Research On Coordinated Optimal Dispatch Of Microgrid Based On Demand Side Response

In recent years,in order to better protect the environment and meet people’s increasing demand for electricity,renewable energy sources have been widely used in the power sector.The proposal of the microgrid concept solves the grid connection problem caused by the intermittency of renewable energy power generation.In addition,in order to reduce the negative impact of the greenhouse effect on humans,and to ensure people’s thermal comfort needs for life,work and other places,a large number of air conditioning equipment is used intensively in summer,which brings challenges to the stable operation of the power grid.Although the emergence of electric vehicles has alleviated the greenhouse effect to some extent,its large-scale random charging has also increased the pressure on the operation of the power grid.To solve the above existing issue,this thesis considers the air conditioning load and electric vehicles as part of the microgrid,allowing the two parties to participate in the demand side response,and studies the optimal dispatching of the microgrid.Firstly,in response to the problem of air conditioning load participating in demand side response,a microgrid system including photovoltaic power generation system,energy storage battery,air conditioning load and uncontrollable load is proposed.Subsequently,equivalent mathematical modeling of photovoltaic power generation system,energy storage battery and air conditioning load is carried out to be used as the basis for subsequent research on optimal dispatching of microgrids.Among them,the modeling process of air conditioning load as a response resource on the demand side is introduced in detail.Secondly,for the split fixed frequency air conditioners studied in this thesis,a demand side response scheme combining price-based demand side response and direct load control,and a control method that the load aggregator directly controls their start/stop state by the remote control equipment,are proposed to manage their operation status.In addition,to more clearly describe the effect of indoor temperature on the thermal comfort of users,a thermal sensation voting model is adopted.Then,starting from the dispatch goal of the economic operation of the microgrid,an optimal dispatching model of the microgrid with air-conditioning load based on mixed integer linear programming is established.Through the above control methods and models,under the condition of ensuring the thermal comfort of users,the optimal coordinated control of air conditioning load and energy storage battery is realized.Thirdly,as another type of demand side response resource,electric vehicles are added to the microgrid which contains air conditioning load,forming a coordinated optimal dispatching problem of air conditioning loads and electric vehicles.After adding the relevant constraints of electric vehicles,a new microgrid economic dispatch model has been formed.Aiming at the errors in photovoltaic output forecasting and load forecasting,as well as the uncertainty of electric vehicle travel rules,the probability distribution function is used to describe these errors and uncertainties.In order to reduce the influence of forecasting errors and uncertainties on the accuracy of scheduling results,a two-stage optimal scheduling strategy including day-ahead scheduling and real-time scheduling is proposed.Finally,the results of the experimental simulation prove that taking the air conditioning load and electric vehicles as part of the microgrid to participate in the demand side response,can reduce the operating cost of the microgrid and the operating pressure of the distribution network while ensuring the thermal comfort of users and the needs of vehicle owners.In addition,by using real-time scheduling strategies to modify and adjust the results of the day-ahead scheduling,the scheduling results can be closer to reality.