Reasearch On Islanding Detection Methods In Single-phase PV Grid-connected System

The number of traditional energy has become tighter,and the environmental pollution is gradually increasing,so renewable energy is subject to people’s attention.Among them,the solar power technology has been developed by leaps and bounds.Based on single-phase PV systems,this paper researches the grid-connected strategy,islanding detection and blind area analysis.In this paper,firstly,the model of the grid-connected about PV system is built by using the current instantaneous value hysteresis comparison method,the double loop feedback control strategy and the filter design,and it is analyzed by the simulation.Secondly,this paper briefly introduces the several islanding detection methods,analyses the basic principle and the blind area distribution of the active frequency shift method and the improved double loop positive feedback active frequency shift method,and draw the distribution of its blind area.Finally,based on the grid-connected model of single-phase PV power generation system,this paper establishes the islanding detection model of active frequency shift method and the improved double loop positive feedback active frequency shift method,and carries on the simulation analysis to the model.The simulation results show that,from the time of the islanding detection,the improved double loop positive feedback active frequency shift method is better than the active frequency shift method.