Research On Multi Microgrids Game Dispatch Considering Power Unbalance And Risk

In recent years,with the rapid development of microgrids,they can be predicted that multiple microgrids will be connected to the distribution system in the future,forming a distribution system with multiple microgrids.With the further concretization of power reform,microgrids can not only trade electric energy with distribution system,but also trade electric energy between microgrids.The distribution system with multiple microgrids has multiple stakeholders.Game theory can effectively solve the interest divergence of multi-agent.Using game theory to study the optimal scheduling of distribution system with multi micro grid has certain economic significance.With the micro grid access to the distribution system,it brings certain economic and environmental benefits,but the access of micro grid makes the system structure change.At the same time,the randomness of the output of distributed power in the micro grid increases the operation risk of the distribution system.It is of practical significance to evaluate the risk of distribution system with multiple microgrids,find out the weak points of the system,and accurately reveal the risk.First of all,this paper proposes a Cumulant method based on Cornish Fisher series to solve the stochastic power flow of distribution system with multiple microgrids,and calculates the probability density function of node voltage and branch power flow exceeding the limit;uses utility theory combined with the exceeding limit offset to express the severity function of node voltage exceeding the limit and branch power flow exceeding the limit;calculates the risk index of system level voltage exceeding the limit and power flow exceeding the limit quantitatively Limit the risk index,study the impact of multi microgrid on the distribution system after different access points and different ratio of wind and solar capacity are connected.The correctness of the risk assessment model and the high efficiency and accuracy of the proposed algorithm for the risk assessment of micro grid distribution system are verified by MATLAB simulation.Secondly,this paper establishes a two-level game scheduling model withmultiple microgrids,and considers the influence of the output of controllable generation units in microgrid.The upper level game is a game scheduling model considering the risk cost of electricity price transaction between microgrid and distribution system;the lower level game is a game scheduling model with multiple microgrids about power loss cost.Finally,based on the unbalanced power of each microgrid,the rules of electric energy transaction including multi microgrid distribution system are established to ensure the normal and orderly electric energy transaction between microgrids,microgrids and distribution system.The upper level game is solved by the method of pre order traversal strategy;the lower level game is solved by particle swarm optimization algorithm,and the multi microgrid access to ieee-33 node system is used for example analysis to verify the rationality of the two-level game scheduling model and the effectiveness of the algorithm.