Battery pack parallel control device, method, bms, battery pack and power consuming device

Abstract

The application provides a battery pack parallel control device, method, BMS, battery pack and electric equipment, and relates to the technical field of batteries. The battery pack parallel control device comprises a load and a micro control unit; a first switch, the first switch and the load are configured in series between a negative output end of a battery pack and a positive electrode of a battery module in the battery pack; wherein the first switch can perform on-off operation in response to a control signal of the micro control unit; a first voltage detection circuit is electrically connected to the micro control unit, and the first voltage detection circuit is further configured to be electrically connected to the negative output end to detect the voltage of the negative output end and output a first detection signal representing the voltage of the negative output end to the micro control unit; and the micro control unit is configured to judge whether to allow the battery pack to be parallel connected according to the first detection signal. According to the scheme of the application, the parallel connection control of the battery pack can no longer depend on the communication between the battery packs, and reliable parallel connection management can be performed even when the communication of the battery packs is abnormal.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery pack parallel operation control device, method, BMS, battery pack, and electrical equipment. Background Technology

[0002] When two or more battery packs need to be charged or discharged to an external load at the same time, the two battery packs can be connected in parallel to achieve parallel operation of the battery packs.

[0003] During parallel operation of battery packs, the battery packs need to communicate with each other to understand their respective battery status and determine whether parallel operation is feasible. However, communication breakdowns may occur. If parallel operation proceeds despite poor communication, the inconsistent battery pack states and charge levels may lead to circulating current charging risks. Under conditions of high or low temperatures or high charge levels, circulating current charging can cause irreversible damage to the battery cells. Therefore, current battery pack parallel operation control heavily relies on communication between battery packs, making reliable parallel operation management impossible when communication is abnormal. Summary of the Invention

[0004] The purpose of this application is to provide a battery pack parallel control device, method, BMS, battery pack, and electrical equipment to improve the above-mentioned problems.

[0005] A first aspect of this application provides a battery pack parallel operation control device, including a load and a microcontroller unit; a first switch configured to be connected in series with the load between the negative output terminal of the battery pack and the positive terminal of a battery module in the battery pack; wherein the first switch is capable of performing an on / off operation in response to a control signal from the microcontroller unit; a first voltage detection circuit electrically connected to the microcontroller unit, the first voltage detection circuit being further configured to be electrically connected to the negative output terminal to detect the voltage at the negative output terminal and output a first detection signal to the microcontroller unit, the first detection signal being used to characterize the voltage at the negative output terminal; the microcontroller unit is configured to determine whether parallel operation of the battery pack is permitted based on the first detection signal.

[0006] In the above implementation structure, the voltage at the negative output terminal is detected by a first voltage detection circuit, and a first detection signal characterizing the voltage at the negative output terminal is output to the microcontroller. This allows the microcontroller to obtain the voltage value at the negative output terminal, thereby determining the voltage relationship between the battery packs and ultimately whether the battery packs can be paralleled. Based on this implementation structure, reliable parallel management can be performed even when the battery packs cannot communicate normally.

[0007] In a first alternative embodiment of the first aspect described above, the first voltage detection circuit includes a first voltage detection sub-circuit, the first voltage detection sub-circuit including: a second switch electrically connected between the output terminal of the voltage converter and the microcontroller unit; and a third switch configured to be electrically connected between the control terminal of the second switch and the negative output terminal, the control terminal of the third switch being grounded.

[0008] With the above-described structure, when the voltage at the negative output terminal is negative, the third switch can be opened, thereby opening the second switch. This allows the microcontroller unit to receive the signal output by the voltage converter and determine that the voltage at the negative output terminal is negative.

[0009] In the first optional example of the first optional embodiment described above, the first voltage detection sub-circuit further includes: a first resistor, one end of which is electrically connected to the control terminal of the second switch and the second terminal of the third switch, and the other end of which is electrically connected to the output terminal of the voltage converter and the first terminal of the second switch, and the second terminal of the second switch is electrically connected to the microcontroller unit; a second resistor, one end of which is electrically connected to the first terminal of the third switch, and one end of which is also configured to be electrically connected to the negative output terminal, and the other end of which is electrically connected to the control terminal of the third switch and ground, and the second terminal of the third switch is electrically connected to the control terminal of the second switch.

[0010] In the above implementation structure, the first resistor constitutes the bias resistor of the second switch, and the second resistor constitutes the bias resistor of the third switch. Thus, the first resistor can ensure that the second switch operates within the designed operating range, and the second resistor can ensure that the third switch operates within the designed operating range.

[0011] In the above optional example, the first voltage detection sub-circuit further includes: a third resistor, one end of which is electrically connected to the control terminal of the second switch and the first resistor, and the other end of which is electrically connected to the second terminal of the third switch.

[0012] In the above implementation structure, the third resistor can limit the current between the control terminal of the second switch and the second terminal of the third switch, and can also act as a voltage divider to prevent the third switch from being damaged due to excessive current or voltage.

[0013] In the above optional example, the first voltage detection sub-circuit further includes: a fourth resistor; the control terminal of the third switch is grounded through the fourth resistor.

[0014] In the above implementation structure, the control terminal of the third switch is grounded through the fourth resistor. When the voltage at the negative output terminal is negative, the fourth resistor can limit the current flowing into the control terminal of the third switch and can also act as a voltage divider, thereby preventing the third switch from being damaged due to excessive current or voltage.

[0015] In the second optional example of the first optional embodiment described above, the first voltage detection sub-circuit further includes: a fifth resistor, one end of which is electrically connected to the microcontroller and the second switch respectively, and the other end of which is grounded.

[0016] In the above implementation structure, when the second switch is open, the voltage at the interface of the microcontroller can be pulled down to 0 through the fifth resistor, thereby preventing the interface of the microcontroller from being left floating.

[0017] In a third alternative example of the first alternative embodiment described above, the first voltage detection sub-circuit further includes a diode, the positive terminal of which is electrically connected to the third switch, and the negative terminal of which is configured to be electrically connected to the negative output terminal.

[0018] In the above-described structure, the diode prevents current from flowing back into the first voltage detection sub-circuit when the voltage at the negative output terminal is positive, thus protecting the safety of the first voltage detection sub-circuit. Simultaneously, because the diode has a turn-on voltage, its placement ensures that the absolute value of the negative voltage (the voltage value of a negative voltage) at the negative output terminal must exceed a certain value before the second and third switches are activated. This controls the allowable fluctuation range of the negative voltage at the negative output terminal, preventing the first voltage detection sub-circuit from being overly sensitive and detecting normal voltage fluctuations during operation as an abnormal negative voltage at the negative output terminal.

[0019] In a second alternative embodiment of the first aspect described above, the first voltage detection circuit includes a second voltage detection sub-circuit; the second voltage detection sub-circuit includes: a fourth switch and a first voltage divider branch, the fourth switch and the first voltage divider branch being configured to be connected in series between the negative output terminal and ground, the first voltage divider branch being electrically connected to the microcontroller unit; and a fifth switch, electrically connected between the control terminal of the fourth switch and ground, the control terminal of the fifth switch also being electrically connected to the microcontroller unit.

[0020] In the above implementation structure, when detection is required, the microcontroller only needs to send a control signal to the control terminal of the fifth switch to turn it on, thereby grounding the control terminal of the fourth switch. When the voltage at the negative output terminal is positive, the fourth switch turns on, allowing the microcontroller to acquire the voltage at the negative output terminal. Furthermore, under the action of the first voltage divider branch, the voltage at the negative output terminal will be reduced by a set ratio, ensuring that the first detection signal received by the microcontroller is within the voltage range detectable by the microcontroller.

[0021] In the first optional example of the second optional embodiment described above, the first voltage divider branch includes at least two resistors connected in series, and the node between the resistors connected in series is electrically connected to the microcontroller unit.

[0022] In the above implementation structure, a first voltage divider branch is formed by at least two resistors connected in series, and a microcontroller is electrically connected at the node between the resistors connected in series. This allows the voltage at the negative output terminal transmitted from the fourth switch to be divided according to a set ratio, so that the first detection signal received by the microcontroller is within the voltage range that the microcontroller can detect.

[0023] In a second optional example of the second optional embodiment described above, the second voltage detection sub-circuit further includes: a sixth resistor, one end of which is electrically connected to the control terminal of the fourth switch and the second terminal of the fifth switch, the other end of which is electrically connected to the first terminal of the fourth switch, and the other end of which is also configured to be electrically connected to the negative output terminal; the second terminal of the fourth switch is electrically connected to the first voltage divider branch; and a seventh resistor, one end of which is electrically connected to the first terminal of the fifth switch and ground, the other end of which is electrically connected to the control terminal of the fifth switch and the microcontroller unit, and the second terminal of the fifth switch is electrically connected to the control terminal of the fourth switch.

[0024] In the above implementation structure, the sixth resistor constitutes the bias resistor of the fourth switch, and the seventh resistor constitutes the bias resistor of the fifth switch. Thus, the sixth resistor ensures that the fourth switch operates within the designed operating range, and the seventh resistor ensures that the fifth switch operates within the designed operating range.

[0025] In one optional embodiment of the second optional example described above, the second voltage detection sub-circuit further includes: an eighth resistor, one end of which is electrically connected to the control terminal of the fourth switch and the sixth resistor, and the other end of which is electrically connected to the second terminal of the fifth switch.

[0026] In the above implementation structure, the eighth resistor can limit the current between the control terminal of the fourth switch and the second terminal of the fifth switch, and can also act as a voltage divider to prevent the fifth switch from being damaged due to excessive current or voltage.

[0027] In another alternative embodiment of the second alternative example described above, the second voltage detection sub-circuit further includes: a ninth resistor; the control terminal of the fifth switch is electrically connected to the microcontroller unit through the ninth resistor.

[0028] In the above implementation structure, the control terminal of the fifth switch is electrically connected to the microcontroller unit through the ninth resistor. When the microcontroller unit outputs a high-level control signal, the ninth resistor can limit the current flowing into the control terminal of the fifth switch and can also act as a voltage divider, thereby preventing the fifth switch from being damaged due to excessive current or voltage.

[0029] In a third alternative embodiment of the first aspect above, the battery pack parallel control device further includes: a second voltage detection circuit electrically connected to the microcontroller unit, the second voltage detection circuit being further configured to be electrically connected to the positive terminal of the battery module to detect the voltage of the positive terminal of the battery module and output a second detection signal to the microcontroller unit, the second detection signal being used to characterize the voltage of the positive terminal of the battery module.

[0030] In the above implementation structure, the voltage of the positive terminal of the battery module can be detected by the second voltage detection circuit, and a second detection signal characterizing the voltage of the positive terminal of the battery module is output to the microcontroller. This allows the microcontroller to effectively sense both the voltage value at the negative terminal and the voltage at the positive terminal of the battery module. Based on the voltage values ​​at the negative terminal and the positive terminal of the battery module, the microcontroller can better determine the battery status between battery packs and thus determine whether the battery packs can be paralleled. Based on this implementation structure, parallel control of battery packs no longer relies on communication between battery packs, and reliable parallel management can be performed even when battery pack communication is abnormal.

[0031] In the first optional example of the third optional embodiment described above, the second voltage detection circuit includes: a sixth switch and a second voltage divider branch, the sixth switch and the second voltage divider branch being configured to be connected in series between the positive terminal of the battery module and ground, the second voltage divider branch being electrically connected to the microcontroller unit; and a seventh switch, electrically connected between the control terminal of the sixth switch and ground, the control terminal of the seventh switch also being electrically connected to the microcontroller unit.

[0032] In the above implementation structure, when it is necessary to detect the voltage of the battery module, the microcontroller can send a control signal to the control terminal of the seventh switch to turn on the seventh switch, thereby grounding the control terminal of the sixth switch. This causes the sixth switch to turn on under the influence of the positive voltage of the battery module, allowing the microcontroller to acquire the positive voltage of the battery module. Furthermore, under the action of the second voltage divider branch, the positive voltage of the battery module will be reduced by a set ratio, ensuring that the second detection signal received by the microcontroller is within the voltage range detectable by the microcontroller.

[0033] In one alternative embodiment of the above-described optional example, the second voltage divider branch includes at least two resistors connected in series, and the node between the series-connected resistors is electrically connected to the microcontroller unit.

[0034] In the above implementation structure, a second voltage divider branch is formed by at least two resistors connected in series, and a microcontroller is electrically connected at the node between the resistors connected in series. This enables the positive voltage of the battery module transmitted from the sixth switch to be divided according to a set ratio, so that the second detection signal received by the microcontroller is within the voltage range that the microcontroller can detect.

[0035] In another optional embodiment of the above-described optional example, the second voltage detection circuit further includes: a tenth resistor, one end of which is electrically connected to the control terminal of the sixth switch and the second terminal of the seventh switch, the other end of which is electrically connected to the first terminal of the sixth switch, and the other end of which is also configured to be electrically connected to the positive terminal of the battery module; and an eleventh resistor, one end of which is electrically connected to the first terminal of the seventh switch and ground, and the other end of which is electrically connected to the control terminal of the seventh switch and the microcontroller unit.

[0036] In the above implementation structure, the tenth resistor constitutes the bias resistor of the sixth switch, and the eleventh resistor constitutes the bias resistor of the seventh switch. Thus, the tenth resistor ensures that the sixth switch operates within the designed operating range, and the eleventh resistor ensures that the seventh switch operates within the designed operating range.

[0037] In the above optional embodiments, the second voltage detection circuit may further include: a twelfth resistor, one end of which is electrically connected to the control terminal of the sixth switch and the tenth resistor, and the other end of which is electrically connected to the second terminal of the seventh switch.

[0038] In the above implementation structure, the twelfth resistor can limit the current between the control terminal of the sixth switch and the second terminal of the seventh switch, and can also act as a voltage divider to prevent the seventh switch from being damaged due to excessive current or voltage.

[0039] In the above optional embodiments, the second voltage detection circuit may further include: a thirteenth resistor; the control terminal of the seventh switch is electrically connected to the microcontroller unit through the thirteenth resistor.

[0040] In the above implementation structure, the control terminal of the seventh switch is electrically connected to the microcontroller unit through the thirteenth resistor. When the microcontroller unit outputs a high-level control signal, the thirteenth resistor can limit the current flowing into the control terminal of the seventh switch and can also act as a voltage divider, thereby preventing the seventh switch from being damaged due to excessive current or voltage.

[0041] In a fourth alternative embodiment of the first aspect described above, the first switch includes an optocoupler or an optoMOS relay.

[0042] In the above implementation structure, the first switch is realized by optocoupler or optoMOS relay, which can effectively realize the on-off control of the circuit where the positive terminal, load and negative terminal of the battery module are located. Moreover, the device cost is low, the structure is simple, and it is easy to design the circuit.

[0043] In a fifth alternative embodiment of the first aspect described above, the battery pack parallel control device further includes: a fourteenth resistor and an eighth switch; the fourteenth resistor, the first terminal of the first switch, and the eighth switch are connected in series between the output terminal of the voltage converter and ground, and the control terminal of the eighth switch is also electrically connected to the microcontroller unit; the second terminal of the first switch is configured to be electrically connected between the positive terminal and the negative terminal of the battery module.

[0044] In the above implementation structure, the microcontroller unit can control the on / off state of the first switch by controlling the on / off state of the eighth switch, thereby achieving on / off control of the circuits containing the positive, load, and negative output terminals of the battery module. The fourteenth resistor can limit the current and voltage input to the first switch, preventing damage to the first switch due to excessive current or voltage.

[0045] In one optional example of the fifth optional embodiment described above, the battery pack parallel control device further includes: a fifteenth resistor, connected in series between the control terminal of the eighth switch and the microcontroller unit; and a sixteenth resistor, one end of which is electrically connected to both the fifteenth resistor and the control terminal of the eighth switch, and the other end of which is grounded.

[0046] In the above implementation structure, the sixteenth resistor constitutes the bias resistor of the eighth switch, ensuring that the eighth switch operates within the working area, while the fifteenth resistor can limit the magnitude of the current and voltage input to the control terminal of the eighth switch, preventing the eighth switch from being damaged and ensuring circuit safety.

[0047] A second aspect of this application also provides a battery pack parallel operation control method, applied in the microcontroller of any of the aforementioned battery pack parallel operation control devices; the method includes: in response to receiving a first detection signal, determining whether to allow the battery pack to operate in parallel based on the first detection signal.

[0048] A third aspect of this application also provides a BMS (Battery Management System), including: a battery pack parallel operation control device of any of the foregoing; further including: a charging switch and a discharging switch; wherein the charging switch and the discharging switch are configured to be connected in series between the negative terminal and the negative terminal output terminal of the battery module.

[0049] A fourth aspect of this application also provides a battery pack, including a battery module and the aforementioned BMS, wherein the battery module is electrically connected to the BMS.

[0050] A fifth aspect of this application also provides an electrical device, including an electrical main body and the aforementioned battery pack; the battery pack supplies power to the electrical main body. Attached Figure Description

[0051] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope.

[0052] Figure 1 This is a schematic diagram of a battery pack parallel operation structure provided in an embodiment of this application;

[0053] Figure 2 This is a schematic diagram of the basic structure of a battery pack parallel operation control device provided in an embodiment of this application;

[0054] Figure 3 This is a schematic diagram of the structure of a first voltage detection sub-circuit provided in an embodiment of this application;

[0055] Figure 4 A more specific structural schematic diagram of the first voltage detection sub-circuit provided in the embodiments of this application;

[0056] Figure 5 For the embodiments of this application in Figure 4 A more specific structural diagram of the first voltage detection sub-circuit is provided based on this;

[0057] Figure 6 For the embodiments of this application in Figure 4 A schematic diagram of another, more specific, first voltage detection sub-circuit is provided based on this;

[0058] Figure 7 For the embodiments of this application in Figure 3 A more specific structural diagram of the first voltage detection sub-circuit is provided based on this;

[0059] Figure 8 For the embodiments of this application in Figure 3 A schematic diagram of another, more specific, first voltage detection sub-circuit is provided based on this;

[0060] Figure 9 A schematic diagram of an optional first voltage detection sub-circuit provided in an embodiment of this application;

[0061] Figure 10 This is a schematic diagram of the structure of a second voltage detection sub-circuit provided in an embodiment of this application;

[0062] Figure 11 This application provides a schematic diagram of the structure of a specific second voltage detection sub-circuit.

[0063] Figure 12 For the embodiments of this application in Figure 11 A more specific structural diagram of a second voltage detection sub-circuit is provided based on this;

[0064] Figure 13 For the embodiments of this application in Figure 11 A schematic diagram of another, more specific, second voltage detection sub-circuit is provided based on this;

[0065] Figure 14 A schematic diagram of an optional second voltage detection sub-circuit provided in an embodiment of this application;

[0066] Figure 15 A schematic diagram of another optional second voltage detection sub-circuit provided in an embodiment of this application;

[0067] Figure 16 A flowchart illustrating a pool package parallel management method provided in an embodiment of this application;

[0068] Figure 17 This is a schematic diagram of a dual-packet parallel machine structure provided in an embodiment of this application;

[0069] Figure 18 This is a schematic diagram of the structure of a battery pack parallel operation control device provided in an embodiment of this application;

[0070] Figure 19 This is a schematic diagram of the structure of a second voltage detection circuit provided in an embodiment of this application;

[0071] Figure 20This is a schematic diagram of the structure of a specific second voltage detection circuit provided in an embodiment of this application;

[0072] Figure 21 For the embodiments of this application in Figure 20 A schematic diagram of a more specific second voltage detection circuit is provided based on the above.

[0073] Figure 22 For the embodiments of this application in Figure 20 A schematic diagram of another, more specific, second voltage detection circuit is provided based on this;

[0074] Figure 23 A schematic diagram of an optional second voltage detection sub-circuit provided in an embodiment of this application;

[0075] Figure 24 A schematic diagram of another optional second voltage detection sub-circuit provided in an embodiment of this application;

[0076] Figure 25 This is a schematic diagram of the load management circuit provided in an embodiment of this application. Detailed Implementation

[0077] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0078] 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 pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0079] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0080] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will understand that the embodiments described herein can be combined with other embodiments.

[0081] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical term "electrical connection" can refer to a direct electrical connection or an indirect electrical connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0082] Currently, rechargeable batteries are widely used in electrical equipment such as electric bicycles, electric motorcycles, drones, and electric vehicles, as well as in military equipment and aerospace. With the continuous expansion of the application areas of rechargeable batteries, the market demand is also constantly increasing.

[0083] The inventors have noted that, in order to expand capacity and improve the battery life of electrical equipment, two or more battery packs can be used in parallel. However, when battery packs are used in parallel, to avoid circulating current charging due to voltage inconsistencies or significant differences between the packs, which could cause irreversible damage to the cells, the battery packs need to communicate with each other during the parallel operation to understand each other's battery status and determine whether parallel operation is feasible. If the battery pack communication fails, reliable parallel operation management cannot be achieved.

[0084] Therefore, in this application embodiment, the inventors propose a battery pack parallel operation control device, which determines whether the battery packs can be paralleled by detecting the voltage value of the negative output terminal of the battery pack, thereby enabling reliable parallel operation management even when the battery packs cannot communicate normally.

[0085] Below, to facilitate understanding of the solutions in the embodiments of this application, some basic knowledge involved in this application will be introduced first:

[0086] See Figure 1 As shown, Figure 1 The diagram illustrates a parallel configuration of two battery packs. Both packs share the same positive output terminal P+ and negative output terminal P-, with P+ being the positive terminal and P- the negative terminal. The battery packs can be electrically connected to the load of an electrical device via the positive terminal P+ and negative terminal P- to supply power. Alternatively, the battery packs can be electrically connected to a charger via the same terminals for charging.

[0087] Each battery pack includes a battery module and a BMS (Battery Management System). B+ is the positive terminal of the battery module, and B- is the negative terminal. The BMS includes a microcontroller unit (such as an MCU, microcontroller, or microprocessor) and other circuits electrically connected to the battery module (such as data acquisition chips like AFE (Analog Front End) chips) for managing the charging and discharging of the battery module.

[0088] A battery module can be composed of multiple battery cells, which can be connected in series, parallel, or in a hybrid configuration. A hybrid configuration refers to multiple battery cells being connected in both series and parallel configurations. Multiple battery cells can be directly connected in series, parallel, or in a hybrid configuration to form a battery module. It is understood that a battery module can also be formed by first connecting multiple battery cells in series, parallel, or in a hybrid configuration to form a battery pack, and then connecting multiple battery packs in series, parallel, or in a hybrid configuration to form a whole. The battery module may also include other structures, such as busbars, for realizing electrical connections between multiple battery cells. In the embodiments of this application, the battery cell can be a secondary battery, including lithium-ion batteries, sodium-ion batteries, magnesium-ion batteries, or solid-state batteries, but is not limited to these. In the embodiments of this application, the battery cell can be a battery cell or a battery entity containing a battery cell; no limitation is made here.

[0089] See below Figure 2 As shown, Figure 2 This diagram illustrates the basic structure of the battery pack parallel operation control device provided in an embodiment of this application. The battery pack parallel operation control device can be part of a BMS (Battery Management System) and is included within the BMS, but this is not a limitation. The battery pack parallel operation control device includes: a load RS, a microcontroller unit, a first switch K1, and a first voltage detection circuit. Wherein:

[0090] The first switch K1 and the load RS are configured to be connected in series between the negative output terminal P- of the battery pack and the positive terminal B+ of the battery module in the battery pack. The first switch K1 can perform on / off operations in response to the control signal of the microcontroller unit.

[0091] A first voltage detection circuit is electrically connected to the microcontroller unit, and is also configured to be electrically connected to the negative output terminal P- to detect the voltage at the negative output terminal P- and output a first detection signal to the microcontroller unit. The first detection signal can be used to characterize the voltage at the negative output terminal P-, and the microcontroller unit is configured to determine whether parallel operation of the battery pack is permitted based on the first detection signal.

[0092] In this embodiment, the load RS can be a power-consuming device such as a resistor, but this is not a limitation. In this embodiment, the first switch K1 can be a controlled switching device such as an optocoupler, an opto-MOS relay, a MOS transistor, or a triode, but this is not a limitation either.

[0093] In this embodiment, considering that the voltage at the negative output terminal P- can be negative, the first voltage detection circuit may include a first voltage detection sub-circuit for detecting the negative voltage at the negative output terminal P-. It is understood that when the voltage at P- is negative, the voltage value is negative and less than 0 volts.

[0094] In one feasible implementation, see [link to relevant documentation]. Figure 3 As shown, the first voltage detection sub-circuit may include a second switch K2 and a third switch K3. Wherein:

[0095] The second switch K2 is electrically connected between the output of the voltage converter and the microcontroller unit.

[0096] The third switch K3 is configured to be electrically connected between the control terminal of the second switch K2 and the negative output terminal P-, and the control terminal of the third switch K3 is grounded.

[0097] Thus, when the voltage at the negative output terminal P- is negative, the third switch K3 can be opened, thereby opening the second switch K2, so that the microcontroller receives the signal output by the voltage converter and can determine that the voltage at the negative output terminal P- is negative.

[0098] In the embodiments of this application, the second switch K2 and the third switch K3 can be controlled switching devices such as optocouplers, opto-MOS relays, MOS transistors, and triodes, but this is not a limitation.

[0099] In the embodiments of this application, the voltage converter may be a DC-DC converter, an LDO (Low Dropout Regulator) regulator, a power conversion circuit or chip, etc., which can convert the voltage provided by the battery module or other power source into a set voltage value for output, such as 3.3V or 5V.

[0100] In the above feasible implementations, please continue to refer to Figure 4 As shown, the first voltage detection sub-circuit may further include: a first resistor R1 and a second resistor R2. Wherein:

[0101] One end of the first resistor R1 is electrically connected to the control terminal of the second switch K2 and the second terminal of the third switch K3, respectively. The other end of the first resistor R1 is electrically connected to the output terminal of the voltage converter and the first terminal of the second switch K2, respectively. The second terminal of the second switch K2 is electrically connected to the microcontroller unit.

[0102] The second resistor R2 has one end electrically connected to the first end of the third switch K3. One end of the second resistor R2 is also configured to be electrically connected to the negative output terminal P-. The other end of the second resistor R2 is connected to the control terminal of the third switch K3 and ground, respectively. The second end of the third switch K3 is electrically connected to the control terminal of the second switch K2.

[0103] In this way, the first resistor R1 forms the bias resistor of the second switch K2, and the second resistor R2 forms the bias resistor of the third switch K3. By reasonably setting the resistance values ​​of the first resistor R1 and the second resistor R2, it can be ensured that the second switch K2 and the third switch K3 operate within the designed operating range, thus having good controlled switching performance.

[0104] In the above feasible implementations, please continue to refer to Figure 5 As shown, the first voltage detection sub-circuit may further include a third resistor R3. One end of the third resistor R3 is electrically connected to the control terminal of the second switch K2 and the first resistor R1, and the other end of the third resistor R3 is electrically connected to the second terminal of the third switch K3. In this way, by properly setting the resistance value of the third resistor R3, the current between the control terminal of the second switch K2 and the second terminal of the third switch K3 can be limited, and it can also act as a voltage divider to prevent damage to the third switch K3 due to excessive current or voltage.

[0105] In the above feasible implementations, please continue to refer to Figure 6 As shown, the first voltage detection sub-circuit may also include a fourth resistor R4. The control terminal of the third switch K3 is grounded through the fourth resistor R4. In this way, when the voltage at the negative output terminal P- is negative, the fourth resistor R4 can limit the current flowing into the control terminal of the third switch K3 and can also act as a voltage divider, thereby preventing damage to the third switch K3 due to excessive current or voltage.

[0106] Optionally, when using both the second resistor R2 and the fourth resistor R4, such as Figure 6 As shown, the other end of the second resistor R2 can be grounded through the fourth resistor R4, so that the fourth resistor R4 can also play the role of current limiting and voltage division for the second resistor R2, which is used as a bias resistor, to avoid the bias current flowing through the second resistor R2 being too large and affecting the working performance of the third switch K3.

[0107] In the above feasible implementations, please continue to refer to Figure 7 As shown, the first voltage detection sub-circuit may further include a fifth resistor R5. One end of the fifth resistor R5 is electrically connected to both the microcontroller and the second switch K2, and the other end of the fifth resistor R5 is grounded. Thus, when the second switch K2 is open, the voltage at the microcontroller's interface can be pulled down to 0 through the fifth resistor R5, thereby preventing the microcontroller's interface from being left floating.

[0108] In the above feasible implementations, please continue to refer to Figure 8 As shown, the first voltage detection sub-circuit may further include a diode D1. The anode of diode D1 is electrically connected to the third switch K3, and the cathode of diode D1 is configured to be electrically connected to the negative output terminal P-. This design of diode D1 prevents current from flowing back into the first voltage detection sub-circuit when the voltage at the negative output terminal P- is positive, thus protecting the safety of the first voltage detection sub-circuit. Simultaneously, since diode D1 has a turn-on voltage, its design ensures that the absolute value of the negative voltage at the negative output terminal P- must exceed a certain value before the second switch K2 and the third switch K3 will conduct. This allows control over the allowable fluctuation range of the negative voltage at the negative output terminal P-, preventing the first voltage detection sub-circuit from being overly sensitive and detecting normal voltage fluctuations during use as abnormal negative voltages at the negative output terminal P- (during normal use of the battery module, the output voltage of the battery module will fluctuate to some extent; therefore, short-term, slight negative voltages at the negative output terminal P- are normal).

[0109] In the embodiments of this application, the above Figures 4 to 8 The circuit structure shown can be combined arbitrarily. For example, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the diode D1 can all be used in the first voltage detection sub-circuit. Figure 9 As shown.

[0110] Furthermore, in this embodiment, the microcontroller unit can be connected to the first voltage detection sub-circuit via, but is not limited to, an RC filter circuit, for example... Figure 9 As shown. Figure 9 The resistor Rk and capacitor Ck together form an RC filter circuit.

[0111] Understandable, Figure 9 The description is based on the case where the second switch K2 is a PNP transistor and the third switch K3 is an NPN transistor. The first terminal of the second switch K2 and the third switch K3 is the emitter, the second terminal is the collector, and the control terminal is the base. However, this is not intended to limit the embodiments of this application.

[0112] It is understood that the implementation structure of the first voltage detection sub-circuit in the above example is only a few possible first voltage detection sub-circuit structures illustrated in this application, and is not intended to limit the embodiments of this application.

[0113] In this embodiment of the application, considering that the voltage of the negative output terminal P- can also be a positive voltage, the first voltage detection circuit may further include a second voltage detection sub-circuit for detecting the positive voltage of the negative output terminal P-.

[0114] In one feasible implementation, see [link to relevant documentation]. Figure 10 As shown, the second voltage detection sub-circuit may include a fourth switch K4, a fifth switch K5, and a first voltage divider branch. Wherein:

[0115] The fourth switch K4 and the first voltage divider branch are configured to be connected in series between the negative output terminal P- and ground, and the first voltage divider branch is electrically connected to the microcontroller unit.

[0116] The fifth switch K5 is electrically connected between the control terminal of the fourth switch K4 and ground. The control terminal of the fifth switch K5 is also electrically connected to the microcontroller unit.

[0117] Thus, when detecting the voltage at the negative output terminal P-, the microcontroller only needs to send a control signal to the control terminal of the fifth switch K5 to turn on the fifth switch K5, thereby grounding the control terminal of the fourth switch K4. When the voltage at the negative output terminal P- is positive, the fourth switch K4 turns on, allowing the microcontroller to acquire the voltage at the negative output terminal P-. Simultaneously, under the action of the first voltage divider branch, the voltage at the negative output terminal P- will be reduced by a set ratio, ensuring that the first detection signal received by the microcontroller is within its detectable voltage range, preventing damage to the microcontroller due to excessive voltage.

[0118] In the embodiments of this application, the fourth switch K4 and the fifth switch K5 can be controlled switching devices such as optocouplers, opto-MOS relays, MOS transistors, and triodes, but this is not a limitation.

[0119] In this embodiment, the first voltage divider branch may include at least two resistors connected in series, with the node between the series-connected resistors electrically connected to the microcontroller unit. For example, as... Figure 10 As shown, the first voltage divider branch includes two resistors, Rd1 and Rd2, which are connected in series. The microcontroller is electrically connected between Rd1 and Rd2. Thus, through the voltage division effect of Rd1 and Rd2, the voltage received by the microcontroller can be equal to Rd2 / (Rd1+Rd2) times the voltage of the negative output terminal P-.

[0120] In the above feasible implementation, see Figure 11 As shown, the second voltage detection sub-circuit may further include a sixth resistor R6 and a seventh resistor R7. Wherein:

[0121] One end of the sixth resistor R6 is electrically connected to the control terminal of the fourth switch K4 and the second terminal of the fifth switch K5, respectively. The other end of the sixth resistor R6 is electrically connected to the first terminal of the fourth switch K4. The other end of the sixth resistor R6 is also configured to be electrically connected to the negative output terminal P-. The second terminal of the fourth switch K4 is electrically connected to the first voltage divider branch.

[0122] One end of the seventh resistor R7 is connected to the first end of the fifth switch K5 and ground, and the other end of the seventh resistor R7 is connected to the control end of the fifth switch K5 and the microcontroller unit, respectively. The second end of the fifth switch K5 is connected to the control end of the fourth switch K4.

[0123] In this way, the sixth resistor R6 forms the bias resistor of the fourth switch K4, and the seventh resistor R7 forms the bias resistor of the fifth switch K5. By reasonably setting the resistance values ​​of the sixth resistor R6 and the seventh resistor R7, it can be ensured that the fourth switch K4 and the fifth switch K5 operate within the designed operating range, thus having good controlled switching performance.

[0124] In the above feasible implementation, see Figure 12 As shown, the second voltage detection sub-circuit may further include an eighth resistor. One end of the eighth resistor R8 is electrically connected to the control terminal of the fourth switch K4 and the sixth resistor R6, respectively, and the other end of the eighth resistor R8 is electrically connected to the second terminal of the fifth switch K5. In this way, by properly setting the resistance value of the eighth resistor R8, the current between the control terminal of the fourth switch K4 and the second terminal of the fifth switch K5 can be limited, and it can also act as a voltage divider to prevent damage to the fifth switch K5 due to excessive current or voltage.

[0125] In the above feasible implementations, please continue to refer to Figure 13 As shown, the second voltage detection sub-circuit may also include a ninth resistor R9. The control terminal of the fifth switch K5 is electrically connected to the microcontroller unit through the ninth resistor R9. Thus, when the microcontroller unit outputs a high-level control signal, the ninth resistor R9 can limit the current flowing into the control terminal of the fifth switch K5 and can also act as a voltage divider, thereby preventing damage to the fifth switch K5 due to excessive current or voltage.

[0126] Optionally, when using both the seventh resistor R7 and the ninth resistor R9, such as Figure 13 As shown, the other end of the seventh resistor R7 can be electrically connected to the microcontroller unit through the ninth resistor R9, so that the ninth resistor R9 can also play the role of current limiting and voltage division for the seventh resistor R7, which is used as a bias resistor, to avoid the bias current flowing through the seventh resistor R7 being too large and affecting the working performance of the fifth switch K5.

[0127] In the embodiments of this application, the above Figures 11 to 13 The circuit structure shown can be combined arbitrarily. For example, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, and the ninth resistor R9 can all be used in the first voltage detection sub-circuit simultaneously. Figure 14 As shown. It is understandable that... Figure 14The description is based on the case where the fourth switch K4 is a PNP transistor and the fifth switch K5 is an NPN transistor. The first terminal of the second switch K2 and the third switch K3 is the emitter, the second terminal is the collector, and the control terminal is the base. However, this is not intended to limit the embodiments of this application.

[0128] Furthermore, in this embodiment, the microcontroller unit can be connected to the first voltage detection sub-circuit via, but is not limited to, an RC filter circuit, for example... Figure 14 As shown. Figure 14 The resistor Rk and capacitor Ck together form an RC filter circuit.

[0129] It is understood that the above are merely examples of some possible second voltage detection sub-circuit structures for this application and are not intended to limit the embodiments of this application. In fact, any circuit capable of detecting the specific value of the positive voltage at the negative output terminal P- can be used in this application. For example, the second voltage detection sub-circuit can also be directly constructed using a controlled switch and a first voltage divider branch, for example... Figure 15 As shown, one end of the second voltage detection sub-circuit is electrically connected to the negative output terminal P-, and the node between the two resistors in the first voltage divider branch is electrically connected to the microcontroller unit.

[0130] Based on the above-mentioned battery pack parallel control device, this application embodiment also provides a battery pack parallel control method, and the microcontroller unit can implement specific battery pack parallel control based on the method.

[0131] See also Figure 16 As shown, the method includes:

[0132] S1601: Upon receiving the first detection signal, determine whether parallel operation of the battery pack is permitted based on the first detection signal.

[0133] Understandably, see Figure 17 The diagram shows a dual-pack parallel operation. Taking B- of battery pack A on the left as the 0V potential reference point, and assuming the microcontroller unit in battery pack A needs to determine whether the charging switch Kc and / or the discharging switch Kd can be closed, the following situations apply:

[0134] a. Assume that the charging switch Kc and the discharging switch Kd of battery pack B are both open. At this time, the first switch K1 in battery pack A is closed. Regardless of the voltage of battery pack B, V_(P+_P-) is equal to the voltage of battery pack A, and V_P- is equal to 0. The charging switch Kc and the discharging switch Kd of battery pack A can be closed normally to realize the parallel operation of the battery packs.

[0135] Where V_(P+_P-) refers to the potential difference between P+ and P-, and V_P- refers to the potential value at P-.

[0136] It is understandable that case a also applies when there is no battery pack B that can be paralleled.

[0137] b. Assuming that the charging switch Kc and / or discharging switch Kd of battery pack B on the right are closed, battery pack A needs to determine whether battery pack A and battery pack B can be used in parallel.

[0138] At this time, the first switch K1 in battery pack A is closed, making the circuit containing B+, load RS, and P- in battery pack A conductive. Since B+ of both battery pack A and battery pack B are connected to P+, and P- is connected to B- of battery pack B, the positive potential of battery pack A is equal to the positive potential of battery pack B, and the potential values ​​of B- and P- of battery pack B are equal. Therefore, V_P- is equal to the voltage of battery pack A minus the voltage of battery pack B. The following situation applies:

[0139] If the voltage of battery pack B is equal to the voltage of battery pack A, then V_(P+_P-) is equal to the voltage of battery pack A, and V_P- is equal to 0. This allows the charging switch Kc and discharging switch Kd of battery pack A to be closed normally, thus enabling the battery packs to operate in parallel.

[0140] If the voltage of battery pack B is greater than the voltage of battery pack A, for example, assuming battery pack A has a voltage of 40V and battery pack B has a voltage of 60V, then V_P- = voltage of battery pack A - voltage of battery pack B = 40V - 60V = -20V, and V_(P+_P-) equals 60V. In this case, the voltage difference between battery pack A and battery pack B is large, and battery pack B is in a charging or discharging state. Therefore, battery pack A and battery pack B cannot be connected in parallel. The charging switch Kc and / or discharging switch Kd of battery pack A should be kept closed to avoid parallel operation of the battery packs.

[0141] If the voltage of battery pack B is less than the voltage of battery pack A, for example, assuming battery pack A has a voltage of 60V and battery pack B has a voltage of 40V, then V_P- = battery pack A voltage - battery pack B voltage = 60V - 40V = 20V, and V_(P+_P-) equals 40V. In this case, the voltage difference between battery pack A and battery pack B is large, and battery pack B is in a charging or discharging state. Therefore, battery pack A and battery pack B cannot be connected in parallel. The charging switch Kc and / or discharging switch Kd of battery pack A should be kept closed to avoid parallel operation of the battery packs.

[0142] Based on the above analysis, it can be seen that V_P- can be used to determine whether battery pack A can be paralleled with battery pack B, that is, whether the charging switch Kc and / or discharging switch Kd of battery pack A are allowed to be closed.

[0143] Therefore, in this embodiment, when the first detection signal is a signal transmitted by the first voltage detection sub-circuit indicating that the voltage of the negative output terminal P- is negative, the microcontroller unit can determine that the battery pack it is in should be prohibited from parallel operation, and thus does not send control signals to the charging switch Kc and the discharging switch Kd to instruct them to perform a closing operation.

[0144] When the first detection signal is a signal from the second voltage detection sub-circuit indicating that the voltage at the negative output terminal P- is positive, the voltage value at the negative output terminal P- can be reconstructed based on the first detection signal. Then, it is determined whether the value is within the allowable voltage range. If it is within the allowable voltage range, a control signal instructing the charging switch Kc and / or the discharging switch Kd to perform a closing operation is sent. If it is not within the allowable voltage range, the microcontroller unit may not send a control signal instructing the charging switch Kc and the discharging switch Kd to perform a closing operation.

[0145] It is understandable that the allowable voltage range can be determined based on the circulating current resistance of the cells in the battery pack, as long as parallel operation within this voltage range will not cause damage to the cells.

[0146] It is understandable that, when the voltage at the negative output terminal P- is negative, by selecting the second switch K2, the third switch K3, and the diode D1 with appropriate turn-on voltages, the sensitivity of the first voltage detection sub-circuit can be controlled, so that within the allowable voltage range, the first voltage detection sub-circuit will not output the first detection signal.

[0147] For example, by selecting appropriate second switch K2, third switch K3, and diode D1, since there will be voltage drops in all three switches, this will result in a negative voltage difference between battery pack A and battery pack B (i.e., P- is a negative voltage). As long as the absolute value of the negative voltage is less than or equal to the total voltage drop generated by the second switch K2, third switch K3, and diode D1, parallel operation of battery pack A and battery pack B can be achieved. For example, assuming the total voltage drop generated by the second switch K2, third switch K3, and diode D1 is 1V, then as long as the negative voltage value is between [-1V, 0], parallel operation of battery pack A and battery pack B can also be achieved.

[0148] Optionally, in the embodiments of this application, the above-described battery pack parallel operation control method can be used in conjunction with existing schemes based on communication between battery packs. For example, the battery pack parallel operation control method of this application can be used to manage situations where communication between battery packs is poor, while existing methods can be used directly when communication between battery packs is good.

[0149] It is also understandable that, based on the aforementioned analysis, in addition to direct parallel control based on the voltage of the negative output terminal P-, the charging switch Kc and / or discharging switch Kd of the battery pack can be determined together with V_(P+_P-) and the voltage of the battery pack itself to determine whether the charging switch Kc and / or discharging switch Kd of the battery pack are allowed to close.

[0150] Therefore, in the embodiments of this application, such as Figure 18 As shown, the battery pack parallel control device may further include a second voltage detection circuit. The second voltage detection circuit is electrically connected to the microcontroller unit and is also configured to be electrically connected to the positive terminal B+ of the battery module to detect the voltage of the positive terminal B+ of the battery module and output a second detection signal to the microcontroller unit. The second detection signal is used to characterize the voltage of the positive terminal B+ of the battery module.

[0151] In one feasible embodiment, the implementation structure of the second voltage detection circuit can be found in [reference needed]. Figure 19 As shown, the second voltage detection circuit may include a sixth switch K6, a seventh switch K7, and a second voltage divider branch. Wherein:

[0152] The sixth switch K6 and the second voltage divider branch are configured to be connected in series between the positive terminal B+ of the battery module and ground, and the second voltage divider branch is electrically connected to the microcontroller unit.

[0153] The seventh switch K7 is electrically connected between the control terminal of the sixth switch K6 and ground. The control terminal of the seventh switch K7 is also electrically connected to the microcontroller unit.

[0154] In this way, when detecting the voltage of the positive terminal of the battery module, the microcontroller only needs to send a control signal to the control terminal of the seventh switch K7 to turn on the seventh switch K7, thereby grounding the control terminal of the sixth switch K6, and turning on the sixth switch K6. This allows the microcontroller to collect the voltage of the positive terminal B+ of the battery module. At the same time, under the action of the second voltage divider branch, the voltage of the positive terminal B+ of the battery module will be reduced by a set ratio, so that the second detection signal received by the microcontroller is within the voltage range that the microcontroller can detect, avoiding damage to the microcontroller due to excessive voltage.

[0155] In the embodiments of this application, the sixth switch K6 and the seventh switch K7 can be controlled switching devices such as optocouplers, opto-MOS relays, MOS transistors, and triodes, but this is not a limitation.

[0156] Optionally, the second voltage divider branch may include at least two resistors connected in series, with the node between the series-connected resistors electrically connected to the microcontroller unit. For example, as shown... Figure 19As shown, the second voltage divider branch includes two resistors, Rd3 and Rd4, which are connected in series. The microcontroller is electrically connected between Rd3 and Rd4. Thus, through the voltage division effect of Rd3 and Rd4, the voltage received by the microcontroller can be equal to Rd4 / (Rd3+Rd4) times the voltage of the positive terminal B+ of the battery module.

[0157] In the above feasible implementation, see Figure 20 As shown, the second voltage detection circuit may further include a tenth resistor R10 and an eleventh resistor R11. Wherein:

[0158] One end of the tenth resistor R10 is electrically connected to the control terminal of the sixth switch K6 and the second terminal of the seventh switch K7, respectively. The other end of the tenth resistor R10 is electrically connected to the first terminal of the sixth switch K6. The other end of the tenth resistor R10 is also configured to be electrically connected to the positive terminal B+ of the battery module. The second terminal of the sixth switch K6 is electrically connected to the second voltage divider branch.

[0159] One end of the eleventh resistor R11 is connected to the first terminal of the seventh switch K7 and ground, respectively, and the other end of the eleventh resistor R11 is connected to the control terminal of the seventh switch K7 and the microcontroller unit, respectively.

[0160] In this way, the tenth resistor R10 forms the bias resistor of the sixth switch K6, and the eleventh resistor R11 forms the bias resistor of the seventh switch K7. By reasonably setting the resistance values ​​of the tenth resistor R10 and the eleventh resistor R11, it can be ensured that the sixth switch K6 and the seventh switch K7 operate within the designed operating range, thus having good controlled switching performance.

[0161] In the above feasible implementation, see Figure 21 As shown, the second voltage detection circuit may further include a twelfth resistor R12. One end of the twelfth resistor R12 is electrically connected to the control terminal of the sixth switch K6 and the tenth resistor, respectively, and the other end of the twelfth resistor R12 is electrically connected to the second terminal of the seventh switch K7. In this way, by properly setting the resistance value of the twelfth resistor R12, the current between the control terminal of the sixth switch K6 and the second terminal of the seventh switch K7 can be limited, and it can also act as a voltage divider to prevent damage to the seventh switch K7 due to excessive current or voltage.

[0162] In the above feasible implementations, please continue to refer to Figure 22 As shown, the second voltage detection circuit may further include a thirteenth resistor R13. The control terminal of the seventh switch K7 is electrically connected to the microcontroller unit through the thirteenth resistor R13. Thus, when the microcontroller unit outputs a high-level control signal, the thirteenth resistor R13 can limit the current flowing into the control terminal of the seventh switch K7 and can also act as a voltage divider, thereby preventing damage to the seventh switch K7 due to excessive current or voltage.

[0163] Optionally, when using both the eleventh resistor and the thirteenth resistor R13, such as Figure 23 As shown, the other end of the eleventh resistor can be electrically connected to the microcontroller unit through the thirteenth resistor R13, so that the thirteenth resistor R13 can also play the role of current limiting and voltage division for the eleventh resistor, which is used as a bias resistor, to avoid the bias current flowing through the eleventh resistor being too large and affecting the working performance of the seventh switch K7.

[0164] In the embodiments of this application, the above Figures 20 to 22 The circuit structure shown can be combined arbitrarily. For example, the tenth resistor, the eleventh resistor, the twelfth resistor R12, and the thirteenth resistor R13 can all be used simultaneously in the second voltage detection circuit. Figure 23 As shown. It is understandable that... Figure 23 The description is based on the case where the sixth switch K6 is a PNP transistor and the seventh switch K7 is an NPN transistor. The first terminal of the second switch K2 and the third switch K3 is the emitter, the second terminal is the collector, and the control terminal is the base. However, this is not intended to limit the embodiments of this application.

[0165] Furthermore, in this embodiment, the microcontroller unit can be connected to the first voltage detection sub-circuit via, but is not limited to, an RC filter circuit, for example... Figure 23 As shown. Figure 23 The resistor Rk and capacitor Ck together form an RC filter circuit.

[0166] It is understood that the above are merely examples of some possible second voltage detection circuit structures exemplified in this application, and are not intended to limit the embodiments of this application. In fact, any circuit capable of detecting the specific value of the positive voltage at the positive electrode B+ of the battery module can be used in this application. For example, the second voltage detection circuit can also be directly constructed using a controlled switch and a second voltage divider branch, for example... Figure 24 As shown, one end of the second voltage detection circuit is electrically connected to the positive terminal B+ of the battery module, and the node between the two resistors in the second voltage divider branch is electrically connected to the microcontroller unit.

[0167] Based on the aforementioned battery pack parallel operation control device, the microcontroller unit can determine whether parallel operation of the battery pack is allowed based on V_(P+_P-) and the voltage of the battery pack itself.

[0168] For example, in the process of determining whether to allow the battery pack to be connected in parallel, the microcontroller unit can determine whether to output a control signal indicating closure to the charging switch Kc and / or to the discharging switch Kd based on the first detection signal detected by the first voltage detection circuit and the second detection signal detected by the second voltage detection circuit.

[0169] Specifically, when the first detection signal is a signal from the first voltage detection sub-circuit indicating that the voltage at the negative output terminal P- is negative, the microcontroller determines that the battery pack is not allowed to operate in parallel, and does not send a control signal indicating closure to the charging switch Kc, nor does it send a control signal indicating closure to the discharging switch Kd.

[0170] When the first detection signal is a signal from the second voltage detection sub-circuit indicating that the voltage at the negative output terminal P- is positive, the microcontroller can reconstruct the voltage value of the negative output terminal P- based on the first detection signal, and reconstruct the voltage value of the positive terminal B+ of the battery module (i.e., the voltage of the battery module) based on the second detection signal. Then, it calculates V_(P+_P-), and then calculates the difference between V_(P+_P-) and the voltage value of the positive terminal B+ of the battery module, thereby determining whether the difference exceeds the allowable voltage range.

[0171] If the limit is exceeded, the microcontroller determines that parallel operation of the battery pack is not allowed, and does not send a control signal indicating closure to the charging switch Kc or the discharging switch Kd. If the limit is not exceeded, the microcontroller determines that parallel operation of the battery pack is allowed, and sends control signals indicating closure to the charging switch Kc and / or the discharging switch Kd of the battery pack.

[0172] It is understandable that the current diagrams show a series connection between the charging switch Kc and the discharging switch Kd in the battery pack. If parallel operation is possible, control signals indicating closure need to be sent to both the charging switch Kc and the discharging switch Kd. Alternatively, if the charging switch Kc and the discharging switch Kd in the battery pack are connected in parallel, assuming parallel operation is possible, a control signal indicating closure can be sent to the charging switch Kc during charging and to the discharging switch Kd during discharging.

[0173] In an optional embodiment of this application, to control the first switch K1, a load management circuit may also be provided in the battery pack parallel operation control device, for example... Figure 25 As shown, the load management circuit may include a fourteenth resistor R14 and an eighth switch K8. Wherein:

[0174] The fourteenth resistor R14, the first terminal of the first switch K1, and the eighth switch K8 are connected in series between the output terminal of the voltage converter and ground. The control terminal of the eighth switch K8 is also electrically connected to the microcontroller unit. The second terminal of the first switch K1 is configured to be electrically connected between the positive terminal B+ and the negative output terminal P- of the battery module.

[0175] In this way, the microcontroller unit can control the on / off state of the first switch K1 by controlling the opening and closing of the eighth switch K8, thereby achieving on / off control of the circuit containing the positive terminal B+, load RS, and negative output terminal P- of the battery module. Meanwhile, the fourteenth resistor R14 limits the current and voltage input to the first switch K1, preventing the first switch K1 from being damaged due to excessive current or voltage.

[0176] See also Figure 25 As shown in the embodiment of this application, the load management circuit may further include a fifteenth resistor R15 and a sixteenth resistor R16. The fifteenth resistor R15 is connected in series between the control terminal of the eighth switch K8 and the microcontroller unit. One end of the sixteenth resistor R16 is electrically connected to both the fifteenth resistor R15 and the control terminal of the eighth switch K8, and the other end of the sixteenth resistor R16 is grounded. In this way, the sixteenth resistor R16 constitutes the bias resistor of the eighth switch K8. By properly setting the resistance value of the sixteenth resistor R16, it can be ensured that the eighth switch K8 operates within the operating range, while the fifteenth resistor R15 can limit the magnitude of the current and voltage input to the control terminal of the eighth switch K8, preventing damage to the eighth switch K8 and ensuring circuit safety.

[0177] Understandable, Figure 25 In the example, the first switch K1 is an optocoupler, but this is not a limitation of the embodiments of this application. As mentioned above, the first switch K1 can also be a controlled switching device such as an opto-MOS relay, a MOS transistor, or a triode. Furthermore, Figure 25 The eighth switch K8 in the example is a MOS transistor, but it is not intended to limit the embodiments of this application. The eighth switch K8 can also be implemented using controlled switching devices such as optocouplers, opto-MOS relays, and transistors.

[0178] It is also understood that the above is merely an example of the structure of the battery pack parallel control device in the embodiments of this application, and is not intended to limit the specific battery pack parallel control device. Based on the battery pack parallel control device provided in the embodiments of this application, the battery status between battery packs can be determined based on the detected voltage value of the negative output terminal P-, or by combining the detected voltage value of the negative output terminal P- with the detected voltage value of the positive terminal B+ of the battery module, thereby determining whether the battery packs can be paralleled. This enables reliable parallel management even when two or more battery packs cannot communicate normally during parallel operation.

[0179] Based on the same inventive concept, this application also provides a BMS, which includes the battery pack parallel control device provided in this application embodiment, and further includes a charging switch Kc and a discharging switch Kd, wherein the charging switch Kc and the discharging switch Kd are configured to be connected in series between the negative terminal and the negative output terminal P- of the battery module. The charging switch Kc and the discharging switch Kd can be turned on and off under the control of the microcontroller unit to realize the charging or discharging control of the battery module.

[0180] Based on the same inventive concept, this application also provides a battery pack, including a battery module and a BMS provided in this application embodiment, wherein the battery module is electrically connected to the BMS.

[0181] Based on the same inventive concept, this application also provides an electrical device, including an electrical main body and the battery pack provided above, wherein the battery pack supplies power to the electrical main body.

[0182] The electrical devices provided in this application embodiment can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, drones, electric two-wheeled vehicles (such as electric cars, electric bicycles, etc.), electric motorcycles, electric tricycles, electric cars, ships, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.

[0183] The embodiments described above are merely illustrative and only examples of this application. They are not intended to limit the scope of protection of this application. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A battery pack parallel operation control device, characterized in that, include: Load and microcontroller unit; A first switch is configured to be connected in series with the load between the negative output terminal of the battery pack and the positive terminal of the battery module in the battery pack; wherein the first switch is capable of performing on / off operations in response to the control signal of the microcontroller unit; A first voltage detection circuit is electrically connected to the microcontroller unit. The first voltage detection circuit is also configured to be electrically connected to the negative output terminal to detect the voltage of the negative output terminal and output a first detection signal to the microcontroller unit. The first detection signal is used to characterize the voltage of the negative output terminal. The microcontroller unit is configured to determine whether to allow the battery pack to operate in parallel based on the first detection signal.

2. The battery pack parallel operation control device as described in claim 1, characterized in that, The first voltage detection circuit includes a first voltage detection sub-circuit, which includes: The second switch is electrically connected between the output terminal of the voltage converter and the microcontroller unit. The third switch is configured to be electrically connected between the control terminal of the second switch and the negative output terminal, and the control terminal of the third switch is grounded.

3. The battery pack parallel operation control device as described in claim 2, characterized in that, The first voltage detection sub-circuit further includes: A first resistor, one end of which is electrically connected to the control terminal of the second switch and the second terminal of the third switch, and the other end of which is electrically connected to the output terminal of the voltage converter and the first terminal of the second switch, and the second terminal of the second switch is electrically connected to the microcontroller unit. The second resistor has one end electrically connected to the first end of the third switch and another end configured to be electrically connected to the negative output terminal. The other end of the second resistor is electrically connected to the control terminal of the third switch and ground, respectively. The second end of the third switch is electrically connected to the control terminal of the second switch.

4. The battery pack parallel operation control device as described in claim 3, characterized in that, The first voltage detection sub-circuit further includes: The third resistor has one end electrically connected to the control terminal of the second switch and the first resistor, and the other end electrically connected to the second terminal of the third switch.

5. The battery pack parallel operation control device as described in claim 3, characterized in that, The first voltage detection sub-circuit further includes: The fourth resistor; the control terminal of the third switch is grounded through the fourth resistor.

6. The battery pack parallel operation control device as described in claim 2, characterized in that, The first voltage detection sub-circuit further includes: The fifth resistor has one end electrically connected to the microcontroller unit and the second switch, and the other end grounded.

7. The battery pack parallel operation control device as described in claim 2, characterized in that, The first voltage detection sub-circuit further includes: The diode has its positive terminal electrically connected to the third switch, and its negative terminal configured to be electrically connected to the negative output terminal.

8. The battery pack parallel operation control device as described in claim 1, characterized in that, The first voltage detection circuit includes a second voltage detection sub-circuit; The second voltage detection sub-circuit includes: The fourth switch and the first voltage divider branch are configured to be connected in series between the negative output terminal and ground, and the first voltage divider branch is electrically connected to the microcontroller unit. The fifth switch is electrically connected between the control terminal of the fourth switch and ground, and the control terminal of the fifth switch is also electrically connected to the microcontroller unit.

9. The battery pack parallel operation control device as described in claim 8, characterized in that, The first voltage divider branch includes at least two resistors connected in series, and the node between the series resistors is electrically connected to the microcontroller unit.

10. The battery pack parallel operation control device as described in claim 8, characterized in that, The second voltage detection sub-circuit also includes: The sixth resistor has one end electrically connected to the control terminal of the fourth switch and the second terminal of the fifth switch, and the other end electrically connected to the first terminal of the fourth switch. The other end of the sixth resistor is also configured to be electrically connected to the negative output terminal. The second terminal of the fourth switch is electrically connected to the first voltage divider branch. The seventh resistor has one end connected to the first terminal of the fifth switch and ground, and the other end connected to the control terminal of the fifth switch and the microcontroller unit. The second terminal of the fifth switch is connected to the control terminal of the fourth switch.

11. The battery pack parallel operation control device as described in claim 10, characterized in that, The second voltage detection sub-circuit also includes: The eighth resistor has one end electrically connected to the control terminal of the fourth switch and the sixth resistor, and the other end electrically connected to the second terminal of the fifth switch.

12. The battery pack parallel operation control device as described in claim 10, characterized in that, The second voltage detection sub-circuit also includes: The ninth resistor; the control terminal of the fifth switch is electrically connected to the microcontroller unit through the ninth resistor.

13. The battery pack parallel operation control device as described in any one of claims 1-12, characterized in that, The battery pack parallel control device also includes: A second voltage detection circuit is electrically connected to the microcontroller unit. The second voltage detection circuit is also configured to be electrically connected to the positive terminal of the battery module to detect the voltage of the positive terminal of the battery module and output a second detection signal to the microcontroller unit. The second detection signal is used to characterize the voltage of the positive terminal of the battery module.

14. The battery pack parallel operation control device as described in claim 13, characterized in that, The second voltage detection circuit includes: A sixth switch and a second voltage divider branch are configured to be connected in series between the positive terminal and ground of the battery module, and the second voltage divider branch is electrically connected to the microcontroller unit. The seventh switch is electrically connected between the control terminal of the sixth switch and ground, and the control terminal of the seventh switch is also electrically connected to the microcontroller unit.

15. The battery pack parallel operation control device as described in claim 14, characterized in that, The second voltage divider branch includes at least two resistors connected in series, and the node between the series resistors is electrically connected to the microcontroller unit.

16. The battery pack parallel operation control device as described in claim 14, characterized in that, The second voltage detection circuit also includes: The tenth resistor has one end electrically connected to the control terminal of the sixth switch and the second terminal of the seventh switch, and the other end electrically connected to the first terminal of the sixth switch. The other end of the tenth resistor is also configured to be electrically connected to the positive terminal of the battery module. The eleventh resistor has one end connected to the first terminal of the seventh switch and ground, and the other end connected to the control terminal of the seventh switch and the microcontroller unit.

17. The battery pack parallel operation control device as described in claim 16, characterized in that, The second voltage detection circuit also includes: The twelfth resistor has one end electrically connected to the control terminal of the sixth switch and the tenth resistor, and the other end electrically connected to the second terminal of the seventh switch.

18. The battery pack parallel operation control device as described in claim 16, characterized in that, The second voltage detection circuit further includes a thirteenth resistor; the control terminal of the seventh switch is electrically connected to the microcontroller unit through the thirteenth resistor.

19. The battery pack parallel operation control device as described in any one of claims 1-12, characterized in that, The first switch includes an optocoupler or an optoMOS relay.

20. The battery pack parallel operation control device according to any one of claims 1-12, characterized in that, The battery pack parallel control device also includes: a fourteenth resistor and an eighth switch; The fourteenth resistor, the first terminal of the first switch, and the eighth switch are connected in series between the output terminal of the voltage converter and ground. The control terminal of the eighth switch is also electrically connected to the microcontroller unit. The second terminal of the first switch is configured to be electrically connected between the positive terminal and the negative terminal of the battery module.

21. The battery pack parallel operation control device as described in claim 20, characterized in that, The battery pack parallel control device also includes: The fifteenth resistor is connected in series between the control terminal of the eighth switch and the microcontroller unit. The sixteenth resistor has one end electrically connected to the control terminals of the fifteenth resistor and the eighth switch, and the other end grounded.

22. A method for parallel control of a battery pack, characterized in that, The method is applied in a microcontroller of a battery pack parallel operation control device as described in any one of claims 1-21; the method includes: In response to receiving the first detection signal, determine whether to allow the battery pack to operate in parallel based on the first detection signal.

23. A battery management system, characterized in that, include: The battery pack parallel operation control device as described in any one of claims 1-21 further includes: a charging switch and a discharging switch; The charging switch and the discharging switch are configured to be connected in series between the negative terminal and the negative output terminal of the battery module.

24. A battery pack, characterized in that, It includes a battery module and a battery management system as described in claim 23, wherein the battery module is electrically connected to the battery management system.

25. An electrical appliance, characterized in that, It includes a power-consuming body and a battery pack as described in claim 24; the battery pack supplies power to the power-consuming body.

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