A robust voltage and current controller of parallel inverters in smart island: A novel approach

摘要

Smart Island (SI) refers to the condition where distributed generation (DG) units e.g.wind turbines (WT),fuel cell (FC),and photovoltaic cells (PV) have to control current,voltage,and frequency of the grid by themselves without any support from the main grid.Therefore,design and implementation of robust controller to overcome disturbances and load variations is very crucial.This paper presents a new approach using General Type-Ⅱ Fuzzy controller to control smart island in combination with a novel modified optimization algorithm to increase the load sharing throughout the DGs operating in an islanding mode.This case study assumes that there are two DGs in the smart island where each DG has its own responsibilities.In particular,one of the DGs regulates the frequency and voltage based on a reference feedback,while the other DG operates in load current control mode to share load between each DG properly.The simulation results indicate that the suggested controller has a quick response to load alternations with a low steady state error and low THD.Moreover,the proposed controller is independent from system states and other units.The experimental analysis indicate that the suggested control system is effectively capable to coordinate the operations of the DG units in smart island to validate the stable operation of the overall smart island.