Stability Analysis Of Distributed Power Generation System With New Energy And Energy Storage Devices

With the decreasing conventional energy reserves and the increasing environmental consciousness,the traditional form of energy supply is unable to satisfy people’s increasing needs.Therefore,distributed generation system which contains the large-scale renewable energy source(such as solar energy,wind energy)has been developed vigorously.At present,many related technologies and experimental works in the field of distribution generation systems have been developed at home and abroad,including a lot of researches and analysis on the DC microgrid with new energy and energy storage,especially on the stability of DC microgird systems with distributed power.Recently,the research on the stability of DC microgrid system with new energy and energy storage equipment has become the emphasis and difficulty of the distributed power generation system.Therefore,the paper mainly focuses on the research of the DC micro-grid with solar energy,energy storage and constant power load to analyze the stability of a typical distributed generation system.The paper is structured as below:First of all,the typical DC microgrid is used as the research object and the large signal equivalent models of the Power,Energy storage and Load in the distributed power generation system are established.Then,the small signal average model of power converter in different control mode are built by using the method of state space linearization.Secondly,the simple photovoltaic system is taken as an example to analyze the effects on the converter output impedance caused by the droop coefficient,input current,output voltage and circuit equivalent capacitance.Then the influence of these parameters on the system stability is analyzed.The small signal stability of the photovoltic system is also analyzed by using the method of impedance ratio analysis.Finally,we mainly focus on the small DC microgrid which contains photovoltaic,energy storage and load.The large signal and small signal stability of the DC microgrid are analyzed by using the Lyapunov Direct Method and new types of parallel impedance analysis method respectively.The effects of the related parameters on the system stability of large signal are also explored to provide a certain theoretical guidance for the design of system and improve the limitations of the impedance ratio analysis methods effectively.