The invention discloses a feedforward control method for improving the adaptability of an LCL type grid-connected
inverter to a
power grid. The method comprises the steps that 1, a
capacitance current ic, a network connecting current ig and a grid-connected point
voltage vpcc are detected to obtain sampling signals ics, igs and vgs of the
capacitance current ic, the networking current ig and the grid-connected point
voltage vpcc; 2, the sampling signals are input to a current controller, and vrl is output after operational
processing; 3, the
signal vgs is input into a grid-connected
coupling point
voltage low-order
harmonic selector, and vr2 is output through
data processing; 4, vr1 and vr2 are added, a modulation
signal vm is obtained and input to a PWM generator, and a PWM
signal is generated to control a switching tube of an
inverter topology. Feedforward control is carried out by selecting grid-connected point voltage low-order background
harmonics, the stability of a grid-connected inversion
system and
power grid voltage low-order background
harmonic suppression are considered, and the adaptability of the
system to the
power grid impedance wide range changes is improved.