Title :
A single-phase grid synchronization method based on frequency locked loop for PV grid-connected inverter under weak grid
Author :
Yulin Yang ; Guihua Liu ; Hongpeng Liu ; Wei Wang
Author_Institution :
Dept. of Electr. Eng. & Autom., Harbin Inst. of Technol., Harbin, China
Abstract :
One of the main electrical characteristics of weak grid is high grid impedance, which will easily lead to harmonic resonance and grid voltage waveform distortion. Distorted grid voltage can make the phase-locked loop of photovoltaic (PV) grid-connected inverter occur deviation even failure and power quality deteriorates. Aiming at the problem, this paper takes the LC-type PV power generation system as study object, studies the effects on system of different grid conditions, adopts a second-order generalized integrator frequency-locked loop(SOGI-FLL) grid synchronization method under weak grid to realize grid-connection securely and improve the grid current quality. Finally the simulation and experimental results are given to demonstrate the validity of the proposed method applying to the single-phase PV power generation system under weak grid.
Keywords :
electric power generation; frequency locked loops; invertors; photovoltaic power systems; power grids; power supply quality; synchronisation; LC-type PV power generation system; SOGI-FLL; frequency locked loop; grid current quality; grid voltage waveform distortion; harmonic resonance; photovoltaic grid-connected inverter; power quality; second-order generalized integrator; single phase grid synchronization; weak grid; Frequency locked loops; Harmonic analysis; Impedance; Inverters; Phase distortion; Phase locked loops; Synchronization; FLL; PV gird-connected power generation; weak grid;
Conference_Titel :
Intelligent Control and Automation (WCICA), 2014 11th World Congress on
DOI :
10.1109/WCICA.2014.7053646