Research On Wind-solar-storage Microgrid Energy Management System Optimal Control Method

With the increasing proportion of renewable energy power generation,the scale of wind power generation and photovoltaic power generation connected to the large power grid is constantly expanding.However,wind power generation and photovoltaic power generation fluctuate greatly under the influence of environmental factors,which will not only reduce the reliability of power supply for surrounding users,but also impact the large power grid.At this point,energy storage and adjustable load need to be used to assist renewable energy and form a microgrid system to connect to the large power grid.Microgrid is equivalent to a friendly load for large power grid.However,the randomness of renewable energy power and load power inside microgrid is strong,which leads to complex and changeable situation in the operation process of microgrid.In this paper,based on the prediction of the renewable energy power and load power of the microgrid,the optimization algorithm is adopted to make the scheduling plan for the microgrid so that it can run according to the set target.In this paper,the optimization process of wind-solar-storage microgrid energy management is taken as the research object.Firstly,the prediction of renewable energy power and load power in the microgrid is analyzed to study the realization of the power prediction process.the prediction results obtained by different prediction algorithms are analyzed and compared to determine the prediction algorithm adopted in the optimization process of the microgrid energy management.Contrapose the problem that the result of microgrid scheduling plan depends on the accuracy of power prediction,a multi-time scale optimization strategy was established for microgrid.After the day-ahead scheduling plan was formulated on the basis of dayahead power prediction,the intraday scheduling plan was formulated on the basis of intraday scheduling plan according to the power data of intraday rolling prediction.At the same time,aiming at the serious problem of life loss caused by the deep discharge of energy storage in the microgrid optimization,the objective function of energy storage life optimization is established,and the optimization of energy storage life is taken into account while making the scheduling plan for the microgrid.In day-ahead scheduling,NSGA-II optimization algorithm is adopted to formulate day-ahead scheduling plans for microgrid off-grid and grid-connection,respectively,based on day-ahead prediction data of renewable energy power and load power.The dayahead optimization goal for microgrid off-grid is to optimize economic benefits and minimize load loss rate.The objective of day-ahead optimization in grid-connected operation is to optimize economic benefit and minimize peak-valley difference of tie line power.The day-ahead optimization results of the micro-grid are obtained through simulation,which verifies the feasibility of day-ahead optimization scheduling and provides a foundation for the later intraday optimization scheduling.In intradays schedule,based on renewable energy power and power load days rolling forecast data,with the improved particle swarm optimization algorithm in micro grid has based on the results of optimization for day-ahead optimization,the micro grid off-grid time optimization goal within the micro power source power change minimum and achieve the maximum use of renewable energy power,The optimization objective of the microgrid is to minimize the changes of the energy stored power and the power of the tie line during the period of grid connection.The intraday optimization results of microgrid are obtained by simulation.