Architecture and design of a remote operation and maintenance master station for power equipment

The study aims to alleviate the pressure of operation and maintenance of primary and secondary power equipment and improve the work efficiency of operation and maintenance personnel. It explores the early elimination of safety hazards in power equipment and hopes to ensure the safe operation of the power grid. This article designs a remote operation and maintenance master station architecture for power equipment, through specialized power operation and maintenance communication protocols and file transmission methods. It summarizes data to the operation and maintenance master station. The data is then analyzed and processed. The operation and maintenance personnel of equipment with safety hazards are promptly notified. Further, the study distinguishes whether faulty equipment needs on-site operation and maintenance through intelligent technology. It provides remote operation and maintenance functions for power equipment. It reduces the number of on-site operations and maintenance personnel. It improves the level of refined management and operation and maintenance capabilities of equipment. The study has a certain reference value for remote operation and maintenance technology of power equipment.


Introduction
With the modernization of China's power grid and the rapid increase of primary and secondary equipment, it is expected that the number of connected terminal devices will exceed 1 billion by 2025 and 2 billion by 2030, with a compound annual growth rate of about 12%.This can cause a sharp increase in the pressure on the operation and maintenance of primary and secondary equipment in the power grid year by year, increasing security risks [1][2] in the power grid.
Due to the large number of equipment manufacturers and wide location distribution, the agreement is different.Hence, the difficulty of operation and maintenance is high.There is no independent main station that can support remote operation and maintenance of power equipment.The current operation and maintenance functions are mainly integrated into the distribution network automation master station, which not only occupies the resources of the dispatch master station but also may affect the safety of power grid dispatch.
The main purpose of this article is to develop and design a remote operation and maintenance master station architecture for power equipment.The aim is to assist operation and maintenance personnel in reducing power grid safety hazards, eliminating risks and defects of power equipment [3] , and reducing operation and maintenance pressure.The remote operation and maintenance master station [4] combines specialized distribution operation and maintenance protocols and data transmission methods to complete data collection, analysis, and processing of primary and secondary equipment [5] .By providing intelligent technical means, we can promptly identify problems and manage the entire process of equipment operation and maintenance work orders.

Master station design
The remote operation and maintenance main station mainly includes three parts, namely front-end service, information management area, and production control area.The operation and maintenance main station analyzes the real-time and historical operation data of power grid equipment.It intelligently diagnoses and evaluates the operation status of power equipment.It provides alarm notifications for problematic equipment and generates corresponding operation and maintenance work orders for submission to operation and maintenance personnel for processing.The operation and maintenance main station also provides remote operation and maintenance functions, allowing operation and maintenance personnel to choose operation and maintenance methods based on actual situations.

System hardware design
The main server hardware structure of the system is shown in Figure 1.Front-end services are deployed in the secure access area to collect device information.The front-end services use specialized operation and maintenance protocols and are deployed in a pluggable form to facilitate subsequent updates and replacements of operation and maintenance protocols.In the production control area, a data processing server is used to parse, process, and store the received data.The remote operation and maintenance master station is used for security audits, operation, and maintenance channel start and stop approval operations.The remote operation and maintenance dedicated machine is used for remote operation and maintenance of equipment and related operation log records.In the management information area, the role of the front-end server is the same as that of the front-end service in the security access area.It adopts the same set of protocols to reduce development volume.The remote operation and maintenance management server is used for visualizing operation and maintenance data and managing the entire process of operation and maintenance work orders.The data processing server is used to parse, process, and store the received data.At the same time, the data that needs to be transmitted to the production control area is packaged into files.It is transmitted to the production control area and remote operation and maintenance workstation through forward and reverse isolation devices for monitoring the operation status and system environment of the remote operation and maintenance system.

System software architecture
The production control region architecture is divided into three layers, as shown in Figure 2. The infrastructure mainly includes the network, operating system, docker, and image library, which are the hardware environment, network environment, system environment, and deployment middleware required for the normal operation of the system.The storage layer mainly provides database energy storage tools such as relational databases, temporal databases, historical databases, and memory databases, as well as energy storage methods such as file energy storage and object energy storage.The system layer is centered around the main system, with auxiliary modules providing different functional services and common components.In the system layer, each functional service is independent of the other, handling business independently, and is deployed independently.Through custom communication protocols, messages are passed to each functional service on the virtual bus.Common components mainly provide a database access library, memory access library, permission control library, interface component library, etc.The management information area is mainly divided into six layers, as shown in Figure 3.The infrastructure and storage layer are similar to the production control area.The middle layer mainly includes components or frameworks that support business services such as message queues such as MQ, Kafka, ORM technology, JWT, etc.The business layer is mainly divided according to different business functions and provides standardized interfaces.Each functional service is independent of each other and processes its own business.Each service is called and accessed through methods such as HTTP and service bus.The presentation layer mainly includes front-end and back-end data interaction technologies, such as Ajax, Axios, and other front-end and back-end ResultFul interface interactions, and Websocket and other front-end and back-end socket interactions.The front-end layer mainly implements the technologies used for front-end display, including React, VUE, CSS3, HTML, and other front-end UI technologies, rendering technologies, and back-end access methods.

Overall design architecture
Figure 4 shows the overall design architecture of the system.The system deploys corresponding functions in modular, APP, component, and other replaceable ways.Modules communicate with each other through virtual service buses, and updates to corresponding modules do not affect the use of other modules.The control management regional operation and maintenance system includes the following main modules: operation and maintenance main system, transaction bus module, communication acquisition module, data processing module, data transmission module, and process daemon module.
The production management regional operation and maintenance management system includes the following main modules: operation and maintenance management main system, business module, communication collection service, data processing service, data transmission service, access service, permission service, and data storage.

Communications architecture
The communication framework of the system is shown in Figure 5.The system uses a dedicated operation and maintenance protocol for remote operation and maintenance.The specific business communication process is as follows: if there is an abnormality in the equipment or an alarm message, the main station notifies the management personnel, and the management personnel confirms with one click to generate an operation and maintenance work order.The work order is approved by the main station in the production control area.The approved operation and maintenance work order is sent to the operation and maintenance personnel.The operation and maintenance personnel carry out operation and maintenance through the operation and maintenance host.The operation and maintenance process is as follows: when the work order is approved, the main station opens the equipment operation and maintenance channel; the operation and maintenance personnel conduct remote operation and maintenance through the operation and maintenance channel.If the equipment supports remote operation and maintenance protocols, the data is exchanged through this protocol.If the remote operation and maintenance protocols are not supported, a dedicated communication module needs to be installed.This communication module packages the collected equipment data into a file and sends it to the main station in the form of a file.The main station installs the file parsing plugin for the corresponding device to parse and store data, in order to improve the viewing of operation and maintenance personnel.The distribution terminal intelligent management unit distribution operation and maintenance platform (control and management area) includes three communication channels.The security audit channel is normally connected.It is used to approve the start and stop applications of the operation and maintenance channel, and issue orders to open corresponding operation and maintenance channels for approved applications.The operation and maintenance data channel of the power distribution terminal is opened after receiving corresponding instructions, which is used for data interaction with the power distribution terminal.The main method of uploading operation and maintenance data files is through data transmission.The intelligent management unit operation and maintenance channel is mainly used to interact with the intelligent management unit.The interaction methods include data flow and files, mainly including emergency safety alarm data.
Intelligent job terminal -distribution operation and maintenance platform (production management area): No application is required.There are mainly interactive operation and maintenance work order information, on-site operation and maintenance records, and operation and maintenance data.
Low voltage monitoring equipment -Global Internet of Things platform -Distribution operation and maintenance platform (production management region): The MQTT protocol is used to ensure access to massive equipment.
Other: E files and DAT file interaction are commonly used.

Operation and maintenance communication protocol
The operation and maintenance communication protocol [6][7][8][9] , with the communication format shown in Table 1 and Table 2, adopts the large end byte order method for communication message transmission.The first two bytes of 8 represent the manufacturer's code, using uppercase letters.Last two bytes indicates the manufacturer's identification code for each online monitoring device, using uppercase letters and numbers, with priority given to numbers

System functional architecture
The functional framework of the system is shown in Figure 6.There are data processing services, data transmission services, data access services, device terminal management and data visualization services, operation and maintenance work order management and data visualization services, intelligent detection and judgment and data visualization services, security audit, system management: user permission and role management, security system management, intelligent alarm, remote operation channel control, device parameter management, software version management, user security management, log management remote port access, and security auditing.

System verification
Figure 7 shows a schematic diagram of the work order approval interface, which is developed in a modular manner and supports multiple query criteria.It looks at the time period, functional location, task type, inspection location, work order number, work order source, approval result, and other conditions to query.When the work order is approved, a notification will be automatically issued to the device to open the operation and maintenance channel.If there is no node at the end time of the work order, the operation and maintenance channel will be automatically closed to the device.The source of work orders mainly includes system generation and platform input, mainly generated by the system based on algorithms or one click generation.Platform input is mainly used to compensate for system generated omissions and emergency operation and maintenance events.Figure 8 shows the operation and maintenance work order process management interface, where the latest process status of the operation and maintenance work order can be queried.At the same time, the operation and maintenance work order can be added, modified, or revoked.The left side of the page is the equipment tree.The hierarchical relationships of the equipment tree are all, equipment manufacturer level, belonging to the distribution station level, and specific equipment level.The window on the right side of the corresponding device tree is selected to dynamically change.Figure 9 shows the device operation and maintenance interface.It mainly includes viewing and remotely modifying the basic parameters of the device, the online status of the device, whether the operation and maintenance channel is connected or disconnected, and remote real-time viewing of the device operation parameters.The operation and maintenance personnel need to ensure that the device is online and that the operation and maintenance channel is opened and connected.Based on real-time operation parameter information, remote operation, maintenance, and configuration of device configuration information are performed.

Conclusion
At present, due to the investment in power equipment, the workload of operation and maintenance of power equipment is large, the efficiency is low and the maintenance cost is high.Therefore, this article designs a remote operation and maintenance master station architecture for power equipment.It mainly achieves the interaction and remote operation and maintenance between devices and the main station through a set of specialized remote operation and maintenance protocols.The main station deploys functional applications through plugins, modularity, and APPs to achieve flexible expansion of the main station.The stock equipment achieves remote operation and maintenance work of the stock equipment through data file transmission and the main station.It is achieved according to the corresponding equipment manufacturer's operation and maintenance plugins, thereby reducing the investment in the transformation of the stock equipment.By analyzing and processing equipment operation data through the operation and maintenance master station, equipment problems can be identified in a timely manner.The frequency of on-site equipment inspections can be reduced by operation and maintenance personnel.The level of refined equipment management can be improved.This is of great significance for the remote maintenance technology of equipment.

Figure 2 .
Figure 2. Software architecture of production control region.The management information area is mainly divided into six layers, as shown in Figure3.The infrastructure and storage layer are similar to the production control area.The middle layer mainly includes components or frameworks that support business services such as message queues such as MQ, Kafka, ORM technology, JWT, etc.The business layer is mainly divided according to different business functions and provides standardized interfaces.Each functional service is independent of each other and processes its own business.Each service is called and accessed through methods such as HTTP and service bus.The presentation layer mainly includes front-end and back-end data interaction technologies, such as Ajax, Axios, and other front-end and back-end ResultFul interface interactions, and Websocket and other front-end and back-end socket interactions.The front-end layer mainly implements the technologies used for front-end display, including React, VUE, CSS3, HTML, and other front-end UI technologies, rendering technologies, and back-end access methods.

Figure 3 .
Figure 3. Software architecture of information management region.

Figure 4 .
Figure 4. Overall design architecture.The control management regional operation and maintenance system includes the following main modules: operation and maintenance main system, transaction bus module, communication acquisition module, data processing module, data transmission module, and process daemon module.The production management regional operation and maintenance management system includes the following main modules: operation and maintenance management main system, business module, communication collection service, data processing service, data transmission service, access service, permission service, and data storage.

Figure 5 .
Figure 5. Communication architecture.The distribution terminal intelligent management unit distribution operation and maintenance platform (control and management area) includes three communication channels.The security audit channel is normally connected.It is used to approve the start and stop applications of the operation and maintenance channel, and issue orders to open corresponding operation and maintenance channels for approved applications.The operation and maintenance data channel of the power distribution terminal is opened after receiving corresponding instructions, which is used for data interaction with the power distribution terminal.The main method of uploading operation and maintenance data files is through data transmission.The intelligent management unit operation and maintenance channel is mainly used to interact with the intelligent management unit.The interaction methods include data flow and files, mainly including emergency safety alarm data.Intelligent job terminal -distribution operation and maintenance platform (production management area): No application is required.There are mainly interactive operation and maintenance work order information, on-site operation and maintenance records, and operation and maintenance data.Low voltage monitoring equipment -Global Internet of Things platform -Distribution operation and maintenance platform (production management region): The MQTT protocol is used to ensure access to massive equipment.Other: E files and DAT file interaction are commonly used.

Figure 6 .
Figure 6.Functional architecture.3.System verificationFigure7shows a schematic diagram of the work order approval interface, which is developed in a modular manner and supports multiple query criteria.It looks at the time period, functional location, task type, inspection location, work order number, work order source, approval result, and other conditions to query.When the work order is approved, a notification will be automatically issued to the device to open the operation and maintenance channel.If there is no node at the end time of the work order, the operation and maintenance channel will be automatically closed to the device.The source of work orders mainly includes system generation and platform input, mainly generated by the system based on algorithms or one click generation.Platform input is mainly used to compensate for system generated omissions and emergency operation and maintenance events.

Figure 7 .
Figure 7. Work order approval interface.Figure8shows the operation and maintenance work order process management interface, where the latest process status of the operation and maintenance work order can be queried.At the same time, the operation and maintenance work order can be added, modified, or revoked.The left side of the page is the equipment tree.The hierarchical relationships of the equipment tree are all, equipment manufacturer level, belonging to the distribution station level, and specific equipment level.The window on the right side of the corresponding device tree is selected to dynamically change.

Figure 8 .
Figure 8. Work order management interface.Figure9shows the device operation and maintenance interface.It mainly includes viewing and remotely modifying the basic parameters of the device, the online status of the device, whether the operation and maintenance channel is connected or disconnected, and remote real-time viewing of the device operation parameters.The operation and maintenance personnel need to ensure that the device is online and that the operation and maintenance channel is opened and connected.Based on real-time operation parameter information, remote operation, maintenance, and configuration of device configuration information are performed.

Figure 9 .
Figure 9. Equipment operation and maintenance interface.

Table 1 .
General format of data frames.

Table 2 .
General format for device numbers.