Abstract: With the continuous development and progress of science and technology, the electricity consumption of large public places is increasing day by day. How to manage electricity consumption more conveniently and ensure the safe and stable operation of the power grid is of great concern. At the same time, intelligent circuit control is becoming an important aspect of intelligent control. Automation control of substations is a measure to improve the safety, reliability, and stability of substation operation, reduce operation and maintenance costs, improve economic efficiency, and provide users with high-quality power services. Intelligent circuit control can realize diverse control combinations to meet the needs of different occasions. This paper briefly introduces the application of configuration software in power management and intelligent circuit control in substations based on the Acrel-3000 power monitoring software, ACR320ELK network power meter, and ARTU-J16 control unit monitoring and intelligent management system. This system designs and implements a distributed acquisition and centralized control management system, realizing the function of unmanned management of the substation by the microcomputer, eliminating the tedious on-site operation of circuit breakers by on-duty personnel, improving power supply quality and management level, and has the advantages of simplicity, practicality, and low investment.
Keywords: power monitoring software, power meters, power management
Overview
The project comprises two power distribution rooms (one main distribution room and one generator room) and a venue lighting control room, providing power for the National Stadium's offices, lighting, stadium lighting, air conditioning, and other needs. All circuits are equipped with ACR320ELK network power meters, capable of measuring electrical parameters such as voltage, current, and power in the distribution rooms. Remote operation of each circuit can be achieved via electric operating mechanisms. Based on customer requirements, the designed Acrel-3000 power monitoring system not only enables remote monitoring and centralized management of each power distribution circuit but also allows for remote operation of circuit opening and closing; and it can provide tiered intelligent control of venue lighting according to different competition specifications.
System Analysis
The monitoring scope of this system is as follows: Before project commencement, Party A must provide the primary system diagram, floor plan, and secondary system diagram of the power distribution system for Party B's design reference. Party B will complete the system design according to Party A's actual needs and the functions of the intelligent components. The main functions include: primary wiring diagram interface display; remote measurement of electrical parameters and alarm for exceeding electrical parameter limits; remote signaling of switch status, tripping alarm, and remote opening and closing control of circuit breakers (this function requires the circuit breakers to be equipped with electric operating mechanisms on site); event logging, power management reports (generating daily, monthly, and annual reports, etc.); system operation anomaly monitoring; fault alarms and operation records; report query and printing; real-time and historical system load curves; user access control, etc. Party B may make feasible modifications to the actual detailed functions according to Party A's usage habits and needs.
The entire system adopts a network-distributed architecture. The monitoring host is located in the power distribution room, and various instruments in the generator room are also connected to the entire monitoring system via twisted-pair cables. The power distribution cabinet in the power distribution room is equipped with more than 120 circuits of our company's ACR320ELK network power meters. The system uses an open communication protocol and connects to the power distribution system through a fieldbus to realize data communication and control functions.
System Structure
This system adopts a hierarchical distributed computer network structure, namely the interval layer, communication layer, and station control layer, as shown in the figure below:
The main equipment in the mezzanine includes: multi-functional network power meters, digital and analog signal acquisition modules, and intelligent circuit breakers. These devices are installed in electrical cabinets corresponding to the primary equipment. All devices use RS485 communication interfaces and communicate via a field MODBUS bus network to achieve on-site data acquisition.
The middle layer mainly consists of a communication server, whose main function is to centrally collect data from the scattered field acquisition devices and transmit it to the station control layer, thus completing the data interaction between the field layer and the station control layer.
Station control layer: Equipped with high-performance industrial computers, monitors, UPS power supplies, printers, alarm buzzers, and other equipment. The monitoring system is installed on the computer, centrally collecting and displaying the operating status of field equipment, presenting it to users in a human-machine interactive format. Users can also send commands to field equipment via system software to achieve remote control functionality.
All the above network instruments use RS485 interfaces and the MODBUS-RTU communication protocol. RS485 uses shielded wires for transmission, typically requiring only two wires for simple and convenient wiring. The communication interface is half-duplex, meaning both parties can send and receive data, but only one can send or receive data at a time. The maximum data transmission rate is 10Mbps. The RS-485 interface uses a combination of balanced drivers and differential receivers, enhancing noise immunity. Up to 32 devices can be connected on the bus, with a maximum transmission distance of 1.2km.
Main functions of the system
I. Data Acquisition and Processing Data acquisition is the foundation of power distribution monitoring. The signals that need to be acquired include: three-phase voltage U, three-phase current I, frequency Hz, active power P, reactive power Q, electricity consumption EPI, and switching quantities.
Data processing mainly involves displaying the collected electrical parameters to users in real time and accurately, in order to achieve the automation and intelligence requirements of power distribution monitoring. At the same time, the collected data is stored in a database for users to query.
II. Human-Computer Interaction This power monitoring system provides a simple, easy-to-use, and user-friendly interface. It displays the primary electrical wiring diagram of the low-voltage power distribution system entirely in English, shows the status of power distribution system equipment and corresponding real-time operating parameters, and features timed screen rotation, real-time dynamic screen refresh, and analog quantity display.
The venue lighting control system, designed according to the design institute's requirements and taking into account the physical characteristics of the lighting, uses intelligent scripts to switch and control modes for different competition requirements. This not only meets the design requirements but also effectively extends the equipment's lifespan by incorporating the physical characteristics of the lighting.
III. Fault Alarm and Accident Recall: When an operational fault occurs in the power distribution system, an audible and visual alarm will be issued in a timely manner to prompt users to respond to the faulty circuit. At the same time, the time and location of the event will be automatically recorded so that users can query and recall the cause of the fault.
IV. The electricity cost management system automatically performs daily, monthly, and yearly electricity statistics, providing electricity statistics functions and generating daily, monthly, and yearly reports.
V. User Access Management: The system allows for the addition and deletion of software users and the setting of user permissions according to the client's requirements. Different permission groups can be set for different user levels to prevent losses to production and daily life due to human error, ensuring the safe and reliable operation of the power distribution system.
VI. The system periodically collects current and load parameters of incoming lines and important circuits, and automatically generates operating load trend curves, which allows users to understand the operating load status of the equipment in a timely manner, display the current and power data of important circuits in real time, and query historical current and power data.
7. Alarm Setting Voltage Upper Limit Setting: Upper limits can be set for high voltage incoming line voltage, low voltage phase voltage, and line voltage respectively. When the real-time data exceeds the upper limit, the data will change from black to red, and a record will be left in both real-time alarm and historical alarm.
Load limit setting: Upper limits can be set for the high-voltage incoming load and the load of each transformer. When real-time data exceeds the upper limit, the data changes from black to red, and a record is left in both real-time alarms and historical alarms. (See figure)
This makes management much easier.
System Features
With fewer communication cable connections, the screen display is intuitive, data refresh is fast, and the operating status of field equipment is reflected in a timely manner. At the same time, the system is simple to operate and convenient for users. Various functions can be flexibly changed according to user needs. The system design is quick and easy, and software modification is not complicated.
Conclusion
This article describes the characteristics, structure, and functions of a stadium's integrated automated control system. This system is part of a large-scale systems engineering project, and many technical challenges remain to be overcome in achieving automated control of stadium power monitoring. The author believes that in the not-too-distant future, stadium automated control systems with convenient management capabilities will see further development.
References
[1] Ren Zhicheng and Zhou Zhong, eds. Principles and Application Guide of Digital Instruments for Power Measurement, China Electric Power Press, 2007.4
[2] Zhu Liquan. Analysis of Intelligent Management System for Power Distribution System. Intelligent Building Electrical Technology, Vol. 1, No. 4, 2007.
[3] Wang Zhensheng's analysis of "Computer Monitoring System for Substations", Intelligent Building Electrical Technology, Vol. 5, No. 3, 2006
For more detailed information, please contact:
Contact person for Jiangsu Ankerui Electric Manufacturing Co., Ltd.: Xu Yuli, Tel: 13771584106
QQ: 1759867226
MSN: [email protected]
Telephone: 0510-86179968
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Email: [email protected]
Homepage: http://www.jyacrel.cn/
Address: No. 5, Dongmeng Road, Nanzha Town, Jiangyin City, Jiangsu Province
