Smart meter technology and market

Smart grid is built on an integrated, high-speed, two-way communication network , and aims to use advanced sensing and measurement technology, advanced equipment technology, advanced control methods, and advanced decision support system technology to achieve reliable, safe, economical, efficient, environmentally friendly and safe operation of the grid . Smart meters are the building blocks of smart grid construction and important information transfer stations for every household. They have far exceeded the simple metering function. In the development of smart grid, smart meters will have a large development space.

1. What is a smart meter?

Smart meter is a new type of fully electronic meter with functions such as electricity measurement, real-time monitoring, automatic control, information exchange and data processing, which can help users to accurately and quickly understand the household electricity consumption and formulate power saving plans. Smart meter is an important basic equipment for data collection of smart grid (especially smart distribution network), which plays an important supporting role in realizing informatization, automation and interaction of power grid. It undertakes the task of collecting, measuring and transmitting original electricity data, and is the basis for realizing information integration, analysis optimization and information display, thereby improving the operating efficiency of power enterprises, promoting energy conservation and emission reduction , and enhancing the stability of power system.

Smart meters are different from traditional meters in that they are two-way real-time communications , interactive, and can provide real-time data, making it possible to implement tiered electricity prices. Therefore, smart meters emphasize stronger information processing, interaction, metering, and communication capabilities in their design . These indicators are also specified in detail in the smart grid standards published by the State Grid Corporation.

Smart meters will change the history of manual meter reading. Workers can understand the user's electricity usage with just a click of the mouse. For users, it will be more convenient to use. Users can deposit a certain amount of electricity bills in the meter in advance, so that they don't have to go to the bank or business hall for a considerable period of time. In addition, users can also transfer money directly from the bank to the meter regularly. And through the information interaction function, users can clearly understand the electricity usage at home. When the balance in the meter is less than a certain value, the meter will remind the user to pay in time.

2. Important applications of smart meters

1. Settlement and Accounting

Smart meters can realize accurate and real-time fee settlement information processing, simplifying the complex process of accounting processing in the past. In the power market environment, dispatchers can switch energy retailers more timely and conveniently, and even realize fully automatic switching in the future. At the same time, users can also obtain more accurate and timely energy consumption information and accounting information.

2. Optimize distributed energy configuration

There are still many problems when distributed energy and distribution networks are connected to the grid. Power supply companies use smart meters to monitor, control and adjust the distribution system in real time, understand the characteristics of distributed power sources and their mutual influence on the operation of the power grid, and optimize the configuration of distributed energy, so as to deliver electricity to end users in the most economical and safest way of transmission and distribution , and improve the reliability of power grid operation and energy efficiency. The use of smart meters can help people give priority to the use of new energy such as wind power and solar energy . The use of real-time data collection and measurement of smart meters to formulate more accurate load forecasts can guide the optimization and dispatch of new energy. The distribution management system platform developed by the University of Hawaii in the United States uses smart meters as portal stations to integrate demand response, residential energy- saving automation, distributed generation optimization management and other functions, and implements coordinated control of the distribution system and the new energy system in the main power grid [1].

3. Distribution network status estimation

At present, the power flow distribution information on the distribution network side is usually very inaccurate, mainly because the information is obtained by comprehensive processing based on the network model, load estimation and measurement information on the high-voltage side of the substation . By adding measurement nodes on the user side, more accurate load and network loss information will be obtained, thereby avoiding overloading of power equipment and deterioration of power quality . By integrating a large amount of measurement data, it is possible to estimate unknown states and verify the accuracy of measurement data.

4. Provide the basis for fault analysis

Power supply companies can use smart meters to monitor users' electricity consumption in real time, realize online analysis of abnormal conditions, dynamic tracking and automatic control, improve power supply reliability, and help achieve preventive maintenance of distribution network components, energy meters and user equipment. When a fault occurs, abnormal power consumption records can be queried through smart meters to provide reliable real-time data for fault analysis. For example, voltage waveform distortion, harmonics, imbalance and other phenomena caused by power electronics equipment failures and grounding faults can be detected. Measurement data can also help power grids and users analyze power grid component failures and network losses.

5. User Energy Management

Through the information provided by smart meters, a user energy management system can be built on it, thereby providing energy management services for different users (residential users, commercial users, industrial users, etc.), while meeting the indoor environment control (temperature, humidity, lighting, etc.), reducing energy consumption as much as possible and achieving the goal of reducing emissions. Some citizens are accustomed to leaving the water heater on for a long time, not turning off the TV power switch when sleeping at night , etc. By checking the power consumption in different time periods, citizens can find out how much power these appliances consume during the time period when they are plugged in but not used.

Provide users with real-time energy consumption data, encourage users to adjust their electricity consumption habits, and promptly discover abnormal energy consumption caused by equipment failures. Based on the technology provided by smart meters, power companies, equipment suppliers and other market participants can provide users with new products and services, such as different types of time-of-use network electricity prices, electricity contracts with buybacks, spot price electricity contracts, etc. Smart meters can accurately measure the electricity consumption of each single appliance such as "washing machines, refrigerators, microwave ovens", and the "power consumption*price" function can warn residents that a certain appliance is a high-energy-consuming appliance during a certain period of time.

6. Smart home appliance control

Smart energy meters have the function of communicating and controlling with smart home appliances, and will become a "stepping stone" for the popularization of remote control home appliances in the future. Smart energy meters can control the start and stop of home appliances by setting parameters according to the real-time electricity price, reduce the load during peak hours, and increase the load during low hours. Without any additional user investment, by changing the use time of high- power electrical equipment, the purpose of saving electricity costs can be achieved, and at the same time, it also contributes to the peak-shaving and valley-filling of the power grid. Residents install "smart interactive terminal" devices at home, connect them to each appliance in the home, and go online to control the home appliances.

7. More convenient payment

Citizens who use a one-card system to pay their electricity bills often find that there is no money in the card or the balance is not enough to offset the deduction when the power company sends a reminder of overdue bills. After the construction of the low-voltage user information collection system, the system can monitor in real time how much electricity each household has used and how much money is left in the card. When the electricity bill paid by citizens in the one-card system is about to run out, the power company will send text messages to remind citizens in time to prevent users from arrears. Citizens who often travel on business often do not know that their families have owed electricity bills or that the arrears have exceeded the payment deadline, which will incur late payment fees. After using a smart meter, the meter will automatically cut off the power according to the conditions agreed upon by the user and the power company, and can be quickly activated after the deduction is re-deducted, without incurring late payment fees.

8. Load remote control

Smart meters can be used to connect and disconnect the entire load, and can also control some users, thereby cooperating with the dispatching department to achieve power control; at the same time, users can also remotely control specific loads through controllable switches.

9. Detection of illegal electricity use

Smart meters can detect events such as meter box opening, wiring changes, meter software updates, etc., so as to promptly detect electricity theft. In areas with high incidence of electricity theft, potential electricity theft can also be discovered in a timely manner by comparing the data of the master meter with the data of all the meters under it.

With the advancement of the information age and the development of technology, smart meters, as the nerve endings of smart grids, will play a greater role in the information society in the near future and have broader application prospects.

3. Development Trend of Smart Meter Technology

At present, the intelligence of smart meters is mainly reflected in the convenience of meter reading and payment, and there is still a long way to go before they can be truly smart meters. In the words of some people in the industry, the current smart meters in China can only be called electronic meters, not smart meters. The biggest feature of smart meters is interaction, that is, the information interaction between users and power supply companies. The key to information interaction is management, which is more convenient and humanized. Humanized management requires stronger information processing capabilities of chips. The development of smart meters must adopt the advanced metering system (AMI), and will inevitably take the direction of modularization, networking and systematization.

1. Adopt Advanced Metering System (AMI)

Smart meters will also move beyond the use of advanced metering infrastructure (AMI) and become part of the future home area network (HAN). AMI refers to the technology of using various communication methods to transmit the customer end meter data back to the control center, and achieve various functions such as remote data reading, provision, setting and control through two-way communication. In addition to improving the shortcomings of traditional manual meter reading, which is uneconomical, inaccurate and not real-time, AMI also has multiple functions, such as supporting various different electricity price rates, providing users with energy usage information and guiding spontaneous energy saving, supporting the transmission of signals for user load control, in order to automatically respond to changes in electricity prices, supporting fault detection and remote on/off management, improving load prediction, and user electricity quality management.

Compared with traditional mechanical meters, AMI has the advantage of two-way communication. Therefore, AMI can connect multiple information such as electricity consumption, power generation and even power storage systems, and assist the power grid to develop into a highway of power system, achieving the function of getting on and off at any time. Therefore, the main advantage of AMI is to promote the realization of energy conservation and carbon reduction goals, improve power supply quality and enhance economic efficiency, so it can provide multiple benefits to the country, the power industry and electricity users.

At the national level, AMI can facilitate demand management and the integration of renewable energy into the grid, thus helping the country achieve its energy conservation and carbon reduction policy goals. For the power industry, AMI can provide load control communication functions, quickly measure and diagnose power quality, and achieve grid self-healing functions (self-healing) to improve power supply quality; and can achieve peak smoothing through the combination of time-of-day electricity price mechanisms to reduce the pressure on new power plants; at the same time, it is easier to obtain users' electricity consumption data, so more innovative services can be provided [2]. Finally, at the user level, AMI with displays can make electricity information transparent, so that users can have more information and conduct energy management; and strengthen the flexible interaction between users and the power system, so that users can play the role of both power generators and power consumers at the same time, which helps to improve the operation of the power market.

2. Modularity

The functional modular design of smart meters has the following advantages: first, the meter can be upgraded by replacing some functional modules without replacing the entire meter, thus getting rid of the fate of batch replacement and elimination caused by the unchangeable design of traditional meters, and even the need to reconstruct the entire system; second, due to the modularization of functions and standardization of structures, the power supply and consumption management department does not have to rely too much on the products of a certain meter manufacturer when purchasing meters, and provides the possibility for standardizing the research and development of meters; third, the method of replacing faulty modules on-site or remotely can be used to improve maintainability and save maintenance costs.

3. Networking

Networking can realize real-time sampling and storage of electric energy data in various occasions, and transmit the information to the power consumption information management system in real time or non-real time through wired or wireless network transmission. Through data sharing and analysis, the power supply and consumption management department can measure and monitor the power consumption information in real time or non-real time. Through networking, some functions of smart meters can be moved from the access layer to the network layer and data management platform layer, and the functions of smart meters can be realized through data sharing and comprehensive analysis, simplifying the design of smart meters. At present, the available communication networks are: power line carrier ( PLC ) network, optical fiber and coaxial cable ( HFC ) network, fixed telephone (PSTN) network, wireless mobile (GSM/GPRS/CDMA) network. Recently, State Grid Corporation of China and China Telecom Corporation signed a strategic cooperation framework agreement in Beijing. The two parties will cooperate in the fields of power grid and communication, focusing on the joint construction of power fiber- to-home projects, and jointly promote the construction of strong smart grids. The power fiber-optic access project technically achieves the goal of only one construction and one channel to solve the problem of cable access to the home at one time, which can replace the previous multiple construction of multiple lines such as electric wires, network cables, telephone lines and cable TV [3]. The purpose of the integration of three networks is to share resources, providing a stable, reliable and low-cost data transmission channel and network for the transmission of power information data, and laying a network foundation for the networking and systematization of smart meters and the realization of automatic meter reading.

4. Systematization

Systematization is the comprehensive use of mature computer technology and power system automation technology to achieve effective analysis, processing and management of massive power consumption data on the data control management platform. Driven by networking and systematization, the power consumption information management system can develop in the direction of distribution and openness, making the expansion of power consumption information management functions more flexible, performance continuously improved, and easier to use.

4. Development prospects of smart meters

1. Domestic market prospects

At present, first-tier cities such as Beijing and Shanghai have already started pilot use. Fuzhou has started to carry out intelligent transformation of power grids for three communities and nearly 257,000 households. The first batch of 3,000 households have officially started to use smart meters, and all 257,000 pilot users will use smart meters in 2010. Nanjing will complete the first batch of 1.02 million households' smart meter transformation free of charge before the end of 2010, and all transformation will be completed within five years.

From mechanical meters to electronic meters, and then to the current smart meters, product upgrades are the current market demand and the direction of enterprise development. In the last century, household meters were mainly mechanical meters, and the price was generally 30 to 40 yuan each. Around 2000, they were gradually replaced by electronic meters, and the price increased slightly to about 50 to 60 yuan each. Today's smart meters have improved their technical content, and the price has doubled compared to electronic meters, more than 100 yuan each.

The market for electric meters is huge. If all electric meters are replaced with smart meters, the market size will be considerable. The number of smart meters installed has started to grow by double digits since 2009, reaching 76 million in 2009 and expected to reach 212 million in 2015. The domestic industry will face a market of more than 5 billion yuan per year, which will be a huge boost to smart meter manufacturers. Smart meter manufacturers will become the vanguard that fully benefits from the construction of smart grids.

2. International market prospects

Europe and North America will remain the main markets in the next five years, while Asia, driven by China, will be the region with the greatest growth potential. Europe and Japan have set a goal of 80% penetration of smart meters by 2020. Global shipments are expected to grow from just a few million units in 2008 to about 50 million units in 2014, with a compound annual growth rate (CAGR) of 48%.

Spain's three power utility companies almost monopolize the entire power market share (Endesa accounts for more than 40%, Iberdrola accounts for more than 30%, Union Fenosa accounts for more than 10%, and the others account for about 4%), with more than 20 million customers. The Spanish government introduced relevant laws in August 2007, requiring that by 2014, all dealers must have an advanced meter management (AMM) operating system, and by 2018, all mechanical meters must be replaced with smart meters, which must be able to achieve active/reactive power measurement, maximum demand measurement, power load characteristics collection, power management , time-of-use billing, remote meter reading, remote power off/on, remote programming and other functions.

The French government is incorporating the use of smart meters by electricity users into law. In 2006, the French power management department proposed three milestone plans: by January 2012, all installed meters must be smart meters; by the end of 2014, 50% of meters must be connected to the AMM system; by the end of 2016, 95% of meters must be connected to the AMM system. In 2006, the Electricity Network Distribution of France ( ERDF ) led an R&D project to serve the needs of power companies and technologies, and planned to replace all 33 million meters with smart meters between 2010 and 2017. Actaris and Landis are conducting a large-scale pilot project of 300,000 smart meters, mainly using PLC communication.

5. Promote the development of smart meters

1. Increase technological innovation

At present, the core technology of smart meters in China is too dependent on imports. In order to promote the sustainable development of China's smart grid, we should first build an integrated scientific research mechanism for smart meters, increase technological innovation, and overcome core technologies and high-end technologies such as chips, electrolytic capacitors, liquid crystal display screens , two-way communication security and control; second, we should deeply analyze the advantages and disadvantages of China's smart meter industry in the international market, identify key project areas such as smart meter wide-area communication technology and smart meter short-distance access communication technology, formulate an international standard roadmap, and actively strive for the right to speak on international standards.

Make full use of the experience accumulated by scientific research institutions such as China Electric Power Research Institute and State Grid Electric Power Research Institute in the process of power system technology research and development, actively learn from the mature technologies of leading enterprises and scientific research institutions in related fields, build a wide range of cooperation platforms, and accelerate the research and development of common technologies and key technology fields. Clarify the research and development focus. In the near future, according to the characteristics and laws of China's power grid development, we should focus on research in the fields of control chips, reliability under complex working conditions, communication interface compatibility, etc., and master the core technology of smart meters as soon as possible [4]. Increase investment in the technical transformation research of existing meters, comprehensively consider functional requirements and R&D and production costs, and improve the economic benefits of smart meter manufacturers.

2. Improve the industrial operation capability of smart meters

First, accelerate the training of talents in the smart meter industry. Smart meters are a cross-industry industry that requires cross-professional and cross-industry talents. Secondly, strengthen technical supervision of electrical products accessing the network, clarify functional requirements and process standards, start from market demand, strengthen standardized design, unify standards, and realize scientific industrialization layout as soon as possible. Third, determine the stage promotion goals. Fully consider the financial burden and operation risks of each stage, follow the overall development goals of each link of the industrial chain, highlight the key points of the stage, and achieve the strategic goals of industrial development in a solid and steady manner.

3. Implement user-side energy management projects

First, we need to increase the research and development of energy management systems, study the specifications of new user-side electrical appliances required for energy management systems, and enrich the types of optimal energy consumption services available to users. Second, the government and power companies need to create conditions, integrate the environment, and provide users with detailed information on energy supply and demand, so as to promote the transformation of users from mere "energy consumers" to "energy managers" and actively choose the optimal energy consumption model.

4. Focus on promotion and popularization

With household users as pilot objects, we will carry out pilot applications of smart meters, focusing on the visualization of power consumption, setting peak and valley electricity prices, and setting time-of-use electricity prices according to temperature changes, and summarize the pilot experience in a timely manner. Based on the cost-benefit analysis of the pilot, we will gradually improve the use of smart meters and gradually popularize smart meters.

VI. Conclusion

At present, the large-scale promotion of smart meters abroad has injected new vitality into the development of the global metering industry. The plan of the State Grid Corporation of China to build a unified and strong smart grid has also brought unprecedented opportunities for the development of domestic metering and electricity information collection equipment and systems. With the acceleration of the construction of smart grids, domestic manufacturers will surely set off a new wave of research and promotion in the field of smart meters. The adoption of various new materials, new technologies, and new processes will also greatly improve the overall level of domestic metering equipment, thereby providing strong technical support for the development of my country's smart grid. In addition, the good social and economic benefits generated by the construction of smart grids should be widely publicized, the relevant government departments should be more aware of smart meters and their development significance, and actively strive for fiscal and taxation policies and industrial policy support.