Summary:In view of the current research status of industrial power mode, this paper expounds the design of power management system based on modern Ethernet. The system realizes the remote real-time monitoring and management of electric energy, and the system supports remote access of a variety of terminal equipment, establishes a real-time human-machine interface management platform, and realizes the modern management mode of electric energy. It improves the management efficiency and power supply efficiency of power supply enterprises, and provides a new idea for remote monitoring of large power grids across regions.
Keywords:electrical energy management; Industrial Ethernet; energy monitoring; Hmi.
0 Introduction. With the development of the power grid and the introduction of relevant policies, the management of electricity consumption has gradually realized the system of one meter per household and meter reading to the household. But the problem that comes with it is the copying and management of a large amount of electricity consumption data. At the same time, the variety of customer groups that use electricity determines the requirements for high-quality power supply. Due to the defects of its own structure, the traditional power management system can no longer meet the electricity demand of the current society in terms of effectiveness, real-time controllability, accuracy and application characteristics, and will cause a waste of power resources and human resources. Therefore, the power management door needs to accelerate the popularization of new power management systems.
With the rapid development of Internet technology, modern science and technology will gradually replace traditional power measurement tools. With the continuous emergence of various modern intelligent products, in terms of power management, the research on managing power systems through industrial Ethernet has gradually become the main research mainstream of power systems. The remote control of electric energy adopts remote management and control of electric energy through man-machine interface, and carries out high-speed and efficient analysis, calculation and control of the collected data, thereby saving a lot of human resources and improving management efficiency. The electric energy network monitoring system based on industrial Ethernet is the development trend of the country's centralized monitoring of power consumption and rational use of electric energy in the future.
In view of the current market demand for power quality, the power management structure of Ethernet is discussed, and the key technologies used in the system are described. The system realizes the functions of remote monitoring of electric energy and classified data collection, data analysis, protocol conversion, data encryption protection and storage in the process of data transmission. Thus, the design of the power management system based on wireless Ethernet is realized.
1. System structure.
In view of the current status of the power management system, the power management system proposed in this paper is a three-layer power management system based on industrial Ethernet. The structure diagram of the power management system is shown in Figure 1. The main function of the system is to realize the real-time collection and analysis of on-site data, and remote control and management of electric energy through industrial Ethernet.
Figure 1 Structure diagram of the power management system.
The first-level architecture of the system is the base station on-site acquisition network, and the network diagram is shown in Figure 2 for the local base station on-site acquisition network diagram. The on-site collection network of the base station realizes the classified collection of information such as on-site power consumption data of the base station, and realizes data analysis, protocol conversion, data encryption protection and storage in the process of data transmission. The data is transmitted to the secondary data mining collection center in the form of a link structure.
Figure 2 On-site collection network diagram of local base stations.
The mid-end data aggregation network center is the *2 architecture of the system, which is mainly responsible for collecting the data sent from the network collected from each base station on site, and caching and summarizing the electricity consumption data. After that, according to the standards set by the upper-level center, the data is classified and uploaded, and uploaded to the upper-level in different time periods.
The latter layer of architecture is the terminal data center, that is, the provincial data department monitoring platform. The terminal data center will build a software platform for monitoring the system, analyze and manage the data information collected from the receiving province, classify it and store it, and back up the data regularly. Statistics are performed on the database based on the backup time and the content of data analysis and management, and various types of statistical reports are generated. According to the content of the report to formulate the management process system, the standardization of energy-saving data can be realized, making the power management more humane.
This paper mainly analyzes and studies the Ethernet monitoring module and PLC main control module of the power management system. Among them, the power management system involves many fields such as single-chip microcomputer technology, power electronics technology and communication technology.
2. Design of the control system.
In the power management system, the Ethernet-based monitoring module can be roughly divided into five modules, namely the PLC main control module, the data acquisition module, the loop on-off control module, the system power monitoring module, and the human-machine interface module.
2.1PLC main control module.
Figure 3 shows the hardware structure of the system. The system hardware is composed of three parts: the control end, the controlled end, and the controlled object. The power management system in this paper is based on a programmable logic controller as the control core of the system, and the PLC main control module has a plurality of data acquisition ports, and there are more than 100 collection points on each port, so that the main control template can be distributed in each monitoring area; Through industrial Ethernet, each main control template can be interconnected to form a control network. The implementation process is as follows: each monitoring area collects data information through the collection point, the PLC main control module integrates and calculates the collected information, feeds back the processed data to the user and classifies and stores it, so that the user can view and call, the archived data can be exchanged through Ethernet, and the classified data will be sent to the control center. The staff of the power management system can use the PC to monitor the user's electricity consumption in real time, and can use the PC to send remote control instructions. For example, power failure and emergency repair, power failure punishment for illegal users, etc.
In addition, the main control module and the system electric energy monitoring module can be used together to achieve the purpose of collecting electrical signals, and to realize the on-off power control of the line.
Figure 3 System hardware architecture.
2.2. Data acquisition module.
An indispensable link in an Ethernet-based power management system is the data acquisition module. The signal received by the acquisition port of the data acquisition module is a voltage and current signal, and a current and voltage transformer is used in this system to collect the electrical signal. Figure 4 shows the structure of the acquisition terminal. The signal is transmitted to the data processing center through the voltage and current transformer coupler, and because the large current and voltage signals are not easy to transmit, it needs to be scaled down to small signals that are easy to measure, and the signal will pass through the power monitoring module of the system first, and then transmit to the control center.
Figure 4 Block diagram of the acquisition terminal.
2.3-loop on-off control module.
The loop on-off control module is coordinated by the solid-state relay and the PLC main control module to realize the function of loop on-off control. Solid state relay is a kind of electronic switch with isolation function without contact, it is connected to the input end of the user's power supply equipment, when the control center feeds back the user's excess power information, the control center will send a power-off notification command to the PLC main control module, and the main control module cuts off the power supply through the solid state relay. Therefore, the loop on-off control is to control the on-off state of each power supply line through a solid-state relay.
2.4. System power monitoring module.
The working principle diagram of the system power monitoring module is shown in Figure 5, and the function of the system power monitoring module is to further process the signal collected by the data acquisition module, and the input signal of the analog sensor and the switching sensor will be measured, compared and analyzed, and the safety signal that the main control module can identify is output.
The process realized by the electric energy monitoring module is to filter the current and voltage signals collected by the data acquisition module respectively, in order to prevent the high-frequency signal from interfering with the measured electrical signal, the high-frequency interference signal must be processed at first, and the processing method is to add a low-pass filter in the circuit, and the signal * of high-frequency interference is filtered out and amplified with an operational amplifier.
Figure 5 System power monitoring module.
The system power monitoring module is the core of the Ethernet power management system, which can realize the acquisition of a variety of signals and real-time monitoring of a variety of signals, such as current, voltage, power factor and other signals. Nowadays, it has been widely used in various fields such as schools and power stations.
2.5. Human-machine interface module.
The human-machine interface for intelligent monitoring is designed in the power management system. When the monitoring center needs to observe the user's real-time electricity consumption, the system will transmit the information collected by the data acquisition module to the monitoring center through the industrial Ethernet, and the power station management personnel can pass out the user's electricity consumption information transmitted by the main control module through the man-machine interface, and then realize the real-time monitoring of the site based on the man-machine interface, and the operating platform of the data system of the monitoring center is built based on the PC mechanism of the industrial Ethernet. The user's electricity data information is analyzed, communicated and interconnected through the PLC main control module, constituting a complete power management system, so that the remote analysis, control and monitoring functions of the entire power management system can be realized.
Therefore, through the analysis of the operation process of the power monitoring module of the power management system based on industrial Ethernet, the operation of the entire management system and the data in practical application are compared, and the operation of each part of the management system in the actual application of the field is analyzed, which shows that the power management system based on industrial Ethernet has achieved effective results.
3 Acrel-3000WEB power management solution.
3.1 Overview.
The user side consumes 80% of the power of the entire power grid, and the intelligent power management of the user side is of great significance to the reliable, safe and economical electricity consumption of the user. Build an intelligent electricity service system, comprehensively promote the user-side smart meters, intelligent power management terminals and other equipment power management solutions, and realize the two-way benign interaction between the power grid and users. The research content that needs to be solved urgently on the user side mainly includes: advanced metering, intelligent buildings, intelligent appliances, value-added services, customer power management system, demand-side management and other topics.
Acrel-3000WEB power management solution subdivides and counts the electricity consumption of the user, and displays the power consumption of each sub-item to the management personnel or decision-makers with intuitive data and charts, which is convenient to find out the high energy consumption points or unreasonable energy consumption habits, effectively save power, and provide accurate data support for users to further energy-saving transformation or equipment upgrades.
3.2. Application place.
1) Office buildings (business offices, large public buildings, etc.);
2) Commercial buildings (shopping malls, financial institution buildings, etc.);
3) Tourist buildings (hotels, restaurants, entertainment venues, etc.);
4) Science, education, culture and health buildings (culture, education, scientific research, medical and health care, sports buildings, etc.);
5) Communication buildings (post and telecommunications, communications, radio, television, data centers, etc.);
6) Transportation buildings (airports, stations, dock buildings, etc.).
3.3. System structure.
3.4. System functions.
3.4.1. Real-time monitoring.
The system has a friendly human-machine interface, intuitively displays the operation status of the distribution line in the form of a distribution diagram, monitors the voltage, current, power, power factor, electric energy and other electrical parameter information of each circuit in real time, and dynamically monitors the closing and sub-state of the circuit breaker, isolation switch, ground knife and other parts of the distribution circuit, as well as the signals such as faults and alarms.
3.4.2. Electric energy statistics report.
The system supports the integrity of the measurement system with rich reports. The system has the function of regular meter reading, and users can freely query the electricity consumption of each distribution node in any period of time since the normal operation of the system, that is, the statistical analysis report of the power consumption of the node and the power consumption of each branch circuit. This function makes the electricity consumption visible and transparent, and can be analyzed and traced when the power consumption error is large, so as to maintain the correctness of the metering system.
3.4.3. Detailed electrical parameter query.
In the primary power distribution diagram, when the mouse moves near each circuit, the mouse pointer changes to a hand shape, and the mouse can click to view the detailed electrical parameters of the circuit, including three-phase current, three-phase voltage, three-phase total active power, total reactive power, total power factor, forward active energy, and can view the 24-hour phase current trend curve and 24-hour voltage trend curve.
3.4.4. Run the report.
The system has the storage and management functions of real-time power parameters and historical power parameters, all real-time collected data, sequential event records, etc. can be saved to the database, and the parameters that need to be queried, the corresponding time or the record data that can be selected to be queried in the query interface can be displayed, etc., and displayed through the report. Users can customize the operation and monthly report according to their needs, support the export of Excel format files, and can also export PDF format files according to user requirements.
3.4.5. Transformer operation monitoring.
The system monitors the operation status of the main incoming line, main transformer and important load outlet line of the distribution system in real time, displays the operation trend of current, transformer operating temperature, active demand, active power, apparent power, transformer load rate and other operating trends with curves, analyzes the load rate and loss of transformer, and facilitates operation and maintenance personnel to grasp the operation level and power demand in a timely manner to ensure the safety and reliability of power supply.
3.4.6. Real-time alarm.
The system has a real-time alarm function, and the system can monitor the distribution circuit breaker, isolation switch, grounding knife division, closing action and other remote signal displacement, protection action, accident tripping, and voltage, current, power, power factor overrun and other events in real time, and issue alarms according to the event level. When the system alarms, the real-time alarm window will automatically pop up, and a sound or voice reminder will be issued.
3.4.7. Historical event inquiry.
The system can store and manage the event records such as remote signal displacement, protection action, accident tripping, and voltage, current, power, and power factor overrun, which is convenient for users to trace the history of system events and alarms, query statistics, and accident analysis.
3.4.8. Power quality monitoring.
The system can continuously monitor the power quality of the entire distribution system, and the operation and maintenance personnel can grasp the voltage, current harmonic distortion rate, harmonic content, voltage unbalance and so on of the incoming line, transformer and important circuit through the harmonic analysis bar diagram and report, and take corresponding measures in time to reduce harmonic loss and reduce the abnormality and accident caused by harmonics (this function needs to be equipped with a power meter with harmonic monitoring function, which does not need to be deleted.)
3.4.9 remote control operation.
The system supports remote control operation of circuit breakers, disconnectors, grounding knives, etc. The system has strict password protection and operation authority management functions, for each remote control operation, the system automatically generates operation records, including the operator, operation time, operation type, etc. To realize this function, the circuit breaker itself needs to be supported by hardware devices such as electric operation mechanism and protection measurement and control device, and remote control function.
3.4.10. User rights management.
In order to ensure the safe and stable operation of the system, the system has set up a user rights management function. Unauthorized actions (e.g., distribution circuit name modifications, etc.) can be prevented through user rights management. It can define the login name, password and operation authority of different levels of users to provide reliable security guarantee for system operation, maintenance and management.
3.4.11. Communication status diagram.
The system supports real-time monitoring of the communication status of each device connected to the system, and can completely display the entire system network structure; It can diagnose the communication status of the equipment, and automatically display the faulty equipment or components and their fault parts on the interface when the network is abnormal. In this way, it is convenient for operation and maintenance personnel to grasp the communication status of various equipment on site in real time, maintain abnormal equipment in time, and ensure the stable operation of the system.
3.4.12** Monitoring.
*The monitoring shows the current real-time picture (**live broadcast), select a substation, and you can view the ** information in the substation.
3.4.13 User Reports.
The user report page is mainly used to automatically summarize the operation data of the selected substation for one month, and perform statistical analysis on the transformer load, power consumption of the distribution circuit, power factor, alarm events, etc.
3.4.14 app support.
The power operation and maintenance mobile phone supports five modules: "monitoring system", "equipment file", "to-do list", "inspection record" and "defect record", and supports a map, demand, electricity consumption, curve, temperature and humidity, year-on-year, ring ratio, power quality, various event alarm query, equipment file query, to-do event processing, inspection record query, etc.
3.5. System hardware configuration list.
4 Concluding remarks. The power management system based on industrial Ethernet adopts new technology to integrate intelligent equipment into the electricity user, and under the condition that the user's electricity consumption data information can be fully collected, the industrial Ethernet is used to automatically collect and analyze the data, so as to realize the unified storage and analysis of the user's electrical information, which is of great significance to the realization of humanized management of electric energy. However, since there is no unified communication standard between the various management system products, and the implementation of a modern power management system cannot completely abandon the tradition. Therefore, the process of building a power management system based on industrial Ethernet is bound to be a tortuous and long process.