Abstract:Introduce of Hawassa industrial park project, which adopts intelligent 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 through the field bus and transmits it to the background. The power management system realizes real-time monitoring and management of the power consumption of the substation.

Keywords:smart power meter; power distribution room; power management system

0Overview
  Hawassa Industrial Park is located in Ethiopia, Africa。
  The protection device, electric energy meter, etc. in the AH1~AH14 cabinets of the 10KV power distribution room at the project site monitor the real-time electrical parameters and other data of the power supply and distribution system during operation.

1Demand analysis

solution:
1) 10kV/35kV substation integrated automation system;
2) Intelligent monitoring background system of distribution network switch station;
3) Coordinated control platform on the demand side of electricity
To ensure the statistics and analysis of electricity load for production management and real-time monitoring of hazard sources. It is necessary to conduct real-time online monitoring of parameters such as voltage (U), current (I), and power (P) in the incoming and outgoing circuit of the distribution box at the project site. 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 .
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 distribution box.

2  System solutions
  According to the actual situation of the project, the Acrel-2000 system uses a shielded twisted pair cable to directly connect to the data collector and then directly connect to the monitoring host in the duty room through a network cable. , To ensure the stability and real-time transmission of the power management monitoring system.
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 of the power distribution room.

  The communication layer is mainly composed of collectors, Ethernet devices and bus networks. The main function of the communication management machine is to monitor the 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 This improves the safety, reliability and stability of the power distribution system, and achieves the goal of unattended operation.
This project uses Acrel's self-developed communication management machine ANet-2E8S1, which provides 2 10/100M Ethernet interfaces, 8 optocoupler isolation RS485 and 1 RS232 (debugging port), which can support 256 metering devices.
  ANet intelligent communication management machine provides rich protocol library support to realize the interconnection of intelligent equipment of different secondary equipment suppliers.
  The field device layer is the data acquisition terminal, which is mainly composed of microcomputer protection and 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. Networking to realize remote control.
  This project uses Acrel's microcomputer line protection and measurement device AM5-F and embedded installation electric energy metering device AEM96.

3  System functions
  The 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.      
  The remote signaling and remote measurement alarm functions mainly complete 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.
  The event alarm record function mainly completes the record 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, as shown in the following figure:
  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 each low-voltage circuit of the inlet and outlet lines of the distribution box of this project, 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. 
  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 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, the user can print the report directly, and save it to another location in EXCEL format.

4  Concluding

  In the application of today’s power distribution facilities, the safety of the project’s power distribution is of paramount importance. The power management system introduced in this article is applied to the Hawassa industrial park project, which can realize power distribution in substations. The real-time monitoring of loop power consumption can not only display loop power consumption status, but also has network communication function, which can form a power management system with communication management machines and computers.
  The system realizes the analysis and processing of the collected data, real-time display of the operating status of each distribution circuit in the power distribution room, pop-up alarm dialog box, voice prompts for load exceeding limit, and generates various electric energy reports, analysis curves, graphics, etc., which is convenient The remote meter reading, analysis and research of electric energy show that the system is safe, reliable and stable, which provides a real and reliable basis for the project to solve electricity problems, and has achieved good benefits.