Multi-scale Dynamic Optimization Scheduling Of Independent Microgrid

Wind energy and solar energy are clean energy sources with the characteristics of environmentally friendly,non-polluting,rich in reserves and widely distributed,so distributed power generation technology that uses wind energy and solar energy as its main energy sources has received extensive attention from scholars at home and abroad.The microgrid can not only effectively solve the problem of distributed power plant sites,but also use other devices such as batteries to stabilize the power fluctuations of the microgrid system and weaken the adverse effects of the random fluctuation characteristics of clean energy to the stability of the microgrid system.This paper mainly studies the problem of frequent start and stop of micro gas turbines in the process of independent microgrid scheduling and the unreasonable connection between scheduling scales in the micro-scale multi-scale scheduling process.The corresponding optimization method is proposed.The established independent micro-grid system model is solved and verified by the combination of “MATLAB+YALMIP+GUROBI”.The main research work of this paper are as follows:(1)Establish a multi-scale scheduling model of microgrid combined with short-term scheduling and ultra-short-term scheduling.In the short-term scheduling stage of microgrid,a micro-grid short-term optimization scheduling method based on feedback correction is proposed for the frequent start-stop problem of micro gas turbines in the microgrid scheduling process.The feedback correction of the micro gas turbine operation plan is implemented by short-term scheduling.Thereby,the number of start and stop of the micro gas turbine is reduced,and the operating state of each micro power source is optimized.In order to optimize with the proposed optimization method,the battery partition model is used to control the battery,so that the battery can be fully utilized while meeting the system requirements.(2)In the ultra-short-term scheduling stage of microgrid,aiming at the coordination problem between scheduling levels in the multi-scale scheduling process of microgrid,an ultra-short-term optimal scheduling method based on over-limit penalty is proposed.In the ultra-short-term scheduling phase,the short-term operation plan of each micro-power supply is corrected,and the over-limit penalty cost function is established to limit the correction amount,forcing the ultra-short-term scheduling plan to be adjusted within a certain range of the short-term scheduling plan,reducing the deviation between the two-level scheduling schemes,reducing the regulation pressure of the equipment and enhances the correlation between different scheduling scales in the multi-scale scheduling system of the independent microgrid.(3)In the MATLAB environment,the YALMIP software is used as the interface,and the GUROBI optimization software is used as the optimization solver to simulate and verify the multi-scale scheduling model and optimization method of the independent microgrid.The simulation results of the system are analyzed.The verification results show that the independent microgrid feedback correction dynamic optimization scheduling method based on the over-limit penalty enhances the connection between time scales.The problem of excessive adjustment of the system equipment and frequent start and stop of the micro gas turbine is solved,and the reliability of the power supply of the micro grid is also greatly improved.