Research On Energy Optimization Of Multi-microgrid System

The increase of population and energy consumption intensify make us extremely urgent to develop new energy.As a supply mode of large power grid,independent source micro-grid has become a trend that the global study of it is increasingly extensive and in-depth.With the development of micro-source and smart micro-grid technology to a certain extent,there are many different types of micro-grid outside the distribution network.A multi-microgrid system can be formed by two or more micro-grids within a specific area and close to each other in distance.The diversity of a single micro-grid in the system leads to the diversity of the system,and also increases the composition difficulty coefficient of the whole system.At this point we must consider how to implement the exchange of energy and power within N sub micro-grids in the network group efficiently,so as to improve the utilization rate of micro source and achieve economic optimization become the top priority purpose of the study.This paper focuses on the hot issue of multi-micrgrids system energy optimization,and its main research contents are as follows:(1)Grasp the basic structure of micro-grid and micro-grid group system,and understand the advantages of micro-grid group over single micro-grid in depth.(2)Energy storage plays an important role in multi-microgrids system.When the micro source power is greater than the power required by the load,the energy storage can absorb the electric energy.When micro-source power cannot supply all users with electricity,energy storage can assist in power supply.In this way,the stability of power supply can be greatly improved.However,due to the high cost and maintenance cost of energy storage device,we cannot use energy storage in large quantity or without capacity limit when building multi-dimensional network system,and we should have a reasonable plan for itscapacity.In addition to certain requirements for energy storage capacity,we also need to consider the installation site for the energy storage device.(3)Before energy optimization of multi-microgrids system,the group power must be balanced.Firstly,it is necessary to understand the control methods of micro-grid and micro-grid group.In this paper,I use the hybrid coordination method for power balance.Each micro grid uses its own suitable control method to control the internal power and then gives the total control to the group.That is to say,it uses both single micro-grid control and hierarchical control.Simulation results show that the method is effective for power balance.(4)The core of this paper is the research on energy optimization of multi-microgrids system.For a micro-grid system with a high degree of freedom and complexity structure,we use an energy optimization method based on hierarchical control to solve the energy exchange among the sub-nets in the whole system.Firstly,establish the energy management model of multi-microgrid system.Secondly,add the influence of each sub micro-grid on the system,and optimize research of energy within the micro-grid group.Finally,establish a simulation to verify the effectiveness of the proposed method.