Lithium ion power battery rotation rest balance topology for electric ship and control method

Abstract

The invention discloses a lithium ion power battery rotation rest balance topology for an electric ship and a control method, and relates to the technical field of management control in a lithium ion battery system for the electric ship. According to the electric ship lithium ion power battery rotation rest balance topology and the control method, a lithium ion power battery topology structure is constructed, an operation group and a candidate group are dynamically configured, a rotation rest priority index is calculated based on operation state time sequence data, batteries to be subjected to rotation rest are accurately judged, substitute batteries are intelligently screened, and safe and controllable topology switching is executed; according to the method, the dynamic configuration of the operation groups and the candidate groups is realized by constructing the battery topological structure mapping table, defining the connection relationship and the scheduling condition and combining the operation fitness score, so that the scientificity of the battery grouping management and the stability of the system operation are improved; the fault risk is effectively reduced; and the service life of the battery system is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of management and control in electric ship lithium-ion battery systems, and specifically to a topology and control method for the rotation balance of electric ship lithium-ion power batteries. Background Art

[0002] With the rapid development of electric ship technology, lithium-ion power batteries, as the main energy supply devices, are widely used in various new energy ships. During the navigation of electric ships, high requirements are put forward for the power supply continuity, safety, and life stability of the battery system.

[0003] Since the power system of an electric ship usually consists of multiple battery packs, these batteries will have different degrees of performance degradation due to factors such as uneven load, different charge and discharge frequencies, and thermal accumulation differences during operation, which will in turn affect the reliability and energy efficiency level of the whole ship's operation. To improve the overall service life and operation efficiency of the battery system, the concept of battery rotation management has been gradually proposed, that is, by monitoring and regulating the operating states of multiple battery units, realizing the dynamic switching between the power supply battery and the standby battery, enabling each battery unit to have the opportunity to work alternately, and reducing the performance loss caused by continuous high-load operation.

[0004] The prior art, such as a topology and control method for the rotation balance of electric ship lithium-ion power batteries disclosed in the invention patent application with the publication number of CN110970969B, includes multiple (≥2) battery clusters directly connected in parallel to the DC bus. Each battery cluster is composed of multiple (≥2) battery modules connected in series. Each battery module includes a battery pack, and the battery pack is composed of 1 to 3 single cells connected in series. After each battery pack is connected in series with an MOS tube Q1 with a reverse diode D1, it is connected in parallel with an MOS tube Q2 with a reverse diode D2; its control method is also disclosed. The present invention can achieve the rotation balance between the series battery modules inside the battery cluster and the equalization control between the parallel battery clusters, with a high degree of modularization and high equalization efficiency, and can maximize the charge and discharge power of the power battery, avoiding the "barrel" effect caused by battery inconsistency.

[0005] Based on the above solutions, it is found that the limitations of the existing technology at least include the following problems. In the rotation management process of electric ship lithium-ion power batteries, there is a lack of stability and safety control mechanisms for battery switching operations. Most of the battery module switching relies on directly controlling the on-off devices or MOS logic units for forced switching. There is no clear distinction between the operating group and the standby group structures, and there is no state confirmation and fault fallback mechanism during the switching process. This method can still operate under static conditions, but under complex dynamic working conditions, such as sudden changes in the propulsion load of the electric ship, drastic changes in the cabin environment, inconsistent battery states, etc., it is extremely easy to cause switching failures due to electrical transient shocks, delayed response of the backup battery, or poor communication, which in turn leads to problems such as abnormal bus voltage, out-of-step of the control system, or power supply interruption. More importantly, the existing technology generally lacks the ability to monitor the process of battery switching behavior and record data. Once a failure occurs, it is difficult to trace and determine the cause, which limits the scalability and intelligent evolution ability of the system. Therefore, how to achieve a controllable, stable, and safe battery switching mechanism for the topological structure is one of the core bottlenecks in the current battery rotation control technology. Summary of the Invention

[0006] Aiming at the deficiencies of the existing technology, the present invention provides a rotation balance topology and control method for electric ship lithium-ion power batteries, which solves the problems of lack of topological control, safety buffer, and state confirmation mechanisms in the battery switching process of the existing technology, resulting in unstable switching, high risk of misconnection, and poor reliability of system operation.

[0007] To achieve the above objectives, the present invention is realized through the following technical solutions: A rotation balance topology and control method for electric ship lithium-ion power batteries, comprising the following steps: Based on a number of lithium-ion power batteries in an electric ship, establish a lithium-ion power battery topological structure, and configure an operating group and a standby group, both of which include a number of lithium-ion power batteries; when the electric ship is operating, continuously obtain the operating state time series data of each lithium-ion power battery in the operating group, and analyze the rotation priority index of each lithium-ion power battery in the operating group; for the rotation priority index of each lithium-ion power battery in the operating group, respectively based on a preset rotation rule, determine whether there is a lithium-ion power battery in the operating group that meets the rotation condition, and mark it as a battery to be rotated; if there is a battery to be rotated in the operating group, determine a backup battery from the standby group, and execute a topological switching measure.

[0008] Further, the specific steps for establishing the topological structure of the lithium-ion power battery for the electric boat are as follows: Obtain the basic structure information of each lithium-ion power battery in the electric boat and establish a list of lithium-ion power battery nodes. The basic structure information includes battery number, voltage level, rated capacity, and supported communication protocol; conduct a compatibility analysis on each lithium-ion power battery node in the list of lithium-ion power battery nodes and generate a topological structure mapping table.

[0009] Further, the specific steps for configuring the operating group and the standby group are as follows: Obtain the current status data of each lithium-ion power battery in the topological structure mapping table and analyze the operating fitness score of each lithium-ion power battery. The current status data includes remaining power status, health status evaluation value, battery case temperature value, temperature rise rate, and continuous power supply duration; obtain the operating fitness score threshold and compare and analyze it with the operating fitness score of each lithium-ion power battery respectively. Configure the lithium-ion power batteries with an operating fitness score higher than the operating fitness score threshold into the operating group, and configure the lithium-ion power batteries with an operating fitness score lower than or equal to the operating fitness score threshold into the standby group.

[0010] Further, the operating status time series data includes the amplitude of the supply current change, the amplitude of the voltage change, the temperature rise speed, the vertical vibration acceleration, and the relative humidity inside the cabin and the amplitude of the cabin air pressure change within a set area at several time points.

[0011] Further, the specific steps for analyzing the rotation priority index of each lithium-ion power battery in the operating group are as follows: Read the operating status time series data of each lithium-ion power battery in the operating group and analyze the operating status time series feature set of each lithium-ion power battery in the operating group. The operating status time series feature set includes the average amplitude of the supply current change, the average amplitude of the voltage change, the average temperature rise speed, the average vertical vibration acceleration, and the average relative humidity inside the cabin and the average amplitude of the cabin air pressure change within a set area; conduct a comprehensive analysis on the operating status time series feature set of each lithium-ion power battery in the operating group respectively to obtain the rotation priority index of each lithium-ion power battery in the operating group.

[0012] Further, the specific formula for calculating the rotation priority index of a certain lithium-ion power battery in the operating group is as follows: ; where is the rotation priority index of a certain lithium-ion power battery, is the average amplitude of the supply current change of a certain lithium-ion power battery, is the current change influence coefficient stored in the database, is the average amplitude of the voltage change of a certain lithium-ion power battery, is the average temperature rise speed of a certain lithium-ion power battery, is the average vertical vibration acceleration of a certain lithium-ion power battery, is the influence coefficient of temperature-speed change stored in the database, is the average relative humidity inside the cabin within the set area of a certain lithium-ion power battery, is the average change range of the cabin air pressure within the set area of a certain lithium-ion power battery, is the interaction influence coefficient of environmental change stored in the database, is the natural constant.

[0013] Further, the specific steps to determine whether there is a lithium-ion power battery in the operating group that reaches the rotation rest condition are as follows: Obtain the preset rotation rest threshold and compare and analyze it with the rotation rest priority index of each lithium-ion power battery in the operating group; regard the lithium-ion power battery in the operating group with a rotation rest priority index higher than the preset rotation rest threshold as reaching the rotation rest condition.

[0014] Further, the specific steps to determine the replacement battery from the standby group are as follows: Obtain the replacement status data of each lithium-ion power battery in the standby group and analyze the replacement priority index of each lithium-ion power battery; compare and analyze the replacement priority index of each lithium-ion power battery and select the lithium-ion power battery with the largest replacement priority index in the standby group as the replacement battery.

[0015] Further, the replacement status data includes the maximum pressure difference between battery cells, the control response duration, the internal thermal balance deviation, and the communication signal quality.

[0016] Further, the specific steps to analyze the replacement priority index of each lithium-ion power battery are as follows: Obtain the replacement status calibration data of each lithium-ion power battery, and the replacement status calibration data includes the calibrated pressure difference between battery cells, the calibrated control response duration, the calibrated internal thermal balance deviation, and the calibrated communication signal quality; comprehensively analyze the replacement status data of each lithium-ion power battery in combination with the corresponding replacement status calibration data of the lithium-ion power battery to obtain the replacement priority index of each lithium-ion power battery.

[0017] The present invention has the following beneficial effects: (1) The topology and control method for the rotation balance of lithium-ion power batteries for electric boats obtains the basic structure information of multiple lithium-ion power batteries in the electric boat, establishes a battery node list and conducts compatibility analysis, thereby constructing a topology structure mapping table with the recognition ability of the controller. This mapping structure not only clarifies the connection attributes and scheduling conditions of each battery, but also lays a clear physical and logical foundation for the dynamic configuration of the operating group and the standby group, avoiding operation risks caused by structural incompatibility. At the same time, combined with the operation fitness score threshold, batteries in good condition are configured as the operating group, and batteries in weaker condition are transferred to the standby group, realizing the decentralized rotation scheduling of the operating load and the dynamic management of healthy operation. Compared with the traditional rotation method that lacks a clear grouping logic and the switching mechanism depends on fixed rules, this method greatly improves the topology configuration efficiency and operation stability of the battery system in complex navigation scenarios, helps reduce the failure probability caused by over-operation of the battery, and extends the life cycle of the entire system.

[0018] (2) The topology and control method for the rotation balance of lithium-ion power batteries for electric boats constructs a rotation priority index for the batteries in the operating group based on the time series characteristics of the operating state. This index not only considers the average change range of the supply current and voltage, but also introduces environmental and structural response parameters such as the temperature rise rate, vibration acceleration, cabin humidity and air pressure change, comprehensively reflecting the stability and load condition of the battery in the current operating cycle. In addition, the rotation priority index forms an evaluation function by coupling the current change influence coefficient, the temperature change influence coefficient and the environmental interaction influence coefficient, making the weight relationship of various physical change quantities adjustable and the output result more interpretable. Compared with the existing technology that only uses SOC, voltage or temperature as the single-point judgment basis, this method can identify potential high-risk batteries in advance and rotate them in time, effectively avoiding overheating, imbalance or communication failures caused by continuous high-load operation, and significantly improving the intelligent perception ability and forward-looking regulation level of the battery system during dynamic operation.

[0019] (3) The rotation rest balance topology and control method for the lithium-ion power battery of electric boats constructs a replacement priority index calculation model for candidate batteries based on the replacement state data. By collecting the maximum voltage difference of single battery cells, control response duration, internal thermal balance deviation, and communication signal quality in real time, it comprehensively evaluates whether the candidate batteries have good access adaptability. At the same time, combined with the reference thresholds and balance coefficients recorded in the database for a long time, normalization comparison and exponential operation are performed on the above parameters to ensure that the replacement priority index not only reflects the current state but also considers its relative deviation from the ideal reference value. During the replacement selection process, the battery with the most suitable access conditions can be automatically selected, avoiding problems such as system oscillation, voltage fluctuation, or command response failure caused by the connection of batteries in poor condition. This mechanism significantly enhances the stability and safety of the switching process and is scalable, capable of adapting to different battery structures, communication protocols, and application scenarios. It is an important support logic for realizing the linkage closed-loop control of rotation rest and switching.

[0020] Of course, it is not necessary for any product implementing the present invention to achieve all the above-mentioned advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flowchart of a rotation rest balance topology and control method for the lithium-ion power battery of electric boats according to the present invention.

[0022] Figure 2 It is a flowchart of the specific steps for analyzing the rotation rest priority index of each lithium-ion power battery in the operation group in the rotation rest balance topology and control method for the lithium-ion power battery of electric boats according to the present invention.

[0023] Figure 3 It is a flowchart of the specific steps for determining whether there is a lithium-ion power battery in the operation group that meets the rotation rest condition in the rotation rest balance topology and control method for the lithium-ion power battery of electric boats according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] Please refer to Figure 1, an embodiment of the present invention provides a technical solution: an electric boat lithium-ion power battery rotation balance topology and control method, including the following steps: Based on several lithium-ion power batteries in the electric boat, establish a lithium-ion power battery topology structure, and configure an operation group and a standby group. Both the operation group and the standby group include several lithium-ion power batteries, where the operation group is used for power supply, and the standby group is used for standby access; When the electric boat is running, continuously obtain the operation status time series data of each lithium-ion power battery in the operation group, and analyze the rotation priority index of each lithium-ion power battery in the operation group; For the rotation priority index of each lithium-ion power battery in the operation group, respectively based on the preset rotation rules, determine whether there is a lithium-ion power battery in the operation group that meets the rotation condition, and mark it as a battery to be rotated; If there is a battery to be rotated in the operation group, determine the replacement battery from the standby group and execute the topology switching measure.

[0025] Among them, the specific steps of executing the topology switching measure are as follows: The controller sends a power supply stop pre-instruction to the lithium-ion power battery marked as to be rotated in the operation group, and at the same time sends a pre-access instruction to the selected replacement battery in the standby group to ensure that the two battery channels have a controllable switching buffer in time; Based on the lithium-ion power battery topology structure identified by the system, the controller controls the power output relay corresponding to the battery to be rotated to disconnect, and sets a safety buffer delay during the disconnection process to avoid sudden power supply drop; After the battery to be rotated is disconnected, immediately control the selected replacement battery to connect to the corresponding relay channel, connect it to the operation group topology, and synchronously refresh the operation group structure identifier; After the controller completes the access, detect the current power supply state, voltage stability and communication state of the replacement battery to judge whether the switching is successful; If the detection is abnormal, trigger the emergency switching logic (such as re-selecting the next standby battery); After successful switching, the system marks the original operating battery as "rotation state", and at the same time updates the replacement battery to "operating state", and records the time stamp and data summary of this switching event in the database for subsequent analysis and optimization.

[0026] Specifically, the specific steps of establishing the lithium-ion power battery topology structure are as follows: Obtain the basic structure information of each lithium-ion power battery in the electric boat, and establish a lithium-ion power battery node list (BatteryNodeList). The basic structure information includes battery number (Battery_ID), voltage level (such as 48V / 96V), rated capacity, supported communication protocol (such as CAN, RS485); Conduct a compatibility analysis on each lithium-ion power battery node in the lithium-ion power battery node list, and generate a topology structure mapping table. Specifically: Analyze the structural compatibility of all battery nodes in the BatteryNodeList according to rules such as voltage level, capacity, current specification, and communication protocol to determine its physical or logical connectability, and generate a topology structure table that can be recognized and scheduled by the system controller, including: Voltage level matching and screening: Batteries with the same voltage level are grouped together; Those with inconsistent voltages need to be connected through an intermediate module or isolation control and are not directly connected; Capacity and maximum current balance judgment: Determine which batteries can operate in parallel within the same group without load imbalance; Eliminate combinations that exceed the safe tolerance range (for example, if one battery is rated at 100A and the other is only 60A, they cannot be connected in parallel to supply a large load); Communication protocol adaptation analysis: Batteries with the same communication protocol are grouped into a unified control channel; If RS485 and CAN are mixed, configure a protocol converter or logic bridge; Generate a topology mapping table (controller recognition structure), including but not limited to the following examples: In this implementation plan, by constructing the topology structure of lithium-ion power batteries, the unified identification, grouping, and scheduling control of multiple battery nodes in an electric boat are realized, with high structural flexibility and control accuracy; through the acquisition and compatibility analysis of the basic structure information of the batteries, it is ensured that each node meets the physical and logical connection requirements in terms of voltage level, capacity matching, current carrying capacity, and communication protocol, avoiding the risks of power supply imbalance and communication conflict caused by the parallel connection of incompatible batteries; the finally generated topology mapping table not only facilitates the controller to efficiently identify and manage the operating group and the standby group, but also provides an operable infrastructure for subsequent rotation scheduling and topology switching, significantly improving the operating stability, modular expansion ability, and regulation intelligence level of the system.

[0027] Specifically, the specific steps for configuring the operating group and the standby group are as follows: Obtain the current state data of each lithium-ion power battery in the topology structure mapping table, and analyze the operation fitness score of each lithium-ion power battery. The current state data includes the remaining power state, health state evaluation value, battery case temperature value, temperature rise rate, and continuous power supply duration, and perform unit removal processing; obtain the operation fitness score threshold, and compare and analyze it with the operation fitness score of each lithium-ion power battery respectively. Configure the lithium-ion power batteries with an operation fitness score higher than the operation fitness score threshold as the operating group, and configure the lithium-ion power batteries with an operation fitness score lower than or equal to the operation fitness score threshold as the standby group.

[0028] Among them, the remaining power state refers to the percentage of the remaining power of a certain lithium-ion power battery relative to its rated total capacity, which is used to measure the available energy that the battery can provide currently. It can be obtained by real-time calculation through the coulomb counting method in the battery management system (BMS). Usually, the SOC value ranges from 0% to 100%.

[0029] The health state assessment value refers to the degree of maintenance of the overall performance of the current battery compared to that of a new battery, reflecting the attenuation degree of the battery's service life. It can be obtained by comparing the ratio between the current actual capacity and the initial design capacity.

[0030] The battery case temperature value refers to the current temperature collected in real time by a temperature sensor (such as an NTC thermistor) arranged at the key thermal-sensitive positions on the outer shell of the lithium-ion battery or the battery pack. This temperature is used to evaluate whether the battery is in a safe thermal operation range and indirectly reflects the trend of thermal environment change. The unit is degree Celsius, and it can be read through the CAN or RS485 bus.

[0031] The temperature rise rate represents the rate of temperature change of a certain lithium-ion battery in a recent period of time (such as 1 minute), which is used to judge whether there is a potential risk of thermal accumulation in the battery. It can be obtained by reading the case temperature value every fixed time period (for example, 10 seconds) and through differential calculation.

[0032] The continuous power supply duration refers to the cumulative value of the time that a certain lithium-ion power battery has been continuously in the power supply state since the last switch-on line, reflecting the cumulative degree of its load bearing. It can be recorded by the control system or the internal clock of the BMS, cleared when the battery is switched on each time, and continuously accumulated during the power supply process. Its unit is usually minutes or hours.

[0033] The specific formula for calculating the operation fitness score of a certain lithium-ion power battery is as follows: ; where is the operation fitness score of a certain lithium-ion power battery, is the remaining power state of a certain lithium-ion power battery, is the health state assessment value of a certain lithium-ion power battery, is the battery case temperature value of a certain lithium-ion power battery, is the temperature rise rate of a certain lithium-ion power battery, is the continuous power supply duration of a certain lithium-ion power battery.

[0034] In this implementation, by introducing an operation fitness scoring mechanism, a dynamic operation group and standby group configuration method based on multi-source status data is constructed, significantly improving the rationality and intelligence level of battery scheduling. Compared with the traditional rotation division method that relies solely on the single parameter of SOC, this method comprehensively considers multiple key operation parameters with physical meanings such as remaining power, health status, housing temperature, temperature rise rate, and continuous power supply duration, and can more comprehensively reflect the current operation bearing capacity and risk level of each lithium-ion power battery. By performing unitless processing on all parameters, unified modeling among different physical quantity dimensions is achieved, ensuring the objectivity and comparability of the scoring results. Then, combined with the operation fitness scoring threshold for grouping judgment, the system can dynamically configure batteries with good performance and stable status into the operation group, and schedule batteries with status approaching the risk boundary or high continuous operation load to the standby group for rest, thereby achieving balanced distribution of operation load and overall adjustment of health status, effectively extending the service life of the battery system, and enhancing the safety and stability of the operation process.

[0035] Specifically, the operation status time-series data includes the variation amplitude of the supply current, the variation amplitude of the voltage, the temperature rise rate, the vertical vibration acceleration at several time points, as well as the relative humidity inside the cabin and the variation amplitude of the cabin air pressure within a set area.

[0036] Among them, the variation amplitude of the supply current refers to the degree of difference between the supply current values of the lithium-ion power battery. The current difference is calculated between adjacent time points to obtain the variation amplitude, and the unit of this value is ampere. .

[0037] The variation amplitude of the voltage reflects the fluctuation range of the battery terminal voltage during a certain period of time. By collecting the battery voltage value sequence at adjacent time points, for example, once per minute, and calculating their difference, the variation amplitude of the voltage is obtained. The data is provided by the voltage sampling module in the battery management system, and the unit is volt. .

[0038] The temperature rise rate represents the heating rate of the battery housing or interior. It can be obtained by reading the temperature values at adjacent time points (acquired by a thermistor / temperature sensor), calculating the difference between adjacent temperatures and dividing it by the time interval to obtain the temperature rise rate, and the unit is degrees Celsius per minute (℃ / min).

[0039] The vertical vibration acceleration refers to the vibration intensity that the battery receives in the vertical direction (Z-axis), reflecting whether the installation position where it is located is affected by vibrations or impacts from the hull. It can be collected by a three-axis IMU (inertial measurement unit) installed on the battery compartment or the structural base, and the acceleration value in the Z-axis direction is extracted, and the unit is meters per second squared (m / s²).

[0040] The relative humidity inside the cabin reflects the humidity condition of the air in the area where the battery is located. It can be collected by a humidity sensor (such as a digital temperature and humidity module) installed inside the cabin, and the unit is percentage (%).

[0041] The change range of the air pressure inside the cabin represents the fluctuation degree of the air pressure in the set area. It can obtain the air pressure values at adjacent time points through a pressure sensor (such as a barometer module) installed inside the battery cabin, and calculate the difference, which is the change range, and the unit is hectopascal (hPa).

[0042] As Figure 2 shown, the specific steps to analyze the rest priority index of each lithium-ion power battery in the operation group are as follows: Read the operation status time-series data of each lithium-ion power battery in the operation group, and analyze the operation status time-series feature set of each lithium-ion power battery in the operation group. The operation status time-series feature set includes the average change range of the supply current, the average change range of the voltage, the average temperature rise speed, the average vertical vibration acceleration, and the average relative humidity inside the cabin and the average change range of the air pressure inside the cabin in the set area, and perform unit removal processing; comprehensively analyze the operation status time-series feature set of each lithium-ion power battery in the operation group after unit removal processing to obtain the rest priority index of each lithium-ion power battery in the operation group.

[0043] The specific formula for calculating the rest priority index of a certain lithium-ion power battery in the operation group is as follows: ; where is the rest priority index of a certain lithium-ion power battery, is the average change range of the supply current of a certain lithium-ion power battery, is the current change influence coefficient stored in the database, is the average change range of the voltage of a certain lithium-ion power battery, is the average temperature rise speed of a certain lithium-ion power battery, is the average vertical vibration acceleration of a certain lithium-ion power battery, is the temperature speed change influence coefficient stored in the database, is the average relative humidity inside the cabin of a certain lithium-ion power battery in the set area, is the average change range of the air pressure inside the cabin of a certain lithium-ion power battery in the set area, is the environmental change interaction influence coefficient stored in the database, is the natural constant, and its value is 2.71 in this embodiment.

[0044] It should be explained that the current change influence coefficient stored in the database, the temperature speed change influence coefficient , and the environmental change interaction influence coefficient The specific acquisition steps are as follows: First, It is obtained by regression analysis of the correlation between the average change amplitude of the supply current and the actual battery rotation rest demand frequency in multiple operating cycles, reflecting the sensitivity of current fluctuations to rotation rest triggering; Second, Based on the correlation between the historical temperature rise speed sequence and the actual system performance decay rate, it is obtained by linear fitting, and is used to measure the amplification effect of temperature rise speed changes on battery state fluctuations; Finally, It is the coupling influence weight coefficient extracted by multivariate collaborative regression through the analysis of the interaction between the coupled fluctuation characteristics of cabin air pressure and humidity and the rotation rest records in the set area, and is used to express the non-linear influence degree of environmental disturbances on rotation rest decisions under complex interaction conditions.

[0045] In this implementation plan, by constructing a calculation method for the rotation rest priority index based on the time-series data of the operating state, the dynamic evaluation of the battery operating state and the intelligent upgrade of rotation rest determination are realized. Compared with the traditional method that only relies on static parameters or single state indicators, this method introduces the time-series feature means of supply current, voltage, temperature rise speed, vibration acceleration, humidity and air pressure, which can more comprehensively reflect the current load capacity, thermal stability and environmental adaptability of the battery. At the same time, through the current change influence coefficient, temperature rise speed change influence coefficient and environmental change interaction influence coefficient stored in the database, the sensitivity weight coupling between multi-dimensional parameters is realized, so that the index calculation result has adjustability and trend prediction ability. This method not only improves the accuracy and forward-looking of rotation rest judgment, but also significantly enhances the risk identification and adaptive regulation ability of the system in complex offshore operating environments, providing a safer, more stable and more efficient support mechanism for the operation of the battery pack.

[0046] Specifically, as Figure 3 shown, the specific steps to determine whether there is a lithium-ion power battery in the operating group that reaches the rotation rest condition are as follows: Obtain the preset rotation rest threshold, and compare and analyze it with the rotation rest priority index of each lithium-ion power battery in the operating group; Regard the lithium-ion power battery in the operating group whose rotation rest priority index is higher than the preset rotation rest threshold as reaching the rotation rest condition.

[0047] In this implementation plan, by setting the rotation rest threshold and comparing and analyzing the rotation rest priority index of each battery in the operating group, the quantification, automation and logical controllability of the rotation rest judgment process are realized. Compared with the traditional method that relies on manual experience or single index determination, this method is based on the index-based scoring result and combines the unified set threshold standard, which can accurately identify the battery nodes with large load pressure, poor environmental adaptability or abnormal operation trend under the current state, and automatically mark them as objects to be rotated. This not only significantly improves the intelligent decision-making ability of the battery management system, but also helps to reduce the risk of overloading the battery, extend the overall service life, and improve the safety and stability of system operation.

[0048] Specifically, the specific steps to determine the replacement battery from the candidate group are as follows: Obtain the replacement status data of each lithium-ion power battery in the candidate group, and analyze the replacement priority index of each lithium-ion power battery; Compare and analyze the replacement priority indices of each lithium-ion power battery, and select the lithium-ion power battery with the largest replacement priority index in the candidate group as the replacement battery.

[0049] The replacement status data includes the maximum voltage difference between battery cells, the control response duration, the internal thermal balance deviation, and the communication signal quality.

[0050] Among them, the maximum voltage difference between battery cells refers to the largest one among the voltage differences between all series-connected single cells inside a certain lithium-ion power battery, which reflects whether the voltages of the battery cells are consistent and whether the balance state is good. It can be collected in real time by a multi-channel voltage sampling module inside the battery pack. By reading the voltage values of each single cell one by one, the difference between the maximum value and the minimum value is calculated, and the unit is volt (V).

[0051] The control response duration refers to the time delay experienced by the battery management unit (BMU) to make an effective response after the controller sends a control command (such as connection, status reading, preparatory access, etc.) to the lithium-ion power battery, which reflects its current real-time response ability of the communication and control channels. It can be recorded by the system controller as the difference between the sending time of the communication command frame and the receiving time of the response, and the unit is second (s) or millisecond (ms).

[0052] The internal thermal balance deviation refers to the largest difference between the current temperature values collected by temperature sensors arranged at multiple positions inside a certain battery pack, which is used to measure whether the current thermal distribution of the battery is uniform. It can be obtained by reading the real-time temperature values of multiple thermosensitive points (such as arranged at the battery core, housing, heat sink, etc.) and calculating the difference between the maximum value and the minimum value, and the unit is degree Celsius (℃). The larger the deviation, the greater the risk that the battery may have local overheating or poor heat dissipation.

[0053] The communication signal quality reflects the stability of the current communication link between a certain battery node and the controller, and can be measured by indicators such as RSSI (Received Signal Strength), frame error rate, or signal-to-noise ratio (SNR). It can be obtained in real time by a communication interface module (such as CAN, RS485, wireless module). The RSSI value (unit: dBm) can be read by using the signal strength register provided in the communication protocol stack, or the communication packet loss rate or response delay within a certain period of time can be statistically analyzed as a supplementary reference for the signal quality.

[0054] The specific steps for analyzing the replacement priority index of each lithium-ion power battery are as follows: Obtain the replacement status determination data of each lithium-ion power battery, where the replacement status determination data includes the cell monomer determination pressure difference, the control response determination duration, the internal thermal balance determination deviation, and the communication signal determination quality; comprehensively analyze the replacement status data of each lithium-ion power battery in combination with the corresponding replacement status determination data of the lithium-ion power battery to obtain the replacement priority index of each lithium-ion power battery.

[0055] Among them, the cell monomer determination pressure difference refers to the maximum allowable deviation threshold of the cell voltage used as the target standard reference value in the replacement determination process, which is used to evaluate whether the current cell voltage distribution of a certain battery is in a state where it can be safely connected in parallel. It can be set according to the typical pressure difference statistics results of the historical online successful batteries in the operation experience library. For example, it is obtained by analyzing the 90% confidence interval of the cell pressure difference in hundreds of successful switching records and stored in the database, with the unit of volt (V).

[0056] The control response determination duration is the reference time threshold for evaluating whether the control response of the standby battery meets the standard, which represents the maximum allowable time required for the system to expect the battery node to complete the response after receiving the controller instruction. It can be obtained by the system's statistics of normal response samples in the initial operation stage or training stage, with the unit of millisecond (ms) or second (s). Usually, the average value plus one standard deviation of the normal response distribution of each battery is taken to ensure stability.

[0057] The internal thermal balance determination deviation represents the preset reference standard value of the system for the thermal distribution balance of the battery, which is used to judge whether the current thermal unevenness degree of the standby battery is within the allowable range. It can be extracted from multiple historical datasets and statistically modeled based on the distribution law of the internal temperature difference of the battery (the maximum - minimum difference of the temperature sensors arranged at multiple points), with the unit of degree Celsius (℃).

[0058] The communication signal determination quality is the reference threshold for judging the communication reliability of the standby battery, such as the lowest acceptable received signal strength (RSSI) or the maximum allowable frame loss rate. It can be obtained by the system's statistics under normal communication conditions, and the unit can be dBm (RSSI) or % (packet loss rate). Its value usually takes the lower limit of the average level of the communication signal quality in the normal operation state, which is used to compare whether the current communication state of the standby battery meets the standard.

[0059] Among them, the specific formula for calculating the replacement priority index of a certain lithium-ion power battery is as follows: ; where is the replacement priority index of a certain lithium-ion power battery, is the maximum pressure difference of the cell monomers of a certain lithium-ion power battery, is the cell monomer determination pressure difference of a certain lithium-ion power battery, is the differential pressure equilibrium coefficient stored in the database, is the internal thermal balance deviation of a certain lithium-ion power battery, is the internal thermal balance calibration deviation of a certain lithium-ion power battery, is the temperature difference equilibrium coefficient stored in the database, is the natural constant, and its value is 2.71 in this embodiment, is the control response duration of a certain lithium-ion power battery, is the control response calibration duration of a certain lithium-ion power battery, is the response rate equilibrium coefficient stored in the database, is the communication signal quality of a certain lithium-ion power battery, is the communication signal calibration quality of a certain lithium-ion power battery, is the communication quality equilibrium coefficient stored in the database.

[0060] It should be noted that the differential pressure equilibrium coefficient stored in the database , the temperature difference equilibrium coefficient , the response rate equilibrium coefficient , the communication quality equilibrium coefficient The specific acquisition steps are as follows: By statistically analyzing the correlation between the maximum differential pressure of each cell monomer and the stability after actual online operation, extract the influence weight of the differential pressure control ability on the substitution effect; Based on the comparison relationship between the multi-point temperature difference inside the battery pack and the operating thermal stability, fit the sensitivity coefficient of temperature equilibrium to the thermal performance maintenance ability; Extract from the regression relationship between the battery control response time and the system command execution efficiency after online operation, and measure the influence degree of control delay on response sensitivity; Obtained through the correlation model between the communication signal quality (such as RSSI or frame loss rate) and the online operation stability, reflecting the influence of communication reliability on the system scheduling accuracy.

[0061] In this implementation scheme, by constructing a substitute preference index model, a multi-dimensional quantitative evaluation of the substitution adaptability of each lithium-ion power battery in the standby group is realized, significantly improving the accuracy of substitute battery screening and the stability of access. Compared with the traditional method of selecting standby batteries that only relies on a single state parameter, this scheme comprehensively considers four key instantaneous physical parameters: the cell voltage difference, the control response duration, the thermal distribution uniformity, and the communication quality. It also introduces the calibration threshold and influence weight coefficient obtained from long-term statistics in the database, constructs a normalization processing and coupling operation mechanism, so as to obtain a comparable substitute preference index. Through a unified index scoring framework, the system can effectively exclude standby batteries with excessive voltage difference, serious thermal deviation, slow response, or unreliable communication, and preferentially select nodes with stable status, fast control, good thermal characteristics, and clear communication to access the operation group, maximizing the avoidance of problems such as switching failures, mis-access, or uneven power supply, significantly enhancing the reliability, controllability, and security of the battery scheduling strategy. This mechanism also has good scalability, can adapt to different control strategies and device structures, and supports real-time update and intelligent optimization during operation.

[0062] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0063] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

1. A lithium-ion power battery rotation balance topology and control method for electric ships, characterized in that: The following steps are involved: Based on a plurality of lithium-ion power batteries in the electric ship, a lithium-ion power battery topology structure is established, and an operating group and a standby group are configured, wherein the operating group and the standby group both include a plurality of lithium-ion power batteries; When the electric boat is running, the operating status time series data of each lithium-ion power battery in the operating group is continuously obtained, and the rotation priority index of each lithium-ion power battery in the operating group is analyzed; For the rotation priority index of each lithium-ion power battery in the operation group, based on the preset rotation rules, it is determined whether there is a lithium-ion power battery in the operation group that meets the rotation condition, and it is marked as a battery to be rotated; If there are batteries to be taken off duty in the operating group, a replacement battery is determined from the standby group and topology switching measures are performed.

2. The electric marine lithium-ion power battery rotation balance topology and control method according to claim 1 is characterized in that: The specific steps to establish the topology of lithium-ion power batteries are as follows: Obtain the infrastructure information of each lithium-ion power battery in the electric ship and establish a lithium-ion power battery node list, wherein the infrastructure information includes battery number, voltage level, rated capacity, and supported communication protocol; A compatibility analysis is performed on each lithium-ion power battery node in the lithium-ion power battery node list, and a topology structure mapping table is generated.

3. The electric marine lithium-ion power battery rotation balance topology and control method according to claim 2 is characterized in that: The specific steps to configure the running group and the standby group are as follows: Obtaining the current state data of each lithium-ion power battery in the topology structure mapping table, and analyzing the operation fitness score of each lithium-ion power battery, the current state data including the remaining power state, health status assessment value, battery shell temperature value, temperature rise rate, and continuous power supply time; An operation fitness score threshold is obtained, and compared with the operation fitness score of each lithium-ion power battery for analysis, and lithium-ion power batteries with operation fitness scores higher than the operation fitness score threshold are configured as an operation group, and lithium-ion power batteries with operation fitness scores lower than or equal to the operation fitness score threshold are configured as a candidate group.

4. The electric marine lithium-ion power battery rotation balance topology and control method according to claim 1 is characterized in that: The operating status time series data includes the supply current change amplitude, voltage change amplitude, temperature rise rate, vertical vibration acceleration, and cabin relative humidity and cabin air pressure change amplitude within a set area at several time points.

5. The electric marine lithium-ion power battery rotation balance topology and control method according to claim 4 is characterized in that: The specific steps for analyzing the rotation priority index of each lithium-ion power battery in the operation group are as follows: Read the operating state time series data of each lithium-ion power battery in the operating group, and analyze the operating state time series feature set of each lithium-ion power battery in the operating group, wherein the operating state time series feature set includes the average change amplitude of the power supply current, the average change amplitude of the voltage, the average temperature rise rate, the average vertical vibration acceleration, and the average relative humidity in the cabin and the average change amplitude of the air pressure in the cabin within the set area; The operating state time series feature set of each lithium-ion power battery in the operating group is comprehensively analyzed to obtain the rotation priority index of each lithium-ion power battery in the operating group.

6. The electric marine lithium-ion power battery rotation balance topology and control method according to claim 5 is characterized in that: The specific formula for calculating the rotation priority index of a lithium-ion power battery in the operation group is as follows: ; in, They are the rotation priority index of a lithium-ion power battery, the average change range of the power supply current, the average change range of the voltage, the average temperature rise rate, the average vertical vibration acceleration, the average relative humidity in the cabin within the set area, and the average change range of the cabin air pressure in the set area. They are the current change influence coefficient, temperature change influence coefficient, and environment change interaction influence coefficient stored in the database. is a natural constant.

7. The electric marine lithium-ion power battery rotation balance topology and control method according to claim 1 is characterized in that: The specific steps to determine whether there are lithium-ion power batteries in the operating group that meet the rotation rest conditions are as follows: Obtain the preset rotation threshold value, and compare and analyze it with the rotation priority index of each lithium-ion power battery in the operation group; The lithium-ion power batteries in the operating group whose rotation priority index is higher than the preset rotation threshold are deemed to have met the rotation conditions.

8. The electric marine lithium-ion power battery rotation balance topology and control method according to claim 1 is characterized in that: The specific steps to determine the replacement battery from the candidate group are as follows: Obtaining the substitute status data of each lithium-ion power battery in the candidate group, and analyzing the substitute priority index of each lithium-ion power battery; A comparative analysis is performed on the substitute priority index of each lithium-ion power battery, and the lithium-ion power battery with the largest substitute priority index in the candidate group is selected as the substitute battery.

9. The electric marine lithium-ion power battery rotation balance topology and control method according to claim 8, characterized in that: The substitute status data includes the maximum voltage difference of the battery cell, the control response time, the internal thermal balance deviation, and the communication signal quality.

10. The electric marine lithium-ion power battery rotation balance topology and control method according to claim 8, characterized in that: The specific steps for analyzing the replacement priority index of each lithium-ion power battery are as follows: Acquire the backup state parameter data of each lithium-ion power battery, wherein the backup state parameter data includes the battery cell single body parameter pressure difference, control response parameter duration, internal thermal balance parameter deviation, and communication signal parameter quality; The replacement status data of each lithium-ion power battery is combined with the replacement status parameter data of the corresponding lithium-ion power battery for comprehensive analysis to obtain the replacement priority index of each lithium-ion power battery.

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