Research On Static Voltage Stability And Optimal Allocation Of Distributed Generation Access To Distribution Network

It is the inevitable trend of future power grid development that the large scale renewable distributed power generation will be integrated into large power network in the form of micro-grid,running in parallel with large power network,forming intelligent distribution network which enables two-way interaction of energy and information between distributed power generation and system departments.Under this background,renewable and distributed clean energy has become the fortune's favourite under the development of electric energy with its unique advantages of cleanness,environmental protection,high efficiency,energy conservation and safety.But the way distributed power works in parallel with the power grid,so a lot of distributed power devices are integrated into the distribution network.Although it can effectively reduce the burden of power supply,environmental pollution and energy consumption,it also complicates the network structure of distribution network,which has many negative effects on the management,planning and safe and stable operation of distribution network.Therefore,it is very important to plan distribution network with distributed power.First of all,this thesis makes a detailed study of the generation mechanism and technical characteristics of several typical distributed generation technologies.On the basis of this theoretical research,the influence on the voltage distribution and the system voltage stability of feed line nodes is analyzed from three aspects: access location,access capacity and power factor change of distributed power supply into distribution network,and obtains the conclusion by simulation analysis.Secondly,a multi-objective optimal configuration model with the objective of least network loss and maximum static voltage stability margin is established for the planning problem of distributed power supply.In the process of model solving,the problem of multi-objective function optimization is transformed into the problem of integrated objective function optimization based on the weight coefficient method,so that the relations between the various sub-goals are reasonably coordinated,and the whole optimization of the objective functions is realized.Then,by comparing the differences among the various algorithms,a multi-agent swarm(MAPSO)algorithm,which combines the advantages of multiple agent(MAS)and standard particle swarm(PSO)algorithms,is studied.This algorithm not only gives full play to the competitive cooperation and independent learning advantages among agents in MAS,but also draws on the advantages of the evolutionary mechanism of PSO algorithm that it can share knowledge with the global optimal Agent and modify the action strategy of each Agent based on its own experience,so that the algorithm can quickly and accurately converge to the global optimal solution.Finally,the fast convergence and high precision of the MAPSO algorithm are verified by comparing the algorithm with the PSO algorithm.Furthermore,MAPSO algorithm is used to solve the multi-objective optimization configuration model to obtain the optimal configuration result of DG in the distribution system and verify the effect of DG optimization through simulation analysis.