Frequency- adaptive control of a three-phase single-stage grid-connected photovoltaic system under grid voltage sags

The low-voltage ride-through service is carried out in this paper according to the voltage profile described by IEC 61400-21 European normative when short-duration sags happen, and some instantaneous reactive power delivered grid accordance with Spanish code; mandatory limitation of amplitude three-phase inverter currents its nominal value a novel control strategy, which certain amount constant active can also be small or moderate happen. A Multiple second order generalized integrator frequency-locked loop synchronization algorithm employed estimate system frequency without harmonic distortions, as well output positive- negative- sequence αβ quantities voltages balanced unbalanced happen frequency- adaptive scheme. current stationary reference frame, guarantees cancellation distortions utility using Harmonic compensation structure, implementation protect DC link capacitor from thermal stresses avoiding appearance large at twice fundamental voltage. case study single-stage grid-connected PV maximum apparent about 500 kVA tested several simulations MATLAB/SIMULINK firstly, secondly, experiments Controller hardware-in-the-loop (CHIL) simulation technique for types do final validation algorithms.