Research On AC/DC Bus Voltage Stability Control Of Hybrid Microgrid Based On Switched System

With the application and development of new energy power generation technologies and distributed power systems,the research on microgrids has become a current research hotspot.Among them,AC and DC hybrid microgrids have the comprehensive advantages of AC and DC microgrids.Research on microgrids is of great significance.The AC/DC two-way power converter can realize the two-way flow of power between AC and DC microgrids in the hybrid microgrid,and plays a key role in maintaining the power balance between the AC microgrid and the DC microgrid and the stability of the AC and DC bus voltage.DC bidirectional power converter occupies an important position in hybrid microgrid structure.Based on the switched system theory,this thesis combines backstepping control,improved adaptive backstepping control and sliding mode control to study the AC and DC bus voltage stability control of hybrid microgrid.The main work is as follows:(1)Aiming at the stability of the AC/DC bus voltage during the switching operation of the hybrid microgrid,this thesis proposes to apply the switching system control theory to the stable control of the AC/DC bus voltage of the hybrid microgrid,and establishes the switching system model of the hybrid microgrid.(2)The backstepping method is used to design a stable controller for the AC/DC two-way power converter to ensure that the AC/DC two-way power converter can achieve stable control of the DC bus voltage and the AC bus voltage when the hybrid microgrid is operating in mode switching.(3)Aiming at the problem of unknown parameters in the hybrid microgrid,a stable controller is designed for the system by combining improved backstepping control and adaptive control to ensure the stability of the AC and DC bus voltage during the switching operation of the hybrid microgrid.(4)Comprehensively considering the unknown parameters and unknown disturbances in the hybrid microgrid,the improved adaptive backstepping control and sliding mode control are used to design a stable controller for the hybrid microgrid system,which ensures the voltage stability of the AC and DC bus during the switching operation of the hybrid microgrid and enhances the robustness of the system.