Energy Management Of Hybrid AC/DC Microgrid

Microgrid has great potential in improving energy efficiency,power system reliability,flexibility and environmental protection.It has been a hot topic in power system research.Among them,hybrid AC/DC microgrid which effectively combines the advantages of AC microgrid and DC microgrid has become to be an inevitable trend of future development.However,the existing research on the microgrid energy management is mainly aimed at the AC microgrid.What's more,most of the optimal objectives focus on the operating costs minimization or pollution emissions minimization,etc.,which does not take the cost and loss of converters in microgrid into consideration.For hybrid AC/DC microgrid,the cost and loss of the converter will directly affect the energy flow between the AC and DC regions.Therefore,in order to make the operation of hybrid AC/DC microgrid economy,high efficiency and less loss,it is very important to optimize the energy in the hybrid microgrid.In this paper,the energy management of hybrid AC/DC microgrid is systematically studied from the information input side,the power supply side and the demand side respectively.The main work is as follows:Firstly,the current research status of microgrid and microgrid energy management is summarized.The structure of hybrid AC/DC microgrid is introduced,and the theoretical analysis and mathematical modeling are carried out for each unit.Secondly,the output power of renewable energy in the input layer of hybrid AC/DC microgrid energy management information is forecasted by modified particle swarm optimization-back propagation.Aiming at the slow convergence of BP neural network,and the problem of particle swarm optimization algorithm is easy to fall into the local extremum,the proposed method can adaptively adjust the weights of the improved particle swarm optimization on BP,and the example simulation results show that using the proposed algorithm to predict the output of renewable energy power has a faster convergence rate than the basic algorithm,and the prediction accuracy is higher,which proves the effectiveness of the proposed algorithm.Then,the power supply side in hybrid AC/DC microgrid energy management is studied.The optimal scheduling is completed based on the characters of different distribute resources.A multi-objective optimization model is established to study whether the converter cost and its loss are taken into account on the optimal scheduling results.The simulation results show that the proposed strategy not only can reduce the loss of the converter in the system,but also improve the overall economic performance,more practical significance.Finally,the load demand side in hybrid AC/DC microgrid energy management is studied.The importance of the demand side participation optimization is expounded.Then the load is classified and analyzed by the translational load model.Finally,the demand of the AC/DC hybrid microgrid energy management is optimized.The simulation results show that controllable load to participate in the optimization of scheduling not only greatly improve the operation of the microgrid economy,but also on the microgrid safe and stable operation is of great significance.