Research On Optimal Sizing And Energy Management For Microgrid Based On Solar/Storage

With the development of society,the world must face this difficult problem to solve the energy problem.Therefore,solving energy problems is imminent.Microgrid(MG),as a supplement to large power grids and a reasonable call for distributed energy,has received a lot of attention.With the study of MG,the reliability and economical aspects of MG operations need to be further deepened and strengthened.Optimal sizing for MG is prerequisite,and optimal energy management for MG is an important guarantee to ensure economic and reliable operation of MG.This article focuses on these two issues and the main research content is as follows:(1)Consider the cost of the battery due to the impairment of life lost resulting,based on Symons hypothesis,quantify the cost of battery breakage.Aiming at independent power supply photovoltaic/storage MG,according to the reliability and economy of MG,a bi-objective optimization configuration model of battery capacity considering the weighted duty cycle of reliability and economy is established,and an improved genetic algorithm based solving method is proposed.Case study optimal sizing in different weighted duty cycles,it is verified that the greater the duty cycle,the greater the optimal sizing.(2)Based on power supply photovoltaic/storage MG,a multi-time scale coordinated optimal energy management for grid-connected MG is proposed,including day-head scheduling and real-time dispatch.In the day-head scheduling,optimal charge and discharge of the energy storage in each time interval of whole day are arranged through the day-head scheduling.In the real-time dispatch,a day is divided into peak time,normal time and valley time.The result of day-head scheduling is adopted,different dispatching strategies are used according to current time and the state of charge(SOC)of battery storage.Case study results indicate the proposed method can not only ensure the island MG reliable and economical operation but also extend energy storage life,and help outer grid with "Peak clipping and valley filling".(3)Based on power supply photovoltaic/storage/diesel MG,a multi-time scale coordinated optimal energy management for standalone MG is proposed,including day-head scheduling and real-time dispatch.In the day-head scheduling,optimal on/off states of the diesel in each time interval of whole day are arranged through the day-head scheduling.In the real-time dispatch,SOC of battery storage is divided into five operating levels.The result of day-head scheduling is adopted,different dispatching strategies are used according to current SOC of battery storage.Case study results indicate the proposed method can not only ensure the island MG reliable and economical operation,but also extend energy storage life,and reduce frequent charging and discharging of energy storage.