Multi-Time-Scale Energy Management Strategies For Photovoltaic-Storage Microgrids

As the main technical means to efficiently utilize distributed photovoltaic power generation and smooth the fluctuation of new energy output power,the solar-storage microgrid has developed rapidly in recent years.The research object of this paper is the optical storage microgrid,and studies the simulation modeling method,multi-time-scale energy management strategy and energy management platform designing of the photovoltaic-storage microgrid.First,a simulation model of the photovoltaic-storage microgrid is established.Based on the structure,operation principle and control method of the photovoltaic-storage microgrid,and in accordance with the generalized and modular design idea,the simulation models of photovoltaic power generation system,energy storage system and photovoltaic-storage microgrid are built in the Matlab/Simulink environment,the simulation of various control strategies of the photovoltaic-storage microgrid in grid-connected and off-grid operation modes is realized,and verified its correctness.Then,a multi-time-scale energy management strategy for solar-storage microgrids in grid-connected operation mode is proposed.The strategy includes two stages: day-ahead optimization scheduling and intra-day rolling optimization.In the optim ization scheduling stage,the centralized control and distributed control are comprehensively utilized,and all the distributed photovoltaic storage units in the microgrid are equivalent to a cluster,according to the short-term forecast data of photovolta ic output and load demand.Combined with the time-of-use electricity price,and taking the minimum interaction cost between the microgrid and the distribution network as the optimization goal,an economic optimal dispatching centralized control model is established.The total charge and discharge power of distributed energy storage unit and the power purchase and sale plan can be obtained by using the beetle swarm optimization(BSO)solution model.Establishing a distributed control model with the minimum charging loss of distributed energy storage units as the optimization goal,the incremental cost consistency algorithm of the "Leader-Follower" mode is used to allocate the total energy storage power calculation in the first stage,and realize the economical optimal dispatch of the so lar-storage microgrid before the day.In the intraday rolling optimization stage,the idea of rolling optimization is adopted.Combined with the ultra-short-term forecast data of photovoltaic output and load demand,intraday rolling optimization strategies in different time periods are formulated to correct the errors of the previous scheduling plan,thus,it ensures the stable operation of the system.The correctness and feasibility of this strategy are verified by example analysis.Finally,based on the dot NET framework,an energy management platform for solar-storage microgrids is designed and developed.The platform software is written in C#,and Winform is used for interface design.There are six main functional modules,including main interface,commu nication,data storage,data processing,fault warning and system security,which can meet the needs of solar-storage microgrid monitoring,control and management.