A method, system, and apparatus for failure handling of a battery system

Abstract

The application discloses a battery system fault processing method, system and device, and belongs to the technical field of battery fault processing. The open circuit voltage of each battery module in a current power supply period of a battery system is measured. The battery system is composed of N battery subsystems in parallel. Any battery subsystem is composed of a battery module and a controllable switch in series. The battery module with the open circuit voltage outside a preset voltage range is regarded as a fault battery module, and the controllable switch connected in series with the battery module is controlled to be disconnected. The remaining battery modules are regarded as standby battery modules. According to a control instruction, k standby battery modules are selected, and the controllable switches connected in series with the k standby battery modules are controlled to be connected in the next power supply period. Through the setting of the controllable switches, the open circuit voltage of the corresponding battery module can be measured when the controllable switch is disconnected, so that the fault determination is more accurate. Meanwhile, the fault battery module can be removed by disconnecting the controllable switch, and k battery modules can be selected again after the removal to ensure normal power supply.

Description

Technical Field

[0001] This invention relates to the field of battery fault handling technology, and in particular to a method, system and apparatus for handling battery system faults. Background Technology

[0002] Battery systems are widely used in new energy vehicles, energy storage power stations, and other fields due to their advantages such as high energy density and high power density. However, batteries themselves have high safety risks. During use, due to battery aging and factors such as overcharging, over-discharging, high-rate charging and discharging, overcooling, overheating, and inconsistency, internal short circuits, thermal runaway, and even fires or explosions can easily occur.

[0003] Existing battery system fault diagnosis methods primarily target battery systems composed of fixed series-parallel reconfigured battery modules. These methods face two main challenges: firstly, accurately and efficiently measuring or estimating the characteristic parameters of the battery modules to diagnose their fault states; secondly, even after diagnosing a fault, existing battery systems struggle to disconnect the faulty battery module and maintain its ability to supply power to the load after disconnection. Therefore, overcoming the challenges of "inaccurate measurement" and "inability to disconnect" inherent in traditional battery systems is a pressing issue in the field of battery system fault diagnosis. Summary of the Invention

[0004] The purpose of this application is to provide a method, system, and apparatus for handling battery system faults, which is applied in the field of battery fault handling technology. By setting a controllable switch, the open-circuit voltage of the corresponding battery module can be measured when the controllable switch is open, making the fault determination more accurate. At the same time, by opening the controllable switch, the faulty battery module can be disconnected, and after disconnection, k new battery modules can be selected to ensure normal power supply.

[0005] To address the aforementioned technical problems, this application provides a fault handling method for a battery system, comprising:

[0006] Measure the open-circuit voltage of each battery module in the current power supply cycle of the battery system. The battery system consists of N battery subsystems connected in parallel. Each battery subsystem consists of a battery module and a controllable switch connected in series. Each battery module consists of X batteries connected in series, where 2≤N and 1≤X.

[0007] The battery module with an open-circuit voltage outside the preset voltage range is identified as a faulty battery module, and the controllable switch connected in series with the faulty battery module is disconnected.

[0008] The battery module with an open-circuit voltage within the preset voltage range is used as the reserve battery module;

[0009] According to the control command, k reserve battery modules are selected from all the reserve battery modules, and in the next power supply cycle, the controllable switch connected in series with the selected k reserve battery modules is closed, and the controllable switch connected in series with the remaining reserve battery modules is opened, 1≤k≤N.

[0010] Preferably, measuring the open-circuit voltage of each battery module in the current power supply cycle of the battery system includes:

[0011] For the battery module connected in series with the disconnected controllable switch in the current power supply cycle, the open-circuit voltage of the battery module is directly measured.

[0012] For the battery module connected in series with the closed controllable switch in the current power supply cycle, the most recent historical open-circuit voltage of the battery module is selected as the open-circuit voltage in the current power supply cycle.

[0013] Preferably, for the battery module connected in series with the disconnected controllable switch in the current power supply cycle, directly measuring the open-circuit voltage of the battery module includes:

[0014] For the battery module connected in series with the disconnected controllable switch during the current power supply cycle, the open-circuit voltage of the battery module is directly measured by a voltage sensor.

[0015] Preferably, for the battery module connected in series with the disconnected controllable switch in the current power supply cycle, directly measuring the open-circuit voltage of the battery module includes:

[0016] For the battery module connected in series with the disconnected controllable switch in the current power supply cycle, the open-circuit voltage of the battery module is directly measured after a preset time period.

[0017] Preferably, after selecting the battery module with an open-circuit voltage within the preset voltage range as the reserve battery module, the method further includes:

[0018] In all the prepared battery modules, if it is detected that the controllable switch connected in series with the prepared battery module is closed for a preset number of consecutive power supply cycles, then in the next power supply cycle, the controllable switch that has been closed for the preset number of power supply cycles is opened.

[0019] Remove the reserve battery modules that are connected in series with the controllable switch that is closed in the consecutive preset number of power supply cycles from all the reserve battery modules, and proceed to the step of selecting k reserve battery modules from all the reserve battery modules according to the control command, and controlling the controllable switch connected in series with the selected k reserve battery modules to close in the next power supply cycle, and the controllable switch connected in series with the remaining reserve battery modules to open.

[0020] Preferably, the battery system consists of M power supply units connected in series, and each power supply unit consists of a master control switch and N battery subsystems connected in parallel, where 1 ≤ M;

[0021] Accordingly, k reserve battery modules are selected from all the reserve battery modules according to the control command, and in the next power supply cycle, the controllable switch connected in series with the selected k reserve battery modules is closed, and the controllable switch connected in series with the remaining reserve battery modules is opened, 1≤k≤N, including:

[0022] According to the control command, select h power supply units in the next power supply cycle and control their main control switch to open, while the main control switches of the remaining power supply units are closed, 1≤h≤M;

[0023] In any of the selected power supply units, k reserve battery modules are selected from all the reserve battery modules according to the control command, and in the next power supply cycle, the controllable switch connected in series with the selected k reserve battery modules is closed, and the controllable switch connected in series with the remaining reserve battery modules is opened, 1≤k≤N.

[0024] Preferably, k reserve battery modules are selected from all the reserve battery modules according to the control command, and in the next power supply cycle, the controllable switch connected in series with the selected k reserve battery modules is closed, and the controllable switch connected in series with the remaining reserve battery modules is opened, 1≤k≤N, including:

[0025] According to the control command, all the prepared battery modules are sorted from largest to smallest based on the open circuit voltage;

[0026] According to the control command, in the next power supply cycle, the controllable switch connected in series with the first k reserve battery modules is closed, and the controllable switch connected in series with the remaining reserve battery modules is opened, 1≤k≤N.

[0027] Preferably, after identifying the battery module with an open-circuit voltage outside a preset voltage range as a faulty battery module and disconnecting the controllable switch connected in series with the faulty battery module, the method further includes:

[0028] Continue measuring the open-circuit voltage of the faulty battery module;

[0029] When the open-circuit voltage of the faulty battery module recovers to the preset voltage range, and the module is again identified as the faulty battery module, an alarm maintenance message is issued.

[0030] To address the aforementioned technical problems, this application also provides a battery system fault handling system, comprising:

[0031] The open-circuit voltage measurement unit is used to measure the open-circuit voltage of each battery module in the current power supply cycle of the battery system. The battery system consists of N battery subsystems connected in parallel. Each battery subsystem consists of a battery module and a controllable switch connected in series. Each battery module consists of X batteries connected in series, where 2≤N and 1≤X.

[0032] A faulty battery module determination unit is used to identify battery modules with open-circuit voltages outside a preset voltage range as faulty battery modules and to control the controllable switch connected in series with the faulty battery module to disconnect.

[0033] A pre-selected battery module determination unit is used to select battery modules whose open-circuit voltage is within the preset voltage range as pre-selected battery modules.

[0034] A battery module selection unit is used to select k reserve battery modules from all the reserve battery modules according to control instructions, and in the next power supply cycle, control the controllable switch connected in series with the selected k reserve battery modules to close, and control the controllable switch connected in series with the remaining reserve battery modules to open, where 1≤k≤N.

[0035] To address the aforementioned technical problems, this application also provides a fault handling device for a battery system, comprising:

[0036] Memory, used to store computer programs;

[0037] A processor for executing the computer program to implement the steps of the fault handling method for the battery system.

[0038] This application provides a method, system, and apparatus for handling battery system faults, applicable to the field of battery fault handling technology. The method involves measuring the open-circuit voltage of each battery module in the current power supply cycle of the battery system. The battery system consists of N battery subsystems connected in parallel, each subsystem consisting of a battery module and a controllable switch connected in series. Battery modules with open-circuit voltages outside a preset range are identified as faulty battery modules, and the controllable switch connected in series with them is opened. The remaining battery modules are designated as reserve battery modules. According to control commands, k reserve battery modules are selected, and the controllable switch connected in series with them is closed in the next power supply cycle. By setting the controllable switch, the open-circuit voltage of the corresponding battery module can be measured when the controllable switch is open, resulting in more accurate fault determination. Furthermore, opening the controllable switch can disconnect the faulty battery module, and after disconnection, k new battery modules can be selected to ensure normal power supply. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 A flowchart illustrating a fault handling method for a battery system provided in this application;

[0041] Figure 2 This application provides a schematic diagram of the structure of a battery system;

[0042] Figure 3 A schematic diagram of another battery system provided in this application;

[0043] Figure 4 This application provides a schematic diagram of the structure of a battery system fault handling system.

[0044] Figure 5 This is a schematic diagram of the structure of a fault handling device for a battery system provided in this application. Detailed Implementation

[0045] The core of this application is to provide a method, system, and apparatus for handling battery system faults, which is applied in the field of battery fault handling technology. By setting a controllable switch, the open-circuit voltage of the corresponding battery module can be measured when the controllable switch is open, making the fault determination more accurate. At the same time, by opening the controllable switch, the faulty battery module can be disconnected, and after disconnection, k new battery modules can be selected to ensure normal power supply.

[0046] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] Figure 1 A flowchart illustrating a fault handling method for a battery system provided in this application includes:

[0048] S11: Measure the open-circuit voltage of each battery module in the current power supply cycle of the battery system. The battery system consists of N battery subsystems connected in parallel. Any battery subsystem consists of a battery module and a controllable switch connected in series. Any battery module consists of X batteries connected in series. 2≤N, 1≤X.

[0049] S12: Identify the battery module with an open-circuit voltage outside the preset voltage range as a faulty battery module and control the controllable switch connected in series with the faulty battery module to disconnect.

[0050] S13: Select the battery module with an open-circuit voltage within the preset voltage range as the backup battery module;

[0051] S14: Select k reserve battery modules from all reserve battery modules according to the control command, and in the next power supply cycle, control the controllable switch connected in series with the selected k reserve battery modules to close, and control the controllable switch connected in series with the remaining reserve battery modules to open, 1≤k≤N.

[0052] Battery systems are widely used in new energy vehicles, energy storage power stations, and other fields due to their advantages such as high energy density and high power density. However, batteries themselves have high safety risks. During use, due to battery aging and factors such as overcharging, over-discharging, high-rate charging and discharging, overcooling, overheating, and inconsistency, internal short circuits, thermal runaway, and even fires or explosions can easily occur.

[0053] Existing battery system fault diagnosis methods primarily target battery systems composed of fixed series-parallel reconfigured battery modules. These methods face two main challenges: firstly, accurately and efficiently measuring or estimating the characteristic parameters of the battery modules to diagnose their fault states; secondly, even after diagnosing a fault, existing battery systems struggle to disconnect the faulty battery module and maintain its ability to supply power to the load after disconnection. Therefore, overcoming the challenges of "inaccurate measurement" and "inability to disconnect" inherent in traditional battery systems is a pressing issue in the field of battery system fault diagnosis.

[0054] In existing technologies, the measurement or estimation of characteristic parameters (such as open-circuit voltage) of battery modules mainly employs three types of methods: knowledge-based, model-based, and data-driven. Knowledge-based battery fault diagnosis methods utilize expert systems and fault diagnosis trees for fault diagnosis; model-based fault diagnosis methods compare measured values ​​with output values ​​estimated by mathematical models to achieve fault detection and isolation; and data-driven fault diagnosis methods analyze and process operational data during power supply to complete fault detection and isolation. However, the accuracy of these methods in fault diagnosis is relatively low, and the isolation methods are complex.

[0055] To solve the above-mentioned technical problems, this application uses a controllable switch to directly measure the open-circuit voltage of the battery module, and determines whether the battery module is faulty based on the open-circuit voltage; and isolates the faulty battery module by disconnecting the controllable switch. The isolation method is simple, and after isolating the faulty battery module, k battery modules can be reselected to ensure the power supply of the battery system.

[0056] Specifically, the battery system structure diagram in S11 can be found by referring to... Figure 2 , Figure 2 Taking N=3 as an example, the battery system consists of 3 battery subsystems 1 connected in parallel. Each battery subsystem 1 consists of a battery module C connected in series with a controllable switch S. Each battery module C consists of X batteries connected in series. The number of battery subsystems 1 is greater than or equal to 2 to prevent the lack of a backup battery module C when a battery module C in a certain battery subsystem 1 fails. A battery module C can be composed of one or more batteries connected in series. The on / off state of the controllable switch S controls whether the battery module C connected in series with it is connected to the battery system.

[0057] It should also be noted that during a battery malfunction, changes in electricity are faster than changes in force, and changes in force are faster than changes in heat. Therefore, using electrical parameters as the basis for fault diagnosis is beneficial for timely detection of battery faults and preventing further escalation. In this application, considering the one-to-one positive correlation between open circuit voltage (OCV) and the SOC (State of Charge, ranging from 0 to 1; SOC = 0 indicates that battery module C is fully discharged, and SOC = 1 indicates that battery module C is fully charged) of battery module C, meaning that open circuit voltage directly reflects the remaining capacity of battery module C, an abnormal open circuit voltage indicates a high probability of a fault in battery module C, the selected electrical parameter is the open circuit voltage of battery module C, which is used as the basis for fault diagnosis of battery module C.

[0058] In S12 and S13, the open-circuit voltage of each battery cell or module has a normal preset voltage range. If the measured open-circuit voltage is within the preset voltage range, the battery module C is considered to be in normal condition and can be used as a backup battery module. If the measured open-circuit voltage is outside the preset voltage range, that is, below the lower threshold of the preset voltage range or above the upper threshold of the preset voltage range, the battery module C is considered to be in abnormal condition and can be used as a faulty battery module, which needs to be disconnected immediately.

[0059] The disconnection method is as follows: disconnect the controllable switch S connected in series with the faulty battery module so that the battery system does not pass through the faulty battery module when supplying power, thereby achieving disconnection. The disconnection method of the auxiliary controllable switch S does not require changes to the circuit structure, is simpler, and can quickly disconnect the faulty battery module in microseconds.

[0060] Furthermore, assuming that the preset voltage range of the normal open-circuit voltage of each battery cell is (V1, V2), and each battery module C contains X cells, i.e. X batteries connected in series, then the preset voltage range of the normal open-circuit voltage of battery module C is (X*V1, X*V2). If the measured open-circuit voltage is not within this range, it is determined that the battery module C may be abnormal.

[0061] In S14, the battery module C selected for the next power supply cycle is determined by the open-circuit voltage of battery module C obtained in the current power supply cycle. Furthermore, based on all the reserve battery modules, k reserve battery modules are selected to dynamically reconfigure the battery system, isolating the influence of faulty battery modules and improving the self-reconstruction capability of the battery system.

[0062] Among them, the control command is related to the specific application scenario. According to the preset needs of the control command, k battery modules C are selected from the total N battery modules C (i.e., the N-to-k working mode) for discharge, that is, the controllable switch S connected in series with the k battery modules C is closed.

[0063] Furthermore, the battery system manages each battery module C individually via a controllable switch S. While disconnecting the controllable switch S isolates faults, the non-faulty parts of the battery system can still maintain normal power supply, preventing the entire battery system from shutting down due to a single battery module C failure, thereby improving the energy utilization rate of the battery system. For example, in the N-select-k operating mode, if one of the battery modules C fails, disconnecting it and selecting k from the remaining N-1 battery modules C for discharge ensures the normal operation of the battery system.

[0064] Furthermore, the battery system involved in this application is equivalent to a dynamically reconfigurable battery network (DRBN), which deeply couples a large number of power electronic controllable switches S with battery modules C, enabling dynamic reconfiguration of the battery network topology. Compared to traditional fixed series-parallel reconfiguration battery systems, the battery system involved in this application has more flexible control methods and higher energy efficiency, and can achieve precise isolation of any battery module C.

[0065] In summary, this application provides a method for handling battery system faults, which is applied in the field of battery fault handling technology. The method involves measuring the open-circuit voltage of each battery module C in the current power supply cycle of the battery system. The battery system consists of N battery subsystems 1 connected in parallel, and each battery subsystem 1 consists of a battery module C and a controllable switch S connected in series. Battery modules C whose open-circuit voltage is outside a preset voltage range are identified as faulty battery modules, and the controllable switch S connected in series with them is opened. The remaining battery modules C are designated as reserve battery modules. According to control commands, k reserve battery modules are selected, and the controllable switch S connected in series with them is closed in the next power supply cycle. By setting the controllable switch S, the open-circuit voltage of the corresponding battery module C can be measured when the controllable switch S is open, resulting in more accurate fault determination. Furthermore, opening the controllable switch S can disconnect the faulty battery module, and after disconnection, k new battery modules C can be selected to ensure normal power supply.

[0066] Based on the above embodiments:

[0067] As a preferred embodiment, measuring the open-circuit voltage of each battery module C in the current power supply cycle of the battery system includes:

[0068] For the battery module C connected in series with the disconnected controllable switch S during the current power supply cycle, directly measure the open-circuit voltage of the battery module C.

[0069] For the battery module C connected in series with the closed controllable switch S in the current power supply cycle, the most recent historical open-circuit voltage of the battery module C is selected as the open-circuit voltage in the current power supply cycle.

[0070] This embodiment specifies how to measure the open-circuit voltage of each battery module C during the current power supply cycle. The battery system measures the open-circuit voltage of each battery module C in real time during operation. When battery module C is connected to the battery system for discharge, because current flows through battery module C, only the operating voltage of battery module C can be measured, which is the open-circuit voltage minus the voltage drop across the internal resistance of battery module C. When battery module C is disconnected from the battery system, the current flowing through battery module C is zero, and the voltage drop across the internal resistance is zero. Only then does the terminal voltage of battery module C equal the open-circuit voltage.

[0071] Considering that the measurement of open circuit voltage should not affect the normal discharge of the battery system, and the method for measuring open circuit voltage is to disconnect the controllable switch S, the best time to measure is when the battery module C is not selected, that is, it is not in a discharging state, and the controllable switch S connected in series with it is in an open state.

[0072] For example, for N battery modules C connected in parallel, k modules are selected to be connected to the battery system in each power supply cycle (i.e., N-to-k operating mode), and the remaining Nk battery modules C are disconnected from the battery system (the remaining Nk battery modules C include faulty battery modules and remaining reserve battery modules). The open-circuit voltage of these Nk battery modules C can then be measured. For the k battery modules C that are discharging, their open-circuit voltage can be taken from the measurement in the previous power supply cycle. If the battery module C was not selected in the previous power supply cycle, the open-circuit voltage measured in the previous power supply cycle can be selected; if the battery module C was still selected in the previous power supply cycle, but was not selected in the previous two power supply cycles, the open-circuit voltage measured in the previous two power supply cycles can be selected. In other words, the most recent open-circuit voltage from the historical measurements of the battery module C is selected as the open-circuit voltage for the current power supply cycle, thus updating the open-circuit voltage for the current power supply cycle. Since each power supply cycle is very short and the open-circuit voltage changes little, the above method can achieve rapid updates of the open-circuit voltage of each battery module C within the allowable error range.

[0073] It should also be noted that, compared to the fixed series-parallel connection between battery modules C in traditional battery systems, which makes it impossible to accurately measure the open-circuit voltage of each battery module C and only allows measurement of the operating voltage, this application allows for the measurement of the open-circuit voltage of the battery module C connected in series with the controllable switch S during battery system operation. This is more accurate, and the fault diagnosis performed accordingly is also more precise.

[0074] In summary, obtaining real-time and more accurate open-circuit voltage allows for more precise fault diagnosis.

[0075] As a preferred embodiment, for the battery module C connected in series with the disconnected controllable switch S during the current power supply cycle, the open-circuit voltage of the battery module C is directly measured, including:

[0076] For the battery module C connected in series with the disconnected controllable switch S during the current power supply cycle, the open-circuit voltage of the battery module C is directly measured by a voltage sensor.

[0077] In this embodiment, the open-circuit voltage of the battery module C that is not connected to the battery system can be obtained by directly measuring the voltage across the two ends of the battery module C using a voltage sensor. This operation is simple and easy to implement.

[0078] As a preferred embodiment, for the battery module C connected in series with the disconnected controllable switch S during the current power supply cycle, the open-circuit voltage of the battery module C is directly measured, including:

[0079] For the battery module C connected in series with the disconnected controllable switch S during the current power supply cycle, the open-circuit voltage of the battery module C is directly measured after a preset time period.

[0080] In this embodiment, since the battery module C contains an equivalent second-order RC circuit, there is a transient process of a preset time period after it is disconnected from the battery system. Only after the transient process ends will the voltage across the battery module C be equal to the open-circuit voltage. Therefore, a preset time delay needs to be added when measuring the open-circuit voltage, for example, 10ms. That is, the voltage across the battery module C is measured 10ms after it is disconnected from the battery system. Only then will the voltage value obtained be approximately equal to the open-circuit voltage of the battery module C.

[0081] In summary, by setting a delay time, the open-circuit voltage can be measured more accurately.

[0082] In a preferred embodiment, after selecting the battery module C with an open-circuit voltage within a preset voltage range as the backup battery module, the method further includes:

[0083] In all backup battery modules, if it is detected that the controllable switch S connected in series with the backup battery module is closed for a preset number of consecutive power supply cycles, then in the next power supply cycle, the controllable switch S that has been closed for a preset number of power supply cycles will be opened.

[0084] Remove the reserve battery modules that are connected in series with the controllable switch S that is closed for a preset number of consecutive power supply cycles from all the reserve battery modules, and proceed to the step of selecting k reserve battery modules from all the reserve battery modules according to the control command, and controlling the controllable switch connected in series with the selected k reserve battery modules to close in the next power supply cycle, and the controllable switch connected in series with the remaining reserve battery modules to open.

[0085] In this embodiment, after eliminating faulty battery modules and identifying all backup battery modules, it is also necessary to consider whether any backup battery module discharges for a preset number of consecutive power supply cycles, i.e., the controllable switch S connected in series with it closes for a preset number of consecutive power supply cycles. In this case, the backup battery module operates continuously for too long, and its updated open-circuit voltage is the open-circuit voltage before the preset number of consecutive power supply cycles, which is no longer real-time, and the fault determination based on the power supply voltage is inaccurate.

[0086] Specifically, if a backup battery module is selected for a preset number of consecutive power supply cycles and the controllable switch S remains closed, its open-circuit voltage cannot be updated when the controllable switch S is opened. In this case, the backup battery module is deemed to have a fault risk, and it cannot be selected for discharge in the next power supply cycle. Therefore, the controllable switch S connected in series with it needs to be forcibly opened to sample and measure its open-circuit voltage. Simultaneously, the backup battery module is removed from all backup battery modules to prevent it from being selected and having its controllable switch S closed again when selecting k backup battery modules from all backup battery modules.

[0087] In summary, the requirement to update the open-circuit voltage in this implementation ensures the real-time nature of the open-circuit voltage. As a result, the most recent historical open-circuit voltage of the battery module C connected to the battery system obtained in the current power supply cycle is real-time and effective, reducing the probability of misjudgment when using open-circuit voltage for fault detection.

[0088] In a preferred embodiment, the battery system consists of M power supply units connected in series, and each power supply unit consists of a master control switch and N battery subsystems connected in parallel, where 1 ≤ M;

[0089] Accordingly, k reserve battery modules are selected from all reserve battery modules according to the control command, and in the next power supply cycle, the controllable switch S connected in series with the selected k reserve battery modules is closed, and the controllable switch S connected in series with the remaining reserve battery modules is opened, 1≤k≤N, including:

[0090] According to the control command, select h power supply units in the next power supply cycle and control their main control switch to open, while the main control switches of the remaining power supply units are closed, 1≤h≤M;

[0091] In any selected power supply unit, k backup battery modules are selected from all backup battery modules according to the control command, and in the next power supply cycle, the controllable switch S connected in series with the selected k backup battery modules is closed, and the controllable switch S connected in series with the remaining backup battery modules is opened, 1≤k≤N.

[0092] Considering the power demand, the battery system can be composed of M*N battery modules C. For details, please refer to... Figure 3 , Figure 3 Taking M=N=3 as an example, the battery system consists of 3 power supply units 2 connected in series, and each power supply unit 2 consists of a master control switch S0 and 3 battery subsystems 1 connected in parallel.

[0093] When rebuilding the battery system in the next power supply cycle, according to the control command, h power supply units 2 are first selected for power supply. The method for selecting power supply units 2 is as follows: the main control switch S0 in power supply unit 2 is opened, and the power supply will inevitably pass through a portion of the battery subsystems 1 in power supply unit 2. The method for not selecting power supply units 2 is as follows: the main control switch S0 in power supply unit 2 is closed, and the power supply current directly passes through the circuit where the main control switch S0 is located, short-circuiting all battery subsystems 1 in power supply unit 2. Furthermore, the main control switch S0 can provide a current path when N parallel battery modules C are simultaneously disconnected.

[0094] Secondly, k battery modules C are selected in each of the selected power supply units 2 and connected to the battery system. The specific process is the same as in the above embodiment, and will not be repeated here.

[0095] In summary, the battery system composed of M*N battery modules C expands the power supply capacity and can meet greater power supply demands.

[0096] In a preferred embodiment, k reserve battery modules are selected from all reserve battery modules according to control commands, and in the next power supply cycle, the controllable switch S connected in series with the selected k reserve battery modules is closed, while the controllable switch S connected in series with the remaining reserve battery modules is opened, 1≤k≤N, including:

[0097] According to the control instructions, all prepared battery modules are sorted from largest to smallest based on their open-circuit voltage;

[0098] According to the control command, in the next power supply cycle, the controllable switch S connected in series with the first k reserve battery modules is closed, and the controllable switch S connected in series with the remaining reserve battery modules is opened, 1≤k≤N.

[0099] In this embodiment, since there is a one-to-one positive correlation between the open-circuit voltage and the SOC (State of Charge, which ranges from 0 to 1; when SOC = 0, it indicates that the battery module C is fully discharged; when SOC = 1, it indicates that the battery module C is fully charged) of the battery module C, the open-circuit voltage can directly reflect the remaining capacity of the battery module C. Therefore, when selecting k backup battery modules, the backup battery modules with larger open-circuit voltages can be selected to be connected to the battery system for discharge based on the magnitude of the open-circuit voltage. In other words, the backup battery modules with larger remaining capacity are preferentially selected for discharge to prevent the remaining capacity of the backup battery modules with smaller remaining capacity from becoming too small and the corresponding open-circuit voltage from falling outside the preset voltage range, which would cause a fault. This ensures the orderly discharge of each battery module C in the battery system and reduces the failure rate.

[0100] In a preferred embodiment, after designating the battery module C with an open-circuit voltage outside a preset voltage range as a faulty battery module and controlling the controllable switch S connected in series with the faulty battery module to disconnect, the method further includes:

[0101] Continue measuring the open-circuit voltage of the faulty battery module;

[0102] If the open-circuit voltage of the faulty battery module returns to the preset voltage range, and the module is again identified as a faulty battery module, an alarm maintenance message will be issued.

[0103] The possible reasons for the failure of battery module C are: first, the previous abnormal open-circuit voltage may have been caused by electromagnetic interference in the battery system, and battery module C itself did not fail; second, the previous failure was reversible, such as insulation damage caused by a sudden increase in power. After battery module C was isolated for a period of time, the insulation was restored, and battery module C returned to normal.

[0104] Therefore, it is necessary to continue to detect the open circuit voltage of the faulty battery module. If the open circuit voltage of the faulty battery module recovers to the normal level (within the preset voltage range), a second diagnosis is required to further determine whether the faulty battery module can be used normally. If the open circuit voltage is still at an abnormal level (outside the preset voltage range), it indicates that the fault of the faulty battery module is irreversible, and an alarm maintenance message needs to be issued to notify the staff to carry out maintenance.

[0105] Specifically, the secondary diagnostic method is as follows: After the open-circuit voltage of the faulty battery module recovers for a period of time (e.g., 20-30 power supply cycles), the faulty battery module is reclassified as a backup battery module and tentatively connected to the battery system. The trend of its open-circuit voltage is then observed again. If the open-circuit voltage is again at an abnormal level (outside the preset voltage range) and is again identified as a faulty battery module, it needs to be immediately disconnected from the battery system. At the same time, it is determined that a fault has indeed occurred, and an alarm maintenance message needs to be issued to notify the staff for repair. If the open-circuit voltage remains at a normal level (within the preset voltage range), it indicates that the faulty battery module is in normal condition and can continue to be used. This indicates that the previous judgment of the faulty battery module was incorrect, or that the fault of the faulty battery module is reversible and has self-recovered. In this case, the faulty battery module can participate in discharge normally.

[0106] In summary, we continue to monitor the open-circuit voltage of the faulty battery module and perform a second diagnosis after the open-circuit voltage recovers to the normal level to prevent misdiagnosis of the faulty battery module.

[0107] Please refer to Figure 4 , Figure 4 A schematic diagram of a fault handling system for a battery system provided in this application includes:

[0108] The open-circuit voltage measurement unit 21 is used to measure the open-circuit voltage of each battery module C in the current power supply cycle of the battery system. The battery system is composed of N battery subsystems 1 connected in parallel. Each battery subsystem 1 is composed of battery module C and controllable switch S connected in series. Each battery module C is composed of X batteries connected in series, 2≤N, 1≤X.

[0109] The faulty battery module determination unit 22 is used to identify the battery module C with an open circuit voltage outside the preset voltage range as a faulty battery module and control the controllable switch S connected in series with the faulty battery module to disconnect.

[0110] The backup battery module determination unit 23 is used to select the battery module C with an open circuit voltage within a preset voltage range as the backup battery module.

[0111] The battery module selection unit 24 is used to select k reserve battery modules from all reserve battery modules according to the control command, and control the controllable switch S connected in series with the selected k reserve battery modules to close in the next power supply cycle, and the controllable switch S connected in series with the remaining reserve battery modules to open, 1≤k≤N.

[0112] For a description of the battery system fault handling system provided in this application, please refer to the above embodiments; further details will not be repeated here.

[0113] As a preferred embodiment, the open-circuit voltage measurement unit 21 includes:

[0114] The direct measurement unit is used to directly measure the open-circuit voltage of the battery module C, which is connected in series with the disconnected controllable switch S during the current power supply cycle.

[0115] The history selection unit is used to select the most recent historical open-circuit voltage of the battery module C, which is connected in series with the closed controllable switch S in the current power supply cycle, as the open-circuit voltage in the current power supply cycle.

[0116] As a preferred embodiment, the direct measurement unit is specifically used for:

[0117] For the battery module C connected in series with the disconnected controllable switch S during the current power supply cycle, the open-circuit voltage of the battery module C is directly measured by a voltage sensor.

[0118] As a preferred embodiment, the direct measurement unit is specifically used for:

[0119] For the battery module C connected in series with the disconnected controllable switch S during the current power supply cycle, the open-circuit voltage of the battery module C is directly measured after a preset time period.

[0120] As a preferred embodiment, it also includes:

[0121] The detection unit is used, after the pre-battery module determination unit 23, to detect that if the controllable switch S connected in series with the pre-battery module is closed for a preset number of consecutive power supply cycles in all pre-battery modules, then in the next power supply cycle, the controllable switch S that has been closed for a preset number of power supply cycles will be opened.

[0122] The backup battery module re-determination unit is used to remove backup battery modules that are connected in series with the controllable switch S that is closed in a consecutive preset number of power supply cycles from all backup battery modules, and then enter the battery module selection unit 24.

[0123] In a preferred embodiment, the battery system consists of M power supply units connected in series, and each power supply unit consists of a master control switch and N battery subsystems connected in parallel, where 1 ≤ M;

[0124] Correspondingly, the battery module selection unit 24 includes:

[0125] The power supply unit selection unit is used to select h power supply units in the next power supply cycle according to the control command and control their main control switch to be opened, while the main control switches of the remaining power supply units are closed, 1≤h≤M;

[0126] The battery module selection unit in the power supply unit is used to select k reserve battery modules from all reserve battery modules according to the control command in any selected power supply unit, and control the controllable switch S connected in series with the selected k reserve battery modules to close in the next power supply cycle, and the controllable switch S connected in series with the remaining reserve battery modules to open, 1≤k≤N.

[0127] In a preferred embodiment, the battery module selection unit 24 includes:

[0128] The sorting unit is used to sort all the prepared battery modules from largest to smallest according to the open circuit voltage according to the control command.

[0129] The battery module selection unit based on sorting is used to control the controllable switch S connected in series with the first k reserve battery modules to close and the controllable switch S connected in series with the remaining reserve battery modules to open in the next power supply cycle according to the control command, where 1≤k≤N.

[0130] As a preferred embodiment, it also includes:

[0131] The continuing measurement unit is used to continue measuring the open-circuit voltage of the faulty battery module after the faulty battery module determination unit 22.

[0132] The alarm and maintenance unit is used to issue alarm and maintenance information when the open-circuit voltage of the faulty battery module recovers to the preset voltage range and is determined to be a faulty battery module again.

[0133] Please refer to Figure 5 , Figure 5 A schematic diagram of a fault handling device for a battery system provided in this application includes:

[0134] Memory 31 is used to store computer programs;

[0135] Processor 32 is used to execute computer programs to implement the steps of a fault handling method for the battery system.

[0136] For a description of the battery system fault handling device provided in this application, please refer to the above embodiments; further details will not be repeated here.

[0137] It should be noted that, in this specification, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0138] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fault handling method for a battery system, characterized in that, include: The open-circuit voltage of each battery module in the current power supply cycle of the battery system is measured. The battery system consists of N battery subsystems connected in parallel. Each battery subsystem consists of a battery module and a controllable switch connected in series. Each battery module consists of X batteries connected in series, where 2≤N and 1≤X. The open-circuit voltage directly reflects the remaining capacity of the battery module. The measurement of the open-circuit voltage of each battery module in the current power supply cycle of the battery system includes: For the battery module connected in series with the disconnected controllable switch in the current power supply cycle, the open-circuit voltage of the battery module is directly measured; the direct measurement of the open-circuit voltage of the battery module connected in series with the disconnected controllable switch in the current power supply cycle includes: for the battery module connected in series with the disconnected controllable switch in the current power supply cycle, after a preset time period, the open-circuit voltage of the battery module is directly measured; For the battery module connected in series with the closed controllable switch in the current power supply cycle, the most recent historical open-circuit voltage of the battery module is selected as the open-circuit voltage in the current power supply cycle. The battery module with an open-circuit voltage outside the preset voltage range is identified as a faulty battery module, and the controllable switch connected in series with the faulty battery module is disconnected. The battery module with an open-circuit voltage within the preset voltage range is used as the reserve battery module; According to the control command, k reserve battery modules are selected from all the reserve battery modules, and in the next power supply cycle, the controllable switch connected in series with the selected k reserve battery modules is closed, and the controllable switch connected in series with the remaining reserve battery modules is opened, 1≤k≤N; wherein, selecting k reserve battery modules according to the control command and closing the controllable switch connected in series with the selected k reserve battery modules in the next power supply cycle, and opening the controllable switch connected in series with the remaining reserve battery modules, 1≤k≤N, includes: sorting all the reserve battery modules from largest to smallest according to the open circuit voltage according to the control command; and closing the controllable switch connected in series with the first k reserve battery modules in the next power supply cycle, and opening the controllable switch connected in series with the remaining reserve battery modules, 1≤k≤N; Continue measuring the open-circuit voltage of the faulty battery module; When the open-circuit voltage of the faulty battery module recovers to the preset voltage range, and the module is again identified as the faulty battery module, an alarm maintenance message is issued.

2. The fault handling method for a battery system as described in claim 1, characterized in that, For the battery module connected in series with the disconnected controllable switch in the current power supply cycle, the open-circuit voltage of the battery module is directly measured, including: For the battery module connected in series with the disconnected controllable switch during the current power supply cycle, the open-circuit voltage of the battery module is directly measured by a voltage sensor.

3. The fault handling method for a battery system as described in claim 1, characterized in that, After selecting the battery module with an open-circuit voltage within the preset voltage range as the candidate battery module, the method further includes: In all the prepared battery modules, if it is detected that the controllable switch connected in series with the prepared battery module is closed for a preset number of consecutive power supply cycles, then in the next power supply cycle, the controllable switch that has been closed for the preset number of power supply cycles is opened. Remove the reserve battery modules that are connected in series with the controllable switch that is closed in the consecutive preset number of power supply cycles from all the reserve battery modules, and proceed to the step of selecting k reserve battery modules from all the reserve battery modules according to the control command, and controlling the controllable switch connected in series with the selected k reserve battery modules to close in the next power supply cycle, and the controllable switch connected in series with the remaining reserve battery modules to open.

4. The fault handling method for a battery system as described in claim 1, characterized in that, The battery system consists of M power supply units connected in series, and each power supply unit consists of a master control switch and N battery subsystems connected in parallel, where 1≤M; Accordingly, k reserve battery modules are selected from all the reserve battery modules according to the control command, and in the next power supply cycle, the controllable switch connected in series with the selected k reserve battery modules is closed, and the controllable switch connected in series with the remaining reserve battery modules is opened, 1≤k≤N, including: According to the control command, select h power supply units in the next power supply cycle and control their main control switch to open, while the main control switches of the remaining power supply units are closed, 1≤h≤M; In any of the selected power supply units, k reserve battery modules are selected from all the reserve battery modules according to the control command, and in the next power supply cycle, the controllable switch connected in series with the selected k reserve battery modules is closed, and the controllable switch connected in series with the remaining reserve battery modules is opened, 1≤k≤N.

5. A fault handling system for a battery system, characterized in that, include: The open-circuit voltage measurement unit is used to measure the open-circuit voltage of each battery module in the current power supply cycle of the battery system. The battery system consists of N battery subsystems connected in parallel. Each battery subsystem consists of a battery module and a controllable switch connected in series. Each battery module consists of X batteries connected in series, where 2≤N and 1≤X. The open-circuit voltage directly reflects the remaining capacity of the battery module. The open-circuit voltage measurement unit includes: a direct measurement unit and a historical selection unit; The direct measurement unit is used to directly measure the open-circuit voltage of the battery module connected in series with the disconnected controllable switch during the current power supply cycle. The direct measurement unit is specifically used to: for the battery module connected in series with the disconnected controllable switch in the current power supply cycle, after a preset time period, directly measure the open circuit voltage of the battery module; The historical selection unit is used to select the most recent historical open-circuit voltage of the battery module connected in series with the closed controllable switch in the current power supply cycle as the open-circuit voltage in the current power supply cycle. A faulty battery module determination unit is used to identify battery modules with open-circuit voltages outside a preset voltage range as faulty battery modules and to control the controllable switch connected in series with the faulty battery module to disconnect. A pre-selected battery module determination unit is used to select battery modules whose open-circuit voltage is within the preset voltage range as pre-selected battery modules. A battery module selection unit is used to select k reserve battery modules from all the reserve battery modules according to control instructions, and control the controllable switch connected in series with the selected k reserve battery modules to close and the controllable switch connected in series with the remaining reserve battery modules to open in the next power supply cycle, where 1≤k≤N; The battery module selection unit includes: a sorting unit, used to sort all the reserve battery modules from largest to smallest according to the open-circuit voltage according to the control command; and a sorted battery module selection unit, used to control the controllable switch connected in series with the first k reserve battery modules to close and the controllable switch connected in series with the remaining reserve battery modules to open in the next power supply cycle according to the control command, where 1≤k≤N. The continuing measurement unit is used to continue measuring the open-circuit voltage of the faulty battery module after the faulty battery module determination unit. The alarm and maintenance unit is used to issue alarm and maintenance information when the open-circuit voltage of the faulty battery module recovers to the preset voltage range and is determined to be the faulty battery module again.

6. A fault handling device for a battery system, characterized in that, include: Memory, used to store computer programs; A processor for executing the computer program to implement the steps of the fault handling method for the battery system as claimed in any one of claims 1 to 4.

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