Introduction: With the continuous expansion of urban gas pipeline networks, existing management methods and models can no longer meet the requirements of "rational planning, scientific management, safe gas supply, high-quality service, and reliable gas use." This article mainly introduces the architecture of a typical gas dispatch center SCADA system and the application of force control software in this system.
I. Overview
The SCADA system of the gas dispatch center involves various types of monitoring points, including gate stations, industrial users, gas stations, urban pipeline terminals, and pressure regulating stations. Real-time data from all monitoring points needs to be transmitted to the gas dispatch center for real-time monitoring by dispatch center operators and can be displayed on a centralized monitoring screen.
The SCADA system of the gas dispatch center can provide management with a stable, reliable, trustworthy and timely monitoring system. It can collect, screen, filter, statistically analyze, calculate and apply the operating parameters of local stations and depots across the country, and optimize and guide the production and operation of gas companies based on scientific data.
II. System Design Principles
Scalability – The system design should fully meet the needs of the current environment and the application needs for a period of time in the future, and at the same time, it should be easy to expand its functions and flexibly add or remove functional modules.
Integrability – From the perspective of technological development and user needs, the software structure itself should be able to integrate with other application systems to achieve information sharing and resource sharing.
Interoperability – Supports data interfaces for various mainstream real-time databases and achieves data integration with ERP and other MIS systems through standard relational database interfaces (such as ODBC and OLEDB). The platform's openness ensures that different functions can be tailored from different data modules of the production management system to meet the needs of a specific task, thus achieving interoperability.
III. System Design Objectives
The design goals of the SCADA system for the gas dispatch center are as follows:
▲Collect and store all parameters from each station and database, and aggregate them to the dispatch center platform;
▲Monitoring of key parameters and main process screens at each station/warehouse;
▲Statistical analysis of key parameters of each station and warehouse;
▲Trend charts, pie charts, and bar charts showing the main parameters of each station's database;
▲Daily, monthly, quarterly, and annual reports of key parameters for each station/database;
▲The equipment supports remote control, allowing remote customers to view on-site data in real time.
IV. System Architecture
The system boasts excellent scalability and extensibility, enabling seamless and low-cost integration of newly added databases. Its web publishing functionality allows users to access the system anytime, anywhere, via user authentication.
To improve system stability, reliability, and availability, redundant networks are constructed in the central system to enhance the stability of underlying communications. Redundant communication servers, database servers, and application servers improve system reliability, while network firewalls and virus firewalls enhance the system's resilience. A network backup device (NAS) is installed to significantly reduce data loss caused by unexpected incidents.
After analyzing the on-site conditions of the entire system network topology, the following hybrid mode structure was selected, and the overall topology diagram is shown below:
Figure 1 System Architecture Diagram
In the construction of the system, in accordance with the principle of reducing system communication costs, for branch offices that have already been connected to the group's private network, it is advisable to consider transmitting the data of each branch station within the branch office to the group headquarters through the group's private network. This can reduce the operating costs incurred by applying for multiple ADSL links. However, it should be noted that if the group's private network is used to transmit data, the bandwidth of data transmission should be guaranteed as much as possible.
Because the existing monitoring system platforms of each branch office are different, in order to facilitate the standardization of data communication formats and ensure data security, one ForceControl Technology industrial data acquisition and communication gateway pFieldComm and one ForceControl Technology industrial security protection and isolation device pSafetyLink are installed and configured in each branch office system. Data can be collected from each branch station to the communication gateway pFieldComm via various bus methods, and then transmitted in real time to the security protection and isolation device pSafetyLink via another network port. Upon receiving the data packets, the device parses the packets, strips the TCP/IP protocol, and transmits the raw data unidirectionally to the other side of the device.
ForceControl Technology's pSafetyLink device encrypts and compresses remote data, then transmits the encrypted and compressed data packets to a server in a remote dispatch center via the Internet. Utilizing the device's dual-system, unidirectional isolation transmission function, viruses and cyberattacks are completely isolated from the external network, maximizing the security and reliable operation of the production system.
4.1. Software System Architecture
The gas dispatch center uses the pSpace platform software, an enterprise-level real-time historical database from Likong Technology, to archive, store, and process the data.
The pSpace platform offers a mature and advanced production management solution for manufacturing enterprises. Designed entirely according to a hierarchical and modular approach, the software abstracts and refines the entire system based on the characteristics and needs of manufacturing companies. It is designed and expanded around data as the main thread, with various drivers at the bottom layer extracting different types of production data to build a unified database platform for enterprise production information. Furthermore, it uses industry application characteristics as a model, combined with a powerful computing engine to build application function modules, culminating in a unified presentation at the top layer to serve the enterprise. The entire system can be summarized as follows: distributed data acquisition, centralized data storage, distributed modular application, and unified information display.
Figure 2 Software System Architecture Diagram
V. System Function Summary
5.1. Real-time monitoring screen display
Using the screen configuration tools of ForceControl's configuration software, users can quickly and easily develop customized graphical view applications. These applications can display real-time process data, providing timely information on temperature, pressure, flow rate, leak alarms, and other real-time data to relevant personnel at the gas dispatch center.
Figure 3 Real-time screen display
Figure 4 Real-time video display—production data
5.2. Data reporting and curve analysis functions
The gas dispatch center's SCADA system can automatically generate daily, monthly, and annual reports. Managers can understand the past status of the pipeline network and analyze future trends through trend analysis, reports, and historical playback. The system also has the function of generating special reports such as time-of-use reports, allowing for arbitrary combinations of user measurement trends, cumulative measurement parameters, fault periods, and other trend records, which can be printed out.
5.3. Alarm events and security management functions
The system can display and record various alarm information of the local flow measurement system in real time, such as flow/pressure exceeding limits, abnormal instrument power supply, abnormal valve operation, communication failure and other alarm information.
Furthermore, the gas dispatch center system has strict access control and operation tracking functions, recording all user operations and providing evidence and means for investigating system security issues. To ensure the security and reliability of system data acquisition and control, this solution adopts a dual-machine hot standby and dual-network redundancy configuration for SCADA operator stations.
5.4. Enterprise Information Portal Function
To meet the requirements of modern enterprise informatization, the ForceControl software platform can provide the enterprise's production process system, data browsing system, data query system, and data analysis system via the web.
The web-based configuration, operation, and management methods significantly reduce enterprise management and maintenance costs. Operators do not need high-level programming skills to customize and modify the pages and functions of the pSpaceWEB system. Username and password authentication ensures system security.
VI. Conclusion
The informatization of the gas dispatch center actively responds to the national development strategy of vigorously promoting the deep integration of informatization and industrialization, following a new path of industrialization with Chinese characteristics, and promoting the transformation of economic development patterns and industrial upgrading. The entire system combines advanced computer technology, network communication technology, and automated control technology, which can improve work efficiency, reduce costs, and provide strong support for the unified dispatch and management of the gas pipeline network.
