Battery equalization circuit, battery management system and electric device

Abstract

The utility model provides a battery equalization circuit, a battery management system and an electric device, in the battery equalization circuit, a first power supply loop is formed between an energy storage module and a first battery pack, a second power supply loop is formed between the energy storage module and a second battery pack, a first control module is connected to the first power supply loop, and a second control module is connected to the second power supply loop. The first control module is connected to the first power supply loop and used for controlling on-off of the first power supply loop, and the second control module is connected to the second power supply loop and used for controlling on-off of the second power supply loop. In a certain moment or a certain time period in the working process of the battery equalization circuit, the first control module and the second control module control one of the first power supply loop and the second power supply loop to be switched on and the other one to be switched off, so that the first battery pack or the second battery pack charges the energy storage module; or the energy storage module discharges the first battery pack or the second battery pack, thereby realizing equalization of the battery pack, improving the charge-discharge capability of the battery pack and prolonging the service life of the battery pack.

Description

Technical Field

[0001] The utility model relates to the technical field of battery power supply, in particular to a battery equalization circuit, a battery management system and an electric device. Background Art

[0002] As a commonly used energy storage device, a battery pack includes multiple battery cells connected in series. Multiple battery cells are prone to power imbalance during the charging and discharging process. The power imbalance will cause the batteries with more power to be fully charged prematurely and charging to be cut off when charging, and the batteries with less power cannot be fully charged. Correspondingly, during discharging, the batteries with less power will be exhausted prematurely and discharging will be cut off, and the batteries with more power cannot be fully discharged, which will greatly reduce the usable energy of the entire battery pack, seriously affecting the charging and discharging capabilities and service life of the battery pack. Utility Model Content

[0003] In view of this, the utility model provides a battery balancing circuit, a battery management system and an electrical device, so as to at least solve the problem in the prior art that the battery system is easily unbalanced during the charging and discharging process of the power battery, thereby affecting the battery charging and discharging capacity.

[0004] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0005] The utility model provides a battery balancing circuit, including a battery pack, an energy storage module, a first control module and a second control module; the battery pack includes a first battery group and a second battery group, the first battery group is electrically connected to the energy storage module to form a first power supply circuit, and the second battery group is electrically connected to the energy storage module to form a second power supply circuit; the first control module is connected to the first power supply circuit, and is used to control the on and off of the first power supply circuit; the second control module is connected to the second power supply circuit, and is used to control the on and off of the second power supply circuit; at the same time, one of the first power supply circuit and the second power supply circuit is turned on, and the other is turned off.

[0006] Optionally, the energy storage module is an inductive component.

[0007] Optionally, the energy storage module is a motor winding.

[0008] Optionally, the battery balancing circuit further includes a control switch; the control switch is connected to the first power supply circuit, and is used to control the conduction or disconnection of the first power supply circuit; and / or the control switch is connected to the second power supply circuit, and is used to control the conduction or disconnection of the second power supply circuit.

[0009] Optionally, the first control module and the second control module are motor controllers.

[0010] Optionally, the battery balancing circuit further includes a protection capacitor, a first electrode of the protection capacitor is electrically connected to the first battery group, and a second electrode of the protection capacitor is electrically connected to the second battery group.

[0011] Optionally, the output voltage of the first battery group is greater than the output voltage of the second battery group.

[0012] The utility model also provides a battery management system, comprising any of the above-mentioned battery equalization circuits.

[0013] The utility model also provides an electric device, comprising the above-mentioned battery management system.

[0014] Compared with the prior art, the battery balancing circuit described in the utility model has the following advantages:

[0015] In the battery balancing circuit of the utility model, a first power supply circuit is formed between the energy storage module and the first battery pack, a second power supply circuit is formed between the energy storage module and the second battery pack, a first control module is connected to the first power supply circuit, and is used to control the on and off of the first power supply circuit, and a second control module is connected to the second power supply circuit, and is used to control the on and off of the second power supply circuit. At a certain moment or a certain time period during the operation of the battery balancing circuit, the first control module and the second control module control one of the first power supply circuit and the second power supply circuit to be turned on and the other to be turned off, so that the first battery pack or the second battery pack charges the energy storage module, or the energy storage module discharges the first battery pack or the second battery pack, thereby achieving the balance of the battery pack and improving the charging and discharging capacity and service life of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0017] Figure 1 It is a structural schematic diagram of a battery equalization circuit according to an embodiment of the utility model;

[0018] Figure 2 It is a structural schematic diagram of a battery balancing circuit in which an energy storage module is an inductor component according to an embodiment of the utility model;

[0019] Figure 3 This is a schematic diagram of the structure of a battery balancing circuit in which an energy storage module is a motor winding in an embodiment of the utility model;

[0020] Figure 4 It is a circuit diagram of a battery balancing circuit in which the energy storage module is an inductor component in an embodiment of the utility model;

[0021] Figure 5 It is a circuit diagram of a battery equalization circuit in which the energy storage module is a motor winding in an embodiment of the utility model;

[0022] Figure 6 is a circuit diagram of a battery equalization circuit for discharging a first battery pack in an embodiment of the utility model;

[0023] Figure 7 It is a circuit diagram of a battery equalization circuit for charging the second battery pack in an embodiment of the utility model. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] The terms "first", "second", etc. in the specification and claims of the present utility model are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the present utility model can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more.

[0026] It should be understood that the reference to "some embodiments" throughout the specification means that specific features, structures or characteristics related to the embodiments are included in at least one embodiment of the utility model. Therefore, the "in some embodiments" appearing in various places throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner.

[0027] The following describes in detail a battery balancing circuit, a battery management system and an electric device provided by the utility model by listing specific embodiments.

[0028] Reference Figure 1The utility model provides a battery balancing circuit including a battery pack 1, an energy storage module 2, a first control module 31 and a second control module 32; the battery pack 1 includes a first battery group 11 and a second battery group 12, the first battery group 11 is electrically connected to the energy storage module 2 to form a first power supply circuit, and the second battery group 12 is electrically connected to the energy storage module 2 to form a second power supply circuit; the first control module 31 is connected to the first power supply circuit to control the on and off of the first power supply circuit; the second control module 32 is connected to the second power supply circuit to control the on and off of the second power supply circuit; at the same time, one of the first power supply circuit and the second power supply circuit is turned on, and the other is turned off.

[0029] In some embodiments, the battery pack 1 is the main charging and discharging unit in the circuit. The battery pack 1 is composed of a plurality of battery cells connected in series, wherein some of the battery cells connected in series constitute a first battery group 11, and some of the battery cells connected in series constitute a second battery group 12. The plurality of battery cells can be divided into two groups, that is, the battery pack 1 only includes two battery groups. The plurality of battery cells can also be divided into multiple groups, that is, the battery pack 1 includes multiple battery groups. For example, assuming that the battery pack 1 includes 200 battery cells connected in series, 120 of the 200 battery cells connected in series form a group, and the remaining 80 battery cells connected in series form a group, then the two groups are the first battery group 11 and the second battery group 12; assuming that 120 of the 200 battery cells connected in series form a group, the remaining 50 battery cells connected in series form a group, and 30 battery cells connected in series form a group, then any two of the three groups are the first battery group 11 and the second battery group 12. Since the multiple cells in the battery pack 1 are connected in series, when the available state of charge (SOC) of the remaining charge of the first battery pack 11 and the available state of charge of the second battery pack 12 are inconsistent, balancing is triggered, and the battery balancing circuit starts to work, compensating the battery pack with a low available state of charge SOC, thereby raising the lower limit of the available state of charge of the battery, maintaining the working state of the battery, and improving the charging and discharging capacity of the battery. For the convenience of description, the embodiments of the utility model are described in the following using the English abbreviation SOC instead of the available state of charge.

[0030] like Figure 1As shown, the energy storage module 2 is electrically connected to the first battery group 11 and the second battery group 12 respectively, the energy storage module 2 has a power storage function, a first power supply circuit is formed between the energy storage module 2 and the first battery group 11, and a second power supply circuit is formed between the energy storage module 2 and the second battery group 12. The first control module 31 and the second control module 32 have control functions. The first control module 31 is arranged on the first power supply circuit, which can be connected between the energy storage module 2 and the first battery group 11, and can also be connected between the energy storage module 2 and the first battery group 11. The first control module 31 can control the on-off of the first power supply circuit between the energy storage module 2 and the first battery group 11. The second control module 32 is arranged on the second power supply circuit, which can be connected between the energy storage module 2 and the second battery group 12, and can also be connected between the energy storage module 2 and the second battery group 12. The second control module 32 can control the on-off of the second power supply circuit between the energy storage module 2 and the second battery group 12. At a certain moment or a certain time period during the operation of the battery balancing circuit, the first control module 31 and the second control module 32 control one of the first power supply circuit and the second power supply circuit to be turned on and the other to be turned off, that is, at a certain moment or a certain time period, when the first power supply circuit is turned on and works, the second power supply circuit is turned off and does not work, and when the first power supply circuit is turned off and does not work, the second power supply circuit is turned on and works.

[0031] For example, in some embodiments, assuming that the SOC of the first battery group 11 is greater than the SOC of the second battery group 12 at a certain moment, the battery balancing circuit is triggered to start working. In the t1 time period, the first control module 31 controls the first power supply circuit to be turned on, and the second control module 32 controls the second power supply circuit to be turned off. In this time period, the first battery group 11 starts to discharge the energy storage module 2, the amount of electricity stored in the energy storage module 2 gradually increases, and the SOC of the first battery group 11 gradually decreases; in the t2 time period, the first control module 31 controls the first power supply circuit to be turned off, and the second control module 32 controls the second power supply circuit to be turned on. In this time period, the energy storage module 2 starts to discharge the second battery group 12, the amount of electricity stored in the energy storage module 2 gradually decreases, and the SOC of the second battery group 12 gradually increases. Wherein t1 is the time period before t2, t1 and t2 can be two consecutive time periods, or two time periods with a certain time interval, which is not limited in this embodiment.

[0032] In other embodiments, assuming that the SOC of the first battery pack 11 is less than the SOC of the second battery pack 12 at a certain moment, the battery balancing circuit is triggered to start working. In the t1 time period, the first control module 31 controls the first power supply circuit to be disconnected, and the second control module 32 controls the second power supply circuit to be turned on. In this time period, the second battery pack 12 starts to discharge the energy storage module 2, the amount of electricity stored in the energy storage module 2 gradually increases, and the SOC of the second battery pack 12 gradually decreases; in the t2 time period, the first control module 31 controls the first power supply circuit to be turned on, and the second control module 32 controls the second power supply circuit to be turned off. In this time period, the energy storage module 2 starts to discharge the first battery pack 11, the amount of electricity stored in the energy storage module 2 gradually decreases, and the SOC of the first battery pack 11 gradually increases. Wherein t1 is the time period before t2, and t1 and t2 can be two consecutive time periods, or two time periods with a certain time interval, which is not limited in this embodiment.

[0033] It should be noted that, in the above two embodiments, a threshold value of the difference between the SOC of the first battery group 11 and the SOC of the second battery group 12 can be pre-set, and balancing is triggered when the difference between the SOC of the first battery group 11 and the SOC of the second battery group 12 is outside the threshold value. When the difference between the SOC of the first battery group 11 and the SOC of the second battery group 12 reaches the threshold value or is less than the threshold value, balancing can be stopped, the first power supply circuit and the second power supply circuit are both disconnected, and the energy storage module 2 is no longer charged and discharged. If the power stored in the energy storage module 2 has not been exhausted, the energy storage module 2 will temporarily store the unexhausted power to prepare for the next balancing. Of course, if the power stored in the energy storage module 2 is exhausted in advance, the battery balancing circuit will perform the next cycle, and the first battery group 11 or the second battery group 12 will continue to charge the energy storage module 2.

[0034] In addition, in some embodiments, the battery management system may include the aforementioned battery balancing circuit, and a monitoring unit for monitoring the battery group in the battery balancing circuit. The monitoring unit may monitor the SOC of the first battery group 11 and the second battery group 12, and control the first control module 31 and the second control module 32 to operate according to the SOC of the first battery group 11 and the SOC of the second battery group 12, so that the first control module 31 and the second control module 32 turn on or off the corresponding power supply circuit. In some embodiments, during the process of the first battery group 11 or the second battery group 12 charging the energy storage module 2 and the energy storage module 2 discharging the first battery group 11 or the second battery group 12, a small current may flow to avoid overcharging or over-discharging the first battery group 11, the second battery group 12 and the energy storage module 2, so as to ensure the battery balancing effect. In other embodiments, the size of the circulating current may also be reasonably adjusted according to actual use requirements, which will not be repeated here.

[0035] Optionally, refer to Figure 2 and Figure 4 , the energy storage module 2 is an inductor component L.

[0036] In some embodiments, the inductor component L can store energy by utilizing the magnetic field generated when the coil current changes. Figure 2 The structure diagram of using the inductor component L as the energy storage module 2 is shown. Figure 4 The circuit diagram of using the inductor component L as the energy storage module 2 is shown. In addition, in other embodiments, a capacitor component composed of capacitors and other electronic components can also be used to replace the inductor component L. The capacitor component has the same or similar function as the inductor component, and balances and adjusts the charging and discharging process of the first battery group 11 and the second battery group 12 in the above-mentioned battery balancing circuit.

[0037] Optionally, refer to Figure 3 The energy storage module 2 is a motor winding 21, and the first control module 31 and the second control module 32 are motor controllers.

[0038] In some embodiments, Figure 3 As shown, the battery balancing circuit can reuse the motor control of the whole vehicle, introduce the motor winding 21 and the motor controller, and the motor controller includes a first motor controller 310 and a second motor controller 320. The first motor controller 310 acts as a first control module 31, and the second motor controller 320 acts as a second control module 32. The motor winding 21 is electrically connected to the first battery pack 11 to form a first power supply circuit, and the motor winding 21 is electrically connected to the second battery pack 12 to form a second power supply circuit. The first motor controller 310 is connected to the first power supply circuit. In some embodiments, the first motor controller 310 can be connected between the motor winding 21 and the first battery pack 11 to control the on and off of the first power supply circuit; the second motor controller 320 is connected to the second power supply circuit. In some embodiments, the second motor controller 320 can be connected between the motor winding 21 and the second battery pack 12 to control the on and off of the second power supply circuit. In this embodiment, the battery balancing circuit reuses the motor control of the whole vehicle, which can improve the effective utilization rate of the vehicle components and control the processing cost of the battery balancing circuit. Of course, the motor in this embodiment is not limited to the power motor of the vehicle, but can also be other motors with driving functions, such as a brake motor, a power motor, a steering motor, etc.

[0039] Figure 5 The circuit diagram of the motor winding 21 using the inductor component L is shown. Figure 5 As shown in L1, L2, and L3 in FIG. 1 , the first motor controller 310 is as follows: Figure 5 As shown in Q1, Q2 and Q3 in FIG. 1 , the second motor controller 320 is as follows: Figure 5The first motor controller 310 and the second motor controller 320 are three-phase bridge circuits, Q1, Q2 and Q3 are connected in parallel, and the source electrodes ( Figure 5 The source of Q1 is electrically connected to the motor winding L1, the source of Q2 is electrically connected to the motor winding L2, the source of Q3 is electrically connected to the motor winding L3, and the drains of Q1, Q2 and Q3 ( Figure 5 The first battery pack 11 is electrically connected to the first battery pack 11 (shown as "D" in the figure). Q4, Q5 and Q6 are connected in parallel with each other, the drain of Q4 is electrically connected to the motor winding L1, the drain of Q5 is electrically connected to the motor winding L2, the drain of Q6 is electrically connected to the motor winding L3, and the sources of Q4, Q5 and Q6 are electrically connected to the second battery pack 12.

[0040] For example, in some embodiments, Figure 6 As shown, assuming that the SOC of the first battery pack 11 is greater than the SOC of the second battery pack 12 at a certain moment, the battery balancing circuit is triggered to start working. During the time period t1, the first motor controller 310 ( Figure 6 Q1, Q2 and Q3 in the first power supply circuit) control the first power supply circuit to be turned on, and the second motor controller 320 ( Figure 6 Q4, Q5 and Q6 in the control circuit 20 to disconnect the second power supply circuit. During this period, the first battery pack 11 starts to supply power to the motor winding 21 ( Figure 6 As shown in L1, L2, L3 in the figure, discharges to form Figure 6 In the equalization loop shown by the arrow in the middle, the SOC of the first battery group 11 gradually decreases; Figure 7 As shown, during the time period t2, the first motor controller 310 ( Figure 7 Q1, Q2 and Q3 in the first power supply circuit) control the first power supply circuit to be disconnected, and the second motor controller 320 ( Figure 7 Q4, Q5 and Q6 in the circuit) control the second power supply circuit to be turned on. During this period of time, the motor winding 21 ( Figure 7 As shown in L1, L2, and L3 in FIG. 1 , the second battery pack 12 begins to discharge, forming a Figure 7 In the balancing loop shown by the arrow, the power stored in the motor winding 21 gradually decreases, and the SOC of the second battery pack 12 gradually increases. Wherein t1 is the time period before t2, t1 and t2 can be two consecutive time periods, or two time periods with a certain time interval, which is not limited in this embodiment.

[0041] Optionally, refer to Figure 3The battery balancing circuit further includes a control switch 4; the control switch 4 is connected to the first power supply circuit, and is used to control the conduction or disconnection of the first power supply circuit; and / or the control switch 4 is connected to the second power supply circuit, and is used to control the conduction or disconnection of the second power supply circuit.

[0042] In some embodiments, the control switch 4 can be connected to the first power supply circuit to control the conduction or disconnection of the first power supply circuit, and the control switch 4 can also be connected to the second power supply circuit to control the conduction or disconnection of the second power supply circuit. Alternatively, the control switch 4 can be connected to a common path of the first power supply circuit and the second power supply circuit, and connected between the power motor and the first battery pack 11 and the second battery pack 12 to simultaneously control the conduction or disconnection of the first power supply circuit and the second power supply circuit. It should be noted that in an embodiment in which the inductor component L reuses the motor winding 21 of the entire vehicle, it can be considered to set a control switch 4 to cut off the balancing circuit when the motor performs a driving function. Figure 5 In the circuit diagram of the inductor component L multiplexing the motor winding 21, the control switch 4 is as shown. Figure 5 As shown in K, the on / off of the first power supply circuit formed by Q1, Q2, Q3, L1, L2, L3 and the first battery group 11 and the on / off of the second power supply circuit formed by Q4, Q5, Q6, L1, L2, L3 and the second battery group 12 can be controlled.

[0043] like Figure 3 As shown, in the case where the energy storage module 2 is the motor winding 21, when the control switch 4 and the first motor controller 310 and the second motor controller 320 are closed, the first power supply circuit and the second power supply circuit are turned on, the motor plays a balancing role, and the motor winding 21 is charged by the first battery pack 11 or the second battery pack 12, or the motor winding 21 discharges the first battery pack 11 or the second battery pack 12; when the control switch 4 is disconnected, the first power supply circuit and the second power supply circuit are disconnected, at this time, the power motor does not participate in the balancing, and the power motor plays a driving role to drive the vehicle to travel. Exemplarily, when the vehicle is in a driving condition, the control switch 4 is disconnected, so that the power motor plays a driving role and does not play a balancing role, thereby providing driving force for the vehicle to travel. When the vehicle is in a stopped state, the control switch 4 is turned on, so that the power motor mainly plays a balancing role and does not play a driving role, and the battery pack 1 is balanced, and the storage capacity and charging and discharging capacity of the battery pack 1 are improved, thereby improving the endurance of the vehicle.

[0044] Optionally, refer to Figure 4The first control module 31 and the second control module 32 are NPN type MOS tubes; the drain of the first control module 31 is electrically connected to the first battery pack 11, and the source of the first control module 31 is electrically connected to the energy storage module 2; the drain of the second control module 32 is electrically connected to the energy storage module 2, and the source of the second control module 32 is electrically connected to the second battery pack 12.

[0045] In some embodiments, Figure 4 As shown, when the energy storage module 2 uses the inductor component L, the first control module 31 and the second control module 32 can use NPN type MOS tubes. Figure 4 As shown in Q1 in FIG. 1 , the second control module 32 is as follows: Figure 4 As shown in Q2, the drain of Q1 ( Figure 4 The source of Q1 (shown as "D" in FIG. Figure 4 The drain of Q2 is electrically connected to the inductor component L, and the source of Q2 is electrically connected to the second battery pack 12. The NPN MOS tube has a gate ( Figure 4 The gates of Q1 and Q2 are used to connect to a battery management system, which can monitor the SOC of the first battery pack 11 and the second battery pack 12, and control the on and off of Q1 and Q2 according to the SOC of the first battery pack 11 and the second battery pack 12.

[0046] Exemplarily, assuming that the SOC of the first battery group 11 is greater than the SOC of the second battery group 12, during the time period t1, the control unit in the battery management system outputs a high level to the gate of Q1, so that the voltage difference between the gate and the source of Q1 is greater than the conduction threshold, so that Q1 is turned on and the first power supply circuit is turned on. At the same time, the battery management system outputs a low level to the gate of Q2, so that the voltage difference between the gate and the source of Q2 is less than the conduction threshold, so that Q2 is disconnected, and the second power supply circuit is disconnected, so that the first battery group 11 discharges the inductor component L, and no current flows between the second battery group 12 and the inductor component L. Similarly, during the time period t2, the battery management system outputs a low level to the gate of Q1, so that Q1 is disconnected and the first power supply circuit is disconnected. At the same time, the battery management system outputs a high level to the gate of Q2, so that Q2 is turned on, and the second power supply circuit is turned on, so that the inductor component L discharges the second battery group 12, and no current flows between the first battery group 11 and the inductor component L.

[0047] Optionally, the first control module 31 and the second control module 32 are PNP type MOS tubes; the source of the first control module 31 is electrically connected to the first battery group 11, and the drain of the first control module 31 is electrically connected to the energy storage module 2; the source of the second control module 32 is electrically connected to the energy storage module 2, and the drain of the second control module 32 is electrically connected to the second battery group 12.

[0048] In some embodiments, when the energy storage module 2 uses the inductor component L, the first control module 31 and the second control module 32 can also use a PNP type MOS tube. For the first control module 31, the source of the MOS tube is electrically connected to the first battery pack 11, and the drain is electrically connected to the inductor component L. For the second control module 32, the source of the MOS tube is electrically connected to the inductor component L, and the drain is electrically connected to the second battery pack 12. The PNP type MOS tube is turned on when the voltage difference between its gate voltage and source voltage is less than the turn-on threshold, wherein the gate of the MOS tube is used to connect to the battery management system, and the battery management system controls the on and off of the MOS tube according to the SOC size of the first battery pack 11 and the second battery pack 12 monitored. The turn-on condition of the PNP type MOS tube is opposite to the turn-on condition of the NPN type MOS tube, and its control principle is the same as the aforementioned NPN type MOS, which will not be repeated in this embodiment.

[0049] Optionally, refer to Figure 2 and Figure 3 The battery balancing circuit further includes a protection capacitor 5 , a first electrode of the protection capacitor 5 is electrically connected to the first battery group 11 , and a second electrode of the protection capacitor 5 is electrically connected to the second battery group 12 .

[0050] In some embodiments, the protection capacitor 5 is as follows Figure 4 and Figure 5 As shown in C1 in the figure, the first electrode of the protection capacitor 5 is electrically connected to the positive electrode of the first battery group 11, and the second electrode of the protection capacitor 5 is electrically connected to the negative electrode of the second battery group 12. The setting of the protection capacitor 5 can protect the battery balancing circuit, thereby protecting the energy storage module 2 and improving the reliability of the battery balancing circuit.

[0051] Optionally, the output voltage of the first battery group 11 is greater than the output voltage of the second battery group 12 .

[0052] In some embodiments, in actual applications, if the output voltage of the first battery pack 11 is greater than the output voltage of the second battery pack 12, the number of cells included in the first battery pack 11 is generally greater than the number of cells included in the second battery pack 12. In the case where the output voltage of the first battery pack 11 is greater than the output voltage of the second battery pack 12, the second battery pack 12 can constitute a low-voltage redundant system for powering the load. Specifically, the vehicle power supply system generally includes a high-voltage system and a low-voltage system. The high-voltage system can provide a voltage of about 200V to 800V, which is used to power high-power loads such as high-voltage control boxes, power motors, motor controllers, on-board chargers, electric air-conditioning compressors, and DC converters. The low-voltage system can provide a voltage of about 12V, which is used to power low-power loads such as cigarette lighters, mobile phones, navigators, and driving recorders. However, since some loads mounted on the low-voltage system still use a large amount of power, it is easy to cause excessive current in the low-voltage system, causing a large amount of heat, which is not conducive to the working safety of the low-voltage system. Therefore, if Figure 4 As shown, in this embodiment, the second battery group 12 in the battery pack 1 is selected to form a low-voltage redundant system, through which part of the load of the low-voltage system is shared to reduce the current of the low-voltage system and reduce heat generation.

[0053] The voltage of the low-voltage redundant system can be set according to actual needs. In some embodiments, the rated voltage of each cell of some lithium iron phosphate batteries is about 3.2V. If a 48V low-voltage redundant system is required, a total of about 15 cells are required, so the second battery pack 12 is set to include 15 cells connected in series, and the energy storage module 2 is connected to the positive electrode of the 15th cell; if a 60V low-voltage redundant system is required, a total of about 19 cells are required, so the second battery pack 12 is set to include 19 cells connected in series, and the energy storage module 2 is connected to the positive electrode of the 19th cell. This embodiment directly selects the second battery pack 12 in the battery pack 1 to form a low-voltage redundant system. Compared with the design of the redundant system in the traditional way, the setting of the isolated buck converter is cancelled, the volume of the low-voltage redundant system is reduced, and the setting cost of the low-voltage redundant system is saved.

[0054] The utility model also provides a battery management system, comprising any of the battery balancing circuits described above; the battery management system is used to monitor the available state of the remaining charge of the first battery group 11 and the available state of the remaining charge of the second battery group 12, and trigger the battery balancing circuit to work according to the available state of the remaining charge of the first battery group 11 and the available state of the remaining charge of the second battery group 12.

[0055] In some embodiments, the battery management system is closely integrated with the power battery pack 1 of the electric vehicle, and the voltage, current and temperature of the battery are detected in real time through sensors, leakage detection, thermal management, battery balancing management, alarm reminder, calculation of battery remaining capacity, discharge power, reporting of battery degradation degree and remaining capacity state, and the maximum output power can be controlled by algorithm according to the voltage, current and temperature of the battery to obtain the maximum driving mileage, and the charger can be controlled by algorithm to charge with the optimal current, and the on-board master controller, motor controller, energy control system, on-board display system, etc. can be communicated in real time through the bus interface. Among them, the battery management system applies the battery balancing circuit of any of the above embodiments to implement battery balancing management, and the battery management system can monitor the available state of the remaining charge of the first battery group 11 and the available state of the remaining charge of the second battery group 12, that is, monitor the SOC of the first battery group 11 and the SOC of the second battery group 12, and trigger the battery balancing circuit to work according to the SOC of the first battery group 11 and the SOC of the second battery group 12, and its working conditions are as described in the above embodiments, and this embodiment will not be repeated here.

[0056] The utility model also provides an electrical device, comprising the above-mentioned battery management system.

[0057] In some embodiments, the power-consuming device includes an energy storage device or an electric vehicle, etc. The energy storage device includes an energy storage cabinet, a control cabinet, an integrated cabinet, etc. The electric vehicle includes a pure electric vehicle and a hybrid vehicle. The power-consuming device is applied with the aforementioned battery management system. The battery management system can perform balancing management on the power battery pack 1 to improve the charging and discharging capacity and service life of the power battery pack 1.

[0058] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0059] 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 balancing circuit, characterized in that: It comprises a battery pack (1), an energy storage module (2), a first control module (31) and a second control module (32); The battery pack (1) comprises a first battery group (11) and a second battery group (12), the first battery group (11) being electrically connected to the energy storage module (2) to form a first power supply circuit, and the second battery group (12) being electrically connected to the energy storage module (2) to form a second power supply circuit; The first control module (31) is connected to the first power supply circuit and is used to control the on and off of the first power supply circuit; the second control module (32) is connected to the second power supply circuit and is used to control the on and off of the second power supply circuit; At the same time, one of the first power supply circuit and the second power supply circuit is turned on, and the other is turned off.

2. The battery equalization circuit according to claim 1, characterized in that: The energy storage module (2) is an inductor component.

3. The battery equalization circuit according to claim 2, characterized in that: The energy storage module (2) is a motor winding (21).

4. The battery equalization circuit according to claim 3, characterized in that: Also includes a control switch (4); The control switch (4) is connected to the first power supply circuit and is used to control the on or off of the first power supply circuit; And / or, the control switch is connected to the second power supply circuit, and is used to control the conduction or disconnection of the second power supply circuit.

5. The battery equalization circuit according to claim 3, characterized in that: The first control module (31) and the second control module (32) are motor controllers.

6. The battery equalization circuit according to claim 1, characterized in that: It also includes a protection capacitor (5), a first electrode of the protection capacitor (5) being electrically connected to the first battery group (11), and a second electrode of the protection capacitor (5) being electrically connected to the second battery group (12).

7. The battery equalization circuit according to claim 1, characterized in that: The output voltage of the first battery group (11) is greater than the output voltage of the second battery group (12).

8. A battery management system, characterized in that: The battery balancing circuit comprises the battery balancing circuit according to any one of claims 1 to 7.

9. An electrical device, characterized in that: Including the battery management system as described in claim 8.

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