In photovoltaic grid-connected system,the method of adding voltage feed-forward to improve the shape of grid-conected current wave is presented,the reason for the introduction of the net voltage feed-forward decreasing the phasic difference between grid-connected current and net voltage and reducing the THD of grid-connected current is analyzed.

To reduce the voltage distortion,current harmonics and torque ripple caused by the dead time effects,a voltage feed-forward dead time compensation method based on SVPWM is presented.

The neutral displacement voltage feed-forward control is introduced to the digital PI controller,which forces the inverter to output a voltage in real time to cancel out the effect of the interfering voltage and makes the inverter an ideal variable-frequency constant-current source.

The structure of the sine wave inverter is given,the working principles of the control circuit and voltage feedforward are analyzed.

In this paper, the influence to APF caused by the voltage fluctuating is analyzed, and a voltage feed-forward control method of APF is proposed.

Predictive voltage feedback PI controller with feedforward voltage compensator is adopted as the controlled method of the inverter system.

The research on the voltage feed-forward control method of shunt active power filter;