Smart grid: China says active distribution better than central transmission


Smart Grids A RD Opportunity For ChinaChinese smart grid research has concluded that the integration of renewable energy is preferable to centralizing long-distance power transmission, reports Asian Scientist.

A team led by Professor Yu Yixin of Tianjin University investigated the operation of medium-voltage distribution grids and the integration of distributed generation of renewable resources in mainland China.

The study, which was originally published in Science China Technological Sciences, outlined the contours of power distribution grids in terms of the practical distribution asset utilization, load compositions and characteristics, along with urban reliability and the integration of distributed generations of renewable resources, Asian Scientist reports.

Distribution grids to meet demand

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

The study noted 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.

Among 40 Chinese cities studied, the annual average utilization rates of major 10kV equipment were below 40% far below the comparable levels in developed countries.

Integrating renewable energy generations into the distribution grids of load centers under an ‘active distribution network’ mode is a better alternative to the centralized long-distance power transmission mode in the form of ‘wind power and thermal power bundling’ for large-scale wind power in terms of minimizing the full social costs.

Power grid weaknesses

The paper also comments that the smart grid must be based on the existing power system.

It also needs a profound understanding of existing weaknesses of current power grids and by fully tapping their potential can the system realize maximum benefits with minimum costs but admits that research on this important point is limited at present.

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.