Research On Distributed Generation Planning And Optimimal Dispatch In Island Microgrid

With the improvement of the attention in the field of marine environment,the effective exploitation of island natural resources and its further rational use have all become the focuses of our country’s scholars.Compared with power grids in island area,the regional power grid on land has its own particularity and the meteorological environment is more complicated,which poses a challenge to the power reliability of the island area.At the same time,the integration of renewable energy sources,which are diverse in variety and susceptible to many factors,into the island grid will further increase their uncertainty.Scientifically allocating renewable energy capacity and developing good scheduling programs are two important ways to effectively improve the reliability of island grids.Therefore,this paper focuses on the island microgrid in an uncertain environment,from the perspective of capacity planning and optimal scheduling of renewable energy sources.The main works are summarized as follows:First of all,the typical structure of island microgrid with seawater desalination is introduced.The output of power generation system units which are directly affected by the natural time-dependent degeneration of renewable energy power sources is analyzed.The mathematical model of distributed power supply and load is establishedSecondly,aiming at the problem of capacity planning in the distributed power generation of island microgrids,the fresh water load device with good power coordination is introduced.A running strategy of assisting power balance adjustment is proposed,and the power difference is compensated by other distributed power sources.According to the annual economic cost and the renewable energy utilization rate,combined with the annual meteorological conditions and residential water consumption,the niche multi-objective particle swarm optimization is used to solve the power capacity planning problem.Thirdly,in view of the randomness of the renewable generation power and the inaccuracy of the prediction error,a scene analysis method is applied to deal with the random variable considering the error.Based on the stochastic programming theory,the island microgrid schedule is obtained.In the study,a variety of scene sets of renewable energy were obtained by using Latin hypercube sampling and scene reduction methods.Based on the reduced scene data,a multi-scenario probability prior scheduling model was established.In order to verify the impact of randomness of renewable energy on the optimal scheduling results,a numerical example is given to validate this method.At last,based on the unspecified planning theory and probability function distribution method,the optimal operation of renewable energy is analyzed.In order to ensure the universality of the model,the two operation modes of off-grid and grid-connected operation are studied respectively.Then,based on the distribution characteristics of renewable energy,he author analyzes the expectation of power shortage under different confidence levels.The chance constrained programming model of the island microgrid in the two operating modes is calculated and analyzed respectively,and the output power of island microgrid dispatchable units and the transaction with large power grids are obtained.The results of the cases also verify the feasibility of the proposed model and strategy.