Digital Engine Empowers Smart Grids

[July 9th, 2020]New Information and Communications Technologies (ICT) — such as big data, cloud computing, Internet of Things (IoT), mobile Internet, and Artificial Intelligence (AI) — has developed rapidly since 2013, paving the way for the transformation of power grids. Indeed, using data as the main development engine, electric power companies have enhanced intelligent applications across multiple grid domains. Making use of digital capabilities to mitigate risks and seize new opportunities has become a common pursuit in the industry.

New ICT Promotes High-Quality Development

As digitalization becomes the new norm in the industry, people's expectations for technology application have also increased.

"All industry players are thinking about how to adapt to these new trends and overcome challenges using new technology. ICT and digital transformation are, without a doubt, playing a pivotal role right now," said Jack Chen, Director of the Energy Marketing and Solution Sales Department of Huawei’s Enterprise Business Group.

An increasing number of electric power companies are now identifying digital transformation strategies as their first priority. Through transformation, companies are building unified digital platforms to manage their massive amount of internal operations systems as well as using their existing data and resources to grow their business.

The partnership between Huawei and the State Grid Corporation of China (SGCC) is a real-world example where a digital platform, an IoT platform, and a cloud platform are all deployed. These cutting-edge technologies enabled SGCC to provide daily business recovery indexes through big data, even during the pandemic. With big data such as this, the government was able to accurately assess the real-time employment situation of industries in different cities. Elsewhere, the State Grid Henan Electric Power Company — one of SGCC's provincial branches — used to spend four hours collecting and storing data before Huawei's solution was implemented. Now, the whole process takes just 30 minutes, providing far more efficient services for both internal and external users.

Electric power companies have also invested heavily in the Operations and Maintenance (O&M) of transmission lines to ensure transmission quality. Manual inspection of transmission lines is not only inefficient and but also high risk. To tackle this problem, Huawei successfully embedded AI modules into cameras and drones in a joint innovation made with China Southern Power Grid (CSG). With the help of AI, O&M teams can monitor transmission lines remotely through drone cameras, which send back images or video footage of faults, helping O&M personnel effectively detect faults and risks. This has significantly reduced the bandwidth required and increased O&M efficiency. The Shenzhen Power Supply Bureau reduced its grid inspection time from 20 days to just two hours, with the amount of time required for image capture falling from hours to minutes. Image analysis accuracy stands at 90%.

Two major challenges in the power industry are predicting renewable energy yield and integrating renewable energy into the power grid. Here, cloud and big data technologies can help. They improve grid O&M efficiency along with the customer experience, and also effectively enable renewable energy generation. To integrate more clean energy into the grid, the State Grid Qinghai Electric Power Company worked closely with Huawei to construct a new energy data center with AI and big data capabilities, and deploy power storage systems within power plants. The new systems allow the company to better predict the renewable energy yield, based on the weather forecast, and with multi-energy compensation, the total power output able to access the grid has become more stable. Indeed, in 2019, Qinghai province was able to maintain 100% renewable energy generation for 15 consecutive days.

The rapid development of distributed clean energy has resulted in changes to the grid structure. Traditionally, the energy flow from a power plant is transmitted, transformed, and distributed to consumers. However, in the future, this model will be transformed. For example, an Electric Vehicle (EV) will not only consume energy; it will also store it and supply power back to the grid when the tariff rises sufficiently high. In such scenarios, the synergy of energy, information, and business flows will be of paramount importance.

China's national strategy predicts that the number of EVs will reach 6.18 million in 2020 and exceed 50 million by 2030. The number of public charging stations is expected to reach 48,000, with the number of charging piles increasing from 1.22 million to 3 million and the EV to charging pile ratio moving from 3:1 to 1:1.

Cloud technology will assist such rapid growth, enabling the unified deployment and remote management of millions of EVs and charging piles. AI-powered data analytics will improve charging efficiency and battery lifespan management. And the wide coverage of 5G high-speed networks will drive the transformation of the automobile industry.

5G Slicing Solution Enables E2E Communication for Smart Grids

Load and power volume are the two key indicators of power consumption. At 11:13 a.m. on June 22, the dispatching load of CSG reached a record high of 187.8 million kW, an increase of 1.1 million kW from the previous year.

CSG has a power supply area of over 1 million square kilometers, serving over 254 million. To build a visible, measurable, and controllable power distribution network with dynamic device status monitoring and detection, along with transparent operations, inspection, and control, CSG needs to know precisely where power outages, loads, low-voltage points, and risks occur.

In order to build such a network, CSG began studying how 5G could be applied in key grid service scenarios back in 2018.

In February 2018, CSG joined 3GPP — the 3rd Generation Partnership Project, a global partnership of standards organizations that develop mobile telecoms protocols — and worked with Huawei and China Mobile to explore 5G applications for grid control services. CSG has also participated in the formulation of international 5G standards for smart grids, released a 5G smart grid white paper, tested grid control services on 5G networks, verified 5G network slicing functions, and conducted research on the 5G slice management platform.

Yang Junquan, Deputy General Manager of CSG Power Dispatch and Control Center, shared their research on the automation of smart distributed power distribution networks. A critical component of this network is the Distribution Terminal Unit (DTU), which uploads information about remote communication, measurement, and control to the distribution station for centralized control, enabling quick fault location, query, and isolation, as well as power supply switching. In the future, the smart distributed feeder automation mode — featuring integrated terminals for protection, measurement, and control — will be used. The smart mode combines circuit breakers and load switches as well as local protection and centralized control.

In order to use this mode though, CSG had to raise their communication requirements: transmission bandwidth needed to be increased to 2.5 Mbit/s or higher and reliability needed to be at least 99.999%. For high-precision time synchronization, CSG sampled voltage, current phase, and amplitude all at the same time, requiring timing precision error over the air interface to be less than 10 μs. In addition, transmission latency needed to be less than 10 ms between communication terminals and less than 15 ms between DTUs.

In a field test, End to End (E2E) latency ranged from a minimum of 6.8 ms to a maximum of 12.75 ms — averaging 8.3 ms — meeting the under 15 ms requirement. Terminal data rates reached 2.724 Mbit/s, satisfying the transmission bandwidth requirement. Finally, the timing precision of the 5G air interface was under 200 ns, meeting the requirement of less than 10 μs.

In substations, visible light or infrared cameras collected device images and real-time temperature data, and accurately matched images and identified patterns to detect device status and thermal defects. Smart substation inspection using AI cameras further improves efficiency. Robots and drones read meters and identify switch status, pressure plate status, and appearance, all based on edge computing and image recognition technologies, achieving unmanned inspection. Equipped with 5G CPE, these robots are used by CSG to replace manual on-site inspection. The system processes video images using video AI algorithms and makes automatic judgments to support smart data analysis.

CSG reached a milestone in 2020 when it completed the industry's first 5G Standalone (SA) E2E slicing function test. When two hard slices carry power and public network services, slice services are independent of each other, and Quality of Service (QoS) can be guaranteed. When a single hard slice carries two types of power services, the services are mapped to different Virtual Path Network (VPN) soft pipes to implement differentiated QoS assurance. In terms of service operations and monitoring verification, CSG verified the basic management functions of the core network and transport network slices.

Looking to the future, a single power grid is forecasted to have more than ten million terminal cards. At present, however, power supply companies need to go through the cumbersome process of applying for each card from a carrier and wait at least one week to obtain it. To address this issue, CSG, Huawei, and China Mobile conducted a test in Shenzhen that streamlined the industry's first E2E 5G SA slicing process to support service operations before, during, and after sales. Network slicing has shifted from being a purely technical implementation to a service implementation, as a result. Today, self-service purchasing, one-click order placement, and service provisioning can be completed within minutes, improving efficiency immensely.

Overall, CSG has summarized 53 typical service scenarios so far, covering power generation, transmission, distribution, transformation, consumption, and integrated services, after collecting information and communicating with business departments from the early stages of 5G. And the technical team of CSG remains committed to conducting further in-depth research, to deliver even more 5G applications in the future.

Empowering Intelligent Evolution

In the era of smart grids, ICT is deeply integrated into grid systems in terms of renewable energy access to grids, flexible interconnection of large grids, interactive supply and demand, as well as the close coupling and interaction of IT and power systems.

Industry experts point out that technologies such as Power Line Communication (PLC) and 5G will realize comprehensive perception for IoT.

Wired and wireless hybrid communication will facilitate full system connectivity, while cloud and AI will unleash data value, support flexible two-way energy flow, and lay a solid foundation for comprehensive intelligence.

Since 2018, Huawei has actively worked with China's major electric power companies and carriers on production, education, Research and Development (R&D), and the application of technology to smart grids. Working together, they have reached major milestones in the development of 5G + smart grid and continuously promoted the convergence of the two super infrastructures.

Looking into the future, all stakeholders in the power industry ecosystem need to embrace change, review strategic opportunities, and formulate coopetition strategies to promote product and service innovation. New ICT has become an indispensable part of industries' digital transformation as well as consumers' daily digital lives.