Recently, the Beidou signal “router” developed by the State Grid Jiangsu Electric Power Research Institute was put into maintenance operation at the Wuxi 220 kV Shuanghe Substation, providing accurate differential positioning data for the Beidou terminal installed on the crane, achieving centimeter-level positioning for the crane.
The Beidou differential positioning technology can provide centimeter-level high-precision positioning services for electrical equipment. Due to stringent network security requirements and high access costs for power grid companies using Beidou differential positioning technology, its application in the power business is limited. To address this, the Jiangsu Electric Power Research Institute innovatively developed the Beidou signal “router.” This device features three functions: differential positioning data sharing, base station services, and anti-spoofing signal detection. Each device can cover an area of up to 1.2 square kilometers, providing centimeter-level positioning services for more than 200 Beidou terminals.
The Power Industry Needs High-Precision Positioning Functions
Currently, the Beidou Satellite Navigation System (BDS) has been fully applied in various industries. Conventional Beidou positioning technology uses satellite signals for positioning with an accuracy of meter-level, which can meet the navigation and other life application needs. However, in some business applications within the power industry, meter-level positioning accuracy is insufficient.
“We urgently need higher positioning accuracy to better ensure power supply reliability and operational safety, with a positioning deviation ideally less than 10 centimeters.”
said the leader of the IoT team at Jiangsu Electric Power Research Institute’s Digital Technology Center.
At present, centimeter-level high-precision positioning mainly relies on Beidou differential positioning technology. Pre-set Beidou reference stations publish differential positioning data, “informing” surrounding Beidou terminals how to correct their positioning coordinates, allowing Beidou terminals to refine their positioning accuracy to the centimeter level.
The Jiangsu Electric Power Research Institute began researching the application of Beidou differential positioning technology in the power industry in 2020, leading the development of six high-precision electric power Beidou business terminals and establishing a performance testing experimental site for electric power Beidou terminal products. They also participated in the construction of the State Grid Jiangsu Power Beidou Ground Enhancement Network.
In early 2021, the Jiangsu Electric Power Research Institute conducted research in Nanjing Jiangbei New District, Wuxi, and other locations to investigate the application needs of Beidou technology in the power industry, finding that Beidou differential positioning technology could effectively enhance the safety of transmission corridor inspections, but technical promotion was constrained. In substations and key transmission corridors, multiple Beidou terminals often work simultaneously. Each Beidou terminal must be equipped with a remote communication module that meets power safety requirements and obtain authorization information for differential positioning services to connect to the Beidou system. These communication modules have high power consumption, requiring larger capacity batteries, which increases the size, weight, and cost of the Beidou terminal. Each Beidou terminal needs to be set up for network and differential positioning services, posing certain difficulties in engineering applications.
To solve these problems, the research team embarked on a path of innovation.
Beidou Signal Router Successfully Developed
Question 1
Most Beidou business applications in the power sector are concentrated in one area. Is it possible to obtain differential positioning data in real-time and share it with other Beidou terminals in the area?
If this solution is feasible, it would allow for low-power, miniaturized terminals that require no setup, significantly reducing usage costs. Therefore, solving the problem of sharing differential positioning data became the main focus of the research team.
Can we develop a Beidou “router”?
In 2022, the research team began exploring Beidou differential positioning data sharing technology. During a brainstorming session, a router placed on the conference table inspired the team’s creativity. “Can we develop a Beidou ‘router’ that uses the communication network of the power IoT perception layer to distribute differential positioning data, allowing multiple terminals to share one data set?” the team leader proposed.
Question 2
The research team first studied the interaction protocol between Beidou terminals and the electric power Beidou system, and combined recent research results in power IoT technology to build a prototype system for sharing Beidou differential positioning data, conducting experiments to test the impact of using the same data on the positioning performance of multiple Beidou terminals within an area, and testing the performance of different IoT communication technologies.
After nearly a hundred tests and parameter adjustments, the research team achieved real-time acquisition of differential positioning data from the electric power Beidou system and sent it to Beidou terminals using a local low-power wireless network. This way, other Beidou terminals do not need to have remote communication capabilities; they only need to use a local low-power wireless communication unit as a data sharing device to achieve high-precision positioning. This device acts like a Beidou signal “router,” distributing differential positioning data.
To ensure that positioning is not affected when the network is poor or the differential signal is weak, the research team developed an automatic base station switching function. The Beidou signal “router” will verify its coordinates in real-time to determine whether the differential positioning data from the electric power Beidou system is normal. If an anomaly occurs, the device can automatically switch to base station mode, using its accurate coordinates to calculate local differential positioning data, providing local differential positioning services for Beidou terminals. The device can also determine whether there are abnormal satellite positioning signals nearby based on real-time positioning and issue warnings to prevent spoofing signals from affecting the normal operation of Beidou terminals.
The research team used authentication access and data encryption technologies in the local wireless communication network, allowing the Beidou signal “router” and Beidou terminals to connect through an encrypted network, ensuring the secure transmission of differential positioning data and Beidou terminal location data.
Both a Router and an IoT Gateway
As the scale of electrical equipment expands and the demand for intelligent perception increases, the number of Beidou terminal applications is increasing. A substation can deploy more than 100 terminals. Achieving accurate positioning of terminals and managing terminal location data has become a challenge.
Since August 2022, the research team has developed a cloud-edge interaction interface for the power IoT, enabling the Beidou signal “router” to add edge IoT proxy functions, achieving “one device with multiple uses.” This device not only functions as a Beidou signal “router” but can also serve as an IoT gateway, reporting the location data of Beidou terminals to the State Grid Jiangsu Electric Power IoT management platform.
“Operation and maintenance of transmission lines and substation work face challenges of numerous terminals and varying locations,” the team leader explained. “The Beidou signal ‘router’ can play a role in terminal positioning and location reporting in these scenarios.”
On November 14, 2022, the device was deployed in the Jiangsu Electric Power Research Institute campus and underwent reliability testing. During a half-month online testing period, the device operated stably. On November 29, 2022, the device was piloted in the 3D control project for crane operations at the Wuxi 220 kV Shuanghe Substation, preventing the crane from being too close to live equipment and ensuring safety monitoring throughout the crane operation process.
The application of the Beidou signal “router” has reduced the usage cost of Beidou differential positioning technology, providing a replicable, scalable, and low-cost application solution for the application of “power + Beidou” technology, which will be promoted in substations and transmission corridors across Jiangsu Province.
Contributors: Xu Jiangtao, Ye Dizhizhuoran
Editors: Sun Xiaohan
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