An asymmetric communication system under a PCS architecture of an energy storage power station central controller

Abstract

The application relates to an asymmetric communication system under a PCS framework of an energy storage power station central controller, which comprises a coordination controller, a PCS module and an energy storage module; the PCS module comprises a PCS central controller and a plurality of PCS units connected with the PCS central controller; the energy storage module comprises an energy storage subsystem master control unit and a plurality of energy storage subsystems connected with the energy storage subsystem master control unit; the plurality of PCS units are used for realizing bidirectional power exchange between the plurality of energy storage subsystems and a direct-current bus or an alternating-current bus; the PCS central controller is connected with the energy storage subsystem master control unit through a low-speed channel and a high-speed channel respectively, and is connected with the coordination controller through an emergency stop instruction channel; and the PCS central controller executes corresponding control strategies on the PCS units according to off-grid and grid-connected states based on control instructions of the energy storage subsystem master control unit to realize power regulation. The application can realize individualized management and is suitable for communication control under application scenarios of energy storage power stations such as rapid response and high-speed frequency modulation.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, and in particular to an asymmetric communication system under a centralized controller-type PCS architecture for energy storage power stations. Background Technology

[0002] An energy storage power station is a system that uses electrochemical batteries or electromagnetic devices as the energy storage medium and employs storage, conversion, and release methods to regulate electrical energy. Currently, energy storage power stations mainly serve functions such as peak-valley regulation, electricity transfer and storage, and new energy consumption.

[0003] Converter systems (PCS) for energy storage power stations can be divided into two categories: single-stage PCS and two-stage PCS. Single-stage topologies use a single AC / DC module to form the converter unit, directly connecting the energy storage unit to the AC / DC module. They are characterized by high efficiency and simple structure, but suffer from a narrow voltage input range and strict requirements for the voltage level of the series-connected batteries, hindering the large-scale development of energy storage power stations. Two-stage topologies use a combination of AC / DC and DC / DC modules to form the energy storage converter unit. By adding a DC / DC module between the energy storage unit and the AC / DC module, two-stage PCS allows for a wider input voltage range, more flexible power control, and good structural scalability. It enables fine-grained management of multiple energy storage clusters, with each cluster capable of independent management. However, it suffers from complex control and slightly lower efficiency.

[0004] The core control system of current energy storage power stations includes three subsystems: the Energy Management System (EMS), the Battery Management System (BMS), and the Process Control System (PCS). After the master dispatch station issues commands to the EMS, the EMS, by integrating the status data from the BMS and PCS, issues the final control commands to the PCS. The BMS serves only as reference information in the control framework. However, the BMS, as a module that directly manages the energy storage units, lacks control participation weight, which is detrimental to the rapid response of energy storage safety. Furthermore, in large-scale energy storage power station applications, the number of energy storage units and their corresponding PCS units is large, and the control is complex. Different control units and modules have different communication requirements, necessitating customized handling of communication methods between each module.

[0005] To address the aforementioned issues, some institutions and scholars have designed architectures for energy storage power stations, hoping to solve the problems of weak control links and low security in energy storage power stations by designing a new management and control architecture. The paper ("Energy Storage System Design to Improve Safety Performance") proposes a management and control architecture for energy storage system safety issues. Compared to traditional energy storage system architectures, the designed safety management and control architecture focuses on enhancing the role of the Battery Management System (BMS) in system management. Unlike traditional energy storage power stations, this research draws on the approach of new energy electric vehicles, where the vehicle controller (equivalent to the EMS) is responsible for issuing commands to the BMS, and there is a data channel with the PCS. However, the final converter output is determined by the BMS based on the overall cell status. This management and control architecture can solve the problem of rapid response, but it does not address the communication links between the energy storage system's EMS, PCS, BMS, energy storage units, security, and environmental control systems.

[0006] Besides batteries, energy storage units also include large-scale energy storage power station applications using hybrid supercapacitors (HUCs) as energy storage units. Correspondingly, a hybrid supercapacitor management system (CMS) is used instead of a battery management system. Similar to the aforementioned systems, however, a scientifically sound and reasonable management framework is lacking.

[0007] The existing patent document "Energy Storage Power Station and Communication Method Thereof (201611027042.X)" proposes a battery management system with RS485 and CAN as communication interfaces. The CAN bus is used as the fault data upload channel and RS485 is used as the conventional communication method. However, the system circuit is complex, and the CAN bus has a collision detection problem, which may result in untimely response when a fault occurs.

[0008] The existing patent document "A communication implementation method and system for a chain-type energy storage system (201210532386.1)" proposes a communication implementation method for an energy storage system using a ring communication optical fiber connection. However, the Ethernet protocol has a conflict detection problem and cannot respond in time during data blockage. The ring connection and chain communication also have the problem of complex wiring implementation.

[0009] The existing patent document "A method and system for managing energy storage power stations based on wireless communication (202111432034.4)" proposes a wireless communication method for managing energy storage power stations, but it mainly applies wireless communication to the environmental temperature control in the battery management system, rather than directly managing the EMS, PCS, BMS and energy storage unit control links.

[0010] The existing patent document "Wireless Networking Communication System and Method for Energy Storage System BMS (202010281264.4)" proposes a wireless networking communication system using a wireless BMS, which includes an energy management system, a battery array management unit, a bidirectional inverter, and a battery cluster. The battery cluster consists of a battery string management unit (BCU) and a battery module management unit (BMU) that exchange data via Bluetooth communication. External communication within the battery cluster uses Bluetooth-to-CAN communication. While this paper optimizes communication within the energy storage battery cluster using wireless communication, it does not consider electromagnetic interference issues in the energy storage power station environment. Furthermore, it only optimizes local communication between the BMS and energy storage units, without optimizing the communication links between the EMS, PCS, and BMS.

[0011] The existing patent document "An energy storage system and method for communication base stations with peak shaving and valley filling (202210071693.8)" proposes a method to add an Internet of Things (IoT) pipe to collect all data of the energy storage system to the cloud platform for processing. However, it lacks real-time performance between the command issuance links of the energy storage system. Remote cloud platform control will cause data communication delays and cannot respond in a timely manner.

[0012] Based on the patent search, no communication control methods were found for energy storage power station application scenarios such as providing personalized management between energy storage system EMS, PCS, BMS / CMS and energy storage units, security, and environmental control systems, or for fast response and high-speed frequency regulation. Summary of the Invention

[0013] The technical problem to be solved by the present invention is to provide an asymmetric communication system under the PCS architecture of the energy storage power station, which can realize personalized management and adapt to the communication control of energy storage power station application scenarios such as fast response and high-speed frequency regulation.

[0014] The technical solution adopted by this invention to solve its technical problem is as follows: An asymmetric communication system under a centralized controller-type PCS architecture for an energy storage power station is provided, including a coordination controller, a PCS module, and an energy storage module; the PCS module includes a PCS centralized controller and multiple PCS units connected to the PCS centralized controller; the energy storage module includes an energy storage subsystem main control unit and multiple energy storage subsystems connected to the energy storage subsystem main control unit; the multiple PCS units are used to realize bidirectional power exchange between the multiple energy storage subsystems and a DC bus or AC bus; the PCS centralized controller respectively uses low-speed channels and conflict-free... The high-speed arbitration channel is connected to the main control unit of the energy storage subsystem and to the coordination controller via an emergency stop command channel. The low-speed channel is used for data upload from the PCS unit, while the conflict-free high-speed arbitration channel is used for issuing control commands from the main control unit of the energy storage subsystem. The emergency stop command channel is used to enable the coordination controller to shut down the PCS central controller at a microsecond level in case of system failure. Based on the control commands from the main control unit of the energy storage subsystem, the PCS central controller executes corresponding control strategies on the PCS unit according to its off-grid and grid-connected status to regulate power.

[0015] The PCS central controller is connected to the plurality of PCS units via a high-speed channel that does not require conflict arbitration.

[0016] The energy storage subsystem includes an energy storage cluster management unit and multiple energy storage modules. Each energy storage module is equipped with an energy storage module management unit. The energy storage cluster management unit is connected to multiple energy storage module management units to collect the status data of individual energy storage units uploaded by the energy storage module management units. The energy storage cluster management unit is connected to the main control unit of the energy storage subsystem to upload the collected cluster data and receive instructions issued by the main control unit of the energy storage subsystem.

[0017] The energy storage subsystem is a hybrid supercapacitor energy storage system, a supercapacitor energy storage system, or a battery energy storage system.

[0018] The DC bus is connected to the AC bus via an AC / DC converter, and the AC bus exchanges power with the power grid through a booster compartment.

[0019] The coordination controller is connected to the dispatch master station and is used to receive the control instructions issued by the dispatch master station and send the control instructions to the energy storage module and the PCS module.

[0020] The coordination controller is connected to the local monitoring system and is used to upload status data from the energy storage module and the PCS module to the local monitoring system, and respond to control commands issued by the local monitoring system.

[0021] The coordination controller is connected to the security and environmental control system and is used to receive system environmental status data collected by the security and environmental control system, and issue instructions based on the system environmental status data to adjust the system environment.

[0022] Beneficial effects

[0023] Due to the adoption of the above technical solutions, this invention has the following advantages and positive effects compared with the prior art: In this invention, data between the BMS / CMS and PCS is uploaded via a low-speed channel, while control commands are issued via a high-speed channel without conflict arbitration. The use of a dual-channel asymmetric communication method effectively improves the response speed between the EMS, BMS / CMS, and PCS of the energy storage power station. This invention adopts a PCS control architecture with the PCS central controller as its core, and only has a high-speed emergency stop communication channel for the EMS, ensuring high-speed response under fault conditions. In this invention, the high-speed communication between the PCS central controller and PCS units without conflict arbitration ensures the timely issuance of control commands, reduces communication delays, and ensures that all energy storage converters are under synchronous control. Attached Figure Description

[0024] Figure 1 This is a structural block diagram of Embodiment 1 of the present invention;

[0025] Figure 2 This is a structural block diagram of Embodiment 2 of the present invention. Detailed Implementation

[0026] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0027] This invention relates to an asymmetric communication system under a centralized controller (PCS) architecture for an energy storage power station, comprising an EMS, a PCS module, and an energy storage module. The PCS module includes a PCS central controller and multiple PCS units connected to the central controller. The central controller acts as the master unit of the PCS module, and the remaining PCS units act as slave units. The energy storage module includes an energy storage subsystem master control unit (MCCU) and multiple energy storage subsystems connected to the MCCU.

[0028] In this embodiment, the EMS is connected to the dispatch master station to receive control commands issued by the master station and to distribute these commands to the energy storage module and the PCS module. The EMS is also connected to a local monitoring system to upload status data from the energy storage module and the PCS module and to respond to control commands issued by the local monitoring system. Furthermore, the EMS is connected to a security and environmental control system to receive system environmental status data collected by the system and to issue commands based on this data to adjust the system environment.

[0029] The PCS module in this embodiment adopts a topology combining a PCS central controller with multiple PCS units. These multiple PCS units enable bidirectional power exchange between the various energy storage subsystems and the DC or AC bus. The PCS central controller is connected to the MCCU via a low-speed channel and a high-speed channel (no conflict arbitration required), and to the EMS via an emergency stop command channel. The low-speed channel is used for data upload from the PCS units, the high-speed channel is used for issuing control commands from the main control unit of the energy storage subsystem, and the emergency stop command channel is used to enable the coordinating controller to shut down the PCS central controller at a microsecond level in the event of a system fault. In other words, the PCS central controller exchanges data with the MCCU, using the low-speed channel to upload large amounts of data from the PCS units and the high-speed channel to receive control commands from the MCCU. When a system short circuit or power anomaly occurs, the emergency stop command channel between the EMS and the PCS central controller enables a microsecond-level shutdown, ensuring a high-speed response under fault conditions. The PCS central controller, based on the control commands from the main control unit of the energy storage subsystem, executes corresponding control strategies on the PCS units according to their off-grid and grid-connected states to achieve power regulation. Furthermore, in this embodiment, the PCS central controller connects to multiple PCS units via a high-speed channel that eliminates the need for conflict arbitration. This ensures timely issuance of control commands, reduces communication delays, guarantees synchronous control of all PCS units, and provides a foundation for multi-unit parallel control.

[0030] The energy storage subsystem of this embodiment includes an energy storage cluster management unit and multiple energy storage modules. Each energy storage module is equipped with an energy storage module management unit. The energy storage cluster management unit is connected to multiple energy storage module management units and is used to collect the status data of individual energy storage cells uploaded by the energy storage module management units. The energy storage cluster management unit is connected to the main control unit of the energy storage subsystem and is used to upload the collected cluster data and receive instructions issued by the main control unit of the energy storage subsystem. It is worth mentioning that this energy storage subsystem can be any one of a hybrid supercapacitor energy storage system, a supercapacitor energy storage system, or a battery energy storage system.

[0031] In this embodiment, the DC bus is connected to the AC bus via an AC / DC converter, and the AC bus exchanges power with the power grid through a booster compartment.

[0032] The present invention will be further illustrated below through two specific embodiments.

[0033] Example 1: Decoupling Control Architecture for Single AC / DC Cascading Multiple DC / DC Units Based on CMS

[0034] In this embodiment, the emergency stop command between EMS and PCS can be achieved through high-speed communication using a dry node. The MCCU and PCS central controller can achieve an asymmetric dual-channel design using high-speed SPI communication and standard RS485 communication. Data exchange between MCCU and CCU can be achieved using CAN communication. AC / DC converters are configured separately, and the PCS central controller has high-speed data exchange channels with each DC / DC converter and AC / DC converter of the converter. This can be achieved using a multi-channel SCI fiber optic communication method based on a DSP and FPGA integrated development platform, enabling multi-machine parallel control of DC / DC converters and AC / DC control based on high-speed communication, without the need for conflict arbitration.

[0035] The PCS central controller primarily communicates with the EMS, CMS, and PCS units. An emergency stop command data channel exists between the PCS central controller and the EMS. When a system malfunctions and the MCCU cannot correctly issue malfunction handling commands, the EMS issues an emergency stop command to the PCS central controller. Two data exchange channels exist between the PCS central controller and the MCCU: a standard-speed exchange channel for uploading status information and a high-speed exchange channel for issuing control commands.

[0036] Example 2: One-to-one integrated DC / DC and AC / DC control architecture based on CMS

[0037] In this embodiment, the emergency stop command implementation between EMS and PCS can use a dry node to achieve high-speed communication. The MCCU and PCS central controller can use high-speed SPI communication and standard RS485 communication to achieve asymmetrical dual-channel communication. Data exchange between MCCU and CCU is achieved via CAN communication. With DC / DC and AC / DC integration, the PCS central controller only has a high-speed data exchange channel with the AC / DC side of the converter. This can be implemented using a multi-channel SCI fiber optic communication method based on a DSP and FPGA integrated development platform, enabling multi-machine parallel control of the AC / DC based on high-speed communication without the need for conflict arbitration.

[0038] The PCS central controller primarily communicates with the EMS, CMS, and PCS units. An emergency stop command data channel exists between the PCS central controller and the EMS. When a system malfunctions and the MCCU cannot correctly issue malfunction handling commands, the EMS issues an emergency stop command to the PCS central controller. Two data exchange channels exist between the PCS central controller and the MCCU: a standard-speed exchange channel for uploading status information and a high-speed exchange channel for issuing control commands.

[0039] It should be noted that the above two embodiments are not only applicable to hybrid supercapacitor energy storage systems, but also to supercapacitor energy storage systems and various battery energy storage systems (such as lead-acid battery energy storage systems, lithium battery energy storage systems, etc.). The energy storage unit in the above two embodiments can be not only a hybrid supercapacitor (HUC), but can also be extended to various generalized battery energy storage units (including but not limited to energy storage units of lead-acid batteries, lithium batteries, supercapacitors, hybrid supercapacitors, etc.), and the corresponding CMS can be replaced with BMS.

[0040] It is easy to see that in this invention, data between the BMS / CMS and PCS is uploaded via a low-speed channel, while control commands are sent via a high-speed channel. This dual-channel asymmetric communication method effectively improves the response speed between the EMS, BMS / CMS, and PCS of the energy storage power station. This invention adopts a PCS control architecture centered on the PCS central controller, with only an emergency stop high-speed communication channel for the EMS, ensuring high-speed response under fault conditions. In this invention, high-speed communication between the PCS central controller and PCS units ensures timely issuance of control commands, reduces communication delays, and guarantees synchronous control of all energy storage converters.

Claims

1. An asymmetric communication system under a centralized controller-type PCS architecture for an energy storage power station, characterized in that, The system includes a coordination controller, a PCS module, and an energy storage module. The PCS module includes a PCS central controller and multiple PCS units connected to it. The energy storage module includes an energy storage subsystem main control unit and multiple energy storage subsystems connected to it. The multiple PCS units are used to achieve bidirectional power exchange between the multiple energy storage subsystems and a DC or AC bus. The PCS central controller is connected to the energy storage subsystem main control unit via a low-speed channel and a high-speed channel without conflict arbitration, and to the coordination controller via an emergency stop command channel. The low-speed channel is used for data upload from the PCS units, and the high-speed channel is used for issuing control commands from the energy storage subsystem main control unit. The emergency stop command channel is used to enable the coordinated controller to shut down the PCS central controller at the microsecond level in the event of a system failure. Based on the control commands from the main control unit of the energy storage subsystem, the PCS central controller executes corresponding control strategies on the PCS units according to their off-grid and grid-connected states to regulate power. The energy storage subsystem includes an energy storage cluster management unit and multiple energy storage modules. Each energy storage module is equipped with an energy storage module management unit. The energy storage cluster management unit is connected to multiple energy storage module management units to collect the status data of the energy storage modules uploaded by these units. The energy storage cluster management unit is connected to the main control unit of the energy storage subsystem to upload the collected cluster data and receive commands from the main control unit.

2. The asymmetric communication system under the centralized controller-type PCS architecture of the energy storage power station according to claim 1, characterized in that, The PCS central controller is connected to the plurality of PCS units via a high-speed channel that does not require conflict arbitration.

3. The asymmetric communication system under the centralized controller-type PCS architecture of the energy storage power station according to claim 1, characterized in that, The energy storage subsystem is a hybrid supercapacitor energy storage system, a supercapacitor energy storage system, or a battery energy storage system.

4. The asymmetric communication system under the centralized controller-type PCS architecture of the energy storage power station according to claim 1, characterized in that, The DC bus is connected to the AC bus via an AC / DC converter, and the AC bus exchanges power with the power grid through a booster compartment.

5. The asymmetric communication system under the centralized controller-type PCS architecture of the energy storage power station according to claim 1, characterized in that, The coordination controller is connected to the dispatch master station and is used to receive the control instructions issued by the dispatch master station and send the control instructions to the energy storage module and the PCS module.

6. The asymmetric communication system under the centralized controller-type PCS architecture of the energy storage power station according to claim 1, characterized in that, The coordination controller is connected to the local monitoring system and is used to upload status data from the energy storage module and the PCS module to the local monitoring system, and respond to control commands issued by the local monitoring system.

7. The asymmetric communication system under the centralized controller-type PCS architecture of the energy storage power station according to claim 1, characterized in that, The coordination controller is connected to the security and environmental control system and is used to receive system environmental status data collected by the security and environmental control system, and issue instructions based on the system environmental status data to adjust the system environment.

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