Multi-battery pack dynamic hot plug cooperative control method and device

Abstract

The invention discloses a multi-battery pack dynamic hot plug cooperative control method and device. Relates to the battery pack field. When an external charging request signal is detected, other battery packs except the battery pack with the lowest voltage are controlled to enter a pre-charging state or a discharging disconnection state according to the voltage difference between the battery packs and the common bus, so that the pre-charging state or the discharging disconnection state of the battery packs is controlled; then, the battery pack with the lowest voltage is preferentially controlled to be connected to the common bus for charging when the first voltage matching condition is met; then, when the remaining unconnected battery packs meet a first voltage matching condition, the remaining unconnected battery packs are controlled to be connected to the common bus through the charging and discharging control circuit to participate in charging, and step-by-step parallel connection is achieved; when a discharging request signal is detected, the battery pack with the highest voltage is controlled to be preferentially connected to the common bus to participate in discharging, and then the remaining battery packs are sequentially connected step by step when a second voltage matching condition is met. Through the cooperative control, ordered and impact-free parallel connection of the hot plug process of the multiple battery packs is realized.

Description

Technical Field

[0001] This invention relates to the field of battery packs, and more particularly to a method and apparatus for dynamic hot-swappable collaborative control of multiple battery packs. Background Technology

[0002] With the increasing prevalence of parallel multi-battery pack applications, achieving safe, reliable, and shock-free hot-swapping of battery packs has become a key technological challenge for new energy systems. Traditional solutions typically rely on fuses for electrical isolation, which suffers from high cost, short lifespan, and susceptibility to arcing, and lacks dynamic judgment and intelligent control mechanisms for voltage differences between battery packs. When multiple battery packs are directly connected in parallel due to voltage inconsistencies, significant circulating currents can easily occur, leading to increased temperature rise, capacity mismatch, and even malfunctions in BMS protection, affecting system stability and lifespan. Existing technologies for battery pack connection control often employ fixed timing or simple on / off logic, which is difficult to adapt to dynamic voltage changes under complex operating conditions, especially when charging requests are triggered, lacking a collaborative management mechanism for the voltage status of each battery pack. Summary of the Invention

[0003] To address the issues of circulating current surges, arcing risks, and connection timing disruptions caused by voltage differences during hot-swapping of multiple battery packs, this invention proposes a dynamic hot-swapping collaborative control method for multiple battery packs. This method is applied to a multi-battery pack coordinated control system, which includes a common bus for connecting to an external power source or load; each battery pack is equipped with a charge / discharge control circuit; and each battery pack is connected to the common bus through its corresponding charge / discharge control circuit. The method includes:

[0004] When the battery pack is in a charging or discharging state, the BMS system detects a charging wake-up request signal or a discharging request signal, and then detects the number of all battery packs waiting in place in the multi-battery pack coordination control system. If there are multiple battery packs waiting in place, the system obtains the real-time voltage of each battery pack waiting in place and sorts them by voltage value. The battery packs waiting in place are those that have been physically inserted but have not been connected to the common bus.

[0005] When the BMS system detects a charging wake-up request signal, for the battery packs waiting in place, excluding the battery pack with the lowest voltage, the corresponding operation is performed based on their voltage relationship with the common bus:

[0006] If its voltage is higher than the common bus voltage and the voltage difference is greater than the first preset threshold, its charging and discharging control circuit is controlled to enter the pre-charge state and locked. If its voltage is higher than the common bus voltage and the voltage difference is less than or equal to the first preset threshold, or its voltage is lower than or equal to the common bus voltage, its charging and discharging control circuit is controlled to be in the discharge disconnect state and locked. Subsequently, when the battery pack with the lowest control voltage meets the first voltage matching condition, it is connected to the common bus through its charging and discharging control circuit to participate in charging. Then, the battery packs that are not connected to the common bus are connected to the common bus through their charging and discharging control circuits to participate in charging when the first voltage matching condition is met, so as to achieve parallel connection in stages until all battery packs are connected in parallel for charging.

[0007] When the BMS system detects a discharge request signal, it controls the battery pack with the highest voltage among the waiting battery packs to connect to the common bus through its charge and discharge control circuit to participate in the discharge. Then, the remaining waiting battery packs that are not connected to the common bus are connected to the common bus to participate in the discharge when the second voltage matching condition is met, so as to achieve parallel connection in stages until all battery packs have completed parallel discharge.

[0008] Furthermore, when the first voltage matching condition is met, the battery pack with the lowest control voltage is connected to the common bus for charging via its charge / discharge control circuit, specifically:

[0009] If the voltage of the battery pack with the lowest voltage is higher than the voltage of the common bus and the voltage difference between the two is greater than the first preset threshold, then the battery pack is controlled to enter the pre-charge state. After the voltage difference between the battery pack and the common bus meets the first voltage matching condition, the battery pack is controlled to connect to the common bus through the charge and discharge control circuit to participate in charging. (The battery pack with the lowest voltage refers to the battery pack with the lowest voltage that is waiting in place.)

[0010] If the voltage difference between the two meets the first voltage matching condition, the battery pack is directly controlled to connect to the common bus for charging through the charge and discharge control circuit.

[0011] If the voltage of the common bus is higher than the voltage of the battery pack with the lowest voltage, then the battery pack is subjected to voltage synchronization operation until the difference between the voltage of the battery pack with the lowest voltage and the voltage of the common bus meets the first voltage matching condition. Then, the battery pack is controlled to connect to the common bus through the charge and discharge control circuit to participate in charging.

[0012] Furthermore, the step of sequentially connecting battery packs not connected to the common bus to participate in charging via the charge / discharge control circuit when the first voltage matching condition is met, thereby achieving parallel connection at each stage, until all battery packs have completed parallel charging; specifically:

[0013] The system continuously monitors the parallel voltage of currently connected battery packs (i.e., the common bus voltage) and compares it with the lowest voltage among the remaining battery packs not connected to the common bus. Based on the comparison result and the current state of the battery pack with the lowest voltage, the system performs the corresponding operation:

[0014] For a battery pack in the pre-charge state, if the voltage difference between it and the common bus voltage meets the first voltage matching condition, it is controlled to exit the pre-charge state and connected to the common bus to participate in charging through the charge and discharge control circuit; if it does not meet the condition and its voltage is higher than the common bus voltage, the pre-charge state is maintained until the condition is met.

[0015] For a battery pack in the discharge disconnected state, if the voltage difference between it and the common bus voltage meets the first voltage matching condition, it is directly controlled to connect to the common bus through the charge and discharge control circuit to participate in charging.

[0016] If the voltage of the battery pack with the lowest voltage is lower than the voltage of the common bus, and the difference is greater than the first preset threshold, then the battery pack will be subjected to voltage synchronization operation until the difference between the voltage of the lowest voltage pack and the voltage of the common bus meets the first voltage matching condition, and then it will be controlled to connect to the common bus through the charge and discharge control circuit to participate in charging.

[0017] Repeat the above process until all battery packs have completed parallel charging.

[0018] Furthermore, the step of sequentially connecting the remaining battery packs that are not yet connected to the common bus to participate in discharge when the second voltage matching condition is met, thereby achieving parallel connection at each stage, until all battery packs have completed parallel discharge, specifically involves:

[0019] The voltage difference between the voltage of the connected battery pack or the parallel voltage of multiple connected battery packs and the highest voltage among the remaining battery packs not connected to the common bus is monitored in real time. When the voltage difference is less than a second preset threshold, the highest voltage is controlled to connect to the common bus to participate in the discharge, realizing the step-by-step parallel connection until all battery packs have completed parallel discharge.

[0020] Furthermore, the number of all in-situ waiting battery packs in the multi-battery pack coordination control system is detected. If only one exists, then:

[0021] When the BMS system detects a charging wake-up request signal, perform the following operations:

[0022] If the voltage of the battery pack waiting in place is higher than the voltage of the common bus and the voltage difference between the two is greater than the first preset threshold, the battery pack is controlled to enter the pre-charge state. After the voltage difference between the battery pack and the common bus meets the first voltage matching condition, the battery pack is controlled to connect to the common bus for charging through the charge and discharge control circuit.

[0023] If the voltage difference between the two meets the first voltage matching condition, the battery pack is directly controlled to be connected to the common bus for charging through the charge and discharge control circuit.

[0024] If the voltage of the battery pack waiting in place is lower than the voltage of the common bus and the difference is greater than the first preset threshold, then the battery pack is subjected to voltage synchronization operation until the difference between the voltage of the battery pack and the voltage of the common bus meets the first voltage matching condition, and then it is controlled to connect to the common bus through the charge and discharge control circuit to participate in charging.

[0025] When the BMS system detects a discharge request signal, perform the following operations:

[0026] The battery pack in place is connected to the common bus to participate in the discharge through its charge and discharge control circuit.

[0027] Furthermore, the charge / discharge control circuit is used, under the control of the BMS system, to turn on or off the charging connection, discharging connection, and pre-charging connection between the corresponding battery pack and the common bus.

[0028] Furthermore, the charge / discharge control circuit includes a MOS switch or relay for turning on or off the charging connection, the discharging connection, and the pre-charge connection.

[0029] Furthermore, the charge / discharge control circuit specifically includes:

[0030] The system comprises a first MOS switch, a second MOS switch, a third MOS switch, and a first resistor; wherein:

[0031] After the source of the first MOS switch is connected to the source of the third MOS switch, it is connected to the negative terminal of the corresponding battery pack. The gate of the first MOS switch is connected to the discharge control signal or the turn-off control signal issued by the BMS system, and the drain is connected to one end of the first resistor and then connected to the drain of the second MOS switch. The drain of the third MOS switch is connected to the other end of the first resistor, and the gate is connected to the pre-charge control signal or the turn-off control signal issued by the BMS system. The gate of the second MOS switch is connected to the charging control signal or the turn-off control signal, and the source is connected to the negative terminal of the common bus. The positive terminal of the battery pack is connected to the positive terminal of the common bus.

[0032] Furthermore, in the pre-charge state: the third MOS switch is turned on based on the pre-charge control signal issued by the BMS system, and the first MOS switch and the second MOS switch are turned off; the current is current-limited to charge the common bus side capacitor through the third MOS switch and the first resistor, so that the common bus voltage gradually rises to be close to the corresponding battery pack voltage.

[0033] The control of exiting the pre-charge state and connecting to the common bus for charging via the charge and discharge control circuit is as follows: after the first voltage matching condition is met, the BMS system outputs a corresponding shutdown control signal to disconnect the third MOS switch and cut off the pre-charge connection; then, it outputs a charging control signal to turn on the second MOS switch, establishes a charging connection, and realizes stable connection of the battery pack to the common bus for charging.

[0034] In the discharged disconnected state: the first MOS switch, the second MOS switch and the third MOS switch are all in the disconnected state, and the charging and discharging path between the battery pack and the common bus is completely cut off, achieving electrical isolation.

[0035] Furthermore, the connection to the common bus for discharge specifically refers to:

[0036] The discharge control signal output by the BMS system turns on the first MOS switch to establish a discharge connection; if the third MOS switch is in the on state, it is simultaneously turned off to complete the stable connection of the battery pack to the common bus for discharge.

[0037] Furthermore, the first voltage matching condition is that the voltage difference is less than or equal to a first preset threshold.

[0038] The voltage synchronization operation for the battery pack specifically involves:

[0039] Disconnect the second MOS switch corresponding to each battery pack that is charging, and turn on its third MOS switch;

[0040] Then the second MOS switch controlling the lower voltage battery pack is turned on to start charging;

[0041] When the voltage difference between the battery pack and the common bus voltage is less than or equal to the first preset threshold, the third MOS switch of each battery pack that is currently being charged is disconnected, and its second MOS switch is turned on to restore the charging connection and realize parallel charging of multiple battery packs.

[0042] This invention also proposes a multi-battery pack dynamic hot-swap cooperative control device, applied to a multi-battery pack coordinated control system. The system includes a common bus for connecting an external power source or load; each battery pack is equipped with a charge / discharge control circuit; each battery pack is connected to the common bus through its corresponding charge / discharge control circuit; the device includes:

[0043] The in-situ detection module is used to detect the number of all battery packs waiting in the multi-battery pack coordination control system when the BMS system detects a charging wake-up request signal or a discharging request signal while the battery pack is in a charging or discharging state. If there are multiple in-situ waiting battery packs, the module obtains the real-time voltage of each in-situ waiting battery pack and sorts them by voltage value. The in-situ waiting battery packs are those that have completed physical insertion but have not been connected to the common bus.

[0044] The charging control module, when the BMS system detects a charging wake-up request signal, performs corresponding operations based on the voltage relationship between the battery packs (excluding the one with the lowest voltage) and the common bus for the other battery packs waiting in place.

[0045] If its voltage is higher than the common bus voltage and the voltage difference is greater than the first preset threshold, its charging and discharging control circuit is controlled to enter the pre-charging state and locked in this state; if its voltage is higher than the common bus voltage and the voltage difference is less than or equal to the first preset threshold, or its voltage is lower than or equal to the common bus voltage, its charging and discharging control circuit is controlled to be in the discharging disconnect state and locked in this state; the battery pack with the lowest control voltage is connected to the common bus to participate in charging through its charging and discharging control circuit when the first voltage matching condition is met; the battery packs not connected to the common bus are connected to the common bus to participate in charging through their charging and discharging control circuits when the first voltage matching condition is met, so as to achieve parallel connection in stages until all battery packs are connected in parallel for charging.

[0046] The discharge control module is used to control the battery pack with the highest voltage among the waiting battery packs to connect to the common bus through its charge and discharge control circuit when the BMS system detects a discharge request signal. Then, the remaining waiting battery packs that are not connected to the common bus are connected to the common bus to participate in the discharge when the second voltage matching condition is met, so as to realize the parallel connection in stages until all battery packs have completed the parallel discharge.

[0047] Compared with the prior art, the present invention has at least the following beneficial effects:

[0048] (1) When the present invention detects that there are multiple battery packs waiting in the system, it acquires the real-time voltage of each battery pack and sorts them according to the voltage value; when the BMS system detects an external charging request signal, it controls the other battery packs waiting in the system, except for the battery pack with the lowest voltage, to enter the pre-charge state or the discharge disconnect state according to the voltage difference between them and the common bus, and locks the state; then, it prioritizes controlling the battery pack with the lowest voltage to connect to the common bus to participate in charging when the first voltage matching condition is met; then, it sequentially connects the remaining battery packs waiting in the system that are not connected to the common bus to participate in charging through their charging and discharging control circuits when the first voltage matching condition is met, so as to realize the parallel connection in stages until all battery packs are charged in parallel; when the BMS system detects a discharge request signal, it prioritizes controlling the battery pack waiting in the system with the highest voltage to connect to the common bus to participate in discharging, and then sequentially connects the remaining battery packs waiting in the system when the second voltage matching condition is met, so as to realize the parallel discharge in stages. Through the above-mentioned coordinated control, the orderly and shock-free parallel connection of multiple battery pack hot-swapping processes is realized, effectively avoiding problems such as circulating current, arcing and BMS false protection caused by voltage dispersion, and significantly improving the safety and operational stability of the system.

[0049] (2) By establishing an active locking mechanism of "pre-charge state" and "discharge disconnect state", the present invention pre-sets the state of the remaining battery packs waiting in place except the battery pack with the lowest voltage at the beginning of charging, preventing them from being accidentally turned on when the bus voltage is not matched. This avoids voltage conflicts and instantaneous large current impacts caused by multiple packs being connected at the same time, significantly reduces the electrical stress on the MOSFET and BMS system, and improves the reliability and lifespan of the system.

[0050] (3) The present invention uses parallel voltage as the matching benchmark for subsequent battery pack access. Combined with real-time voltage difference judgment and pre-charge control strategy, it realizes the step-by-step and optimal parallel connection of the remaining battery packs not connected to the common bus. For battery packs with low voltage, the voltage difference is reduced through voltage synchronization operation to ensure that the access process is smooth and controllable, effectively improving the energy coordination efficiency and thermal management performance of the multi-battery pack system.

[0051] (4) Based on the hardware architecture of three MOS switches (discharge MOS, charge MOS, precharge MOS), the present invention precisely controls the on / off timing of each MOS through the BMS system, realizing physical isolation and safe switching of the charging / discharging and precharge circuits, replacing the traditional relay + fuse solution, which not only reduces system cost and size, but also avoids problems such as oxidation and adhesion of mechanical contacts, significantly improving the response speed, repeatability and long-term reliability of hot-swap operation. Attached Figure Description

[0052] Figure 1 This is a circuit diagram of the charge and discharge control system according to an embodiment of the present invention;

[0053] Figure 2 This is a circuit diagram of a parallel voltage detection circuit for a battery pack connected in parallel according to an embodiment of the present invention. Detailed Implementation

[0054] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0055] This embodiment proposes a multi-battery pack dynamic hot-swap collaborative control method, which is applicable to application scenarios where battery packs are plugged in and out when the user is parked in an electric vehicle or energy storage system.

[0056] During the operation of a multi-battery pack system, when a new battery pack needs to be connected to the common bus for charging while other battery packs are charging, traditional control strategies are prone to triggering differential voltage protection mechanisms due to the large voltage difference between the newly connected battery pack and the bus, leading to system power outages. Alternatively, they may incorrectly maintain the high-voltage battery pack to continue charging while failing to activate the low-voltage battery pack in time, resulting in a continuous widening of the SOC difference among the battery packs, energy distribution imbalance, and decreased capacity utilization. When the low-voltage battery pack finishes charging and needs to switch to the high-voltage battery pack for discharging, improper control timing can easily cause a delay in the discharge circuit switching, leading to a brief load interruption, or cause the low-voltage battery pack to continue discharging, rapidly depleting its SOC, while the high-voltage battery pack fails to provide power in time, resulting in energy waste and reduced system efficiency.

[0057] Furthermore, when only one battery pack is operating, if another battery pack with a large voltage deviation is hot-plugged in, traditional systems, lacking dynamic voltage matching and priority management mechanisms, often fail to actively identify and balance the charging and discharging tasks. This results in the original operating battery pack continuously discharging or even over-discharging to a depleted state, while the newly inserted battery pack remains idle or unconnected for an extended period, failing to utilize its energy storage capacity. This embodiment, by introducing a strategy combining voltage sequencing, state prediction, and step-by-step collaborative control of MOS switches, achieves precise management of the timing of multiple battery pack connections, charging and discharging paths, and bus voltage. This effectively solves the problems of energy imbalance, system instability, and decreased reliability caused by voltage mismatch and control disorder during hot-plugging. Specifically:

[0058] This invention proposes a dynamic hot-swappable collaborative control method for multiple battery packs, which is applied to a multi-battery pack coordinated control system, the system including a common bus for connecting external power sources or loads;

[0059] Each battery pack is equipped with a charge / discharge control circuit; each battery pack is connected to the common bus through its corresponding charge / discharge control circuit.

[0060] The method includes:

[0061] When the battery pack is in a charging or discharging state, and the BMS system detects a charging wake-up request signal or a discharging request signal, it checks the number of all battery packs waiting in place in the multi-battery pack coordination control system:

[0062] If there is only one battery pack waiting in place, then:

[0063] When the BMS system detects a charging wake-up request signal, perform the following operations:

[0064] If the voltage of the battery pack waiting in place is higher than the voltage of the common bus and the voltage difference between the two is greater than the first preset threshold, the battery pack is controlled to enter the pre-charge state. After the voltage difference between the battery pack and the common bus meets the first voltage matching condition, the battery pack is controlled to connect to the common bus for charging through the charge and discharge control circuit.

[0065] If the voltage difference between the two meets the first voltage matching condition, the battery pack is directly controlled to be connected to the common bus for charging through the charge and discharge control circuit.

[0066] If the voltage of the battery pack waiting in place is lower than the voltage of the common bus and the difference is greater than the first preset threshold, then the battery pack is subjected to voltage synchronization operation until the difference between the voltage of the battery pack and the voltage of the common bus meets the first voltage matching condition, and then it is controlled to connect to the common bus through the charge and discharge control circuit to participate in charging.

[0067] When the BMS system detects a discharge request signal, perform the following operations:

[0068] The battery pack in place is connected to the common bus to participate in the discharge through its charge and discharge control circuit.

[0069] If there are multiple battery packs waiting in place, the real-time voltage of each battery pack waiting in place is obtained and sorted by voltage value; the battery packs waiting in place are those that have completed physical insertion but have not been connected to the common bus.

[0070] When the BMS system detects a charging wake-up request signal, for the battery packs waiting in place, excluding the battery pack with the lowest voltage, the corresponding operation is performed based on their voltage relationship with the common bus:

[0071] If its voltage is higher than the common bus voltage and the voltage difference is greater than the first preset threshold, its charging and discharging control circuit is controlled to enter the pre-charge state and locked. If its voltage is higher than the common bus voltage and the voltage difference is less than or equal to the first preset threshold, or its voltage is lower than or equal to the common bus voltage, its charging and discharging control circuit is controlled to be in the discharge disconnect state and locked. Subsequently, when the battery pack with the lowest control voltage meets the first voltage matching condition, it is connected to the common bus through its charging and discharging control circuit to participate in charging. Then, the battery packs that are not connected to the common bus are connected to the common bus through their charging and discharging control circuits to participate in charging when the first voltage matching condition is met, so as to achieve parallel connection in stages until all battery packs are connected in parallel for charging.

[0072] This invention establishes an active locking mechanism between "pre-charge state" and "discharge disconnect state". At the initial stage of charging, the states of the remaining battery packs waiting in place, except for the battery pack with the lowest voltage, are preset to prevent them from accidentally turning on when the bus voltage is not matched. This avoids voltage conflicts and instantaneous high current surges caused by multiple packs being connected at the same time, significantly reduces the electrical stress on the MOSFET and BMS system, and improves the reliability and lifespan of the system.

[0073] When the first voltage matching condition is met, the battery pack with the lowest control voltage is connected to the common bus for charging via its charge / discharge control circuit, specifically:

[0074] If the voltage of the battery pack with the lowest voltage is higher than the voltage of the common bus and the voltage difference between the two is greater than the first preset threshold, then the battery pack is controlled to enter the pre-charge state. After the voltage difference between the battery pack and the common bus meets the first voltage matching condition, the battery pack is controlled to connect to the common bus through the charge and discharge control circuit to participate in charging. The battery pack with the lowest voltage refers to the battery pack with the lowest voltage among the battery packs waiting in place.

[0075] If the voltage difference between the two meets the first voltage matching condition, the battery pack is directly controlled to connect to the common bus for charging through the charge and discharge control circuit.

[0076] If the voltage of the common bus is higher than the voltage of the battery pack with the lowest voltage, then the battery pack is subjected to voltage synchronization operation until the difference between the voltage of the battery pack with the lowest voltage and the voltage of the common bus meets the first voltage matching condition. Then, the battery pack is controlled to connect to the common bus through the charge and discharge control circuit to participate in charging.

[0077] The process involves sequentially connecting battery packs not currently connected to the common bus to participate in charging via a charge / discharge control circuit when the first voltage matching condition is met, achieving step-by-step parallel connection until all battery packs have completed parallel charging; specifically:

[0078] The system continuously monitors the parallel voltage of currently connected battery packs (i.e., the common bus voltage) and compares it with the lowest voltage among the remaining battery packs not connected to the common bus. Based on the comparison result and the current state of the battery pack with the lowest voltage, the system performs the corresponding operation:

[0079] For a battery pack in the pre-charge state, if the voltage difference between it and the common bus voltage meets the first voltage matching condition, it is controlled to exit the pre-charge state and connected to the common bus to participate in charging through the charge and discharge control circuit; if it does not meet the condition and its voltage is higher than the common bus voltage, the pre-charge state is maintained until the condition is met.

[0080] For a battery pack in the discharge disconnect state, if the voltage difference between it and the common bus voltage meets the first voltage matching condition, it is directly controlled to connect to the common bus through the charge and discharge control circuit to participate in charging; if it does not meet the condition and is higher than the common bus voltage, it is first controlled to enter the pre-charge state, and after the voltage difference meets the first voltage matching condition, it is then controlled to connect to the common bus to participate in charging.

[0081] If the voltage of the battery pack with the lowest voltage is lower than the voltage of the common bus, and the difference is greater than the first preset threshold, then the battery pack will be subjected to voltage synchronization operation until the difference between the voltage of the lowest voltage pack and the voltage of the common bus meets the first voltage matching condition, and then it will be controlled to connect to the common bus through the charge and discharge control circuit to participate in charging.

[0082] Repeat the above process until all battery packs have completed parallel charging.

[0083] The first voltage matching condition is that the voltage difference is less than or equal to a first preset threshold.

[0084] This invention uses parallel voltage as the matching benchmark for subsequent battery pack connection. Combined with real-time voltage difference judgment and pre-charge control strategy, it realizes the step-by-step and optimal parallel connection of the remaining battery packs not connected to the common bus. For battery packs with low voltage, voltage synchronization operation is used to reduce the voltage difference, ensuring a smooth and controllable connection process, and effectively improving the energy coordination efficiency and thermal management performance of the multi-battery pack system.

[0085] When the BMS system detects a discharge request signal, it controls the battery pack with the highest voltage among the waiting battery packs to connect to the common bus through its charge and discharge control circuit to participate in the discharge. Then, the remaining waiting battery packs that are not connected to the common bus are connected to the common bus to participate in the discharge when the second voltage matching condition is met, so as to achieve parallel connection in stages until all battery packs have completed parallel discharge.

[0086] The remaining battery packs not yet connected to the common bus are sequentially connected to the common bus to participate in discharge when the second voltage matching condition is met, achieving step-by-step parallel connection until all battery packs have completed parallel discharge. Specifically:

[0087] The voltage difference between the voltage of the connected battery pack or the parallel voltage of multiple connected battery packs and the highest voltage among the remaining battery packs not connected to the common bus is monitored in real time. When the voltage difference is less than a second preset threshold, the highest voltage is controlled to connect to the common bus to participate in the discharge, realizing the step-by-step parallel connection until all battery packs have completed parallel discharge.

[0088] The charge / discharge control circuit is used to turn on or off the charging connection, discharging connection, and pre-charging connection between the corresponding battery pack and the common bus under the control of the BMS system.

[0089] The charge / discharge control circuit includes MOS switches or relays for turning on or off the charging connection, discharging connection, and pre-charge connection.

[0090] The charge / discharge control circuit specifically includes:

[0091] The first MOS switch, the second MOS switch, the third MOS switch, and the first resistor (i.e., the pre-charge resistor); wherein:

[0092] After the source of the first MOS switch is connected to the source of the third MOS switch, it is connected to the negative terminal of the corresponding battery pack. The gate of the first MOS switch is connected to the discharge control signal or the turn-off control signal issued by the BMS system, and the drain is connected to one end of the first resistor and then connected to the drain of the second MOS switch. The drain of the third MOS switch is connected to the other end of the first resistor, and the gate is connected to the pre-charge control signal or the turn-off control signal issued by the BMS system. The gate of the second MOS switch is connected to the charging control signal or the turn-off control signal, and the source is connected to the negative terminal of the common bus. The positive terminal of the battery pack is connected to the positive terminal of the common bus.

[0093] like Figure 1As shown in the figure, this embodiment illustrates a parallel connection structure of two battery packs, where BAT1 is battery pack 1 and BAT2 is battery pack 2. Each battery pack is connected to a common bus through a corresponding charge / discharge control circuit. The charge / discharge control circuit includes a charging MOS (i.e., the second MOS switch), a discharging MOS (i.e., the first MOS switch), a pre-charge MOS (i.e., the third MOS switch), and a pre-charge resistor R1 or R2 (with a resistance of 18Ω). In battery pack 1, the source of the discharging MOS is connected to the source of the pre-charge MOS and is connected to the negative terminal of BAT1. The gate of the discharging MOS receives the discharge control signal DISCHG_EN1 or the turn-off control signal from the BMS system, and its drain is connected to one end of the pre-charge resistor R1 and then connected to the drain of the charging MOS. The drain of the pre-charge MOS is connected to the other end of the pre-charge resistor R1, and its gate receives the pre-charge control signal PRECHG_EN1. The gate of the charging MOS receives the charging control signal CHG_EN1, and its source is connected to the negative terminal P- of the common bus. The positive terminal of BAT1 is directly connected to the positive terminal P+ of the common bus.

[0094] The structure of battery pack 2 is the same as that of battery pack 1. Correspondingly, CHG_EN2, DISCHG_EN2 and PRECHG_EN2 control the on / off state of its charging MOS, discharging MOS and pre-charge MOS, respectively, and its current limiting resistor is R2. The other connection methods are the same.

[0095] In this embodiment, to improve the response speed and stability of the pre-charge stage during hot-swapping of multiple battery packs, a fuzzy PID control algorithm is used to dynamically adjust the pre-charge current. Traditional fixed-value pre-charge resistors are difficult to balance the dual requirements of fast charging and surge current suppression: too small a resistance value can easily lead to excessive current, generating electromagnetic interference or even damaging the MOSFET; too large a resistance value results in excessively long pre-charge time, affecting the user experience.

[0096] To address this, the present invention uses a BMS system to collect in real time the difference (ΔV) between the common bus voltage and the battery pack voltage, the pre-charge current (I), and its rate of change, and inputs this data to a fuzzy PID controller to dynamically adjust the impedance characteristics of the pre-charge resistor. This controller uses fuzzy inference rules to identify the system state online. When the voltage difference is large, it automatically converts the system to a high-resistance state to limit the inrush current; when the voltage difference approaches zero, it gradually reduces the equivalent resistance to accelerate convergence. Simultaneously, the PID controller performs fine-tuning based on error signals to ensure that the pre-charge process is free of overshoot and oscillation.

[0097] This embodiment achieves adaptive, fast, and stable response in the pre-charging process by integrating fuzzy logic and classical control theory, significantly improving the electrical safety and energy utilization efficiency of multi-battery packs in dynamic access scenarios.

[0098] The voltage synchronization operation for the battery pack specifically involves:

[0099] Disconnect the second MOS switch corresponding to each battery pack that is charging, and turn on its third MOS switch;

[0100] Then the second MOS switch controlling the lower voltage battery pack is turned on to start charging;

[0101] When the voltage difference between the battery pack and the common bus voltage is less than or equal to the first preset threshold, the third MOS switch of each battery pack that is currently being charged is disconnected, and its second MOS switch is turned on to restore the charging connection and realize parallel charging of multiple battery packs.

[0102] In the pre-charge state: the third MOS switch is turned on based on the pre-charge control signal issued by the BMS system, and the first MOS switch and the second MOS switch are turned off; the current is current-limited to charge the capacitor on the common bus side through the third MOS switch and the first resistor, so that the common bus voltage gradually rises to be close to the voltage of the corresponding battery pack.

[0103] The control of exiting the pre-charge state and connecting to the common bus for charging via the charge and discharge control circuit is as follows: after the first voltage matching condition is met, the BMS system outputs a corresponding shutdown control signal to disconnect the third MOS switch and cut off the pre-charge connection; then, it outputs a charging control signal to turn on the second MOS switch, establishes a charging connection, and realizes stable connection of the battery pack to the common bus for charging.

[0104] In the discharged disconnected state: the first MOS switch, the second MOS switch and the third MOS switch are all in the disconnected state, and the charging and discharging path between the battery pack and the common bus is completely cut off, achieving electrical isolation.

[0105] The connection to the common bus for discharge specifically refers to:

[0106] The discharge control signal output by the BMS system turns on the first MOS switch to establish a discharge connection; if the third MOS switch is in the on state, it is simultaneously turned off to complete the stable connection of the battery pack to the common bus for discharge.

[0107] This invention is based on a hardware architecture of three MOS switches (discharge MOS, charge MOS, and precharge MOS). By precisely controlling the on / off timing of each MOS through a BMS system, it achieves physical isolation and safe switching between the charge / discharge and precharge circuits, replacing the traditional relay + fuse solution. This not only reduces system cost and size but also avoids problems such as oxidation and adhesion of mechanical contacts, significantly improving the response speed, repeatability, and long-term reliability of hot-swap operations.

[0108] Specifically:

[0109] Pre-charge mode: When battery pack 1 (BAT1) is not yet connected to the common bus, and its voltage is higher than the common bus voltage and the voltage difference is greater than the first preset threshold, it will enter pre-charge mode to avoid inrush current caused by direct conduction. At this time, the discharge MOS and charging MOS remain off, and the BMS system controls the pre-charge MOS to turn on. The current path is as follows:

[0110] BAT1+ → Common bus positive terminal (P+) → Common bus negative terminal (P-) → Body diode of charging MOS (flow from source S to drain D) → Precharge MOS (conducting state) → BAT1 negative terminal.

[0111] Through this path, the current slowly charges the capacitor on the common bus side via the current-limiting resistor (R1 in the figure), causing the bus voltage to gradually rise to close to the BAT1 voltage, thus completing the voltage pre-matching.

[0112] Charging Mode: After pre-charging is complete, the voltage difference between the bus voltage and BAT1 meets the set threshold. The BMS controls the charging MOS to turn on, while simultaneously turning off the pre-charging MOS, and the system enters normal charging mode. At this time, the external power supply charges BAT1 through the common bus, and the current path is as follows:

[0113] Common bus positive terminal (P+) → BAT1 positive terminal → BAT1 negative terminal → discharge MOSFET (source S to drain D, on state) → charging MOSFET (drain D to source S, on state) → common bus negative terminal (P-). Since the charging MOSFET is already on, its channel provides a low-resistance path, and the current no longer flows through the body diode, achieving efficient and low-loss charging.

[0114] Discharge Mode: When the system needs to supply power externally, the BMS controls the discharge MOS to turn on, and the battery pack enters discharge mode. The current path is as follows:

[0115] BAT1 positive terminal → Common bus positive terminal (P+) → External load → Common bus negative terminal (P-). At the P- node, the current first flows through the body diode of the charging MOS (from the source S to the drain D), and then through the discharging MOS (from the drain D to the source S, in the on state) back to the BAT1 negative terminal.

[0116] As the discharge MOSFET fully turns on, its channel on-resistance is much lower than the body diode voltage drop, and current gradually shifts to the discharge MOSFET channel, achieving low-loss discharge. This design avoids the conduction losses of the charging MOSFET in the discharge path, improving system efficiency.

[0117] It should be noted that, in this embodiment, the parallel voltage connected to the battery pack is determined by, as follows: Figure 2 The detection circuit shown detects, specifically:

[0118] This detection circuit is used to control and monitor the voltage level of the negative terminal (P-) of the common bus after the BMS system is powered on, to accurately sample the parallel voltage (PACK_VOLT) of the connected battery pack, and to ensure that the positive and negative terminals of the battery pack are not energized when the MOS transistor Q208 in the detection circuit is turned off, thus avoiding safety risks caused by residual voltage.

[0119] It should be noted that in a battery management system, whether the battery pack is connected to an external power source or load is mainly controlled by its internal power switching devices such as discharge MOS and charge MOS. However, even if these main switches are in the open state, if the voltage detection circuit is not designed properly, voltage may still be detected through the voltage divider resistor network (…). Figure 2 R230 and R231 in the circuit connect the negative terminal (P-) of the common bus to the system ground, causing the inactive battery pack to present a voltage to the outside through the common bus, i.e., "energized". This may cause safety risks such as electric shock, electric arc, or BMS misjudgment during hot-swapping operations.

[0120] To solve this problem, the present invention introduces a dedicated switching MOSFET into the detection circuit. Figure 2 Q208 (in the circuit) is used to control the on / off state of the detection path. This MOSFET is not part of the charge / discharge control circuit, but is located in the voltage sampling path. Its source is connected to the negative terminal (P-) of the common bus, and its drain is grounded through resistors R230 (2MΩ) and R231 (51kΩ). A "PACK_VOLT" signal is led out between the two resistors for voltage sampling. When the BMS system is not powered on or does not issue an enable signal (i.e., "P_ON / OFF" is low), the driving transistor Q207 is turned off, and the gate of Q208 is turned off due to the lack of driving voltage, thus completely isolating the negative terminal (P-) of the common bus from the voltage divider resistor network composed of R230 and R231.

[0121] In other words, when Q208 is disconnected, the detection circuit is isolated from the common bus, preventing the detection circuit from becoming a leakage path and ensuring that no voltage is presented to the outside through the detection circuit when the BMS system does not issue an enable signal (i.e., "P_ON / OFF").

[0122] Q207 turns on only when the BMS system powers on and outputs a high-level "P_ON / OFF" enable signal, driving Q208 to turn on. Only then is the voltage divider resistor network connected to the common bus, and sampling of the parallel voltage of the connected battery pack begins. This design, by adding a controlled switch Q208 at the voltage detection front end, achieves a safety mechanism of "only connecting the sampling circuit when the BMS is actively enabled," fundamentally avoiding the residual voltage problem caused by the constantly connected detection circuit during hot-swapping, and significantly improving the electrical safety and operational reliability of the system.

[0123] In summary, Figure 2The detection circuit shown achieves active management of the sampling path by introducing a controlled switch structure consisting of Q207 and Q208 at the front end of the voltage divider network. This circuit only activates the detection path after the BMS system issues a "P_ON / OFF" enable signal, allowing the PACK_VOLT signal to be sampled normally. When the BMS is not activated or the system is in standby mode, Q208 is turned off, completely isolating the electrical connection between the voltage divider network and the common bus, preventing minor leakage current or external voltage presentation caused by the resistive voltage divider circuit. This design ensures the safety and controllability of the voltage detection function, avoids the safety hazards of traditional normally-on sampling circuits in hot-swappable scenarios, and provides a fundamental guarantee for the reliable operation of multi-battery pack systems.

[0124] In this embodiment, the power-on process of the BMS system is controlled by the physical connection status of the battery pack. The BMS system only starts its internal main power supply and enters the working state when a stable voltage is detected at the positive terminal (P+) of the common bus. Afterward, the BMS system can perform voltage sampling, status judgment, and output corresponding MOS control signals (such as CHG_EN, DISCHG_EN, etc.). This design ensures that the BMS system only starts working after the battery pack is reliably connected, avoiding the risk of false start-up under abnormal conditions such as loose connections or improper installation.

[0125] The following is a detailed explanation of the hot-swappable charging process for multiple battery packs:

[0126] 1. Users can insert multiple new battery packs (physical connection) while an existing battery pack is charging.

[0127] 1.1 The new battery pack positive terminal (P+) is connected to the positive terminal of the common bus.

[0128] 1.2 At this time, none of the main circuit MOS (discharge MOS, charge MOS, precharge MOS) are turned on, and the new battery pack is not connected to the common bus.

[0129] 2. The BMS system detected a charging wake-up request signal from the charging pile.

[0130] 2.1 The charging pile sends a charging wake-up request signal through the communication or I / O port.

[0131] 2.2 The signal is received by the BMS system, triggering the system wake-up process.

[0132] 3. The BMS system verifies the in-situ status of the new battery pack.

[0133] 3.1 The BMS system detects the presence of voltage on P+ through its low-power wake-up pin, and preliminarily determines that the battery pack has been reliably inserted (i.e., it is in place).

[0134] 3.2 Allow the BMS system to start its internal main power supply (power on).

[0135] 3.3 When the “P_ON / OFF” signal is pulled high, it drives Q207 to turn on → Q208 to turn on.

[0136] 4. After powering on, the BMS performs system self-test and voltage acquisition.

[0137] 4.1 Collect voltage information of all battery packs in place and waiting.

[0138] If there are multiple battery packs waiting in place, proceed to the next step.

[0139] 5. Multi-battery pack voltage sorting and status preset (key step)

[0140] 5.1 Sort all battery packs in place and waiting in order of voltage value from low to high.

[0141] 5.2. Perform status judgment and locking on the remaining battery packs that are waiting in place, except for the battery pack with the lowest voltage:

[0142] If its voltage is greater than the common bus voltage and the voltage difference is greater than the first preset threshold, then control it to enter the pre-charge state and lock it.

[0143] If its voltage is higher than the common bus voltage and the voltage difference is less than or equal to the first preset threshold, or if its voltage is lower than or equal to the common bus voltage, it is controlled to enter the discharge disconnect state and locked.

[0144] Purpose: To prevent non-first-entry battery packs (i.e., the remaining battery packs waiting in place except the battery pack with the lowest voltage) from accidentally conducting before the bus voltage is established, thereby avoiding circulating current or surges.

[0145] 6. Connect the battery pack with the lowest control voltage to the charging port.

[0146] 6.1 Compare the difference between the battery pack voltage and the common bus voltage:

[0147] If the voltage of the battery pack with the lowest voltage is higher than the voltage of the common bus and the voltage difference between the two is greater than the first preset threshold:

[0148] →The BMS system sends a PRECHG_EN signal →The precharge MOS turns on.

[0149] →The current charges the bus capacitor through the pre-charging resistor, and the bus voltage gradually increases.

[0150] → Monitor the differential pressure in real time, and wait until it is less than or equal to the first preset threshold → pre-charging is complete.

[0151] If the voltage difference between the two is less than or equal to the first preset threshold:

[0152] →Skip the pre-charge and proceed directly to the next step.

[0153] If the voltage of the common bus is higher than the voltage of the battery pack with the lowest voltage, then the battery pack is subjected to voltage synchronization operation until the difference between the voltage of the battery pack with the lowest voltage and the voltage of the common bus meets the first voltage matching condition. Then, the battery pack is controlled to connect to the common bus through the charge and discharge control circuit to participate in charging.

[0154] 7. Connect and start charging.

[0155] →The BMS system sends a CHG_EN signal →The charging MOS turns on.

[0156] → Simultaneously disconnect the pre-charge MOS → Complete the switch from pre-charge to normal charging.

[0157] → An external power source provides stable charging to the battery pack via a common bus.

[0158] 8. Connect the remaining battery packs in parallel in stages.

[0159] 8.1. Real-time acquisition of the parallel voltage of the currently connected battery packs, i.e., the common bus voltage.

[0160] 8.2 Select the battery pack with the lowest voltage from the remaining unconnected battery packs as the battery pack to be connected, and compare whether the difference between its voltage and the common bus voltage meets the first voltage matching condition.

[0161] 8.3. Perform the corresponding operation based on the current status of the battery pack to be connected:

[0162] If the battery pack is in a pre-charge state:

[0163] If the voltage difference between it and the common bus voltage is less than or equal to the first preset threshold, then it is controlled to exit the pre-charge state, the charging MOS is turned on, and it is connected to the common bus to participate in charging.

[0164] If the condition is not met and the voltage is higher than the common bus voltage, the pre-charge state is maintained, and current-limited charging continues through the pre-charge resistor until the voltage difference meets the first voltage matching condition.

[0165] If the battery pack is in a discharged, disconnected state:

[0166] If the voltage difference between it and the parallel voltage is less than or equal to the first preset threshold, then its charging MOS is directly controlled to turn on and connected to the common bus to participate in charging.

[0167] If the pressure difference is greater than the first preset threshold:

[0168] When its voltage is higher than the common bus voltage, it is first controlled to enter the pre-charge state, and then charged by the pre-charge resistor with current limiting. After the voltage difference is ≤ the first preset threshold, it is then connected to the charging circuit.

[0169] When its voltage is lower than the common bus voltage, the battery pack is subjected to voltage synchronization operation until the difference between the voltage of the battery pack to be connected and the common bus voltage meets the first voltage matching condition, and then it is controlled to connect to the common bus through the charge and discharge control circuit to participate in charging.

[0170] 8.4 Repeat the above process, connecting the remaining battery packs one by one until all battery packs are fully charged in parallel.

[0171] In summary, this embodiment achieves safe, orderly, and shock-free access of multiple battery packs in hot-swappable scenarios through a collaborative control strategy of "in-situ status verification + voltage sorting + status preset + differential voltage matching + step-by-step parallel connection". It effectively avoids circulating current, arcing and protection malfunction caused by voltage mismatch, and significantly improves the reliability and energy utilization efficiency of the system.

[0172] When the present invention detects multiple battery packs waiting in the system, it acquires the real-time voltage of each battery pack and sorts them by voltage value. When the BMS system detects an external charging request signal, it controls the other battery packs waiting in the system (excluding the one with the lowest voltage) to enter a pre-charge state or a discharge disconnect state based on their voltage difference with the common bus, and locks this state. Subsequently, it prioritizes controlling the battery pack with the lowest voltage to connect to the common bus for charging when the first voltage matching condition is met. Then, it sequentially connects the remaining battery packs waiting in the system that are not connected to the common bus to participate in charging through their charging and discharging control circuits when the first voltage matching condition is met, realizing step-by-step parallel connection until all battery packs have completed parallel charging. When the BMS system detects a discharge request signal, it prioritizes controlling the battery pack waiting in the system with the highest voltage to connect to the common bus for discharging, and then sequentially connects the remaining battery packs waiting in the system when the second voltage matching condition is met, realizing step-by-step parallel discharging. Through the above-mentioned coordinated control, the orderly and shock-free parallel connection of multiple battery pack hot-swapping processes is realized, effectively avoiding problems such as circulating current, arcing and BMS false protection caused by voltage dispersion, and significantly improving the safety and operational stability of the system.

[0173] Example 2

[0174] To address the issues of circulating current surges, arcing risks, and connection timing disruptions caused by voltage differences during hot-swapping of multiple battery packs, this invention also proposes a dynamic hot-swapping collaborative control device for multiple battery packs. This device is applied to a multi-battery pack coordinated control system, which includes a common bus for connecting to an external power source or load; each battery pack is equipped with a charge / discharge control circuit; and each battery pack is connected to the common bus via its corresponding charge / discharge control circuit. The device includes:

[0175] The in-situ detection module is used to detect the number of all battery packs waiting in the multi-battery pack coordination control system when the BMS system detects a charging wake-up request signal or a discharging request signal while the battery pack is in a charging or discharging state. If there are multiple in-situ waiting battery packs, the module obtains the real-time voltage of each in-situ waiting battery pack and sorts them by voltage value. The in-situ waiting battery packs are those that have completed physical insertion but have not been connected to the common bus.

[0176] The charging control module, when the BMS system detects a charging wake-up request signal, performs corresponding operations based on the voltage relationship between the battery packs (excluding the one with the lowest voltage) and the common bus for the other battery packs waiting in place.

[0177] If its voltage is higher than the common bus voltage and the voltage difference is greater than the first preset threshold, its charging and discharging control circuit is controlled to enter the pre-charging state and locked in this state; if its voltage is higher than the common bus voltage and the voltage difference is less than or equal to the first preset threshold, or its voltage is lower than or equal to the common bus voltage, its charging and discharging control circuit is controlled to be in the discharging disconnect state and locked in this state; the battery pack with the lowest control voltage is connected to the common bus to participate in charging through its charging and discharging control circuit when the first voltage matching condition is met; the battery packs not connected to the common bus are connected to the common bus to participate in charging through their charging and discharging control circuits when the first voltage matching condition is met, so as to achieve parallel connection in stages until all battery packs are connected in parallel for charging.

[0178] The discharge control module is used to control the battery pack with the highest voltage among the waiting battery packs to connect to the common bus through its charge and discharge control circuit when the BMS system detects a discharge request signal. Then, the remaining waiting battery packs that are not connected to the common bus are connected to the common bus to participate in the discharge when the second voltage matching condition is met, so as to realize the parallel connection in stages until all battery packs have completed the parallel discharge.

[0179] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0180] Furthermore, in this invention, descriptions involving terms such as "first," "second," and "a" are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0181] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0182] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

Claims

1. A method for dynamic hot-swappable collaborative control of multiple battery packs, characterized in that, An application in a multi-battery pack coordinated control system, the system including a common bus for connecting to an external power source or load; each battery pack is equipped with a charge / discharge control circuit; each battery pack is connected to the common bus through its corresponding charge / discharge control circuit; the method includes: When the battery pack is in a charging or discharging state, the BMS system detects a charging wake-up request signal or a discharging request signal, and then detects the number of all battery packs waiting in place in the multi-battery pack coordination control system. If there are multiple battery packs waiting in place, the system obtains the real-time voltage of each battery pack waiting in place and sorts them by voltage value. The battery packs waiting in place are those that have been physically inserted but have not been connected to the common bus. When the BMS system detects a charging wake-up request signal, for the battery packs waiting in place, excluding the battery pack with the lowest voltage, the corresponding operation is performed based on their voltage relationship with the common bus: If its voltage is higher than the common bus voltage and the voltage difference is greater than the first preset threshold, its charging and discharging control circuit is controlled to enter the pre-charging state and locked in this state; if its voltage is higher than the common bus voltage and the voltage difference is less than or equal to the first preset threshold, or its voltage is lower than or equal to the common bus voltage, its charging and discharging control circuit is controlled to be in the discharging disconnect state and locked in this state; the battery pack with the lowest control voltage is connected to the common bus to participate in charging through its charging and discharging control circuit when the first voltage matching condition is met; the battery packs not connected to the common bus are connected to the common bus to participate in charging through their charging and discharging control circuits when the first voltage matching condition is met, so as to achieve parallel connection in stages until all battery packs are connected in parallel for charging. When the BMS system detects a discharge request signal, it controls the battery pack with the highest voltage among the waiting battery packs to connect to the common bus through its charge and discharge control circuit to participate in the discharge. Then, the remaining waiting battery packs that are not connected to the common bus are connected to the common bus to participate in the discharge when the second voltage matching condition is met, so as to achieve parallel connection in stages until all battery packs have completed parallel discharge.

2. The multi-battery pack dynamic hot-swap collaborative control method according to claim 1, characterized in that, When the first voltage matching condition is met, the battery pack with the lowest control voltage is connected to the common bus for charging via its charge / discharge control circuit, specifically: If the voltage of the battery pack with the lowest voltage is higher than the voltage of the common bus and the voltage difference between the two is greater than the first preset threshold, then the battery pack is controlled to enter the pre-charge state. After the voltage difference between the battery pack and the common bus meets the first voltage matching condition, the battery pack is controlled to connect to the common bus through the charge and discharge control circuit to participate in charging. If the voltage difference between the two meets the first voltage matching condition, the battery pack is directly controlled to connect to the common bus for charging through the charge and discharge control circuit. If the voltage of the common bus is higher than the voltage of the battery pack with the lowest voltage, then the battery pack is subjected to voltage synchronization operation until the difference between the voltage of the battery pack with the lowest voltage and the voltage of the common bus meets the first voltage matching condition. Then, the battery pack is controlled to connect to the common bus through the charge and discharge control circuit to participate in charging.

3. The multi-battery pack dynamic hot-swap collaborative control method according to claim 1, characterized in that, The process involves sequentially connecting battery packs not currently connected to the common bus to participate in charging via a charge / discharge control circuit when the first voltage matching condition is met, achieving step-by-step parallel connection until all battery packs have completed parallel charging; specifically: The system continuously monitors the parallel voltage of currently connected battery packs (i.e., the common bus voltage) and compares it with the lowest voltage among the remaining battery packs not connected to the common bus. Based on the comparison result and the current state of the battery pack with the lowest voltage, the system performs the corresponding operation: For a battery pack in the pre-charge state, if the voltage difference between it and the common bus voltage meets the first voltage matching condition, it is controlled to exit the pre-charge state and connected to the common bus to participate in charging through the charge and discharge control circuit; if it does not meet the condition and its voltage is higher than the common bus voltage, the pre-charge state is maintained until the condition is met. For a battery pack in the discharge disconnected state, if the voltage difference between it and the common bus voltage meets the first voltage matching condition, it is directly controlled to connect to the common bus through the charge and discharge control circuit to participate in charging. If the voltage of the battery pack with the lowest voltage is lower than the voltage of the common bus, and the difference is greater than the first preset threshold, then the battery pack will be subjected to voltage synchronization operation until the difference between the voltage of the lowest voltage pack and the voltage of the common bus meets the first voltage matching condition, and then it will be controlled to connect to the common bus through the charge and discharge control circuit to participate in charging. Repeat the above process until all battery packs have completed parallel charging.

4. The multi-battery pack dynamic hot-swap collaborative control method according to claim 1, characterized in that, The remaining battery packs not yet connected to the common bus are sequentially connected to the common bus to participate in discharge when the second voltage matching condition is met, achieving step-by-step parallel connection until all battery packs have completed parallel discharge. Specifically: The voltage difference between the voltage of the connected battery pack or the parallel voltage of multiple connected battery packs and the highest voltage among the remaining battery packs not connected to the common bus is monitored in real time. When the voltage difference is less than a second preset threshold, the highest voltage is controlled to connect to the common bus to participate in the discharge, realizing the step-by-step parallel connection until all battery packs have completed parallel discharge.

5. The multi-battery pack dynamic hot-swap collaborative control method according to claim 1, characterized in that, The system detects the number of all battery packs waiting in place within the multi-battery pack coordination control system. If only one battery pack exists, then: When the BMS system detects a charging wake-up request signal, perform the following operations: If the voltage of the battery pack waiting in place is higher than the voltage of the common bus and the voltage difference between the two is greater than the first preset threshold, the battery pack is controlled to enter the pre-charge state. After the voltage difference between the battery pack and the common bus meets the first voltage matching condition, the battery pack is controlled to connect to the common bus for charging through the charge and discharge control circuit. If the voltage difference between the two meets the first voltage matching condition, the battery pack is directly controlled to be connected to the common bus for charging through the charge and discharge control circuit. If the voltage of the battery pack waiting in place is lower than the voltage of the common bus and the difference is greater than the first preset threshold, then the battery pack is subjected to voltage synchronization operation until the difference between the voltage of the battery pack and the voltage of the common bus meets the first voltage matching condition, and then it is controlled to connect to the common bus through the charge and discharge control circuit to participate in charging. When the BMS system detects a discharge request signal, perform the following operations: The battery pack in place is connected to the common bus to participate in the discharge through its charge and discharge control circuit.

6. The multi-battery pack dynamic hot-swap collaborative control method according to claim 3, characterized in that, The charge / discharge control circuit is used to turn on or off the charging connection, discharging connection, and pre-charging connection between the corresponding battery pack and the common bus under the control of the BMS system.

7. The multi-battery pack dynamic hot-swap collaborative control method according to claim 6, characterized in that, The charge / discharge control circuit includes MOS switches or relays for turning on or off the charging connection, discharging connection, and pre-charge connection.

8. The multi-battery pack dynamic hot-swap collaborative control method according to claim 7, characterized in that, The charge / discharge control circuit specifically includes: The system comprises a first MOS switch, a second MOS switch, a third MOS switch, and a first resistor; wherein: After the source of the first MOS switch is connected to the source of the third MOS switch, it is connected to the negative terminal of the corresponding battery pack. The gate of the first MOS switch is connected to the discharge control signal or turn-off control signal issued by the BMS system, and the drain is connected to one end of the first resistor and then connected to the drain of the second MOS switch. The drain of the third MOS switch is connected to the other end of the first resistor, and the gate is connected to the pre-charge control signal or turn-off control signal issued by the BMS system. The gate of the second MOS switch is connected to the charging control signal or turn-off control signal, and the source is connected to the negative terminal of the common bus. The positive terminal of the battery pack is connected to the positive terminal of the common bus.

9. A multi-battery pack dynamic hot-swap collaborative control method according to claim 8, characterized in that, In the pre-charge state: the third MOS switch is turned on based on the pre-charge control signal issued by the BMS system, and the first MOS switch and the second MOS switch are turned off; the current is current-limited to charge the capacitor on the common bus side through the third MOS switch and the first resistor, so that the common bus voltage gradually rises to be close to the voltage of the corresponding battery pack. The control of exiting the pre-charge state and connecting to the common bus for charging via the charge and discharge control circuit is as follows: after the first voltage matching condition is met, the BMS system outputs a corresponding shutdown control signal to disconnect the third MOS switch and cut off the pre-charge connection; then, it outputs a charging control signal to turn on the second MOS switch, establishes a charging connection, and realizes stable connection of the battery pack to the common bus for charging. In the discharged disconnected state: the first MOS switch, the second MOS switch and the third MOS switch are all in the disconnected state, and the charging and discharging path between the battery pack and the common bus is completely cut off, achieving electrical isolation.

10. The multi-battery pack dynamic hot-swap collaborative control method according to claim 8, characterized in that, The connection to the common bus for discharge specifically refers to: The discharge control signal output by the BMS system turns on the first MOS switch to establish a discharge connection; if the third MOS switch is in the on state, it is simultaneously turned off to complete the stable connection of the battery pack to the common bus for discharge.

11. The multi-battery pack dynamic hot-swap collaborative control method according to claim 9, characterized in that, The first voltage matching condition is that the voltage difference is less than or equal to a first preset threshold. The voltage synchronization operation for the battery pack specifically involves: Disconnect the second MOS switch corresponding to each battery pack that is charging, and turn on its third MOS switch; Then the second MOS switch controlling the lower voltage battery pack is turned on to start charging; When the voltage difference between the battery pack and the common bus voltage is less than or equal to the first preset threshold, the third MOS switch of each battery pack that is currently being charged is disconnected, and its second MOS switch is turned on to restore the charging connection and realize parallel charging of multiple battery packs.

12. A multi-battery pack dynamic hot-swap collaborative control device, characterized in that, An application in a multi-battery pack coordinated control system, the system including a common bus for connecting to an external power source or load; each battery pack is equipped with a charge / discharge control circuit; each battery pack is connected to the common bus through its corresponding charge / discharge control circuit; the device includes: The in-situ detection module is used to detect the number of all battery packs waiting in the multi-battery pack coordination control system when the BMS system detects a charging wake-up request signal or a discharging request signal while the battery pack is in a charging or discharging state. If there are multiple in-situ waiting battery packs, the module obtains the real-time voltage of each in-situ waiting battery pack and sorts them by voltage value. The in-situ waiting battery packs are those that have completed physical insertion but have not been connected to the common bus. The charging control module, when the BMS system detects a charging wake-up request signal, performs corresponding operations based on the voltage relationship between the battery packs (excluding the one with the lowest voltage) and the common bus for the other battery packs waiting in place. If its voltage is higher than the common bus voltage and the voltage difference is greater than the first preset threshold, its charging and discharging control circuit is controlled to enter the pre-charging state and locked in this state; if its voltage is higher than the common bus voltage and the voltage difference is less than or equal to the first preset threshold, or its voltage is lower than or equal to the common bus voltage, its charging and discharging control circuit is controlled to be in the discharging disconnect state and locked in this state; the battery pack with the lowest control voltage is connected to the common bus to participate in charging through its charging and discharging control circuit when the first voltage matching condition is met; the battery packs not connected to the common bus are connected to the common bus to participate in charging through their charging and discharging control circuits when the first voltage matching condition is met, so as to achieve parallel connection in stages until all battery packs are connected in parallel for charging. The discharge control module is used to control the battery pack with the highest voltage among the waiting battery packs to connect to the common bus through its charge and discharge control circuit when the BMS system detects a discharge request signal. Then, the remaining waiting battery packs that are not connected to the common bus are connected to the common bus to participate in the discharge when the second voltage matching condition is met, so as to realize the parallel connection in stages until all battery packs have completed the parallel discharge.

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