Multi-objective Optimal Configuration Model Of Stand-alone Microgrids Considering Power Supply Reliability

In regions such as islands,polar regions,and remote rural and pastoral areas,standalone microgrids can be an effective method to provide sufficient and reliable power supply.As these remote regions are difficult to interconnect with the main power grid,multiple objectives such as economy,environmental conservation,and power supply reliability must be taken into account for the optimal configuration.In particular,the power supply reliability of a stand-alone microgrid can be affected by various factors such as the uncertainty of renewable energy and the failure outage rate of equipment,resulting in a complex reliability evaluation problem involving sampling and failure analysis techniques.The computational scale can become extremely large when the reliability evaluation is nested in an optimal configuration model,leading to computational inefficiencies.Therefore,it is of significant practical relevance to study the high-efficient solution of the optimal configuration model for stand-alone microgrids considering the power supply reliability.In this thesis,the research is carried out on multi-objective optimal configuration problems considering the economy,environmental conservation,and power supply reliability based on typical stand-alone microgrids,focusing on the high-efficient solution of the optimal configuration scheme considering the power supply reliability.The main work of the thesis is as follows:(1)The power supply characteristics of a typical stand-alone microgrid are analyzed.The uncontrollable and controllable distributed generation,and battery energy storage system within the stand-alone microgrid are modelled.In addition,the probability distribution models describing the uncertainty of wind speed,solar irradiation,and electrical load are presented,and a hierarchical load model is built.(2)The expected energy not supplied(EENS)is adopted as the power supply reliability index of stand-alone microgrids.A quantitative evaluation method for the power supply reliability is proposed based on the "normal-failure" two-state model and correlation sampling,which takes into account the impact of equipment failure and source-load uncertainty.(3)A multi-objective bi-level optimal configuration model for stand-alone microgrids considering the power supply reliability is proposed.The model is decoupled into a master problem of equipment optimal configuration and a sub-problem of power supply reliability check based on Benders decomposition.Through the iterative solution of the master problem and sub-problem,the complexity of the optimal configuration model is significantly reduced and the solution efficiency is improved while ensuring the rationality of the configuration scheme.(4)The validity of the proposed model and the improvement of the model computational efficiency are systematically verified by case studies.The impact of power supply reliability requirement and energy storage system on the configuration scheme of the stand-alone microgrid is analyzed,as well as the algorithm convergence.