Distribution automation is a set of computer technology, data transmission, control technology, modern equipment and management in one of the integrated information management system, its purpose is to improve the reliability of power supply, improve power quality, to provide users with quality services, reduce operating costs, reduce the labor intensity of operators. As the last link of transmission and distribution system, the degree of automation of distribution network is closely related to the quality and reliability of power supply. In the industrial developed countries, distribution system automation has been widely valued, with the acceleration of China's construction of smart grid process, as an important basis for smart grid distribution network automation construction has also been put on the agenda. It is predicted that in the investment composition of smart grid, distribution automation will account for about 40%, 2014-2016 will be the "blowout period" of industry demand, and the total investment scale will exceed 150 billion yuan by 2020.

At the executive meeting of the State Council held in July this year, the state identified "strengthening the construction of urban distribution networks and promoting the intelligentization of power grids" as one of the six key tasks of urban infrastructure construction; the State Grid has also established a special working group for this purpose. The promotion of the construction and application of power distribution automation has been taken as a "top priority", sounding the clarion call for the comprehensive promotion of power distribution automation, it also marks that the construction of distribution network and distribution automation, which is the weakest link in power grid construction, is about to enter a high-speed development channel.

The construction of distribution automation is listed as a "top priority", which is based on the consideration of the country to meet the needs of the construction of smart grid and the development of urbanization, and is also the internal demand of the development of distribution network. Compared with developed countries, China's distribution automation construction started late, is still in the primary stage, the market is not mature, there are still some problems to be solved.

The main problems of distribution network in China

The development of (I) distribution network is still lagging behind and unbalanced. In recent years, the investment in distribution network has been increasing, but due to the large amount of historical debts, the development of distribution network, especially the medium voltage distribution network, is still lagging behind, and the unbalanced development of urban and rural, eastern and central and western power grids is still prominent. There is still a big gap between the reliability of power supply and the international advanced level. Taking Shanghai as an example, the average annual power outage time of users is more than 5 times longer than that of Tokyo. On the whole, the development lags behind (with the needs of economic development, with foreign advanced power grids), and the region is unbalanced (urban-agricultural imbalance, east, middle and west imbalance).

The (II) power grid structure is weak and the automation level is low. The 10 kV grid structure is still weak. The gap between the city network and the agricultural network is significant. Nearly half of the 10 kV lines are still not interconnected, and the proportion of rural grid interconnection is only 1/3 of the urban network. Distribution automation level is low. Distribution automation is in its infancy, fault diagnosis, isolation and recovery time is long, and network reconfiguration and self-healing cannot be achieved. Reflected in the mutual supply capacity is poor, intuitive feeling for the restoration of power supply time is long.

The basic data of (III) distribution network is poor, and the information means are backward. Distribution network management involves different departments such as development, agricultural power, transportation inspection, marketing, scheduling, etc., and the basic data are scattered in different systems. The data standards and models between systems are inconsistent, in addition, the lack of data sharing mechanism. The low investment and low construction level of distribution network lead to the relatively lagging development of distribution network communication and information system and the lack of information access channels. Reflected in the poor degree of management refinement, data, graphics and information can not correspond, and even there is a sense of "blind".

Power Grid Development Calls for Distribution Automation

At present, there is a big gap between the power supply reliability of distribution network in China and the advanced level in developed areas, among which the lag in the development of distribution automation is the main reason. By the end of 2012, the distribution automation coverage rate of State Grid Corporation was only 10%, covering 26 provincial companies and 22000 10kV lines; while the distribution automation coverage rates of France and Japan reached 90% and 100 respectively. The investment in power transmission and distribution in the United States, Britain, Japan and other countries is about 1.2 times that of power supply investment, and the investment in distribution network is more than 1 times that of transmission network investment, while that in China is less than half of that of transmission network. Therefore, under the condition that most of the power supply and transmission line skeleton are basically completed, the focus of China's power investment needs to gradually shift to the intelligent power grid and the construction of distribution network.

At the same time, with the new power supply and load directly connected to the distribution network, it has brought new technical problems and challenges to the safe and stable operation of the distribution network; in terms of power supply reliability, China's distribution network system also has a long way to go. The solution of these problems depends on the high level of distribution automation system.

Market Opportunities and Challenges

The acceleration of urbanization has brought greater opportunities and challenges to the development of distribution network. On the one hand, the state regards urbanization as the greatest potential to expand domestic demand and increases investment in the field of infrastructure, while the distribution network is an important infrastructure for urban construction and will usher in new development opportunities. On the other hand, the development of distribution network is also facing the test of accelerating the process of urbanization.

In addition, with the rapid development of distributed power supply, a large number of electric vehicles, energy storage devices and other access, the distribution network from passive network to active network, the trend from one-way to multi-directional, and requires the distribution network to improve the adaptability, so it is increasingly urgent to speed up the upgrading and transformation.