Abstract: Introduce the project of Adama industrial park, Ethiopia, which uses 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 via fieldbus and transmits it to the background. The Acrel-2000 power monitoring system realizes real-time monitoring and management of power distribution circuit power in the distribution room. Keywords: intelligent power meter; Acrel-2000; power monitoring system 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 parameters such as voltage, current, and power in the incoming and outgoing circuits of the power distribution room at 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 . 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. Data analysis and processing Comprehensive statistics and analysis of data need to achieve the following functions: 1.Statistics and calculation of the electricity consumption data of each equipment in hours, days, months, years and other time periods. 2.Calculate the large, small and average value of the electrical load (active power, reactive power) of each device. 3.Count the power consumption (active power and reactive power) of each substation and the whole. 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. 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. Energy-saving renovation and effect evaluation It is required to provide data support for the energy-saving transformation of production, and can provide the effect evaluation before and after the energy-saving transformation. 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.     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. System solutions   According to the actual situation of Adama industrial park, the overall network structure of Acrel-2000 system adopts shielded twisted pair to directly connect to the data collector and then directly connect to the monitoring host in the power distribution room through the network cable, ensuring the transmission of the power monitoring and monitoring system. The stability and real-time performance. 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 the Adama Project, it mainly refers to the monitoring host placed in the power distribution room on the first underground floor. 2.Network communication layer The communication layer is mainly composed of collectors, Ethernet devices and bus networks. The main function of the serial server is to monitor on-site intelligent instruments; the main function of Ethernet equipment and bus network is to realize the data interaction between the substation and the main station, so that the management of the power distribution system is centralized, informatized, and intelligent, and the power distribution is improved. The safety, reliability and stability of the system have achieved the goal of unattended operation. 3.Field device layer The field equipment 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. System structure diagram     System functions The real-time monitoring system diagram of the substation 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 in the figure below: 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 the low-voltage circuits of the incoming and outgoing lines of the Adama power distribution room, mainly including: three-phase current, active power and active power. 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: 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, the user can print the report directly, and save it to another location in EXCEL format. As shown below: 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 at the same time. 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.  Conclusion In the application of today’s power distribution facilities, the safety of the project’s power distribution is very important. The application of the Acrel-2000 power monitoring system in the Adama described in this article can realize the real-time power consumption of the power supply and distribution circuit in the power distribution room. Monitoring, not only can display the power status of the loop, but also has a network communication function, which can form a power monitoring system with a serial server, a 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 dialogs, 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, providing a true and reliable basis for the project to solve the electricity problem, and has achieved good benefits. Bibliography 1.Solutions For Enterprise Micro-grid System 2020.02

Abstract: This paper introduces the application of ackry APM series AC meter in the AC side of Bulgarian photovoltaic system. It is mainly used to measure the current in the photovoltaic system, and cooperate with the transformers to measure, communicate and control the circuit system. 1.Project Overview The company is located in Bulgaria. The company is mainly engaged in the design / installation, construction / maintenance of small photovoltaic power generation center projects in Bulgaria and surrounding countries. The customer wants to use AC meters apm801, apm810 and mutual inductors for monitoring, metering and communication of current and voltage at the AC side of photovoltaic system, and control by using the switching value function of APM meter.   2.APM Series Energy Meters APM series power meters of ACREL are power meters that 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. This series of meters use a modular design, with a rich function of the external DI / DO module, AI / AO module, event recording (SOE) module with T-Flash (TF) card, network communication module,Temperature and humidity measurement 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.   3.Type and Function Description Function APM800 (class 0.5s) APM801 (class 0.2s) APM810 (class 0.5s) Measured parameters Total electrical measurement √ √ √ Four-quadrant energy √ √ √ Pulse output of energy Pulse output of active/reactive energy √ √ √ Demand Three-phase current, active power, reactive power, real-time demand of apparent power, and maximum demand (including time stamp) √ √ √ Extreme value statistics Extremum of current, line voltage, phase voltage, active power, reactive power, apparent power, power factor, frequency, total harmonic of current, total harmonic of voltage in this month and last month (including time stamp) √ √ √ Power quality Unbalance of current, line voltage, phase voltage √ √ √ Voltage phase angle, current phase angle √ √ √ Voltage current phase Angle √ √ √ Total (odd, even) harmonic content of voltage and current × × √ Harmonic content of voltage and current (2-63 times)① × × √ Voltage crest factor × × √ Telephone waveform factor × × √ Current K-factor × × √ Alarm records A total of 66 kinds of alarm types, each type can record the most recent 16 alarm records, support extended records by TF card √ √ √ Event log Record the most recent 128 event records, support extended records by TF card √ √ √ Communication Modbus protocol √ √ √ I/O 2 digital inputs + 2 digital outputs (2DI+2DO) √ √ √ Extensions MD82 8 digital inputs + 2 digital outputs with changeover contacts (8DI+2DO) √ √ √ MLOG TF card storage (alarm records, event records, electrical parameters and energy timing records, etc.) √ √ √ MA84 8 analog inputs (class 0.5) + 4 analog outputs (class 0.5) (8AI+4AO) √ √ √ MCM 1 RS485/Modbus-RTU, support master mode or slave mode √ √ √ MCP 1 Profibus-DP √ √ √ MCE 1 Ethernet, support Modbus-TCP, http, SMTP, DHCP protocol √ √ √   MTH 4 ways of temperature measurement, 1 way of temperature and humidity control √ √ √   Note ①: Accuracy of  2~42 times harmonic measurement in the frequency range of 45~65Hz is 1%, accuracy of 43~63 times harmonic measurement in frequency 50Hz is 2%.   4.技术参数Technical parameters Technical Parameters Index Signal Electrical network Three-phase three-wire, three-phase four-wire, see the wiring diagram; Frequency 45～65Hz； Voltage Rated value：AC 100V、110V、400V、690V； Overload: 1.2 times rated value(continuous); 2 times rated value /1 second; Power consumption: < 0.5VA (per channel); Current Rated value: AC 1A, 5A, support 4 mm2 line access; Overload: 1.2 times rated value(continuous); 10 times rated value/1 second; Power consumption: < 0.5VA (per channel); Measurement accuracy Voltage、current and power class 0.5s/class 0.2s (APM800、APM810/APM801) Active power class 0.5s/class 0.2s (APM800、APM810/APM801) Reactive power class 2 Harmonic 1%（2rd~42nd）、2%（43rd~63rd） Switch inputs Dry contact inputs, built-in power supply; Relay outputs Contact type: open contact in main part, changeover contact in module; Contact capacity：AC 250V/3A  DC 30V/3A； Pulse output of energy Output mode: Optocoupler pulse with open collector; Pulse constant：4000（5A）、8000（1A） imp/kWh； Analog outputs DC 0mA～20mA、4mA～20mA、0V～5V、1V～5V output, accuracy class 0.5%, load resistance ≤ 500Ω; Analog inputs DC 0mA～20mA、4mA～20mA、0V～5V、1V～5V iutput, accuracy class 0.5% Storage card Standard Capacity:4G,TF Card Up to 32G Capacity; Communication RS485 interface/Modbus-RTU protocol and DLT645 protocol Profibus-DP interface/Profibus-DP protocol; RJ45 interface (Ethernet) / Modbus-TCP, http, DHCP and other protocols; Power supply Working range: AC/DC 85V～265V or AC/DC 115～415V(P2); Power consumption: Power consumption of the main part ≤ 15VA; Safety Power frequency withstand voltage The power frequency withstand voltage between the shell and the auxiliary power supply, each input and output terminal group is AC 4kV/1min; The power frequency withstand voltage between the auxiliary power supply and each input and each output terminal group is AC 2kV/1min; The power frequency withstand voltage between the voltage input and other input/output terminal groups is AC 2kV/1min; The power frequency withstand voltage between the current input and other input/output terminal groups is AC 2kV/1min; The power frequency withstand voltage between the relay output and other input/output terminal groups is AC 2kV/1min; The power frequency withstand voltage between each terminal group of switch input, communication, analog output and pulse output is AC 1kV/1min;   Insulation resistance Inputs、outputs to the shell>100MΩ； Electromagnetic compatibility Meet IEC 61000 standard (Level 4); Protection level Display panel IP52 Environment Operating temperature: -20 °C ~ +65 °C; Storage temperature: -20°C～+70°C; Relative humidity: ≤95% without condensation; Altitude: ≤2500m; Standards IEC 60068-2-1 IEC 60068-2-2 IEC 60068-2-30 Environmental Testing-Part 2-1:Tests Test A:Cold IDA Part 2-1:Tests Test B:Dry heat Part 2-30:Tests Test Db:Damp heat,cyclic(12+12h) IEC 61000-4 Electromagnetic compatibility-Testing and measurement techniques   IEC 61557-12 Electrical safety in low voltage distribution system up to 1000V a.c. and1500V d.c –Equipment for testing,measuring or monitoring of protective measures- Part12： Performances measuring and monitoring devices(PMD)  IEC 62053-22 Electricity metering equipment (a.c.)-Particular requirements - Part22:Static meter for active energy（class 0.2s and 0.5s）     5.Requirements from Customer terms of reference from grid supplier: （1）monitoring voltages: L1-N, L2-N, L3-N. Unominal = 230V; （2）switching relay output at overvoltage: 2 steps:  Step 1: 110% of Unominal or 253V - delay 60 seconds (s) ;  Step 2: 115% of Unominal or 264V - delay 0.1s; （3）switching relay output at undervoltage: 1-step; 80% of Unominal or 184V - delay 0.2s; Range of settings: U: 10-100% of Unominal, step not listed, maybe 1V ot 1%; Delay: 0.05 s to 3s, step - not listed, maybe 1s; （4）switching relay output at overfrequency 1-step; 50.5Hz - delay 0.1s; Range of settings: F: 50-52.5Hz, step 0.1Hz; Delay: 0.1-0.5s, step - maybe 0.1s; （5）switching relay output at overfrequency 1- step; 47.5Hz - delay 0.1s; Range of settings: F: 47.5-50Hz, step 0.1Hz; Delay: 0.1-0.5s, step - maybe 0.1s; （6）Delay for recovering. When DO is on by some of previous reasons, there should be time delay after grid parameter(s) are back in nominal range(s). Time range 1-60s, step 1s （7）Additional settings. (If they are possible).    7.1 When Unominal is lower than 60-70%, under and overfrequency monitoring can be disabled 7.2 When overfrequency/underfrequency is happened - the DO should not be recovered automatically, it should wait for some kind of manual/remote restore. Note:The above 7 items are the special needs of customers for the purchased products. Except that some requirements in point 7 cannot meet the needs of customers, other needs can be met. Basically solved the needs of customers. 6.Installation Picture