Research On Optimal Operation Of Multi-Element Complementary AC/DC Hybrid Microgrid

With the wide application of renewable energy,the types of distributed generation and load gradually increase,and microgrid is developing rapidly.Hybrid AC/DC microgrid integrates the advantages of AC microgrid and DC microgrid at the same time,which can better adapt to the access of different types of distributed generation,meet the increasingly complex power supply and demand of the power system,and effectively promote the consumption of renewable energy.Therefore,it has become one of the inevitable trends of microgrid technology development.In the hybrid AC/DC microgrid,the "source-grid-load-storage" coordinating interaction can be realized through the coordination of various distributed elements.This paper focuses on the optimal operation of multi-element complementary hybrid AC/DC microgrid.Firstly,the development trends of hybrid AC/DC microgrid at home and abroad are expounded.The research status of the optimal operation is summarized.The multi-element complementary characteristics and mechanism of hybrid AC/DC microgrid are analyzed respectively from both supply side and demand side,which clarifies the important role of all kinds of distributed elements in maintaining the power balance within the microgrid.Then,mathematical models of distributed generation and energy storage battery in microgrid are established respectively.Considering various constraints of the microgrid,the optimal operation model of the multi-element complementary hybrid AC/DC microgrid under the grid-connected mode and island mode are established respectively aiming at minimizing the integrated operation cost.Due to the whale optimization algorithm is easy to fall into local optimum,combining with the chaos search strategy,a chaotic whale optimization algorithm is proposed to solve the model.Better performance of the proposed chaotic whale optimization algorithm in solving the optimal operation problem of hybrid AC/DC microgrid is proved compared with the other common intelligence algorithm.On the basis of actual calculation example of 863 demonstration project,chaotic whale optimization algorithm is used to solve the optimal operation model of hybrid AC/DC microgrid in grid-connected mode and island mode respectively.The optimal operation scheduling scheme with integrated operation cost of microgrid is obtained.The scheme gives full play to the multi-element complementary characteristics of hybrid AC/DC microgrid and the economic and stable operation of microgrid can be realized by the cooperation o f distributed element such as wind power,photovoltaic,energy storage and interruptible load.