A battery system, a battery system charging control method and device

Abstract

The application discloses a battery system, a battery system charging control method and device, and relates to the technical field of battery systems. The battery system charging control method comprises the following steps: for any battery module in a battery system, when the battery module is in a constant-current charging state, a charge balance enabling signal of the battery module is acquired; when the charge balance enabling signal meets a preset condition, a charge compensation value corresponding to the battery module is acquired; an expected charging current value of the battery module is obtained according to the charge compensation value; and a duty cycle of the power converter when the power converter is used to charge the battery module in a constant-current mode is obtained according to the expected charging current value. Therefore, one power converter can be used to control the charge balance of all battery modules in a constant-current charging state in the battery system. When the number of battery modules in the battery system is large, multiple battery modules can be connected to a power supply through one power converter, so that the cost of the battery system is reduced.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and specifically to a battery system, a battery system charging control method, and a device. Background Technology

[0002] Over the past 20 years, battery systems have developed rapidly and are now widely used in electronic devices across various industries, such as electric vehicles, consumer electronics (e.g., mobile phones, laptops, smartwatches), smart grids, energy storage systems, and medical devices. In a battery system, a large number of battery cells are connected in series or parallel to form a high-power battery module or battery pack.

[0003] However, due to factors such as manufacturing processes, operating environments, and battery health, the characteristics of different batteries will vary over time. For example, the internal resistance of a battery changes with its lifespan and ambient temperature, thus affecting its output voltage. During charging and discharging, these differences will manifest as variations in the battery's state of charge (SOC). If charge imbalance is not effectively controlled, the battery system may experience overcharging or over-discharging, reducing the overall charging and discharging efficiency of the battery system and consequently affecting the safe and stable operation of the system.

[0004] Therefore, given the differences in battery characteristics and operating environments, achieving balanced control of different battery cells or modules is a crucial factor in ensuring the efficient, safe, and effective operation of battery systems.

[0005] Existing battery charge balancing methods can be broadly categorized into two types: passive balancing and active balancing. Traditional passive balancing utilizes parallel resistors to dissipate excess energy from the battery through resistor heating. This method is simple to control, but its balancing current is very small, typically only tens to hundreds of milliamps, thus requiring a long balancing time. Furthermore, resistor heat dissipation not only reduces energy conversion efficiency but also places higher demands on the system's heat dissipation. In contrast to passive balancing, active balancing utilizes components and devices such as inductors, capacitors, or power converters / inverters to achieve active balancing by transferring battery energy or directly controlling the battery's charge and discharge rates. Among these, the power converter, as an essential component for battery charge and discharge control, only requires the addition of a balancing control algorithm, without the need for additional hardware circuitry, to achieve battery system balancing control. Therefore, using power converters to achieve active battery balancing has received increasing attention.

[0006] Currently, in common methods, each battery pack is connected to a power converter to achieve charge / discharge control and balance control. For example... Figure 1 As shown, to achieve traditional battery charging (such as the battery charging process during capacity formation), multiple single-input single-output power converters are required to control the charging current and voltage of each battery. When the number of batteries in the system increases significantly, the corresponding number of power converters also increases, putting considerable pressure on the system's design cost. Especially when the number of battery modules reaches hundreds or thousands, reducing the cost of the power converters becomes a pressing issue. Summary of the Invention

[0007] In view of this, embodiments of the present invention provide a battery system, a battery system charging control method and apparatus to solve the problem of high cost of power converter when the number of battery modules is large.

[0008] According to a first aspect, embodiments of the present invention provide a battery system charging control method, the battery system including multiple battery modules, the multiple battery modules being connected to a power source via a power converter, the battery system charging control method including: for any battery module, when the battery module is in a constant current charging state, acquiring a charge balance enable signal of the battery module; when the charge balance enable signal meets a preset condition, acquiring a charge compensation value corresponding to the battery module; obtaining an expected charging current value of the battery module based on the charge compensation value; and obtaining the duty cycle of the power converter when the battery module is being charged at a constant current based on the expected charging current value.

[0009] In the battery system charging control method provided in this embodiment of the invention, for any battery module in the battery system, when the battery module is in a constant current charging state, the charge balance enable signal of the battery module is acquired; when the charge balance enable signal meets a preset condition, the charge compensation value corresponding to the battery module is acquired; the expected charging current value of the battery module is obtained based on the charge compensation value; and the duty cycle of the power converter when the battery module is being charged at constant current is obtained based on the expected charging current value. Thus, a single power converter can be used to perform charge balance control on all battery modules in the battery system that are in a constant current charging state. When there are many battery modules in the battery system, multiple battery modules can be connected to the power supply through a single power converter, replacing the existing scheme where each battery module is connected to a separate power converter, thereby reducing the cost of the battery system.

[0010] In conjunction with the first aspect, in the first embodiment of the first aspect, obtaining the expected charging current value of the battery module based on the charge compensation value includes: obtaining a constant current charging reference value of the battery module; and multiplying the charge compensation value by the constant current charging reference value to obtain the expected charging current value of the battery module.

[0011] In conjunction with the first aspect, in the second embodiment of the first aspect, obtaining the duty cycle of the power converter when charging the battery module at constant current based on the expected charging current value includes: acquiring the measured charging current value of the battery module; and obtaining the duty cycle of the power converter when charging the battery module at constant current based on the expected charging current value and the measured charging current value.

[0012] In conjunction with the first aspect, in the third embodiment of the first aspect, before obtaining the charge compensation value corresponding to the battery module, the method further includes: obtaining the actual charge value and the charge reference value of the battery module respectively; and obtaining the charge compensation value based on the actual charge value and the charge reference value.

[0013] In conjunction with the third embodiment of the first aspect, in the fourth embodiment of the first aspect, before obtaining the charge reference value of the battery module, the method further includes: determining the charging mode of each battery module in the battery system whose charge balance enable signal meets preset conditions; obtaining the actual charge value of each battery module in the battery system whose charge balance enable signal meets preset conditions and is in constant current charging mode; calculating the average value of the actual charge values ​​of all battery modules in the battery system whose charge balance enable signal meets preset conditions and is in constant current charging mode, and using the average value as the charge reference value.

[0014] In conjunction with the first aspect, in the fifth embodiment of the first aspect, before acquiring the charge balance enable signal of the battery module, the method further includes: acquiring the voltage of the battery module; determining whether the voltage has reached a preset first threshold; when the voltage has not reached the first threshold, determining that the battery module is in a constant current charging mode; when the voltage has reached the first threshold, determining that the battery module is in a constant voltage charging mode.

[0015] In conjunction with the first aspect, in the sixth embodiment of the first aspect, before obtaining the duty cycle of the power converter when it is constantly charging the battery module based on the expected value of the charging current, the method further includes: obtaining the state of the battery-side switch; and determining whether the power converter is constantly charging the battery module based on the state of the battery-side switch.

[0016] In conjunction with the first aspect, in the seventh embodiment of the first aspect, the battery charging control method further includes: when the battery module is in a constant voltage charging state, acquiring a voltage reference value and the actual voltage value of the battery module respectively; and obtaining the duty cycle of the power converter for constant voltage charging of the battery module based on the voltage reference value and the actual voltage value.

[0017] According to a second aspect, embodiments of the present invention provide a battery charging control device. The battery system includes multiple battery modules, which are connected to a power source via a power converter. The battery charging control method includes a first acquisition module, a second acquisition module, a compensation module, and an adjustment module. Specifically, for any battery module, when the battery module is in a constant current charging state, the first acquisition module is used to acquire the charge balance enable signal of the battery module; when the charge balance enable signal meets a preset condition, the second acquisition module is used to acquire a charge compensation value corresponding to the battery module; the compensation module is used to obtain the expected charging current value of the battery module based on the charge compensation value; and the adjustment module is used to obtain the duty cycle of the power converter when the battery module is being charged at a constant current based on the expected charging current value.

[0018] According to a third aspect, embodiments of the present invention also provide a battery system, including a power supply side circuit module, a battery side circuit module, and a controller module. The controller module includes a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to perform the battery system charging control method described in the first aspect or any embodiment of the first aspect. Attached Figure Description

[0019] The features and advantages of the invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the drawings:

[0020] Figure 1 This is a block diagram of a battery system in the prior art;

[0021] Figure 2 This is a schematic diagram of the battery system in Embodiment 1 of the present invention;

[0022] Figure 3 This is a schematic diagram of an example of a single-input multiple-output power converter battery system.

[0023] Figure 4 This is a schematic diagram of a back-to-back switch using an N-type MOSFET as an example;

[0024] Figure 5This is a schematic flowchart of the battery system charging control method in Embodiment 1 of the present invention;

[0025] Figure 6 This is a timing diagram for circuit control;

[0026] Figure 7 The control block diagram for charge balance control and constant current control;

[0027] Figure 8 A control block diagram for a battery system in a constant voltage charging state;

[0028] Figure 9 A schematic diagram of the control flow during battery system charging;

[0029] Figure 10 This is a schematic diagram of the battery system charging control device in Embodiment 2 of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] Embodiment 1 of the present invention provides a battery system charging control method. The battery system includes multiple battery modules, which are connected to a power source via a power converter. Figure 2 As shown, battery module 1, battery module 2 and battery module 3 are all connected to a bidirectional switching power supply through a single-input multiple-output power converter.

[0033] For example, in Embodiment 1 of the present invention, the battery module can be a single battery cell or multiple single battery cells connected in parallel.

[0034] Figure 3 Here is a circuit example of a single-input multiple-output battery system, such as Figure 3 As shown, the entire system can be divided into three main modules: the power supply side circuit module, the battery side circuit module, and the controller module (including the algorithm). The power supply side circuit module is a DC-DC power converter. It uses the drive signal Pconv to control the on / off state of two switches, Su and Sl, to adjust the duty cycle of the power converter, thereby regulating the voltage and current during battery charging and achieving charge balance between batteries. It should be noted that... Figure 3The medium-power converter is a non-isolated buck / boost converter. If other topologies of converters are used, such as isolated flyback converters or forward converters, it will not affect the system's functionality or controller algorithm design.

[0035] The battery-side circuit module is a switch for multiple batteries via bidirectional conduction, such as a back-to-back MOSFET switch. 11 ,S 12 ),(S 21 ,S 22 ),….,and(S N1 ,S N2 These MOSFETs are coupled together to achieve time-sharing control in different paths. The back-to-back MOSFET structure is primarily used to achieve bidirectional energy flow and control. Specifically, for example... Figure 4 As shown, the right end of the inductor L on the power supply side and the MOSFET switch S on the battery side... 12 ,S 22 …,S N2 The drain and the battery-side input capacitor C 12 C 22 …,C N2 They are coupled together. Between each battery and the coupling point, there is a set of back-to-back MOSFET switches. The sources of the two MOSFETs are connected together, and their gates receive the same control signal to achieve bidirectional energy flow and control.

[0036] The controller module mainly includes control circuitry and algorithms. This module acquires battery-side current and voltage (V1, V2, ..., V...). N ;I1,I2,…,I N ) and power supply side current and voltage (V in ,I in This information is transmitted to the controller, and the controller signals (P1, P2, ..., P) are output. N ,P conv ).

[0037] In other words, the single-input power converter on the power supply side is coupled to multiple output battery paths, and multiple paths are coupled to one end of the inductor to provide power / energy to multiple batteries via the output port, including back-to-back switches for bidirectional battery energy transfer; and a control circuit connected to the input power supply side power converter switch and the output battery side switch.

[0038] Figure 5 This is a schematic flowchart of the battery system charging control method in Embodiment 1 of the present invention, as shown below. Figure 5 As shown, the battery system charging control method includes the following steps:

[0039] S101: For any battery module, when the battery module is in a constant current charging state, acquire the charge balance enable signal of the battery module.

[0040] In Embodiment 1 of this invention, the charge balance enable signal can be determined based on the health status of the battery module. For example, the charge balance enable signal can be represented by 1 and 0. For instance, when the charge balance enable signal is 1, it indicates that the battery module is healthy and meets the conditions for charge balancing; when the charge balance enable signal is 0, it indicates that the battery module is unhealthy and does not meet the conditions for charge balancing. Therefore, the charge balancing function can be switched in or out of the system based on the charge balance enable signal, making the system operation more flexible. For example, when the charge balance enable signal is 1, the system is in operation; when the charge balance enable signal is 0, the system is out of operation.

[0041] Furthermore, before acquiring the charge balance enable signal of the battery module, the method further includes: determining whether the battery module is in constant current charging mode. Specifically, determining whether the battery module is in constant current charging mode can be achieved by: acquiring the voltage of the battery module; determining whether the voltage has reached a preset first threshold; when the voltage has not reached the first threshold, determining that the battery module is in constant current charging mode; when the voltage has reached the first threshold, determining that the battery module is in constant voltage charging mode. That is, before the acquired charge balance enable signal meets the preset condition, it is first determined whether the battery module is in constant current charging state or constant voltage charging state. This is because charge balance control requires adjusting the current charging rate of the battery, and the current is difficult to control during constant voltage charging, so the charge balance function is turned off (not enabled) during constant voltage charging. Therefore, only when the battery module is in constant current charging mode will the step of acquiring the charge balance enable signal of the battery module in step S101 be executed, thereby realizing charge balance control.

[0042] S102: When the charge balance enable signal meets the preset conditions, obtain the charge compensation value corresponding to the battery module.

[0043] Specifically, the condition that the charge balance enable signal meets the preset conditions can be understood as: the battery module is in a healthy state based on the charge balance enable signal. For example, the condition that the charge balance enable signal meets the preset conditions can be understood as: whether the charge balance enable signal is 1. When it is 1, the charge balance enable signal is considered to meet the preset conditions; when it is 0, the charge balance enable signal is considered not to meet the preset conditions.

[0044] As a further implementation, before obtaining the charge compensation value corresponding to the battery module, the method further includes: obtaining the actual charge value and the charge reference value of the battery module respectively; and obtaining the charge compensation value based on the actual charge value and the charge reference value.

[0045] Specifically, the charge compensation value can be obtained based on the charge reference value and the actual charge value of the battery module as follows: calculate a first difference between the charge reference value and the actual charge value, and then use a preset first control method to obtain the charge compensation value based on the first difference. For example, the first control method includes, but is not limited to, PI (proportional integral controller) control and predictive control. For example, the first difference can be used as the input to the charge compensator, which can employ PI control or predictive control methods.

[0046] Furthermore, before obtaining the charge reference value of the battery module, the method further includes: determining the charging mode of each battery module in the battery system where the charge balance enable signal meets a preset condition (e.g., the charge balance enable signal is 1); obtaining the actual charge value of each battery module in the battery system where the charge balance enable signal meets the preset condition and is in constant current charging mode; calculating the average value of the actual charge values ​​of all battery modules in the battery system where the charge balance enable signal meets the preset condition and is in constant current charging mode, and using the average value as the charge reference value.

[0047] Specifically, the average value of the actual charge of all battery modules in the battery system that meet the preset conditions for the charge balance enable signal and are in constant current charging mode can be calculated using the following formula (1):

[0048]

[0049] In Formula 1 above, SOC ref The SOC1, SOC2, and SOC3 values ​​represent the reference charge values, while the actual charge values ​​are SOC1, SOC2, and SOC3. This indicates that the battery module is connected to the system. Specifically, when the battery module is connected to the system (the charge balance enable signal meets the preset conditions and is not short-circuited) and is in a constant current charging state, The value is 1; when the battery module is not connected to the system (i.e., the charge balance enable signal does not meet the preset conditions) or when the battery module is connected to the system but is in a constant voltage charging state. The value is 0.

[0050] S103: Obtain the expected charging current value of the battery module based on the charge compensation value.

[0051] As a specific implementation method, the expected charging current value of the battery module can be obtained based on the charge compensation value as follows: obtain the constant current charging reference value of the battery module; multiply the charge compensation value by the constant current charging reference value to obtain the expected charging current value of the battery module.

[0052] S104: Based on the expected value of the charging current, obtain the duty cycle of the power converter when charging the battery module at a constant current.

[0053] As a specific implementation method, the duty cycle of the power converter when charging the battery module at constant current can be obtained based on the expected charging current value as follows: obtain the measured charging current value of the battery module; and obtain the duty cycle of the power converter when charging the battery module at constant current based on the expected charging current value and the measured charging current value.

[0054] Specifically, the duty cycle of the power converter during constant current charging of the battery module can be obtained based on the expected charging current and the measured charging current, as follows: Calculate the second difference between the expected charging current and the measured charging current, and then use this second difference to control the power converter using a preset second control method to obtain the duty cycle of the power converter during constant current charging of the battery module. For example, the second control method includes, but is not limited to, PI (proportional integral controller) control and predictive control. For example, the second difference can be used as the input to a current compensator, which can employ PI control or predictive control methods.

[0055] As a specific implementation method, the battery system charging control method of Embodiment 1 of the present invention further includes: controlling only one battery module to be connected to the power converter at any given time. That is, time-division multiplexing is used to achieve decoupling control between the battery module and the power converter.

[0056] Specifically, Figure 6 This is a timing diagram for circuit control. It can be seen that the switching frequency on the battery side is much lower than the switching frequency on the power supply side. Within one cycle T0, the time length for each battery on the battery side to be connected to the system is T0 / N, i.e., as shown... Figure 6 As shown, battery #1 is connected to the power converter during time period T1, battery #2 during time period T2, and battery #3 during time period T3. During time periods T1, T2, ..., T3, the power converter on the power supply side operates at duty cycles D1, D2, ..., D... NThis enables control of the charging voltage or charging current of the corresponding battery path. During the path switching process (e.g., from battery #1 being turned on and battery #2 being turned off to battery #1 being turned off and battery #2 being turned on), the controller outputs a short dead time Td. During this time, all control signals are not activated. This is to prevent battery short circuits caused by both batteries being turned on simultaneously.

[0057] Example, combination Figure 3 Within one cycle T0, when battery #1 needs to be connected to the power converter, the power supply side switch (S) 11 ,S 12 ) is on, other switches (S) 21 ,S 22 ),…,(S N1 ,S N2 The power supply side switch (S) is closed, with a conduction time of T1; when battery #2 needs to be connected to the power converter, the power supply side switch (S) is closed. 21 ,S 22 ) is on, other switches (S) 11 ,S 12 ),…,(S N1 ,S N2 The power supply side switch (S) is closed, with a conduction time of T2; when battery #N needs to be connected to the power converter, the power supply side switch (S) is closed. N1 ,S N2 ) is on, other switches (S) 11 ,S 12 ),(S 21 ,S 22 ..., Closed, conduction time is T N In this way, only one battery is connected to the power source at any given time, achieving the purpose of time-sharing multiplexing.

[0058] Furthermore, after obtaining the duty cycle of the power converter when it is constantly charging the battery module based on the expected charging current, the method further includes: obtaining the state of the battery module switch; determining whether the power converter is connected to the battery module based on the state of the battery module switch; and controlling the constant current charging of the battery module using the duty cycle when the power converter is connected to the battery module. In other words, constant current charging control of the battery module is only performed using the duty cycle when the power converter is constantly charging the battery module.

[0059] Therefore, although multiple battery modules in the battery system of Embodiment 1 of this invention are connected to the power supply through a single power converter, at any given time, the power converter is only connected to the battery module whose switch is in the open state, and only one battery module's switch is in the open state at any given time. Thus, during the constant current charging period, the power converter can be connected to different battery modules, using different duty cycles for constant current charging control. This allows for charge balance control of all battery modules in the constant current charging state using a single power converter. When the number of battery modules in the battery system is large, multiple battery modules can be connected to the power supply through a single power converter, replacing the existing approach where each battery module is connected to a separate power converter, thereby reducing the cost of the battery system. As a further implementation, after obtaining the duty cycle of the power converter for constant current charging of the battery module based on the expected charging current value, the method further includes adjusting the last one or the last few duty cycles to 0. This ensures that after the next battery module is connected, the inductor current changes from the initial OA value, preventing system instability caused by residual energy from the previous cycle. Specifically, before switching paths, the duty cycle of the power switch is set to 0 in the last one or the last few cycles, such as... Figure 6 As shown in the switch diagram in the fourth row, before switching the circuit, the inductor is no longer connected to the power supply, and the energy inside gradually becomes 0.

[0060] In other words, in Embodiment 1 of this invention, multiple battery modules are connected to the power supply through a single power converter. To address the coupling issue between different paths, time-division multiplexing decoupling control is used. Simply put, by controlling the on / off state of the battery-side switch, only one path is connected to the power converter on the power supply side at any given time. Furthermore, during path switching, the current in inductor L is kept zero, thus avoiding disturbances caused by residual energy in the inductor during path switching.

[0061] The following is combined with Figure 7 An example of charge balancing and constant current control is given. After completing the decoupling control of the multiple output paths of the battery, the controller also needs to be able to perform constant current charging, constant voltage charging, and charge balancing control between different batteries for each battery. Among them, charge balancing control requires adjusting the battery's current charging rate, but the current is difficult to control during constant voltage charging. Therefore, the charge balancing function is turned off (disabled) during constant voltage charging. Figure 7 This is a control block diagram for charge balance control and constant current control. The inputs to the charge balance compensator are the actual SOC value and the reference SOC value for each battery. ref The difference. SOC ref The average SOC of each battery is calculated as shown in formula (1), where the parameter is... For battery access signal, when A value of 1 indicates that the battery is connected to the system (not short-circuited) and is not in a constant voltage charging state; otherwise... A value of 0 indicates that the battery is not connected to the system or is in a constant voltage charging state.

[0062]

[0063] Figure 7 En is the charge balance enable signal. When En is 1, the charge balance function is activated, and the output of the charge balance compensator is multiplied by the constant current charging reference value I. ref (For example, 1C current, determined according to the battery manual), to obtain the actual expected value I of the battery charging current. chg1 ,I chg2 ,…,I cghN Actual expected values ​​and measured battery charging current values ​​I1, I2, ..., I N The difference is used as the input of the current compensator, and the output of the compensator is the control signal duty cycle D1, D2, ..., D of the battery-side power converter. N According to the box Figure 7 When the battery is under constant current charging (including the charge balancing module), the final output control signals are D1, D2, ..., D. N It can be given by formula (2).

[0064]

[0065] Figure 8 This is a control block diagram for the battery system in a constant voltage charging state, ultimately outputting control signals D1, D2, ..., D. N It can be given by formula (3). It should be noted that... Figure 7 and Figure 8 Constant current charging and constant voltage charging are described separately. If a battery in the battery system is the first to switch from constant current charging to constant voltage charging mode, it will not affect the normal charging of other batteries, because each battery can switch charging modes independently.

[0066]

[0067] In formula (3), V1, V2, ..., V N This represents the actual voltage value, V. ref This indicates the voltage reference value.

[0068] Specifically, the control method when the battery system is in constant voltage charging state is as follows: when the battery module is in constant voltage charging state, the voltage reference value and the actual voltage value of the battery module are obtained respectively; the duty cycle of the power converter for constant voltage charging of the battery module is obtained according to the voltage reference value and the actual voltage value.

[0069] More specifically, the duty cycle of the power converter during constant-voltage charging of the battery module, based on the voltage reference value and the actual voltage value, can be obtained using the following scheme: Calculate the difference between the voltage reference value and the actual voltage value, and control the difference using a preset third control method (e.g., inputting it into a voltage compensator) to obtain the duty cycle of the power converter during constant-voltage charging of the battery module. For example, the third control method includes, but is not limited to: PI (proportional integral controller) control and predictive control.

[0070] Figure 9 A schematic diagram of the control flow during battery system charging. (Example) Figure 9 As shown, for any battery module in the battery system, the voltage of the battery module is first obtained, and it is determined whether the voltage has reached a preset first threshold (e.g., 4.2V). When the voltage has not reached the first threshold, it is determined that the battery module is in constant current charging mode. When the voltage reaches the first threshold, it is determined that the battery module is in constant voltage charging mode.

[0071] When the battery module enters constant voltage charging mode, it can be charged using existing technologies, such as according to... Figure 8 The battery system is charged in a manner where the battery voltage remains constant while the charging current gradually decreases. When the charging current of the battery module is less than a preset second threshold (e.g., 1 / 20C), it indicates that the constant voltage charging mode of the battery module has ended.

[0072] When the battery module enters constant current charging mode, it checks whether the charge balance enable signal of the battery module meets preset conditions. If the preset conditions are met, it indicates that the battery module is healthy and can proceed as planned. Figure 7 The method used to achieve charge balance during constant current charging is as follows: En = 1, and the charging current I is configured. chg1 If the preset conditions are not met, it indicates that the battery module is unhealthy and cannot be used according to the instructions. Figure 7 This method performs charge balancing during constant current charging. Unhealthy batteries can be removed from the system by turning off the battery-side switch, or they can be charged individually. The charging current for this battery is determined based on its health status (generally a small current is used to ensure safety). Because it is not included in the SOC balancing algorithm, its charging current differs from other charge-balanced batteries, i.e., En = 0, and the charging current I is configured. chg2 During constant current charging, the voltage across the battery module increases. When the voltage reaches the first threshold, the battery module is determined to have entered constant voltage charging mode.

[0073] Therefore, the battery system charging control method provided in Embodiment 1 of the present invention can achieve the following objectives:

[0074] (1) Implement decoupling control of multiple output paths to reduce mutual interference between different paths;

[0075] (2) To achieve independent constant current charging and constant voltage charging of batteries with different output paths;

[0076] (3) Achieve charge balance control among the batteries;

[0077] (4) Enable the switching between the constant current charging mode, constant voltage charging mode and charge balance charging mode of the battery system.

[0078] Example 2

[0079] Corresponding to Embodiment 1 of the present invention, Embodiment 2 of the present invention provides a battery system charging control device. The battery system includes multiple battery modules, which are connected to a power source via a power converter. Specifically, as shown... Figure 10 As shown, the battery system charging control device includes a first acquisition module 20, a second acquisition module 21, a compensation module 22, and an adjustment module 23.

[0080] Specifically, for any battery module, when the battery module is in a constant current charging state, the first acquisition module 20 is used to acquire the charge balance enable signal of the battery module.

[0081] When the charge balance enable signal meets the preset conditions, the second acquisition module 21 is used to acquire the charge compensation value corresponding to the battery module.

[0082] The compensation module 22 is used to obtain the expected value of the charging current of the battery module based on the charge compensation value.

[0083] The adjustment module 23 is used to obtain the duty cycle of the power converter when it is charging the battery module at a constant current, based on the expected value of the charging current.

[0084] For specific details regarding the charging control of the aforementioned battery system, please refer to the relevant documentation. Figures 1 to 9 The relevant descriptions and effects in the illustrated embodiments are for understanding purposes only and will not be repeated here.

[0085] Example 3

[0086] This invention also provides a battery system, which includes a power supply side circuit module, a battery side circuit module, and a controller module. A single-input power converter of the power supply side circuit module is coupled to multiple output battery paths of the battery side circuit module. The control module is communicatively connected to the switch of the single-input power converter and the switches of the multiple output batteries.

[0087] Figure 3 Here is a circuit example of a single-input multiple-output battery system, such as Figure 3 As shown, the battery system includes: an input port, where a single-input power converter on the power supply side is coupled to multiple output battery paths; an output port, where multiple paths are coupled to one end of an inductor to provide power / energy to multiple batteries via the output port, including back-to-back switches for bidirectional battery energy transfer; and a control circuit connected to the power converter switch on the input power supply side and the battery switch on the output side.

[0088] The controller module includes a processor and a memory, which can be connected via a bus or other means.

[0089] The processor can be a central processing unit (CPU). The processor can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations of the above types of chips.

[0090] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the battery system charging control method in this embodiment of the invention (e.g., Figure 10 The first acquisition module 20, the second acquisition module 21, the compensation module 22, and the adjustment module 23 are shown. The processor executes various functional applications and data processing by running non-transitory software programs, instructions, and modules stored in the memory, thereby implementing the battery system charging control method in the above method embodiments.

[0091] The memory may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created by the processor, etc. Furthermore, the memory may include high-speed random access memory and non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory may optionally include memory remotely located relative to the processor, which can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0092] The one or more modules are stored in the memory, and when executed by the processor, they perform actions such as... Figures 1 to 9 The battery system charging control method in the illustrated embodiment.

[0093] For specific details regarding the aforementioned battery system, please refer to the relevant documentation. Figures 1 to 10 The relevant descriptions and effects in the illustrated embodiments are for understanding purposes only and will not be repeated here.

[0094] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium can also include combinations of the above types of memory.

[0095] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery system charging control method, characterized in that, The battery system includes multiple battery modules, which are connected to a power source via a power converter. Only one battery module is connected to the power converter at any given time. The battery system charging control method includes: For any battery module, when the battery module is in a constant current charging state, the charge balance enable signal of the battery module is acquired. When the charge balance enable signal meets the preset conditions, the actual charge value and the charge reference value of the battery module are obtained respectively; and the charge compensation value corresponding to the battery module is obtained based on the actual charge value and the charge reference value. Before obtaining the charge reference value of the battery module, the process also includes: Determine the charging mode of each battery module in the battery system whose charge balance enable signal meets the preset conditions; Obtain the actual charge value of each battery module in the battery system that meets the preset condition and is in constant current charging mode; Calculate the average value of the actual charge of all battery modules in the battery system whose charge balance enable signal meets the preset condition and are in constant current charging mode, and use the average value as the charge reference value. The expected charging current of the battery module is obtained based on the charge compensation value; the process of obtaining the expected charging current of the battery module based on the charge compensation value includes: Obtain the constant current charging reference value of the battery module; The expected charging current of the battery module is obtained by multiplying the charge compensation value by the constant current charging reference value. The duty cycle of the power converter when it charges the battery module at a constant current is obtained from the expected value of the charging current. After obtaining the duty cycle of the power converter when charging the battery module at a constant current based on the expected value of the charging current, the method further includes: adjusting the last one or the last few duty cycles to 0; The state of the battery module switch is obtained; the state of the battery module switch is used to determine whether the power converter is connected to the battery module; when the power converter is connected to the battery module, the constant current charging of the battery module is controlled by the duty cycle.

2. The method according to claim 1, characterized in that, The duty cycle of the power converter when charging the battery module at a constant current, based on the expected charging current value, includes: Obtain the charging current measurement value of the battery module; The duty cycle of the power converter when it is charging the battery module at a constant current is obtained based on the expected value of the charging current and the measured value of the charging current.

3. The method according to claim 1, characterized in that, Before acquiring the charge balance enable signal of the battery module, the process also includes: Obtain the voltage of the battery module; Determine whether the voltage has reached a preset first threshold; When the voltage does not reach the first threshold, it is determined that the battery module is in constant current charging mode; When the voltage reaches the first threshold, the battery module is determined to be in constant voltage charging mode.

4. The method according to claim 1, characterized in that, Also includes: When the battery module is in a constant voltage charging state, the voltage reference value and the actual voltage value of the battery module are obtained respectively. The duty cycle of the power converter when it is charging the battery module at a constant voltage is obtained based on the voltage reference value and the actual voltage value.

5. A battery system charging control device, characterized in that, The battery system includes multiple battery modules, which are connected to a power source via a power converter. Only one battery module is connected to the power converter at any given time. The battery charging control device includes a first acquisition module, a second acquisition module, a compensation module, and an adjustment module. For any battery module, when the battery module is in a constant current charging state, the first acquisition module is used to acquire the charge balance enable signal of the battery module. When the charge balance enable signal meets the preset conditions, the second acquisition module is used to acquire the actual charge value and the charge reference value of the battery module respectively. Based on the actual charge value and the charge reference value, a charge compensation value corresponding to the battery module is obtained; Before obtaining the charge reference value of the battery module, the process also includes: Determine the charging mode of each battery module in the battery system whose charge balance enable signal meets the preset conditions; Obtain the actual charge value of each battery module in the battery system that meets the preset condition and is in constant current charging mode; Calculate the average value of the actual charge of all battery modules in the battery system whose charge balance enable signal meets the preset condition and are in constant current charging mode, and use the average value as the charge reference value. The compensation module is used to obtain the expected value of the charging current of the battery module based on the charge compensation value; the compensation module includes: Obtain the constant current charging reference value of the battery module; The expected charging current of the battery module is obtained by multiplying the charge compensation value by the constant current charging reference value. The adjustment module is used to obtain the duty cycle of the power converter when it is charging the battery module at a constant current, based on the expected value of the charging current. After obtaining the duty cycle of the power converter when charging the battery module at a constant current based on the expected value of the charging current, the method further includes: adjusting the last one or the last few duty cycles to 0; The state of the battery module switch is obtained; the state of the battery module switch is used to determine whether the power converter is connected to the battery module; when the power converter is connected to the battery module, the constant current charging of the battery module is controlled by the duty cycle.

6. A battery system, characterized in that, include: The system comprises a power supply side circuit module, a battery side circuit module, and a control module. A single-input power converter of the power supply side circuit module is coupled to multiple output battery paths of the battery side circuit module. The control module is communicatively connected to the switches of the single-input power converter and the multiple output batteries. The control module includes a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes these computer instructions to perform the battery system charging control method according to any one of claims 1-4.

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