Smart Grid User-End Power Management System

1.1 Overview

With the rapid development of economy, energy shortage and environmental deterioration have attracted close attention from the world. Energy is an important foundation for the development of national economy. In order to respond to the call of the country and take the road of sustainable development, energy saving and consumption reduction are the top priorities. Among them, electricity is consumed in a relatively large amount among all energy sources, so the unified management of electricity is particularly important. Only by accurately and reliably measuring electricity can we save electricity in a real sense.

Acrel-3000 series power management system is a set of power management system suitable for low-voltage power distribution system, which is developed by our company in accordance with the standards and specifications of power system and with strong professionalism, high degree of automation, easy to use, high performance and high reliability. Through telemetry and remote control, load can be reasonably allocated, optimized operation can be achieved, power can be effectively saved, and peak and valley power consumption records can be kept, thus providing necessary conditions for energy management. At the same time, combined with the "Technical Guidelines for Design and Installation of Building Sub-item Metering of Energy Consumption Monitoring Systems for Office Buildings of State Organs and Large Public Buildings" (Jian Ke [2008] No. 114), power is measured in sub-items according to power consumption of exposed sockets, power consumption, air conditioning consumption and special consumption, providing a basis for power energy conservation audits of enterprises and institutions.

1.2 Structure

Acrel-3000 power management system can measure the power consumed by low-voltage equipment by item. Its software runs on Windows operating system, including Windows 2000, Windows NT, Windows XP and other Windows series operating systems. In addition to being well compatible with the instruments independently developed by our company, the system also supports hundreds of hardware devices, including various popular boards, instruments, PLCs, etc. It supports various commonly used power communication protocols, such as the CDT protocol issued by the ministry, POLLING, 1801, 101, DNP and other power protocols.

In accordance with the relevant national requirements for electric energy metering, this system measures power consumption by item, including:

(1) Electricity consumption for lighting sockets: refers to the electricity consumption for indoor equipment such as lighting and sockets in the main functional areas of a building. It mainly includes electricity consumption for lighting and sockets in the building, electricity consumption for emergency lighting, electricity consumption for outdoor landscape lighting, etc.

(2) Electricity consumption for air conditioning: mainly includes electricity consumption for cooling and heating stations and electricity consumption for air conditioning terminals.

(3) Power consumption: mainly includes electricity consumption for elevators, water pumps, ventilators, etc.

(4) Special electricity use: mainly includes information center, laundry room, kitchen and restaurant, swimming pool, gymnasium or other special electricity use.

1.3 Functionality

1.3.1 Front-end human-computer interaction interface

Design an interactive interface that suits customer requirements; standard graphic element library for easy calling and combination; real-time data acquisition and display; automatic logical calculation and processing of data information; remote change and setting of equipment parameters; closing and opening status display and forced operation.

1.3.2 Curve and report management settings

Trend curves of electrical parameters required by customers; historical trends of positive/reverse active/reactive electricity; design various reports to meet customer needs; automatically generate daily, monthly and annual reports for energy metering; set templates based on commonly used MS Excel and generate corresponding reports for easy use by users; query, display and print reports at any time.

1.3.3 Backend database management

Widely used database software such as Access and MSSQL; establishment of open and networked database; storage of data information for a specified period of time or all data; dynamic link library implemented by the software system; real-time data information update is safe and reliable; support C/S and B/S methods to realize remote data transmission.

1.3.4 Multi-level permission user management

Password login backend ensures security of settings; high-authority management over low-authority, hierarchical operations, each authority has the function of changing passwords.

1.3.5 Communication Management Settings

Each serial port can be configured independently, which is easy to operate; the communication protocol of different devices can be selected; the communication baud rate can be selected independently; the system can automatically perform unified remote control configuration for each device connected to a port of the front-end machine according to the selection result.

1.3.6 Network Function

The dual-machine hot standby function supports dual-machine, dual-network, dual-device and other redundancies, and uses hot standby to ensure stable and reliable operation of the system. The configuration is simple and convenient. Any machine on the network can be designated as an I/O server (i.e., front-end machine), and other machines on the network can easily obtain data from this machine.

1.4 Software Interface

1.4.1 Data Collection

It can collect and process various telemetered quantities, telesignal quantities, pulse quantities, etc. commonly used in power systems. For example: telemetered quantities: voltage, current, active power, reactive power, etc.; telesignal quantities: switch status, switch position, protection action signal, accident tripping total signal, warning signal, etc.; pulse quantities: electrical quantity, frequency, time quantity, equipment parameters, protection setting value, etc.; non-electrical quantity: temperature, pressure, humidity, fire alarm, anti-theft alarm, etc.

1.4.2 Main interface display

It can be represented graphically based on the equipment installation situation and layout on site. The figure is the power distribution diagram of the low-voltage system.

1.4.3 Query of monthly meter reading data

Display the meter data of a certain month, and perform custom queries and print output.

1.4.4 System Operation Status Diagram

The system's switching quantity, analog quantity, and pulse quantity list, record the number of switching quantity position change actions, the system's protection device protection drop-out table, protection setting table, each microcomputer device signal table, the number of days the system is running safely. The system's pulse power readings, daily, monthly, and annual statistical lists, etc.

Display the current operating status of on-site system equipment and system operating information.

1.5 Performance Indicators

●Mean trouble-free working time>30000h;
●Telemetry transmission time<3s;
●Telesignal quantity: telesignal change time<3s, telesignal accuracy 100%;
●Remote control, remote adjustment: remote control, remote adjustment transmission time<3s, remote control accuracy 100%;
●Screen image call response time<3s;
●Alarm response time<2s;
●Real-time screen data update time<3s;
●Switch quantity update time in the database<2s;
●Analog quantity update time in the database<2s;
●System capacity can be expanded infinitely according to the expansion of hardware configuration.

1.6 Application Scheme