Cell electric quantity active equalization device, battery management system and battery pack

Abstract

The utility model relates to the technical field of power batteries, and provides a battery cell electric quantity active equalization device, a battery management system and a battery pack, the battery cell electric quantity active equalization device comprises a discharge control module, a recharge control module and a capacitor, the discharge control module comprises a first connecting end and an input end, the first connecting end is electrically connected with a battery cell, and the input end is electrically connected with the capacitor. And the discharge control module is used for enabling the battery core to discharge outwards and limiting current backflow. According to the battery cell electric quantity active equalization device, the battery management system and the battery pack, the electric control module, the recharge control module and the capacitor are arranged, so that the capacitor is charged by the high-voltage battery cell, and the voltage of the high-voltage battery cell reaches an equalization value; if the voltage of the battery cell is low, the low-voltage battery cell is charged by the electric energy stored by the capacitor, so that the voltage of the low-voltage battery cell reaches an equilibrium value, and the voltage equilibrium control of the multiple battery cells is completed by a simple circuit.

Description

Technical Field

[0001] The utility model relates to the technical field of power batteries, and in particular to an active cell power equalization device, a battery management system and a battery pack. Background Art

[0002] BM is the abbreviation of Battery Management System, which is used to monitor and manage the performance of the battery pack to ensure the safe, efficient and long-life operation of the battery pack. BMS plays a key role in electric vehicles, energy storage systems and various portable electronic devices.

[0003] In the current new energy field, the existing problems of BMS (battery management system) are more prominent, such as balancing function, SOC accuracy, thermal management function, etc. Among them, the balancing function can be divided into active balancing and passive balancing in theory, also called dissipative balancing and non-dissipative balancing. For example, a passive balancing control method between battery cells with announcement number CN116073492B determines the constant voltage trickle charging time through the battery cell voltage difference, so as to perform more efficient balanced charging of each battery cell.

[0004] However, in the prior art, some passive balancing methods dissipate excess power in battery cells through resistor discharge to achieve the purpose of balancing. This method will waste the energy in the battery in the form of heat, reducing the energy efficiency of the entire system. For some active balancing methods, high-voltage batteries directly charge low-voltage batteries. The process of directly charging the battery requires a more complex circuit control and monitoring system to ensure that the charging state of each battery cell is balanced and safe, which increases the control complexity and design difficulty of the system. Utility Model Content

[0005] In view of this, the utility model proposes an active cell charge balancing device, a battery management system and a battery pack. By setting an electric control module, a recharge control module and a capacitor, a high-voltage cell can charge the capacitor, so that the voltage of the higher-voltage cell reaches a balanced value. When a low-voltage cell exists, the electric energy stored in the capacitor is used to charge the low-voltage cell, so that the voltage of the lower-voltage cell reaches a balanced value, thereby completing the voltage balancing control of multiple cells with a relatively simple circuit.

[0006] The technical solution of the utility model is achieved in this way:

[0007] On the one hand, the utility model provides a battery cell active equalization device, including a discharge control module, a recharge control module and a capacitor, wherein:

[0008] The discharge control module includes a first connection end and an input end, the first connection end is electrically connected to the battery cell, and the discharge control module is used to discharge the battery cell outward and limit current backflow;

[0009] The recharge control module includes a second connection terminal and an output terminal, the second connection terminal is electrically connected to the battery cell, and the recharge control module is used to enable the current to charge the battery cell and limit the current backflow;

[0010] One end of the capacitor is grounded, and the other end is electrically connected to the first connection end and the second connection end. The single battery cell is electrically connected to the capacitor only through the discharge control module and one of the recharge control modules.

[0011] On the basis of the above technical solution, preferably, the discharge control module includes a first switch and a first diode, wherein:

[0012] The first switch is arranged on the connection line between the battery cell and the capacitor, and the first switch is used to control the on and off of the battery cell and the capacitor;

[0013] The first diode is arranged on the connection line between the battery cell and the capacitor, so that when the first switch is closed, the battery cell can only charge the capacitor.

[0014] On the basis of the above technical solution, preferably, the recharge control module includes a second switch and a second diode, wherein:

[0015] The second switch is arranged on the connection line between the battery cell and the capacitor, and the second switch is used to control the connection and disconnection between the battery cell and the capacitor;

[0016] The second diode is arranged on the connection line between the battery cell and the capacitor, so that when the second switch is closed, the capacitor can only charge the battery cell.

[0017] On the basis of the above technical solution, preferably, it also includes an electricity module, and the electricity module is electrically connected to the capacitor to store electrical energy through the capacitor to perform operations.

[0018] Further preferably, the power module includes a heating element, and the heating element is electrically connected to the capacitor to convert the electrical energy stored in the capacitor into heat energy for release.

[0019] More preferably, the power module further includes a transistor, the emitter of the transistor is electrically connected to the capacitor, the collector of the transistor is electrically connected to the heating element, and the base of the transistor is externally connected to a power supply.

[0020] Further preferably, it also includes a control switch, which is arranged in the external wiring circuit of the capacitor and is electrically connected to the power consumption module and the recharging control module, and the control switch is used to electrically connect one of the power consumption module and the recharging control module to the capacitor.

[0021] On the other hand, the utility model provides a battery management system, including the above-mentioned battery cell active power equalization device.

[0022] On the basis of the above technical solution, preferably, a main control module is further included, and the main control module, the discharge control module and the recharge control module are used to control one of the discharge control module and the recharge control module to form a path between the capacitor and the battery cell.

[0023] On the other hand, the utility model provides a battery pack, including the above-mentioned battery management system.

[0024] Compared with the prior art, the battery cell active equalization device, battery management system and battery pack of the utility model have the following beneficial effects:

[0025] (1) By setting up an electric control module, a recharge control module and a capacitor, the high-voltage battery cell can charge the capacitor, so that the voltage of the higher-voltage battery cell reaches a balanced value. When there is a low-voltage battery cell, the electric energy stored in the capacitor is used to charge the low-voltage battery cell, so that the voltage of the lower-voltage battery cell reaches a balanced value, thereby completing the voltage balancing control of multiple battery cells with a relatively simple circuit;

[0026] (2) A power module can be set up to directly power the heating element in the power module through a capacitor. In a low-temperature environment, the working environment temperature of the battery pack can be increased to ensure that the battery cells can work normally and extend their service life. In addition, powering the battery pack through a capacitor can reduce the burden on the battery pack, and its rapid charging and discharging can provide higher instantaneous power than batteries. This efficient energy transfer can reduce energy loss and improve the efficiency of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 It is a structural schematic diagram of the battery cell active equalization device and the battery management system of the utility model. DETAILED DESCRIPTION

[0029] The following will be combined with the implementation of the utility model to clearly and completely describe the technical solutions in the implementation of the utility model. Obviously, the described implementation is only a part of the implementation of the utility model, not all of the implementations. Based on the implementation of the utility model, all other implementations obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0030] like Figure 1 As shown, the battery cell active equalization device of the present invention includes a discharge control module 1, a recharge control module 2 and a capacitor 3.

[0031] The discharge control module 1 includes a first connection end and an input end, wherein the first connection end is electrically connected to the battery cell. The discharge control module 1 is used to discharge the battery cell outward and limit current backflow.

[0032] Specifically, the discharge control module 1 includes a first switch 11 and a first diode 12. The first switch 11 is arranged on the connection line between the battery cell and the capacitor 3. The first switch 11 is used to control the on and off of the battery cell and the capacitor 3. The first diode 12 is arranged on the connection line between the battery cell and the capacitor 3 so that when the first switch 11 is closed, the battery cell can only charge the capacitor 3.

[0033] In a battery pack, battery cells are usually connected in series to supply power at a higher voltage, and the discharge control module 1 is arranged on the connecting piece between two adjacent battery cells. In the present embodiment, the number of the discharge control modules 1 is multiple, preferably not less than the number of battery cells, and is correspondingly arranged on each battery cell to achieve control when the voltage of a single battery cell is larger.

[0034] The recharge control module 2 includes a second connection end and an output end, the second connection end is electrically connected to the battery cell, and the recharge control module 2 is used to allow the current to charge the battery cell and limit the current backflow.

[0035] Specifically, the recharging control module 2 includes a second switch 21 and a second diode 22. The second switch 21 is arranged on the connection line between the battery cell and the capacitor 3. The second switch 21 is used to control the on and off of the battery cell and the capacitor 3. The second diode 22 is arranged on the connection line between the battery cell and the capacitor 3 so that when the second switch 21 is closed, the capacitor 3 can only charge the battery cell.

[0036] The basic structure of the recharge control module 2 is the same as that of the discharge control module 1, except that the first diode 12 and the second diode 22 are connected. One end of the first diode 12 connected to the battery cell is the positive pole, while the other end of the second diode 22 connected to the battery cell is the negative pole. Through this arrangement, the charging and discharging of the battery cell can be distinguished, and the circuit can be protected at the same time.

[0037] One end of the capacitor 3 is grounded, and the other end is electrically connected to the first connection end and the second connection end. The single battery cell is electrically connected to the capacitor 3 only through the discharge control module 1 and one of the recharge control modules 2.

[0038] When the voltage of a certain battery cell is too high, the first switch 11 in the discharge control module 1 corresponding to the battery cell is closed, so that the battery cell is connected to the capacitor 3 and the capacitor 3 is charged. When the voltage of the battery cell drops to an equilibrium value, the first switch 11 is disconnected. When the voltage of a certain battery cell is too low, the second switch 21 of the recharge control module 2 corresponding to the battery cell is closed, so that the capacitor 3 charges the battery cell. After the voltage of the battery cell rises to an equilibrium value, the second switch 21 is disconnected. It should be noted that the recharge control module 2 and the discharge control module 1 on a single battery cell cannot be connected to the capacitor 3 at the same time to prevent the battery cell from being short-circuited and causing circuit damage.

[0039] As a preferred embodiment, an electric power module 4 is further provided, and the electric power module 4 is electrically connected to the capacitor 3 so as to store electric energy through the capacitor 3 for operation.

[0040] The power module 4 provided can be any electrical appliance on the new energy vehicle, so that the capacitor 3 supplies power to the power module 4, thereby consuming excess energy in the capacitor 3, so that the capacitor 3 can continue to be charged.

[0041] Specifically, the power module 4 includes a heating element 41, and the heating element 41 is electrically connected to the capacitor 3 to convert the electrical energy stored in the capacitor 3 into heat energy for release.

[0042] The heating element 41 in this embodiment is preferably a heating film in the battery pack. By supplying power to the heating film, the working environment temperature of the battery pack can be increased in a low temperature environment, thereby ensuring that the battery cell can work normally and extending its service life.

[0043] As a preferred embodiment, the power module 4 also includes a transistor 42, the emitter of the transistor 42 is electrically connected to the capacitor 3, the collector of the transistor 42 is electrically connected to the heating element 41, and the base of the transistor 42 is externally connected to a power supply.

[0044] Since the current generated by the capacitor 3 when supplying power to the heating element 41 is relatively small, an amplifier circuit is formed by adding the transistor 42 to amplify the current, and the external power supply can be a vehicle-mounted battery, a lead-acid battery, etc.

[0045] In this embodiment, a control switch 5 is also provided. The control switch 5 is provided in the external wiring of the capacitor 3 and is electrically connected to the power consumption module 4 and the recharging control module 2. The control switch 5 is used to electrically connect one of the power consumption module 4 and the recharging control module 2 to the capacitor 3.

[0046] The control switch 5 is similar to a single-pole double-throw switch. By connecting two contacts, the power module 4 and the recharge control module 2 are switched to connect to the capacitor 3, thereby controlling the power module 4 to start, or charging the low-voltage battery cell.

[0047] like Figure 1 As shown, the battery management system of the present utility model includes the above-mentioned active cell power equalization device.

[0048] Specifically, it also includes a main control module 6, which is coupled with the discharge control module 1 and the recharge control module 2 to control one of the discharge control module 1 and the recharge control module 2 to form a path between the capacitor 3 and the battery cell.

[0049] The main control module 6 can be a BMS in a new energy vehicle. By setting two relays, the BMS controls the two relays, and the two relays control the first switch 11 and the second switch 12 respectively. Figure 1 In the example, the two relays are M relay and N relay.

[0050] In addition, a relay k1 is provided, and the BMS realizes the switching action between the power consumption module 4 and the recharging control module 2 by controlling the relay k1.

[0051] It should be noted that the BMS itself has the function of detecting the voltage and heat of the battery cell, so it can directly determine whether to charge or discharge a certain battery cell through the detection data, and then achieve control.

[0052] The battery pack of the utility model includes the above-mentioned battery management system.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery cell active equalization device, characterized in that: It comprises a discharge control module (1), a recharge control module (2) and a capacitor (3), wherein: The discharge control module (1) comprises a first connection end and an input end, the first connection end is electrically connected to the battery cell, and the discharge control module (1) is used to discharge the battery cell outward and limit current backflow; The recharge control module (2) comprises a second connection end and an output end, the second connection end is electrically connected to the battery cell, and the recharge control module (2) is used to enable the current to charge the battery cell and limit the current backflow; One end of the capacitor (3) is grounded, and the other end is electrically connected to the first connection end and the second connection end; a single battery cell is electrically connected to one of the recharge control modules (2) and the capacitor (3) only through the discharge control module (1).

2. The active cell charge equalization device according to claim 1, characterized in that: The discharge control module (1) comprises a first switch (11) and a first diode (12), wherein: The first switch (11) is arranged on a connection line between the battery cell and the capacitor (3), and the first switch (11) is used to control the connection and disconnection between the battery cell and the capacitor (3); The first diode (12) is arranged on a connection line between the battery cell and the capacitor (3), so that when the first switch (11) is closed, the battery cell can only charge the capacitor (3).

3. The active cell charge equalization device according to claim 1, characterized in that: The recharging control module (2) comprises a second switch (21) and a second diode (22), wherein: The second switch (21) is arranged on a connection line between the battery cell and the capacitor (3), and the second switch (21) is used to control the connection and disconnection between the battery cell and the capacitor (3); The second diode (22) is arranged on a connection line between the battery cell and the capacitor (3), so that when the second switch (21) is closed, the capacitor (3) can only charge the battery cell.

4. The active cell charge equalization device according to claim 1, characterized in that: It also includes an electricity-using module (4), which is electrically connected to the capacitor (3) so as to store electrical energy through the capacitor (3) to perform operations.

5. The active cell charge equalization device according to claim 4, characterized in that: The power module (4) comprises a heating element (41), and the heating element (41) is electrically connected to the capacitor (3) to convert the electrical energy stored in the capacitor (3) into thermal energy for release.

6. The active cell charge equalization device according to claim 5, characterized in that: The power module (4) further comprises a triode (42), the emitter of the triode (42) being electrically connected to the capacitor (3), the collector of the triode (42) being electrically connected to the heating element (41), and the base of the triode (42) being externally connected to a power source.

7. The active cell charge equalization device according to claim 4, characterized in that: The invention also comprises a control switch (5), wherein the control switch (5) is arranged on an external wiring circuit of the capacitor (3) and is electrically connected to the power consumption module (4) and the recharging control module (2), and the control switch (5) is used to electrically connect one of the power consumption module (4) and the recharging control module (2) to the capacitor (3).

8. A battery management system, characterized in that: The invention comprises the battery cell active charge equalization device according to any one of claims 1 to 7.

9. The battery management system according to claim 8, characterized in that: The invention also comprises a main control module (6), wherein the main control module (6) is connected with the discharge control module (1) and the recharge control module (2) to control one of the discharge control module (1) and the recharge control module (2) to form a path between the capacitor (3) and the battery cell.

10. A battery pack, characterized in that: A battery management system comprising any one of claims 8-9.

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