AN AC Micro-grid Controlled By Hierarchical Control

Due to the adverse effects of using fossil fuels to generate electricity and the proportion of harmful gases produced in the environment,we are now seeing a broad trend of using renewable energy to generate electricity.This article takes microgrid a convenient model for using renewable energy as the research object.This article discusses the microgrid(which is a convenient model for using renewable energy)and defines the microgrid and its structure in detail.In addition,it also includes operating modes and microgrid classification.Likewise,it provides information about power electronic devices especially power converters in the microgrid.In addition,it explains the hierarchical control system and its role in maintaining the reliability and stability of the microgrid system.The hierarchical control scheme is divided into three levels.The first stage is the main stage,mainly used for the sharing of active and reactive power,including the voltage drop control scheme.The second layer is responsible for eliminating the steady-state error generated by the first layer.Finally,the third level manages the power flow between the microgrid and the main grid.