Study On Grid-connected Photovoltaic Micro-grid Scheduling Strategy Considering The Coordination And Interaction Of Source Load And Storage

In order to deal with the problem of fossil energy shortage and environmental pollution,many countries in the world are vigorously developing renewable energy generation technology represented by distributed photovoltaic.However,due to the inherent intermittency and volatility of photovoltaic output and other unfriendly characteristics,largescale distributed photovoltaic grid-connection will bring adverse effects on the safe and stable operation of the power grid,seriously restricting the absorption level of distributed photovoltaic.In order to solve the grid-connected absorption problem of large-scale distributed photovoltaic,it is one of the safe and effective measures to connect distributed photovoltaic to power grid through grid-connected photovoltaic micro-grid(MG).Therefore,it is of theoretical value and practical significance to study the optimization operation of gridconnected photovoltaic microgrid.With the constant maturity and development of novel energy storage technology,the rapid development and application of electric vehicle(EV)technology,the continuous increase of flexible load proportion and the constant maturity of demand response technology,the dispatchable resources in grid-connected photovoltaic MG will be increasingly abundant.In view of the aforementioned development trend,this paper takes improving the local absorption rate of distributed photovoltaic and improving the operating income of grid-connected photovoltaic MG as the optimization target,and studies the optimal scheduling strategy of MG that takes into account the coordination and interaction of "source side","load side" and "storage side" scheduling resources.Firstly,this paper deeply analyzes the optimal scheduling strategy of traditional grid-connected photovoltaic MG.After that,the economic benefits in the grid-connected photovoltaic MG optimization operation are compared and analyzed,which are brought by the novel energy storage device represented by advanced adiabatic compressed air energy storage and the traditional lead-acid battery energy storage,respectively.In addition,in the face of the continuous popularization and development of EV electrical changing station,the scheduling model of EV electrical changing station is studied,and the grid-connected photovoltaic MG optimal scheduling model considering the electrical changing station of EV is established.Finally,on the basis of the research above,by considering the coordination and interaction of advanced adiabatic compressed air energy storage,gas turbine,distributed photovoltaic,EV electrical changing station and flexible load,as well as taking the uncertainty of both sides of "source and load" into account,the day-ahead real-time dispatching model of MG is established.The main research contents of this paper are as follows:(1)From the perspective of day-ahead optimization scheduling,mathematical modeling was carried out for each component of the traditional grid-connected photovoltaic microgrid,in which the state transition cost of lead-acid battery was taken into account,and the state behavior of lead-acid battery was described using the discrete variable method.By changing the battery capacity to calculate the benefits and costs of the micro grid with different energy storage capacity,the research results show that the energy storage device in the micro grid can significantly improve the utilization rate of distributed photovoltaic,reduce the configuration capacity of gas turbine,and increase the operation economy of the micro grid;(2)The paper based on the characteristics of lead-acid battery energy storage and advanced adiabatic compressed air energy storage power plant,considering the energy storage device on duty in the full life cycle of all costs,with the goal of maximizing the micro grid economical benefits in combination with specific examples,the control variable method is adopted,by the known power rating change rated capacity and the known rated capacity rating analysis of two different energy storage model for the influence of the micro grid economical benefits,have two kinds of the advantages of energy storage device rated capacity range and analyzes the formative cause;(3)The paper establishes the orderly charging model of the electric vehicle electrical changing station with the battery as the main part in the electrical changing station by analogy with the queuing theory model.On this basis,the grid-connected micro-grid economic optimal scheduling model including the electrical changing station of the electric vehicle is established.Combined with specific examples,the positive effects of electric public transport vehicles on peak load reduction,photovoltaic absorption rate improvement and energy storage configuration reduction of micro grid through electrical changing station are analyzed.The influence of the number of different charging interfaces on the micro-grid revenue is analyzed quantitatively,and the corresponding number of charging interfaces when the system revenue is saturated is obtained;(4)The paper on the basis of the above research results,comprehensive consideration of gas turbine,flexible load and advanced adiabatic compressed air energy storage device,the electric car in power station and photovoltaic power station coordination interaction,the electricity price elasticity matrix model,built a flexible load response model of price environment,and uses the triangle fuzzy number said photovoltaic,baseline load and response of flexible load forecast uncertainty has established a micro power grid-coordination scheduling model.Finally,a day-ahead real-time coordination scheduling model for the micro-grid with "source-load-storage" coordination and interaction is established to maximize the total operating income of the micro-grid throughout the day.The effectiveness of the scheduling model is verified by a specific example.