Research On System Optimization And Energy Scheduling Of AC/DC Hybrid Microgrid

With the development of power electronics technology and the maturity of renewable energy generation technology,microgrid technology has been widely concerned in the world.The AC/DC hybrid microgrid,which coexists AC/DC power supply and AC/DC load,integrates the advantages of DC microgrid and AC microgrid,can effectively utilize the advantages of distributed generation,improve its own stability and reduce the impact on the main power grid,and has become one of the development trends of microgrid.In this thesis,the system optimization design and energy optimization scheduling problem of a typical AC/DC hybrid microgrid are studied,the main contribution are as follows:An optimization method of AC/DC hybrid microgrid system based on ILC power control is proposed.In view of the unique "grid-to-grid" control in AC/DC hybrid microgrid and the effect of ILC on the power distribution of AC and DC subnets,the voltage transferred between AC/DC subnetworks is regulated by controlling the capacitor voltage of ILC in the intermediate link,so as to maintain the power balance on both sides.The simulation results show that the proposed ILC power is more effective than the traditional control power in maintaining the stability and controllability of the system in the grid-connected mode and the isolated mode.Improvement of GOA algorithm.To solve the problem of lack of randomness in the original GOA algorithm,on the one hand,the Tempered Levy Flight random walk strategy can effectively avoid the dilemma of local optimization.On the other hand,by adjusting the parameters to control the search space,improve the global search ability.The simulation results show that the improved GOA algorithm is superior to the original GOA algorithm no matter it is single-peak function,multi-peak function,low-dimensional function or high-dimensional function,which shows that the improved GOA algorithm has better performance and better ability to jump out of the local area.A demand response based on electricity price is proposed to establish a real-time electricity price model.According to the economy,environmental protection and autonomy of AC/DC hybrid microgrid,the optimal scheduling models are established respectively,and the model is solved by combining with the improved GOA algorithm.Case analysis of the intermittent output of distributed power supply situation,consider the supply side and demand side optimization at the same time,through the original price and real-time price model,the experimental results also show that micro ac/dc hybrid power grid load curve obtained reasonable optimization,wind-light utilization has significant improvement,system economy,environmental protection and autonomy are improved.Further broaden the application scenarios of hybrid microgrid,and study the uncertainty in hybrid microgrid.The Conditional Value at Risk(CVa R)theory was introduced to quantify the Risk penalty cost caused by the randomness of landscape output,and the uncertain load model was established.The method of scene generation and reduction is used to describe the random characteristics of renewable energy output,and MATLAB/CPLEX is used to solve the problem,which effectively improves the operating economy of the system and the generality of the established model.