Ankerui-5000 energy consumption monitoring system based on DTSF1352 electric meter

0 Introduction

The Regulations on Energy Conservation in Public Institutions (Order No. 531 of the State Council of the People's Republic of China, signed by Premier Wen Jiabao, was adopted at the 18th Executive Meeting of the State Council on July 23, 2008, and came into effect on October 1, 2008. Article 14 of the Regulations clearly states that public institutions shall implement an energy consumption metering system, distinguish energy consumption types and energy consumption systems, implement household, category, and item-by-item energy consumption metering, and monitor energy consumption to promptly discover and correct energy waste. Document No. 277 of Jianzhi (2006) "National Civil Building Engineering Design Technical Measures - Energy Saving Special Electrical Volume" proposed that electrical circuits should be equipped with electric energy metering devices, and Jiangsu and Shanghai also launched Document No. 217 of Sujianke (2007) "Jiangsu Province Public Building Energy Metering Design Regulations" and Document No. 828 of Hujianjiao (2008) "Notice on Further Strengthening the Management of Professional Energy Saving Design Technology of Civil Building Equipment in the City", which further clearly proposed the sub-item metering of major power facilities, office buildings, shopping malls, dormitories, etc. should be measured to economic accounting units; medical wards, hotel rooms, school classrooms should be measured by floor or functional area, etc., and included in the drawing review and completion acceptance standards.

At present, the installation of terminal electric energy metering meters generally adopts the traditional wall-mounted installation method, which has the disadvantages of large size and inconvenient installation. The DDSF1352/DTSF1352 rail-mounted electric meter adopts modular design, which has the advantages of small size, easy installation, easy networking, etc., and is easy to realize terminal distribution electric energy metering. It is convenient for the transformation of the power distribution system to install an electric meter.

1 Introduction to DDSF1352/DTSF1352 Electric Meter

1.1 Product Features

DDSF1352/DTSF1352 single-phase and three-phase electronic multi-rate electric meter is installed on DIN35mm track, with modular design and width matching the miniature circuit breaker, 4 and 7 modules respectively, which can be easily installed in the lighting box (see Figure 1). The maximum current connected at one time is 20 (80) A. If it is above 80A, an external CT is required, and the maximum transformation ratio can be expanded to 6000/5A. The electric meter has an RS485 communication interface and supports MODBUS-RTU protocol or DL/T645 protocol. The transparent cover and shell on the terminal block can be sealed with lead to prevent electricity theft. In addition to being used for internal electric energy measurement and assessment management of enterprises and institutions, this meter can also be used as a trade settlement meter after being tested and verified by the power supply department. This product complies with the requirements of GB/T 17215-2002 "Class 1 and Class 2 Static AC Active Energy Meters" and GB/T 15284-2002 "Special Requirements for Multi-rate Electric Energy Meters".

Figure 1 Appearance and installation of electric meter

1.2 Design principle

1.2.1 Design principle of single-phase DDSF1352 electric meter

DDSF1352 single-phase multi-rate electric energy meter is designed with ADI's latest technology ADE7169F16 system-on-chip. ADE7169 integrates high-precision metering unit module and 8052 MCU and its peripheral modules. The metering module has high metering accuracy and can measure the current and voltage effective value of each phase, each phase and total active power, reactive power, grid frequency and other operating parameters, and has a large overload multiple. The on-chip 8052 MCU has 16K FLASH and 512B RAM and a variety of peripheral modules, supports low-power temperature compensation on-chip RTC module, LCD driver module, power management module, SPI/I2C interface module and UART communication module, etc. A single-phase multi-rate multi-function electric energy meter design can be realized with one ADE7169. The specific design block diagram is shown in Figure 2.

Figure 2 Schematic diagram of the principle of the single-phase DDSF1352 meter

1.2.2 Design principle of the three-phase DTSF1352 meter

The DTSF1352 three-phase electronic multi-rate energy meter is implemented using the metering chip ATT7030A and Freescale's 8-bit single-chip microcomputer M68HC908LJ12. Its principle is: the real-time voltage and current on the line are coupled by a high-precision mutual inductor, and the sampling circuit samples them respectively, and then sent to the power metering dedicated chip ATT7030A (the A/D converter converts them into digital signals, and outputs power pulses after the dedicated DSP calculation on the chip), and then sent to the MCU through pulses, and completes the time-sharing active and reactive power metering and maximum demand calculation according to the pre-set time period, and makes corresponding processing respectively, and stores them in the EEPROM; at the same time, it realizes display and output, and RS485 serial data transmission. The specific design block diagram is shown in Figure 3.

Figure 3 Schematic diagram of the three-phase DTSF1352 meter [page]

2 Application cases

2.1 Primary solution

Take a student dormitory building of a certain university of science and technology as an example. The building has 4 floors, with 24 dormitories on each floor, equipped with public toilets, laundry rooms, and public bathrooms. The electrical primary solution is shown in Figure 4. The main distribution box incoming line circuit is equipped with a screen-mounted ACR230ELH multi-function power meter to measure the total power of the dormitory. It includes 34 electrical parameters such as three-phase active power, reactive power, power, power factor, current, voltage, frequency, and phase power. Detection and analysis of 2nd to 31st harmonic components of current and voltage, current and voltage imbalance, and positive and negative zero-sequence components of current and voltage. Each floor, emergency lighting, fan, and reserved electrical trunk line are respectively responsible for measuring the three-phase active power by 7 DTSF1352 meters. The meters can be installed in parallel with the CM1 circuit breaker on the guide rail, or they can be installed on the top of the box. The electricity in the dormitory rooms, public toilets, laundry rooms and corridors on each floor is measured by 27 single-phase electricity meters DDSF1352, and the public bathroom is measured by 1 three-phase electricity meter DTSF1352.

Figure 4 Primary electrical scheme of dormitory building

2.2 System networking

The primary scheme of the power distribution system lists the number of branches of the main distribution box and the lighting box distribution box on the first floor of the dormitory and the model of the electric energy meter of each branch. In order to meet the needs of intelligent monitoring and remote automatic meter reading, the power management system adopts RS485 bus, and centrally networks 1 ACR230ELH multifunctional power meter installed on the main distribution box AL1 main incoming line, 11 DTSF1352 three-phase rail-type electric meters installed in WL1~WL7 and public bathrooms on each floor, and 108 DDSF1352 single-phase rail-type electric meters installed on each floor of the dormitory building (27×4-story dormitory building). The monitoring center is equipped with monitoring computers, printers, communication servers and necessary auxiliary equipment, and the power management system EMS software is installed to complete the remote collection of each electric energy meter and centralized data processing. The power management system diagram is shown in Figure 5.

Figure 5 System networking scheme

2.3 Functions of power management system

2.3.1 Remote power parameter measurement.

The real-time power parameter collection of the ACR230ELH multifunctional power meter for the main incoming line was completed, including three-phase current, voltage, power, power factor, active power, reactive power, frequency, etc., which are displayed on the main power management screen; the remote automatic meter reading function of 11 DTSF1352 three-phase meters and 108 DDSF1352 single-phase meters was realized; the automatic statistics of daily and monthly electricity consumption and shared energy calculation functions of each dormitory were realized; through the combination of the system and the field instrument, the hierarchical, classified and household metering management of the main incoming line, branches and each end user of the power energy was reflected. See Figure 4. ACR230ELH diagnoses the power quality of the dormitory building, such as current harmonics and imbalance, and the system saves historical records to provide a decision-making basis for the next power quality improvement plan.

2.3.2 Operation status monitoring

The administrator can set the system's collection frequency, such as collecting once every 15 minutes, and set the power load value of each circuit (such as the dormitory load is set to 6~10A). The system can process the collected values ​​according to the settings, and sound and light alarms for overloaded circuits to prompt the administrator of abnormal status information of the circuit. The system can also self-detect abnormal communication of each circuit so that maintenance personnel can conduct troubleshooting and repair in time. [page]

2.3.3 Trend analysis.

Classify and identify the collected electrical parameters and store the necessary parameters in the database. The data storage of all electrical parameters can reach two years, and the data storage of electric energy parameters can reach more than three years. The storage time can be changed according to user needs and hardware configuration. The system provides two curve analysis interfaces: real-time curve and historical trend. The current operating load status of the circuit is analyzed by calling the real-time curve interface of the relevant circuit. The historical trend of the system means that the system can view the historical trend of all stored data, and display various curve screens by calling, which is convenient for engineering personnel to conduct quality analysis on the monitored distribution system. Such as: analysis of the current trend, power trend and harmonic trend of the main incoming line; monthly power consumption trend, bar chart/line chart analysis of the branch circuit, etc., and can also generate a metering database by comparing with the data of the same period of last year/the year before last.

2.3.4 Report printing.

The system can design various types of reports that meet the needs of users according to their needs. Such as: real-time reports, historical reports, event fault and alarm record reports, operation record reports, etc. All data values ​​recorded by the system can be queried and printed, and daily, monthly, quarterly and annual reports of electric energy can be automatically generated. The rate report of electric energy is generated according to the time period of the multiple rate and the set value of the rate. The parameters such as the starting point and interval of the query and print can be set by yourself, and the charging report is automatically generated for internal charging management.

2.4 Project cost

According to the primary plan and system structure, the material name, model, quantity and quotation of the dormitory building power management system are shown in Table 1. The investment excluding labor costs is approximately 114,500 yuan.

Table 1 Unit (Yuan)

serial number	Name	model	quantity	unit price	total
1	Multifunctional power meter	ACR230ELH	1	3000.00	3000.00
2	Three-phase rail type watt-hour meter	DTSF1352	11	1000.00	11000.00
3	Single-phase rail type watt-hour meter	DDSF1352	108	500.00	54000.00
4	Communication cables	RVVP2×1.0	1000	3.30	3300.00
5	Serial Device Server	ACRNET-PORT8	1	6500.00	6500.00
6	Monitoring Computer	DELL brand	1	5000.00	5000.00
7	printer	HP A4 printer	1	1200.00	1200.00
8	Power system software	Acrel-3000	1	30000.00	30000.00
9	Other accessories	Connecting wires, sockets, etc.	1	500.00	500.00
Total		114500.00

3 Conclusion

In January 2009, DDSF1352/DTSF1352 single-phase and three-phase meters passed the inspection commissioned by the National Electric Energy Meter Quality Supervision and Inspection Center (Jiangsu), and all indicators were qualified. In addition to a certain university of science and technology, the product has also been used in a certain cigarette factory in Changsha, a certain central hospital in Yuncheng, and a 9156 project in a certain police district in Shanghai, achieving good social benefits.