Research On Operation Control Of DC Micro-Grid Composed Of Multi Micro-Sources

With the rapid growth of the global economy,the daily life of the society and the growing demand for energy is increasing,and conventional energy sources such as oil,natural gas,coal etc.are facing the danger of exhaustion.Therefore,inexhaustible solar energy has become one of the increasing emphasis on national energy development energy.Solar energy in the form of distributed power to join the large power grid.However,the solar power generation is affected by the environment,and has the characteristics of intermittence and randomness.In order to solve the above problems,the distributed generation of photovoltaic power generation and the load of micro grid,centralized management.At present,the research of microgrid mainly focuses on AC microgrid.However,with the emergence of a large number of DC micro sources,as well as the improvement of DC power demand,the DC micro grid has gradually attracted people's attention.The paper's main work is as follow:Firstly,in this paper,the working principle,mathematical modeling and Simulation of the micro source and the corresponding converter are studied.The basic characteristics and working principle of the battery are analyzed,and the mathematical model and Simulation of the battery are presented.Secondly,we study the power electronic converter,namely the bi-directional DC/DC converter.Thirdly,the parallel operation control of the micro source is studied.The control mode of DC microgrid is introduced.A multple master-slave control strategy for DC microgrid is proposed.The control methods of constant current control,constant pressure control and droop control are analyzed in detail.Finally,In the MAYLAB/Simulink simulation environment,the effectiveness of the control strategy of the microgrid is verified.On the basis of simulation modeling,the experimental platform of low voltage DC micro grid system is built.