A brief discussion on the solution of enterprise energy monitoring and management system

1 Overview

In China's energy consumption, industry is the largest energy consumer, accounting for about 70% of the total national energy consumption. The "Proposal of the CPC Central Committee on Formulating the Eleventh Five-Year Plan for National Economic and Social Development" proposed that the energy consumption per unit of GDP at the end of the "Eleventh Five-Year Plan" period should be reduced by about 20% compared with the end of the "Tenth Five-Year Plan". This indicator is one of the most important binding indicators in the "Eleventh Five-Year Plan" and is also the goal of energy conservation work during the "Eleventh Five-Year Plan" period. Therefore, strengthening the energy measurement management of enterprises, carrying out energy-saving and consumption-reducing actions in enterprises, and improving energy utilization are the most effective ways to reduce resource consumption and protect the environment. It is also an important part of China's new industrialization path. This is of great significance for improving the economic benefits of enterprises, alleviating the energy and environmental constraints faced by social and economic development, and achieving the goals of the "Eleventh Five-Year Plan".

In order to enable enterprises to better complete resource allocation, production organization, department settlement, and cost accounting, it is necessary to establish an effective automated energy data acquisition system to monitor energy supply so that enterprises can grasp the energy status in real time, lay a solid data foundation for realizing energy automation regulation, and facilitate the measurement and cost accounting of enterprises.

Energy data is standardized, professional, scientific, and time-sensitive, and is difficult to collect. At the same time, considering the importance of energy data to corporate decision-making and the dangerous nature of energy itself, higher requirements need to be placed on the energy data acquisition system established by the enterprise. Therefore, the enterprise energy management system (hereinafter referred to as EMS) must meet the requirements of strong professionalism, good real-time performance, remote data exchange, and strong availability.

2 The current situation and needs of enterprise energy management

Enterprises recognize the importance of data for enterprise management, and use various instruments and meters to collect energy data, and send special personnel to perform on-site maintenance and copying of instruments, meters, and collected data, and statistics and reports step by step, and establish a database to manage the data. The disadvantage of this is that manual operation is inefficient and cannot meet the needs of large-scale data collection. Therefore, the establishment of an enterprise energy management system is of great significance to deepening enterprise management and maintaining the normal operation of the enterprise.
For an enterprise, the installation scope of the enterprise energy management system includes the data collection of the water supply consumption of the main plant (whether it is groundwater or urban pipe network water supply), real-time data collection of water supply pressure, water temperature, etc., water supply consumption data collection of each branch, data collection of other related independent accounting departments, etc. Product output collection of each branch, etc. Real-time supply data collection of power branch, real-time data collection or registration of various energy products produced by power branch, etc. Supply data of the main plant of various other energy sources and supply data of each independent accounting unit are collected or recorded.

Since enterprise energy management is a complex and huge computer information system. This requires strong support from the perfect enterprise local area network (Intranet) system within the enterprise. As far as the current status of various enterprises is concerned, basically their internal Intranet has been established, and various application systems established on the internal LAN system of the enterprise are also gradually being improved. The enterprise energy management system is an application system established on the internal LAN system of the enterprise. It needs to be closely integrated with other application systems of the enterprise (such as the internal office system of the enterprise) to coordinate and complete various tasks.

Since the energy management system involves a wide range, a large number of quantities and categories, the communication protocols used are inconsistent, the metering equipment used by each enterprise is also very different, and the different energy systems of each enterprise and branch workshop are also different. Therefore, we adopt a unified management interface and a separate collection method. We will introduce it in detail in the following system structure.

3 Comprehensive description of enterprise energy management system solution

3.1 Introduction to solution design

The enterprise energy management system developed by Acrel Company, field data collection is based on the network power meter independently developed by Acrel. In terms of information transmission, it realizes information exchange and inspection service system based on Acrel-2000 system. In this way, each application program of the enterprise obtains the key data subscribed by each other, which can greatly improve the efficiency of data processing.

Energy data includes three types: energy supply status data, energy supply hourly data, and energy supply cumulative data. Each type of data has a different application scope. The energy supply status data is the basis of all data. The other two types of data are obtained through instruments, meters, manual entry or calculation programs, and are key data required by other application systems. Therefore, Ankerui's energy data acquisition system can extract key data required by other applications while capturing energy supply status data, and actively send it to various applications to meet the office and processing needs of various departments, and meet the needs of settlement and decision-making while monitoring.

3.2 Overall design principles

In view of the current level of energy data acquisition systems at home and abroad, we put forward the following design principles for enterprise energy management systems:

◆Adopt advanced, mature and practical technologies

At present, the development of energy data acquisition system technology has been relatively mature. What we are planning now is a system facing the 21st century, which must stand the test of the times. Therefore, we should pursue advanced technology, simple and practical use, and mature and reliable technology without any experimental application.

◆The system should have centralized and unified management capabilities to greatly facilitate system management

According to the actual management system, public safety management is centralized and unified. Therefore, our system has a multi-level centralized and unified management center, and implements scientific and reasonable management to make the monitoring technology play the highest effect.

◆The system should be open, scalable, compatible and flexible.

With security as the core, the system should be open and be able to connect with other systems organically and integrate into a whole. The size of the system varies greatly, requiring the system to be suitable for a variety of scales and have strong scalability; it should be able to adapt to the system expansion requirements at any time. The system has strong compatibility and flexibility, and can adapt to product upgrades, which is an important idea in system design.

◆The design of the system and the selection of products should be standardized and normalized. The design of the system and the selection of products should be standardized and normalized.

◆The system must be safe, reliable and fault-tolerant.

The safety and reliability of system equipment is a very important indicator. In order to avoid operator misoperation, etc., which causes the system to work abnormally, the system is required to have strong fault tolerance and self-test functions.

◆Reasonable performance-price ratio When designing the system, we should start from reality and pursue the highest performance at a limited price. [page]

3.3 Composition of system modules

System network topology diagram

The above figure is the network topology of Acrel-2000 power monitoring system. The enterprise EMS mainly consists of the following subsystems (SubSystem) that can run independently:

Data browsing and entry system: The main functions of this system are as follows: 1. Publish real-time energy data to the enterprise intranet web and generate various reports, curves, charts, etc. Provide scientific basis for various relevant departments and enterprise decision-making levels. 2. Manual entry of energy data. For some monitoring points that are not set up for automatic collection, the meter reader of the instrument is required to enter the instrument data from the system at a fixed time. This function is also applicable to enterprises with insufficient funds and few automatic monitoring points. For
other manual monitoring points that require a large amount of capital investment for transformation, manual entry can be adopted. In this way, while reducing capital investment, various energy data can be managed in an informationized manner to the maximum extent. At the same time, when the enterprise needs it, real-time energy data can be published to the external network (Internet) through the enterprise computer security management network for remote browsing by authorized enterprise personnel. In order to ensure data security, energy data is generally not allowed to be entered and modified by external network personnel.

Data acquisition system: It mainly completes the real-time collection and reporting of energy data. This system is the main source of enterprise energy management data. All important status data required for enterprise energy management must rely on Acrel's reliable data acquisition terminal INDTU-051G/10. The acquisition system is mainly composed of a central receiving server and a lower-level acquisition terminal. INDTU is connected to the metering instrument via RS232/485 to obtain real-time data, and then sends the real-time data to the central data receiving server through the mobile GPRS network or the factory intranet. Since INDTU uses an embedded operating system, it has strong computing power and openness. And it has built-in information automatic acquisition components, which can actively report information to the network according to information changes, replacing the traditional database round-robin, ensuring real-time data transmission while greatly reducing network data communication volume and the burden of the central server, ensuring the stability and reliability of the central server. At the same time, INDTU has a built-in storage optional module, which can save data for a certain period of time according to user needs to ensure that data will not be lost when the communication link fails. The integrity and continuity of the data are guaranteed to the maximum extent.

Data middleware: This system mainly completes the acquisition of required data from other companies' existing MIS systems or monitoring systems, and imports them into the enterprise energy management system database for use by the energy management system. The data middleware will not affect other existing systems. It only reads the information required by the energy management system from the existing system of the enterprise, and does not write any information to the system.

Therefore, the data flow of the system is unidirectional, which can fully guarantee the security of other existing systems. According to the different systems that need to obtain data, different data middleware needs to be customized and developed to meet the needs of the enterprise. At the same time, different application systems can provide different data acquisition methods, which need to be treated differently and processed separately.

Energy management system application: This subsystem is mainly provided to various applications of the enterprise energy management system to share the results brought by energy informatization. The system mainly consists of two parts, application publishing server and energy management client. The application publishing server mainly publishes various energy management data to other application systems of the enterprise, such as the financial management system. Other applications mainly obtain different data according to their subscriptions. The energy management client mainly completes various initializations of energy management, addition and deletion of collection points. Data statistics and accounting of the main plant and branch plants. Data monitoring, alarm, increase and decrease of web publishing data at each collection point, management and allocation of various personnel permissions. Generation of various daily reports. Generation of various data curves, pie charts, bar charts, etc.

3.4 System Features

This system adopts distributed deployment to give full play to the computing power of each component, and maximize the system performance and processing speed. The advantages and benefits are also reflected in several aspects:

◆ Stability and openness are taken into account. INDTU has the characteristics of strong environmental adaptability and can be deployed in harsh environments to meet the needs of instrument and equipment data acquisition. The system is stable and can work continuously for a long time without on-site maintenance;

◆ High real-time performance. Small communication volume. Due to the use of active data reporting, the network communication volume is greatly reduced, while the real-time accuracy of the data is guaranteed.

◆ The subsystems are independent of each other and have weak dependence. The subsystems of this system are independent of each other, can form their own systems, and can be built in stages and batches. Whether it is web data browsing and input or real-time data collection, they are independent of each other and are related to each other through the enterprise database. Therefore, each enterprise can build in batches and at different times according to its own situation to minimize capital investment.

◆ High return on system investment. The system fully utilizes the computing power of all subsystems, allowing the center to focus on receiving and distributing data. On the basis of ensuring efficiency and effectiveness, it reduces the demand for hardware and can reduce the company's investment in hardware. And when there are many collection points and a large amount of data, the system can be conveniently distributed and clustered, and this deployment can also fully guarantee the stability, security, and economy of the system; and the relational database is only used to store data that meets the needs of historical queries, settlements, accounting and other applications, which can also greatly improve the service efficiency of the database;

◆ Strong application expansion capabilities. With the continuous extension of applications, the scope of enterprise data needs will continue to expand. The system can easily realize data exchange between different hardware and software platforms, and can fully meet the different needs of enterprises for information services in different development periods. [page]

3.5 Main monitoring and metering instruments

(1) For high-voltage circuits or low-voltage incoming line circuits, select ACR330ELH meter.

This meter is a power quality analysis instrument with the following main functions: LCD display, full electrical parameter measurement (U, I, P, Q, PF, F, S); four-quadrant power metering, multi-rate power statistics; THDu, THDi, 2-31 harmonic components; voltage crest factor, telephone waveform factor, current K factor, voltage and current unbalance calculation; grid voltage and current positive, negative, zero sequence component (including negative sequence current) measurement; 4DI+3DO (DO3 has overvoltage, undervoltage, overcurrent, unbalance alarm); RS485 communication interface, Modbus protocol or DL/T645 protocol. Dimensions: 120×120mm, opening size: 108×108mm. Suitable for high-voltage important circuits or low-voltage incoming line cabinets.

(2) For low-voltage contact or outgoing line circuits, select ACR220EL power meter.

The main functions of this meter are: LCD display, full electrical parameter measurement (U, I, P, Q, PF, F); four-quadrant energy metering, multi-rate energy statistics, maximum demand statistics; 4DI+2DO; RS485 communication interface, Modbus protocol. Dimensions: 96×96mm, opening size: 88×88mm. Suitable for low-voltage contact cabinets and outgoing line cabinets.

(3) For power cabinets and lighting boxes, select ACR120EL power meter or rail-type meter.

The main functions of ACR120EL power meter are: LCD display, full electrical parameter measurement (U, I, P, Q, PF, F); four-quadrant energy metering, multi-rate energy statistics, maximum demand statistics; 2DI+2DO; RS485 communication interface, Modbus protocol. Dimensions: opening size 80×80mm, opening size 72×72mm. Suitable for power cabinets.

DTSD1352 rail-mounted electric meter main functions: LCD display, full electric parameter measurement (U, I, P, Q, PF, F, S); four-quadrant electric energy measurement, multi-rate electric energy statistics, maximum demand statistics; current specifications 1.5 (6) A, 5 (20) A, 10 (40) A, 20 (80) A optional, RS485 communication interface, Modbus protocol or DL/T 645 protocol optional. Dimensions: 126 × 89 × 74 mm, 7 modules. Suitable for power cabinets.

Main functions of DTSF1352 rail-mounted electric meter: current specifications of 1.5(6)A, 5(20)A, 10(40)A, 20(80)A are optional, multi-rate electric energy statistics, electric energy pulse output, RS485 communication interface, Modbus protocol or DL/T 645 protocol are optional. Dimensions: 126×89×74mm, 7 modules. Suitable for three-phase electric energy measurement in lighting boxes.

Main functions of DDSF1352 electric meter for lighting boxes: current specifications of 1.5(6)A, 5(20)A, 10(40)A, 20(80)A are optional, multi-rate electric energy statistics, electric energy pulse output, RS485 communication interface, Modbus protocol or DL/T 645 protocol are optional. Dimensions: 76×89×74mm, 4 modules. Suitable for current and voltage measurement in lighting boxes; single-phase electric energy measurement.

(4) ARTU-P32 remote pulse unit

The ARTU-P32 remote pulse unit is used to collect electrical or non-electrical energy, such as oxygen, water, and gas pulses.

4 Energy data classification and form

The energy data of the EMS system is divided into primary energy and secondary energy according to the source.

Primary energy refers to the energy obtained by the enterprise from the outside. For example, water, electricity, steam, coal, coal gas, natural gas, gasoline, diesel, etc. The enterprise itself cannot produce primary energy and needs to obtain it from the outside. In order to obtain this energy, it needs to pay the corresponding cost.

Secondary energy refers to the energy produced by the enterprise itself. For example, pure water, compressed air, nitrogen, chilled water, cooling water, heating water, etc. This energy is the energy generated by the enterprise through secondary processing of primary energy through its own power workshop or branch plant. The production of secondary energy requires the consumption of the enterprise's primary energy and labor costs. At the same time, the secondary energy is supplied to other production departments of the enterprise. However, for each accounting unit of the enterprise, the energy consumption of each department must be independently calculated. Including primary energy and secondary energy.

EMS system is divided into liquid medium, gas medium and electric energy according to energy form. Liquid medium: such as industrial water, domestic water, soft water, industrial oil, petroleum, diesel, chemical liquid, etc. Gas medium: such as blast furnace gas, coke oven gas, converter gas, industrial gas, compressed air, argon, oxygen, nitrogen, steam, natural gas, etc.; Electric energy: such as 380V power electricity, 6KV high voltage, 110KV high voltage and other specifications of voltage, current, frequency and other electrical quantities and the operation of various power equipment, etc.; Energy data is mainly divided into three types of data according to the supply form: energy supply status data, energy supply hourly data, and energy supply cumulative data. Energy supply

status data mainly meets the needs of real-time monitoring. Generally, the collection frequency is high and there is no need to save historical data for a long time. For example, real-time steam temperature, pressure and other data. This data mainly completes the enterprise's real-time monitoring of energy quality and timely adjusts the quality of energy supply. Generally, there is no need to save every data in real time.
Energy supply hourly data is for management and measurement purposes, mainly recording the status value or cumulative value of energy supply at the hour. It has the characteristics of low collection frequency and high time accuracy. As the basis for management, measurement and settlement, it must be saved.

The energy supply accumulation data is the accumulation of energy supply values ​​over a period of time. It mainly provides data basis for decision-making and accounting. It is an important data concerned by enterprise leaders' decision-making and enterprise financial accounting. It is of great significance to maintain the normal operation of the enterprise and must be saved.

5 Enterprise Energy Management System Software Structure

Enterprise energy management consists of the following functional software. Each software is independent of each other, and each software system is closely integrated through the database. At the same time, the normal operation of other software will not be affected by the failure of a certain software.

◆WEB browsing and input system software
◆Wireless data receiving software
◆DTU collection software
◆Data import middleware
software ◆Energy management client software
◆Energy management interface gateway

6 Conclusion

This solution is a brief introduction to some basic conditions of our company's energy management system. Compared with the user's existing collection and energy management system, it has the characteristics of low investment, high efficiency, high degree of informatization, and stable and reliable system. Under the trend of energy saving and consumption reduction in China, the enterprise energy management system will surely bring considerable benefits to the enterprise.

References
[1] Shanghai Ankerui Electric Co., Ltd. Product Manual. 2010.08 Edition.
[2] Shijiazhuang Yibang Technology Co., Ltd. Product Information.