Abstract: The power monitoring system of Chongqing Johnson Controls Battery Co., Ltd. is introduced. Intelligent power meters are used to collect various electrical parameters and switch signals at the distribution site. The system adopts on-site local networking method. After networking, it communicates via the field bus and transmits it to the background. The Acrel-2000 power monitoring system realizes the real-time monitoring of power distribution circuit substations in substations.
Â
Keywords: Chongqing Jiangsen; substation; smart power meter; Acrel-2000; power monitoring system;
Â
0 Â Â Overview
Johnson Controls Inc., a Fortune 500 company, plans to establish an independent legal entity in Chongqing Fuling District, Chongqing Johnson Controls Battery Co., Ltd. (hereinafter referred to as Chongqing Johnson), to produce high-capacity, fully sealed, maintenance-free lead-acid batteries and other high-performance power batteries. The project will be completed and put into operation in June 2012. In 2013, it will have a capacity of 6 million/year.
This project is Chongqing Jiangsen Power Monitoring System. According to the requirements of distribution system management, a high-voltage room, a generator room, and five low-voltage substations of Chongqing Johnson (substation 1#, substation 2#, substation 3#, substation 4) are required. the high-voltage cabinet in substation # 5), with the low-pressure electric power line monitoring to ensure the electrical safety, reliable and efficient.
Acrel-2000 low-voltage intelligent power distribution system takes full advantage of the latest developments in modern electronic technology, computer technology, network technology and fieldbus technology, and conducts distributed data acquisition and centralized monitoring and management of the power distribution system. The secondary equipment of the distribution system is networked. Through the computer and the communication network, the field devices of the decentralized power distribution station are connected into an organic whole, and the remote monitoring and centralized management of the power grid operation is realized.
Â
Â
1 System Structure Description
The monitoring system mainly realizes a high-voltage room, a generator room, and five low-voltage substations of Chongqing Johnson (1# substation, 2# substation, 3# substation, 4# substation, and 5# substation. 10/0.4kV power distribution system for power supply monitoring and management; high-voltage cabinets in the basement one-story high-voltage room, power distribution screens for diesel generator rooms, and low-voltage inlet cabinets for five low-voltage substation transformers , contact cabinets, feeder cabinets for remote real-time monitoring and power management. The system has a total of 212 instruments (including 12 ACR230ELHs, 188 ACR220ELs, and 12 ABBs), divided into 12 buses, including 1 bus in the high-voltage room, 1 bus in the generator room, and 2 substations in the 1# substation . Bus, using shielded twisted pair directly to the monitoring room; 2#, 3# substation adopts 4 buses, which is set up in the communication collection box of 2# substation and uploaded to the monitoring duty room through the optical fiber; 4# The 5# substation adopts 4 buses, which are set up in the communication collection box of the 4# substation and uploaded to the monitoring duty room through the optical fiber. Finally, the data is unified and summarized to the monitoring host through the industrial switch .
The monitoring system adopts a hierarchical distributed structure, ie station control layer, communication layer and bay layer; as shown in Figure (1):
Figure (1) Network topology
Â
Interval equipment layer mainly includes: multi-function network power meter, switch quantity, analog acquisition module and intelligent circuit breaker. These devices are corresponding to the corresponding primary equipment installed in the electrical cabinet, these devices are used RS485 communication interface, through the on-site MODBUS bus network communication, data acquisition on the spot.
The main network communication layer is: a communication server. The main function of the communication server is to collect the scattered data at the site collection device, and transmit it to the station control layer at the same time, to complete the data exchange between the field layer and the station control layer.
Station control management: equipped with high-performance industrial computers, monitors, UPS power supplies, printers, alarm buzzer and other equipment. The monitoring system is installed on the computer to collect and display the operating status of the field equipment and display it to the user in the form of human-computer interaction.
The above network instruments use RS485 interface and MODBUS-
RTU communication protocol, RS485 uses shielded cable transmission, generally use two connections, the connection is simple and convenient; the communication interface is half-duplex communication that both parties can receive and send data, but can only send or receive data at the same time. The maximum data transfer rate is 10Mbps.
The RS485 interface is a combination of balanced drivers and differential receivers. It has enhanced noise immunity and allows up to 32 devices to be connected on the bus. The maximum transmission distance is 1.2 km.
2 main functions of the power monitoring system
2.1 Data Acquisition and Processing
Data acquisition is the basis of power distribution monitoring. Data collection is mainly accomplished by the underlying multi-function network instrumentation, realizing local real-time display of remote data. The signals that need to be collected include: three-phase voltage U, three-phase current I, frequency Hz, power P, power factor COSφ, power Epi, and remote device operating status.
The data processing mainly displays the electrical parameters collected according to requirements in real time and accurately to the user, so as to meet the requirements of automation and intelligence of the power distribution monitoring, and store the collected data in the database for user query.
2.2 Human-computer interaction
The system provides simple, easy to use, and good user interface. Using the Chinese interface, the CAD graphic shows the electrical main wiring diagram of the low voltage distribution system, shows the status of the distribution system equipment and the corresponding real-time operating parameters, the screen timing switching tour; dynamic refresh of the screen real-time; analog display; switch display; continuous Record display and so on.
2.3 Diachronic events
The duration event viewing interface provides users with easy and friendly human-computer interaction by viewing the fault records, signal records, operation records, and over-limit recordings that have occurred. You can view the platform through historical events. You can easily locate the fault according to your requirements and query conditions. The historical events that you want to view provide you with good software support for the overall system operation.
2.4 Database Establishment and Query
It mainly completes the remote measurement and remote signal acquisition, and establishes a database to generate reports regularly for users to query and print.
2.5 User Rights Management
For different levels of users, different permission groups are set to prevent the losses caused by human misoperation to production and life, and to realize the safe and reliable operation of the distribution system. You can use user management to perform user login, user logout, password change, and add/delete operations to facilitate user modification of accounts and permissions.
2.6 Running load curve
The load trend curve function is mainly responsible for regularly collecting incoming lines and important loop current and power load parameters, and automatically generating running load trend curves to facilitate users to know the operating load status of the equipment in a timely manner. Click the corresponding button or menu item of the screen to complete the switching of the corresponding function; you can view the real-time trend curve or historical trend line; you can perform operations such as pan, zoom, and range conversion on the selected curve to help the user enter the line trend.
Potential analysis and fault recall provide intuitive and convenient software support for analyzing the operating status of the entire system.
2.7 Remote Report Query
The main function of the report management program is to design the report style according to the needs of the user, and the data processed in the system is filtered, combined and statistically generated to generate the report data required by the user. This program can also be based on the needs of users of the report file to save, print or summon save, print mode. At the same time, this program also provides users with management functions for generated report files.
The report has the functions of freely setting the query time to realize daily, monthly, and annual energy statistics, data export, and report printing.
3 case analysis
Chongqing Jiangsen Power Monitoring System is divided into 1 high voltage room, 1 generator room and 5 low voltage substations (1# substation, 2# substation, 3# substation, 4# substation, 5# substation 10/0.4kV power distribution system for power supply monitoring and management; high-voltage cabinets in the basement one-story high-voltage room, power distribution screens for diesel generator rooms, and low-voltage inlet cabinets for five low-voltage substation transformers , contact cabinets, feeder cabinets for remote real-time monitoring and power management. The system has a total of 212 instruments (including 12 ACR230ELHs, 188 ACR220ELs, and 12 ABBs), divided into 12 buses, including 1 bus in the high-voltage room, 1 bus in the generator room, and 2 substations in the 1# substation . Bus, using shielded twisted pair directly to the monitoring room; 2#, 3# substation adopts 4 buses, which is set up in the communication collection box of 2# substation and uploaded to the monitoring duty room through the optical fiber; 4# The 5# substation adopts 4 buses, which are set up in the communication collection box of the 4# substation and uploaded to the monitoring duty room through the optical fiber. Finally, the data is unified and summarized to the monitoring host through the industrial switch .
The incoming circuit uses ACR230ELH multi-function harmonic instrument, which is a network power meter designed for the power monitoring needs of power systems, industrial and mining enterprises, public facilities, and intelligent buildings. It can measure all conventional power parameters such as: three-phase voltage, Current, active power, reactive power, power factor, frequency, active power, reactive power, and voltage-current monitoring of 2-31 harmonic components and other electrical parameters. And this instrument has 4 photoelectric isolation digital input contacts and 2 relay control output contacts. These contacts can be used with intelligent circuit breakers to achieve remote signaling and remote operation of the circuit breaker. The series of network power meters are mainly used in substation automation, distribution network automation, residential power monitoring, industrial automation, energy management systems and intelligent buildings.
The important distribution circuit adopts ACR220EL series network power meter. The meter mainly measures all conventional power parameters such as: three-phase voltage, current, active power, reactive power, power factor, frequency, active power, and reactive power.
The high-pressure side real-time screen is shown in Fig. ( 2). It is the main monitoring screen of the system. It mainly monitors the running status of the high-pressure loop in real time. Red represents closing, and green represents breaking. In the high-voltage system diagram, you can intuitively see the operating parameters and status of each high-voltage incoming and outgoing line, you can see all the conventional power parameters of the transformer outlet side, such as: three-phase voltage, current, active power, reactive power, Power factor, frequency, active power and transformer temperature, see Figure (3).
Figure (2) High-pressure system diagram
Figure (3) Transformer temperature controller monitoring
Â
The secondary diagram of low-voltage power distribution is shown in figure ( 4). The main function of the power telemetry is to monitor the electrical parameters of the operating equipment, including: three-phase voltage, current, power, power factor, electrical energy, frequency and other electrical parameters and distribution loops. Three-phase current; remote signal function to display the operating status of field devices, mainly including: switching of the switch, closing operation status and communication failure alarm; when the circuit breaker is dislocated, it will send an alarm signal to remind the user to deal with the fault in time.
Figure (4) Secondary diagram of low voltage distribution
Â
The remote signaling and telemetry alarm functions mainly complete the monitoring of the switching operation status and load incoming line of the low-voltage outlet loops, and indicate the specific alarm position and audible alarm to the switch displacement and load over-limit pop-up alarm interface to remind the on-duty personnel to deal with it in time. The load limit can be set freely under the corresponding authority. With history query function. See Figure ( 5).
Figure (5) Real-time alarm information
Â
The parameter reading function mainly inquires into the electrical parameters of the low-voltage outlet circuit. Supports electrical parameter query at any time, with functions such as data export and report printing. The report queries the electrical parameters of the low-voltage loops for the four transformer substations of the two substations , mainly including: three-phase current, active power, active power, and transformer temperature. The names of the loops in this report are associated with the database to facilitate the user to modify the loop name. See Figure (6).
Figure (6) Parameter meter reading
Â
The electricity consumption report function can select the time period to inquire, supports the accumulated electricity inquiry at any time, and has the functions of data export and report printing. Provide accurate and reliable power report for duty personnel. The names of the loops in this report are associated with the database to facilitate the user to modify the loop name. As shown in the figure below, the precise power consumption of each distribution circuit in a certain period of time in the fitness center can be displayed. The user can print the report directly, and can save it in EXCEL format to another location. See Figure (7).
Figure (7) Energy Daily Report
Â
The schematic diagram of the system communication structure mainly shows the networking structure of the system. The system adopts a hierarchical distributed structure and simultaneously monitors the communication status of the equipment at the bay level. Green indicates normal communication and red indicates communication failure. See Figure ( 8).
Figure (8) System Communication Structure
The load trend curve interface allows you to visually check the load operation of the loop. View real-time and historical trend curves, click the corresponding button or menu item to complete the switching of corresponding functions; help the user to enter the trend analysis and fault recall, with curve printing function. Provides intuitive and convenient software support for analyzing the health of the entire system. See Figure ( 9).
Graph (9) Trend Graph
Â
4 Conclusion
The intelligent power monitoring system has become an inevitable choice for large-scale multi-substation users in key project projects, landmark buildings, and large-scale public facilities throughout the country. The application of the Acrel-2000 power monitoring system introduced in Chongqing in this paper can achieve The real-time monitoring of substation high and low voltage distribution circuits can not only show the power status of the circuit, but also have network communication functions. It can be combined with serial servers and computers to form a power monitoring system. The system analyzes and processes the collected data, displays the running status of each distribution circuit in the substation in real time, has a pop-up alarm dialog box and voice prompts for the closing and closing of the load, and generates various energy reports and analysis curves. Graphics, etc., to facilitate remote meter reading and analysis, research. The system is safe, reliable and stable. It provides real and reliable basis for users of substations to solve electricity problems and has achieved good social benefits. [2]
references:
[1]. Cheng cause any week. Electricity measuring digital instruments Principles and Applications Guide [M]. Beijing. China Electric Power Press. 2007.4
[2]. Zhou Zhongzhong . Smart grid customer end power monitoring and power management system product selection and solution [M]. Beijing . Machinery Industry Press . 2011.10