Battery system control method, energy storage device and battery system

Abstract

This application discloses a battery system control method, energy storage device, and battery system. The method comprises: obtaining parameter information of each battery pack in the battery system, including battery capacity and state of charge; when a discharge command is detected, determining a target battery pack to be discharged based on the battery system's discharge power and the battery capacity and state of charge of each battery pack in the battery system; and controlling the target battery pack to discharge. By jointly determining an appropriate target battery pack for discharge based on the battery system's discharge power, battery capacity, and state of charge, the likelihood of overcurrent and cross-charging can be reduced to a certain extent, effectively preventing abnormal battery pack conditions such as frequent overcurrent and cross-charging.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a control method for a battery system, an energy storage device, and a battery system. Background Art

[0002] To improve the battery life of energy storage devices, multiple battery packs are typically connected in parallel. However, simply controlling the simultaneous discharge of multiple battery packs can easily lead to problems such as overcurrent and cross-charging, affecting the normal operation of the battery packs.

[0003] Therefore, in a scenario where multiple battery packs are connected in parallel, how to control the discharge of the battery packs to avoid abnormalities in the battery packs becomes an urgent problem that needs to be solved. Summary of the Invention

[0004] The present application provides a control method, energy storage device and battery system for a battery system. By jointly determining a suitable target battery pack for discharge based on the discharge power, battery capacity and state of charge of the battery system, the possibility of overcurrent and mutual charging can be reduced to a certain extent, and abnormal conditions such as frequent overcurrent and mutual charging of the battery pack can be effectively avoided.

[0005] In a first aspect, the present application provides a control method for a battery system, which is applied to a master control battery pack in the battery system, wherein the battery system includes at least two battery packs. The method includes:

[0006] Acquire parameter information of each battery pack in the battery system, wherein the parameter information includes battery capacity and state of charge; when a discharge instruction is detected, determine a target battery pack to be discharged based on the discharge power of the battery system and the battery capacity and state of charge of each battery pack in the battery system; and control the target battery pack to discharge.

[0007] In a second aspect, the present application further provides an energy storage device, the energy storage device comprising a battery pack, a memory, and a processor;

[0008] The memory is used to store computer programs;

[0009] The processor is configured to implement the above-mentioned battery system control method when executing the computer program.

[0010] In a third aspect, the present application further provides a battery system, comprising at least two battery packs and a processor;

[0011] The processor is used to implement the above-mentioned control method of the battery system.

[0012] The present application discloses a control method for a battery system, an energy storage device, and a battery system. By acquiring parameter information of each battery pack in the battery system, the battery capacity and state of charge of each battery pack can be obtained. When a discharge instruction is detected, the target battery pack to be discharged is determined based on the discharge power of the battery system and the battery capacity and state of charge of each battery pack in the battery system, and the target battery pack is controlled to discharge. It is possible to jointly determine a suitable target battery pack for discharge based on the discharge power, battery capacity, and state of charge of the battery system, thereby reducing the possibility of overcurrent and mutual charging to a certain extent, and effectively avoiding abnormal conditions such as frequent overcurrent and mutual charging in the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0014] Figure 1 is a schematic diagram of a battery system provided in an embodiment of the present application;

[0015] Figure 2 This is a schematic structural diagram of an energy storage device provided in an embodiment of the present application;

[0016] Figure 3 is a schematic flow chart of a control method for a battery system provided in an embodiment of the present application;

[0017] Figure 4 is a schematic diagram of a battery pack provided in an embodiment of the present application;

[0018] Figure 5 is a schematic flowchart of sub-steps for determining a target battery pack provided in an embodiment of the present application;

[0019] Figure 6 is a schematic flow chart of sub-steps of another battery system control method provided in an embodiment of the present application;

[0020] Figure 7 is a schematic flow chart of sub-steps of another battery system control method provided in an embodiment of the present application;

[0021] Figure 8 is a schematic flow chart of sub-steps of another battery system control method provided in an embodiment of the present application;

[0022] Figure 9 is a schematic diagram of charging a battery pack provided in an embodiment of the present application;

[0023] Figure 10 It is a schematic flowchart of the sub-steps of another battery system control method provided in an embodiment of the present application. DETAILED DESCRIPTION

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

[0025] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, combined, or partially merged, so the actual execution order may vary depending on the actual situation.

[0026] It should be understood that the terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0027] It will also be understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0028] The embodiments of the present application provide a battery system control method, energy storage device, and battery system. The battery system control method can be applied to a master battery pack in a battery system. By determining a suitable target battery pack for discharge based on the battery system's discharge power, battery capacity, and state of charge, the possibility of overcurrent and cross-charging can be reduced to a certain extent, effectively avoiding frequent abnormal conditions such as overcurrent and cross-charging in the battery pack.

[0029] See also Figure 1 , Figure 1 Schematic diagram of a battery system provided in an embodiment of the present application. Figure 1 As shown, the battery system includes at least two parallel battery packs, at least two of which include a master battery pack; each battery pack includes a cell and a switch tube for controlling charging and discharging. The switch tube can be a field effect tube (Metal-Oxide-SemiconductorField-Effect Transistor, MOS tube), a transistor or other types of switch tubes, such as Figure 1 The discharge MOS tube and the charging MOS tube shown in the figure. The battery system may also include a load resistor R1, a battery port capacitor C1, and an inverter. The load resistor R1 and the battery port capacitor C1 are connected to the positive and negative lines, and the inverter can be connected to an external power supply device or power consumption device. For example, during the charging process, the inverter can be connected to a PV (Photo Voltaic, photovoltaic) panel.

[0030] For example, the battery packs in a battery system can be installed in one or more energy storage devices. The energy storage device can be a mobile energy storage device, a home energy storage device, or a vehicle-mounted energy storage device. The energy storage device can include at least one battery pack. For example, a master battery pack or a slave battery pack can be installed in the energy storage device. Another example is that a master battery pack and at least one slave battery pack can be installed in the energy storage device. Each battery pack has multiple cells connected in series.

[0031] In the embodiment of the present application, the battery pack in the battery system can be controlled to charge and discharge. For example, a photovoltaic charging power source (such as Figure 1 The battery pack can be charged by power supply equipment such as PV panels in the battery system, AC charging power supply, etc. For another example, the battery pack in the battery system can be discharged to external power-consuming devices.

[0032] In some embodiments, when discharging battery packs in a battery system, the master battery pack can obtain parameter information of each battery pack in the battery system, which may include battery capacity and state of charge. Upon detecting a discharge instruction, the master battery pack determines the target battery pack to be discharged based on the discharge power of the battery system and the battery capacity and state of charge of each battery pack in the battery system, and controls the target battery pack to discharge.

[0033] It should be noted that in the control method of the battery system provided in the present application, the master battery pack does not simply control all the battery packs in the battery system to discharge, but selects a suitable target battery pack for discharge based on the discharge power of the battery system and the battery capacity and charge state of each battery pack in the battery system.

[0034] It is understandable that when the discharge power is high, if a battery pack with a smaller battery capacity is selected for discharge, the battery pack may easily trigger overcurrent protection. Furthermore, if battery packs with significantly different states of charge are selected for discharge, the battery packs may easily charge each other. Therefore, in the method provided in this application, selecting an appropriate target battery pack for discharge based on the discharge power of the battery system and the battery capacity and state of charge of each battery pack in the battery system can, to a certain extent, reduce the possibility of overcurrent and cross-charging, avoid frequent abnormal conditions such as overcurrent and cross-charging, and improve the user experience.

[0035] See also Figure 2 , Figure 2 1 is a schematic diagram of the structure of an energy storage device 1000 provided in an embodiment of the present application. The energy storage device 1000 may include a processor 1001, a memory 1002, and a battery pack 1003, wherein the processor 1001, the memory 1002, and the battery pack 1003 may be connected via a bus, such as an I2C (Inter-integrated Circuit) bus or any other suitable bus.

[0036] The memory 1002 may include a storage medium and an internal memory. The storage medium may store an operating system and a computer program. The computer program includes program instructions that, when executed, enable the processor to execute any of the battery system control methods.

[0037] Among them, the processor 1001 is used to provide computing and control capabilities to support the operation of the entire energy storage device 1000.

[0038] The processor 1001 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0039] In one embodiment, the processor 1001 is configured to run a computer program stored in the memory 1002 to implement the following steps:

[0040] Acquire parameter information of each battery pack in the battery system, wherein the parameter information includes battery capacity and state of charge; when a discharge instruction is detected, determine a target battery pack to be discharged based on the discharge power of the battery system and the battery capacity and state of charge of each battery pack in the battery system; and control the target battery pack to discharge.

[0041] In one embodiment, when determining the target battery pack to be discharged based on the discharge power of the battery system and the battery capacity and state of charge of each battery pack in the battery system, the processor 1001 is configured to implement:

[0042] If the battery capacities of the battery packs in the battery system are different, and the discharge power of the battery system is greater than or equal to a first discharge power threshold, the battery pack with the largest battery capacity is determined as the target battery pack; if the battery capacities of the battery packs in the battery system are different, and the discharge power is less than the first discharge power threshold, the battery pack with the largest state of charge is determined as the target battery pack.

[0043] In one embodiment, after determining the battery pack with the largest battery capacity as the target battery pack and controlling the target battery pack to discharge, the processor 1001 is configured to implement:

[0044] When it is detected that the discharge power of the battery system is less than a second discharge power threshold, the battery pack with the largest state of charge is controlled to discharge, and the second discharge power threshold is less than the first discharge power threshold.

[0045] In one embodiment, when determining the target battery pack to be discharged based on the discharge power of the battery system and the battery capacity and state of charge of each battery pack in the battery system, the processor 1001 is configured to implement:

[0046] If the battery capacities of the battery packs in the battery system are the same but the states of charge are different, the battery pack with the largest state of charge is determined as the target battery pack; if the battery capacities and states of charge of the battery packs in the battery system are the same, all the battery packs in the battery system are determined as the target battery packs.

[0047] In one embodiment, after determining all battery packs in the battery system as the target battery pack, the processor 1001 is configured to control the target battery pack to discharge:

[0048] If the discharge power is less than a first discharge power threshold, all battery packs in the battery system are controlled to discharge.

[0049] In one embodiment, the processor 100 is further configured to implement:

[0050] When a charging instruction is detected, a battery pack with the smallest state of charge in the battery system is determined as a rechargeable battery pack; and the rechargeable battery pack is charged.

[0051] In one embodiment, the processor 1001, when charging the rechargeable battery pack, is configured to implement:

[0052] Determine a total power requirement of the rechargeable battery pack, where the total power requirement is the sum of the power requirements of each rechargeable battery pack; when the total power requirement is greater than the maximum output power of the power supply device connected to the battery system, charge the rechargeable battery pack based on the maximum output power.

[0053] In addition, in some other possible battery systems, the battery system may include a power conversion device and at least two battery packs, wherein the power conversion device is connected to the at least two battery packs respectively. The power conversion device is provided with a processor, and the processor can implement the control method provided in the embodiments of the present application to control the battery packs in the battery system.

[0054] It should be understood that the above is only a schematic example of the battery system in the embodiment of the present application. In actual application scenarios, the battery system that implements the control method provided by the present application may be composed of more or fewer devices, or some of the devices may be replaced, and the present application does not limit this.

[0055] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0056] like Figure 3 As shown, the control method of the battery system includes steps S101 to S103.

[0057] Step S101: Acquire parameter information of each battery pack in the battery system, wherein the parameter information includes battery capacity and state of charge.

[0058] For example, the parameter information of each battery pack in the battery system can be read. For example, the parameter information of each battery pack in the battery system can be read through a battery management system (BMS).

[0059] The parameter information may include battery capacity and state of charge (SOC). It is understood that the battery capacity refers to the capacity of the battery pack when it is fully charged, and the SOC refers to the percentage of the remaining capacity of the battery pack to the battery capacity.

[0060] See also Figure 4 , Figure 4 is a schematic diagram of a battery pack provided in an embodiment of the present application. In a possible scenario, Figure 4As shown, the battery system may include battery pack 1, battery pack 2, and battery pack 3. Battery pack 1 has a battery capacity of 5 kWh and a state of charge of 30%; battery pack 2 has a battery capacity of 2 kWh and a state of charge of 70%; and battery pack 3 has a battery capacity of 2 kWh and a state of charge of 50%.

[0061] For example, the open circuit voltage method or the ampere-hour integration method can be used to calculate the state of charge of a battery pack. It should be noted that the open circuit voltage method uses the relatively fixed functional relationship between the open circuit voltage and the state of charge when the battery pack is stationary for a long time, so the state of charge can be estimated based on the open circuit voltage. The ampere-hour integration method calculates the percentage of change in charge (i.e., the changed state of charge) by calculating the integral of the charge and discharge current over a certain period of time and the corresponding time, and ultimately calculates the difference between the initial state of charge and the changed state of charge, i.e., the current state of charge.

[0062] In the above embodiment, the battery capacity and state of charge of each battery pack can be obtained by acquiring the parameter information of each battery pack in the battery system.

[0063] Step S102 : When a discharge instruction is detected, a target battery pack to be discharged is determined based on the discharge power of the battery system and the battery capacity and state of charge of each battery pack in the battery system.

[0064] It should be noted that in the embodiment of the present application, when it is detected that an external power-consuming device is connected to the energy storage device, a discharge instruction can be generated, and the battery pack in the battery system can be controlled to discharge according to the discharge instruction.

[0065] In some embodiments, when a discharge instruction is detected, a target battery pack to be discharged is determined based on the discharge power of the battery system and the battery capacity and state of charge of each battery pack in the battery system.

[0066] It should be noted that the discharge power of a battery system refers to the power output of the battery system, which is determined by the power required by the load. For example, a load connected to the battery system can send its power requirements to the master battery pack. The master battery pack can then sum the power requirements of each load to obtain the battery system's discharge power.

[0067] The discharge power of a battery system can be added together. In a battery system, since the battery packs are connected in parallel, for example, when multiple battery packs are discharging simultaneously, the discharge power of the battery system is the sum of the discharge powers of each battery pack.

[0068] It can be understood that the discharge power and discharge current of each battery pack are positively correlated. In order to ensure the safety of the battery pack, an overcurrent protection threshold is set for each battery pack. When the discharge current of the battery pack is greater than the overcurrent protection threshold, the overcurrent protection will be triggered. The overcurrent protection threshold can be set according to the battery capacity. For example, generally speaking, the overcurrent protection threshold corresponding to the battery pack with a large battery capacity is larger, and the overcurrent protection threshold corresponding to the battery pack with a small battery capacity is smaller. Therefore, when the discharge power of the battery system is large, priority is given to controlling the discharge of the battery pack with a large battery capacity, thereby effectively reducing the possibility of the battery pack with a small battery capacity triggering the overcurrent protection. When the discharge power of the battery system is small, in order to ensure the efficiency of the discharge, it can be effectively considered to control the discharge of the battery pack with a larger state of charge.

[0069] In the above embodiment, by determining the target battery pack to be discharged based on the discharge power of the battery system and the battery capacity and state of charge of each battery pack in the battery system, it is possible to jointly determine the appropriate target battery pack based on the discharge power, battery capacity and state of charge of the battery system.

[0070] Step S103: Control the target battery pack to discharge.

[0071] In the embodiment of the present application, after the target battery pack to be discharged is determined, the target battery pack may be controlled to discharge.

[0072] For example, a control instruction may be sent to the discharge switch tube corresponding to the target battery pack, and the discharge switch tube switches on the connection between the target battery pack and the external electrical device according to the control instruction, so that the target battery pack discharges the external electrical device.

[0073] Exemplarily, the switch transistor may be a MOS transistor. For example, if the target battery pack is battery pack 1, a control instruction may be sent to the discharge MOS transistor corresponding to battery pack 1, and the discharge MOS transistor may connect battery pack 1 to the external power device according to the control instruction.

[0074] It should be noted that when the discharge MOS transistor is turned on, the charging MOS transistor connected in series with the discharge MOS transistor is not turned on. Therefore, current can flow through the body diode of the charging MOS transistor. When the current is large, for example, when the current is greater than a preset current threshold, the charging MOS transistor can be controlled to be turned on to avoid damaging the charging MOS transistor. The preset current threshold can be set based on the operating parameters of the body diode, and the specific value is not limited here.

[0075] In the above embodiment, by controlling the target battery pack to discharge, rather than simply controlling all battery packs in the battery system to discharge, the possibility of overcurrent and cross-charging can be reduced to a certain extent, effectively avoiding abnormal conditions such as frequent overcurrent and cross-charging of the battery packs.

[0076] In the embodiments of the present application, how to determine the target battery pack to be discharged will be described in detail.

[0077] See also Figure 5 , Figure 5 This is a schematic flowchart of sub-steps for determining a target battery pack provided by an embodiment of the present application. In step S102, determining the target battery pack to be discharged may include the following steps S201 to S204.

[0078] Step S201: If the battery capacities of the battery packs in the battery system are different and the discharge power of the battery system is greater than or equal to a first discharge power threshold, the battery pack with the largest battery capacity is determined as the target battery pack.

[0079] It should be noted that in the embodiments of the present application, the target battery pack to be discharged can be determined based on the discharge power of the battery system, the battery capacity of each battery pack, and the state of charge. For example, it can be determined whether the discharge power of the battery system is greater than a first discharge power threshold, whether the battery capacity of each battery pack is the same, whether the state of charge of each battery pack is the same, etc.

[0080] Exemplarily, when the battery capacities of the battery packs in the battery system are different and the discharge power of the battery system is greater than or equal to a first discharge power threshold, the battery pack with the largest battery capacity is determined as the target battery pack.

[0081] For example, Figure 4 As shown, the battery capacity of battery pack 1 is 5kWh, the battery capacity of battery pack 2 is 2kWh, and the battery capacity of battery pack 3 is 2kWh. Among them, battery pack 1 is the battery pack with the largest battery capacity in the battery system, and battery pack 1 can be determined as the target battery pack.

[0082] It should be noted that the first discharge power threshold can be set based on the discharge power of the battery pack with the smallest battery capacity, and the specific value is not limited here. It is understandable that the overcurrent protection threshold corresponding to the battery pack with a large battery capacity is larger, and the overcurrent protection threshold corresponding to the battery pack with a small battery capacity is smaller; when the discharge power of the battery system is greater than or equal to the first discharge power threshold, a large inrush current will be generated at the moment the load is connected. This inrush current may exceed the overcurrent protection threshold corresponding to the battery pack with a small battery capacity, causing the battery pack to trigger overcurrent protection and stop discharging. Therefore, when the discharge power of the battery system is greater than or equal to the first discharge power threshold, the battery pack with the largest battery capacity is preferentially used for discharge, which can reduce the possibility of the battery pack triggering overcurrent protection.

[0083] In the above embodiment, when the battery capacities of the battery packs in the battery system are different and the discharge power of the battery system is greater than or equal to the first discharge power threshold, the battery pack with the largest battery capacity is determined as the target battery pack. Since the battery pack with a large battery capacity can withstand a larger impact current, the possibility of the battery pack triggering overcurrent protection can be reduced.

[0084] Step S202: If the battery capacities of the battery packs in the battery system are different and the discharge power is less than the first discharge power threshold, the battery pack with the largest state of charge is determined as the target battery pack.

[0085] Exemplarily, when the battery capacities of the battery packs in the battery system are different and the discharge power of the battery system is less than a first discharge power threshold, the battery pack with the largest state of charge is determined as the target battery pack.

[0086] For example, Figure 5 As shown, the state of charge of battery pack 1 is 30%, the state of charge of battery pack 2 is 70%, and the state of charge of battery pack 3 is 50%. Among them, battery pack 2 has the largest state of charge in the battery system and can be determined as the target battery pack.

[0087] It should be noted that when the battery system's discharge power is less than the first discharge power threshold, the battery pack will not trigger overcurrent protection. However, to ensure the battery system's discharge efficiency, it is necessary to use the battery pack with the highest state of charge for discharge. Furthermore, in this situation, using the battery pack with the highest state of charge for discharge can make the state of charge of each battery pack more consistent, making it easier for the battery packs to be connected in parallel to provide greater discharge power.

[0088] In the above embodiment, when the battery capacities of the battery packs in the battery system are different and the discharge power is less than the first discharge power threshold, the battery pack with the largest state of charge is determined as the target battery pack, thereby ensuring the discharge efficiency of the battery system.

[0089] Step S203: If the battery capacities of the battery packs in the battery system are the same but the states of charge are different, the battery pack with the largest state of charge is determined as the target battery pack.

[0090] It should be noted that when the battery capacities of the battery packs in the battery system are the same, the ability of the battery packs to withstand the inrush current is the same. Therefore, there is no need to consider the relationship between the discharge power of the battery system and the first discharge power threshold.

[0091] Exemplarily, when the battery capacities of the battery packs in the battery system are the same but the states of charge are different, the battery pack with the largest state of charge is determined as the target battery pack.

[0092] In the above embodiment, when the battery capacities of the battery packs in the battery system are the same but the states of charge are different, the battery pack with the largest state of charge is determined as the target battery pack. This can avoid selecting multiple batteries with large differences in state of charge to discharge together, which may easily cause the battery packs to charge each other.

[0093] Step S204 : If the battery capacities and states of charge of the battery packs in the battery system are the same, all the battery packs in the battery system are determined as the target battery packs.

[0094] Exemplarily, when the battery capacities and states of charge of the battery packs in the battery system are the same, all the battery packs in the battery system are determined as target battery packs.

[0095] It should be noted that since the state of charge of each battery pack is the same, there is no possibility of mutual charging between different battery packs.

[0096] In the above embodiment, when the battery capacities and states of charge of the battery packs in the battery system are the same, all the battery packs in the battery system are determined as target battery packs, thereby effectively improving the discharge efficiency of the battery system.

[0097] In the embodiment of the present application, after the target battery pack to be discharged is determined, the target battery pack may be controlled to discharge.

[0098] See also Figure 6 , Figure 6 It is a schematic flowchart of the sub-steps of another battery system control method provided in an embodiment of the present application, which may include the following steps S301 to S304.

[0099] Step S301: Acquire parameter information of each battery pack in the battery system, wherein the parameter information includes battery capacity and state of charge.

[0100] It can be understood that the above step S301 is the same as step S101 and will not be repeated here.

[0101] Step S302: When a discharge instruction is detected, if the battery capacities of the battery packs in the battery system are different and the discharge power of the battery system is greater than or equal to a first discharge power threshold, the battery pack with the largest battery capacity is determined as the target battery pack.

[0102] It can be understood that the above step S302 is the same as step S201 and will not be repeated here.

[0103] Step S303: Control the target battery pack to discharge.

[0104] It can be understood that the above step S303 is the same as step S103 and will not be repeated here.

[0105] Step S304: When it is detected that the discharge power of the battery system is less than a second discharge power threshold, the battery pack with the largest state of charge is controlled to discharge, and the second discharge power threshold is less than the first discharge power threshold.

[0106] For example, when it is detected that the battery system's discharge power is less than a second discharge power threshold, the battery pack with the highest state of charge is controlled to discharge. The second discharge power threshold is less than the first discharge power threshold. The second discharge power threshold can be set based on actual conditions, and the specific value is not limited here.

[0107] For example, the first discharge power threshold may be 3000W, and the second discharge power threshold may be 1400W; when the discharge power of the battery system is greater than or equal to 3000W, the battery pack with the largest battery capacity is controlled to discharge; when the discharge power of the battery system is less than 1400W, the battery pack with the largest state of charge is controlled to discharge.

[0108] It should be noted that in the process of controlling the battery pack with the largest battery capacity to discharge, the discharge power of the battery system may change with the change of the load. For example, the discharge function of the battery system may increase or decrease. Among them, when the discharge power of the battery system is less than the first discharge power threshold, you can choose to switch to the battery pack with the highest state of charge for discharge. However, in order to avoid frequent switching of the discharged battery pack near the first discharge power threshold due to discharge power jitter, a second discharge power threshold can be set, and the second discharge power threshold is less than the first discharge power threshold. When the discharge power of the battery system is less than the second discharge power threshold, the battery pack with the largest state of charge is controlled to discharge to improve the discharge efficiency. Subsequently, when the discharge power is greater than or equal to the first discharge power threshold, you can switch to the battery pack with the largest battery capacity again for discharge to avoid overcurrent.

[0109] For example, assume the first discharge power threshold is 3000W and the second discharge power threshold is 1400W. When the battery system discharge power is less than 1400W, to ensure the battery system's discharge efficiency and prevent a single battery pack from running out of power, discharge can automatically switch to the battery pack with the highest state of charge. Subsequently, when the battery system discharge power is greater than or equal to 3000W, discharge switches to the battery pack with the largest battery capacity.

[0110] In the above embodiment, after controlling the battery pack with the largest battery capacity to discharge, when it is detected that the discharge power of the battery system is less than the second discharge power threshold, the battery pack with the largest state of charge is controlled to discharge, thereby outputting a larger discharge power, ensuring the discharge efficiency of the battery system and avoiding the exhaustion of power in a single battery pack.

[0111] See also Figure 7 , Figure 7 It is a schematic flowchart of the sub-steps of another battery system control method provided in an embodiment of the present application, which may include the following steps S401 to S403.

[0112] Step S401: Acquire parameter information of each battery pack in the battery system, wherein the parameter information includes battery capacity and state of charge.

[0113] It can be understood that the above step S301 is the same as step S101 and will not be repeated here.

[0114] Step S402: When a discharge instruction is detected, if the battery capacities and state of charge of the battery packs in the battery system are the same, all the battery packs in the battery system are determined as the target battery packs.

[0115] It can be understood that the above step S402 is the same as step S204 and will not be repeated here.

[0116] Step S403: If the discharge power is less than a first discharge power threshold, all battery packs in the battery system are controlled to discharge.

[0117] For example, the current discharge power of the discharge system may be detected, and when the discharge power is less than a first discharge power threshold, all battery packs in the battery system are controlled to discharge.

[0118] It should be noted that when the battery packs in a battery system have the same battery capacity and the corresponding overcurrent protection thresholds are the same, during discharge, if the battery system's discharge power is greater than or equal to a first discharge power threshold, the instantaneous inrush current generated by the load connection may exceed the corresponding overcurrent protection thresholds of each battery pack, causing each battery pack to trigger overcurrent protection and cease discharge. Therefore, to ensure normal discharge, it is necessary to control all battery packs in the battery system to discharge only when the discharge power is less than the first discharge power threshold.

[0119] In the above embodiment, by controlling all battery packs in the battery system to discharge when the discharge power is less than the first discharge power threshold, the possibility of the battery pack triggering the overcurrent protection can be reduced.

[0120] It should be noted that, in the embodiment of the present application, in addition to controlling the battery pack to discharge, the battery pack can also be controlled to charge. The following will describe in detail how to control the battery pack to charge.

[0121] See also Figure 8 , Figure 8It is a schematic flowchart of the sub-steps of another battery system control method provided in an embodiment of the present application, which may include the following steps S501 to S503.

[0122] Step S501: Acquire parameter information of each battery pack in the battery system, wherein the parameter information includes battery capacity and state of charge.

[0123] It can be understood that the above step S501 is the same as step S101 and will not be repeated here.

[0124] Step S502: When a charging instruction is detected, the battery pack with the smallest state of charge in the battery system is determined as a charging battery pack.

[0125] In some embodiments, when a charging instruction is detected, a battery pack with the smallest state of charge in the battery system is determined to be a charging battery pack.

[0126] In an embodiment of the present application, when it is detected that a power supply device is connected to an energy storage device, a charging instruction can be generated, the battery pack with the smallest state of charge in the battery system can be determined as the charging battery pack, and the charging battery pack in the battery system can be controlled to charge according to the charging instruction.

[0127] See also Figure 9 , Figure 9 This is a schematic diagram of a battery pack charging method provided by an embodiment of the present application. Figure 9 As shown, for battery pack 1, battery pack 2, and battery pack 3, at the start of charging, battery pack 1 has the highest state of charge and battery pack 3 has the lowest state of charge. Therefore, battery pack 3 can be determined as a charging battery pack first. When battery pack 3 is charged to the same state of charge as battery pack 2, battery packs 2 and 3 are determined as charging battery packs. When battery packs 2 and 3 are charged to the same state of charge as battery pack 1, battery packs 1, 2, and 3 are determined as charging battery packs.

[0128] It should be noted that by determining the battery pack with the smallest state of charge in the battery system as the rechargeable battery pack, the battery pack with the largest state of charge can be charged first, avoiding the simultaneous control of charging of multiple battery packs with different states of charge, which may lead to abnormal mutual charging between battery packs with different states of charge.

[0129] Step S503: charging the rechargeable battery pack.

[0130] For example, a control instruction can be sent to the charging switch corresponding to the rechargeable battery pack. The charging switch, in response to the control instruction, connects the rechargeable battery pack to the power supply device, allowing the power supply device to charge the rechargeable battery pack. The power supply device can be a photovoltaic charging power supply, an AC charging power supply, or other device. The switch can be a MOS transistor.

[0131] For example, if the rechargeable battery pack is battery pack 3, a control instruction may be sent to the charging MOS tube corresponding to the battery pack 3, and the charging MOS tube conducts the connection between the battery pack 3 and the power supply device according to the control instruction.

[0132] It should be noted that when the charging MOS transistor is turned on, the discharging MOS transistor connected in series with the charging MOS transistor is not turned on. Therefore, current can flow through the body diode of the discharging MOS transistor. When the current is large, for example, when the current is greater than a preset current threshold, the discharging MOS transistor can be controlled to be turned on to avoid damaging the discharging MOS transistor. The preset current threshold can be set based on the operating parameters of the body diode, and the specific value is not limited here.

[0133] In the above embodiment, by determining the battery pack with the smallest state of charge in the battery system as the rechargeable battery pack and charging the rechargeable battery pack, it is possible to avoid controlling the charging of multiple battery packs with different states of charge at the same time, thereby reducing the possibility of mutual charging between battery packs with different states of charge.

[0134] See also Figure 10 , Figure 10 It is a schematic flowchart of the sub-steps of another battery system control method provided in an embodiment of the present application, which may include the following steps S601 to S604.

[0135] Step S601: Acquire parameter information of each battery pack in the battery system, wherein the parameter information includes battery capacity and state of charge.

[0136] It can be understood that the above step S601 is the same as step S101 and will not be repeated here.

[0137] Step S602: When a charging instruction is detected, the battery pack with the smallest state of charge in the battery system is determined as a charging battery pack.

[0138] It can be understood that the above step S602 is the same as step S502 and will not be repeated here.

[0139] Step S603: Determine the total power requirement of the rechargeable battery pack, where the total power requirement is the sum of the power requirements of each rechargeable battery pack.

[0140] For example, the power requirements of each rechargeable battery pack can be read; then, the power requirements of each rechargeable battery pack are added together to obtain the total power requirements of the rechargeable battery pack. It should be noted that the power requirement refers to the power required by the rechargeable battery pack when charging.

[0141] For example, when the rechargeable battery pack is battery pack 1, the total power requirement of the rechargeable battery pack is the power requirement of battery pack 1. For another example, when the rechargeable battery packs are battery pack 1 and battery pack 2, the total power requirement of the rechargeable battery pack is the sum of the power requirements of battery pack 1 and battery pack 2.

[0142] Step S604: When the total required power value is greater than the maximum output power of the power supply device connected to the battery system, the rechargeable battery pack is charged based on the maximum output power.

[0143] It should be noted that the maximum output power of the power supply device is determined by the operating parameters of the power supply device, and the specific values ​​are not limited here.

[0144] For example, when the total power requirement is greater than the maximum output power of the power supply device connected to the battery system, the rechargeable battery pack is charged based on the maximum output power. When the total power requirement is less than or equal to the maximum output power of the power supply device, the rechargeable battery pack is charged based on the total power requirement.

[0145] For example, if the maximum output power of the power supply device is 5500W, the power demand of battery pack 1 is 4400W, the power demand of battery pack 2 is 1700W, and the power demand of battery pack 3 is 1700W, if the rechargeable battery pack is battery pack 3, the total power demand is 1700W, and battery pack 3 can be charged at a charging power of 1700W. For another example, if the rechargeable battery packs are battery packs 2 and 3, the total power demand is 3400W, and battery packs 2 and 3 can be charged at a charging power of 3400W. For another example, if the rechargeable battery packs are battery packs 1, 2, and 3, the total power demand is 7800W, which is greater than the maximum output power of the power supply device of 5500W, and battery packs 1, 2, and 3 can be charged at a charging power of 5500W.

[0146] In the above embodiment, by determining the total power requirement of the rechargeable battery pack, the rechargeable battery pack can be charged based on the maximum output power when the total power requirement is greater than the maximum output power of the power supply device, thereby ensuring high charging efficiency while avoiding overload operation of the power supply device.

[0147] A computer-readable storage medium is also provided in an embodiment of the present application. The computer-readable storage medium stores a computer program. The computer program includes program instructions. The processor executes the above program instructions to implement any battery system control method provided in the embodiment of the present application.

[0148] For example, when the program is loaded by the processor, the following steps may be performed:

[0149] Acquire parameter information of each battery pack in the battery system, wherein the parameter information includes battery capacity and state of charge; when a discharge instruction is detected, determine a target battery pack to be discharged based on the discharge power of the battery system and the battery capacity and state of charge of each battery pack in the battery system; and control the target battery pack to discharge.

[0150] The computer-readable storage medium may be an internal storage unit of the energy storage device described in the aforementioned embodiment, such as a hard disk or memory of the energy storage device. The computer-readable storage medium may also be an external storage device of the energy storage device, such as a plug-in hard disk, a smart memory card (SMC), a secure digital card (SD card), a flash card, etc. equipped on the energy storage device.

[0151] Furthermore, the computer-readable storage medium may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, programs required for at least one function, etc.; the data storage area may store data created according to each program, etc.

[0152] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present application, and such modifications or substitutions should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for controlling a battery system, characterized in that: A master control battery pack is applied to the battery system, wherein the battery system includes at least two battery packs, and the method includes: Obtaining parameter information of each battery pack in the battery system, the parameter information including battery capacity and state of charge; When a discharge instruction is detected, if the battery capacities of the battery packs in the battery system are different and the discharge power of the battery system is greater than or equal to a first discharge power threshold, determining the battery pack with the largest battery capacity as the target battery pack to be discharged; If the battery capacities of the battery packs in the battery system are different and the discharge power is less than the first discharge power threshold, determining the battery pack with the largest state of charge as the target battery pack; controlling the target battery pack to discharge; When it is detected that the discharge power of the battery system is less than a second discharge power threshold, the battery pack with the largest state of charge is controlled to discharge, and the second discharge power threshold is less than the first discharge power threshold.

2. The control method of the battery system according to claim 1, characterized in that: The determining a target battery pack to be discharged based on the discharge power of the battery system and the battery capacity and state of charge of each battery pack in the battery system includes: If the battery packs in the battery system have the same battery capacity but different states of charge, determining the battery pack with the largest state of charge as the target battery pack; If the battery capacities and states of charge of the battery packs in the battery system are the same, all the battery packs in the battery system are determined as the target battery packs.

3. The control method of the battery system according to claim 2, characterized in that: After determining all battery packs in the battery system as the target battery packs, controlling the target battery packs to discharge includes: If the discharge power is less than a first discharge power threshold, all battery packs in the battery system are controlled to discharge.

4. The control method of the battery system according to claim 1, characterized in that: The method further comprises: When a charging instruction is detected, determining a battery pack with the smallest state of charge in the battery system as a charging battery pack; The rechargeable battery pack is charged.

5. The control method of the battery system according to claim 4, characterized in that: The charging of the rechargeable battery pack includes: Determine a total power requirement of the rechargeable battery pack, where the total power requirement is the sum of the power requirements of each rechargeable battery pack; When the total required power value is greater than the maximum output power of the power supply device connected to the battery system, the rechargeable battery pack is charged based on the maximum output power.

6. An energy storage device, characterized in that: The energy storage device includes a battery pack, a memory and a processor; The memory is used to store computer programs; The processor is configured to implement the battery system control method according to any one of claims 1 to 5 when executing the computer program.

7. A battery system, characterized in that: The battery system includes at least two battery packs and a processor; The processor is used to implement the control method of the battery system according to any one of claims 1 to 5.

8. The battery system according to claim 7, characterized in that: The at least two battery packs include a main battery pack, and the processor is integrated in the main battery pack; or The battery system further includes a power conversion device for connecting to at least two battery packs respectively; the processor is integrated on the power conversion device.

Images