Research On Optimal Dispatching Method Of Multi-energy Containing Wind/Photovoltaic/Thermal And Storage Systems

High penetration of renewable energy integration is an inevitable trend and strategic needs for global energy development,which poses great challenges to system stability,economy and power quality.Joint operation of multiple renewable energis as well as energy storage forms is one of the critical issues to eliminate the negative effects.Therefore,this thesis analyze the complementarity characteristics of wind and photovoltaic(PV)output,and carry out the optimal dispatching method of multi-energy system containing wind,PV,thermal,hydro-pumped and battery storage.Main contributions include:(1)Joint probability distribution model of wind and PV output is established based on Copula theories.Three methods including pattern comparison,rank correlation coefficients comparison and squared Euclid distance comparison are utilized to select the appropriate 5 Copula model from,which is of great importance to provide data input for subsequent research.Simulation results indicate that normal Copula model could best fit the actual wind and PV output,so as to better describe the complementarily characteristics of wind and PV output.(2)Based on both actual output data and prediction data,two kinds of wind and PV output reliability models,including improved two-state reliability model as well as continuous reliability model are established.Furthermore,operational credit capacity calculation method is proposed to provide the decision-making conditions for multi-energy optimization scheduling.Simulation results indicate that the operational credit capacity based on continuous reliability model could better reflect the influence of prediction errors on the credit capacity of power system,which is beneficial to estimate the available capacity of wind and PV in advance,and is of certain reference significance to make dispatching plan.(3)On the base of traditional cost model,ramping and low-load operational cost is added to establish an improved cost model that is more suitable for actual operational thermal power units.Multi-energy system in the cooperation of wind,PV,thermal,hydro-pumped and battery storage are optimized to make day-ahead scheduling strategies and realize the comprehensive and efficient utilization of renewable energies.Simulation results indicate that the improved cost model for thermal power units could more veritably quantify the incremental cost caused by peak-shaving operation,and more flexibly balance the contradictions between curtailments and the increased operational costs,so as to provide much more economic scheduling strategies for decision makers.