SOFT-START SINGLE-PHASE FREQUENCY-LOCKED LOOP WITH DC COMPONENT REJECTION CAPABILITY
Aiming at the problem that the traditional frequency-locked loop cannot reject the DC component of grid voltage,a frequency-locked loop structure based on DC component rejection loop is proposed.In order to improve the dynamic performance of the frequency-locked loop during startup stage and phase angle jump condition,the traditional frequency-locked loop structure is improved to reduce the gain of the frequency estimator loop,achieving fast and smooth phase angle tracking.Finally,a soft-start up single-phase frequency-locked loop which can reject DC component of grid voltage is proposed.Simulation analysis and experimental results show that the proposed structure has good steady-state and dynamic characteristics.
PV power generationfrequency estimationsynchronizationDC component rejectionsoft-startup