Abstract: This article introduces the application of the multi-function energy meter in a farm in Mozambique and the solution of energy management system. The system adopts intelligent power meters to collect various electrical parameter and switching signals at the distribution site and the way of local networking, communicate via field bus and upload to background after networking.

Keywords: Energy meter; Industrial projects; Intelligent power meter; Energy management system

1. Project Overview

The farm is located in Nampula, Mozambique, and mainly uses a three-phase electric energy meter APM800 and split core current transformers.It is used for electric energy and power measurement, and has event recording and data report export function.

Acrel-3000 energy management system provides decentralized data acquisition and centralized monitoring and management of the substation and distribution system. It networks the secondary equipment of the power distribution system, connects the field equipment of scattered substation into an organic whole through computer and communication network, realizes remote monitoring and centralized management of grid operation.

2.System Introduction

This system adopts a hierarchical distributed structure,that is，the equipment layer, the communication layer and the station control management layer.

The equipment layer is mainly multi-function energy meters. The corresponding primary equipment of these devices are respectively installed in the electrical cabinet. These devices all adopt RS485 communication interface,and realize data collection through field MODBUS network communication.

The communication layer is mainly an industrial serial server.Its main function is to centrally collect the devices scattered in the field and transmit data to the station control management layer at the same time to complete the data interaction between the equipment layer and the station control management layer.

The station control management layer is equipped with high-performance industrial computers, monitors, UPS power supplies, printers and other equipment.The system is installed on the computer, collects and displays the operating status of the field equipment, and displays it to the user in the form of human-computer interaction.

3.Main Function

3.1 Data acquisition and processing

Data collection is the basis of power distribution monitoring. The data collection is mainly completed by the bottom multi-functional network instrument collection to realize the 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, electricity EpI, remote device operating status and other data.

Data processing is mainly to display the electrical parameters collected as required to users in real time and accurately to meet the requirements of automation and intelligence for power distribution monitoring. At the same time, the collected data is stored in the database for users to query.

3.2 Human-computer interaction

The system provides a simple, easy-to-use and good user interface. Adopt full Chinese interface, graphically display the primary electrical wiring diagram of low-voltage power distribution system, display the status of power distribution system equipment and corresponding real-time operating parameters, the screen will switch regularly; the screen will be dynamically refreshed in real time; analog display; switch display; continuous recording display etc.

3.3 Historical events

The historical event viewing interface mainly provides convenient and friendly human-computer interaction for users to view the fault records, signal records, operation records, and limit violation records that have occurred. Through the historical event viewing platform, you can conveniently locate the historical event you want to view according to your own requirements and query conditions, and provides good software support for you to grasp the operation of the entire system.

3.4 Database establishment and query

It mainly completes the timing collection of remote measurement and remote information, and establishes a database, and generates reports on a regular basis for users to query and print.

3.5 User authority management

For users of different levels, different authority groups are set to prevent the loss of production and life due to human misoperation, and realize the safe and reliable operation of the power distribution system.Users can log in, log out, modify passwords, add and delete operations through user management, which is convenient for users to modify accounts and permissions.

3.6 Report query

The main function of the report management program is to design report styles according to the needs of users, filter, combine and count the data processed in the system to generate report data that users need.This program can also adopt the regular saving, printing or summon saving and printing modes for the report file according to the needs of users.At the same time, this program also provides users with the function of managing the generated report files.

The report has the functions of freely setting the query time to realize the electric energy statistics of the day, month and year, data export and report printing.

4 Product Introduction

Name and Type	Picture	Description
APM810 Multi-function energy meter		APM series power meters are designed according to IEC standards and synchronized with international advanced technology. APM series meters have full power measurement, energy statistics, analysis of power quality and network communications and other functions, are mainly used for comprehensive monitoring of the quality of power supply network. It uses a modular design, with multiple function of the external DI / DO module, AI / AO module, event recording (SOE) module with T-Flash (TF) card, network communication module, can achieve full power measurement of electrical circuit and monitoring of switch status. Dual RS485 with Ethernet interface can realize data copying of RS485 master station, eliminating the need for data switching exchange. PROFIBUS-DP interface can realize high-speed data transmission and networking function.
AEM96 Multi-function energy meter		AEM three-phase embedded multi-function energy meter is a smart meter designed for power supply system, industrial and mining enterprises and utilities to calculate the electricity consumption and manage the electric demand. It can measure all electric parameters, four-quadrant electricity metering, multi tariff, maximum demand, historical data on electricity consumption, switching input incident record, historical extreme values record, analysis of 31st harmonic content and total harmonic content, A, B, C three phase and fundamental parameter(voltage, current, power). switching value, alarm output, RS485 (MODBUS or DL/T645-2007 protocol)
AMC96L-E4/KC Intelligent power collection and monitoring device		AMC96L-E4 intelligent power collection and monitoring device integrates measurement of parameters(voltage, current, active power, reactive power, apparent power, frequency, power factor) and power monitoring and assessment management. It has RS485 communication interface and Modbus-RTU protocol and can meet the needs of communication network management. High-brightness LCD display interface, parameter setting and control through buttons, ideal for energy management system.
ADL3000-E Din rail three phase energy meter		ADL3000-E is a smart meter designed for power supply system, industrial and mining enterprises and utilities to calculate the electricity consumption and manage the electric demand. It features the high precision, small size and simple installation. It integrates the measurement of all electrical parameters with the comprehensive electricity metering and management provides various data on previous 12 months. It checks the 31st harmonic content and the total harmonic content, realizes the remote communication and the remote control with switching input and relay output and boasts the alarm output. It is fitted with RS485 communication port and adapted to Modbus-RTU.
ADL100-ET Din rail single phase energy meter		ADL100-ET single phase energy meter is designed to measure single phase active energy(positive and negative) and electrical parameters. It has 8 bits section LCD display and 3 buttons. It supports RS485(Modbus-RTU) and infrared communication.
ADL10-E Din rail single phase energy meter		ADL10-E single phase energy meter is designed for single phase energy measurement on low voltage system. It has 8 bits section LCD display and scroll display function. It supports RS485(Modbus-RTU) communication.

5.Project Summary

It is paramount important that the safety of the projects in the application of power distribution facilities.This article introduces the application of Acrel-3000 energy management system can realize real-time monitoring of power supply and distribution circuits in power distribution rooms.

It can not only display the power consumption status of the loop, but also has the function of network communication, and 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 operation status of the distribution circuits in the distribution room, pop-up alarm dialog, voice prompt for load exceeding limits, and generates various electric energy reports, analysis curves, graphics, etc., which is convenient for remote meter reading, analysis and research of electric energy.

The system is safe, reliable and stable in operation, providing a true and reliable basis for industrial projects to solve power problems, and has achieved good benefits.

6.Field picture