Communication networking method of string type energy storage system

Abstract

The invention discloses a communication networking method of a string type energy storage system, which belongs to the field of energy storage system communication, and comprises the following steps: configuring a battery management system and a local control unit for each energy storage cabinet, forming an energy storage unit by a plurality of control cabinets, configuring a sub-array controller for each energy storage unit, and forming an energy storage system by a plurality of energy storage units. According to the invention, fine management and linkage control of a battery are realized, real-time transmission of data and accurate execution of instructions are ensured by adopting a communication network with dual-network redundancy configuration and an IEC 61850 standard communication protocol, efficient communication is realized, and when a single network link fails, the system can be seamlessly switched to a standby network, continuity and reliability of communication are ensured, and the service life of the system is prolonged. The communication between devices is more efficient and standardized, the compatibility and maintainability of the system are improved, the fault rate of the communication system of the large string type energy storage system can be greatly reduced, the control signal transmission time is greatly shortened, and the stability and efficiency of the communication of the energy storage system are ensured.

Description

Technical Field

[0001] The present invention belongs to the field of energy storage system communication, and in particular relates to a communication networking method for a string type energy storage system. Background Art

[0002] As the global demand for renewable energy continues to grow, large-scale energy storage systems are playing an increasingly important role in power systems. However, traditional energy storage systems have low standardization and poor battery management. When facing large-scale, highly complex string energy storage systems, communication networking methods often suffer from unstable communications, low data transmission efficiency, and difficult system maintenance. These problems not only affect the overall performance of the energy storage system, but also limit its full role in the power system. Summary of the invention

[0003] 1. Technical issues to be resolved In order to overcome the shortcomings of the existing technology, a communication networking method for a string energy storage system is proposed to solve the problems of low standardization and poor battery management of traditional energy storage systems. When facing large-scale and highly complex string energy storage systems, communication networking methods often have problems such as unstable communication, low data transmission efficiency, and difficult system maintenance.

[0004] (II) Technical solution The present invention is implemented by the following technical solution: The present invention proposes a communication networking method for a string energy storage system, comprising the following steps: Step 1: Setting up a battery management system (BMS) for the energy storage cabinet. The battery management system (BMS) is used for accurate collection and management of battery parameters; The battery management system (BMS) is provided with multiple levels, and the multiple levels of the battery management system (BMS) are divided into two parts: a slave control module and a master control module, which are used to collect and manage the voltage, temperature, current and other information of the energy storage battery system in a refined manner, thereby improving the refinement level of battery management. The battery management system (BMS) slave control and the battery management system (BMS) master control use CAN communication, and the battery management system (BMS) master control and the energy storage converter (PCS) use CAN communication, and output a dry contact signal to the energy storage converter (PCS) for linkage shutdown; Step 2: Configuring a local control unit (LCU) for the energy storage cabinet, wherein the local control unit (LCU) is used for local control of the energy storage cabinet and for communication with an upper-level controller; Each energy storage cabinet is equipped with a local control unit (LCU). RS485 communication is used between the local control unit (LCU) and the energy storage converter (PCS). The local control unit (LCU) and the BMS main control are connected by LAN port. MODBUS-TCP communication protocol is used between the local control unit (LCU) and the battery management system (BMS) main control module, and IEC 104 communication protocol is used with the upper-level array controller (EMU). RS485 communication is used between the local control unit (LCU) and the display screen. The local control unit (LCU) has multiple DI / DO points, among which the DI interface is mainly connected to: fire system early warning signal, fire system fire alarm signal, access control travel switch signal, water sensor signal and emergency stop switch signal, and the DO interface is mainly connected to the energy storage cabinet indicator light and the battery management system (BMS) dry contact; Step 3: forming a sub-array energy storage unit through a plurality of the energy storage cabinets, and constructing a communication network architecture of the energy storage unit; Step 4: configuring a subarray controller (EMU) for the energy storage unit, wherein the subarray controller (EMU) is used to collect and manage data of all energy storage cabinets in the subarray and perform linkage control at the same time; The sub-array controller (EMU) and the local control unit (LCU) of the energy storage cabinet adopt the IEC 104 communication protocol, the data network port of the sub-array controller (EMU) and the energy storage converter (PCS) adopts the IEC 61850-MMS communication protocol, the control network port of the sub-array controller (EMU) and the energy storage converter (PCS) adopts the IEC 61850-GOOSE communication protocol, and the sub-array controller (EMU) adopts a dual network redundant configuration of data network and control network in the north direction; Each energy storage unit is configured with one subarray controller (EMU); Step 5: Setting the communication network between the subarray controller (EMU) and the energy storage cabinet to adopt a dual-network system with independent data network and control network, that is, the LAN port of the local control unit (LCU) of the energy storage cabinet and the data network LAN port of the energy storage converter (PCS) are connected to the energy storage unit data network switch, and at the same time, the LAN port of the control network of the energy storage converter (PCS) is connected to the energy storage unit control network switch; The sub-array controller (EMU) has multiple LAN ports, of which one data network LAN port is connected to the energy storage unit data network switch, and one control network LAN port is connected to the energy storage unit control network switch. The sub-array controller (EMU) adopts dual-network redundancy configuration for the upper system, i.e. dual data network and dual control network, and reserves more than two LAN ports for access to box-type transformer measurement and control devices; The control network of the subarray controller (EMU) adopts the IEC 61850-GOOSE communication protocol, and the data network adopts the IEC61850-MMS communication protocol; Step 6: The plurality of energy storage units form an energy storage system, a station control layer energy management system (EMS) is configured for the energy storage system, and the station control layer communication network architecture is performed; Step 7: The communication network of the station control layer adopts a dual-network redundant communication network. The dual-network redundant communication network adopts a dual-network redundant design with a data network and a control network separated, ensuring that when one network link fails, the other network link can quickly take over the communication task, thereby improving the communication reliability of the system; Step 8: The station control layer communicates with the energy storage unit through the array controller (EMU); Furthermore, the communication network of the station control layer adopts the IEC 61850 standard communication protocol.

[0005] Furthermore, the data network of the station control layer adopts the IEC 61850-MMS communication protocol for transmitting a large amount of monitoring data and log information, and the control network of the station control layer adopts the IEC 61850-GOOSE communication protocol, which has the characteristics of strong real-time performance and high priority, and is suitable for transmitting control instructions and status information.

[0006] Furthermore, the station control layer adopts an energy management system, and the station control layer energy management system network adopts a dual data network and a dual control network, and the network structure is a star type.

[0007] Furthermore, the main equipment of the energy management system is the EMS server and the coordination controller, and the main equipment adopts a redundant configuration.

[0008] Furthermore, the EMS server is connected to a data network, and the monitoring data and log information are transmitted through the data network using the IEC 61850-MMS protocol. The coordination controller is connected to a control network, and the control instructions and status information are transmitted using the IEC 61850-GOOSE protocol.

[0009] Furthermore, the IEC 61850 standard object-oriented modeling technology and abstract communication service interface ACSI are used to achieve efficient and standardized communication between devices. At the same time, the GOOSE service is used for the rapid transmission of real-time control instructions and status information, and the MMS service is used for the reliable transmission of non-real-time data.

[0010] Furthermore, message priority processing is set, and the priority / virtual LAN identification field defined by the VLAN tag carried by the GOOSE message is ensured to ensure that high-priority messages can be transmitted first or separated from other network traffic, thereby improving the real-time and reliability of data transmission.

[0011] Furthermore, in terms of system operation and management, unified configuration and management have been achieved. Through the unified modeling and naming rules of the IEC 61850 standard, unified configuration and management of each device in the system are achieved, simplifying the system maintenance process.

[0012] Furthermore, in terms of system operation and management, rapid fault location and recovery are achieved. Through dual-network redundant configuration and standardized communication protocols, the system can quickly locate communication failures and recover them, thereby improving the overall stability and availability of the system.

[0013] (III) Beneficial effects One of the above technical solutions has the following advantages or beneficial effects: In order to solve the problems of low standardization and poor battery management of traditional energy storage systems, communication networking methods often encounter problems such as unstable communication, low data transmission efficiency, and difficult system maintenance when facing large-scale and highly complex string energy storage systems. By configuring a battery management system and a local control unit for each energy storage cabinet, and combining multiple control cabinets into an energy storage unit, each energy storage unit is configured with a sub-array controller, and then multiple energy storage units are used to form an energy storage system, an energy management system is configured for the energy storage system to achieve refined management and linkage control of batteries, and by adopting a dual-network redundant communication network and IEC 61850 standard communication protocol, real-time data transmission and accurate execution of instructions are ensured to achieve efficient communication, and when a single network link fails, the system can be seamlessly switched to the backup network to ensure the continuity and reliability of communication, making communication between devices more efficient and standardized, and improving the compatibility and maintainability of the system. Many problems existing in the communication of large-scale string energy storage systems are solved, and the failure rate of the communication system of large-scale string energy storage systems can be greatly reduced, and the control signal transmission time is greatly reduced, ensuring the stability and efficiency of energy storage system communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 This is a schematic diagram of the communication architecture of the energy storage cabinet of the present invention; Figure 2 A schematic diagram of the communication architecture of the energy storage unit of the present invention; Figure 3 This is a flow chart of message priority processing of the present invention; DETAILED DESCRIPTION

[0015] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0016] The present invention provides a communication networking method for a string energy storage system: an energy storage system with a rated total capacity of 100MW / 200MWh is set up and divided into 20 energy storage units, each of which contains 24 215kW / 418kWh energy storage cabinets, the energy storage cabinets use 314Ah lithium iron phosphate batteries, and a single energy storage cabinet is composed of 8 1P52S battery packs, 1 high-voltage box, 1 215kW PCS, 1 liquid cooling unit, 1 perfluorohexanone fire protection system and other auxiliary systems; The entire communication system adopts a layered architecture and is divided into three layers, namely the station control layer, the energy storage unit layer, and the energy storage equipment layer. The energy storage equipment layer refers to the communication network within the energy storage cabinet; the energy storage unit layer refers to the communication network of the energy storage cabinet, box-type transformer and other equipment within the energy storage unit; the station control layer refers to the communication network of the energy storage EMS system and energy storage unit-related equipment; The details are as follows: 1. Energy storage equipment layer: Each energy storage cabinet adopts a standard network architecture. Each battery pack is equipped with a battery management system (BMS) slave control module. A single energy storage cabinet is equipped with a total of 8 battery management system (BMS) slave control modules and 1 battery management system (BMS) master control module. CAN communication is adopted between the battery management system (BMS) slave control and the battery management system (BMS) master control. CAN communication is adopted between the battery management system (BMS) master control and the energy storage converter (PCS), and a dry contact signal is output to the energy storage converter (PCS) for linkage shutdown; At the same time, each energy storage cabinet is equipped with a local control unit (LCU), which is responsible for the local control of the energy storage cabinet and the communication with the upper controller. The local control unit (LCU) communicates with the energy storage converter (PCS) using RS485, and is connected to the battery management system (BMS) main control using the LAN port, using the MODBUS-TCP communication protocol, and using the IEC104 communication protocol with the upper sub-array controller (EMU). The local control unit (LCU) and the display screen communicate using RS485. The local control unit (LCU) has multiple DI / DO points, among which the DI interface is mainly connected to: fire system early warning signal, fire system fire alarm signal, access control travel switch signal, water sensor signal and emergency stop switch signal. The DO interface of the local control unit (LCU) is mainly connected to the energy storage cabinet indicator light and the battery management system (BMS) dry contact.

[0017] 2. Energy storage unit layer: Each energy storage unit is composed of multiple energy storage cabinets. Each energy storage unit is equipped with a sub-array controller (EMU). The sub-array controller (EMU) is responsible for collecting and managing the data of all energy storage cabinets in the sub-array, performing linkage control at the same time, and is responsible for communicating with the upper-level EMS system. The sub-array controller (EMU) and the energy storage cabinet communicate using a dual-network system with independent data network and control network. The data network port of the sub-array controller (EMU) and the energy storage converter (PCS) uses the IEC 61850-MMS communication protocol, and the control network port of the sub-array controller (EMU) and the energy storage converter (PCS) uses the IEC 61850-GOOSE communication protocol. The sub-array controller (EMU) uses a dual-network redundant configuration of data network and control network in the north direction. The LAN port of the local control unit (LCU) of the energy storage cabinet and the data network LAN port of the energy storage converter (PCS) are connected to the data network switch of the energy storage unit. At the same time, the control network LAN port of the energy storage converter (PCS) is connected to the energy storage unit control network switch. The sub-array controller (EMU) has 8 LAN ports, of which 1 data network LAN port is connected to the energy storage unit data network switch, and 1 control network LAN port is connected to the energy storage unit control network switch. The sub-array controller (EMU) adopts dual-network redundant configuration for the upper-level EMS, namely dual data network and dual control network, and reserves 2 LAN ports for access to box-type transformer measurement and control devices. The control network of the sub-array controller (EMU) adopts the IEC61850-GOOSE communication protocol, and the data network of the sub-array controller (EMU) adopts the IEC 61850-MMS communication protocol.

[0018] 3. Station control layer EMS network: The station control layer EMS network adopts dual data networks and dual control networks, and the network structure is star-shaped. The main equipment of the EMS system is the EMS server and the coordination controller. The main equipment is redundantly configured. The EMS server is connected to the data network, and the data network adopts the IEC 61850-MMS protocol to transmit monitoring data and logs and other information. The coordination controller is connected to the control network, and the control network adopts the IEC 61850-GOOSE protocol to transmit control instructions and status information. In the dual-network structure, when any network link fails, the other network link can quickly take over the communication task to ensure the normal operation of the system.

[0019] The present invention configures a multi-level battery management system, an on-site control unit and a subarray controller, and adopts a dual-network redundant communication network and the IEC 61850 standard communication protocol. According to the actual application of large-scale string energy storage projects, the present invention successfully solves many problems existing in the communication of large-scale string energy storage systems. The failure rate of the communication system is ≤0.001%, and the control signal transmission time is ≤100ms, ensuring the stability and efficiency of the energy storage system communication.

[0020] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0021] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A communication networking method for a string energy storage system, characterized in that: The method comprises the following steps: Step 1: Setting up a battery management system for the energy storage cabinet, wherein the battery management system is used for accurate collection and management of battery parameters; Step 2: configuring a local control unit for the energy storage cabinet, wherein the local control unit is used for local control of the energy storage cabinet and for communication with an upper-level controller; Step 3: forming a sub-array energy storage unit through a plurality of the storage cabinets, and constructing a communication network architecture of the energy storage unit; Step 4: configuring a subarray controller for the energy storage unit, wherein the subarray controller is used to collect and manage data of all energy storage cabinets in the subarray and perform linkage control at the same time; Step 5: Setting the communication network between the subarray controller and the energy storage cabinet to adopt a dual network system with independent data network and control network; Step 6: The plurality of energy storage units form an energy storage system, a station control layer energy management system is configured for the energy storage system, and the station control layer communication network architecture is performed; Step 7: The communication network of the station control layer adopts a dual-network redundant communication network, and the dual-network redundant communication network adopts a dual-network redundant design in which a data network and a control network are separated; Step 8: The station control layer communicates with the energy storage unit through the subarray controller.

2. A communication networking method for a string energy storage system according to claim 1, characterized in that: The communication network of the station control layer adopts the IEC 61850 standard communication protocol, the data network of the station control layer adopts the IEC61850-MMS communication protocol, and the control network of the station control layer adopts the IEC61850-GOOSE communication protocol.

3. The communication networking method of a string energy storage system according to claim 1, characterized in that: The battery management system is provided with multiple levels, and the multiple levels of the battery management system are divided into two parts: a slave control module and a master control module.

4. The communication networking method of a string energy storage system according to claim 3, characterized in that: The main control module of the battery management system communicates with the energy storage converter using CAN, and outputs a dry contact signal to the energy storage converter for linkage shutdown. The energy storage converter communicates with the local control unit using RS485.

5. A communication networking method for a string energy storage system according to claim 1 or 4, characterized in that: The local control unit uses the MODBUS-TCP communication protocol with the main control module of the battery management system, and uses the IEC 104 communication protocol with the upper-level sub-array controller.

6. A communication networking method for a string energy storage system according to claim 5, characterized in that: The local control unit is also connected to a fire protection system early warning signal, a fire protection system fire alarm signal, a door access control travel switch signal, a water immersion sensor signal, an emergency stop switch signal, an energy storage cabinet indicator light and a battery management system dry contact.

7. A communication networking method for a string energy storage system according to claim 1, characterized in that: The subarray controller and the local control unit of the energy storage cabinet adopt the IEC 104 communication protocol, the data network port of the subarray controller and the energy storage inverter adopts the IEC 61850-MMS communication protocol, the control network port of the subarray controller and the energy storage inverter adopts the IEC 61850-GOOSE communication protocol, and the subarray controller adopts a dual network redundant configuration of data network and control network in the north direction.

8. The communication networking method of a string energy storage system according to claim 1, characterized in that: The station control layer adopts an energy management system, and the station control layer energy management system network adopts a dual data network and a dual control network, and the network structure is a star type.

9. A communication networking method for a string energy storage system according to claim 8, characterized in that: The main equipment of the EMS system is the EMS server and the coordination controller, and the main equipment is redundantly configured.

10. A communication networking method for a string energy storage system according to claim 9, characterized in that: The EMS server is connected to a data network, and the data network uses the IEC 61850-MMS protocol to transmit monitoring data and log information; the coordination controller is connected to a control network, and the control network uses the IEC 61850-GOOSE protocol to transmit control instructions and status information.

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