Multi-objective Optimization Of The Configuration Of Micro Grid Composite Energy Storage Capacity

With the gradual development of the power grid and the increasing demand for electricity,the traditional mode of operation of large power grid encountered more and more problems,including energy shortage and power generation process produces a large amount of pollution and long distance distribution caused by large power loss,have prompted people to study more convenient and more secure power generation and distribution at this time,the micro grid into everyone's sight.Micro grid distributed generation technology is the basis of the existing distributed generation,power supply is relatively more flexible,can use in the load location,to generate electricity by using local solar,wind or some special energy around.This kind of power generation mode does not require long distance transportation to power,reduces the loss of electric energy and improves the utilization of energy.And many renewable sources of energy have been used to reduce the loss of fossil energy.But there are all kinds of problems in distributed power,including strong randomness,indirectness and volatility.These features will greatly reduce the stability and security of power grid operation,improve the difficulty of power system control,and increase the risk of power system operation.Therefore,in order to make full use of the advantages of distributed power supply,and to reduce the shortcomings of distributed generation to the maximum extent,the concept of microgrid is proposed.Microgrid can be integrated through the two modes of grid connected operation and island operation,which can well integrate and utilize distributed power in different regions,and reduce the volatility and randomness of renewable energy in distributed generation by incorporating energy storage system.After referring to a large number of literatures,we understand the operation and problems of microgrid,and focus on the functional structure and operation mode of microgrid.If found to solve the micro grid distributed power supply problems need the help of energy storage equipment to improve,and in the existing micro network,storage devices of various types,but there is no fixed storage theoretical support on the way,according to a study on the existing storage methods,storage battery and super capacitor apparatus there is a strong complementarity,and can improve the characteristics of the micro grid has defects,considering the battery and super capacitor hybrid energy storage mode analysis.Therefore,a multi-objective function of composite energy storage is formulated based on three indicators,which are the lowest cost,the fluctuation of renewable energy and the balance of energy supply and demand,and particle swarm algorithm is applied to solve this objective function.Finally,an example is applied to calculate the indicators under the condition of composite energy storage and single battery energy storage and without energy storage equipment to analyze and illustrate the feasibility and advantages of this multi-objective optimization.