Emergency fault processing and battery system reconstruction method for ship lithium power battery system

Abstract

The invention discloses an emergency fault processing and battery system reconstruction method for a ship lithium power battery system, and relates to the technical field of ship power lithium batteries. When the main system and the standby system break down, power output is quickly recovered by cutting off the faulty battery pack or battery cluster and reconstructing the system, and safe sailing of the ship is ensured. According to the technical scheme, a normally open switch K1 (main path) is connected in series in each battery pack, a K2 (standby path) is connected in parallel in each battery pack, and the K1 is switched on and the K2 is switched off normally; and the K1 is cut off and the K2 is closed to isolate the fault packet in fault. The reconstruction strategy comprises a battery pack cutting-out method (synchronously cutting off the same number of battery packs to keep voltage balance), a battery cluster cutting-out method (cutting off the whole cluster) and main and standby hybrid reconstruction. A redundant battery pack is reserved in the system, and dual-channel data transmission is adopted to ensure fault monitoring. After transformation, the battery system realizes fault isolation and power recovery through real-time monitoring and intelligent switching.

Description

Technical Field

[0001] The present invention relates to the technical field of marine power lithium batteries, and specifically to a method for emergency fault handling and battery system reconstruction of a marine lithium battery power system. Background Art

[0002] At present, the marine power lithium battery system has extremely high requirements for safety and reliability. During navigation, the ship must maintain sufficient power output to control the course and speed. The failure of any power system may cause the ship to lose control, leading to collisions or capsizing accidents. Currently, common marine lithium battery systems mainly consist of the following parts: Battery pack: including a battery monitoring unit (BMU), an independent battery temperature control unit (ITMU), and battery modules; Battery cluster management unit: composed of a battery management control unit (BCU), an independent temperature control unit (ITCU), and a high-voltage control unit, responsible for monitoring and protecting the entire battery group; Battery array management unit: composed of a BAU and an ITAU, responsible for overall data collection, fault management, and safety protection of the battery system; Energy management system (EMS): mainly responsible for data acquisition, energy scheduling, optimization control, etc. Currently, marine power lithium battery systems usually adopt the main and backup power system mode. When the main system fails, the backup system takes over the power output; however, in extreme cases, if both the main and backup systems fail, the minimum power requirements of the ship cannot be met, and traditional fault handling and reconstruction solutions often rely on complex circuit structures and high costs, making it difficult to be popularized and applied in large-scale systems. Therefore, a method with low cost, simple structure, rapid response, and capable of realizing online fault diagnosis and system reconstruction is needed to improve the safety and reliability of the marine power lithium battery system. Summary of the Invention

[0003] To overcome the defects of the above-mentioned prior art, the present invention provides the following technical solution: A method for emergency fault handling and battery system reconstruction of a marine lithium battery power system, including the following steps: A normally open battery switch unit K1 is connected in series at the total positive terminal of each battery pack, and a normally open battery switch unit K2 is connected in parallel between the total positive and negative terminals of the battery pack; during normal operation, the battery system controls K1 in the battery pack to close, so that the battery pack remains connected; when a fault (such as too high temperature, overcharging, over-discharging, or cell failure, etc.) occurs in the battery pack, the battery system issues an instruction to the faulty battery pack to disconnect K1 and close K2, so as to cut out the faulty battery pack from the battery system; based on the data of each battery pack collected in real time, the EMS or the corresponding control unit calculates the parameters for reconstructing the entire battery system after the fault is removed, and selects a battery pack cutting method, a battery cluster cutting method, or a mixed reconstruction scheme thereof according to meeting the minimum power requirements of the ship, so as to realize the recombination and parameter setting of the remaining available battery packs.

[0004] Preferably, the faulty battery pack cut-out processing scheme includes: a battery pack cut-out method: for a battery cluster in which a single or partial battery pack failure is detected, the faulty battery cluster cuts the faulty battery pack out of the battery system, and then each battery cluster in the battery array cuts out a number of battery packs corresponding to the faulty battery cluster, and then adjusts the parameters of the remaining battery packs to achieve voltage balance of the entire battery array; a battery cluster cut-out method: for a battery cluster with serious failure, all battery packs in the battery cluster are cut out as a whole by disconnecting the control unit (including the battery switch unit KM1 in the battery cluster management unit) to maintain the voltage platform of the entire battery system; a hybrid reconstruction scheme: when the minimum output power requirement cannot be met by reconstructing the main system or the backup system alone, the main and backup systems are reconstructed by using the battery pack cut-out method and the battery cluster cut-out method at the same time according to certain rules, and the scheme with the best output parameters after reconstruction is selected.

[0005] Preferably, a redundant design is also included in each battery pack, that is, 1 to 2 redundant battery packs are reserved during normal operation, and when a battery pack fails and is cut out, it is automatically supplemented by the redundant battery pack to avoid a drop in output power.

[0006] Preferably, the following steps are also included: S1. Use BMU to monitor the voltage, current and temperature information of each battery cell, and use ITMU to monitor abnormal temperature of battery pack; S2. Use BCU, ITCU and BAU to aggregate data, determine faults and calculate parameters of each battery pack, battery cluster and battery array; S3. EMS collects and processes the collected power demand data, and calculates the optimal reconstruction plan based on the current power demand of the ship and the remaining energy distribution of the battery; S4. After the reconstruction plan is determined, the corresponding battery pack or battery cluster is cut out by controlling the status of its K1, K2 and KM1 (or the corresponding switch unit) to execute the operation of cutting out the faulty battery pack or faulty battery cluster.

[0007] Preferably, when both the main power battery system and the backup power battery system fail, the output is first switched to the backup system, and then the failed system is reconstructed and restored online, and can be automatically switched back to the main system after the main system is restored.

[0008] Preferably, the battery system includes multiple battery arrays, each battery array is composed of multiple battery clusters, each battery cluster is composed of multiple battery packs, and the management units at each level are: battery pack management unit (BMU, ITMU), battery cluster management unit (BCU, ITCU and high-voltage control unit), battery array management unit (BAU and ITAU), and energy management system (EMS).

[0009] Preferably, the control command adopts a dual-channel data transmission mechanism. One route is transmitted from the BMU to the BCU and then to the BAU, and the other route is transmitted from the ITMU to the ITCU, and then from the ITCU to the superior ITAU and BAU, ensuring the redundancy and real-time of the fault signal transmission.

[0010] Preferably, the calculation logic of the battery system reconstruction constitutes a reconstruction algorithm process according to the ship's power demand and the remaining energy of each battery pack. This process includes all steps of data acquisition, fault judgment, scheme evaluation, scheme selection, and reconstruction execution, and obtains optimized output parameters through real-time calculation.

[0011] Preferably, both the normally open battery switch units K1 and K2 are closed in the preset state, and after being triggered by a fault signal, they perform opening or closing operations according to the preset logic, so as to isolate the faulty battery pack from the system.

[0012] Preferably, it is applicable to ship power lithium battery systems and other energy storage systems with a main-backup architecture. It has the advantages of simplified structure, low cost, fast response, and high reliability.

[0013] The present invention has the following beneficial effects compared with the prior art: (1) The system safety is greatly improved: By adding a simple and effective switch unit to quickly cut out the faulty battery pack, even when both the main and backup systems fail, the power output can be restored through online reconstruction to avoid the ship from getting out of control; (2) Low cost and simple implementation: Only two normally open battery switch units are added to the existing battery packs, and online reconstruction is realized through software algorithms, without complex circuit modifications, reducing the overall system cost; (3) Fast reconstruction response speed: Relying on data acquisition and dual-channel fault detection mechanisms, the system parameters can be quickly reconstructed after a fault occurs to ensure the minimum power demand of the ship; (4) Reasonable system redundancy design: Redundant battery packs are reserved to automatically operate after the fault is removed, effectively avoiding the decrease in output power and meeting the application requirements of large-scale ship power lithium battery systems; (5) Wide application range: In addition to ship power systems, its control strategy and reconstruction method are also applicable to the safety control and online reconstruction of other backup battery systems. Description of the Drawings

[0014] Figure 1 It is the topology diagram of the original ship power battery system.

[0015] Figure 2 is Figure 1 the enlarged view of the main power battery system in

[0016] Figure 3 is Figure 1 the enlarged view of the backup power battery system in

[0017] Figure 4This is the topology diagram of the ship power battery system for the invention patent.

[0018] Figure 5 It is Figure 4 the enlarged diagram of the main power battery system in

[0019] Figure 6 It is Figure 4 the enlarged diagram of the backup power battery system in

[0020] Figure 7 This is the diagram of the battery pack architecture change of the invention, as well as the usage status and cut-out status of the battery pack.

[0021] Figure 8 This is the diagram of the usage status and cut-out status of the entire battery cluster of the invention.

[0022] Figure 9 This is the schematic diagram of the battery system reconstruction when the entire cluster of batteries of the invention is cut out.

[0023] Figure 10 This is the schematic diagram of the battery system reconstruction when a single battery pack of the invention is cut out.

[0024] Figure 11 This is the schematic diagram of the battery system reconstruction when the entire cluster of the main power battery system and the backup power battery system of the invention is cut out.

[0025] Figure 12 It is Figure 11 the enlarged diagram of the main power battery system in

[0026] Figure 13 It is Figure 11 the enlarged diagram of the backup power battery system in

[0027] Figure 14 This is the schematic diagram of the battery system reconstruction when a single battery pack of the main power battery system and the backup power battery system of the invention is cut out.

[0028] Figure 15 It is Figure 14 the enlarged diagram of the main power battery system in

[0029] Figure 16 It is Figure 14 the enlarged diagram of the backup power battery system in

[0030] Figure 17 This is the schematic diagram of the battery system reconstruction when a single battery pack and the entire cluster of batteries of the main power battery system and the backup power battery system of the invention are cut out.

[0031] Figure 18 It is Figure 17 the enlarged diagram of the main power battery system in

[0032] Figure 19For Figure 17 The enlarged view of the backup power battery system in

[0033] Figure 20 This is the flow chart of the reconstruction algorithm for the ship power battery system of the present invention. Specific embodiments

[0034] The following combines the attached Figures 1 - 20 drawings, and further illustrates the technical solutions of the present invention through specific embodiments.

[0035] The present invention provides a method for emergency fault handling and battery system reconstruction of a ship lithium power battery system. This method can, when both the main and backup systems fail, cut out the faulty battery pack or battery cluster, and reconstruct the remaining battery packs to quickly restore the power output of the battery system, thus ensuring the safe navigation of the ship.

[0036] To achieve the above object, the present invention adopts the following technical solutions: Add two independently controlled normally open battery switch units in each battery pack: Connect a normally open switch unit K1 in series at the total positive terminal of the battery pack as the main path for the battery pack to be normally connected to the circuit; Connect a normally open switch unit K2 in parallel between the total positive terminal and the total negative terminal of the battery pack as the backup output path. In the normal operation state, the battery system controls to keep K1 closed and K2 open, so that the battery pack participates in the power output; Fault determination: The BMU monitors the voltage, current, and temperature of each battery cell in real time, and the ITMU independently judges the temperature abnormality. When an abnormality (such as too high temperature, overcharge, over-discharge, battery cell failure, etc.) is detected, the battery system immediately issues an instruction to perform the cut-out operation of the faulty battery pack, that is, disconnect K1 and close K2, so as to isolate the faulty battery pack from the entire battery system; Reconstruction of the battery system: After cutting out the faulty battery pack, the EMS adopts the following two or mixed reconstruction strategies for online reconstruction according to the data of all battery packs and battery clusters collected by the system: Battery pack cut-out method: According to the number of faulty battery packs, synchronously cut out the same number of battery packs as the faulty battery cluster in each battery cluster to ensure that the voltages of all battery clusters in the entire battery array are balanced; Battery cluster cut-out method: For a battery cluster with relatively serious faults, the entire battery cluster is cut out, so that all battery packs in the battery cluster are disconnected. When a single solution cannot meet the minimum power requirement, a mixed reconstruction solution for the main and backup systems is adopted, that is, the main and backup systems are simultaneously adjusted in different cut-out ways, and the solution with the optimal output parameters is selected.

[0037] Redundant Design: To avoid a decrease in the output power of a single system caused by removing a faulty battery pack, one or two redundant battery packs are reserved during the design of the battery pack. They can be automatically put into use during the reconstruction of the battery system to ensure that the overall output power does not decrease.

[0038] Data Transmission and Fault Monitoring: The ship battery system adopts a dual-channel data transmission mechanism. One path is that the BMU transmits fault information to the BCU, and then the BCU aggregates and uploads it to the BAU. The other path is that the ITMU transmits it to the ITCU, and then the ITCU transmits it to the ITAU and BAU to ensure the reliable transmission and timely processing of fault information.

[0039] Original Structure Description: In the original ship power battery system, there is no device in the battery pack that can control the cut-off of the battery power output. The topology diagram of its ship power lithium battery system is as Figure 1 shown. The battery system can be composed of multiple battery arrays. This schematic diagram only shows one battery array for easy understanding, and the processing method for multiple arrays is the same as that for a single array.

[0040] Implementation Method for Battery Pack Transformation: To achieve the purpose of controlling the access or cut-out of the battery pack to the battery system, first, a normally open battery switch unit K1 needs to be connected in series in the total positive line of each battery pack, and then a normally open battery switch unit K2 needs to be connected in parallel between the total positive and total negative poles of the battery pack. As Figure 3 shown, when the battery pack is in use, the battery system controls the battery switch unit K1 to close. At this time, the power output of this battery pack is normal and it is in use. When a battery pack fails and needs to be cut out, the battery system controls the battery switch unit K1 to open and simultaneously controls the battery switch unit K2 to close. At this time, the power output line inside this battery pack has been disconnected, and the power output of other battery packs is output through the switch line of K2. Thus, the cut-out operation of this battery pack is completed, and this battery pack is in the cut-out state. For the battery system, after one or several battery packs in a faulty battery cluster are cut out of the system, in order to maintain the voltage balance of the entire battery system, one or several battery packs corresponding to the faulty battery cluster also need to be cut out in other normal battery clusters to keep the voltage of each battery cluster in this battery array similar, so as to avoid problems such as battery inter-circulation caused by different voltages of each battery cluster. As Figure 6 shown, one battery pack needs to be cut out from each battery cluster to maintain the voltage balance of this battery array.

[0041] The topology diagram of the ship power lithium battery system after the battery pack becomes controllable is as Figure 2 shown; Method for using an entire battery cluster and cutting out an entire battery cluster from a battery system: When the entire battery cluster is in normal use, the battery switch units K1 in all battery packs under this battery cluster are in the closed state, keeping K2 in the open state. At the same time, the battery switch unit KM1 in the battery cluster management unit is closed. In this way, all battery packs in the entire cluster are in the connected and used state. Finally, it is used in parallel with other battery clusters through the battery cluster management unit. As Figure 4 , when the entire battery cluster needs to be cut out of the battery system, the two battery switch units K1 and K2 in all battery packs within this battery cluster are in the open state. At the same time, the battery switch unit KM1 in the battery cluster management unit is also in the open state. At this time, the power output circuits of all battery packs inside the battery cluster are disconnected, and the power output line of this battery cluster management unit is also disconnected from other battery clusters. The entire battery cluster is in the cut-out state. As Figure 4 .

[0042] Method for handling faults of a ship's power battery system and reconstructing the battery system: When the main power system of the ship fails and there is no power output, according to Figure 10 , as can be seen from the flow chart of the ship's power battery system reconstruction algorithm, first, the power output will be switched to the backup power system. If the backup power system also fails at this time, first detect whether the main power system has returned to normal. If it has returned to normal, switch back to the main power system for output. If the main power system has not returned to normal, then perform battery system reconstruction. First, calculate the data of the battery system after reconstruction using the battery pack cut-out method and the battery cluster cut-out method based on the data of non-faulty batteries. Judge whether the parameters of the battery system after reconstruction by these two methods meet the minimum power requirements of the ship's power system. There are multiple situations at this time: A. If both schemes meet the minimum power requirements of the ship's power system, then compare which of the final parameters of the two battery system reconstruction schemes is better.

[0043] a. If the parameters of the battery pack cut-out method are better, then execute the battery pack cut-out method. As Figure 6 , cut out the faulty battery packs and the battery packs that do not meet the requirements in each cluster from the battery system.

[0044] b. If the parameters of the battery cluster cut-out method are better, then execute the battery cut-out method. As Figure 5 , cut out the entire battery cluster with faulty battery packs from the battery system.

[0045] B. When the battery pack cut-out method meets the minimum power requirements of the ship's power system while the battery cluster cut-out method does not meet the minimum power requirements of the ship's power system, directly execute the battery pack cut-out method.

[0046] C. When the battery cluster cut-out method meets the minimum power requirements of the ship's power system while the battery pack cut-out method does not meet the minimum power requirements of the ship's power system, directly execute the battery cluster cut-out method.

[0047] When the battery system parameters of both the battery pack cut-out method and the battery cluster cut-out method cannot meet the minimum power requirement of the ship's power system, the hybrid reconstruction of the main power system and the backup power system is started: A. Reconstruct the entire main power and backup power battery system according to the battery pack cut-out method; as Figure 8 shown, obtain the battery system parameters after reconstruction; B. Reconstruct the entire main power and backup power battery system according to the battery cluster cut-out method; as Figure 7 shown, obtain the battery system parameters after reconstruction; C. Reconstruct the entire battery system using a method that combines the battery pack cut-out method and the battery cluster cut-out method, as Figure 9 shown, obtain the battery system parameters after reconstruction; Select the optimal solution among these three solutions for battery reconstruction. After the battery system reconstruction is completed, the battery system needs to reconfigure the battery system parameters after reconstruction and set the charge and discharge parameters suitable for the current battery system, etc.

[0048] All the drawing examples are one of the battery system reconstruction methods in this patent, and are not limited to this.

Claims

1. A method for emergency fault handling and battery system reconstruction of a ship lithium power battery system, characterized in that: The following methods are included: A normally open battery switch unit K1 is connected in series at the total positive terminal of each battery pack, and a normally open battery switch unit K2 is connected in parallel at the total positive and total negative terminals of the battery pack; During normal operation, the battery system controls K1 in the battery pack to close, so that the battery pack remains connected; When a battery pack fails, the battery system sends a command to the faulty battery pack to disconnect K1 and close K2 to cut the faulty battery pack out of the battery system. Based on the real-time collected data of each battery pack, the EMS or the corresponding control unit calculates the parameters for reconstructing the entire battery system after the fault is removed, and selects the battery pack cut-out method, battery cluster cut-out method or a mixed reconstruction method based on meeting the minimum power requirements of the ship, thereby realizing the recombination and parameter setting of the remaining available battery packs.

2. A method for emergency fault handling and battery system reconstruction of a marine lithium power battery system according to claim 1, characterized in that: The faulty battery pack cut-out processing solution includes: Battery pack cut-out method: For a battery cluster that detects a single or partial battery pack failure, the faulty battery cluster cuts the faulty battery pack out of the battery system. Then, after each battery cluster in the battery array cuts out the number of battery packs corresponding to the faulty battery cluster, the voltage balance of the entire battery array is achieved by adjusting the parameters of the remaining battery packs. Battery cluster cut-out method: For battery clusters with serious faults, all battery packs in the battery cluster are cut out by disconnecting the control unit to maintain the voltage platform stability of the entire battery system; Hybrid reconstruction scheme: When the reconstruction of the main system or backup system alone cannot meet the minimum output power requirement, the main and backup systems are reconstructed by using the battery pack cut-out method and the battery cluster cut-out method at the same time according to certain rules, and the scheme with the best output parameters after reconstruction is selected.

3. A method for emergency fault handling and battery system reconstruction of a marine lithium power battery system according to claim 2, characterized in that: It also includes adding redundancy design to each battery pack, that is, reserving 1 to 2 redundant battery packs during normal operation, and automatically replenishing them when a battery pack fails to be cut off, so as to avoid a drop in output power.

4. A method for emergency fault handling and battery system reconstruction of a ship lithium power battery system according to claim 1, characterized in that: The following steps are also included: S1. Use BMU to monitor the voltage, current and temperature information of each battery cell, and use ITMU to monitor abnormal temperature of the battery pack; S2, through BCU, ITCU and BAU, data of each battery pack, battery cluster and battery array are aggregated, faults are determined and parameters are calculated; S3, EMS collects and processes the collected power demand data, and calculates the optimal reconstruction solution based on the current power demand of the ship and the remaining energy distribution of the battery; S4. After the reconstruction plan is determined, the corresponding battery pack or battery cluster is cut out by controlling the states of K1, K2 and KM1.

5. A method for emergency fault handling and battery system reconstruction of a marine lithium power battery system according to claim 4, characterized in that: When both the main power battery system and the backup power battery system fail, the output will first be switched to the backup system, and then the failed system will be reconstructed and restored online. After the main system is restored, it can automatically switch back to the main system.

6. A method for emergency fault handling and battery system reconstruction of a ship lithium power battery system according to claim 5, characterized in that: The battery system includes multiple battery arrays, each battery array is composed of multiple battery clusters, each battery cluster is composed of multiple battery packs, and the management units at each level are: battery pack management unit, battery cluster management unit, battery array management unit, and energy management system.

7. A method for emergency fault handling and battery system reconstruction of a marine lithium power battery system according to claim 1, characterized in that: The control command adopts a dual-channel data transmission mechanism, one route is transmitted from BMU to BCU, the other route is transmitted from ITMU to ITCU, and then transmitted from ITCU to the upper-level ITAU and BAU, ensuring the redundancy and real-time performance of fault signal transmission.

8. The method for emergency fault handling and battery system reconstruction of a marine lithium power battery system according to claim 1, characterized in that: The calculation logic of the battery system reconstruction constitutes a reconstruction algorithm process according to the ship power demand and the remaining energy of each battery pack. The process includes all the steps of data collection, fault judgment, solution evaluation, solution selection and reconstruction execution, and obtains the optimized output parameters through real-time calculation.

9. A method for emergency fault handling and battery system reconstruction of a marine lithium power battery system according to claim 1, characterized in that: The normally open battery switch units K1 and K2 are both closed in a preset state, and are opened or closed according to a preset logic after being triggered by a fault signal, thereby isolating the faulty battery pack from the system.

10. A method for emergency fault handling and battery system reconstruction of a marine lithium power battery system according to any one of claims 1 to 9, characterized in that: Applicable to ship power lithium battery systems and other energy storage systems with primary and backup architectures.

Images