Abstract: Power transmission, distribution, protection, and control are prerequisites for power application and fundamental objectives of electrical construction, especially for the Asian Games opening and closing ceremony venues, which require stable and uninterrupted power supply. Therefore, the Asian Games Organizing Committee exercised utmost caution in selecting electrical equipment and suppliers. Shanghai Acrel Electric Co., Ltd.'s Acrel3000 power monitoring system truly stood out in this context, becoming a member of the Asian Games power supply guarantee system.
1 Overview
Haixinsha Island is located on a sandbar in the Pearl River in Guangzhou, on the main northern channel of the Pearl River. The opening ceremony of the 16th Asian Games in Guangzhou in 2010 and the closing ceremony two weeks later were held here.
The power supply for the entire island consisted of two parts: on-site generators and power from the Guangzhou Power Supply Bureau. All power distribution facilities were located in the underground space beneath the stage, comprising four distribution areas: (1#) integrated substation, (2#) integrated substation, underground space (3#) integrated substation, and (4#) integrated substation. Each substation included a 10KV high-voltage distribution cabinet, a DC power supply unit, a 0.4KV low-voltage distribution cabinet, generators, and transformers. On the night of the Asian Games opening and closing ceremonies, all important circuits related to performances, fountains, and sound systems were powered by on-site generators, while the remaining stands and lighting were powered by the Guangzhou Power Supply Bureau.
As the venue for the opening and closing ceremonies of the intercontinental games, the power supply and distribution system requires extremely high stability and safety. Therefore, a power monitoring system workstation is set up in each integrated substation area to monitor the operating status of all equipment in that substation, provide early warnings, analyze faults, generate statistical outputs, and implement automatic control. A central control room is located in the grandstand equipment monitoring center, housing the system server and main management workstation. All power parameters from the substations are transmitted to the central control room via fiber optic cable. Simultaneously, a power monitoring system workstation is set up on the 10th floor of the Guangzhou Power Supply Bureau, with data transmitted to the power supply bureau's dispatch center via the network company's local area network and the Guangdong Province 104 protocol. This multi-faceted, comprehensive, and in-depth approach ensures the flawless power supply for the Asian Games.
In line with the above requirements, the Acrel-3000 power monitoring system makes full use of the latest developments in modern electronic technology, computer technology, computer network technology, and fieldbus technology to carry out distributed data collection and centralized monitoring and management of the power supply and distribution system throughout the island.
2. System Network 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:
Figure 1
As the foundation of the entire power distribution system, the main equipment in the field bay includes: multi-functional network power meters, leakage current monitoring devices, microcomputer-based integrated protection devices, DC power supply systems, and transformer temperature controllers. These devices are installed in the high and low voltage electrical cabinets, temperature control boxes, and DC power supply cabinets, respectively, corresponding to the primary equipment. The multi-functional network meters, leakage current monitoring devices, microcomputer-based integrated protection devices, and transformer temperature controllers use RS485 communication interfaces and communicate via a field MODBUS bus network. The DC power supply system uses a 232 interface and acquires data on-site through the CDT communication protocol.
The communication network layer mainly consists of communication servers, optical transceivers, and switches. Its main function is to centrally collect data from scattered field acquisition devices and simultaneously transmit it to the station control layer, thus completing data exchange 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 on-site equipment, and presenting it to the user in a human-machine interactive format.
All the above network instruments use RS485 and RS232 interfaces via MODBUS-RTU and CDT communication protocols. RS485 uses shielded cable transmission, typically employing 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.
Data is transmitted to the central server via the local area network in the form of serial port protocol data forwarding at the station control layer. At the central server, it is transmitted to the Guangzhou Power Supply Bureau Dispatch Center via high-speed Ethernet using the 104 protocol.
3. Main functions of the system
3.1 Data Acquisition and Processing Data acquisition is the foundation of power distribution monitoring. It is primarily accomplished by the underlying measurement and control devices, enabling real-time local display of remote data. The signals to be acquired include: three-phase voltage U, three-phase current I, frequency Hz, power P, power factor COSφ, electricity consumption Ep, remote equipment operating status, temperature, and other data.
Data processing primarily involves displaying the collected electrical parameters to users in real-time and accurately, achieving the automation and intelligence requirements of power distribution monitoring. Simultaneously, the collected data is stored in a database for user query and analysis. This avoids the need for the operations support team to directly inspect the power distribution system's operating status in the distribution room, ensuring that faults are detected and resolved in the shortest possible time.
3.2 The human-machine interface displays the primary wiring diagram of the high and low voltage power distribution system through a fully Chinese interface and CAD graphics. It displays the current operating information of each circuit's equipment and updates it in real time. The current circuit's operating status is also displayed through coloring, as shown in the figure below:
Figure 2
3.3 Fault Alarm and Accident Tracking When an operational fault occurs in the power distribution system, an audible and visual alarm will be issued promptly to alert users to respond to the faulty circuit. Simultaneously, the time and location of the event will be automatically recorded for users to query and track the cause of the fault. The record is shown in the following figure:
Figure 3
The diagram shows that the field circuit generated an open/closed position alarm message.
3.4 User access control allows for the addition and removal of software users and the setting of user permissions according to user requirements. Different permission groups can be set for different user levels to prevent losses to production and daily life due to human error, and to ensure the safe and reliable operation of the power distribution system.
3.5 The system periodically collects current 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 harmonic data (2nd to 31st harmonics) of important circuits in real time, and query historical harmonic data, etc.
Figure 4
Due to the extremely high safety requirements for the power distribution system on the night of the opening ceremony, on-site power generation was adopted for critical circuits to ensure the safe and stable operation of the power distribution system. In Figure 4, the bright red curve represents the power supply trend curve of the Guangzhou Power Supply Bureau, the purple part represents the power generation trend of the on-site generators, and the green curve represents the current total power operation trend. The real-time trend curves can help on-duty personnel closely monitor the current load operation status.
3.6 Database establishment and querying: This mainly involves the timed collection of telemetry and teleindication data, the establishment of a database, and the periodic generation of reports for users to query and print.
3.7 Data forwarding function: All operational data is transmitted via Ethernet from the Haixinsha on-site duty room to the Guangzhou Power Supply Bureau Dispatch Center using the 104 protocol, and is centrally monitored and managed by the municipal power supply department.
4 System Features
The system's hardware and software are all modular, and the hardware is fully intelligent. The hardware and software design adheres to industrial-grade standards, ensuring extremely high reliability. The entire system's intelligent control terminal and remote intelligent communication controller are composed entirely of 16-bit microcomputers. This distributed control system offers high speed, excellent real-time performance, and reliable communication. The intelligent control terminal has its own CPU, resulting in short data acquisition cycles, strong real-time performance, and high system redundancy. Each subsystem operates independently without interfering with others. Furthermore, the modular design of both the subsystems and the overall system further enhances security and reliability.
5. Summary
This article introduces the overall structure and functions of the power monitoring system for the opening and closing ceremonies of the Guangzhou Asian Games. After its investment and operation, the system has withstood the test of multiple opening ceremony rehearsals and successfully demonstrated its effectiveness on the night of the opening and closing ceremonies. Analysis of data from these rehearsals yielded the optimal power generation load, ensuring both power supply reliability and cost savings, thus responding to the call for a cost-effective Asian Games.
References:
[1] Ren Zhicheng, Zhou Zhong. Principles and Application Guide of Digital Instruments for Power Measurement [M]. Beijing: China Electric Power Press. 2007. 4
For more detailed information, please contact:
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