Bi Level Optimization Of Multi Microgrid And Active Distribution Network Considering Demand Response

One of the effective ways to realize the transition from traditional power grid to smart grid is to connect microgrid to distribution network.Microgrid is a small power generation and distribution system including distributed generation(DG).Integrating DG into distribution network in the form of microgrid can promote renewable energy consumption and improve power reliability of microgrid.From the perspective of microgrid,in order to improve the utilization rate of renewable energy,multiple microgrids can be formed into microgrid groups to help each other with surplus electricity,or microgrid and active distribution network(ADN)can trade electricity.With the reform of the power market,the user side can more actively participate in the dispatching of the power system,which not only enables users to consume according to their own needs,but also enables the power system to coordinate energy management and operation control from both sides of the source and load,which meets the development needs of the active distribution network.Therefore,based on the bi level optimization method,this paper studies the grid connected multi microgrid optimal scheduling problem and the adn scheduling problem with multi microgrid access from both supply and demand sides,and the specific work is as follows:Firstly,from the energy supply side,multiple microgrids are considered to form a microgrid cluster system.The microgrids are used as standby energy for each other,and the microgrid cluster is connected to ADN for power trading.At the same time,the optimization scheduling model of grid connected microgrid cluster and the ADN optimization scheduling model based on optimal power flow are established,The power of tie line is used as coupling variable for two-level optimization.Secondly,considering from the demand side,the flexible load is regarded as a controllable scheduling unit according to the load demand of different types of microgrid users,with the objective of minimizing the total power regulation cost,the scheduling scheme of each sub microgrid is optimized by combining two incentive based demand side response modes,interruptible and transferable,and according to the trading power,whether the microgrid group is connected to ADN system as virtual power or virtual load is determined.The lower model uses the consistency algorithm to transform the economic dispatch problem into the cost consistency problem in the process of power allocation to solve the model.The upper model takes the minimum network loss as the goal,considers the lower tie line constraints and power flow constraints,and uses the second-order cone technology and gurobi solver to solve the DG output of ADN system.The simulation results show that the demand side response can cut the peak and fill the valley of the load curve,and improve the system economy and energy efficiency.The energy exchange between micro networks can help the micro grid group to achieve cost consistency power regulation,which can reduce the cost of power regulation while ensuring the real-time power balance of the micro grid group.Meanwhile,the dual optimization strategy of micro network group and adn system can promote renewable energy consumption,and make both sides achieve mutual benefit.Finally,from the perspective of source load interaction,the optimal scheduling of integrated energy multi microgrid is studied,and a bi level optimal scheduling model of multi microgrid and ADN based on integrated demand response is established.Based on the characteristics of complementary and interchangeable energy in the integrated energy microgrid,the lower multi microgrid is divided into two stages: power load response based on time of use price and heat load response based on incentive.The optimal output of each unit is determined with the objective of minimizing the total cost of the system in the dispatching period,and the two-stage scheduling model is solved by whale optimization algorithm.The optimal trading power of the lower multi microgrid is used as tie line to participate in the upper optimization,while the upper one is the ADN optimal scheduling model based on optimal power flow,and the second-order cone relaxation technique and gurobi solver are used to solve the model.The simulation results show that the implementation of the integrated demand side response strategy can make the multi microgrid coordinated scheduling according to the energy supply characteristics of electric and thermal loads,realize the optimal utilization of energy,and make the multi microgrid system more economical.