Study On Coordination Control Of Wind-photovoltaic-storage AC And DC Hybrid Microgrid

The main goal of this paper is the research of the coordinated control of AC / DC hybrid microgrid and will mainly discuss in four aspects,including the control strategy of distributed generation,the control strategy of DC microgrid,the control strategy of AC microgrid and the control strategy of AC/DC hybrid microgrid.Firstly,the control strategy of photovoltaic(PV),wind power and energy storage have been researched in AC/DC hybrid microgrid,and the mathematical model and simulation model of each micro-source are established respectively and various control strategies and characteristics of micro sources are analyzed in simulation.In the study of the control strategy of Maximum Power Point Tracking(MPPT)of PV system,a novel control strategy of MPPT based on Virtual DC Generator(VDG)is proposed in this paper,and in the research of tradition power control strategy of the PV system-constant pressure control,this paper presents an innovative control strategy-variable voltage control.Furthermore,the above two innovative control strategy are modeled,simulated and analyzed,and the advantages of the innovation control strategy proposed in this paper are pointed out.Secondly,the mathematical model of DC microgrid is established and the traditional hierarchical control of DC microgrid is analyzed.In order to overcome the shortcomings of hierarchical control,this paper puts forward variable power control of DC microgrid based on the full study of the hierarchical control and the control model is established in Matlab/Simulink.The simulation results validate the advantages of the proposed control strategy relative to hierarchical control.Then,the simulation model of AC microgrid is established,and the basic principle of traditional micro-source control strategy(such as PQ control,V/f control,droop control)in AC microgrid is analyzed,which also find the pool coordination with PV and wind power systems.Thus,the PV and wind power systems are considered to be better when use DC voltage control in AC microgrid.To realize the DC voltage control strategy,this paper improves the constant voltage control,and then puts forward the coordinated control of AC microgrid based on DC voltage control and constant pressure control,and analyzes the relationship between the island and the grid mode.Then establish the simulation model of the control strategy under the two modes of AC microgrid and analysis the simulation results.Finally,the DC microgrid and AC microgrid are connected by AC/DC bidirectional converters to form AC and DC hybrid microgrid.The control strategy of AC/DC bidirectional converter and the simulation model of hybrid microgrid are established.The change of the hybrid microgrid when the DC hybrid microgrid works in different modes and when the hybrid microgrid is switched in different modes are both simulated...