Research On Optimal Configuration And Coordinated Operation Of DC Microgrid

With the rapid development of renewable energy power generation,the technology of microgrid has attracted much attention.At present,microgrid is mostly in the demonstration and experimental stage,and will play a n important role in the future power transmission and distribution field,which has good prospects for development.Compared with AC microgrid,DC microgrid has advantages of simple control and less energy consumption.This paper focuses on optimal configuration and coordinated operation of the microgrid.The optimal design of microgrid is the most important problem in the planning phase.This paper simulates the basic weather and load data by using HOMER software.In addition,in order to improve the convergence performance of the algorithm,based on the adaptive particle swarm optimization algorithm,the modified particle swarm optimization algorithm is proposed for the "mutation" process in genetic algorithm,which is convenient for the optimal allocation problem in microgrid.For the optimal sizing of DC microgrid,several evaluation indexes such as annual investment cost,power supply reliability and energy utilization rate are established.At the same time,the optimization problem is solved by MPSO algorithm.For the off-grid microgrid,the optimal sizing of multi-nodes microgrid is studied,and a single post failure reliability index is formulated to evaluate the overall performance of the system,which provides suggestions for the planned outage and power maintenance of the whole system.For the on-grid microgrid,a new configuration strategy is used to perform the energy scheduling between the large grid and the battery,which reduces the number of configuration of battery,and improve the economic performance of the whole system in the same power supply reliability.In addition,in order to meet the needs of more power users,the application software platform of optimization configuration for microgrid is developed by using GUI in MATLAB software.The platform can directly optimize the configuration of various modes of microgrid,which is easy for users to operate,and has higher reliability.Optimization of DC microgrid is aiming at power balance in normal operation of the system,in order to ensure the stability of DC microgrid system,so as to meet the requirements of dynamic operation,this paper set s up the entire microgrid system model,formulated a hierarchical/droop control strategy,and the effectiveness of the control strategies is verified by network fault and off-grid operation condition.The simulation results show that in a variety of special operating conditions,the fluctuation of the bus voltage is less than 5%,which meets the requirements of the power quality.Meanwhile,the whole system can eliminate the communication lines,which have the advantages of low investment cost,simple control structure,and the "plug and play" function of each micro source is realized.