Research On The Impact And Risk Assessment Of Distributed Power Grid Integration On Power Grid

The distribution network is the last link from the power grid to the users.Its safety directly affects the safety of the users’ electricity.With the integration of a large number of distributed power sources,while meeting the load demand,it also brings the many problems.In order to ensure the stable operation of the power grid,it is necessary to plan the grid connection of distributed power sou rces reasonably,and the risks brought by grid connection of distributed power sources will be minimized.First,the composition of several common distributed power sources and their working principles were studied,and the probability models of distribute d power sources and loads were established.The impact of distributed power grid connection on the power grid is studied.The location and capacity of the distributed power grid connected to the power grid will cause changes in the distribution network vol tage fluctuation and network loss.The grid-connected power supply was verified,and the technical solution to ensure the safe and stable operation of the distribution network after the distributed power supply was connected was presented.Then,the potential risk sources in the power grid are analyzed to provide a basis for the selection of risk assessment indicators.For the current methods of risk assessment,the analytical method,Monte Carlo simulation method and fuzzy analytic hierarchy process are compared.The analytical method has high accuracy,but with the complexity of the system and the increase in the number of components,its modeling is complicated and calculation large.The Monte Carlo simulation method is particularly suitable for large-scale systems.The number of samplings does not change with the change of the system scale.The calculation result is more in line with the actual project,but the calculation in the actual project is cumbersome and requires repeated iterations.The fuzzy analytic hierarchy process establishes a judgment matrix on the established risk index,uses the judgment matrix to obtain the weight index,and then evaluates the risk.The calculation is simple and convenient.However,the judgment matrix is mainly built on the advice of on-site operation and maintenance personnel and expert scoring,there are more artificial factors mixed,and the judgment results lack objective basis.Finally,based on the potential risk sources in the power grid,referring to the principle of risk assessment index selection,the utility function is used to establish the power system risk assessment index.The sampling process of Monte Carlo method is improved by using equal-distribution sampling method and expected fault set,and the sampling speed is improved.Combined with specific calculation examples,the node voltage exceeds the limit,the branch is overloaded,the main transformer load rate is not balanced The risk assessment was carried out,the advantages before and after the improvement of Monte Carlo method were compared,and the superiority and practicability of the improved algorithm were verified.