Benefit Assessment And Operation Strategy Of The Distributed Pumped Storage Systems

With the improvement of people's living standard and the adjustment of industrial structure, the structure of the power load in the power system is constantly changing. This situation causes that the difference between peak-time and valley-time of the power load has been increasing year by year, which is a critical problem that the power system is facing. At the same time, the proportion of the intermittent power sources in the power system, such as wind power and photovoltaic power, is gradually increasing. This situation has a serious influence on the safe and stable operation of the power grid. One of the effective means to solve these problems is expanding the scope of the application of the energy storage technology in the power system.Pumped storage is a mature energy storage technology, and it has many significant benefits in various aspects. Current researches on pumped storage system mostly focus on the operation mode and benefit assessment of the large pumped storage power plant. However, due to the geographical limitations, some areas are not suitable for the construction of the large pumped storage power plant. Meanwhile, there are many small hydropower stations, electric pumping stations and small pumped storage power stations in rural and mountain areas. The utilization ratio of the small hydropower stations and the electric pumping stations is perhaps very low, and the economic benefit may be also small. If the existing equipment can be used to construct a system which has the function of pumped storage, then the related problems in the power system can be solved, and the economic benefit of the small hydropower stations and the electric pumping stations can be also improved.Based on the thoughts above, this paper makes use of existing facilities to construct the distributed pumped storage system. The distributed pumped storage system is made up of some associations that are independent each other. The whole system is a decentralized and autonomous system. Each association has full autonomy. The participants can flexibly construct associations according to their actual situation, which shows the principle of adjusting measures to local conditions. This paper mainly introduces construction modes of three kinds of typical associations, which can be utilized to construct other types of associations.Referring to the method of benefit assessment of the large pumped storage power plant, this paper assesses various benefits of the distributed pumped storage system, and analyses its benefits to the participants, power grid corporation, power sources in the power system and the whole society. Aiming at the autonomous characteristics of the distributed pumped storage system, this paper mainly assesses its static benefits, especially the economic benefits. Results show that the distributed pumped storage system has great benefits in the aspects of economy, environment and society. Based on the thought of the autonomy of associations, this paper designs operation strategies of the distributed pumped storage system, which is actually designing different operation modes of different associations. This paper mainly designs the operation modes of three kinds of typical associations. Besides, this paper establishes runtime economic models of the associations, and designs the benefit distribution mechanism among participants in the association. Results show that the operation modes in this paper are easy to implement, and can get great economic benefits.This work was conducted as a part of the Project 50877014 supported by Natural Science Foundation of China and the Project 20102302110021 supported by Specialized Research Fund for the Doctoral Program of Higher Education.