based on the battery temperature parameters of each individual battery cell; Determine whether the average battery temperature parameter has reached the temperature threshold parameter; If the desired result is not achieved, the switch module is set to conduction state and each battery cell forms a circuit with the charge / discharge module, so that the charge / discharge module alternately charges and discharges each battery cell, and the process returns to the step of obtaining the battery temperature parameters and internal resistance values ​​of each battery cell.

7. The battery temperature control device according to any one of claims 1 to 6, characterized in that, The switch module includes multiple sets of first branches and multiple sets of second branches; The first end of the battery cell is connected to the first end of one of its first branches and the first end of one of its second branches, respectively. The second end of the battery cell is connected to the first end of another first branch and the first end of another second branch, respectively. The second end of the first branch is connected to the first end of the charging and discharging module, and the second end of the second branch is connected to the second end of the charging and discharging module. The control module, connected to the first branch and the second branch, is configured to turn the first branch and the second branch on or off, so that the corresponding battery cell forms a circuit with the charging and discharging module.

8. The battery temperature control device according to any one of claims 1 to 6, characterized in that, The charge / discharge module includes a first inductor, a first capacitor, a diode, and a first switch; The first inductor, the first capacitor, and the first switch are connected in series, and when the first switch is closed and the switch module is in the corresponding on state, a circuit is formed with the corresponding battery cell. The cathode of the diode is connected to the end of the first capacitor closest to the first inductor, and the anode of the diode is connected to the end of the first capacitor furthest from the first inductor. The control module, connected to the first switch, is configured to set the conduction state of the first switch and the current direction of the circuit formed by the battery cell, the switch module, and the charge / discharge module.

9. The battery temperature control device according to any one of claims 1 to 6, characterized in that, The internal resistance detection module includes a second inductor, a second capacitor, a second switch, a third switch, and a resistor; The resistor, the second inductor, the second capacitor, and the second switch are connected in series, and when the second switch is closed and the switch module is in the corresponding on state, a circuit is formed with the corresponding battery cell. The third switch is connected across the resistor, the second inductor, and the second capacitor; The control module, connected to the second switch and the third switch, is configured to set the conduction state of the second switch and the conduction state of the third switch, so that the resistor, the second inductor, the second capacitor and the corresponding battery cell form a circuit.

10. A battery management system, characterized in that, Includes the battery temperature control device as described in any one of claims 1 to 9.

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