Research On Multi Time Scale Energy Optimal Dispatch Of Microgrid Considering Uncertainty

In recent years,the increasing depletion of conventional fossil energy,the increasingly serious problem of environmental pollution,and the large power grid problems of power system structure aging,low efficiency of energy utilization and power supply,make the development and utilization of renewable energy,such as wind power,photovoltaic and other renewable energy,and the construction of sustainable energy system an inevitable trend of development.Microgrid is a controllable unit that combines wind power,photovoltaic and other renewable energy,load,energy storage,control and protection devices together,which can improve the efficiency of the use of traditional and renewable energy.However,due to weather factors,the output of renewable energy such as wind power and photovoltaic is uncertain.The access of high permeability renewable energy to microgrid will increase the operational risk and bring great difficulties to the optimization and operation of the system.How to adapt to the uncertain characteristics of various renewable energy sources and realize the orderly interaction of all kinds of energy sources is the key to the optimization and operation of the microgrid.The conventional deterministic operation scheduling strategy of microgrid can not well adapted to the uncertainty of renewable energy output.Therefore,based on the uncertainty theory,this paper studies the optimal scheduling problem of microgrid considering the uncertainty of high permeability renewable energy.The main work includes:(1)Based on the uncertainty theory,a normal uncertainty mixed model of wind and photovoltaic power output prediction error is established according to the characteristics of the uncertainty of wind and photovoltaic power generation,so the wind and photovoltaic power output are treated as uncertain variables and the uncertain distribution model of wind and photovoltaic power output is obtained.(2)A day-ahead scheduling model of the microgrid is established.The uncertain measure of the uncertainty theory is used to describe the occurrence probability of uncertain events.And combines with chance constrained programming,an uncertain constrained optimal scheduling model for microgrid is proposed.The model can effectively describe the optimal scheduling problem of microgrid with double uncertainties of wind and photovoltaic power.A hybrid intelligent algorithm combining genetic algorithm with uncertain simulation is proposed to solve the model.(3)A day rolling correction model of the microgrid is established.According to the characteristics of short time scale output of each power source,a multi-objective function model of day rolling correction is established with the target of minimum power supply adjustment and minimum adjustment cost.And a nonlinear programming genetic algorithm combined with genetic algorithm and nonlinear programming is proposed to solve the model.(4)Example analysis and verification.The effectiveness and rationality of the proposed multi time scale energy optimal dispatching model and the model solution algorithm proposed in this paper are verified by a specific example.The day-ahead scheduling part and the day rolling correction part constitute the multi time scale optimal scheduling strategy of microgrid,the optimal scheduling of micro grid energy,which realize the energy optimal scheduling of microgrid.