Optimal Operation Method Of AC/DC Hybrid Microgrid Considering Different Operation Modes

The economic dispatch of microgrid is an important subject, the purpose of which is to meet the load power demand and at the same time to optimize the comprehensive cost, it is the key to the economic benefits of microgrid. AC/DC hybrid microgrid provides a convenient platform for grid connection and management of DC load and DC micro sources, which makes its optimization operation gradually become an important issue. AC/DC hybrid microgrid has the unique advantages compared with the traditional AC microgrid. It can improve the control efficiency, reduce the line loss,improve the power quality, and provide a convenient platform for DC load access. The traditional AC microgrid has only two types of operation modes: grid connected operation and off grid operation, however AC/DC hybrid microgrid has much more flexible and diverse operation modes therefore the influence of different operation modes and the switching between modes should be considered in the optimization operation.According to the more complex and diverse operation modes of AC/DC hybrid microgrid than traditional AC microgrid, considering the economic cost and environmental cost, that is the minimum operation cost of AC/DC hybrid microgrid was taken as the objective function, while the AC and DC DC power balancing constraints etc. were considered, the optimal operation model was established. The proposed model is more applicable because of the different operation modes of AC/DC hybrid microgrid are covered in practical applications. On this basis, the integrated optimal operation model under the expected mode switching and the unexpected mode switching was established respectively to ensure the optimal efficiency of the AC/DC hybrid microgrid under mode switching. The particle swarm optimization (PSO) algorithm was improved by introducing the chaotic search, then the improved chaotic particle swarm optimization algorithm was used to design the solution flow. The simulation results show that the optimized operation results of AC/DC hybrid microgrid under different operation modes have great difference; When the AC/DC hybrid microgrid operates was under the mode switching mode, The optimized operating index in predictable mode switching was better than that in the unexpected mode switching. The model is able to fully consider the influence of different operation modes in actual operation, and ensure the economical performance of AC/DC hybrid microgrid and more adaptive.