Ideas for building ubiquitous power Internet of Things for large urban complexes

China Energy Storage Network News: Wang Xiaobing, Yang Jinshuang, Li Wei, Song Baotong, and Wang Shu, researchers from Beijing Electric Power Economics and Technology Research Institute Co., Ltd. and Tsinghua Sichuan Energy Internet Research Institute, wrote an article in the 2020 Issue 2 of "Electrical Technology" magazine. Based on the characteristics of large-scale urban complexes and the requirements for power supply quality of power grid companies, they analyzed the technical applications of ubiquitous power Internet of Things in large-scale urban complexes in scenarios such as intelligent distribution systems, precise power supply services, orderly shared charging services for electric vehicles, IoT perception, and smart energy comprehensive services, in order to support the informatization and intelligent construction of large-scale urban complexes and the advancement of related technologies to a higher level.

Urban complex is a relatively new concept, which is the result of the accelerating urbanization. Urban complex includes all aspects of modern society and is huge in size, so traditional power grids can no longer meet their needs, and more advanced power grid forms need to be developed. With the increasing maturity of 5G technology, more "smart" cities will be built, which will force power grid companies to change their traditional power supply service concepts and add new technologies and new concepts to the construction of "smart" cities.

Against the backdrop of rapid social development and the explosion of high-tech, State Grid Corporation of China proposed the strategic goal of "three types and two networks" in its 2019 Two Sessions report. Among them, the ubiquitous power Internet of Things, one of the "two networks", in short, is to informatize all aspects of traditional electricity production, transmission, and consumption.

With the vigorous construction of urban complexes, IoT sensing technology will be widely used, which requires that electricity must also be ubiquitous. Therefore, in order to effectively support the vigorous construction of urban complexes, it is necessary to innovate the form of power grids and make smart grids develop in the direction of ubiquitous power IoT.

Figure 1 Ubiquitous Power Internet of Things and Strong Smart Grid

1 Application of Ubiquitous Power Internet of Things in Intelligent Distribution Systems of Large Urban Complexes

As a type of power grid structure, the distribution system is a bridge for the transmission of electric energy between the main power grid and users. The application scenarios of the ubiquitous power Internet of Things in the intelligent distribution system of urban complexes include distribution automation, distribution network hidden danger monitoring, power quality monitoring, load forecasting, etc. Therefore, the ubiquitous power Internet of Things and the distribution system will be deeply integrated, which can be specifically reflected in power supply service command, equipment operation status and online user services.

Figure 2 Application of ubiquitous power Internet of Things in smart distribution system

1.1 Electricity management service

Traditional power operation and maintenance services are basically carried out offline, with users hiring electricians themselves or outsourcing equipment maintenance to engineering installation companies. This method has high labor costs, poor timeliness in repairing equipment failures, and is difficult to participate in market competition without an engineering market foundation.

The power management service refers to the online monitoring of user power equipment through monitoring equipment, and the cooperation with the centralized customer service center to provide online and offline management services for the power distribution equipment of large urban complexes. The online monitoring management service can greatly improve the work efficiency of power professionals, thereby reducing the personnel costs of operating and maintaining power distribution equipment in urban complexes. Through the application of high-level customer service personnel and new technologies, the failure and accident rate of power distribution equipment in urban complexes can be reduced, effectively ensuring the safety and stability of users' power use.

The purpose of electricity trusteeship is to improve the reliability of electricity use for users and meet their needs for safe electricity use. The main work contents include: remote data collection and monitoring, data report management, equipment troubleshooting, regular equipment maintenance, equipment cleaning, inspection and testing, equipment defect management, personnel training, system management, etc.

1.2 User personalized energy service

As the end of the traditional distribution network, the large-scale urban complex distribution system provides other expansive and personalized energy services on the basis of meeting the power supply needs. By establishing good monitoring technology and a good response incentive system, it enables users to be highly involved in the operation of the distribution network, and mobilizes the enthusiasm of power users to participate in the optimized operation of the distribution network.

1) Install power monitoring equipment for users, realize the transmission and interaction of information flow and data flow through the management platform, and generate economical and efficient management and control strategies based on data analysis and calculation to monitor and manage users online, thereby realizing optimal management of energy on the user side and efficient marketing in the energy trading market.

2) Guide users to reduce loads during peak hours, or even reverse output; increase loads during off-peak hours. Through demand response, peak loads or installed capacity can be reduced, the reliability of the energy Internet can be improved, and users can be actively involved in load management, adjust electricity usage, enrich distribution network operation and regulation methods, and improve grid flexibility.

1.3 Orderly shared charging services for electric vehicles

As the number of electric vehicles increases, the overload of distribution networks caused by large-scale centralized charging of electric vehicles has become an urgent problem to be solved. Through the ubiquitous power Internet of Things, orderly charging of electric vehicles in large urban complexes can be achieved, which can be deployed mainly from the following three perspectives.

1) Establish an orderly charging model

(1) Orderly charging model

Orderly charging refers to the use of ubiquitous power Internet of Things technology to conduct sufficient information exchange and hierarchical control between the power grid, users, charging piles and vehicles through energy routers, comprehensively perceive the change trend of distribution transformer load, dynamically adjust charging time and power, optimize the distribution transformer load operation curve, and achieve effective valley filling.

(2) Orderly charging equipment selection

The AC charging pile that supports orderly charging is equipped with an LCD touch screen and an energy router. An independent space for the energy router is designed in the AC charging pile. The LCD touch screen is a human-computer interaction interface. Users can perform corresponding charging operations through the LCD touch screen, and at the same time display charging status, charging parameters and other data to users.

2) Orderly charging control strategy

In the smart energy control system, the orderly charging strategy adopts a hierarchical control method and is implemented in layers by the master station and the energy controller.

(1) Local control strategy of energy controller

The energy controller uses the total load planning curve of the area sent by the master station as a benchmark, combined with the current real-time load information of the area and the real-time charging status of each charging pile in the area, and makes preliminary decisions on new charging applications through the local control strategy algorithm, and arranges a reasonable charging plan; for orders that are in the charging process, the energy controller will give full play to its local autonomy function and formulate an economically reasonable charging plan on the premise of meeting the safe operation requirements of the distribution transformer.

(2) Energy router execution

As the execution device of the charging plan, the energy router sends control instructions such as starting charging, stopping charging or adjusting charging power to the charging pile at a specified time according to the charging plan. When a communication failure occurs, the built-in default charging plan can be executed first, that is, continuous charging with the lowest power, which has a lower priority and will be replaced when the master station or energy controller has a new charging plan input after communication is restored.

3) Innovate orderly charging operation model and incentive strategy

(1) Innovative operating model

Strengthen communication with property management units, sign construction agreements, and conditionally replace orderly charging piles, routers, etc. in customers' private parking spaces or community public parking spaces, and the assets will be uniformly owned by State Grid Electric Vehicle Company. The replacement conditions can be limited to the amount of electricity that customers can participate in orderly charging, shared electricity, etc.

(2) Incentive and guidance strategies

Incentive methods to guide customers to participate in orderly charging and sharing of charging piles include points, red envelopes, etc.

Points incentive: The initial plan is to reward one point for every kilowatt-hour of electricity. Points can be used for value-added services, service fee deductions, etc.