Research On The Reliability Evaluation Of Smart Distribution Grid

Smart distribution grid is the trend of distribution system, which the greatest feature is self-healing, achieving reliable, safe, economical and efficient power supply to meet with people’s increasing demand for high reliability of power supply. As is an important part of smart distribution grid, distribution automation(DA) could greatly help network realize self-healing and improve reliability. At present, the research and application of smart distribution grid is still in initial stage, it has not been widely applied in actual system. At the same time, due to limitation of objective conditions, smart distribution grid cannot be one-off, so planning for smart distribution grid of high reliability, not only need accurate reliability evaluation, but also should have effective planning tools.According to the fact that analytical methods can get deterministic results, this thesis first divides distribution network into separate regions and establishes its simplified model based on traditional minimum cut set method. Then studies different levels of typical DA schemes for fault handling and their influence on reliability, as well as taking into account issues such as switching of isolation and contact switches, and carrying on fine analysis of power supply recovery time, smart distribution grid reliability evaluation algorithm eventually is established.In order to form a complete scheme of smart distribution grid planning, both reliability and economy need to be considered. With the help of reliability index calculated by the algorithm thesis proposed, next step the thesis using distribution network planning method with reliability and economics considered in a unified view, getting the input-output of each scheme with annual minimum income analysis method, assess economic and technical problems of distribution automation schemes in smart distribution grid, and ultimately get a reasonable distribution automation planning program. At last the thesis realizes the power system smart distribution grid reliability evaluation algorithm on the power grid planning and designing software based on AutoCAD, and uses this software to build an urban smart distribution grid case, combined with the reliability results calculated by thesis algorithm, finally get out preferred boundary conditions of system planning and construction program.