The May/June Issue of the Electrical Insulation Magazine has been released. Use the accordion headings below to explore this issue’s content, and visit the IEEE Xplore for full magazine access.
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Insulator Surface Charge Behaviors: From Hazards to Functionality
Isolated-Phase Bus—Design, Operation, Deterioration, and Failure
James E. Timperley
Energy Harvesting: An Overview of Techniques for Use Within the Transport Industry
Chongqing University, China
New Power System Infrastructure in China
Since 1985, the year of the first issue of our magazine, the world’s population has grown from less than 5 billion to almost 8 billion people. During the same period, electricity generation grew by more than 280%. The growth is continuing. From prospections, there will be more than 8.5 billion people, with 6 billion in urban conglomerations, in 2030. World electricity generation is expected to grow by 40% from 27,000 terawatt-hour (TWh) in 2021 to 37,000 in 2030, which should play a big role in helping 70 million people globally who do not have access to electricity.
China produced more than one-fourth of the global electricity generation in 2021. More than half is sourced from coal, and more than 80% is sourced from fossil. It is encouraging that the country is to place strict controls on coal power, with limits on the expansion of coal consumption during the 14th Five Year Plan period (2021~2025) and gradual reductions in the 15th Five Year Plan period (2026~2030), which should pave a solid road to attain net-zero carbon emissions by 2060. For sure, China’s carbon neutrality commitment will speed up decarbonization in its power system. Energy storage, digitalization, and the retiring of polluting assets will all be key to this revolutionary conversion. This is the echo to the call in 2021 for building a “new power system centered by new energy,” which uses sources like hydropower, renewables, and nuclear. The new power system is based on new energy as the main supply, aiming at energy and power security and meeting the power needs of economic and social development. It is a power system with the following basic characteristics: clean and low carbon, safe and controllable, flexible and efficient, intelligent and friendly, and open and interactive.
Over the past two decades, renewable energy technologies have grown more robust and efficient and are increasingly capable of generating power even in suboptimal conditions such as low wind speeds and low solar irradiation. Energy storage technologies are improving quickly. As a result of state support in Europe and the United States and the rise of new manufacturing powerhouses such as China, costs have reduced to an economical level. This has provided significant feasibility and highly reasonable ground in constructing the new power system. The call to have “new energy at the center” steeply elevates the importance of renewable energy sources, indicating that either installed capacity or output from new energy sources should make up over half of the total by 2025.
The installed capacity of wind power and photovoltaic power generation in China has grown significantly since 2010, but the proportion of wind and solar power generation in the power system accounted for only 2.9 and 5.4% in 2019. However, under China’s “net-zero carbon emission” goal, it is predicted that by 2060, the combined proportion of wind power and photovoltaic power generation capacity needs to reach about 80%, and the sum of power generation will account for about 70%. A summary for 2016~2020 evidenced that the increase in wind power and solar power generation has reached 587.2 billion kWh, which means a huge reduction of coal consumption by 250 million tons and an equivalent 450 million tons emission reduction of CO2 .
Ultra-high-voltage direct current, a powerful alternative to alternating current, takes electricity farther with less loss, which meets the demand in China to bridge vast distances between the new energy power plants that are mainly located in western China and the eastern coastal urban centers consuming much of the country’s power. The world’s first transmission line operating at ±1,100 kV, the Changji-Guquan UHVDC transmission line crosses 3,324 km with transmitting capability of up to 12 GW electricity, and 7 UHVDC transmission lines are planned for 2021~2025. However, HVDC is unlikely to exceed HVAC because the huge stock AC system cannot “brake suddenly” and “turn sharply,” but also the proportion of installed capacity and power generation of synchronous power sources such as thermal power, hydropower, and nuclear power will occupy a considerable rate in the next several decades.
Owing to the randomness and low inertia of new energy, comprehensive changes are required in all aspects of Source–Network–Load–Storage to ensure the safety and stability of the power system. It is obvious that power storage is just beginning to grow. However, China’s power storage needs to fill a huge gap from technology to installed capacity. The energy research institute of the China State Grid, the leading power company in China, predicts that China’s new energy storage will grow rapidly after 2030, and the installed capacity will reach about 420 GW in 2060, from 2.1 GW, the value of the cumulative installed capacity of new energy storage in 2019.
Several provincial plans published in 2021 indicate that one focus will be on pumped-water hydroelectricity—a way of storing energy by using cheap electricity to pump water to a higher elevation during periods of surplus supply and release it through turbines to generate electricity when there is a peak in demand. Jiangxi is due to start work on the Fengxin Pumped-Storage Hydroelectricity Station; Shandong plans second phases of work at facilities in Yimeng, Wendeng, Weifang, and Tai’an; Shanxi is moving ahead with work in Yuanqu and Hunyuan; Chongqing is accelerating preliminary work in Liziwan; and Xinjiang is working on facilities in Fukang and Hami. By 2021 in China, the installed capacity of the pumped-water hydropower station in operation was 30 GW, and the scale under construction exceeds 50 GW.
In 2021 electrochemical energy storage is welcomed by favorable policies. The China National Energy Administration issued an announcement that clearly stated that by 2025, large-scale new energy storage development will be realized and manifested by more than 30 GW installed capacity. It has been estimated that the compound annual growth rate of new energy storage will exceed 50% from 2020 to 2025 . A scenario analysis has profiled that the cumulative scale of electrochemical energy storage in China will reach 35.5 GW in 2025, and an optimistic value of 55.9 GW is expectable.
The addition of huge quantities of variable new power sources has created a strong need for smart control systems across supply, the grid, demand, and storage. It is also becoming more necessary to build basic digital infrastructure to support this, which fits well with the “smart grid” concept. A paper in 2021 from China Southern Power Grid discussed deep integration between digital and physical networks with guiding information flows and optimizing power and services flow to support the construction of the new power system.
The transition to the new power system requires a huge investment. China State Grid has announced in September 2021 that it plans to invest 350 billion US dollars (2 trillion Chinese Yuan) in the next five years to promote the transformation and upgrading of the traditional power grid . The new power system involves almost the entire power sector: converter valves, power and distribution transformers, instrument transformers, circuit breakers, GIS and GIL, insulation devices, cables, towers, etc. There is certainly a call for new insulation technology: dielectric materials, devices, equipment, and systems. All the objects fall within the scope of dielectrics and electrical insulation, and we are proud to initiate a new column “Stories from China” in our magazine, to offer readers the progress and roadmap in China, the most critical issue being limiting warming to 1.5°C.
In guru Peter Drucker’s words: “A time of turbulence is a dangerous time, but its greatest danger is a temptation to deny reality.” For every person of insight who aspires to occupy a place in the carbon-neutral era and achieve greater development, taking the initiative to seek change is a necessary measure to answer the proposition of the times. DEIS and its members and colleagues are ready and active; we have diversity to keep power systems stable and safe via changes.
Best Regards, Feipeng Wang
 State Grid Corporation of China, “Carbon Peak, Carbon Neutral Action Plan,” Mar. 2021. Accessed: Feb. 15, 2022. [Online]. Available: https://www. in-en.com/article/html/energy-2301493.html
 National Energy Administration, “Guiding Opinions on Accelerating the Development of New Energy Storage,” Jul. 2021. Accessed: Feb. 15, 2022. [Online]. Available: https:// www.ndrc.gov.cn/xxgk/zcfb/ghxwj/ 202107/t20210723_1291321.html?code=&state=123
 Baoan Xin, “Actively building a new power system and unswervingly taking the road of green development,” presented at the International Forum for Energy Transition, Beijing, China, 2021.
From The Editor
Editor in Chief
Incidentally, I wish that the sky remains as bright as it is in the cover photo of the magazine and we are able to travel with more freedom as a number of conferences take place this summer in person. The list includes conferences such as ICDL in Sevilla, Spain; ICD in Palermo, Italy; and the co-located EIC and IPMHVC in Knoxville, TN, USA. However, it is always best to be ready for the unexpected; thus, online conference participation is also offered.
It has been a great start as an Editor in Chief of the magazine in terms of new article submissions from around the globe, with a wide variety of review and tutorial-type articles on electrical insulation phenomena and applications. This issue is launched with an editorial from Feipeng Wang, on the new power system infrastructure in China. A new column, “Stories from China,” is also introduced by Lv Zepeng, our new contributing editor. Both the editorial and the column “Stories from China” give us a taste of the changes that are taking place in generation, transmission, and distribution power networks and associated challenges and successes in electrical insulation. A report on the popular thematic school on dielectrics from last summer is also included in the bulletin board section.
This issue of the magazine starts with a tutorial article in which the authors introduce surface charging phenomena and potential applications of design optimization of electrical insulators. Then, there is an article on isolated-phase bus with degradation and failure examples from the service environment. The third article is an introduction to energy harvesting and potential application in the transport industry.
The first article in this issue, “Insulator Surface Charge Behaviors: From Hazards to Functionality,” is authored by Chuanyang Li, Jingjing Fu, Yunlong Zi, and Yang Cao from the University of Connecticut in the USA and the Chinese University of Hong Kong in China. In this article, the surface charging phenomena of insulation materials are explored by reviewing key scenarios and charge tailoring methods. The authors also introduce different applications that benefit from an understanding of insulation surface charging phenomena and provide ideas on converting hazard sur- face charge to a design function. One of the application examples is a novel DC spacer where the shape and doping ratio of semiconductive fillers is optimized to minimize the electric field distribution. The authors also describe a self-powered wireless sensing e-sticker that converts hazard charges into functional charges.
The second article, authored by James E. Timperley from J E Timperley Consulting LLC, Ohio, USA, is titled “Isolated-Phase Bus—Design, Operation, Deterioration, and Failure.” In this article, the author describes the design considerations, operation limitations, deterioration mechanisms, and failure prevention of air-insulated isolated-phase bus (IPB). The author discusses the differences between air-insulated and gas-insulated bus as well as the advantages and disadvantages of noncontinuous and continuous enclosures. Then, the article introduces the different conductor insulator arrangements, together with examples of service failures. The author describes the dominating mechanism that can degrade the IPB and highlights areas of deterioration on the enclosure. The article also introduces examples of corrosive attack on the conductor and internal surface of the enclosure due to nitric acid produced by partial discharge activity. The author then focuses on the conductor deterioration by describing various failure modes with potential route causes and monitoring techniques through which some of them can be detected.
The third article is titled “Energy Harvesting: An Overview of Techniques for Use Within the Transport Industry,” authored by Neil M. White from the University of Southampton, Southampton, UK, and Bahareh Zaghari from the Centre for Propulsion Engineering at Cranfield University, Cranfield, UK. The focus of this article is on energy harvesting techniques for generating electrical power from ambient energy such as vibration, heat, and light. The authors introduce the opportunities in sensing system applications and their associated, often wireless, communication channels. The authors also describe examples of energy harvesting mechanisms based on the different forms of energy. The article provides a broad overview of energy scavenging techniques, along with an assessment of useful materials for each mode of harvesting. The article then introduces potential applications of energy harvesting such as aircraft systems and the rail industry, and a case study is presented on a prototype electromagnetic vibration harvesting system with a tunable resonant frequency.
News from Japan
Stories from China