Abstract: Introduce an international commercial plaza project, which adopts smart power meters to collect various electrical parameters and switch signals at the distribution site. The system adopts the method of on-site networking. After networking, it communicates via fieldbus and transmits it to the background. The Acrel-3000 power management system realizes real-time monitoring and management of the power consumption of floors and power distribution rooms.
Keywords: intelligent power meter; Acrel-3000; Energy management system;
0 Overview
The project is located in the core of an economic development zone, with mature development, complete supporting facilities and convenient transportation. This project is the energy utilization transformation of the distribution rooms on each floor of the site. On-site 757 power distribution outgoing circuits were installed with 757 multi-function meters to collect field data.
1 Demand Analysis
To ensure the statistics and analysis of electricity load for production management and real-time monitoring of hazard sources. Real-time online monitoring of voltage, current, power and other parameters of electrical equipment such as distribution boxes on the project site is required. Once the monitoring point is monitored with abnormal parameters, it can detect and alarm in time, and relevant personnel can take necessary measures to avoid safety accidents. The automatic meter reading function saves manpower and material resources. The power trend curve function can intuitively display the working status and time of each circuit, which is convenient for users to find abnormal power circuits and make corrections in time, and establish a multi-level electrical energy measurement system to provide energy analysis basis .
This technical condition applies to the incoming and outgoing circuits of the project. The supplier's products should have high safety and reliability, easy to expand, easy to repair and maintain. The products provided by the supplier shall meet the technical requirements at least, but not only this, but the technical performance shall meet the requirements for data monitoring of the equipment distribution box.
1.1 Data Collection
Automatically collect analog data of all power meters on site, and automatically collect on-site switching data such as on-site switch status and fault status.
Support real-time collection, automatic periodic collection (timing collection) configurable cycle (1 minute to 24 hours).
Support data transmission correctness inspection, automatic processing of abnormal data.
Support multi-threaded processing mechanism, improve the efficiency of data collection, and can collect data from multiple devices at the same time.
The real-time data display adopts the intuitive display mode of the main wiring diagram of the distribution box, and the disconnection and fault status of each circuit switch are intuitively visible.
1.2 Data Analysis And Processing
Comprehensive statistics and analysis of data need to achieve the following functions:
Statistics and calculation of the electricity consumption data of each equipment within hours, days, months, years and other time periods.
Calculate the large, small and average value of the electrical load (active power, reactive power) of each device.
Count the power consumption (active power and reactive power) of each substation and the whole.
1.3 Data Query And Display
It is required to facilitate the realization of client query and query of managers at all levels. The query interface can adapt to the requirements of managers at all levels. It can support flexible condition combination query and comparative analysis. Various types of statistical analysis data can be flexibly used in reports and other charts. Intuitive display function.
According to the different permissions of different users, the data display function is divided into three layers: operation layer, management layer, and decision-making layer.
The operation layer has functions such as energy consumption analysis, cumulative consumption, real-time monitoring, running records and ratios, comparison, and benchmarking analysis.
The management has functions such as statistics and analysis of energy consumption data, comparison of classification and sub-items, and benchmarking analysis.
The decision-making layer has functions such as energy data analysis, data deletion, and database import/export.
1.4 Authority Management
It is required to assign different roles to different users, and be able to authorize function sub-menus, specific file records, data records, etc.
The system requires a reasonable and complete user security control mechanism to protect the information resources in the application environment and prevent the loss, theft and destruction of information.
1.5 Energy-Saving Renovation And Effect Evaluation
It is required to provide data support for the energy-saving transformation of production, and provide the effect evaluation before and after the energy-saving transformation.
1.6 Parameter Settings
The transformer ratio of each loop and the setting value of various current and voltage protection can be set through the acquisition cabinet.
Fault judgment and alarm have automatic fault judgment and use sound and light alarm function. Alarm types include switch failures, voltage and current overruns, communication failures of the field acquisition module, and communication failures with the monitoring system. The alarm time is automatically recorded in the system database, which is convenient for users to inquire. The staff can grasp the real-time operation status of the substation at any time, find the operation failure of the substation and distribution, and make corresponding treatments, improve the management efficiency of the substation and distribution, and enhance the safety of the power system. reliability.
2 System Solutions
According to the actual situation of the project site, the Acrel-3000 system uses shielded twisted-pair cable to connect directly to the corresponding data collector in the monitoring room and then directly connects to the monitoring host through the network cable, ensuring the transmission of the power management monitoring system. The stability and real-time performance. As shown in the figure below: station control management layer, network communication layer and field device layer.
A total of 140 multi-function instruments on site are divided into 12 RS485 buses connected to the monitoring industrial computer in the power distribution room to realize the data connection between the instruments on the bus and the monitoring host.
1）Station Control Management
The station control management layer is the direct window of human-computer interaction for the management personnel of the power monitoring system. In this project, it mainly refers to the monitoring host placed in the power distribution room.
2）Network Communication Layer
The communication layer is mainly composed of the communication serial port of the monitoring industrial computer, Ethernet equipment and bus network. The main function of the serial port is to monitor on-site intelligent instruments; the main function of the Ethernet equipment and the bus network is to realize the data interaction between the substation and the main station, so that the management of the distribution system is centralized, informatized, and intelligent, which greatly improves the distribution The safety, reliability and stability of the electrical system have achieved the goal of unattended operation.
3）Field Device Layer
The field device layer is the data acquisition terminal, which is mainly composed of smart meters. The smart meters are connected to the communication server through the shielded twisted pair RS485 interface and the MODBUS communication protocol bus connection. The communication server reaches the monitoring host of the power distribution room for networking. Realize remote control.
4) Smart Instrument Connection Diagram
Field instruments are connected hand in hand through shielded twisted pair (RVSP2*1.0). The number of smart instruments connected to each bus is about 20. Different types of smart devices are connected to different buses, and then the data is uploaded to the serial port. The server then uploads the data to the local monitoring terminal. The specific connection diagram is as follows:
3 System Functions
The on-site real-time monitoring system diagram is the main monitoring screen, which mainly monitors the operating status of all circuits in the substation in real time. Red represents closing and green represents opening. In the system diagram, you can intuitively see the operating parameters and status of each incoming and outgoing line, and you can see all the conventional power parameters on the outgoing side of the transformer, such as: three-phase voltage, current, active power, reactive power, and power factor , Frequency, active power, etc. As shown below:
System diagram
The remote signaling and remote measurement alarm function mainly completes the monitoring of the switch operation status of the low-voltage outlet circuits and the load incoming line. The pop-up alarm interface for switch displacement and load limit violations indicates the specific alarm location and sounds the alarm to remind the duty personnel to deal with it in time. The load limit can be set freely under the corresponding authority. With historical query function.
The event alarm recording function mainly completes the recording of the alarm information and the occurrence time of the alarm information that occurred during the query time period, and provides the basis for the staff on duty and analyzes the cause of the accident.
Parameter meter reading function, mainly to query the electrical parameters of the low-voltage outgoing circuit. Supports electrical parameter query at any time, with functions such as data export and report printing. This report queries the electrical parameters of the low-voltage circuits of the incoming and outgoing lines of the distribution box on the floor of the Yike Building, mainly including: three-phase current, active power and active energy. The name of each circuit in this report is associated with the database, which is convenient for users to modify the name of the circuit. As shown below
Electric parameter reading
The power consumption report function can select the time period for query, supports the cumulative query of the power consumption at any time period, and has the functions of data export and report printing. Provide accurate and reliable electric energy report for the staff on duty. The name of each circuit in this report is associated with the database, which is convenient for users to modify the name of the circuit. As shown in the figure below, it shows the accurate power consumption of the power distribution circuit in the laboratory building of the office building. Users can directly print the report and save it to other locations in EXCEL format. As shown below:
Energy report
A schematic diagram of the system communication structure, which mainly shows the network structure of the system. The system adopts a hierarchical distributed structure and monitors the communication status of the bay layer equipment. Red indicates that the communication is normal, and green indicates that the communication is faulty. The figure below is a schematic diagram of the communication status of the substation.
Communication structure diagram
In the load trend curve interface, the load operation of the loop can be viewed intuitively. View real-time and historical trend curves, click the corresponding button or menu item on the screen to complete the switch of the corresponding function; help users to enter the line trend analysis and fault recall, with the curve printing function. Provides intuitive and convenient software support for analyzing the operating status of the entire system.
4 Summary
In the application of today’s power distribution facilities, power distribution safety is of the utmost importance. The application of the Acrel-3000 power management system introduced in this article in the commercial plaza project can realize real-time monitoring of the power consumption of the power supply and distribution circuit, not only can display the circuit The power consumption status also has the function of network communication, which can form an electric energy management system with serial server, computer, etc. The system realizes the analysis and processing of the collected data, real-time display of the operating status of each power distribution circuit in the power distribution room, pop-up alarm dialogs, voice prompts for load overruns, and generates various energy reports, analysis curves, graphics, etc., It is convenient for remote meter reading, analysis and research of electric energy. The system is safe, reliable and stable in operation. It provides a safe and reliable basis for the commercial plaza project to solve electricity problems, and has achieved good corporate benefits.
Bibliography
1.Technical requirements of the Ministry of Housing and Urban-Rural Development[2008] No. 114.
2.Solutions for enterprise micro-grid system
