Research On Hierarchical Coordinated Controle Of AC-DC Hybrid Microgrid

The vigorous development of new energy has provided an effective and reliable way for global carbon emission reduction,microgrid technology based on this has been widely studied,and among which AC-DC hybrid microgrid has been paid more attention because it can integrate new energy generation units,energy storage and different types of loads.Based on the coordination control of AC-DC hybrid microgrid research as the breakthrough point,we have analyze the types and micro AC-DC hybrid power grid topologies and AC-DC hybrid microgrid emphasis and difficulty of the present study,and aiming at more energy storage charge in AC-DC hybrid microgrid power balance control method,not suitable for AC-DC hybrid microgrid problems,put forward a kind of based on interconnected adaptive coefficient of double droop control method of the converter,achieving energy storage and charge balance between AC and DC sub grids.In addition to meet the AC-DC hybrid microgrid power operation,based on the hierarchical control architecture is put forward a kind of coordination and control layer of pattern coordinated control strategy,implement the system stability under different operating conditions,as well as the storage charge of electricity of the balance between sub grids,improves the hybrid microgrid power supply reliability.The specific organization structure of this paper is as follows:Firstly,this paper classifies the AC-DC hybrid microgrid topology according to different microgid organization modes and differences in the placement locations of energy storage units,analyzes the characteristics of different topological structures and research emphases,on this basis,the shortcomings of realizing the charge balance of each sub-net energy storage unit in the existing coordinated control research are studied,then,based on the single-type distributed energy storage topology structure of AC-DC hybrid microgrid,a sub-mod coordinated control strategy with joint and independent operation state is designed.Secondly,in view of the problem of insufficient inter-network charge in the existing AC-DC hybrid microgrid,it is analyzed the existing droop control method of multiple energy storage and charge in a single type of microgrid that cannot be directly applicable to AC-DC hybrid microgrid,on this basis,an adaptive coefficient double droop control method for ILC is proposed,each sub-net in the AC-DC hybrid microgrid shares the load proportionally according to the amount of energy storage unit,so as to achieve the goal of balance of charge and electricity between networks.Finally,considering the complex operating conditions of AC-DC hybrid microgrid,and the adaptive double-droop control method cannot achieve the balance of energy storage and charge under various operating conditions,a sub-net coordinated control method is designed,the coordinated control layer determines the current system operation mode and calculates the power transmission of the underlying ILC by collecting operation parameters of each unit in the sub-net,in the joint state,the AC and DC sub-net achieve power mutual aid、balance of energy storage and charge,in the independent state,AC and DC sub-net achieve internal power balance through MGCC.The effectiveness of the proposed coordinated control strategy is verified by building a mode on MATLAB/Simulink platform in the end.