Study On Modeling Microgrid And Application On AT Station Of High-speed Railway

With the development of the world economy and the improvement of human life,the pursuit of low carbon,environmental protection,sustainable development has become the preferred way of life,which promote the rapid development of distributed generation to consumption of clean resources as the main forms of energy in recent years.But the large-scale integration of distributed power grid,the grid will cause immeasurable impact.In order to coordinate the contradiction between the distributed generation and the large power grid,the microgrid technology arises at the historic moment.Based on the outstanding advantages of microgrid,the paper puts forward a multi-guarantee power supply scheme to AT station of high-speed railway.When an emergency occurs,the original power supply circuit can't work normally,the multi-guarantee power supply system can ensure uninterrupted power supply to the equipment,and protect the equipment and personnel safety.First of all,this paper analyzes the feasibility of the microgrid to the power supply of high speed railway equipment,then puts forward two kinds of design scheme based on microgrid technology,and compares the advantages and disadvantages of the two schemes;Secondly,islanding detection is carried out by using the islanding detection method.Two the microgrid control strategy involved in the scheme is analyzed in detail in the following chapters.In the modeling of distributed power supply,the model of photovoltaic cells is simulated,and the output characteristics of PV cells are compared under different conditions.Then,by establishing the Matlab model,the advantages and disadvantages of the perturbation observation method and conductance increment method are compared and analyzed;Finally,the micro-turbine components are analyzed in detail.In this paper,three kinds of micro source control strategy Droop control,PQ control and v/f control are studied.Firstly,the Droop controller is designed and the double loop controller is designed.According to the shortcomings of Droop control,proposed an improved Droop control method with power recovery process;secondly,the design of the PQ control and PQ control of phase-locked loop,current loop parameters were calculated;furthermore,a brief analysis of the principle and the working process of v/f;finally,using MATLAB software,the improvement of three control strategy and simulation analysis of control strategy,output characteristics,and compare the Droop control before and after the improvement of the output frequency,to verify the correctness of the designed control improvements.The overall control strategy of microgrid is analyzed in detail in this paper.The establishment of the simulation model and analysis of peer control microgrid from grid connected / state switch and cut off network load increasing,the three aspects of resection of micro power output characteristics;then establish the master-slave control of micro grid model,and analyzed the simulation results by cutting load in island mode.