Battery Management System

Abstract

The present invention provides a battery management system for managing a battery system, wherein the battery system includes multiple battery clusters, each battery cluster includes multiple battery packs, and the battery management system includes: multiple battery cluster management systems, each battery cluster management system is configured to manage a corresponding battery cluster, wherein one battery cluster management system among the multiple battery cluster management systems acts as a main management system to manage other battery clusters, and one or more battery cluster management systems other than the main management system act as alternative main management systems.

Description

Technical Field

[0001] The present invention relates to the technical field of smart grids, and in particular to a battery management system. Background Art

[0002] As a cornerstone in the development of smart grids, microgrids can access a large amount of renewable energy (such as photovoltaics, wind turbines, fuel cells, etc.) in an economical and environmentally friendly manner. Due to the inherent intermittent and random characteristics of wind, solar and other new energy power generation, it will have an adverse impact on the safe and stable operation of the power grid. The development of energy storage technology can improve its operation quality. A reasonable and efficient battery management system plays a vital role in the life of the battery pack and the safety of the entire battery system.

[0003] Microgrids can be connected to the grid or operated in an island to improve power supply reliability. Hierarchical control strategies are widely used in microgrids, that is, the bottom layer adopts a droop control strategy, the second layer adopts automatic power generation control, and the third layer implements economic dispatch. Traditional methods mostly use a centralized control method through a central controller to achieve the third-layer economic dispatch. Since this method is centralized, when the central controller fails, the entire system is prone to collapse, and when the microgrid is expanded, the control structure needs to be readjusted, and the scalability is poor. In addition, the large-scale economic dispatch and the small-scale automatic power generation control cannot be seamlessly integrated, which reduces the operating efficiency of the microgrid.

[0004] In addition, most of the existing battery management systems are directly quoted from the battery management system of electric vehicles. They serve small batteries, have single functions, and poor real-time performance. The large-capacity batteries in the megawatt-class battery system are connected in series, which puts forward more stringent requirements for the consistency management of the battery. After multiple charges and discharges, the performance of the battery cells will be inconsistent, resulting in the deterioration of the overall performance of the battery, affecting the battery life and the accuracy of the battery stack state of charge SOC calculation. This requires the battery management system to not only detect the battery status in real time and upload it to the energy conversion PCS system and the upper-level monitoring system in a timely manner, but also have a reasonable and efficient balancing module to alarm the possible faults of the battery pack and protect the function of the battery itself. Summary of the invention

[0005] The object of the present invention is to provide a battery management system to solve the problem that the battery system of the existing new energy system is prone to crash due to a fault in the battery management system.

[0006] Another object of the present invention is to provide a battery management system to solve the problem of low battery performance caused by low battery system management level in existing new energy systems.

[0007] In order to solve the above technical problems, the present invention provides a battery management system for managing a battery system, wherein the battery system includes N battery clusters, where N is a natural number greater than or equal to 1; wherein each battery cluster includes M battery packs, where M is a natural number greater than or equal to 1; the battery management system includes:

[0008] N battery cluster management systems, each battery cluster management system is configured to manage a corresponding battery cluster, wherein one battery cluster management system among the N battery cluster management systems acts as a master management system to manage the battery cluster and other battery clusters, and one or more battery cluster management systems other than the master management system act as alternate master management systems, and the role of the master management system can be switched between the N battery cluster management systems when operating conditions change.

[0009] Optionally, the battery management system further includes:

[0010] An energy management system is configured to manage the entire battery system by managing a battery cluster management system;

[0011] A plurality of battery measurement units, each battery measurement unit is configured to measure information of a corresponding battery pack and provide the information to a battery cluster management system corresponding to the battery cluster in which the battery measurement unit is located; and

[0012] A power conversion system configured to perform AC / DC inversion between the entire battery system and an external circuit;

[0013] The battery pack information includes voltage, current, temperature, balancing control information and fault information.

[0014] Optionally, in the battery management system, the battery cluster management system, as a core module of the corresponding battery cluster, performs one or more of the following actions:

[0015] The collected information of the battery packs in this cluster;

[0016] According to the information of the battery pack, the cluster summary information is formed, and the cluster summary information is sent to the main management system and / or the energy management system; the cluster summary information includes the battery pack information and / or the cluster management strategy;

[0017] Perform high voltage management, charge and discharge management, environment management, balancing management, fault diagnosis and enabling control of the battery pack of this cluster according to the summary information and / or overall management strategy of this cluster;

[0018] The battery cluster management system performs battery state estimation and balancing control according to the temperature, voltage and / or current of each battery pack in the cluster.

[0019] Optionally, in the battery management system, the battery cluster summary information includes key information and complete information, wherein:

[0020] The key information is sent to the main management system through the inter-cluster bus, and the main management system controls the power access, energy management, power management and fault diagnosis of the entire battery system according to the key information of each battery cluster management system;

[0021] The complete information is sent to the energy management system through the hierarchical bus, and the energy management system summarizes and records the operating data of the entire battery system according to the complete information to perform energy management of the entire battery system;

[0022] The main management system forms an overall management strategy for the battery group based on key information of some / all battery cluster management systems, or the energy management system forms an overall management strategy for the group based on complete information of some / all battery cluster management systems;

[0023] The management of the battery cluster summary information and / or overall management strategy and / or battery system also includes data configuration, remote monitoring, and system upgrades.

[0024] Optionally, in the battery management system, each battery cluster management system is connected to an inter-cluster bus between the battery cluster management systems, and data is exchanged between the battery cluster management systems via the inter-cluster bus;

[0025] The alternative primary management system is configured to act as the primary management system when the primary management system fails or has insufficient capacity;

[0026] Each battery cluster management system transmits the collected battery pack information to the main management system through the inter-cluster bus; the main management system summarizes and processes the key information of the inter-cluster bus.

[0027] Optionally, in the battery management system, the main management system communicates with the energy management system via a first level bus to transmit key information;

[0028] The main management system and the power conversion system communicate via the second-level bus to ensure the normal operation of the high-voltage management of the entire battery system;

[0029] The energy management system and the power conversion system communicate through the third-level bus to meet the dispatching requirements of the station for battery system power or energy management;

[0030] The battery cluster management system other than the main management system communicates with the energy management system via the fourth-level bus to transmit complete information;

[0031] The transmission speed of the first-level bus is higher than the transmission speed of the fourth-level bus.

[0032] Optionally, in the battery management system, each battery measurement unit communicates with the battery cluster management system of the cluster to which it belongs via CAN bus / or daisy chain communication; the communication method is not limited to the above;

[0033] Each battery cluster management system communicates via CAN bus / or Ethercat; not limited to the above communication methods;

[0034] Each battery cluster management system communicates with the energy management system via Ethernet; the communication method is not limited to the above;

[0035] The main management system communicates with the energy management system via RS485 bus / or Ethernet, and the main management system communicates with the power conversion system via CAN bus; the communication methods are not limited to the above;

[0036] The energy management system communicates with the power conversion system via Ethernet.

[0037] Optionally, in the battery management system, each battery cluster management system selects a main management system based on the operating status through a competition rule, wherein the competition rule includes:

[0038] The performance calculation score is obtained by directly comparing the comprehensive weighted values ​​of the CPU load rate and RAM usage rate of each battery cluster management system. The lower the CPU load rate and RAM usage rate, the higher the performance calculation score. The battery cluster management system with the highest performance calculation score is selected as the main management system, or

[0039] Indirectly, by comparing the number of election signals sent by each battery cluster management system in a unit time, the battery cluster management system that sends the most election signals per unit time is selected as the main management system;

[0040] When a battery cluster management system is selected as the main management system, its status remains unchanged during normal operation until a failure or insufficient capacity occurs, then competition will be resumed to achieve decentralized management of the battery system and one main and multiple backups.

[0041] Optionally, in the battery management system, when the main management system detects an alarm or fault in the battery system, it informs the power conversion system of its current abnormal state through the CAN bus, and informs the energy management system of its current abnormal state through the RS485 bus / or Ethernet; the communication methods are not limited to the above.

[0042] When the battery system has power or energy demand, the energy management system implements effective energy management of the battery system based on the status of the entire battery system, including:

[0043] When the battery cluster of the battery system is low on power due to long-term storage, the battery cluster needs to be charged. The main management system sends a charging demand signal to the energy management system. The energy management system sends a charging instruction to the power conversion system based on the operating status of the battery system. The power conversion system charges the battery system on the DC side based on the current status of the main management system.

[0044] Optionally, in the battery management system, the energy management system communicates with the power conversion system via Ethernet. When the site station makes a scheduling demand for the power or energy of the battery system, the power conversion system is designated for scheduling, including:

[0045] At the signal link level: When the station has a frequency regulation or peak regulation demand, the energy management system will issue a dispatch demand instruction to the power conversion system based on the station's demand. The power conversion system responds to the energy management system's demand based on the main management system's current power state and energy state, and feeds back the actual response data to the energy management system.

[0046] At the power line level: the DC power at the energy storage end and the AC power at the grid end are converted into energy through the power conversion system.

[0047] The inventor of the present invention has found through research that the battery management system of the existing battery system includes the following methods:

[0048] For example, a distributed three-layer management system is adopted, including the bottom BMU, the middle BCMS and the top BAMS. Among them, the bottom BMU includes a voltage and temperature measurement module and a charging and discharging equalization module. The middle BCMS is the core of the battery management system, including a voltage and temperature processing module, an equalization control module, a relay control module, an AD acquisition module, and a core parameter calculation module. The top BAMS includes a battery information summary module, a system alarm information processing module, a BAMS+PCS communication module, and a BAMS_upper monitoring system communication module. The three-layer structure of the system uses the CAN2.0B communication protocol to realize information transmission. BAMS communicates with the energy conversion PCS system and the upper monitoring system using the ModbusTCP protocol. This system topology architecture adopts a real three-layer system. The battery management system requires three types of hardware: the battery strategy system BMU, the battery cluster management system BCMS, and the battery pack management unit BAMS. Multiple hardware systems are required, the system space layout complexity increases, the hardware cost increases, and the battery management unit BAMS is unique. There is no communication between the battery cluster management system BCMS. Once the battery management unit BAMS fails, the entire system will shut down, reducing the online operation rate of the system.

[0049] For example, in another system architecture, each inverter interface power supply in the microgrid is assigned an intelligent agent to complete communication and data calculation; based on the N-1 rule, the communication topology between the intelligent agents is designed; the microgrid operating state is identified in a distributed manner; the algorithm is initialized based on the identified microgrid operating state; through data interaction between the intelligent agents, the reference value of the power generation of each power supply is obtained in a distributed manner; the reference value of the power generation is sent to the bottom droop controller to realize the distributed economic automatic power generation control of the microgrid. The essence of this system is a two-layer architecture, which adopts a completely distributed control. Each intelligent agent independently controls its own operating turntable by obtaining the status of other intelligent agents. However, for large-scale energy storage DC systems, the battery system itself is an energy source. In comparison, the system needs to obtain more information about the battery cluster, and the system operation state machine is more. It is not a single or a few variables that can ensure the stable and safe operation of the system. It is difficult to rely entirely on the independent control of each battery cluster controller, which is not completely suitable for new energy battery systems. Therefore, this system architecture is more suitable for power-type systems and not suitable for large-scale new energy battery systems.

[0050] In the existing battery management system, each intelligent agent interacts with other intelligent agents through information exchange, iterates the data from other intelligent agents, obtains the current system status, and then implements a distributed control strategy, so there is no need for a virtual master to control other intelligent agents. The core of the present invention is one master and multiple backups. In addition to information exchange, there is also control of the master over the slaves and the output of information to the outside by the master.

[0051] In the battery management system provided by the present invention, each battery cluster management system manages the corresponding battery cluster, and the energy management system manages the entire battery system by managing all battery cluster management systems, thereby realizing battery management of the battery system. One of the multiple battery cluster management systems is used as the main management system to manage other battery clusters at the same time, and the battery cluster management systems other than the main management system are used as redundancy of the main management system, thereby realizing hot backup of the control system without adding hardware;

[0052] Through the transmission of the inter-cluster bus, the hardware-level communication connection between the battery cluster management system (Rack BMS) and the main management system (BankBMS) is eliminated, the data transmission is more reliable, the system structure is simpler, and the cost is better.

[0053] Each Rack BMS determines the position of Bank BMS through competition to ensure that the Bank BMS system operates in the optimal operating environment. Even if the Bank BMS cannot operate normally due to failure or other reasons, other Rack BMS can still replace the Bank BMS to continue to ensure system operation, which can improve system reliability and increase system online rate.

[0054] The present invention adopts a decentralized architecture to manage the battery system, which can realize one master and multiple backups, and has the following advantages:

[0055] Improve system online rate: Each Rack BMS determines the position of Bank BMS through competition to ensure that the BankBMS system runs in the optimal operating environment. Even if the Bank BMS cannot operate normally due to failures or other reasons, other RackBMS can still replace the Bank BMS to continue to ensure system operation, which can improve system reliability and increase system online rate.

[0056] Control system hot backup: without adding hardware, hot backup of the control system can be achieved;

[0057] The system is simple and the cost is better: the status of the Bank BMS is determined by the competition among the Rack BMSs, which eliminates the hardware entity of the main management system, and then eliminates the hardware-level communication connection between the battery cluster management system (Rack BMS) and the main management system (BankBMS). The data transmission is more reliable, the system structure is simpler, and the cost is better.

[0058] Aiming at the special requirements of the energy storage field for the battery management system, the present invention proposes an energy storage battery management system with high reliability, complete functions, timely and stable communication and relatively complete management system architecture. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 is a schematic diagram of a battery management system in an embodiment of the present invention;

[0060] Figure 2 is a schematic diagram of a battery management system in another embodiment of the present invention;

[0061] Figure 3 is a schematic diagram of a battery management system in another embodiment of the present invention. DETAILED DESCRIPTION

[0062] The present invention will be further described below in conjunction with specific embodiments with reference to the accompanying drawings.

[0063] It should be noted that the components in the figures may be shown exaggeratedly for the sake of illustration and are not necessarily true to scale. In the figures, identical or functionally identical components are provided with the same reference numerals.

[0064] In the present invention, unless otherwise specified, "arranged on...", "arranged above..." and "arranged above..." do not exclude the existence of an intermediate between the two. In addition, "arranged on or above..." merely indicates the relative positional relationship between two components, and in certain cases, such as after reversing the product direction, it can also be converted into "arranged below or below...", and vice versa.

[0065] In the present invention, each embodiment is only intended to illustrate the aspects of the present invention and should not be construed as limiting.

[0066] In the present invention, unless otherwise specified, the quantifiers "a", "an" and "an" do not exclude the presence of a plurality of elements.

[0067] It should also be noted that in the embodiments of the present invention, for the sake of clarity and simplicity, only a portion of the parts or components may be shown, but those of ordinary skill in the art will understand that under the teachings of the present invention, the required parts or components may be added according to the needs of the specific scenario. In addition, unless otherwise specified, the features in different embodiments of the present invention may be combined with each other. For example, a feature in the second embodiment may be used to replace a corresponding or functionally identical or similar feature in the first embodiment, and the resulting embodiment also falls within the disclosure scope or recorded scope of the present application.

[0068] It should also be noted that within the scope of the present invention, the terms "same", "equal", "equal to" and the like do not mean that the values ​​of the two are absolutely equal, but allow a certain reasonable error, that is, the terms also cover "substantially the same", "substantially equal", "substantially equal to". By analogy, in the present invention, the terms "perpendicular to", "parallel to" and the like indicating directions also cover the meanings of "substantially perpendicular to" and "substantially parallel to".

[0069] In addition, the numbering of the steps of the methods of the present invention does not limit the execution order of the method steps. Unless otherwise specified, the method steps can be executed in different orders.

[0070] The battery management system proposed in the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer according to the following description and claims. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0071] The object of the present invention is to provide a battery management system to solve the problem that the battery system of the existing new energy system is prone to crash due to a fault in the battery management system.

[0072] Another object of the present invention is to provide a battery management system to solve the problem of low battery performance caused by low battery system management level in existing new energy systems.

[0073] To achieve the above-mentioned purpose, the present invention provides a battery management system for managing a battery system of a new energy system, wherein the battery system includes multiple battery clusters, each battery cluster includes multiple battery packs, and the battery management system includes: multiple battery cluster management systems, each battery cluster management system is configured to manage its corresponding battery cluster; and an energy management system is configured to manage the entire battery system by managing all the battery cluster management systems; wherein one battery cluster management system among the multiple battery cluster management systems serves as a main management system and manages other battery clusters at the same time; and battery cluster management systems other than the main management system serve as redundancy of the main management system.

[0074] The present invention realizes decentralized management of large-scale new energy battery systems, with one master and multiple backups, and enhances the online rate and robustness of system operation.

[0075] Specifically, the beneficial effects of the present invention include:

[0076] First, hot backup of the control system can be achieved without adding hardware;

[0077] Second, the hardware-level communication connection between the battery cluster management system (Rack BMS) and the main management system (Bank BMS) is eliminated, data transmission is more reliable, the system structure is simpler, and the cost is better;

[0078] Third, each Rack BMS determines the status of Bank BMS through competition to ensure that the Bank BMS system operates in the optimal operating environment. Even if the Bank BMS cannot operate normally due to failures or other reasons, other Rack BMS can still replace the Bank BMS to continue to ensure system operation, which can improve system reliability and increase system online rate.

[0079] The battery management system of the present invention mainly includes the following components:

[0080] Battery Measurement Unit (BMU): responsible for collecting the voltage, temperature and balance control of the battery system;

[0081] Rack Battery Management System (Rack BMS): It is the core module of the entire system, responsible for managing individual battery cell information, high voltage management, charge and discharge management, environment management, balancing management, battery system fault diagnosis, control and other functions;

[0082] Main Management System (Bank Battery Management System, Bank BMS): responsible for summarizing the key information of each RackBMS to control the power access, energy management, power management, fault diagnosis and other functions of the entire system;

[0083] Energy Management System (EMS): responsible for summarizing and recording battery system operation data and performing system energy management;

[0084] Power Conversion System (PCS): responsible for AC / DC conversion.

[0085] In one embodiment of the present invention, the Bank BMS does not have independent physical hardware, but shares a hardware system with the Rack BMS. Each Rack BMS can work as a Bank BMS, and each Rack BMS determines the Bank BMS through competition.

[0086] The systems exchange information through communication, including but not limited to CAN, SPI, RS485, Ethernet, Ethercat, etc. The above systems are not limited to control and management during normal operation, but also have functions such as data configuration, remote monitoring, and system upgrade.

[0087] Among the subsystems of each battery pack, each BMU is connected to a bus, and the collected data is transmitted to the Rack BMS through their shared bus; each battery cluster battery management system Rack BMS also exchanges data through the bus, and the system selected as Bank BMS summarizes and processes the key data of the bus; each Rack BMS can exchange data with the EMS; in addition to communicating with each Rack BMS, the Bank BMS also establishes communication with the EMS and PCS; as an energy management unit, the EMS also needs to communicate with the PCS.

[0088] The subsystem BMU of each battery pack samples the battery temperature and voltage data, and transmits the data to the Rack BMS through a specified communication method; the Rack BMS is the core module of the entire system, which performs high voltage management, charge and discharge management, environmental management, balancing management, battery system fault diagnosis, control and other functions based on the aggregated information of each battery cell (including voltage and temperature); the balancing management part is executed by controlling the BMU through the Rack BMS, and the battery cluster management system estimates the battery state and performs balancing control based on the temperature, voltage and / or current of each battery in the cluster; the Bank BMS controls and manages the entire battery pack based on the information of each battery cluster, including high voltage management, energy management, power management, fault diagnosis and other functions;

[0089] As mentioned above, each Rack BMS determines the Bank BMS through competition. When a Bank BMS is selected, the Bank BMS position will not be repeatedly elected during the normal operation of the system. When the system selected as the Bank BMS fails or has insufficient capacity, the system will re-election, thereby realizing decentralized management of the system, one master and multiple backups, and enhancing the online rate and robustness of the system operation; each Rack BMS can upload data to the EMS, and the EMS will record the data and perform energy management based on the data. The amount of data in this part is relatively large, and the transmission speed requirement is relatively low; the Bank BMS exchanges data with the EMS through a separate channel. This part is critical operating data, and the real-time transmission requirement is relatively high; the Bank BMS will establish real-time communication with the PCS to ensure the normal operation of the high-voltage management of the entire system; communication will also be established between the EMS and the PCS to meet the site's scheduling needs for battery system power or energy management.

[0090] The traditional new energy battery system architecture is represented by a three-layer architecture. The present invention adopts a decentralized architecture to manage the battery system, which can achieve one master and multiple backups, and has the following advantages:

[0091] Improve system online rate: Each Rack BMS determines the position of Bank BMS through competition to ensure that the BankBMS system runs in the optimal operating environment. Even if the Bank BMS cannot operate normally due to failures or other reasons, other RackBMS can still replace the Bank BMS to continue to ensure system operation, which can improve system reliability and increase system online rate.

[0092] Control system hot backup: without adding hardware, hot backup of the control system can be achieved;

[0093] The system is simple and the cost is better: the hardware-level communication connection between the battery cluster management system (Rack BMS) and the main management system (BankBMS) is eliminated, the data transmission is more reliable, the system structure is simpler, and the cost is better.

[0094] In one embodiment of the present invention, Figure 1 As shown, a decentralized battery system battery management system architecture includes the following components: battery sampling unit BMU, battery cluster management system Rack BMS, main management system Bank BMS, energy management system EMS, power conversion system PCS;

[0095] In one embodiment of the present invention, Figure 2 As shown, the communication mode between each system is as follows: each BMU communicates with the Rack BMS through CAN / or daisy chain communication to realize data exchange; each Rack BMS communicates and connects through CAN / or Ethercat, and based on its operating status, determines the status of one of the Rack BMS as the Bank BMS; each Rack BMS is connected to the EMS through Ethernet; the system determined as the Bank BMS establishes communication with the EMS through RS485 / or Ethernet, and communicates with the PCS through CAN; the EMS and PCS establish communication through Ethernet.

[0096] The working principle of the battery management system of the present invention includes: the subsystem BMU of each battery pack samples the battery temperature and voltage data, and transmits the data to the Rack BMS through CAN; the Rack BMS, as the core module of the whole system, performs high voltage management, charge and discharge management, environmental management, balancing management, battery system fault diagnosis, control and other functions according to the summarized information of each battery cell (including voltage and temperature); wherein the balancing management part is executed by the Rack BMS by sending instructions to control the BMU through CAN; the Bank BMS controls and manages the entire battery pack according to the information of each battery cluster, including high voltage management, energy management, power management, fault diagnosis and other functions; as mentioned above, each Rack BMS bus CAN performs data sharing, and then determines the Bank BMS through competition. When a Bank BMS is selected, the Bank BMS position will not be repeatedly elected during the normal operation of the system. When the system selected as the Bank BMS fails or has insufficient capacity, the system will re-election, thereby realizing the decentralized management of the system, one master and multiple backups, and enhancing the online rate and robustness of the system operation; each Rack BMS can upload data to EMS via Ethernet. EMS will record the data and perform energy management based on the data. The amount of data in this part is relatively large and the transmission rate is low, which is defined as the slow layer here. Bank BMS exchanges data with EMS via RS485. This part is key operating data and has relatively high transmission speed requirements, which is defined as the fast layer here. Bank BMS and PCS establish real-time communication through CAN to ensure the normal operation of the high-voltage management of the entire system. When Bank BMS finds that there is an alarm or fault in the system, it will inform PCS through CAN / or Ethernet at the same time, and inform EMS of its current abnormal status through RS485 / or Ethernet. EMS and PCS communicate through Ethernet. When the site proposes a scheduling requirement for the battery system power or energy, it will specify PCS for scheduling. When the battery system has power or energy requirements, EMS will achieve effective energy management of the system based on the status of the entire system.

[0097] In summary, the above embodiments describe in detail different configurations of the battery management system. Of course, the present invention includes but is not limited to the configurations listed in the above embodiments. Any content that is transformed based on the configurations provided in the above embodiments belongs to the scope of protection of the present invention. Those skilled in the art can draw inferences based on the contents of the above embodiments.

[0098] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0099] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A battery management system, characterized in that: It is used to manage a battery system, the battery system includes N battery clusters, N is a natural number greater than or equal to 1; Each battery cluster includes M battery packs, where M is a natural number greater than or equal to 1; The battery management system comprises: N battery cluster management systems, each battery cluster management system is configured to manage a corresponding battery cluster, wherein one of the N battery cluster management systems acts as a main management system to manage the battery cluster and other battery clusters, and one or more battery cluster management systems other than the main management system act as alternative main management systems, and the role of the main management system can be switched between the N battery cluster management systems when the operating conditions change, wherein each battery cluster management system is connected for communication via CAN / or Ethercat, and based on its operating status, determines the status of one of the battery cluster management systems as the main management system, and when the system selected as the main management system fails or has insufficient capacity, the system will re-election; each battery cluster management system is connected to the EMS via Ethernet; the system determined as the main management system establishes communication with the EMS via RS485 / or Ethernet, and establishes communication with the PCS via CAN; communication is established between the EMS and the PCS via Ethernet.

2. The battery management system according to claim 1, characterized in that: Also includes: An energy management system is configured to manage the entire battery system by managing a battery cluster management system; A plurality of battery measurement units, each battery measurement unit is configured to measure information of a corresponding battery pack and provide the information to a battery cluster management system corresponding to the battery cluster; as well as A power conversion system configured to perform AC / DC inversion between the entire battery system and an external circuit; The battery pack information includes voltage, current, temperature, balancing control information and fault information.

3. The battery management system according to claim 2, characterized in that: The battery cluster management system, as the core module of the corresponding battery cluster, performs one or more of the following actions: The collected information of the battery packs in this cluster; According to the information of the battery pack, the cluster summary information is formed, and the cluster summary information is sent to the main management system and / or the energy management system; the cluster summary information includes the battery pack information and / or the cluster management strategy; Perform high voltage management, charge and discharge management, environment management, balancing management, fault diagnosis and enabling control of the battery pack of this cluster according to the summary information and / or overall management strategy of this cluster; The battery cluster management system performs battery state estimation and balancing control according to the temperature, voltage and / or current of each battery pack in the cluster.

4. The battery management system according to claim 3, characterized in that: The cluster summary information includes key information and complete information, where: The key information is sent to the main management system through the inter-cluster bus, and the main management system controls the power access, energy management, power management and fault diagnosis of the entire battery system according to the key information of each battery cluster management system; The complete information is sent to the energy management system through the hierarchical bus, and the energy management system summarizes and records the operating data of the entire battery system according to the complete information to perform energy management of the entire battery system; The main management system forms an overall management strategy for the battery pack based on key information of some / all battery cluster management systems, or the energy management system forms an overall management strategy for the battery pack based on complete information of some / all battery cluster management systems; The management of the battery cluster summary information and / or overall management strategy and / or battery system also includes data configuration, remote monitoring, and system upgrades.

5. The battery management system according to claim 4, characterized in that: Each battery cluster management system is connected to an inter-cluster bus, and data is exchanged between the battery cluster management systems via the inter-cluster bus. The alternative primary management system is configured to act as the primary management system when the primary management system fails or has insufficient capacity; Each battery cluster management system transmits the collected battery pack information to the main management system through the inter-cluster bus; the main management system summarizes and processes the key information of the inter-cluster bus.

6. The battery management system according to claim 5, characterized in that: The main management system and the energy management system communicate via the first level bus to transfer key information; The main management system and the power conversion system communicate via the second-level bus to ensure the normal operation of the high-voltage management of the entire battery system; The energy management system and the power conversion system communicate through the third-level bus to meet the dispatching requirements of the station for battery system power or energy management; The battery cluster management system other than the main management system communicates with the energy management system via the fourth-level bus to transmit complete information; The transmission speed of the first-level bus is higher than the transmission speed of the fourth-level bus.

7. The battery management system according to claim 6, characterized in that: Each battery measurement unit communicates with the battery cluster management system of its cluster via CAN bus and / or daisy chain communication; Each battery cluster management system communicates via CAN bus / or Ethercat; Each battery cluster management system communicates with the energy management system via Ethernet; The main management system communicates with the energy management system via RS485 bus / or Ethernet, and the main management system communicates with the power conversion system via CAN bus; The energy management system communicates with the power conversion system via Ethernet.

8. The battery management system according to claim 7, characterized in that: The main management system is selected among the battery cluster management systems based on the operating status through competition rules, where the competition rules include: The performance calculation score is obtained by directly comparing the comprehensive weighted values ​​of the CPU load rate and RAM usage rate of each battery cluster management system. The lower the CPU load rate and RAM usage rate, the higher the performance calculation score. The battery cluster management system with the highest performance calculation score is selected as the main management system, or By comparing the number of election signals sent by each battery cluster management system in a unit time, the battery cluster management system that sends the most election signals in a unit time is selected as the main management system; When a battery cluster management system is selected as the main management system, its status remains unchanged during normal operation until a failure or insufficient capacity occurs, then competition will be resumed to achieve decentralized management of the battery system and one main and multiple backups.

9. The battery management system according to claim 8, characterized in that: When the main management system finds that the battery system has an alarm or fault, it informs the power conversion system of its current abnormal state through the CAN bus and informs the energy management system of its current abnormal state through the RS485 bus / or Ethernet; When the battery system has power or energy demand, the energy management system implements effective energy management of the battery system based on the status of the entire battery system, including: When the battery cluster of the battery system is low on power due to long-term storage and needs to be charged, the main management system sends a charging demand signal to the energy management system. The energy management system sends a charging instruction to the power conversion system based on the operating status of the battery system. The power conversion system charges the battery system on the DC side based on the current status of the main management system.

10. The battery management system according to claim 9, characterized in that: The energy management system communicates with the power conversion system via Ethernet. When the station places a dispatch demand on the power or energy of the battery system, the power conversion system is designated to perform dispatch, including: At the signal link level: When the station has a frequency regulation or peak regulation demand, the energy management system will issue a dispatch demand instruction to the power conversion system based on the station's demand. The power conversion system responds to the energy management system's demand based on the main management system's current power state and energy state, and feeds back the actual response data to the energy management system. At the power line level: the DC power at the energy storage end and the AC power at the grid end are converted into energy through the power conversion system.

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