A control circuit and method for a multi-battery pack BMS system and multiple parallel battery packs

Abstract

The present application relates to the technical field of parallel control of multiple battery packs, and more specifically, to a control circuit, method, and multiple parallel battery packs for a multiple battery pack BMS system. The system comprises a main control module and several battery pack modules; each of the battery pack modules is provided with several battery cells, a first switch module, a second switch module, and a first control module for connection to the main control module for charging and discharging. The present application implements charge and discharge control between multiple battery pack modules, reducing the control load of the main control module, thereby reducing the control load of the BMS system. It also enables charge and discharge control between multiple battery pack modules without distinguishing between primary and secondary battery packs, greatly reducing the cost of hardware design.

Description

Technical Field

[0001] The present application relates to the technical field of parallel control of multiple battery packs, and more specifically, to a control circuit and method of a multiple battery pack BMS system and multiple parallel battery packs. Background Art

[0002] With the development of robotics applications, the market demand for battery packs with long battery life and high discharge current is increasing. Generally, the battery life and discharge current of a single battery pack are relatively small. If a battery pack with long battery life and high discharge current is required, the main way to increase the battery life and discharge current is to directly increase the number of battery packs in parallel.

[0003] As the number of battery packs increases, the control difficulty of the BMS system (battery management system) also increases. In the existing technology, when the discharge output positive and negative terminals and charging input positive and negative terminals of multiple battery packs are connected in parallel to the main control board, the battery pack power information is mainly obtained through communication between the main control board and the battery pack, and then the charging and discharging MOS tubes on the main board are controlled. The number of MOS tubes is determined by the current size of the loop. When the current is large, more MOS tubes are required. This control method not only increases the hardware design cost in the production process, but also increases the load of the main control board, thereby increasing the control load of the BMS system.

[0004] In addition, it is necessary to distinguish between the main and auxiliary battery packs among multiple battery pack modules. That is, in the actual production process, the matching main and auxiliary packs need to be produced at the same time before they can be used, which greatly increases the hardware design cost in the production process. Summary of the Invention

[0005] In order to solve the technical problem described in the background technology that multiple battery packs need to be controlled by distinguishing between main and sub battery packs during charging and discharging, and the main control module has a high load, the present application provides a control circuit, method and multiple parallel battery packs for a multi-battery pack BMS system.

[0006] In a first aspect, the present application provides a control circuit for a multi-battery pack BMS system, comprising:

[0007] Main control module, used to control the usage status of the battery pack;

[0008] A plurality of battery pack modules, each of which is provided with a plurality of battery cells, a first switch module, a second switch module and a first control module, and is used for connecting to the main control module for charging and discharging;

[0009] In which, the battery cell is connected to the main control module to form a loop; the first port of the first switch module is connected to the positive electrode of the battery cell, and the second port is connected to the positive port of the main control module; the second switch module includes a first MOS tube for external output protection of the battery pack module, a first diode for blocking the charging current between each battery pack module and a first thermistor for limiting the external output current, the source of the first MOS tube is connected to the third port of the first switch module, and the drain is connected to the anode of the first diode through the first thermistor; the cathode of the first diode is connected to the second port of the first switch module; the first control module is communicatively connected to the main control module, the first control end is connected to the control end of the first switch module, and the second control end is connected to the gate of the first MOS tube.

[0010] In some preferred embodiments, the circuit further includes a first resistor connected between the negative electrode of the battery cell and the negative port of the main control module.

[0011] In some preferred embodiments, the first control module includes a first chip for controlling the first switch module and a second chip for controlling the second switch module, the first signal end of the first chip is connected to the second port of the first switch module, the second signal end and the third signal end of the first chip are connected in parallel to the two ends of the first resistor, the data end is connected to the first communication end of the second chip, and the output end group is connected to the control end of the first switch module; the second communication end of the second chip is connected to the communication port of the main control module, the identification end is connected to the identification port of the main control module, and the output end is connected to the gate of the first MOS tube.

[0012] In some preferred embodiments, the first switch module includes a second MOS transistor and a third MOS transistor, the gate of the second MOS transistor is connected to the first output end of the first chip, the source is connected to the positive electrode of the battery cell, and the drain is connected to the drain of the third MOS transistor; the gate of the third MOS transistor is connected to the second output end of the first chip, and the source is connected to the positive port of the main control module; the source of the first MOS transistor is connected to the drain of the second MOS transistor.

[0013] In some preferred embodiments, the first switch module is provided with a plurality of the second MOS transistors and a plurality of the third MOS transistors, the sources of the second MOS transistors are connected in parallel, the gates are connected in parallel, and the drains are connected in parallel; the sources of the third MOS transistors are connected in parallel, the gates are connected in parallel, and the drains are connected in parallel.

[0014] In some preferred embodiments, the first MOS transistor is a P-channel MOS transistor; the second MOS transistor and the third MOS transistor are both N-channel MOS transistors; the first chip is a chip with a high-end drive function; and the second chip is a chip with a communication function.

[0015] In some preferred embodiments, the circuit further includes a first fuse connected between the positive electrode of the battery cell and the source electrode of the second MOS transistor Q2.

[0016] In a second aspect, the present application provides a control method for a multi-battery pack BMS system, the method being applied to the control circuit of the multi-battery pack BMS system as described in the first aspect, the method comprising:

[0017] A power supply circuit is formed between the battery cell and the main control module;

[0018] The first switch module controls the conduction between the battery cell and the main control module;

[0019] The second switch module is connected in parallel between the second port and the third port of the first switch module, and limits the charging current between the battery pack modules and protects the external output;

[0020] The first control module is in communication with the main control module and controls the conduction of the first switch module and the second switch module respectively according to the working status of each battery pack module in the loop.

[0021] In some preferred embodiments, the second switch module includes a first MOS tube for external output protection of the battery pack module, a first diode for blocking the charging current between the battery pack modules, and a first thermistor for limiting the external output current;

[0022] The source of the first MOS transistor is connected to the third port of the first switch module, and the drain is connected to the anode of the first diode through the first thermistor; the cathode of the first diode is connected to the second port of the first switch module.

[0023] In a third aspect, the present application provides a multi-parallel battery pack, including a control circuit of the multi-battery pack BMS system as described in the first aspect.

[0024] The beneficial effects are:

[0025] 1. This application establishes a communication connection with the main control module through a first control module, and then the first control module controls the conduction of the first switch module and the second switch module respectively according to the communication signal of the main control module to realize the charge and discharge control between multiple battery pack modules, thereby reducing the control load of the main control module and thus reducing the control load of the BMS system.

[0026] 2. This application uses a second switch module to limit the charging current between multiple battery pack modules and protect the external output, thereby achieving the effect of controlling charging and discharging between multiple battery pack modules without distinguishing between the main and auxiliary battery packs, greatly reducing the cost of hardware design. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the structure of the control circuit of the multi-battery pack BMS system provided in an embodiment of the present application.

[0028] Figure 2 This is a circuit module diagram of the control circuit of the multi-battery pack BMS system provided in an embodiment of the present application.

[0029] Figure 3 This is a circuit diagram of the control circuit of the multi-battery pack BMS system provided in an embodiment of the present application.

[0030] Figure 4 1 is a circuit diagram of the first switch module provided in an embodiment of the present application.

[0031] Figure 5 This is a flowchart of the implementation of the control method of the multi-battery pack BMS system provided in an embodiment of the present application.

[0032] Figure 6 A schematic diagram of the structure of a multi-parallel battery pack provided in an embodiment of the present application.

[0033] Wherein: 10-first battery pack module, R1-first resistor, F1-first fuse;

[0034] 11-first switch module, Q2-second MOS tube, Q3-third MOS tube;

[0035] 12-second switch module, Q1-first MOS tube, PTC1-first thermistor, D1-first diode;

[0036] 13-first control module, U1-first chip, U2-second chip;

[0037] 20-second battery pack module, R2-second resistor, F2-second fuse;

[0038] 21-third switch module, Q5-fifth MOS transistor, Q6-sixth MOS transistor;

[0039] 22-fourth switch module, Q4-fourth MOS tube, PTC2-second thermistor, D2-second diode;

[0040] 23-second control module, U3-third chip, U4-fourth chip;

[0041] 30-main control module;

[0042] 1-Multiple parallel battery packs, 2-Control circuit of multi-battery pack BMS system. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present application are described in detail below in conjunction with the accompanying drawings to make the advantages and features of the present application easier to understand for those skilled in the art, thereby making a clearer definition of the scope of protection of the present application.

[0044] Please refer to the drawings, in which the same component symbols represent the same components. The principles of this application are illustrated by implementing them in an appropriate computing environment. The following description is based on the illustrated specific embodiments of this application and should not be considered as limiting other specific embodiments of this application that are not described in detail herein.

[0045] As used herein, the term "module" may refer to a software or hardware object executed on the computing system. The various components, modules, engines, and services described herein may be implemented on the computing system. The devices and methods described herein may be implemented in software or hardware, and are all within the scope of this application.

[0046] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0047] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0048] Example 1

[0049] See also Figure 1 , Figure 1The following figure shows a schematic diagram of the control circuit of a multi-battery pack BMS system provided in an embodiment of the present application. The system includes a main control module 30, a first battery pack module 10, and a second battery pack module 20. The first and second battery pack modules 10, 20 are primarily used for charging and discharging connections with the main control module 30. It is worth noting that the structures of the battery pack modules are identical. While this embodiment illustrates two battery pack modules connected in parallel, the number of battery pack modules can be adjusted as needed.

[0050] For details, please refer to Figure 2 , Figure 2 A circuit module diagram of a control circuit of a multi-battery pack BMS system provided in an embodiment of the present application is shown.

[0051] The first battery pack module 10 is provided with a plurality of battery cells, a first switch module 11 , a second switch module 12 and a first control module 13 .

[0052] In this embodiment, the positive electrode of the battery cell is connected to the first port of the first switch module 11, and the negative electrode is connected to the negative port 30P- / C- of the main control module 30. The second port of the first switch module 11 is connected to the positive port 30_P+ / C+ of the main control module 30. The first switch module 11 is mainly used to conduct the charge and discharge circuit.

[0053] In this embodiment, the second switch module 12 is primarily used to limit the charging current between the first battery pack module 10 and the second battery pack module 20 and to protect the external output. The second switch module 12 includes at least a first MOS transistor Q1, a first thermistor PTC1, and a first diode D1. The source of the first MOS transistor Q1 is connected to the third port of the first switch module 11, and the drain is connected to the anode of the first diode D1 via the first thermistor PTC1. The cathode of the first diode D1 is connected to the second port of the first switch module 11. The first MOS transistor Q1 is primarily used to protect the external output of the battery pack module. The first diode D1 is primarily used to block the charging current between the first battery pack module 10 and the second battery pack module 20. The first thermistor PTC1 is primarily used to limit the external output current, which not only reduces the instantaneous inrush current to the battery pack modules in other parallel circuits when the battery pack modules are connected in parallel to the network, but also effectively protects the second switch module 12 circuit from external short circuits.

[0054] In this embodiment, the first control module 13 is communicatively connected to the main control module 30. Its first control terminal is connected to the control terminal of the first switch module 11, and its second control terminal is connected to the gate of the first MOS transistor Q1. The first control module 13 is primarily configured to communicate with the main control module 30 and control the conduction of the first switch module 11 and the second switch module 12, respectively. The first control module 13 can communicate with the main control module 30 to obtain the operating status of each battery pack module in the circuit. It can also exchange information between battery pack modules via a communication line network.

[0055] The second battery pack module 20 is provided with a plurality of battery cells, a third switch module 21, a fourth switch module 22, and a second control module 23. The structure of the second battery pack module 20 is the same as that of the first battery pack module 10, that is, the third switch module 21 corresponds to the first switch module 11, the fourth switch module 22 corresponds to the second switch module 12, and the second control module 23 corresponds to the first control module 13.

[0056] Through the above structural connection, the working principle of this embodiment can be:

[0057] If the second battery pack module 20 is already charging in the entire network or powering the main control module 30, the third switch module 21 of the main circuit is turned on and the fourth switch module 22 is turned off. Before the first battery pack module 10 is connected to the parallel power supply network, the first switch module 11 must be turned off and the second switch module 12 must be turned on to power the main control module 30. After the first and second battery pack modules 10, 20, are connected in parallel with the main control module 30, the first control module 13 of the first battery pack module 10 will establish a communication connection with the main control module 30.

[0058] When the communication connection is completed, the switches of the first switch module 11, the second switch module 12, the third switch module 21 and the fourth switch module 22 can be controlled by obtaining the working status of each battery pack module in the loop, so that the first battery pack module 10 and the second battery pack module 20 can independently judge and control the charging and discharging through the information obtained through communication, so as to achieve the effect that the first battery pack module 10 and the second battery pack module 20 do not need to distinguish between the main and secondary battery packs for charging and discharging.

[0059] When the communication connection is unsuccessful, this situation is regarded as prohibiting the first battery pack module 10 from charging and discharging. The present application also supports the first battery pack module 10 and the second battery pack module 20 being connected to the main control module 30 at the same time, and the working principle is the same.

[0060] Example 2

[0061] Based on the previous embodiment, the difference of this embodiment is:

[0062] Combine Figure 3 and Figure 4 , Figure 3 A circuit diagram of a control circuit of a multi-battery pack BMS system provided in an embodiment of the present application is shown.

[0063] Figure 4 A circuit diagram of the first switch module 11 provided in an embodiment of the present application is shown.

[0064] For the first battery pack module 10:

[0065] The circuit further includes a first resistor R1 , which is connected between the negative electrode of the battery cell and the negative port 30_P− / C− of the main control module 30 .

[0066] The first control module 13 includes a first chip U1 and a second chip U2. The first signal terminal U1_CHARGER_IN of the first chip U1 is connected to the second port 112 of the first switch module 11. The second signal terminal U1_ISP and the third signal terminal U1_ISN of the first chip U1 are connected in parallel across a first resistor R1. The first resistor R1 is primarily used to enable the first chip U1 to obtain a current signal from the loop. The data terminal U1_COM of the first chip U1 is connected to the first communication terminal U2_COM of the second chip U2, and the output terminal group is connected to the control terminal of the first switch module 11. The second communication terminal U2_EX_COM1 of the second chip U2 is connected to the communication port 30_EX_COM1 of the main control module 30, the identification terminal U2_ID1 is connected to the identification port 30_ID1 of the main control module 30, and the output terminal U2_I / O is connected to the gate of the first MOS transistor Q1. The first chip U1 is primarily used to obtain information such as voltage, current, and temperature within the battery pack and to control the first switch module 11. The second chip U2 is respectively connected to the first chip U1 and the main control module 30 for communication, and is mainly used to collect information through the first chip U1 and transmit the information to the main control module 30 and other battery pack modules through the communication port 30_EX_COM1, and control the second switch module 12.

[0067] In this embodiment, the first chip U1 is a chip with a high-end driver function, and its model may be BQ76952 or BQ76942. The second chip U2 is a chip with a communication function, and its model may be ES8P5066.

[0068] In this embodiment, the identification terminal U2_ID1 of the second chip U2 determines the level of the resistance of the identification port 30_ID1 on the main control module 30. When the first battery pack module 10 and the main control module 30 are connected, if the identification level is incorrect, the first battery pack module 10 will shut down the first switch module 11 and the second switch module 12 to prevent the high-capacity battery pack from charging the low-capacity battery pack. At the same time, after the first battery pack module 10 enters a dormant state, if the first battery pack module 10 is detected by the ID port as being removed from the motherboard, the first battery pack module 10 can quickly wake up the second chip U2 by using the level of the identification terminal U2_ID1, shutting down the first switch module 11 and the second switch module 12 to prevent the low-capacity battery pack from being charged when the first battery pack module 10 is inserted into the main control module 30 again.

[0069] In this embodiment, the first switch module 11 includes a second MOS transistor Q2 and a third MOS transistor Q3. The gate of the second MOS transistor Q2 is connected to the first output terminal U1_CHG of the first chip U1, the source is connected to the positive electrode of the battery cell, and the drain is connected to the drain of the third MOS transistor Q3. The gate of the third MOS transistor Q3 is connected to the second output terminal U1_DSG of the first chip U1, and the source is connected to the positive port 30_P+ / C+ of the main control module 30. The source of the first MOS transistor Q1 is connected to the drain of the second MOS transistor Q2. The second MOS transistor Q2 functions as a charging switch in the circuit, and the third MOS transistor Q3 functions as a discharging switch in the circuit.

[0070] In this embodiment, the first switch module 11 may also be provided with multiple second MOS transistors Q2 and multiple third MOS transistors Q3. The sources, gates, and drains of each second MOS transistor Q2 are connected in parallel. The sources, gates, and drains of each third MOS transistor Q3 are connected in parallel. The parallel connection of multiple second MOS transistors Q2 and multiple third MOS transistors Q3 is primarily used to drive high-power loads.

[0071] In this embodiment, the first MOS transistor Q1 is a P-channel MOS transistor, and the second MOS transistor Q2 and the third MOS transistor Q3 are both N-channel MOS transistors.

[0072] The circuit further includes a first fuse F1, which is connected between the positive electrode of the battery cell and the first port 111 of the first switch module 11. The first fuse F1 is mainly used for overload protection.

[0073] The second battery pack module 20 has the same structure as the first battery pack module 10. The fourth switch module 22 includes a fourth MOS transistor Q4, a second thermistor PTC2, and a second diode D2. The fourth MOS transistor Q4 corresponds to the first MOS transistor Q1, the second thermistor PTC2 corresponds to the first thermistor PTC1, and the second diode D2 corresponds to the first diode D1. The third switch module 21 includes a fifth MOS transistor Q5 and a sixth MOS transistor Q6. The fifth MOS transistor Q5 corresponds to the second MOS transistor Q2, and the sixth MOS transistor Q6 corresponds to the third MOS transistor Q3. The second control module 23 includes a third chip U3 and a fourth chip U4. The third chip U3 corresponds to the first chip U1, and the fourth chip U4 corresponds to the second chip U2. The circuit also includes a second resistor R2 and a second fuse F2. The second resistor R2 corresponds to the first resistor R1, and the second fuse F2 corresponds to the first fuse F1.

[0074] Through the above structural connection, the working principle of this embodiment can be:

[0075] If the second battery pack module 20 is already charging in the entire network or powering the main control module 30, the third switch module 21 of the main circuit is turned on and the fourth switch module 22 is turned off. Before the first battery pack module 10 is connected to the parallel power supply network, the first switch module 11 must be turned off and the second switch module 12 must be turned on to power the main control module 30. After the first and second battery pack modules 10 and 20 are connected in parallel with the main control module 30, the identification terminal U2_ID1 of the second chip U2 determines the level of the resistance of the identification port 30_ID1 on the main control module 30, and the first control module 13 of the first battery pack module 10 attempts to establish a communication connection with the main control module 30.

[0076] When the communication connection is completed and the ID level is correctly identified, its working logic can be divided into charging operation logic and discharging operation logic, as follows.

[0077] Charging operation logic: When the power level of the first battery pack module 10 is higher than that of the second battery pack module 20, the first control module 13 turns off the first MOS tube Q1 and the first switch module 11, and the second control module 23 controls the third switch module 21 to be in the open state, that is, to achieve the effect of charging the second battery pack module 20 first.

[0078] When the power level of the first battery pack module 10 is lower than that of the second battery pack module 20, the first control module 13 turns on the first switch module 11 and turns off the first MOS tube Q1, and the second control module 23 turns off the third switch module 21, thereby giving priority to charging the first battery pack module 10.

[0079] When the power level of the first battery pack module 10 is the same as that of the second battery pack module 20, the first control module 13 turns on the first switch module 11 and turns off the first MOS tube Q1, and the second control module 23 keeps the third switch module 21 open, thereby achieving the effect of charging the first battery pack module 10 and the second battery pack module 20 at the same time.

[0080] Discharge Operation Logic: When the charge level of the first battery pack module 10 is higher than that of the second battery pack module 20, the second control module 23 turns on the sixth MOS transistor Q6, turning off the fifth MOS transistor Q5 first. The diode inside the fifth MOS transistor Q5 then discharges the current through the entire device. The first control module 13 turns on the second and third MOS transistors Q2 and Q3, then turns off the first MOS transistor Q1. The second control module 23 then controls the sixth MOS transistor Q6 to turn off. During the switching process, the first battery pack module 10 discharges, while the second battery pack module 20 assists in the discharge. After the switching is complete, the first battery pack module 10 is fully powered.

[0081] When the voltage of the first battery pack module 10 is lower than that of the second battery pack module 20 , the first control module 13 turns off the first MOS transistor Q1 , the second MOS transistor Q2 , and the third MOS transistor Q3 to achieve the discharge effect of the second battery pack module 20 .

[0082] When the voltage of the first battery pack module 10 is the same as that of the second battery pack module 20, the first control module 13 turns on the first switch module 11 and turns off the first MOS tube Q1, and the second control module 23 keeps the third switch module 21 open, so that the first battery pack module 10 and the second battery pack module 20 are discharged at the same time.

[0083] In the above discharge logic, the biggest advantage is that the discharge current is briefly passed through the body diode of the main charging MOS tube, that is, the second MOS tube Q2 and the fifth MOS tube Q5, which can realize seamless output power supply switching between battery pack modules during the discharge process of the whole machine.

[0084] If the communication connection is unsuccessful or the ID level recognition is incorrect, the first battery pack module 10 is prohibited from charging or discharging. Only when the battery pack recognizes a pre-set level, which is different from the ID level when connected to the motherboard, is the first battery pack module 10 allowed to charge and discharge independently offline.

[0085] Example 3

[0086] This embodiment provides a control method for a multi-battery pack BMS system, which is applied to the control circuit of the multi-battery pack BMS system as described in the first or second embodiment.

[0087] like Figure 5 As shown, Figure 5The following is a flowchart illustrating a control method for a multi-battery pack BMS system according to an embodiment of the present application. The method includes:

[0088] S101, forming a power supply circuit between the battery cell and the main control module 30;

[0089] S102, the first switch module 11 controls the conduction between the battery cell and the main control module 30;

[0090] S103, the second switch module 12 is connected in parallel between the second port 112 and the third port 113 of the first switch module 11, and limits the charging current between the battery pack modules and protects the external output;

[0091] S104 , the first control module 13 is in communication with the main control module 30 , and controls the conduction of the first switch module 11 and the second switch module 12 respectively according to the working status of each battery pack module in the loop.

[0092] In step S101 , the positive electrode of the battery cell is connected to the positive port 30_P+ / C+ of the main control module 30 , and the negative electrode is connected to the negative port 30_P− / C− of the main control module 30 , thereby forming a loop.

[0093] In step S102, the first port 111 of the first switch module 11 is connected to the positive pole of the battery cell, and the second port 112 of the first switch module 11 is connected to the positive port 30_P+ / C+ of the main control module 30. The conduction between the battery cell and the main control module 30 is controlled by the conduction of the first switch module 11, so as to perform charging and discharging.

[0094] In step S103 , the second switch module 12 is connected in parallel between the second port 112 and the third port 113 of the first switch module 11 , mainly for limiting the charging current between the battery pack modules and protecting the external output.

[0095] In step S104, the first control module 13 is communicatively connected to the main control module 30, and the conduction of the first switch module 11 and the second switch module 12 is controlled based on the operating status of each battery pack module in the circuit. The status of all battery packs in the circuit can be obtained through the main control module 30, or it can be obtained independently of the main control module 30, directly using communication lines to achieve information exchange between the battery pack modules, which is relatively flexible. This allows control of the first switch module 11 and the second switch module 12.

[0096] In this embodiment, the second switch module 12 includes at least a first MOS transistor Q1, a first thermistor PTC1, and a first diode D1. The source of the first MOS transistor Q1 is connected to the third port 113 of the first switch module 11, and the drain is connected to the anode of the first diode D1 through the first thermistor PTC1. The cathode of the first diode D1 is connected to the second port 112 of the first switch module 11. The first MOS transistor Q1 is mainly used for external output protection of the battery pack module. The first diode D1 is mainly used to block the charging current between the first battery pack module 10 and the second battery pack module 20. The first thermistor PTC1 is mainly used to limit the external output current, which can not only reduce the instantaneous impact current on the battery pack modules in other parallel circuits when the battery pack modules are connected in parallel to the network, but also effectively protect the second switch module 12 circuit from external short circuit.

[0097] It is worth noting that the structures of the battery pack modules are the same, and the number of battery pack modules can be set according to needs. For specific description, please refer to the control circuit of a multi-battery pack BMS system provided in Example 1 or Example 2.

[0098] Example 4

[0099] like Figure 6 As shown, this embodiment provides a multi-parallel battery pack 1, including the control circuit 2 of the multi-battery pack BMS system as described in the first or second embodiment.

[0100] The above describes the implementation methods of the present application in detail in conjunction with the accompanying drawings, but the present application is not limited to the above implementation methods. Various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present application.

Claims

1. A control circuit for a multi-battery pack BMS system, characterized in that: include: A main control module (30), used to control the usage status of the battery pack; A plurality of battery pack modules, each of which is provided with a plurality of battery cells, a first switch module (11), a second switch module (12), and a first control module (13), and is used for charging and discharging connection with the main control module (30); The battery cell is connected to the main control module (30) to form a loop; the first port (111) of the first switch module (11) is connected to the positive electrode of the battery cell, and the second port (112) is connected to the positive port 30_P+ / C+ of the main control module (30); the second switch module (12) includes a first MOS tube Q1 for external output protection of the battery pack module, a first diode D1 for blocking the charging current between the battery pack modules, and a first thermistor PTC1 for limiting the external output current. The source of Q1 is connected to the third port (113) of the first switch module (11), and the drain is connected to the anode of the first diode D1 through the first thermistor PTC1; the cathode of the first diode D1 is connected to the second port (112) of the first switch module (11); the first control module (13) is communicatively connected to the main control module (30), the first control end is connected to the control end of the first switch module (11), and the second control end is connected to the gate of the first MOS tube Q1; the first MOS tube Q1 is a P-channel MOS tube; The first control module (13) comprises a first chip U1 for controlling the first switch module (11) and a second chip U2 for controlling the second switch module (12); the first chip U1 is a chip with a driving function, and the second chip U2 is a chip with a communication function.

2. The control circuit of the multi-battery pack BMS system according to claim 1, characterized in that: The circuit further comprises a first resistor R1, wherein the first resistor R1 is connected between the negative electrode of the battery cell and the negative port 30_P- / C- of the main control module (30).

3. The control circuit of the multi-battery pack BMS system according to claim 2, characterized in that: The first signal terminal U1_CHARGER_IN of the first chip U1 is connected to the second port (112) of the first switch module (11), the second signal terminal U1_ISP and the third signal terminal U1_ISN are connected in parallel to the two ends of the first resistor R1, the data terminal U1_COM is connected to the first communication terminal U2_COM of the second chip U2, and the output terminal group is connected to the control terminal of the first switch module (11); the second communication terminal U2_EX_COM1 of the second chip U2 is connected to the communication port 30_EX_COM1 of the main control module (30), the identification terminal U2_ID1 is connected to the identification port 30_ID1 of the main control module (30), and the output terminal U2_I / O is connected to the gate of the first MOS tube Q1.

4. The control circuit of the multi-battery pack BMS system according to claim 3, characterized in that: The first switch module (11) comprises a second MOS transistor Q2 and a third MOS transistor Q3; the gate of the second MOS transistor Q2 is connected to the first output terminal U1_CHG of the first chip U1, the source is connected to the positive electrode of the battery cell, and the drain is connected to the drain of the third MOS transistor Q3; the gate of the third MOS transistor Q3 is connected to the second output terminal U1_DSG of the first chip U1, and the source is connected to the positive port 30_P+ / C+ of the main control module (30); the source of the first MOS transistor Q1 is connected to the drain of the second MOS transistor Q2.

5. The control circuit of the multi-battery pack BMS system according to claim 4, characterized in that: The first switch module (11) is provided with a plurality of second MOS tubes Q2 and a plurality of third MOS tubes Q3, wherein the sources of the second MOS tubes Q2 are connected in parallel, the gates are connected in parallel, and the drains are connected in parallel; and the sources of the third MOS tubes Q3 are connected in parallel, the gates are connected in parallel, and the drains are connected in parallel.

6. The control circuit of the multi-battery pack BMS system according to claim 4, characterized in that: The second MOS transistor Q2 and the third MOS transistor Q3 are both N-channel MOS transistors.

7. The control circuit of the multi-battery pack BMS system according to claim 4, characterized in that: The circuit further includes a first fuse F1 connected between the positive electrode of the battery cell and the source electrode of the second MOS transistor Q2.

8. A control method for a multi-battery pack BMS system, characterized in that: The method is applied to the control circuit of the multi-battery pack BMS system according to any one of claims 1 to 7, and the method includes: A power supply circuit is formed between the battery cell and the main control module (30); A first switch module (11) controls conduction between the battery cell and the main control module (30); The second switch module (12) is connected in parallel between the second port (112) and the third port (113) of the first switch module (11), and limits the charging current between the battery pack modules and protects the external output; The first control module (13) is in communication connection with the main control module (30) and controls the conduction of the first switch module (11) and the second switch module (12) respectively according to the working status of each battery pack module in the loop.

9. The control method of a multi-battery pack BMS system according to claim 8, characterized in that: The second switch module (12) comprises a first MOS tube Q1 for external output protection of the battery pack module, a first diode D1 for blocking the charging current between the battery pack modules, and a first thermistor PTC1 for limiting the external output current; The source of the first MOS tube Q1 is connected to the third port (113) of the first switch module (11), and the drain is connected to the anode of the first diode D1 via the first thermistor PTC1; the cathode of the first diode D1 is connected to the second port (112) of the first switch module (11).

10. A multi-parallel battery pack, characterized in that: The control circuit comprises the multi-battery pack BMS system according to any one of claims 1 to 7.

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