With the help of a self-developed electricity information collection system model, the research and development team of the Institute of Metrology of China Electric Power Research Institute recently conducted a real-time sensing test of intelligent energy meters, providing technical support solutions for the entire chain of power grid marketing business based on the test results.

Currently, State Grid Corporation of China has installed over 612 million smart energy meters in its operating area, and has achieved real-time and accurate perception of large-scale smart energy meter data, providing more efficient power supply services for the majority of electricity customers. Based on independent innovation, China Electric Power Research Institute has developed an electricity information collection system suitable for large-scale promotion and application through deep integration of industry, academia, research and application, and has developed efficient testing methods for the system. At present, relevant technological achievements have been widely applied in the research and manufacturing process of dual-mode (HDC) communication units, intelligent measurement terminals, standardized verification and inspection equipment, main station systems and other related equipment, involving all provincial power companies and more than 100 equipment manufacturers in the operating area of State Grid Corporation of China, with significant economic and social benefits.

Realize comprehensive support for marketing business

On May 24th, the research and development team of the Institute of Metrology of China Electric Power Research Institute collaborated with the Marketing Service Center (Metrology Center) of State Grid Shandong Electric Power Company to conduct high-speed communication channel efficiency testing in Jinan, to verify the real-time and reliability of high-speed channel transmission.

The communication channel is the pathway for data transmission. In 2009, State Grid Corporation of China constructed an electricity information collection system and introduced narrowband power line carrier technology to support the transmission of power data communication channels. Narrowband power line carrier frequencies range from 3 kHz to 500 kHz, with low data transmission rates and poor carrier channel environments. With the gradual deepening of the application of electricity information collection systems, the scope of marketing services carried by the systems continues to expand, requiring dual-mode communication technologies that cover high-speed power line carriers and high-speed wireless to help improve the transmission capacity of communication channels.

The research and development team has designed a high bandwidth and high electromagnetic interference resistant communication channel physical transmission layer through joint research and development of dual-mode communication technology, solving the reliability problem of power line information exchange.

In the physical transmission layer of the communication channel, we have designed four working frequency bands, and the point-to-point communication rate has been increased to over 1 megabit per second, which is equivalent to building a 'highway' for data transmission. We propose a method for channel interleaving and diversity copy processing in both time and frequency domains, and have developed a dual-mode communication unit to eliminate key hidden dangers such as noise interference, multipath, and fading in power line channels. "said Li Ran, a researcher at the Electric Information Acquisition Equipment Experimental Research Laboratory.

Based on the power user side data obtained from the dual-mode communication unit, the research and development team has also established analysis models for marketing businesses such as electricity theft analysis, fine line loss analysis in the substation area, intelligent cost control, orderly charging of new energy vehicles, and distributed energy access, to support marketing businesses.

Starting from 2021, the research team has collaborated with 19 communication equipment integration enterprises for household electricity information collection systems to mass produce dual-mode communication units. After the transformation of technological achievements, the first batch of tested communication units were used for provincial power companies such as State Grid Tianjin, Hebei, and Chongqing Electric Power. In 2022, dual-mode communication units will be promoted and applied in all provincial-level power companies within the State Grid operating area. As of now, provincial power companies have installed a total of 87.15 million dual-mode communication units.

Improve the efficiency of power quality monitoring

On June 3rd, during the operation test of the energy consumption information perception data fusion system model, the research and development team initiated a collection task using a simulated main station vector measurement terminal. The measurement terminal read the voltage and current data of the energy meter 100 times within 1 minute.

The measurement terminal is an important device that connects the intelligent energy meter and the main station for collecting electricity information. It is mainly installed next to the transformer and used to collect data from the intelligent energy meter and schedule tasks in the power supply area. In the past, the processing capacity of measurement terminals was insufficient and their functions were relatively single. In the construction of new power systems, the number of terminal nodes in the power grid will experience explosive growth, and the objects collected by measurement terminals will become more diverse and the collection methods will be more flexible, which will put forward new and higher requirements for the performance of collection terminals.

The research team for electricity information collection equipment testing focuses on the functions, types, structures, technical parameters, and other aspects of intelligent measurement terminals to study and construct a new generation of intelligent measurement terminal technology standard system. The team adopted a modular and scalable design approach to optimize the hardware layout of the power management unit, cross sampling, core board, fixed peripherals, etc. The main frequency of the measurement terminal was increased to 1 GHz, and the storage capacity was increased from 64 megabytes to 8 gigabytes, expanding the terminal's functions such as cross sampling, computation, and storage.

In terms of cross sampling function, the new generation of intelligent measurement terminals realizes integrated data collection and monitoring between stations and areas; In terms of computation and storage, the measurement terminal recorded and processed 2.584 billion daily electricity data, improving the working conditions of weak batch task execution ability and poor business scalability. At present, the team has signed agreements with more than 70 domestic collection terminal manufacturers, and will invest in the application of about 20 million intelligent measurement terminals in the future.

Expand the application scenarios of intelligent IoT

In July 2023, the intelligent IoT energy meter equipped with orderly charging modules will be piloted for the first time in the Pan Asian Games area of Hangzhou. At present, 200 sets of orderly charging equipment for electric vehicles have been installed in the region. The electricity information collection system collects real-time data on the load of distribution transformers and the number of connected electric vehicles in the community, excavates the remaining capacity of distribution transformers in the area, and forms a 1.4 megawatt adjustable load resource pool, reducing capacity expansion pressure and improving asset utilization.

With the transformation and upgrading of traditional power systems to new power systems, intelligent energy meters not only play a fundamental role in energy metering, but also serve as key equipment hubs for customer side power generation and consumption equipment, playing a role in equipment control, information exchange, and interconnection.

The research and development team has designed and developed an intelligent IoT energy meter with hardware modularization and software APP for intelligent IoT application scenarios. On the premise of ensuring stable and reliable basic measurement functions, this meter also has functions such as wide range accurate measurement, distributed large capacity storage, diversified and efficient communication, intelligent display, and abnormal perception monitoring. It realizes extended applications such as distributed photovoltaic monitoring, smart energy consumption of residential households, electric vehicles, and distributed energy services, solving the problem of hardware solidification and single function of electric energy meters, and meeting the construction needs of different business scenarios. At present, the technological achievements of intelligent IoT electric energy meters are widely used in more than 80 intelligent electric energy meter manufacturing enterprises, covering 27 provinces (regions, cities) including Hebei, Chongqing, and Ningxia, effectively supporting the construction of new power systems and enhancing the overall level and international competitiveness of China's intelligent electric energy meters.

Building a "1+27" integrated operation mode for the collection main station

The new generation of electricity information collection system (Collection 2.0) of State Grid Corporation of China is one of the most important basic data sources for the company. The system was established in 2009 and is capable of collecting and remotely controlling electricity for all high and low voltage users. By 2017, it had achieved "full coverage and collection" for all types of users. With the continuous emergence of various emerging businesses, the "dual carbon" target and spot trading have given rise to new business scenarios. The transformation and upgrading of service models for power grid enterprises have put forward higher requirements for the frequency, quality, and application effectiveness of data collection systems.

The State Grid Marketing Department conscientiously implements the deployment of State Grid Corporation of China and actively organizes the construction of Data Collection 2.0. As of now, all 27 provincial-level power companies have launched the 2.0 system online and achieved a two-level "data+business" integration with the headquarters level platform, building a "1+27" integrated operation mode.

The new generation of electricity information collection system focuses on using emerging technologies such as big data storage, batch flow calculation, and micro application microservices, building a two-level integrated operation system of 'headquarters province', and creating a new type of business application with microservices as the core. This not only significantly enhances the system's scalability, but also greatly improves the overall performance level, "said Dou Jian, a researcher in the metrology and testing technology research and development department.

After the system is built, the project construction team relies on the "headquarters province" two-level communication channel, focusing on core businesses such as archive assets, electricity analysis, cost control execution, key user monitoring, low-voltage distributed photovoltaic regulation, power outage monitoring, etc., to construct an interactive data mining model, carry out network level data monitoring and analysis applications, and effectively support marketing business control and refined management.

At present, Collection 2.0 has cumulatively connected 612 million smart energy meters and over 67 million collection terminals, with a user coverage rate of 100% and a collection success rate of 99.49%. It has achieved energy collection and remote cost control for all high and low voltage users, with a daily data increment of over 14 terabytes. It shares more than 1 billion pieces of raw collected data and over 400 million pieces of statistical analysis data with multiple professional departments and more than 20 external business systems every day, effectively supporting more than 40 core businesses of the company and laying a solid data foundation for the digital transformation of the power grid.