County Network Planning, Research And Practice

County seat is the basic unit of our country's administrative area since Chunqiu and Warring States Period. There are at all 2861 courty seats in our country at present. Their area, population and GDP are respectively above 94%, 73% and 52% of total nation's. These years, the work of "three Nong" (that is farmers, countryside, agriculture) is attached graet importance by the nation, and thus the economy of country seat develops rapidly, the demand of electric energy is becoming more and more, and substantive capital is required to strengthen the construction of electric power network every year. So the county power network planning is vital to ensure the sequenced development of the county power network and meet the county economy.There are already much reseach works on power system planning and great application achievements are obtained. Now in county power network researching field, it is a key subject to make theoretic reseach achievements more implementable by multi-angle and full-orienation studies on county power network planning utilizing advanced scientific methods and former research acheivements.In county power network planning, the problems of load forecasting, pubstation location and transmission network planning are the most important and difficult. Load forecasting is foundation of county power network planning, and exact load forecasting is propitious to decide reasonable transmission and distribution network construction plan so as to improve the stability of power network safe operation, guarantee the electric power demand and better the reliability of power supply. Substation is the junction of county power network, so if the location of substations can be programmed scientificly and reasonable locations are choosed on the base of reasonable number and capacity of planning substations, it can has a great influence on the rationality of whole network construction and the reliability, security and economic efficiency of its operation. Transmission network is the bridge of county power network. The goal of transmission network expanding and optimizing is to seek the optimal power network investment decision, which is to fix the optimal power network struction according to the result of load forcasting and substation planning project, so as to guarantee the whole power system safe, reliable and stable development for long term.The main work of this paper is discussing how to make load forcasting exact and solving optimization planning of substation locating and the problem of optimizing transmission network structure imploying the examle of Linan county power network planning. From the viewpoint of reliability and economic efficiency, how to plan a reasonable power network construction, which not only can adapt the request of county economy development and the reliablity and security of power network, but also the investment fund of county power network construction must be minimized, is also studied in this paper.