Micro-grid Economic Dispatch Considering Power Uncertainty And Variability Of Renewable Energy Sources

With the rapid development of smart grid,micro-grid provide integration platform for distributed generations,which possess great benefit of technique,economic and environment.For the influence of the power uncertainty and variability of renewable energy sources it is hard to guarantee the schedule-ability,stability and economic of micro-grid.It is necessary to include spinning reserve and coordinate the adjustable unit in micro-grid to conduct economic dispatch to realize reliable and economical operation of micro-grid.To decrease the impact of the power uncertainty and variability of renewable energy sources,chance constraint condition of reserved power is introduced in micro-grid economic dispatch in this dissertation.And sequence operation theory was adopt to establish model for the uncertain variables to deal with the chance constraint condition efficiently.And research was carried out about grid connected micro-grid and isolated micro-grid.Firstly,the uncertainty model of load and renewable energy sources power prediction was established.And probabilistic sequence was adopt to describe the united discrete probability distribution of wind,photo-voltaic and load power prediction error,which laid the foundation of considering the power uncertainty of renewable energy sources in the schedule model.Secondly,the dispatch models of micro-turbine,battery,shift-able load,spring load and interrupt-able load were proposed.And the discharge depth model of the battery was improved to describe the charging and discharging cost of battery more reasonably.Next,considering the power uncertainty of renewable energy sources,the day-ahead economic dispatch model of grid connected micro-grid and isolated micro-grid was researched.And the short-term scroll scheduling model within day was established to conduct multi-time scale dispatch to further reduce the impact of power prediction error.Moreover,the paper integrated renewable energy sources power uncertainty into dispatch model in the way of spinning reserve constraint using chance constraint theory.And the TOU power price was considered in the grid connected micro-grid dispatch.The interaction of demand-side flexible load was included in the isolated micro-grid dispatch.Meanwhile,the dispatch model was established in the goal of minimizing system operation cost considering economic,environment and reliability.Finally,the PSO algorithm was combined with the GA algorithm in this paper to improve the convergence performance of the optimization algorithm.Meanwhile,expert experience logic strategy was introduced to amend the optimal solution.Moreover,several variables was decoupled before optimization.Additionally,partly small step random search was conducted taking the power unbalanced time frame as center.And special swarm was set for spinning reserve demand and unbalanced power.The proposed model and method was analyzed and verified by micro-grid cases.The results indicate that the model can decrease impact of the power uncertainty and variability of renewable energy sources,and simultaneously ensure the micro grid operate economically.And this solution can be helpful for the economic dispatch of grid connected micro-grid and isolated micro-grid.