Nav: Home

Chinese power: Challenges and R&D opportunities of smart distribution grids

October 19, 2014

After conducting an investigation about the current state of the operation of medium voltage distribution grids and the integration of distributed generation (DG) of renewable resources across China, scientists at the Key Laboratory of Smart Grid, under the auspices of the Ministry of Education, at Tianjin University in the east coast city of Tianjin, set out an array of R&D opportunities to modernize these grids.

Researchers Yu Yixin, Zeng Yuan, Liu Hong and Sun Bing state in a recent paper published on the Beijing-based journal SCIENCE CHINA Technological Sciences that it is urgent to modernize China's distribution grids, and that R&D opportunities aimed at reaching that goal should be mapped out and seized.

In their study, "Challenges and R&D opportunities of smart distribution grids in China", these researchers outline the contours of power distribution grids in terms of the practical distribution asset utilization, the simultaneity factor of feeder loading, load compositions and characteristics, along with urban reliability and the integration of distributed generations of renewable resources.

These scientists write in the new study that "the challenges to modernize the distribution grids in China are to improve the asset utilization rates, the electricity efficiencies and the reliability of distribution systems, as well as to integrate increasing amount of variable distributed renewable resources".

Smart grid is an evolving goal as a key development strategy across China, they explain. And constant research is needed to forecast fluctuating demand and to estimate changing costs and benefits.

But the smart grid can only be constructed based on the existing power system, they point out. Only through a very profound understanding of existing weaknesses of current power grids and by fully tapping their potential can the system realize maximum benefits with minimum costs. Yet research on this important point is limited at present, although scholars in China have done lots of research about smart grid and power companies have invested extensive amounts of funds and manpower on related pilot projects.

For the sustainable development of society, improving the power asset utilization rate has always been regarded as a mission with high priority in power companies of developed countries, they explained

According to statistics, the researchers noted that distribution assets involving the investment up to trillions of Chinese yuan accounted for more than half of the entire grid of China.

Among 40 Chinese cities studied, they explain, the annual average utilization rates of major 10kV equipment were below 40%, far below the comparable levels in developed countries (please see Figure 1).

The customer average interruption duration index (CAIDI) of urban 10kV users in China was 7.01 hours in 2011; during the same period this index averaged 74 minutes for urban and rural users in the U.S. The index ranged from 40 to 70 minutes in developed European countries and was less than 5 minutes in Japan and Singapore.

Yu Yixin, co-author of the paper, states that major equipment deployed across distribution grids in most Chinese cities is running with low loads, and that 10kV distribution grids are operated with a relatively large margin. But large margins ordinarily coexist with high reliability, not a low one. This is a question which needs careful consideration.

The cost of distributed generation of solar and wind power is reducing to an economically viable level, and the payback period is around 7 to 10 years. Integrating renewable energy generations into the distribution grids of load centers under an "active distribution network" mode (mode II in figure 2) is a better alternative to the centralized long-distance power transmission mode in the form of "wind power and thermal power bundling" (mode I in figure 2) for large-scale wind power in terms of minimizing the full social costs.

The U.S., some European countries and Japan have accumulated extensive experience and developed standards and protocols. However, comparable work is just beginning in China.

Professor Yu Yixin states that the current distribution grids in China should improve the economic efficiency of construction and operation urgently, especially the asset utilization rates.

Under the current system, Professor Yu explains that the reliability of power supply and the power quality cannot meet the requirement of the upcoming digital society.

At the same time there is a checkerboard of challenges to be crossed in integrating distributed generation, including renewable energy, Professor Yu adds.

Based on the above challenges, an array of R&D opportunities is listed in realizing smart distribution grids by the authors of this paper.

Efforts to seize these R&D opportunities should be aimed at the models and topologies of network infrastructure, at the communication and interconnection methods and related technologies, and at the function of self-healing and operation optimization and voltage management.

Likewise, R&D should be targeted at utilizing demand response and demand load control and improving electrical efficiency, at related laws and regulations on the power market, and at fostering smart grid investment and informing regulatory frameworks.

Meanwhile, attention associated with R&D opportunities should also be paid on flexible plug and play on EV, on standards and protocols for communication and interoperability of smart distribution grid considering DG, on comprehensive models and tools for robust operations and planning.
-end-
This research received support from the National Social Science Foundation of China (Grant No. 12&ZD208).

See the article:

Yu Y, Zeng Y, Liu H, Sun B. Challenges and R&D opportunities of smart distribution grids in China. SCIENCE CHINA Technological Science, 2014, 57(8): 1588-1593.

http://link.springer.com/article/10.1007/s11431-014-5585-2?sa_campaign=email/event/articleAuthor/onlineFirst

SCIENCE CHINA Technological Science is produced by Science China Press, a leading publisher of scientific journals in China that operates under the auspices of the Chinese Academy of Sciences. Science China Press presents to the world leading-edge advances made by Chinese scientists across a spectrum of fields.

http://www.scichina.com/english/

Science China Press

Related Wind Power Articles:

Energy-efficient power electronics -- Gallium oxide power transistors with record values
The Ferdinand-Braun-Institut (FBH) has now achieved a breakthrough with transistors based on gallium oxide (beta-Ga2O3).
The complicated future of offshore wind power in the US
In recent years the US Department of Energy laid out an ambitious plan to grow the US offshore wind sector.
Wind power vulnerable to climate change in India
The warming of the Indian Ocean, caused by global climate change, may be causing a slow decline in wind power potential in India, according to a new study from the Harvard John A.
Solar power -- largest study to date discovers 25 percent power loss across UK
Regional 'hot spots' account for the power slump and these are more prevalent in the North of England than in the south
Large-scale US wind power would cause warming that would take roughly a century to offset
Extracting energy from the wind causes climatic impacts that are small compared to current projections of 21st century warming, but large compared to the effect of reducing US electricity emissions to zero with solar.
Large-scale wind power needs more land, causes more climatic impact than previously thought
In two papers, Harvard University researchers find that the transition to wind or solar power in the United States would require five to 20 times more land area than previously thought, and if such large-scale wind farms were built, would warm average surface temperatures over the continental United States by 0.24 degrees Celsius.
Report confirms wind technology advancements continue to drive down wind energy prices
Wind energy pricing remains attractive, according to an annual report released by the U.S.
Evaluation method for the impact of wind power fluctuation on power system quality
Abrupt changes of wind power generation output are a source of severe damage to power systems.
Nuclear power shutdowns won't spike power prices
Despite economic woes that could shutter two of Pennsylvania's nuclear power plants -- which generate 6 percent of the state's power -- power prices will remain steady due to low natural gas prices, according to Seth Blumsack, associate professor of energy policy and economics, Penn State.
The true power of the solar wind
The planets and moons of our solar system are continuously being bombarded by particles from the sun.
More Wind Power News and Wind Power Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.