Study On Reclosing Technology Application Of The Distribution Line Of The Small Hydropower Basin Group

As a kind of clean energy,the rational development and utilization of small hydropower station not only alleviates the resource shortage,but also reduces the pollution to the environment by coal power generation,and conforms to the concept of sustainable development.With the development of the using of small hydropower,the regional electricity grid gradually transforms the strict allocation and transmission electricity grid into the small hydropower group regional electricity grid,which is mainly based on its power of the summer output.The small hydropower distribution in this type of electricity grid is featured by the cluster and watershed.Its access line is limited due to its operating and managing characteristics and technical conditions.When the system gets into trouble,the reclosing success rate becomes low.It will influence the reliability of electricity grid operation.So the thesis carries out the research work mainly from the following parts:Firstly,from the characteristics of the distribution electricity grid of small hydropower basin group,demands analysis of its protection and reclosing function has been done.Based on the operational characteristics of small hydropower about Maoming City,the simulated analysis has been made for its connecting to distribution network relaying.We study the reclosing technology of distribution lines in small hydropower basin group and carry out a improved scheme of reclosing combining with cases,which increases success rate of reclosing series of condition after small hydropower connects system.Secondly,based on the demand of reclosing of small hydropower distribution line,a reclosing device is designed,and the hardware and software design of reclosing device is completed.The modular design of the overall design of reclosing device consists of five parts,including the main control machine,programmable logic controller,analog acquisition module,switch quantity I/O sub-module and protection function relay set.What's more,in the selected regions the typical substation practices the technological transformation in order to achieve the pilot operation.Based on the engineering design basis of substation,such as substation load,distribution lines parameters,small hydropower capacity,seasonal characteristics and so on,two sets of general scheme are designed and they are compared with the specific characteristics of field substation to choose reliable implementation plan.It is designed and accessed to reclosing device.Through designing the reclosing monitoring project,it can achieve the monitoring of project interface and the parameters.In this thesis,the overall solution of the reclosing can improve the success rate of the small hydropower grid and connected grid lines and improve the safety and stable operation of the power system.In the small hydropower group access to electricity network of distribution automation area,it has a broad application prospects.At the same time,it will produce the considerable social and economic benefits.